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Sample records for biological damage due

  1. Changes of color coordinates of biological tissue with superficial skin damage due to mechanical trauma

    Science.gov (United States)

    Pteruk, Vail; Mokanyuk, Olexander; Kvaternuk, Olena; Yakenina, Lesya; Kotyra, Andrzej; Romaniuk, Ryszard S.; Dussembayeva, Shynar

    2015-12-01

    Change of color coordinates of normal and pathological biological tissues is based on calculated spectral diffuse reflection. The proposed color coordinates of normal and pathological biological tissues of skin provided using standard light sources, allowing accurately diagnose skin damage due to mechanical trauma with a blunt object for forensic problems.

  2. Coupled analysis of building damage due to tunneling

    NARCIS (Netherlands)

    Giardina, G.; Hendriks, M.A.N.; Rots, J.G.

    2009-01-01

    Excavation works in urban areas require a preliminary risk damage assessment. In historical cities, the prediction of building response to settlements is necessary to reduce the risk of damage of the architectural heritage. The current method used to predict the building damage due to ground deforma

  3. Bacterial Cell Surface Damage Due to Centrifugal Compaction

    NARCIS (Netherlands)

    Peterson, Brandon W.; Sharma, Prashant K.; van der Mei, Henny C.; Busscher, Henk J.

    2012-01-01

    Centrifugal damage has been known to alter bacterial cell surface properties and interior structures, including DNA. Very few studies exist on bacterial damage caused by centrifugation because of the difficulty in relating centrifugation speed and container geometry to the damage caused. Here, we pr

  4. MRI findings of brain damage due to neonatal hypoglycemia

    International Nuclear Information System (INIS)

    Objective: To report the MRI findings of brain damage observed in neonatal patients who suffered from isolated hypoglycemia and to explore the value of diffusion-weighted imaging(DWI) in early detection of neonatal hypoglycemic brain injury. Methods: Twelve neonates with isolated hypoglycemia (10 of the 12 were diagnosed to suffer from hypoglycemic encephalopathy) were enrolled in this study. They were first scanned at age from 3 days to 10 days with T1WI, T2WI and DWI(b is 0 s/mm2, 1000 s/mm2), and 4 of them were then scanned from 7 days to 10 days following the initial scan. All acquired MR images were retrospectively analysed. Results: First series of DWI images showed distinct hyperintense signal in 11 cases in several areas including bilateral occipital cortex (2 cases), right occipital cortex (1 case), left occipital cortex and subcortical white matter(1 case), bilateral occipital cortex and subcortical white matter (2 cases), bilateral parieto-occipital cortex (2 cases), bilateral parieto-occipital cortex and subcortical white matter(2 cases), the splenium of corpus callosum (4 cases), bilateral corona radiata( 2 cases), left caudate nucleus and globus pallidus (1 case), bilateral thalamus (1 case), bilaterally posterior limb of internal capsule (1 case). In the initial T1WI and T2WI images, there were subtle hypointensity in the damaged cortical areas (3 cases), hyperintensity in the bilaterally affected occipital cortex( 1 case) on T1 weighted images, and hyperintensity in the affected cortex and subcortical white matter with poor differentiation on T2 weighted images. The followed-up MRI of 4 cases showed regional encephalomalacia in the affected occipital lobes(4 cases), slightly hyperintensity on T2 weighted images in the damaged occipital cortex (2 cases), extensive demyelination (1 case), disappearance of hyperintensity of the splenium of corpus callosum (1 case), and persistent hyperintensity in the splenium of corpus callosum (1 case) on T2 weighted

  5. Deterioration of Damselfly Flight Performance due to Wing Damage

    CERN Document Server

    Ren, Yan; Gai, Kuo; Li, Chengyu; Zeyghami, Samane; Dong, Haibo

    2011-01-01

    In this video, effect of chordwise damage on a damselfly (American Rubyspot)'s wings is investigated. High speed photogrammetry was used to collect the data of damselflies' flight with intact and damaged wings along the wing chord. Different level of deterioration of flight performance can be observed. Further investigation will be on the dynamic and aerodynamic roles of each wing with and without damage.

  6. From ozone depletion to biological UV damage

    Energy Technology Data Exchange (ETDEWEB)

    Tamm, E.; Thomalla, E.; Koepke, P. [Munich Univ. (Germany). Meteorological Inst.

    1995-12-31

    Based on the ozone data from the Meteorological Observatory Hohenpeissenberg (MOHP: 47.8 deg N, 11.01 deg E) and corresponding mean atmospheric conditions, high resolution UV spectra are calculated with a complex radiation transfer model STAR. Biologically weighted UV spectra are investigated as integrated irradiances (dose rates) for maximum zenith angles and as daily integrals for selected days of the year. Ozone variation and uncertainty of action spectra are investigated

  7. Damage costs due to bedload transport processes in Switzerland

    Science.gov (United States)

    Badoux, A.; Andres, N.; Turowski, J. M.

    2014-02-01

    In Alpine regions, floods are often associated with erosion, transport and deposition of coarse sediment along the streams. These processes are related to bedload transport and pose a hazard in addition to the elevated water discharge. However, it is unclear to what extent they contribute to total damage caused by natural hazards. Using the Swiss flood and landslide damage database - which collects financial damage data of naturally triggered floods, debris flows and landslides - we estimated the contribution of fluvial bedload transport processes to total damage costs in Switzerland. For each database entry an upper and lower limit of financial losses caused by or related to bedload transport processes was estimated, and the quality of the estimate was judged. When compared to total damage, the fraction of bedload transport damage in the 40 yr study period lies between 0.32 and 0.37. However, this value is highly variable for individual years (from 0.02 to 0.72). Bedload transport processes have induced cumulative financial losses between CHF 4.3 and 5.1 billion. Spatial analysis revealed a considerable heterogeneous distribution with largest damage for mountainous regions. The analysis of the seasonal distribution shows that more than 75 % of the bedload damage costs occurs in summer (June-August), and ∼ 23% in autumn (September-November). With roughly 56 %, by far most of the damage has been registered in August. Bedload transport processes are presently still inadequately understood, and the predictive quality of common bedload equations is often poor. Our analysis demonstrates the importance of bedload transport as a natural hazard and financial source of risk, and thus the need for future structured research on transport processes in steep streams.

  8. Secondary athrocytotic cardiomyopathy--heart damage due to Wilson's disease.

    Science.gov (United States)

    Kaduk, B; Metze, K; Schmidt, P F; Brandt, G

    1980-01-01

    Post-mortem atomic absorption spectrophotometry of the myocardium of a 14-year-old boy revealed a hundred-fold increase in copper. Further electrolyte analysis of the myocardium showed changes corresponding to metabolic heart muscle damage. Ultrastructural examination showed all the feature of a cardiomyopathy at the cellular level. Laser-Microprobe-Mass-Analysis demonstrated an inhomogeneous distribution of copper. An essential factor in the mechanism of death is heart damage.

  9. Videodensitometry in rats with pulmonary damage due to microembolism

    Energy Technology Data Exchange (ETDEWEB)

    Wegenius, G.; Wegener, T.; Ruhn, G.; Saldeen, T.; Erikson, U.

    Serial pulmonary angiography with videodensitometry was performed in 18 rats with pulmonary damage caused by administration of a fibrinolysis inhibitor, tranexamic acid (200 mg/kg body weight injected intraperitoneally) and bovine thrombin (500 NIH/kg body weight injected into the right femoral vein). The mean transit time (MTT) was calculated from videodensitometry, the observed area of interest consisting of approximately one-third of the right lung, including both central and peripheral parts. The impact of the pulmonary damage was analysed by morphologic methods and correlated to MTT. Although a pressure rise presumably occurred in the pulmonary circulation, no change in MTT was found after induction of pulmonary damage, indicating opening of actual and potential anastomoses between pulmonary arterioles and venules to serve as by-pass portions and as a safety-valve mechanism for the capillary bed and the right heart, respectively. Another explanation to unchanged MTT may be opening of resting capillary beds. Two rats with very severe pulmonary damage showed prolonged MTT. These rats may have suffered from cardiac failure.

  10. The DNA-damage response in human biology and disease

    DEFF Research Database (Denmark)

    Jackson, Stephen P; Bartek, Jiri

    2009-01-01

    , signal its presence and mediate its repair. Such responses, which have an impact on a wide range of cellular events, are biologically significant because they prevent diverse human diseases. Our improving understanding of DNA-damage responses is providing new avenues for disease management....

  11. Feather damage due to mycotic infections in wild turkeys.

    Science.gov (United States)

    Davidson, W R; Shotts, E B; Teska, J; Moreland, D W

    1989-10-01

    Wild turkeys (Meleagris gallopavo) from Pearl River Wildlife Management Area, St. Tammany Parish and from adjacent St. Helena Parish, Louisiana (USA) were observed to have broken and frayed rectrices. The condition was noted in 21% of 90 wild turkeys harvested by hunters during the springs of 1985 through 1988 from the Pearl River Wildlife Management Area. Damage to feathers ranged from mild to severe. Histologic and microbiologic study of five birds disclosed colonization and invasion of the rachis sheath and pulp by fungi of the genera Aspergillus, Curvularia, Cladosporium, Dactylella, Exophiala, Helminthosporium and Trichophyton and by Streptomyces. Sterilized normal rectrices from wild turkeys were inoculated with these organisms and subsequently developed damage that was histologically compatible with field cases. The condition was diagnosed as a multiple etiology mycosis. Successful colonization and invasion of experimentally inoculated feathers required addition of moisture and elevation of relative humidity within the cultures. The apparent high moisture requirements of the fungi suggest that late winter and early spring flooding may be a probable predisposing factor for this condition.

  12. Biological rhythms for rehabilitation of radiation damage of population

    International Nuclear Information System (INIS)

    Considerable disturbances in biological eurhythmycal structure of redoracu were discovered for people living in Borodulikha area of the Semipalatinsk test site. The deep desynchronise may result in a development of the cardiovascular, bronco-pulmonary, endocrine, oncologic, neuro psychic diseases. A method to correct the biological eurhythmycal structure was developed. Homeopathic doses of melatonin ('rhythm driver' managing the most regenerating and immune systems) and uthynol (promoting production of dehydroepiandrosterone of maternal prehormone of 27 hormones) were used to provide the general correction. The endocrine diseases are not practically subjected to the homeopathic correction. The sub correction was sometimes carried out after 5 months. The developed methods of rehabilitation of the radiation damages are unique, since they allow performing the homeopathic correction using the acupuncture monitoring

  13. Damages and Expected Deaths Due to Excess NOx Emissions from 2009 to 2015 Volkswagen Diesel Vehicles.

    Science.gov (United States)

    Holland, Stephen P; Mansur, Erin T; Muller, Nicholas Z; Yates, Andrew J

    2016-02-01

    We estimate the damages and expected deaths in the United States due to excess emissions of NOx from 2009 to 2015 Volkswagen diesel vehicles. Using data on vehicle registrations and a model of pollution transport and valuation, we estimate excess damages of $430 million and 46 excess expected deaths. Accounting for uncertainty about emissions gives a range for damages from $350 million to $500 million, and a range for excess expected deaths from 40 to 52. Our estimates incorporate significant local heterogeneity: for example, Minneapolis has the highest damages despite having fewer noncompliant vehicles than 13 other cities. Our estimated damages greatly exceed possible benefits from reduced CO2 emissions due to increased fuel economy. PMID:26720281

  14. Damages and Expected Deaths Due to Excess NOx Emissions from 2009 to 2015 Volkswagen Diesel Vehicles.

    Science.gov (United States)

    Holland, Stephen P; Mansur, Erin T; Muller, Nicholas Z; Yates, Andrew J

    2016-02-01

    We estimate the damages and expected deaths in the United States due to excess emissions of NOx from 2009 to 2015 Volkswagen diesel vehicles. Using data on vehicle registrations and a model of pollution transport and valuation, we estimate excess damages of $430 million and 46 excess expected deaths. Accounting for uncertainty about emissions gives a range for damages from $350 million to $500 million, and a range for excess expected deaths from 40 to 52. Our estimates incorporate significant local heterogeneity: for example, Minneapolis has the highest damages despite having fewer noncompliant vehicles than 13 other cities. Our estimated damages greatly exceed possible benefits from reduced CO2 emissions due to increased fuel economy.

  15. Biological effects due to weak magnetic fields on plants

    Science.gov (United States)

    Belyavskaya, N.

    In the evolution process, living organisms have experienced the action of the Earth's magnetic field (MF) that is a natural component of our environment. It is known that a galactic MF induction does not exceed 0.1 nT, since investigations of weak magnetic field (WMF) effects on biological systems have attracted attention of biologists due to planning long-term space flights to other planets where the magnetizing force is near 10-5 Oe. However, the role of WMF and its influence on organisms' functioning are still insufficiently investigated. A large number of experiments with seedlings of different plant species placed in WMF has found that the growth of their primary roots is inhibited during the early terms of germination in comparison with control. The proliferation activity and cell reproduction are reduced in meristem of plant roots under WMF application. The prolongation of total cell reproductive cycle is registered due to the expansion of G phase in1 different plant species as well as of G phase in flax and lentil roots along with2 relative stability of time parameters of other phases of cell cycle. In plant cells exposed to WMF, the decrease in functional activity of genome at early prereplicate period is shown. WMF causes the intensification in the processes of proteins' synthesis and break-up in plant roots. Qualitative and quantitative changes in protein spectrum in growing and differentiated cells of plant roots exposed to WMF are revealed. At ultrastructural level, there are observed such ultrastructural peculiarities as changes in distribution of condensed chromatin and nucleolus compactization in nuclei, noticeable accumulation of lipid bodies, development of a lytic compartment (vacuoles, cytosegresomes and paramural bodies), and reduction of phytoferritin in plastids in meristem cells of pea roots exposed to WMF. Mitochondria are the most sensitive organelle to WMF application: their size and relative volume in cells increase, matrix is electron

  16. Biological effects due to weak magnetic field on plants

    Science.gov (United States)

    Belyavskaya, N. A.

    2004-01-01

    Throughout the evolution process, Earth's magnetic field (MF, about 50 μT) was a natural component of the environment for living organisms. Biological objects, flying on planned long-term interplanetary missions, would experience much weaker magnetic fields, since galactic MF is known to be 0.1-1 nT. However, the role of weak magnetic fields and their influence on functioning of biological organisms are still insufficiently understood, and is actively studied. Numerous experiments with seedlings of different plant species placed in weak magnetic field have shown that the growth of their primary roots is inhibited during early germination stages in comparison with control. The proliferative activity and cell reproduction in meristem of plant roots are reduced in weak magnetic field. Cell reproductive cycle slows down due to the expansion of G 1 phase in many plant species (and of G 2 phase in flax and lentil roots), while other phases of cell cycle remain relatively stabile. In plant cells exposed to weak magnetic field, the functional activity of genome at early pre-replicate period is shown to decrease. Weak magnetic field causes intensification of protein synthesis and disintegration in plant roots. At ultrastructural level, changes in distribution of condensed chromatin and nucleolus compactization in nuclei, noticeable accumulation of lipid bodies, development of a lytic compartment (vacuoles, cytosegresomes and paramural bodies), and reduction of phytoferritin in plastids in meristem cells were observed in pea roots exposed to weak magnetic field. Mitochondria were found to be very sensitive to weak magnetic field: their size and relative volume in cells increase, matrix becomes electron-transparent, and cristae reduce. Cytochemical studies indicate that cells of plant roots exposed to weak magnetic field show Ca 2+ over-saturation in all organelles and in cytoplasm unlike the control ones. The data presented suggest that prolonged exposures of plants to weak

  17. Energy Change due to Off-Fault Damage Evolution associated with Dynamic Fault Tip Growth

    Science.gov (United States)

    Suzuki, T.

    2010-12-01

    We theoretically study off-fault damage evolution effects on dynamic earthquake rupture, especially from a standpoint of energy change in a whole system. The importance of off-fault inelastic energy loss due to damage on dynamic earthquake rupture has attracted interests of many researchers in terms of, for example, rupture velocity reduction and crack tip growth cessation. The damage effect is found to be important on dynamic earthquake slip behavior in terms of porosity increase also in a series of our previous studies, Suzuki and Yamashita (2007; 2008; 2009; 2010). The mathematical formulation of Murakami and Kamiya (1997) is assumed in the present study; the damage tensor D is used to describe damage state in a medium. Damage, which consists of microcracks in a medium, has direction (defined as normal to the crack surface) and the magnitude (crack size), so that a scalar damage variable is insufficient to describe the damage state. We first analytically derive the equation system including the damage tensor and describing energy change in a whole system due to any dynamic elastic and inelastic deformation processes such as macroscopic crack extension and damage evolution. The change in the summation of strain and kinetic energies and damage energy is found to be equal to the summation of energy flowing out of the medium through the boundary and energy turning to heat and irreversibly lost based on the analytical expression; the damage energy is associated with surface energy released by damage evolution. The damage energy is confirmed to be equal to the summation of the loss in strain energy due to change in the elastic moduli and irreversibly lost energy. A mode III crack embedded in a medium causing damage is then assumed to study the off-fault damage effects on dynamic earthquake rupture. Spontaneous crack tip growth with the Coulomb fracture criterion is assumed and in such a case the rupture velocity can be sufficiently smaller than the terminal velocity

  18. Pressure pulse induced-damage in live biological samples

    Directory of Open Access Journals (Sweden)

    Rankin S.M.

    2012-08-01

    Full Text Available Developing a cellular and molecular understanding of the nature of traumatic and post-traumatic effects of blast on live biological samples is critical for improving clinical outcomes. To analyze the effects of blast waves upon the cellular structures and the underlying physiological and biochemical changes, we have constructed an experimental platform capable of delivering compression waves, of amplitudes relevant to blast, to cell suspensions in a contained environment. Initial characterization of the system shows that cell cultures can be subjected to high-intensity compression waves up to 15 MPa in pressure and duration of 80 ± 10μs. Studies of mouse mesenchymal stem cells subjected to two different pressure impulses were analysed by cell counting, cell viability assays and microscopic evaluation: the experiments present evidence suggestive of increased levels of damage and loss of cellular integrity compared to uncompressed cell cultures.

  19. Structural Modifications in Fused Silica Due to Laser Damage Induced Shock Compression

    Energy Technology Data Exchange (ETDEWEB)

    Kubota, A; Davila, L; Caturla, M J; Stolken, J S; Sadigh, B; Quong, A; Rubenchik, A; Feit, M D

    2001-12-05

    High power laser pulses can produce damage in high quality fused silica optics that can lead to its eventual obscuration and failure. Current models suggest the initiation of a plasma detonation due to absorbing initiators and defects, leading to the formation of shock waves. Recent experiments have found a densified layer at the bottom of damage sites, as evidence of the laser-damage model. We have studied the propagation of shock waves through fused silica using molecular dynamics. These simulations show drastic modifications in the structure and topology of the network, in agreement with experimental observations.

  20. Radiation-induced cardiac damage in early left breast cancer patients: Risk factors, biological mechanisms, radiobiology, and dosimetric constraints

    International Nuclear Information System (INIS)

    Today there is general awareness of the potential damage to the heart in left-sided (more than in right-sided) breast cancer radiotherapy (RT). Historical changes in tumor and heart doses are presented here along with the impact of different RT techniques and volumes. Individual and pharmacological risk factors are also examined with respect to radiation damage. The biological mechanisms of harm are only partially understood, such as the radiobiology of heart damage due to the presence of various radiosensitive structures and their topographic heterogeneity. Furthermore, individual variability may expose patients to higher or lower risks of late cardiac damage or death. Damage mechanisms and radiobiological characteristics in heart irradiation are presented in relation to dosimetric and biological parameters.

  1. DNA damage in human lymphocytes due to synergistic interaction between ionizing radiation and pesticide

    International Nuclear Information System (INIS)

    Biological risks may arise from the possibility of the synergistic interaction between harmful factors such as ionizing radiation and pesticide. The effect of pesticide on radiation-induced DNA damage in human in human blood lymphocytes was evaluated by the single cell gel electrophoresis (SCGE) assay. The lymphocytes, with or without pretreatment of the pesticide, were exposed to 2.0 Gy of gamma ray. Significantly increased tail moment, which was a marker of DNA strand breaks in SCGE assay, showed an excellent dose-response relationship. The present study confirms that the pesticide has the cytotoxic effect on lymphocytes and that it interacts synergistically with ionizing radiationon DNA damage, as well

  2. Modeling Reservoir Formation Damage due to Water Injection for Oil Recovery

    DEFF Research Database (Denmark)

    Yuan, Hao

    2010-01-01

    The elliptic equation for non-Fickian transport of suspension in porous media is applied to simulate the reservoir formation damage due to water injection for oil recovery. The deposition release (erosion of reservoir formation) and the suspension deposition (pore plugging) are both taken into ac...

  3. Failure analysis of a bearing in a helicopter turbine engine due to electrical discharge damage

    Directory of Open Access Journals (Sweden)

    Michael K. Budinski

    2014-10-01

    Full Text Available This article documents the metallurgical evaluation of a rolling element bearing that failed due to electrical discharge damage. This rolling element bearing was used in a helicopter turbine engine that failed in-flight, resulting in a hard landing of the helicopter. Optical and electron microscopy as well as energy dispersive spectroscopy were used to evaluate the bearing. Pitting and material transfer on the external bearing races bearing and mating surfaces revealed that the electrical discharge damage occurred while the engine's components were not rotating.

  4. Dynamics of hydraulic properties due to biological clogging

    Science.gov (United States)

    Rosenzweig, R.; Shavit, U.; Furman, A.

    2012-04-01

    Classic treatment of soil-water flow is described by the unsaturated version of Darcy's law and Richards' equation, assuming time invariant hydraulic properties, e.g. the saturated hydraulic conductivity, Ks, and van Genuchten-Mualem's α and n. However, when bacteria is present the soil is quite far from being time invariant and biological activity constantly alters the pore-scale structure, leading to macro-scale alteration of the hydraulic properties. This may be of high relevance to processes such as subsurface bioremediation, soil aquifer treatment, wastewater irrigation, and more. In this work we explore the dynamic alteration of soil hydraulic properties by a combination of column experiments and pore-network modeling. We experimentally demonstrate how biological activity clogs an unsaturated soil column and reduces its hydraulic conductivity, while a similar column where biological activity is limited does not clog. Further, we demonstrate that the clogging is preferential to the nutrient input. Next, we develop a pore-network model that uses triangular shape channels. This allows a dual occupancy (water-air) of each channel and high connectivity. The model solves the flow of water, nutrient transport, and biological dynamics. It includes biofilm growth and decay, attachment and detachment, and nutrient exchange between the water and biofilm phases. We perform a sensitivity analysis of the model and qualitatively show through the loss of connectivity how the clogging that was observed in our experiment can be explained.

  5. New perspectives on the damage estimation for buried pipeline systems due to seismic wave propagation

    Energy Technology Data Exchange (ETDEWEB)

    Pineda Porras, Omar Andrey [Los Alamos National Laboratory

    2009-01-01

    Over the past three decades, seismic fragility fonnulations for buried pipeline systems have been developed following two tendencies: the use of earthquake damage scenarios from several pipeline systems to create general pipeline fragility functions; and, the use of damage scenarios from one pipeline system to create specific-system fragility functions. In this paper, the advantages and disadvantages of both tendencies are analyzed and discussed; in addition, a summary of what can be considered the new challenges for developing better pipeline seismic fragility formulations is discussed. The most important conclusion of this paper states that more efforts are needed to improve the estimation of transient ground strain -the main cause of pipeline damage due to seismic wave propagation; with relevant advances in that research field, new and better fragility formulations could be developed.

  6. WILD PIGS: BIOLOGY, DAMAGE, CONTROL TECHINQUES AND MANAGEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, John; Brisbin, I. Lehr

    2009-12-31

    about anything; and, they can live just about anywhere. On top of that, wild pigs are both very difficult to control and, with the possible exception of island ecosystems, almost impossible to eradicate (Dickson et al. 2001, Sweeney et al. 2003). The solution to the wild pig problem has not been readily apparent. The ultimate answer as to how to control these animals has not been found to date. In many ways, wild pigs are America's most successful large invasive species. All of which means that wild pigs are a veritable nightmare for land and resource managers trying to keep the numbers of these animals and the damage that they do under control. Since the more that one knows about an invasive species, the easier it is to deal with and hopefully control. For wild pigs then, it is better to 'know thy enemy' than to not, especially if one expects to be able to successfully control them. In an effort to better 'know thy enemy,' a two-day symposium was held in Augusta, Georgia, on April 21-22, 2004. This symposium was organized and sponsored by U.S.D.A. Forest Service-Savannah River (USFS-SR), U. S. Department of Energy-Savannah River Operations Office (DOE-SR), the Westinghouse Savannah River Company (WSRC), the South Carolina Chapter of the Soil & Water Conservation Society, and the Savannah River Ecology Laboratory (SREL). The goal of this symposium was to assemble researchers and land managers to first address various aspects of the biology and damage of wild pigs, and then review the control techniques and management of this invasive species. The result would then be a collected synopsis of what is known about wild pigs in the United States. Although the focus of the symposium was primarily directed toward federal agencies, presenters also included professionals from academic institutions, and private-sector control contractors and land managers. Most of the organizations associated with implementing this symposium were affiliated with the

  7. WILD PIGS: BIOLOGY, DAMAGE, CONTROL TECHINQUES AND MANAGEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, John; Brisbin, I. Lehr

    2009-12-31

    about anything; and, they can live just about anywhere. On top of that, wild pigs are both very difficult to control and, with the possible exception of island ecosystems, almost impossible to eradicate (Dickson et al. 2001, Sweeney et al. 2003). The solution to the wild pig problem has not been readily apparent. The ultimate answer as to how to control these animals has not been found to date. In many ways, wild pigs are America's most successful large invasive species. All of which means that wild pigs are a veritable nightmare for land and resource managers trying to keep the numbers of these animals and the damage that they do under control. Since the more that one knows about an invasive species, the easier it is to deal with and hopefully control. For wild pigs then, it is better to 'know thy enemy' than to not, especially if one expects to be able to successfully control them. In an effort to better 'know thy enemy,' a two-day symposium was held in Augusta, Georgia, on April 21-22, 2004. This symposium was organized and sponsored by U.S.D.A. Forest Service-Savannah River (USFS-SR), U. S. Department of Energy-Savannah River Operations Office (DOE-SR), the Westinghouse Savannah River Company (WSRC), the South Carolina Chapter of the Soil & Water Conservation Society, and the Savannah River Ecology Laboratory (SREL). The goal of this symposium was to assemble researchers and land managers to first address various aspects of the biology and damage of wild pigs, and then review the control techniques and management of this invasive species. The result would then be a collected synopsis of what is known about wild pigs in the United States. Although the focus of the symposium was primarily directed toward federal agencies, presenters also included professionals from academic institutions, and private-sector control contractors and land managers. Most of the organizations associated with implementing this symposium were affiliated with the

  8. A QUANTITATIVE DISCRETE ELEMENT MODEL TO INVESTIGATE SUB-SURFACE DAMAGE DUE TO SURFACE POLISHING

    OpenAIRE

    André, Damien; Iordanoff, Ivan; Charles, Jean-Luc; NÉAUPORT, Jérôme

    2012-01-01

    This work is a continuation of a previous study that investigated sub-surface damage in silica glass due to surface polishing. In this previous study, discrete element models have shown qualitatively good agreement with experiments. The presented work propose a model allowing quantitative results by focusing on the continuous part of the problem. Special attemption was given to the discrete element model of silica glass considered as perfectly isotropic, elastic and brittle. To validate this ...

  9. Delineating the DNA damage response using systems biology approaches

    NARCIS (Netherlands)

    Stechow, Louise von

    2013-01-01

    Cellular responses to DNA damage are highly variable and strongly depend on the cellular and organismic context. Studying the DNA damage response is crucial for a better understanding of cancer formation and ageing as well as genotoxic stress-induced cancer therapy. To do justice to the multifaceted

  10. Parametric Study of Damage Evaluation into Solid Dielectrics Due to PD Activity Using a Kinetic Model

    Directory of Open Access Journals (Sweden)

    Alireza Ganjovi

    2014-09-01

    Full Text Available A kinetic model is used based on Particle in Cell - Monte Carlo Collision (PIC-MCC model, for parametric study of the damage due to partial discharges (PD activity into the surroundings dielectrics of a narrow channel encapsulated within the volume of a dielectric material. The parameters studied are applied electric field, channel dimensions and gas pressure. After employing an electric field across a dielectric material which contains a narrow channel, repeated ionization process starts in the gaseous medium of narrow channel. Charged particles, especially electrons, gain energy from the electric field across narrow channel and cause damage into dielectric surfaces of narrow channel on impact. The dependence of the electron energy distribution function (EEDF on the applied electric field is considered. These estimations are performed based on the number of C-H bond-scissions produced by the impacting electrons of a single PD pulse. Regarding this technique, the consequent damage into the solid dielectric and the time required to increase surface conductivity, is computed. The formation of acid molecules due to interaction of PD pulse with polymer surface in presence of air and humidity causes changes in the surface conductivity of the surrounding dielectrics of the narrow channels. It is observed that the extent of damage caused by a PD is primarily determined by the total number of impacting electrons which are capable of producing bond-scission at the dielectric. Parameters that effectively cause an increase in the number of energetic electrons will increase effective damage as well as surface conductivity of surrounding dielectrics.

  11. Damage costs due to automotive air pollution and the influence of street canyons

    International Nuclear Information System (INIS)

    Using the methodology of the ExternE Project of the European Commission, we have evaluated the damage costs of automotive air pollution by way of two case studies in France: a trip across Paris, and a trip from Paris to Lyon. This methodology involves an analysis of the impact pathways, starting with the emissions (e.g., g/km of particles form tailpipe), followed by local and regional dispersion (e.g., incremental μg/m3 of particles), calculation of the physical impacts using exposure-response functions (e.g., cases of respiratory hospital admissions), and finally multiplication by unit costs factors (e.g., ε per hospital admission). Damages are aggregated over all affected receptors in Europe. In addition to the local and regional dispersion calculations carried out so far by ExternE, we also consider the increased microscale impacts due to the trapping of pollutants in street canyons, using numerical simulations with the FLUENT software. We have evaluated impacts to human health, agricultural crops and building materials, due to particles, NOx, CO, HC and CO2. Health impacts, especially reduced life expectancy, dominate in terms of cost. Damages for older cars (before 1997) range from 2 to 41Euro cents/km, whereas for newer cars (since 1997), the range 1-9 Euro cents/km, and there is continuing progress in reducing the emissions further. In large cities, the particulate emissions of diesel cars lead to the highest damages, exceeding those of gasoline cars by a factor of 7. For cars before 1997 the order of magnitude of the damage costs is comparable to the price of gasoline, and the loss of life expectancy is comparable to that from traffic accidents. (Author)

  12. Relative Biological Effectiveness and Peripheral Damage of Antiproton Annihilation

    CERN Multimedia

    Kavanagh, J N; Kaiser, F; Tegami, S; Schettino, G; Kovacevic, S; Hajdukovic, D; Welsch, C P; Currell, F J; Toelli, H T; Doser, M; Holzscheiter, M; Herrmann, R; Timson, D J; Alsner, J; Landua, R; Knudsen, H; Comor, J; Moller, S P; Beyer, G

    2002-01-01

    The use of ions to deliver radiation to a body for therapeutic purposes has the potential to be significant improvement over the use of low linear energy transfer (LET) radiation because of the improved energy deposition profile and the enhanced biological effects of ions relative to photons. Proton therapy centers exist and are being used to treat patients. In addition, the initial use of heavy ions such as carbon is promising to the point that new treatment facilities are planned. Just as with protons or heavy ions, antiprotons can be used to deliver radiation to the body in a controlled way; however antiprotons will exhibit additional energy deposition due to annihilation of the antiprotons within the body. The slowing down of antiprotons in matter is similar to that of protons except at the very end of the range beyond the Bragg peak. Gray and Kalogeropoulos estimated the additional energy deposited by heavy nuclear fragments within a few millimeters of the annihilation vertex to be approximately 30 MeV (...

  13. Damage Characteristics of the Logical Chip Module Due to Plasma Created by Hypervelocity Impacts

    Science.gov (United States)

    Tang, Enling; Wu, Jin; Wang, Meng; Zhang, Lijiao; Xiang, Shenghai; Xia, Jin; Liu, Shuhua; He, Liping; Han, Yafei; Xu, Mingyang; Zhang, Shuang; Yuan, Jianfei

    2016-04-01

    To researching the damage characteristics of typical logical chip modules in spacecraft due to plasma generated by hypervelocity impacts, we have established a triple Langmuir probe diagnostic system and a logical chips measurement system, which were used to diagnose plasma characteristic parameters and the logical chip module's logical state changes due to the plasma created by a 7075 aluminum projectile hypervelocity impact on the 2A12 aluminum target. Three sets of experiments were performed with the collision speeds of 2.85 km/s, 3.1 km/s and 2.20 km/s, at the same incident angles of 30 degrees and logical chip module's positions by using a two-stage light gas gun loading system, a plasma characteristic parameters diagnostic system and a logical chip module's logical state measurement system, respectively. Electron temperature and density were measured at given position and azimuth, and damage estimation was performed for the logical chip module by using the data acquisition system. Experimental results showed that temporary damage could be induced on logical chip modules in spacecraft by plasma generated by hypervelocity impacts under the given experimental conditions and the sensors' position and azimuth. supported by National Natural Science Foundation of China (Nos. 10972145, 11272218, 11472178), Program for Liaoning Excellent Talents in University of China (No. LR2013008), Open Foundation of Key Laboratory of Liaoning Weapon Science and Technology, Liaoning Province Talents Engineering Projects of China (No. 2012921044)

  14. Protection of works of art from damage due to photochemical smog: progress report through September 1985

    OpenAIRE

    Cass, Glen; Grosjean, Daniel; Nazaroff, William; Whitmore, Paul; Druzik, James

    1985-01-01

    Experiments conducted in the early 1980's on a very small selection of modern artists' pigments showed that several pigments will fade dramatically if exposed to ozone at the levels found in Los Angeles photochemical smog. The objective of this research project is to provide a comprehensive assessment of the full scope of this fading hazard to works of art, and to determine the methods that can be used to protect works of art from damage due to photochemical oxidants. In order to achieve this...

  15. Effect of Oxidative Damage Due to Excessive Protein Ingestion on Pancreas Function in Mice

    OpenAIRE

    Huiyong Xu; Chunmei Gu

    2010-01-01

    The present study was undertaken to evaluate the effect of oxidative damage due to excessive protein diet on pancreas function in mice. For this purpose, thirty male (C57BL/6J) mice were randomly divided into three groups and fed on different diets as follows: group 1 was fed on a normal diet, group 2 was fed on an excessive protein diet and group 3 was fed on an excessive protein diet supplemented with 0.06 g/kg cysteamine. Each group was fed for 2 weeks, and then pancreas samples were colle...

  16. Methodology for the assessment of possible damages in low voltage equipment due to lightning surges

    Energy Technology Data Exchange (ETDEWEB)

    Matsuo, Nelson M.; Kagan, Nelson [University of Sao Paulo (USP), SP (Brazil)], Emails: matsuonm@usp.br, nelsonk@pea.usp.br; Domingues, Ivo T. [AES Eletropaulo, SP (Brazil); Jesus, Nelson C. de [AES Sul, Porto Alegre, RS (Brazil); Silva, Marcelo H.I. da [Grupo Rede, Sao Paulo, SP (Brazil); Takauti, Edson H. [Bandeirante, Sao Paulo, SP (Brazil)

    2007-07-01

    This paper deals with the development of a methodology to assess the possibility of equipment damages in low voltage customers due to lightning surges. The main objective is to incorporate this methodology in a computation system that supports distribution companies to determine the possible causes of equipment damages claimed by customers and to decide whether the claims are to be reimbursed or not. The proposed methodology determines whether a specific customer could be affected by a lightning strike according to his/her location and to the lightning main parameters, by using data from a lightning detection system and from the specific equipment surge withstand capability. A specific study using ATP (Alternative Transients Program) was carried out to assess the propagation of lightning surges in electric power distribution systems and their impact over low voltage customers. On the other hand, the withstand capability of the main household appliances was determined by a series of tests carried out in the University's power quality laboratory. The paper details the modeling used for simulation, such as network configuration, grounding points, and modelling of insulator flashover, distribution transformer, low voltage loads. It also presents some results regarding the evaluation of over voltages in low voltage customers installations. A practical method is proposed for assessing the possibility of equipment damage and describes how the existing uncertainties were handled. Also, some issues regarding the withstand capability of electric household appliances to lightning surges are discussed and some results of the laboratory tests are presented. (author)

  17. Computed chest tomography in rats with pulmonary damage due to microembolism

    Energy Technology Data Exchange (ETDEWEB)

    Wegener, T.; Wegenius, G.; Hemmingsson, A.; Jung, B.; Saldeen, T.

    Computed chest tomography was performed in 13 rats with pulmonary damage due to microembolism, caused by injection of thrombin (500 NIH/kg body weight) and tranexamic acid, a fibrinolytic inhibitor (200 mg/kg body weight), and in 9 control rats. The purpose of the investigation was to perform attenuation measurements at two levels of the right lung, each with three regions of interest (anterior, mid and posterior). Alterations in attenuation, compared with controls, were correlated with lung weight. Compared with controls, the attenuation was significantly increased in the anterior and posterior regions at both levels in animals with pulmonary damage, but not in the mid regions. There was a statistically significant correlation between increasing attenuation and increasing lung weight. A significant difference was found between damaged and control lungs regarding the microscopic grade of interstitial oedema, alveolar oedema and fibrin. Histograms of attenuation values in computed tomograms might be of value in detecting alveolar oedema. It is concluded that computed chest tomography is a good method for detection pulmonary oedema at an early stage of experimental microembolism in the rat.

  18. Damage evaluation in metal structures subjected to high energy deposition due to particle beams

    CERN Document Server

    Peroni, L; Dallocchio, A

    2011-01-01

    The unprecedented energy intensities of modern hadron accelerators yield special problems with the materials that are placed close to or into the high intensity beams. The energy stored in a single beam of LHC particle accelerator is equivalent to about 80 kg of TNT explosive, stored in a transverse beam area with a typical value of 0.2 mm×0.2 mm. The materials placed close to the beam are used at, or even beyond, their damage limits. However, it is very difficult to predict structural efficiency and robustness accurately: beam-induced damage for high energy and high intensity occurs in a regime where practical experience does not exist. The interaction between high energy particle beams and metals induces a sudden non uniform temperature increase. This provokes a dynamic response of the structure entailing thermal stress waves and thermally induced vibrations or even the failure of the component. This study is performed in order to estimate the damage on a copper component due to the impact with a 7 TeV pro...

  19. Biology and damage of an undescribed baridine weevil on amryllis

    Science.gov (United States)

    The weevil subfamily Baridinae is comprised of several economically important species that cause damage to the roots and fruits of plants. In the early 1990's, a baradine weevil was observed feeding on and occasionally killing amaryllis (Hippeastrum Herb) plants in Florida. A survey was conducted to...

  20. Assessment of damage from reduction of expected lifespan due to cancer

    Directory of Open Access Journals (Sweden)

    Boris Alengordovich Korobitsyn

    2013-09-01

    Full Text Available This paper presents the theoretical and methodological approaches to the assessment of damage from premature mortality and reduction of life expectancy due to various reasons. The concepts measuring the price of a human life are analyzed: the evaluation from the standpoint of the theory of human capital; indirect estimation taking into account non-monetary social costs; evaluation of individuals’ willingness to pay for the elimination of the risk of death; estimation based on the determination of insurance premiums and compensations under court decision; evaluation of the social investments, aimed to reduce the risk of premature mortality of the individual. The following indexes were calculated for all subordinate entities of the Russian Federation: reduction of life expectancy, lost years of potential life in the working age, and gross regional product lost due to the reduction of years of potential life in the working-age population as a result of cancer

  1. Development of radiation biological dosimetry and treatment of radiation-induced damaged tissue

    International Nuclear Information System (INIS)

    Util now, only a few methods have been developed for radiation biological dosimetry such as conventional chromosome aberration and micronucleus in peripheral blood cell. However, because these methods not only can be estimated by the expert, but also have a little limitation due to need high technique and many times in the case of radiation accident, it is very difficult to evaluate the absorbed dose of victims. Therefore, we should develop effective, easy, simple and rapid biodosimetry and its guideline(triage) to be able to be treated the victims as fast as possible. We established the apoptotic fragment assay, PCC, comet assay, and micronucleus assay which was the significant relationship between dose and cell damages to evaluate the irradiated dose as correct and rapid as possible using lymphocytes and crypt cells, and compared with chromosome dosimetry and micronucleus assay

  2. Development of radiation biological dosimetry and treatment of radiation-induced damaged tissue

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Chul Koo; Kim, Tae Hwan; Lee, Yun Sil [and others

    2000-04-01

    Util now, only a few methods have been developed for radiation biological dosimetry such as conventional chromosome aberration and micronucleus in peripheral blood cell. However, because these methods not only can be estimated by the expert, but also have a little limitation due to need high technique and many times in the case of radiation accident, it is very difficult to evaluate the absorbed dose of victims. Therefore, we should develop effective, easy, simple and rapid biodosimetry and its guideline(triage) to be able to be treated the victims as fast as possible. We established the apoptotic fragment assay, PCC, comet assay, and micronucleus assay which was the significant relationship between dose and cell damages to evaluate the irradiated dose as correct and rapid as possible using lymphocytes and crypt cells, and compared with chromosome dosimetry and micronucleus assay.

  3. Surface damage of metallic implants due to mechanical loading and chemical reactions

    Science.gov (United States)

    Ryu, Jaejoong

    The present study investigates interfacial damage mechanism of modular implants due to synergetic action of mechanical contact loading and corrosion. Modular implants are manufactured such that surfaces have a characteristic degree of roughness determined by tool tip size and motion of tool path or feeding speed. The central hypothesis for this work is that during contact loading of metallic implants, mechanisms of damage and dissolution are determined by contact loads, plastic deformation, residual stresses and environmental conditions at the nanoscale surface asperities; while during subsequent rest periods, mechanism of metallic dissolution is determined by the environmental conditions and residual stress field induced due to long range elastic interactions of the plastically deformed asperities. First part of the thesis is focused on investigating the mechanisms underlying surface roughness evolution due to stress-assisted dissolution during the rest period. The latter part is focused on investigating material removal mechanisms during single asperity contact of implant surfaces. Experimental study was performed to elucidate the roughness evolution mechanism by combined effect of multi-asperity contact and environmental corrosion. Cobalt-chromium-molybdenum specimen was subjected to either contact loading alone or alternating contact loading and exposure to reactive environment. Roughness of the specimen surface was monitored by optical profilometry and Fast Fourier Transform (FFT) calculation was used to characterize the evolving behavior of roughness modes. Finite element analysis (FEA) was employed to identify influences of surface morphological configurations and contact pressures on the residual stress development. Analytical model of multi-asperity contact has been developed for prediction of residual stress field for different roughness configurations during varying magnitude of contact loads based on elastic inclusion theory. Experimental results

  4. Damage due to the Mw 7.7 Kutch, India earthquake of 2001

    Science.gov (United States)

    Rastogi, B. K.

    2004-10-01

    This paper presents a study of the damage due to the Mw 7.6-7.7 intraplate Kutch earthquake of 26 January 2001. It was a powerful earthquake with a high stress drop of about 20 MPa. Aftershocks (up to M 4) have continued for 2.5 years. The distribution of early aftershocks indicates a rupture plane of 20-25 km radius at depths of 10-45 km along an E-W-trending and south-dipping hidden fault situated approximately 25 km north of the Kutch Mainland Fault. The moment tensor solution determined from regional broadband data indicates reverse motion along a south-dipping (by 47°) fault. The earthquake is the largest event in India in the last 50 years and the most destructive in the recorded history in terms of socioeconomic losses with 13,819 deaths (including 14 in Pakistan), collapse/severe damage of over a million houses and US$10 billion economic loss. Surface faulting was not observed. However, intense land deformations have been observed in a 40×20-km meizoseismal area. These include lateral spreading, ground uplifts (about a meter), ground slumping and deep cracks. Liquefaction with ejection of sand and copious water was widespread in the Banni grassland, Rann areas (salt plains), along rivers and also in the coastal areas up to 200 km distance from the epicenter in areas of intensity VII to X+. Stray incidences of liquefaction have occurred up to distances of at least 300 km. For the first time in India, multistory buildings have been destroyed/damaged by an earthquake. The maximum acceleration is inferred to be 700 cm/s 2 and intensities are 1-3 units higher in soil-covered areas than expected from the decay rate of acceleration for hard rock.

  5. Pattern Learning, Damage and Repair within Biological Neural Networks

    Science.gov (United States)

    Siu, Theodore; Fitzgerald O'Neill, Kate; Shinbrot, Troy

    2015-03-01

    Traumatic brain injury (TBI) causes damage to neural networks, potentially leading to disability or even death. Nearly one in ten of these patients die, and most of the remainder suffer from symptoms ranging from headaches and nausea to convulsions and paralysis. In vitro studies to develop treatments for TBI have limited in vivo applicability, and in vitro therapies have even proven to worsen the outcome of TBI patients. We propose that this disconnect between in vitro and in vivo outcomes may be associated with the fact that in vitro tests assess indirect measures of neuronal health, but do not investigate the actual function of neuronal networks. Therefore in this talk, we examine both in vitro and in silico neuronal networks that actually perform a function: pattern identification. We allow the networks to execute genetic, Hebbian, learning, and additionally, we examine the effects of damage and subsequent repair within our networks. We show that the length of repaired connections affects the overall pattern learning performance of the network and we propose therapies that may improve function following TBI in clinical settings.

  6. Fatigue Crack Growth in Complex Residual Stress Fields Due to Surface Treatment and Foreign Object Damage under Simulated Flight Cycles

    OpenAIRE

    Zabeen, S.

    2011-01-01

    Foreign object damage (FOD) refers to the damage that generally takes place in aero engine fans and compressor blades, due to the ingestion of hard particles/debris during aeroplane take-off, taxiing, or landing. Such damage can reduce the fatigue life expectancy of the turbine engine components by 50%. Residual stresses and small microcracks induced by the high speed FOD impacts are two root causes that result in premature failure of these components. One way to mitigate the FOD related f...

  7. CIVIL LIABILITY FOR DAMAGE CAUSED TO BIOLOGICAL DIVERSITY

    OpenAIRE

    Левандовскі, К. М.

    2016-01-01

    For the passed half a century active development of biotechnologies changed the relation of the person to natural resources, in particular to flora and fauna. The modern methods of molecular biology made ‘simulated evolutionary jump’, having pushed aside traditional methods of selection and natural selection on a background. Nevertheless, so precipitant distribution of the alive changed organisms (ACO) within the planet as uniform ecosystem, forced the international community to develop the u...

  8. Effect of Oxidative Damage Due to Excessive Protein Ingestion on Pancreas Function in Mice

    Directory of Open Access Journals (Sweden)

    Huiyong Xu

    2010-11-01

    Full Text Available The present study was undertaken to evaluate the effect of oxidative damage due to excessive protein diet on pancreas function in mice. For this purpose, thirty male (C57BL/6J mice were randomly divided into three groups and fed on different diets as follows: group 1 was fed on a normal diet, group 2 was fed on an excessive protein diet and group 3 was fed on an excessive protein diet supplemented with 0.06 g/kg cysteamine. Each group was fed for 2 weeks, and then pancreas samples were collected to examine oxidative and antioxidant parameters and pancreas function. The results showed that ingestion of an excessive protein diet markedly increased contents of malondialdehyde (MDA and decreased T-AOC and activities of antioxidants SOD and GSH-Px, compared with a normal diet (P < 0.05. Pancreas weight and concentration of protein, DNA and RNA were significantly higher (P < 0.05, digestive enzyme activities were significantly lower and levels of somatostatin and insulin were higher in mice fed with an excessive protein diet than those fed with a normal protein diet. In the group fed with excessive protein diet supplemented with cysteamine, oxidative stress was mitigated and pancreas function was improved. These data demonstrate that excessive protein ingestion could increase oxidative damage of free radicals on pancreas function through destroying the balance of oxidants and antioxidants.

  9. Damage in Monolithic Thin-Film Photovoltaic Modules Due to Partial Shade

    Energy Technology Data Exchange (ETDEWEB)

    Silverman, Timothy J.; Mansfield, Lorelle; Repins, Ingrid; Kurtz, Sarah

    2016-09-01

    The typical configuration of monolithic thin-film photovoltaic modules makes it possible for partial shade to place one or more cells in such a module in reverse bias. Reverse bias operation leads to high voltage, current density, and power density conditions, which can act as driving forces for failure. We showed that a brief outdoor shadow event can cause a 7% permanent loss in power. We applied an indoor partial shade durability test that moves beyond the standard hot spot endurance test by using more realistic mask and bias conditions and by carefully quantifying the permanent change in performance due to the stress. With the addition of a pass criterion based on change in maximum power, this procedure will soon be proposed as a part of the module-type qualification test. All six commercial copper indium gallium diselenide and cadmium telluride modules we tested experienced permanent damage due to the indoor partial shade test, ranging from 4% to 14% loss in maximum power. We conclude by summarizing ways to mitigate partial shade stress at the cell, module, and system levels.

  10. A Comparison Between the Irradiation Damage Response of Spinel and Zirconia Due to Xe Ion Bombardment

    International Nuclear Information System (INIS)

    The mechanical properties of Xe-implanted spinel and cubic zirconia surfaces, as determined by nano-indentation measurements, are distinct and the differences can be related to their microstructures. Upon Xe(2+) ion irradiation at cryogenic temperature (120K), the Young's modulus of irradiated spinel increases slightly (a few percent) then falls dramatically until the modulus is only about 3/4 the unirradiated value. The maximum modulus occurs concurrent with the formation of a metastable crystalline phase of spinel. The subsequent elastic softening at higher Xe(2+) doses is an indication of the onset of amorphization of the spinel. Xe-implanted zirconia surfaces behaves differently, in all cases showing almost no change in elastic modulus with increasing Xe(2+) ion dose. This is consistent with microstructural observations of Xe-implanted zirconia crystals which, unlike spinel, show no change in crystal structure with increasing ion dose. The defected layer in zirconia due to ion damage simply thickens with increasing Xe(2+) dose. This thickening may be a consequence of compressive stresses that form in the ion- implanted surface region. The hardness of both spinel and zirconia increases slightly for low Xe(2+) ion doses. At higher doses, zirconia shows little change in hardness, while the hardness of the implanted spinel falls by more than a factor of two. The initial increase in hardness of both spinel and zirconia is probably due to point defect accumulation and the precipitation of small interstitial clusters, while the drop in hardness of spinel at high Xe(2+) ion doses is due to the formation of an amorphous phase

  11. Bacterial Genotoxins: Merging the DNA Damage Response into Infection Biology

    Directory of Open Access Journals (Sweden)

    Francesca Grasso

    2015-08-01

    Full Text Available Bacterial genotoxins are unique among bacterial toxins as their molecular target is DNA. The consequence of intoxication or infection is induction of DNA breaks that, if not properly repaired, results in irreversible cell cycle arrest (senescence or death of the target cells. At present, only three bacterial genotoxins have been identified. Two are protein toxins: the cytolethal distending toxin (CDT family produced by a number of Gram-negative bacteria and the typhoid toxin produced by Salmonella enterica serovar Typhi. The third member, colibactin, is a peptide-polyketide genotoxin, produced by strains belonging to the phylogenetic group B2 of Escherichia coli. This review will present the cellular effects of acute and chronic intoxication or infection with the genotoxins-producing bacteria. The carcinogenic properties and the role of these effectors in the context of the host-microbe interaction will be discussed. We will further highlight the open questions that remain to be solved regarding the biology of this unusual family of bacterial toxins.

  12. Evidence for DNA Damage as a Biological Link Between Diabetes and Cancer

    Institute of Scientific and Technical Information of China (English)

    Shao Chin Lee; Juliana CN Chan

    2015-01-01

    Objective:This review examines the evidence that:Diabetes is a state of DNA damage;pathophysiological factors in diabetes can cause DNA damage;DNA damage can cause mutations;and DNA mutation is linked to carcinogenesis.Data Sources:We retrieved information from the PubMed database up to January,2014,using various search terms and their combinations including DNA damage,diabetes,cancer,high glucose,hyperglycemia,free fatty acids,palmitic acid,advanced glycation end products,mutation and carcinogenesis.Study Selection:We included data from peer-reviewed journals and a textbook printed in English on relationships between DNA damage and diabetes as well as pathophysiological factors in diabetes.Publications on relationships among DNA damage,mutagenesis,and carcinogenesis,were also reviewed.We organized this information into a conceptual framework to explain the possible causal relationship between DNA damage and carcinogenesis in diabetes.Results:There are a large amount of data supporting the view that DNA mutation is a typical feature in carcinogenesis.Patients with type 2 diabetes have increased production of reactive oxygen species,reduced levels of antioxidant capacity,and increased levels of DNA damage.The pathophysiological factors and metabolic milieu in diabetes can cause DNA damage such as DNA strand break and base modification (i.e.,oxidation).Emerging experimental data suggest that signal pathways (i.e.,Akt/tuberin) link diabetes to DNA damage.This collective evidence indicates that diabetes is a pathophysiological state of oxidative stress and DNA damage which can lead to various types of mutation to cause aberration in cells and thereby increased cancer risk.Conclusions:This review highlights the interrelationships amongst diabetes,DNA damage,DNA mutation and carcinogenesis,which suggests that DNA damage can be a biological link between diabetes and cancer.

  13. Integrity management of Brazil-Bolivia gas pipeline to reduce risks due third party damage

    Energy Technology Data Exchange (ETDEWEB)

    Vasconcellos, Carlos Renato Aragonez de; Monte, Oswaldo [PETROBRAS, Rio de Janeiro, RJ (Brazil); Colen, Eustaquio; Cunha, Roberto de Souza; Oliveira, Hudson Regis de [Transportadora Brasileira Gasoduto Bolivia-Brasil, S.A., Rio de Janeiro, RJ (Brazil); Lima, Rogerio de Souza [RSL Consultoria Geoprojetos (Brazil); Schultz Neto, Walter [Milton Braga Assessoria Tecnica (Brazil)

    2005-07-01

    The Bolivia-Brazil Natural Gas Pipeline has 2.600 kilometers from Rio Grande City in Bolivia to Canoas City, in the south of Brazil. The right-of-way crosses a lot of types of topography and areas subjected to various kinds of anthropological actions, like areas in class locations 3, locals under agricultural activities, forests and minerals explorations, and near constructions of highway and railway, industrial constructions, new pipelines in the same right-of -way, channels, dams, that requires special projects to avoid that the gas pipeline could be subject to strengths that were not consider in the original design. The aim of this paper is to present the jobs developed by TBG during seven years of gas pipeline operations, as public awareness program, procedures to design, construct and inspect specials constructions along and near the right-of -way, control of mineral and forest explorations, monitoring and controlling of excavations on the right-of-way to install new pipelines and optical cables, to reduce risks of gas pipeline damage due third party, as a component of TBG' Managing Integrity Gas Pipeline Program. (author)

  14. Laser induced damage of fused silica polished optics due to a droplet forming organic contaminant

    Energy Technology Data Exchange (ETDEWEB)

    Bien-Aime, Karell; Neauport, Jerome; Tovena-Pecault, Isabelle; Fargin, Evelyne; Labrugere, Christine; Belin, Colette; Couzi, Michel

    2009-04-20

    We report on the effect of organic molecular contamination on single shot laser induced damage density at the wavelength of 351 nm, with a 3 ns pulse length. Specific contamination experiments were made with dioctylphthalate (DOP) in liquid or gaseous phase, on the surface of fused silica polished samples, bare or solgel coated. Systematic laser induced damage was observed only in the case of liquid phase contamination. Different chemical and morphological characterization methods were used to identify and understand the damage process. We demonstrate that the contaminant morphology, rather than its physicochemical nature, can be responsible for the decrease of laser induced damage threshold of optics.

  15. Laser induced damage of fused silica polished optics due to a droplet forming organic contaminant.

    Science.gov (United States)

    Bien-Aimé, Karell; Néauport, Jérome; Tovena-Pecault, Isabelle; Fargin, Evelyne; Labrugère, Christine; Belin, Colette; Couzi, Michel

    2009-04-20

    We report on the effect of organic molecular contamination on single shot laser induced damage density at the wavelength of 351 nm, with a 3 ns pulse length. Specific contamination experiments were made with dioctylphthalate (DOP) in liquid or gaseous phase, on the surface of fused silica polished samples, bare or solgel coated. Systematic laser induced damage was observed only in the case of liquid phase contamination. Different chemical and morphological characterization methods were used to identify and understand the damage process. We demonstrate that the contaminant morphology, rather than its physicochemical nature, can be responsible for the decrease of laser induced damage threshold of optics. PMID:19381171

  16. Displacement damage effects due to neutron and proton irradiations on CMOS image sensors manufactured in deep submicron technology

    OpenAIRE

    Virmontois, Cédric; Goiffon, Vincent; Magnan, Pierre; Girard, Sylvain; Inguimbert, Christophe; Petit, Sophie; Rolland, Guy; Saint-Pé, Olivier

    2010-01-01

    Displacement damage effects due to proton and neutron irradiations of CMOS image sensors dedicated to imaging are presented through the analysis of the dark current behavior in pixel arrays and isolated photodiodes. The mean dark current increase and the dark current nonuniformity are investigated. Dark current histogram observations are compared to damage energy distributions based on GEANT 4 calculations. We also discuss, through annealing analysis, which defects could be responsible for th...

  17. Damage-free vibrational spectroscopy of biological materials in the electron microscope

    Science.gov (United States)

    Rez, Peter; Aoki, Toshihiro; March, Katia; Gur, Dvir; Krivanek, Ondrej L.; Dellby, Niklas; Lovejoy, Tracy C.; Wolf, Sharon G.; Cohen, Hagai

    2016-03-01

    Vibrational spectroscopy in the electron microscope would be transformative in the study of biological samples, provided that radiation damage could be prevented. However, electron beams typically create high-energy excitations that severely accelerate sample degradation. Here this major difficulty is overcome using an `aloof' electron beam, positioned tens of nanometres away from the sample: high-energy excitations are suppressed, while vibrational modes of energies guanine crystals in their native state, resolving their characteristic C-H, N-H and C=O vibrational signatures with no observable radiation damage. The technique opens up the possibility of non-damaging compositional analyses of organic functional groups, including non-crystalline biological materials, at a spatial resolution of ~10 nm, simultaneously combined with imaging in the electron microscope.

  18. Damages of Biological Components in Bacteria and Bacteriophages Exposed to Atmospheric Non-thermal Plasma

    Science.gov (United States)

    Mizuno, Akira; Yasuda, Hachiro

    Mechanism of inactivation of bio-particles exposed to dielectric barrier discharge, DBD, has been studied using E. coli and bacteriophages. States of different biological components were monitored during the course of inactivation. Analysis of green fluorescent protein, GFP, introduced into E.coli cells proved that Non-thermal Plasma, NTP causes a prominent protein damages without cutting peptide bonds. We have developed a biological assay which evaluates in vitro DNA damage of the bacteriophages. Bacteriophage λ having double stranded DNA was exposed to DBD, then DNA was purified and subjected to in vitro DNA packaging reactions. The re-packaged phages consist of the DNA from discharged phages and brand-new coat proteins. Survival curves of the re-packaged phages showed extremely large D value (D = 25 s) compared to the previous D value (D = 3 s) from the discharged phages. The results indicate that DNA damage hardly contributed to the inactivation, and the damage in coat proteins is responsible for inactivation of the phages. M13 phages having single stranded DNA were also examined with the same manner. In this case, damage to DNA was as severe as that of the coat proteins.

  19. Numerical simulation of damage in high arch dam due to earthquake

    Institute of Scientific and Technical Information of China (English)

    Hong ZHONG; Gao LIN; Hongjun LI

    2009-01-01

    Based on the assumption that concrete is macroscopic homogeneous, the cracking evolution process and damage mode of high arch dams are studied in consideration of the heterogeneity of concrete in mesos-cale. The bilinear damage evolution model and the damage evolution model expressed in power function with descending section are adopted to combine with the Mohr-Coulomb criterion with tension cut-off to investigate the crack development and fracture mode of high arch dams under the action of an earthquake. The analysis result of a high arch dam in China under design shows that cracks that take place in concrete are caused by excessive tensile stress. The cracks initiate at the middle of the dam top and distribute at the upper half of the dam while the rest of the parts remain intact. This conclusion agrees with the model test result.

  20. Systems Biology of Saccharomyces cerevisiae Physiology and its DNA Damage Response

    DEFF Research Database (Denmark)

    Fazio, Alessandro

    . We have identified 268 growth rate dependent genes. These genes were used to identify key areas of the metabolism around which expression changes were significantly associated and we found nucleotide synthesis and ATP producing and consuming reactions. Moreover, by scoring the significance of overlap...... set of growth dependent genes by using a multi-factorial experimental design. Moreover, new insights into the metabolic response and transcriptional regulation of these genes have been provided by using systems biology tools (Chapter 3). One of the prerequisite of systems biology should...... used in the field of systems biology during the last decade. This thesis investigates S. cerevisiae growth physiology and DNA damage response by using a systems biology approach. Elucidation of the relationship between growth rate and gene expression is important to understand the mechanisms regulating...

  1. Protective effects of oleum curcumae wenchowensis on skin damage due to UVB

    International Nuclear Information System (INIS)

    Objective: To study the protective effects of oleum curcumae wenchowensis on skin damage exposed to UVB and its mechanism, and to provide the experimental basis for the protection of skin damage exposed to UVB. Methods: The skin of guinea pigs was exposed to UVB (28.38 J/cm2 · 30 d) to establish the oxidative damage model. The skin erythema and the rough were observed during the experiment; the thickness of epiderm and the number of fibroblast were observed under light microscope after the experiment. The activities of GSH-Px, SOD, CAT and T-AOC and the contain of MDA in the supernate of skin homogenate were detected with biochemical methods. Results: The epiderm in UVB exposure group and blank group thickened, but that in protective group weren't observed; the number of fibroblast in UVB exposure group and blank group decreased, while that in protective group increased, but that in control group didn't. The content of MDA in the supemate of skin homogenate in UVB exposure group and blank group increased, but that in protective group deceased, and the activities of GSH-Px, SOD, CAT and T-AOC in UVB exposure group and blank group decreased, but those in protective group increased, and control group had no change. Conclusions: Oleum curcumae wenchowensis has the protective effects on skin damage exposed to UVB, which may be mediated by increasing the contain of antioxidases and eliminating the flee radical. (authors)

  2. Detection of Damage due to Earthquake Using Mid-resolution Remotely Sensed Imageries

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-feng

    2007-01-01

    @@ How to mitigate the loss of human being's life and properties is extremely important.Truly improvement of building structure is significant,but when a big earthquake occurs,disaster is unavoidable,so emergency response immediately after an earthquake plays a vital role.naditional methods are time-consuming and laborious since almost everything is damaged after a big earthquake.

  3. Adverse effects of the antimalaria drug, mefloquine: due to primary liver damage with secondary thyroid involvement?

    Directory of Open Access Journals (Sweden)

    Herxheimer Andrew

    2002-03-01

    Full Text Available Abstract Background Mefloquine is a clinically important antimalaria drug, which is often not well tolerated. We critically reviewed 516 published case reports of mefloquine adverse effects, to clarify the phenomenology of the harms associated with mefloquine, and to make recommendations for safer prescribing. Presentation We postulate that many of the adverse effects of mefloquine are a post-hepatic syndrome caused by primary liver damage. In some users we believe that symptomatic thyroid disturbance occurs, either independently or as a secondary consequence of the hepatocellular injury. The mefloquine syndrome presents in a variety of ways including headache, gastrointestinal disturbances, nervousness, fatigue, disorders of sleep, mood, memory and concentration, and occasionally frank psychosis. Previous liver or thyroid disease, and concurrent insults to the liver (such as from alcohol, dehydration, an oral contraceptive pill, recreational drugs, and other liver-damaging drugs may be related to the development of severe or prolonged adverse reactions to mefloquine. Implications We believe that people with active liver or thyroid disease should not take mefloquine, whereas those with fully resolved neuropsychiatric illness may do so safely. Mefloquine users should avoid alcohol, recreational drugs, hormonal contraception and co-medications known to cause liver damage or thyroid damage. With these caveats, we believe that mefloquine may be safely prescribed in pregnancy, and also to occupational groups who carry out safety-critical tasks. Testing Mefloquine's adverse effects need to be investigated through a multicentre cohort study, with small controlled studies testing specific elements of the hypothesis.

  4. Dose-related effects of dexamethasone on liver damage due to bile duct ligation in rats

    Institute of Scientific and Technical Information of China (English)

    Halil Eken; Hayrettin Ozturk; Hulya Ozturk; Huseyin Buyukbayram

    2006-01-01

    AIM: To evaluate the effects of dexamethasone on liver damage in rats with bile duct ligation. METHODS: A total of 40 male Sprague-Dawley rats,weighing 165-205 g, were used in this study. Group 1 (sham-control, n = 10) rats underwent laparotomy alone and the bile duct was just dissected from the surrounding tissue. Group 2 rats (untreated, n = 10)were subjected to bile duct ligation (BDL) and no drug was applied. Group 3 rats (low-dose dexa, n = 10)received a daily dose of dexamethasone by orogastric tube for 14 d after BDL. Group 4 rats (high-dose dexa,n = 10) received a daily dose of dexamethasone by orogastric tube for 14 d after BDL. At the end of the twoweek period, biochemical and histological evaluations were processed.RESULTS: The mean serum bilirubin and liver enzyme levels significantly decreased, and superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSHPx) values were significantly increased in low-dose dexa and high-dose dexa groups when compared to the untreated group. The histopathological score was significantly less in the low-dose and high-dose dexa groups compared to the untreated rats. In the low-dose dexa group, moderate liver damage was seen, while mild liver damage was observed in the high-dose dexa group.CONCLUSION: Corticosteroids reduced liver damage produced by bile duct obstruction. However, the histopathological score was not significantly lower in the high-dose corticosteroid group as compared to the lowdose group. Thus, low-dose corticosteroid provides a significant reduction of liver damage without increased side effects, while high dose is associated not with lower fibrosis but with increased side effects.

  5. Damage estimation of subterranean building constructions due to groundwater inundation – the GIS-based model approach GRUWAD

    Directory of Open Access Journals (Sweden)

    R. Schinke

    2012-09-01

    Full Text Available The analysis and management of flood risk commonly focuses on surface water floods, because these types are often associated with high economic losses due to damage to buildings and settlements. The rising groundwater as a secondary effect of these floods induces additional damage, particularly in the basements of buildings. Mostly, these losses remain underestimated, because they are difficult to assess, especially for the entire building stock of flood-prone urban areas. For this purpose an appropriate methodology has been developed and lead to a groundwater damage simulation model named GRUWAD. The overall methodology combines various engineering and geoinformatic methods to calculate major damage processes by high groundwater levels. It considers a classification of buildings by building types, synthetic depth-damage functions for groundwater inundation as well as the results of a groundwater-flow model. The modular structure of this procedure can be adapted in the level of detail. Hence, the model allows damage calculations from the local to the regional scale. Among others it can be used to prepare risk maps, for ex-ante analysis of future risks, and to simulate the effects of mitigation measures. Therefore, the model is a multifarious tool for determining urban resilience with respect to high groundwater levels.

  6. Effects of carotenoids on damage of biological lipids induced by gamma irradiation

    Science.gov (United States)

    Saito, Takeshi; Fujii, Noriko

    2014-05-01

    Carotenoids are considered to be involved in the radioresistant mechanisms of radioresistant bacteria. In these bacterial cells, carotenoids are present in biological lipids, and therefore may be related to the radiation-induced damage of lipids. However, only limited data are available for the role of carotenoids in such damage. In this study, we irradiated an α-linolenic acid-benzene solution with gamma rays and analyzed the resulting oxidative degradation and peroxidation damage in the presence or absence of two typical carotenoids: β-carotene and astaxanthin. The analyses revealed that oxidative degradation and peroxidation of α-linolenic acid, as evaluated by the amount of malondialdehyde and conjugated diene formed, respectively, increased in a dose-dependent manner. Moreover, 8.5×10-3 M β-carotene inhibited gamma radiation-induced oxidative degradation of α-linolenic acid, whereas 5.0×10-5 and 5.0×10-6 M β-carotene, and 5.0×10-7 and 5.0×10-8 M astaxanthin promoted degradation. In contrast, neither β-carotene nor astaxanthin affected peroxidation of α-linolenic acid. These results suggest that an optimum concentration of carotenoids in radioresistant bacteria protects biological lipid structures from radiation-induced damage.

  7. Damage reconstruction due to impact of high-energetic particles on Malaysia Airlines flight MH17 (U)

    OpenAIRE

    2015-01-01

    The Dutch Safety Board (DSB) investigates the crash of Malaysia Airlines flight MH17 which occurred on Thursday July 17, 2014 in the Donetsk region (Ukraine). The DSB wants to provide a clear picture of the cause of the crash. A possible cause is fatal damage to the aircraft due to detonation of the warhead of a guided weapon. The DSB concluded the following in their initial report on the crash of flight MH17: “the damage to the forward section of the airplane seems to indicate that the airpl...

  8. Anisotropic damage model on the effects of damage process due to shearing stress in concrete - doi: 10.4025/actascitechnol.v35i2.13332

    Directory of Open Access Journals (Sweden)

    José Julio de Cerqueira Pituba

    2013-04-01

    Full Text Available This study deals with the proposal of damage variables related to structural behavior of the concrete subjected to shear stress. It is also addressed the laws of evolution and their incorporation into the formulation of a constitutive model for the concrete. Originally, this model considers the anisotropy and bimodularity induced by damage. Initially, the formulation of the damage model is briefly described. The material is assumed to behave as an elastic isotropic medium that start to present anisotropy and bimodular response (distinct elastic responses for prevailing states of tension or compression. Afterwards, we discussed some proposals of damage variables related to the structural behavior of the concrete when subjected to shear stress and their respective laws of evolution. The chosen proposal is then incorporated to the original model and implemented in a finite element code to perform plane analysis. Finally, the numerical responses of the model are compared with the experimental of reinforced concrete beams with different reinforcement rates. The results are presented and discussed aiming to verify the improvements presented by the new version of the model and to show the contribution of the energy dissipation due to shear in the cracked concrete behavior for the analyzed examples.  

  9. Differences in cracking resistance of asphalt mixtures due to ageing and moisture damage

    OpenAIRE

    López Montero, Teresa; Miró Recasens, José Rodrigo

    2016-01-01

    The ageing phenomenon and moisture damage become key factors to evaluate mixture cracking resistance. In this paper, the effect of ageing and water on cracking resistance and fatigue behavior in a bituminous mixture is studied. Specimens were tested by a direct tensile test (Fénix test) to obtain fracture energy values whereas variation of complex modulus and dissipated energy density was obtained by a strain sweep fatigue test (EBADE test). Results show a significant reduction in cracking re...

  10. Optimal Size for Maximal Energy Efficiency in Information Processing of Biological Systems Due to Bistability

    CERN Document Server

    Zhang, Chi; Wang, Long-Fei; Yue, Yuan; Yu, Lian-Chun

    2015-01-01

    Energy efficiency is closely related to the evolution of biological systems and is important to their information processing. In this paper, we calculated the excitation probability of a simple model of a bistable biological unit in response to pulsatile inputs, and its spontaneous excitation rate due to noise perturbation. Then we analytically calculated the mutual information, energy cost, and energy efficiency of an array of these bistable units. We found that the optimal number of units could maximize this array's energy efficiency in encoding pulse inputs, which depends on the fixed energy cost. We conclude that demand for energy efficiency in biological systems may strongly influence the size of these systems under the pressure of natural selection.

  11. Comparison of Model Calculations of Biological Damage from Exposure to Heavy Ions with Measurements

    Science.gov (United States)

    Kim, Myung-Hee Y.; Hada, Megumi; Cucinotta, Francis A.; Wu, Honglu

    2014-01-01

    The space environment consists of a varying field of radiation particles including high-energy ions, with spacecraft shielding material providing the major protection to astronauts from harmful exposure. Unlike low-LET gamma or X rays, the presence of shielding does not always reduce the radiation risks for energetic charged-particle exposure. Dose delivered by the charged particle increases sharply at the Bragg peak. However, the Bragg curve does not necessarily represent the biological damage along the particle path since biological effects are influenced by the track structures of both primary and secondary particles. Therefore, the ''biological Bragg curve'' is dependent on the energy and the type of the primary particle and may vary for different biological end points. Measurements of the induction of micronuclei (MN) have made across the Bragg curve in human fibroblasts exposed to energetic silicon and iron ions in vitro at two different energies, 300 MeV/nucleon and 1 GeV/nucleon. Although the data did not reveal an increased yield of MN at the location of the Bragg peak, the increased inhibition of cell progression, which is related to cell death, was found at the Bragg peak location. These results are compared to the calculations of biological damage using a stochastic Monte-Carlo track structure model, Galactic Cosmic Ray Event-based Risk Model (GERM) code (Cucinotta, et al., 2011). The GERM code estimates the basic physical properties along the passage of heavy ions in tissue and shielding materials, by which the experimental set-up can be interpreted. The code can also be used to describe the biophysical events of interest in radiobiology, cancer therapy, and space exploration. The calculation has shown that the severely damaged cells at the Bragg peak are more likely to go through reproductive death, the so called "overkill".

  12. Biological significance of the focus on DNA damage checkpoint factors remained after irradiation of ionizing radiation

    International Nuclear Information System (INIS)

    This paper reviews recent reports on the focus formation and participation to checkpoint of (such phosphorylated (P-d) as below) ATM and H2AX, MDC1, 53BP1 and NBS1, and discusses their role in DNA damage checkpoint induction mainly around authors' studies. When the cell is irradiated by ionizing radiation, the subtype histone like H2AX is P-d and the formed focus', seen in the nucleus on immuno-fluorographic observation, represents the P-d H2AX at the damaged site of DNA. The role of P-d ATM (the product of causative gene of ataxia-telangiectasia mutation, a protein kinase) has been first shown by laser beam irradiation. Described are discussions on the roles and functions after irradiation in focus formation and DNA damage checkpoint of P-d H2AX (a specific histone product by the radiation like γ-ray as above), P-d ATM, MDC1 (a mediator of DNA damage check point protein 1), 53BP1, (a p53 binding protein) and NBS1 (the product of the causative gene of Nijmegen Breakage Syndrome). Authors have come to point out the remained focal size increase as implications of the efficient repair of damaged DNA, and the second cycled p53 accumulation, of tumor suppression. Thus evaluation of biological significance of these aspects, scarcely noted hitherto, is concluded important. (S.I.)

  13. Computational Hydrocode Study of Target Damage due to Fragment-Blast Impact

    Energy Technology Data Exchange (ETDEWEB)

    Hatch-Aguilar, T; Najjar, F; Szymanski, E

    2011-03-24

    A target's terminal ballistic effects involving explosively generated fragments, along with the original blast, are of critical importance for many different security and safety related applications. Personnel safety and protective building design are but a few of the practical disciplines that can gain from improved understanding combined loading effects. Traditionally, any engineering level analysis or design effort involving explosions would divide the target damage analysis into two correspondingly critical areas: blast wave and fragment related impact effects. The hypothesis of this paper lies in the supposition that a linear combination of a blast-fragment loading, coupled with an accurate target response description, can lead to a non-linear target damage effect. This non-linear target response could then stand as the basis of defining what a synergistic or combined frag-blast loading might actually look like. The table below, taken from Walters, et. al. categorizes some of the critical parameters driving any combined target damage effect and drives the evaluation of results. Based on table 1 it becomes clear that any combined frag-blast analysis would need to account for the target response matching similar ranges for the mechanics described above. Of interest are the critical times upon which a blast event or fragment impact loading occurs relative to the target's modal response. A blast, for the purposes of this paper is defined as the sudden release of chemical energy from a given material (henceforth referred to as an energetic material) onto its surrounding medium. During the coupling mechanism a discrete or discontinuous shockwave is generated. This shockwave travels outward from the source transferring energy and momentum to any surrounding objects including personnel and engineering structures. From an engineering perspective blast effects are typically characterized by way of physical characteristics such as Peak Pressure (PP), Time of

  14. A damage mechanics approach for quantifying stress changes due to brittle failure of porous rocks

    Science.gov (United States)

    Jacquey, Antoine B.; Cacace, Mauro; Blöcher, Guido; Milsch, Harald; Scheck-Wenderoth, Magdalena

    2016-04-01

    Natural fault zones or man-made injection or production of fluid impact the regional stress distribution in Earth's crust and can be responsible for localized stress discontinuities. Understanding the processes controlling fracturing of the porous rocks and mechanical behaviour of fault zones is therefore of interest for several applications including geothermal energy production. In this contribution, we will present a thermodynamically consistent visco-poroelastic damage model which can deal with the multi-scale and multi-physics nature of the physical processes controlling the deformation of porous rocks during and after brittle failure. Deformation of a porous medium is crucially influenced by the changes in the effective stress. Considering a strain-formulated yield cap and the compaction-dilation transition, three different regimes can be identified: quasi-elastic deformation, cataclastic compaction with microcracking (damage accumulation) and macroscopic brittle failure with dilation. The governing equations for deformation, damage accumulation/healing and fluid flow have been implemented in a fully-coupled finite-element-method based framework (MOOSE). The MOOSE framework provides a powerful and flexible platform to solve multiphysics problems implicitly and in a tightly coupled manner on unstructured meshes which is of interest for such non-linear context. To illustrate the model, simulation of a compaction experiment of a sandstone leading to shear failure will be presented which allows to quantify the stress drop accompanying the failure. Finally, we will demonstrate that this approach can also be used at the field scale to simulate hydraulic fracturing and assess the resulting changes in the stress field.

  15. Histopathological And Biological Studies On The Role Of Soybean And Broad Bean AgainstRadiation Induce Damage In Rat Kidney

    Directory of Open Access Journals (Sweden)

    Hanaa Fathy Waer, **Abdel El ­ Rahman Mohamed Attia

    2002-09-01

    Full Text Available Most of the physiological and histological activities in the animal body are disturbed after exposure to ionizing radiation. These disturbances are either due to direct harmful effect of radiation on the biological systems or to the indirect effect of free radicals formed in the body after irradiation. There is growing evidence that the type of food plays an important role in the prevention of chronic diseases. The biological disturbance due to ionizing radiation makes search for ways of protecting living organisms essential for controlling the radiation hazards. Much of the world population relies on legumes, as a stable food. Legumes can affectively protect cells and tissues against damage. Our present study was conducted to investigate the hazardous effects of single dose !"#$%#&f the possible protective effect of feeding beans (broad beans and soybeans against radiation exposure. Histopathological, and biological changes of kidney function in irradiated, and bean fed animals were carried out. Animals were weighted and daily food intake was determined. The result obtained revealed that soybean is an extremely rich source of protein and fat as compared to faba bean. Radiations cause a reduction in food intake and weight gain. It causes great changes in the kidney glomeruli and collecting tubules. The recovery of the cells depend on the type of feeding so, feeding soybean gives a significant radiation protection and decreases the extent of changes induced by radiation

  16. Radiation effects and damage formation in semiconductors due to high-energy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kamarou, A.

    2006-11-07

    The object of this thesis was the study of ion-beam induced damage formation and annealing in crystalline and conventionally predamaged Ge, GaAs, and InP. The samples were irradiated either at {approx}80 K or at room temperature with Kr, Xe, or Au ions with specific energy of about 0.3 MeV/u to 3 MeV/u. Thereafter the samples were studied by means of Rutherford backscattering spectroscopy and/or transmission electron microscopy.

  17. Physical Damages of Wood Fiber in Acacia Mangium due to Biopulping Treatment

    Directory of Open Access Journals (Sweden)

    Ridwan Yahya

    2016-05-01

    chrysosporium to Acacia mangium Willd can reduce lignin and improve holocellulose and cellulose content of the material. Fiber dimension recognized as other important factor for paper properties. The question is how the integrity and dimensions of the wood fiber that has been pretreated with the fungus. The objectives of present study were to know effect of pretreatment of P. chrysosporium to the integrity and dimensions of the fiber. The P. chrysosporium was cultured for 14 days in growth medium, and inoculated to wood chips 5% (w/v and incubated for 0, 15 and 30 days. The inoculated wood chips were chipped into 1 mm x 1 mm x 20 mm and macerated using franklin solution at 60 oC for 48 hours. Forty fibers from each incubated time were analized their physical damages using a light microscope at a 400 magnification. The inoculated fibers were measured theirs dimensions. The physical damage percentage of fibers pretreated using P. chrysosporium was 0%. Length and wall thickness of the pretreated fibers were can be categorized as middle class and thin fibers, respectively.

  18. Hardening due to dislocation loop damage in RPV model alloys: Role of Mn segregation

    Energy Technology Data Exchange (ETDEWEB)

    Terentyev, D., E-mail: dterenty@sckcen.be [SCK-CEN, Nuclear Materials Science Institute, Boeretang 200, B-2400 Mol (Belgium); He, X. [China Institute of Atomic Energy, P.O. Box: 275-51, 102413 Beijing (China); Bonny, G. [SCK-CEN, Nuclear Materials Science Institute, Boeretang 200, B-2400 Mol (Belgium); Bakaev, A. [SCK-CEN, Nuclear Materials Science Institute, Boeretang 200, B-2400 Mol (Belgium); Center for Molecular Modeling, Department of Physics and Astronomy, Ghent University, Technologiepark 903, 9052 Zwijnaarde (Belgium); Department of Experimental Nuclear Physics, Faculty of Physics and Mechanics, Institute of Physics, Nanotechnologies and Telecommunications, St. Petersburg State Polytechnical University, 29 Polytekhnicheskaya str., 195251 St. Petersburg (Russian Federation); Zhurkin, E. [Department of Experimental Nuclear Physics, Faculty of Physics and Mechanics, Institute of Physics, Nanotechnologies and Telecommunications, St. Petersburg State Polytechnical University, 29 Polytekhnicheskaya str., 195251 St. Petersburg (Russian Federation); Malerba, L. [SCK-CEN, Nuclear Materials Science Institute, Boeretang 200, B-2400 Mol (Belgium)

    2015-02-15

    The exact nature of the radiation defects causing hardening in reactor vessel pressure steels at high doses is not yet clearly determined. While generally it is attributed to solute-rich clusters (precipitates) and point defects clusters (matrix damage), recent fine-scale experiments and atomistic simulations suggest that solute rich clusters, mainly containing Mn, Ni and Cu, might be the result of the segregation of these elements to small dislocation loops (heterogeneous nucleation), so that the distinction between precipitates and matrix damage becomes blurred. Here, we perform an atomistic study to investigate the interaction of a{sub 0}/2〈1 1 1〉 dislocation loops with moving dislocations and specifically address the effect of solute segregation on the loop’s strength and interaction mechanism, focusing in particular on Mn, alone or with other crucial solute elements such as Cu and Ni. It is found that the enrichment of Mn in the core of dislocation loops causes significant increase of the unpinning stress, especially for small, invisible ones. At the same time, the solute segregation at the dislocation loops enhances their resistance against absorption by moving dislocations.

  19. Risk control and prevention of spinal cord damage due to surgery of thoracoabdominal aneurysms: medicolegal aspects.

    Science.gov (United States)

    de Mol, B; Hamerlijnck, R; Vermeulen, F E; de Geest, R

    1991-01-01

    Surgery of thoracoabdominal aneurysms is accompanied by many complications of which spinal cord damage is the most serious. Such a complication tends to be the subject of litigation and medicolegal assessment. This report presents a risk control concept focussed on the reduction of spinal cord damage after surgery for a thoracoabdominal aneurysm. This concept may provide a basis for a risk management program in major surgery. Apart from sparing the patient a serious complication, improvement of the quality of care and anticipation of a medicolegal assessment were considered valuable benefits of such an effort. It is described how the threat of litigation--also in Europe--may affect clinical practice. A definition of surgical failure is described related to the five elements of risk homeostasis: complexity, linkage, cascade, human factor and safety margins. Limitations of risk control in the surgery of thoracoabdominal aneurysms are described. Finally the role of perception of risks by patient and doctor as well as the importance of informed consent and adequate disclosure are described in respect of medical quality improvement and litigation.

  20. Protective Effect of Selected Medicinal Plants against Hydrogen Peroxide Induced Oxidative Damage on Biological Substrates

    OpenAIRE

    Pai Kotebagilu, Namratha; Reddy Palvai, Vanitha; Urooj, Asna

    2014-01-01

    Oxidative stress is developed due to susceptibility of biological substrates to oxidation by generation of free radicals. In degenerative diseases, oxidative stress level can be reduced by antioxidants which neutralize free radicals. Primary objective of this work was to screen four medicinal plants, namely, Andrographis paniculata, Costus speciosus, Canthium parviflorum, and Abrus precatorius, for their antioxidant property using two biological substrates—RBC and microsomes. The antioxidativ...

  1. Damage to agricultural yield due to farmland birds, present repelling techniques and its impacts : an insight from the Indian perspective

    OpenAIRE

    Kale, Manoj; Balfors, Berit; Mörtberg, Ulla; Bhattacharya, Prosun; Chakane, Sanjay

    2012-01-01

    In India, nearly 65% of the people are directly or indirectly dependent on agricultural sector for economic survival. The annual income of farmers is significantly influenced by the yield of the crops, which is continuously decreasing due to natural phenomena and poor technological advancement. However, the particular attention should be paid to the damage caused by birds. While the exact measure of the loss in yield associated with birds is unknown, farmers integrate a number of traditional ...

  2. Stress and Damage in Polymer Matrix Composite Materials Due to Material Degradation at High Temperatures

    Science.gov (United States)

    McManus, Hugh L.; Chamis, Christos C.

    1996-01-01

    This report describes analytical methods for calculating stresses and damage caused by degradation of the matrix constituent in polymer matrix composite materials. Laminate geometry, material properties, and matrix degradation states are specified as functions of position and time. Matrix shrinkage and property changes are modeled as functions of the degradation states. The model is incorporated into an existing composite mechanics computer code. Stresses, strains, and deformations at the laminate, ply, and micro levels are calculated, and from these calculations it is determined if there is failure of any kind. The rationale for the model (based on published experimental work) is presented, its integration into the laminate analysis code is outlined, and example results are given, with comparisons to existing material and structural data. The mechanisms behind the changes in properties and in surface cracking during long-term aging of polyimide matrix composites are clarified. High-temperature-material test methods are also evaluated.

  3. Recent Advances in Targeted, Self-Assembling Nanoparticles to Address Vascular Damage Due to Atherosclerosis.

    Science.gov (United States)

    Chung, Eun Ji; Tirrell, Matthew

    2015-11-18

    Self-assembling nanoparticles functionalized with targeting moieties have significant potential for atherosclerosis nanomedicine. While self-assembly allows the easy construction (and degradation) of nanoparticles with therapeutic or diagnostic functionality, or both, the targeting agent can direct them to a specific molecular marker within a given stage of the disease. Therefore, supramolecular nanoparticles have been investigated in the last decade as molecular imaging agents or explored as nanocarriers that can decrease the systemic toxicity of drugs by producing accumulation predominantly in specific tissues of interest. In this Progress Report, the pathogenesis of atherosclerosis and the damage caused to vascular tissue are described, as well as the current diagnostic and treatment options. An overview of targeted strategies using self-assembling nanoparticles is provided, including liposomes, high density lipoproteins, protein cages, micelles, proticles, and perfluorocarbon nanoparticles. Finally, an overview is given of current challenges, limitations, and future applications for personalized medicine in the context of atherosclerosis of self-assembling nanoparticles.

  4. Design retrofit to prevent damage due to heat transport pump operation under conditions of significant void

    International Nuclear Information System (INIS)

    The purpose of this paper is to provide a general review of certain key design areas which address the safety concerns of HT pump operation under conditions of significant void. To illustrate the challenges confronting designers and analysts, some of the highlights during the design of a protective system to prevent damage to HT piping and pump supports at Bruce NGS 'A' are outlined. The effects of this protective system on reactor safety are also discussed. HI pump operation under conditions of significant void offers a major challenge to designers and analysts to ensure that pump induced vibration and its effects on pump and piping are addressed. For an in-service station the search for a practical solution is often limited by existing. station equipment design and Layout. The diversity of design verification process requires a major commitment of engineering resources to ensure all. safety aspects meet the requirements of regulatory body. Work currently undertaken at Ontario Hydro Research Pump Test Complex on two-phase flow in pumps and piping may provide better prediction of vibration characteristics so that inherent conservativeness in fatigue Life prediction of HI system components can be reduced

  5. Complementing xeroderma pigmentosum fibroblasts restore biological activity to UV-damaged DNA

    International Nuclear Information System (INIS)

    UV survival curves of adenovirus 2 using fused complementing xeroderma pigmentosum fibroblast strains as virus hosts showed a component with an inactivation slope identical to that given by normal cells. This component was not observed when the fibroblasts were not fused or when fusions involved strains in the same complementing group. Extrapolation to zero dose indicated that three percent of the viral plaque-forming units had infected cells capable of normal repair; this suggested that three percent of the cells were complementing heterokaryons. Thus, heterokaryons formed from xeroderma pigmentosum fibroblasts belonging to different complementation groups are as capable of restoring biological activity to UV-damaged adenovirus 2 as are normal cells

  6. Estimation of the Past and Future Infrastructure Damage Due the Permafrost Evolution Processes

    Science.gov (United States)

    Sergeev, D. O.; Chesnokova, I. V.; Morozova, A. V.

    2015-12-01

    The geocryological processes such as thermokarst, frost heaving and fracturing, icing, thermal erosion are the source of immediate danger for the structures. The economic losses during the construction procedures in the permafrost area are linked also with the other geological processes that have the specific character in cold regions. These processes are swamping, desertification, deflation, flooding, mudflows and landslides. Linear transport structures are most vulnerable component of regional and national economy. Because the high length the transport structures have to cross the landscapes with different permafrost conditions that have the different reaction to climate change. The climate warming is favorable for thermokarst and the frost heaving is linked with climate cooling. In result the structure falls in the circumstances that are not predicted in the construction project. Local engineering problems of structure exploitation lead to global risks of sustainable development of regions. Authors developed the database of geocryological damage cases for the last twelve years at the Russian territory. Spatial data have the attributive table that was filled by the published information from various permafrost conference proceedings. The preliminary GIS-analysis of gathered data showed the widespread territorial distribution of the cases of negative consequences of geocryological processes activity. The information about maximum effect from geocryological processes was validated by detailed field investigation along the railways in Yamal and Transbaicalia Regions. Authors expect the expanding of database by similar data from other sectors of Arctic. It is important for analyzing the regional, time and industrial tendencies of geocryological risk evolution. Obtained information could be used in insurance procedures and in information systems of decisions support in different management levels. The investigation was completed with financial support by Russian

  7. DNA damage due to perfluorooctane sulfonate based on nano-gold embedded in nano-porous poly-pyrrole film

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Liping, E-mail: lipinglu@bjut.edu.cn; Xu, Laihui; Kang, Tianfang; Cheng, Shuiyuan

    2013-11-01

    DNA damage induced from perfluorooctane sulfonate (PFOS) was further developed on a nano-porous bionic interface. The interface was formed by assembling DNA on nano-gold particles which were embedded in a nano-porous overoxidized polypyrrole film (OPPy). Atomic force microscopy, scanning electron microscope and electrochemical investigations indicate that OPPy can be treated to form nano-pore structures. DNA damage due to PFOS was proved using electrochemistry and X-ray photoelectron spectroscopy (XPS) and was investigated by detecting differential pulse voltammetry (DPV) response of methylene blue (MB) which was used as electro-active indicator in the system. The current of MB attenuates obviously after incubation of DNA in PFOS. Moreover, electrochemical impedance spectroscopy (EIS) demonstrates that PFOS weakens DNA charge transport. The tentative binding ratio of PFOS: DNA base pair was obtained by analyzing XPS data of this system.

  8. Comment on a mathematical model for estimating biological damage caused by radiation. Whack-A-Mole model

    International Nuclear Information System (INIS)

    We propose a mathematical model, Whack-A-Mole (WAM) model which can estimate the biological effect caused by radiation. The WAM model assumes that the basic element is a cell and the number of cells increases or decreases due to response to stimulus, damage and recovery, cause by radiation and so on. WAM takes into account dose rate as an important physical quantity, which marks a fundamental difference from target theory or LQ model. WAM model reproduces various experimental data of mutation frequency induced by radiation, for example, mega-mouse project. Furthermore, we can predict unknown experimental results. From WAM model, it is learnt that the mutation frequency caused by radiation is not proportional to dose but also have saturation value. There is some possibility that the WAM model will drastically change risk estimation of radiation as it brings us different results from those of target theory or LQ model. (author)

  9. Comparison of Model Calculations of Biological Damage from Exposure to Heavy Ions with Measurements

    Science.gov (United States)

    Kim, Myung-Hee Y.; Wu, Honglu; Hada, Megumi; Cucinotta, Francis

    The space environment consists of a varying field of radiation particles including high-energy ions, with spacecraft shielding material providing the major protection to astronauts from harmful exposure. Unlike low-LET g or X rays, the presence of shielding does not always reduce the radiation risks for energetic charged-particle exposure. Dose delivered by the charged particle increases sharply at the Bragg peak. However, the Bragg curve does not necessarily represent the biological damage along the particle path since biological effects are influenced by the track structures of both primary and secondary particles. Therefore, the ‘‘biological Bragg curve’’ is dependent on the energy and the type of the primary particle and may vary for different biological end points. Measurements of the induction of micronuclei (MN) have made across the Bragg curve in human fibroblasts exposed to energetic silicon and iron ions in vitro at two different energies, 300 MeV/nucleon and 1 GeV/nucleon. Although the data did not reveal an increased yield of MN at the location of the Bragg peak, the increased inhibition of cell progression, which is related to cell death, was found at the Bragg peak location. These results are compared to the calculations of biological damage using a stochastic Monte-Carlo track structure model, Galactic Cosmic Ray Event-based Risk Model (GERM) code (Cucinotta et al., 2011). The GERM code estimates the basic physical properties along the passage of heavy ions in tissue and shielding materials, by which the experimental set-up can be interpreted. The code can also be used to describe the biophysical events of interest in radiobiology, cancer therapy, and space exploration. The calculation has shown that the severely damaged cells at the Bragg peak are more likely to go through reproductive death, the so called “overkill”. F. A. Cucinotta, I. Plante, A. L. Ponomarev, and M. Y. Kim, Nuclear Interactions in Heavy Ion Transport and Event

  10. Bulk damage and absorption in fused silica due to high-power laser applications

    Science.gov (United States)

    Nürnberg, F.; Kühn, B.; Langner, A.; Altwein, M.; Schötz, G.; Takke, R.; Thomas, S.; Vydra, J.

    2015-11-01

    Laser fusion projects are heading for IR optics with high broadband transmission, high shock and temperature resistance, long laser durability, and best purity. For this application, fused silica is an excellent choice. The energy density threshold on IR laser optics is mainly influenced by the purity and homogeneity of the fused silica. The absorption behavior regarding the hydroxyl content was studied for various synthetic fused silica grades. The main absorption influenced by OH vibrational excitation leads to different IR attenuations for OH-rich and low-OH fused silica. Industrial laser systems aim for the maximum energy extraction possible. Heraeus Quarzglas developed an Yb-doped fused silica fiber to support this growing market. But the performance of laser welding and cutting systems is fundamentally limited by beam quality and stability of focus. Since absorption in the optical components of optical systems has a detrimental effect on the laser focus shift, the beam energy loss and the resulting heating has to be minimized both in the bulk materials and at the coated surfaces. In collaboration with a laser research institute, an optical finisher and end users, photo thermal absorption measurements on coated samples of different fused silica grades were performed to investigate the influence of basic material properties on the absorption level. High purity, synthetic fused silica is as well the material of choice for optical components designed for DUV applications (wavelength range 160 nm - 260 nm). For higher light intensities, e.g. provided by Excimer lasers, UV photons may generate defect centers that effect the optical properties during usage, resulting in an aging of the optical components (UV radiation damage). Powerful Excimer lasers require optical materials that can withstand photon energy close to the band gap and the high intensity of the short pulse length. The UV transmission loss is restricted to the DUV wavelength range below 300 nm and

  11. Biological Effects of Gamma-Ray Bursts: Critical distances for severe damage on the biota

    CERN Document Server

    Galante, D; Galante, Douglas; Horvath, Jorge Ernesto

    2005-01-01

    We present in this work a unified, quantitative synthesis of analytical and numerical calculations of the effects caused on an Earth-like planet by a Gamma-Ray Burst (GRB), considering atmospheric and biological implications. The main effects of the illumination by a GRB are classified in four distinct ones and analyzed separately, namely the direct gamma radiation transmission, UV flash, ozone layer depletion and cosmic rays. The effectiveness of each of these effects is compared and lethal distances for significant biological damage are given for each one. We find that the first three effects have potential to cause global environmental changes and biospheric damages, even if the source is located at great distances (perhaps up to ~ 100 kpc). Instead, cosmic rays would only be a serious threat for very close sources. As a concrete example of a recorded similar event, the effects of the giant flare from SGR1806-20 of Dec 27, 2004 could cause on the biosphere are addressed. In spite of not belonging to the so...

  12. A comparative study of bridge damage due to the Wenchuan,Northridge, Loma Prieta and San Fernando earthquakes

    Institute of Scientific and Technical Information of China (English)

    Wang Zhiqiang; George C. Lee

    2009-01-01

    A comparative study of selected bridge damage due to the Wenchuan, Northridge, Loma Prieta and San Fernando earthquakes is described in this paper. Typical ground motion effects considered include large ground fault displacement, liquefaction, landslide, and strong ground shaking. Issues related to falling spans, inadequate detailing for structural ductility and complex bridge configurations are discussed within the context of the recent seismic design codes of China and the US. A significant lesson learned from the Great Wenchuan earthquake, far beyond the opportunities to improve the seismic design provisions for bridges, is articulated.

  13. Contrast reduction in digital images due to x-ray induced damage to a TV camera's CCD image receptor

    International Nuclear Information System (INIS)

    The CCD image receptor in a monochrome TV camera was irradiated in the dark with a single-phase 80 kVp narrow beam carrying an additional 0.5 mm Al filter. It was found that the CCD responded to the x-rays with a transient signal which would reach a maximum value at about 70 mR per image frame. The signal's contrast would reach a maximum of about 7%, but was detectable at much lower exposure rates. Continuous irradiation of the CCD image receptor created a 'lesion' at the point of incidence that remained after the x-ray beam was switched off. This signal seemed to be due to permanent damage to the CCD and could be detected after a cumulative exposure of less than 20 R. It was shown that such damage could be created much more effectively if the TV camera was switched off rather than on and the maximum contrast was achieved with about 75 R and 220 R respectively. The maximum contrast achieved was about 8%. Further increase in the cumulative exposure of a particular location on the CCD image receptor was not investigated but it seemed reasonable that much higher contrast values could be reached if irradiation was continued. The latter damage described here was found to persist for at least several weeks and hence it will probably prevent any normal use of the TV camera in the future. (author)

  14. Honey bee (Apis mellifera) drones survive oxidative stress due to increased tolerance instead of avoidance or repair of oxidative damage.

    Science.gov (United States)

    Li-Byarlay, Hongmei; Huang, Ming Hua; Simone-Finstrom, Michael; Strand, Micheline K; Tarpy, David R; Rueppell, Olav

    2016-10-01

    Oxidative stress can lead to premature aging symptoms and cause acute mortality at higher doses in a range of organisms. Oxidative stress resistance and longevity are mechanistically and phenotypically linked; considerable variation in oxidative stress resistance exists among and within species and typically covaries with life expectancy. However, it is unclear whether stress-resistant, long-lived individuals avoid, repair, or tolerate molecular damage to survive longer than others. The honey bee (Apis mellifera L.) is an emerging model system that is well-suited to address this question. Furthermore, this species is the most economically important pollinator, whose health may be compromised by pesticide exposure, including oxidative stressors. Here, we develop a protocol for inducing oxidative stress in honey bee males (drones) via Paraquat injection. After injection, individuals from different colony sources were kept in common social conditions to monitor their survival compared to saline-injected controls. Oxidative stress was measured in susceptible and resistant individuals. Paraquat drastically reduced survival but individuals varied in their resistance to treatment within and among colony sources. Longer-lived individuals exhibited higher levels of lipid peroxidation than individuals dying early. In contrast, the level of protein carbonylation was not significantly different between the two groups. This first study of oxidative stress in male honey bees suggests that survival of an acute oxidative stressor is due to tolerance, not prevention or repair, of oxidative damage to lipids. It also demonstrates colony differences in oxidative stress resistance that might be useful for breeding stress-resistant honey bees.

  15. An assessment of the resolution limitation due to radiation-damage in X-ray diffraction microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Howells, M.R. [Advanced Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States)], E-mail: mrhowells@lbl.gov; Beetz, T. [Department of Physics, State University of New York, Stony Brook, NY 11794 (United States); Chapman, H.N. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 (United States); Cui, C. [Advanced Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Holton, J.M. [Advanced Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94158-2330 (United States); Jacobsen, C.J.; Kirz, J. [Advanced Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Department of Physics, State University of New York, Stony Brook, NY 11794 (United States); Lima, E. [Department of Physics, State University of New York, Stony Brook, NY 11794 (United States); Marchesini, S. [Advanced Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Miao, H.; Sayre, D. [Department of Physics, State University of New York, Stony Brook, NY 11794 (United States); Shapiro, D.A. [Advanced Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Spence, J.C.H. [Advanced Light Source, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Department of Physics and Astronomy, Arizona State University, Tempe, AZ 85287-1504 (United States); Starodub, D. [Department of Physics and Astronomy, Arizona State University, Tempe, AZ 85287-1504 (United States)

    2009-03-15

    X-ray diffraction microscopy (XDM) is a new form of X-ray imaging that is being practiced at several third-generation synchrotron-radiation X-ray facilities. Nine years have elapsed since the technique was first introduced and it has made rapid progress in demonstrating high-resolution three-dimensional imaging and promises few-nanometer resolution with much larger samples than can be imaged in the transmission electron microscope. Both life- and materials-science applications of XDM are intended, and it is expected that the principal limitation to resolution will be radiation damage for life science and the coherent power of available X-ray sources for material science. In this paper we address the question of the role of radiation damage. We use a statistical analysis based on the so-called 'dose fractionation theorem' of Hegerl and Hoppe to calculate the dose needed to make an image of a single life-science sample by XDM with a given resolution. We find that the needed dose scales with the inverse fourth power of the resolution and present experimental evidence to support this finding. To determine the maximum tolerable dose we have assembled a number of data taken from the literature plus some measurements of our own which cover ranges of resolution that are not well covered otherwise. The conclusion of this study is that, based on the natural contrast between protein and water and 'Rose-criterion' image quality, one should be able to image a frozen-hydrated biological sample using XDM at a resolution of about 10 nm.

  16. An assessment of the resolution limitation due to radiation-damage in X-ray diffraction microscopy

    International Nuclear Information System (INIS)

    X-ray diffraction microscopy (XDM) is a new form of X-ray imaging that is being practiced at several third-generation synchrotron-radiation X-ray facilities. Nine years have elapsed since the technique was first introduced and it has made rapid progress in demonstrating high-resolution three-dimensional imaging and promises few-nanometer resolution with much larger samples than can be imaged in the transmission electron microscope. Both life- and materials-science applications of XDM are intended, and it is expected that the principal limitation to resolution will be radiation damage for life science and the coherent power of available X-ray sources for material science. In this paper we address the question of the role of radiation damage. We use a statistical analysis based on the so-called 'dose fractionation theorem' of Hegerl and Hoppe to calculate the dose needed to make an image of a single life-science sample by XDM with a given resolution. We find that the needed dose scales with the inverse fourth power of the resolution and present experimental evidence to support this finding. To determine the maximum tolerable dose we have assembled a number of data taken from the literature plus some measurements of our own which cover ranges of resolution that are not well covered otherwise. The conclusion of this study is that, based on the natural contrast between protein and water and 'Rose-criterion' image quality, one should be able to image a frozen-hydrated biological sample using XDM at a resolution of about 10 nm.

  17. Test of radiation damage enhancement due to incorporation of BrUdR into DNA using chromatid aberrations

    International Nuclear Information System (INIS)

    Monte Carlo track structure calculations, leading to an estimation of the magnitude of enhancement of radiation damage due to the incorporation of the halogenated pyrimidine, bromodeoxyuridine (BrUdR) a thymine analog, into DNA have been made. The increase in the yield of double strand breaks for various degrees of substitution in one (monofilarly) or both strands (bifilarly) have been calculated. To test these calculations, quantitative selected radiation-induced aberrations have been obtained in Chinese hamster (V79) fibroblast chromosomes having various patterns of BrUdR substitution following irradiation with 250 kV X rays. Free ''breaks'' and achromatic lesions ''gaps'' show no appreciable sensitizations, but breaks involved in chromatid interchanges show significant enhancement though of lower magnitude than theoretical predictions

  18. Laser device for the protection of biological objects from the damaging action of ionizing radiation

    International Nuclear Information System (INIS)

    The search for ideal protective agents for use in radiotherapy or post-exposure treatment of victims of radiation accidents is one of the actual problems of radiation protection. Laser irradiation device for the protection of biological objects from the action of ionizing radiation to be used in practice has been manufactured (invention patent RU 2 428 228 C2). This device is used to study the action of various doses of laser radiation and combined irradiation with laser and gamma-radiation, on peripheral blood parameters and number of bone marrow karyocytes of the experimental mice line C57BL/6. The mice were irradiated with ionizing and laser radiation, separately one by one in a special bench. The time interval between two types of irradiation did not exceed 30 min. First, the mice were exposed to γ-radiation then to laser radiation. It was shown that laser radiation can be applied to improve the recovery of hemato genesis after the action of ionizing radiation on biological objects. Then, experiments were conducted to study the action of γ- rays and the combined action of laser radiation and γ -rays on survival, weight and skin of experimental mice. The authors investigated also the action of gamma-rays and combined effects of 650 nm laser radiation and gamma-rays on general mitotic index of bone marrow cells of mice. The method of the laser radiation-protection of biological objects contributes to an increase in the viability of mice, prevents the damages of skin and also increases the mitotic activity of mice bone marrow cells. (authors)

  19. Protective Effect of Selected Medicinal Plants against Hydrogen Peroxide Induced Oxidative Damage on Biological Substrates

    Directory of Open Access Journals (Sweden)

    Namratha Pai Kotebagilu

    2014-01-01

    Full Text Available Oxidative stress is developed due to susceptibility of biological substrates to oxidation by generation of free radicals. In degenerative diseases, oxidative stress level can be reduced by antioxidants which neutralize free radicals. Primary objective of this work was to screen four medicinal plants, namely, Andrographis paniculata, Costus speciosus, Canthium parviflorum, and Abrus precatorius, for their antioxidant property using two biological substrates—RBC and microsomes. The antioxidative ability of three solvent extracts, methanol (100% and 80% and aqueous leaf extracts, was studied at different concentrations by thiobarbituric acid reactive substances method using Fenton’s reagent to induce oxidation in the substrates. The polyphenol and flavonoid content were analyzed to relate with the observed antioxidant effect of the extracts. The phytochemical screening indicated the presence of flavonoids, polyphenols, tannins, and β-carotene in the samples. In microsomes, 80% methanol extract of Canthium and Costus and, in RBC, 80% methanol extract of Costus showed highest inhibition of oxidation and correlated well with the polyphenol and flavonoid content. From the results it can be concluded that antioxidants from medicinal plants are capable of inhibiting oxidation in biological systems, suggesting scope for their use as nutraceuticals.

  20. Protective Effect of Selected Medicinal Plants against Hydrogen Peroxide Induced Oxidative Damage on Biological Substrates.

    Science.gov (United States)

    Pai Kotebagilu, Namratha; Reddy Palvai, Vanitha; Urooj, Asna

    2014-01-01

    Oxidative stress is developed due to susceptibility of biological substrates to oxidation by generation of free radicals. In degenerative diseases, oxidative stress level can be reduced by antioxidants which neutralize free radicals. Primary objective of this work was to screen four medicinal plants, namely, Andrographis paniculata, Costus speciosus, Canthium parviflorum, and Abrus precatorius, for their antioxidant property using two biological substrates-RBC and microsomes. The antioxidative ability of three solvent extracts, methanol (100% and 80%) and aqueous leaf extracts, was studied at different concentrations by thiobarbituric acid reactive substances method using Fenton's reagent to induce oxidation in the substrates. The polyphenol and flavonoid content were analyzed to relate with the observed antioxidant effect of the extracts. The phytochemical screening indicated the presence of flavonoids, polyphenols, tannins, and β-carotene in the samples. In microsomes, 80% methanol extract of Canthium and Costus and, in RBC, 80% methanol extract of Costus showed highest inhibition of oxidation and correlated well with the polyphenol and flavonoid content. From the results it can be concluded that antioxidants from medicinal plants are capable of inhibiting oxidation in biological systems, suggesting scope for their use as nutraceuticals. PMID:25436152

  1. Honey bee (Apis mellifera) drones survive oxidative stress due to increased tolerance instead of avoidance or repair of oxidative damage.

    Science.gov (United States)

    Li-Byarlay, Hongmei; Huang, Ming Hua; Simone-Finstrom, Michael; Strand, Micheline K; Tarpy, David R; Rueppell, Olav

    2016-10-01

    Oxidative stress can lead to premature aging symptoms and cause acute mortality at higher doses in a range of organisms. Oxidative stress resistance and longevity are mechanistically and phenotypically linked; considerable variation in oxidative stress resistance exists among and within species and typically covaries with life expectancy. However, it is unclear whether stress-resistant, long-lived individuals avoid, repair, or tolerate molecular damage to survive longer than others. The honey bee (Apis mellifera L.) is an emerging model system that is well-suited to address this question. Furthermore, this species is the most economically important pollinator, whose health may be compromised by pesticide exposure, including oxidative stressors. Here, we develop a protocol for inducing oxidative stress in honey bee males (drones) via Paraquat injection. After injection, individuals from different colony sources were kept in common social conditions to monitor their survival compared to saline-injected controls. Oxidative stress was measured in susceptible and resistant individuals. Paraquat drastically reduced survival but individuals varied in their resistance to treatment within and among colony sources. Longer-lived individuals exhibited higher levels of lipid peroxidation than individuals dying early. In contrast, the level of protein carbonylation was not significantly different between the two groups. This first study of oxidative stress in male honey bees suggests that survival of an acute oxidative stressor is due to tolerance, not prevention or repair, of oxidative damage to lipids. It also demonstrates colony differences in oxidative stress resistance that might be useful for breeding stress-resistant honey bees. PMID:27422326

  2. Hepatic DNA Damage and Abnormality in Serum Protein Pattern Due to Long Term Use of Tramadol in Rats

    Directory of Open Access Journals (Sweden)

    Laila Abd El kawy

    2012-10-01

    of the comet tail relative to the head reflects the number of DNA breaks. The rates of tailed cells detected by the comet assay increased significantly when the rats were exposed to 200 and 400mg/kg of tramal compared with control (however, the tail length did not differ significantly between the same groups. The intensity of the comet tail relative to the head reflects the number of DNA breaks.Conclusions:Our findings pointed out the risk of increased lipid peroxidation, hepatic DNA damage and abnormality in serum protein pattern due to long term use of tramadol, although opioids are reported to be effective in pain management, their toxic effects should be kept in mind.

  3. 地震引发公路桥梁破损成因分析%Causes Analysis of Highway Bridge Damage Due to Earthquake

    Institute of Scientific and Technical Information of China (English)

    董丽艳

    2012-01-01

    The expressions of seismic damage of bridge due to earthquake is introduced, the causes of appearing seismic damage is analyzed, specific measures for preventing seismic damage are proposed and suggestions forquakeproof design are proposed.%介绍了地震引发的桥梁震害的表现状态,分析了发生震害的成因,并对震害的防治提出了具体措施,对防震设计提出了建议。

  4. Enzymatic recognition of DNA damage induced by UVB-photosensitized titanium dioxide and biological consequences in Saccharomyces cerevisiae: Evidence for oxidatively DNA damage generation

    International Nuclear Information System (INIS)

    Although titanium dioxide (TiO2) has been considered to be biologically inert, finding use in cosmetics, paints and food colorants, recent reports have demonstrated that when TiO2 is attained by UVA radiation oxidative genotoxic and cytotoxic effects are observed in living cells. However, data concerning TiO2-UVB association is poor, even if UVB radiation represents a major environmental carcinogen. Herein, we investigated DNA damage, repair and mutagenesis induced by TiO2 associated with UVB irradiation in vitro and in vivo using Saccharomyces cerevisiae model. It was found that TiO2 plus UVB treatment in plasmid pUC18 generated, in addition to cyclobutane pyrimidine dimers (CPDs), specific damage to guanine residues, such as 8-oxo-7,8-dihydroguanine (8-oxoG) and 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FapyG), which are characteristic oxidatively generated lesions. In vivo experiments showed that, although the presence of TiO2 protects yeast cells from UVB cytotoxicity, high mutation frequencies are observed in the wild-type (WT) and in an ogg1 strain (deficient in 8-oxoG and FapyG repair). Indeed, after TiO2 plus UVB treatment, induced mutagenesis was drastically enhanced in ogg1 cells, indicating that mutagenic DNA lesions are repaired by the Ogg1 protein. This effect could be attenuated by the presence of metallic ion chelators: neocuproine or dipyridyl, which partially block oxidatively generated damage occurring via Fenton reactions. Altogether, the results indicate that TiO2 plus UVB potentates UVB oxidatively generated damage to DNA, possibly via Fenton reactions involving the production of DNA base damage, such as 8-oxo-7,8-dihydroguanine.

  5. Enzymatic recognition of DNA damage induced by UVB-photosensitized titanium dioxide and biological consequences in Saccharomyces cerevisiae: Evidence for oxidatively DNA damage generation

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, A. Viviana, E-mail: alicia.pinto@incqs.fiocruz.br [Laboratorio de Diagnostico Molecular e Hematologia, Faculdade de Farmacia, Universidade Federal do Rio de Janeiro, Centro de Ciencias da Saude - Ilha do Fundao, CEP 21941-540, Rio de Janeiro (Brazil); Laboratorio de Radiobiologia Molecular, Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Centro de Ciencias da Saude - Ilha do Fundao, CEP 21949-900, Rio de Janeiro (Brazil); Deodato, Elder L. [Laboratorio de Diagnostico Molecular e Hematologia, Faculdade de Farmacia, Universidade Federal do Rio de Janeiro, Centro de Ciencias da Saude - Ilha do Fundao, CEP 21941-540, Rio de Janeiro (Brazil); Laboratorio de Radiobiologia Molecular, Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Centro de Ciencias da Saude - Ilha do Fundao, CEP 21949-900, Rio de Janeiro (Brazil); Cardoso, Janine S. [Laboratorio de Radiobiologia Molecular, Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Centro de Ciencias da Saude - Ilha do Fundao, CEP 21949-900, Rio de Janeiro (Brazil); Oliveira, Eliza F.; Machado, Sergio L.; Toma, Helena K. [Laboratorio de Diagnostico Molecular e Hematologia, Faculdade de Farmacia, Universidade Federal do Rio de Janeiro, Centro de Ciencias da Saude - Ilha do Fundao, CEP 21941-540, Rio de Janeiro (Brazil); Leitao, Alvaro C. [Laboratorio de Radiobiologia Molecular, Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Centro de Ciencias da Saude - Ilha do Fundao, CEP 21949-900, Rio de Janeiro (Brazil); Padula, Marcelo de [Laboratorio de Diagnostico Molecular e Hematologia, Faculdade de Farmacia, Universidade Federal do Rio de Janeiro, Centro de Ciencias da Saude - Ilha do Fundao, CEP 21941-540, Rio de Janeiro (Brazil)

    2010-06-01

    Although titanium dioxide (TiO{sub 2}) has been considered to be biologically inert, finding use in cosmetics, paints and food colorants, recent reports have demonstrated that when TiO{sub 2} is attained by UVA radiation oxidative genotoxic and cytotoxic effects are observed in living cells. However, data concerning TiO{sub 2}-UVB association is poor, even if UVB radiation represents a major environmental carcinogen. Herein, we investigated DNA damage, repair and mutagenesis induced by TiO{sub 2} associated with UVB irradiation in vitro and in vivo using Saccharomyces cerevisiae model. It was found that TiO{sub 2} plus UVB treatment in plasmid pUC18 generated, in addition to cyclobutane pyrimidine dimers (CPDs), specific damage to guanine residues, such as 8-oxo-7,8-dihydroguanine (8-oxoG) and 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FapyG), which are characteristic oxidatively generated lesions. In vivo experiments showed that, although the presence of TiO{sub 2} protects yeast cells from UVB cytotoxicity, high mutation frequencies are observed in the wild-type (WT) and in an ogg1 strain (deficient in 8-oxoG and FapyG repair). Indeed, after TiO{sub 2} plus UVB treatment, induced mutagenesis was drastically enhanced in ogg1 cells, indicating that mutagenic DNA lesions are repaired by the Ogg1 protein. This effect could be attenuated by the presence of metallic ion chelators: neocuproine or dipyridyl, which partially block oxidatively generated damage occurring via Fenton reactions. Altogether, the results indicate that TiO{sub 2} plus UVB potentates UVB oxidatively generated damage to DNA, possibly via Fenton reactions involving the production of DNA base damage, such as 8-oxo-7,8-dihydroguanine.

  6. [Left hand clumsiness due to disturbance of kinesthesia after damage to the dorsal column of the high cervical cord].

    Science.gov (United States)

    Hashimoto, R; Kanho, M; Fujimoto, K; Tanaka, Y

    1997-04-01

    We described a 48-year-old, right-handed woman who manifested left hand clumsiness after damage to the dorsal column of the high cervical cord due to probable multiple sclerosis. On February 29, 1996, she developed a weakness in the right limbs. Subsequently, she suffered numbness and clumsiness in the left limbs, even though muscle strength of the left limbs was preserved. Seventeen days later, she was referred to our hospital. A T2-weighted MRI after admission demonstrated high signal intensities in the left dorsal column and the right antero-lateral part of the cervical cord at the C1 to C3 vertebral level. Under the diagnosis of probable multiple sclerosis, steroid pulse therapy was applied twice and she gradually regained muscle strength in the right limbs and sensation in the left limbs. One month later, elemental sensations such as pain, touch, temperature, vibration, and position, as well as discriminative sensations such as localization sensation, two-point discrimination, barognosis, pinch-press discrimination, and graphesthesia in the left limbs returned to normal. However, her left hand remained clumsy, especially when she tried to manipulate objects. She also showed a great difficulty in sustaining a constant level of pinching force by the left thumb and index finger, and in localizing her right thumb placed in space with the left hand with her eyes closed. She stated herself that she could not sense at all how her left hand and fingers were moving. Somatosensory evoked potentials recorded from the right scalp showed that the NI was poorly organized and the patency of subsequent peaks was delayed. Transcranial magnetic stimulation revealed that the pyramidal tract from the right motor cortex to the left cervical cord was functionally intact. These observations lead us to conclude as follows: (1) the patient's left hand clumsiness is probably due to the disturbance of kinesthesia, which is crucial to activate temporo-spatial patterns of complex hand and

  7. Biological Signatures of Brain Damage Associated with High Serum Ferritin Levels in Patients with Acute Ischemic Stroke and Thrombolytic Treatment

    Directory of Open Access Journals (Sweden)

    Mónica Millán

    2008-01-01

    Full Text Available Background and purpose: Increased body iron stores have been related to greater oxidative stress and brain injury in clinical and experimental cerebral ischemia and reperfusion. We aimed to investigate the biological signatures of excitotoxicity, inflammation and blood brain barrier disruption potentially associated with high serum ferritin levels-related damage in acute stroke patients treated with i.v. t-PA.

  8. DESIGN LOAD EVALUATION FOR TSUNAMI SHELTERS BASED ON DAMAGE OBSERVATIONS AFTER INDIAN OCEAN TSUNAMI DISASTER DUE TO THE 2004 SUMATRA EARTHQUAKE

    Directory of Open Access Journals (Sweden)

    Y. Nakano

    2010-01-01

    Full Text Available Tsunami shelters are of great importance to mitigate casualties by earthquake-induced killer waves, and the design guidelines for their practical design are recently developed by a task committee under the Japanese Cabinet Office, since great earthquakes significantly affecting coastal regions are expected to occur in the near future in Japan. Although they propose a practical design formula to calculate tsunami loads acting on shelters, it is derived primarily based on laboratory tests with scaled models but not on damage observations. It is therefore essential to examine the design loads through comparison between observed damage and structural strength. In December 2004, a huge scale Sumatra Earthquake caused extensive and catastrophic damage to 12 countries in the Indian Ocean. The author visited Sri Lanka and Thailand to survey structural damage due to tsunami, and investigated the relationship between damage to structures, lateral strengths computed based on their member properties, and observed tsunami heights. In the survey, 28 simple structures generally found in the affected coastal regions were investigated. The investigated results show that the design tsunami loads proposed in the guidelines are found rational to avoid serious damage but may not be conservative if the load amplification due to drifting debris is taken into account.

  9. Nanoparticle-aided Radiation Therapy: Micro-dosimetry and Evaluation of the Mediators Producing Biological Damage

    Science.gov (United States)

    Paudel, Nava Raj

    Radiation therapy has been established as a standard technique for cancer treatment. Advances in nanotechnology have enabled the application of many new approaches in the diagnosis and treatment of cancer. Achievement of selective enhancement in radiation dose deposition within a targeted tumor, while sparing surrounding normal structures, remains a challenge and one of the major objectives of cancer-related research. This objective can be realized by the insertion of high atomic number (Z) materials in the tumor site. Due to their high atomic number (Z=79) and favorable biological compatibility, gold nanoparticles (AuNPs) have been found very promising in this respect. Another candidate material, platinum (Z=78), offering very similar radiation interaction properties to gold and exhibiting additional cytotoxic effects, has been exploited in chemotherapeutic agents for a long time. We explore the radiation effects near the interface of gold and platinum with tissue under a wide range of energies with Monte Carlo (MC) simulations. Our studies show that AuNPs and PtNPs (platinum nanoparticles) can offer a useful dose enhancement effect even in high energy radiotherapy beams, which can be important when critical structures are located close to the tumor. Our MC calculated dose enhancement increase of about 50% due to the removal of the flattening filter from the path of the photon beam of Varian TrueBeam accelerator suggests that flattening-filter-free beams are better suited for nanoparticle-aided radiation therapy. Also, the increase in dose enhancement with the tumor depth suggests that nanopartcle-aided radiation therapy can yield a better outcome while treating deep-seated tumors. Experimental microdosimetry is a non-trivial task, demanding detectors with small sensitive volumes to achieve a high spatial resolution. We have developed a microdosimetry technique utilizing an inexpensive in-house-built photodetector for the measurement of dose in a narrow high dose

  10. The Biological Effectiveness of Different Radiation Qualities for the Induction of Chromosome Damage in Human Lymphocytes

    Science.gov (United States)

    Hada, M.; George, Kerry; Cucinotta, F. A.

    2011-01-01

    Chromosome aberrations were measured in human peripheral blood lymphocytes after in vitro exposure to Si-28-ions with energies ranging from 90 to 600 MeV/u, Ti-48-ions with energies ranging from 240 to 1000 MeV/u, or to Fe-56-ions with energies ranging from 200 to 5,000 MeV/u. The LET of the various Si beams in this study ranged from 48 to 158 keV/ m, the LET of the Ti ions ranged from 107 to 240 keV/micron, and the LET of the Fe-ions ranged from 145 to 440 keV/ m. Doses delivered were in the 10- to 200-cGy range. Dose-response curves for chromosome exchanges in cells at first division after exposure, measured using fluorescence in situ hybridization (FISH) with whole-chromosome probes, were fitted with linear or linear-quadratic functions. The relative biological effectiveness (RBE) was estimated from the initial slope of the dose-response curve for chromosome damage with respect to gamma-rays. The estimates of RBEmax values for total chromosome exchanges ranged from 4.4+/-0.4 to 31.5+/-2.6 for Fe ions, 21.4+/-1.7 to 28.3+/-2.4 for Ti ions, and 11.8+/-1.0 to 42.2+/-3.3 for Si ions. The highest RBEmax value for Fe ions was obtained with the 600 MeV/u beam, the highest RBEmax value for Ti ions was obtained 1000 MeV/u beam, and the highest RBEmax value for Si ions was obtained with the 170 MeV/u beam. For Si and Fe ions the RBEmax values increased with LET, reaching a maximum at about 180 keV/micron for Fe and about 100 keV/micron for Si, and decreasing with further increase in LET. Additional studies for low doses Si-28-ions down to 0.02 Gy will be discussed.

  11. ESTIMATION OF DAMAGED AREAS DUE TO THE 2010 CHILE EARTHQUAKE AND TSUNAMI USING SAR IMAGERY OF ALOS/PALSAR

    Directory of Open Access Journals (Sweden)

    P. J. Ni Made

    2016-06-01

    Full Text Available A large-scale earthquake and tsunami affect thousands of people and cause serious damages worldwide every year. Quick observation of the disaster damage is extremely important for planning effective rescue operations. In the past, acquiring damage information was limited to only field surveys or using aerial photographs. In the last decade, space-borne images were used in many disaster researches, such as tsunami damage detection. In this study, SAR data of ALOS/PALSAR satellite images were used to estimate tsunami damage in the form of inundation areas in Talcahuano, the area near the epicentre of the 2010 Chile earthquake. The image processing consisted of three stages, i.e. pre-processing, analysis processing, and post-processing. It was conducted using multi-temporal images before and after the disaster. In the analysis processing, inundation areas were extracted through the masking processing. It consisted of water masking using a high-resolution optical image of ALOS/AVNIR-2 and elevation masking which built upon the inundation height using DEM image of ASTER-GDEM. The area result was 8.77 Km2. It showed a good result and corresponded to the inundation map of Talcahuano. Future study in another area is needed in order to strengthen the estimation processing method.

  12. Analysis of core damage frequency due to external events at the DOE [Department of Energy] N-Reactor

    International Nuclear Information System (INIS)

    A complete external events probabilistic risk assessment has been performed for the N-Reactor power plant, making full use of all insights gained during the past ten years' developments in risk assessment methodologies. A detailed screening analysis was performed which showed that all external events had negligible contribution to core damage frequency except fires, seismic events, and external flooding. A limited scope analysis of the external flooding risk indicated that it is not a major risk contributor. Detailed analyses of the fire and seismic risks resulted in total (mean) core damage frequencies of 1.96E-5 and 4.60E-05 per reactor year, respectively. Detailed uncertainty analyses were performed for both fire and seismic risks. These results show that the core damage frequency profile for these events is comparable to that found for existing commercial power plants if proposed fixes are completed as part of the restart program. 108 refs., 85 figs., 80 tabs

  13. Analysis of core damage frequency due to external events at the DOE (Department of Energy) N-Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lambright, J.A.; Bohn, M.P.; Daniel, S.L. (Sandia National Labs., Albuquerque, NM (USA)); Baxter, J.T. (Westinghouse Hanford Co., Richland, WA (USA)); Johnson, J.J.; Ravindra, M.K.; Hashimoto, P.O.; Mraz, M.J.; Tong, W.H.; Conoscente, J.P. (EQE, Inc., San Francisco, CA (USA)); Brosseau, D.A. (ERCE, Inc., Albuquerque, NM (USA))

    1990-11-01

    A complete external events probabilistic risk assessment has been performed for the N-Reactor power plant, making full use of all insights gained during the past ten years' developments in risk assessment methodologies. A detailed screening analysis was performed which showed that all external events had negligible contribution to core damage frequency except fires, seismic events, and external flooding. A limited scope analysis of the external flooding risk indicated that it is not a major risk contributor. Detailed analyses of the fire and seismic risks resulted in total (mean) core damage frequencies of 1.96E-5 and 4.60E-05 per reactor year, respectively. Detailed uncertainty analyses were performed for both fire and seismic risks. These results show that the core damage frequency profile for these events is comparable to that found for existing commercial power plants if proposed fixes are completed as part of the restart program. 108 refs., 85 figs., 80 tabs.

  14. V-79 Chinese Hamster Cells irradiated with antiprotons, a study of peripheral damage due to medium and long range components of the annihilation radiation

    DEFF Research Database (Denmark)

    Kovacevic, Sandra; Bassler, Niels; Hartley, Oliver;

    2009-01-01

    Purpose: Radiotherapy of cancer carries a perceived risk of inducing secondary cancer and other damage due to dose delivered to normal tissue. While expectedly small, this risk must be carefully analysed for all modalities. Especially in the use of exotic particles like pions and antiprotons, which...

  15. Urinary 8-hydroxy-2'-deoxyguanosine as a biological marker of in vivo oxidative DNA damage

    International Nuclear Information System (INIS)

    DNA is subject to constant oxidative damage from endogenous oxidants. The oxidized DNA is continuously repaired and the oxidized bases are excreted in the urine. A simple routine analytical procedure is described for urinary 8-hydroxy-2'-deoxyguanosine, an oxidative DNA damage adduct, as an indicator of oxidative damage in humans and rodents. This adduct was purified from human urine and characterized. The described assay employs a series of solid-phase extraction steps that separate 8-hydroxy-2'-deoxyguanosine from other urinary constituents, followed by analysis by gradient reversed-phase HPLC coupled to a dual-electrode high-efficient electrochemical detection system. Analysis of urine from three species by this method indicates that mice excrete approximately 3.3-fold more 8-hydroxy-2'-deoxyguanosine than humans (582 vs. 178 residues per cell day), a result that supports the proposal that oxidative damage to DNA increases in proportion to species-specific basal metabolic rates

  16. DNA Mismatch Repair and Oxidative DNA Damage: Implications for Cancer Biology and Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Bridge, Gemma; Rashid, Sukaina; Martin, Sarah A., E-mail: sarah.martin@qmul.ac.uk [Centre for Molecular Oncology, Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ (United Kingdom)

    2014-08-05

    Many components of the cell, including lipids, proteins and both nuclear and mitochondrial DNA, are vulnerable to deleterious modifications caused by reactive oxygen species. If not repaired, oxidative DNA damage can lead to disease-causing mutations, such as in cancer. Base excision repair and nucleotide excision repair are the two DNA repair pathways believed to orchestrate the removal of oxidative lesions. However, recent findings suggest that the mismatch repair pathway may also be important for the response to oxidative DNA damage. This is particularly relevant in cancer where mismatch repair genes are frequently mutated or epigenetically silenced. In this review we explore how the regulation of oxidative DNA damage by mismatch repair proteins may impact on carcinogenesis. We discuss recent studies that identify potential new treatments for mismatch repair deficient tumours, which exploit this non-canonical role of mismatch repair using synthetic lethal targeting.

  17. DNA Mismatch Repair and Oxidative DNA Damage: Implications for Cancer Biology and Treatment

    International Nuclear Information System (INIS)

    Many components of the cell, including lipids, proteins and both nuclear and mitochondrial DNA, are vulnerable to deleterious modifications caused by reactive oxygen species. If not repaired, oxidative DNA damage can lead to disease-causing mutations, such as in cancer. Base excision repair and nucleotide excision repair are the two DNA repair pathways believed to orchestrate the removal of oxidative lesions. However, recent findings suggest that the mismatch repair pathway may also be important for the response to oxidative DNA damage. This is particularly relevant in cancer where mismatch repair genes are frequently mutated or epigenetically silenced. In this review we explore how the regulation of oxidative DNA damage by mismatch repair proteins may impact on carcinogenesis. We discuss recent studies that identify potential new treatments for mismatch repair deficient tumours, which exploit this non-canonical role of mismatch repair using synthetic lethal targeting

  18. Doses due to tritium releases by NET - data base and relevant parameters on biological tritium behaviour

    International Nuclear Information System (INIS)

    This study gives an overview on the current knowledge about the behaviour of tritium in plants and in food chains in order to evaluate the ingestion pathway modelling of existing computer codes for dose estimations. The tritium uptake and retention by plants standing at the beginning of the food chains is described. The different chemical forms of tritium, which may be released into the atmosphere (HT, HTO and tritiated organics), and incorporation of tritium into organic material of plants are considered. Uptake and metabolism of tritiated compounds in animals and man are reviewed with particular respect to organically bound tritium and its significance for dose estimations. Some basic remarks on tritium toxicity are also included. Furthermore, a choice of computer codes for dose estimations due to chronic or accidental tritium releases has been compared with respect to the ingestion pathway. (orig.)

  19. Genetic and Biological Changes of Newcastle Disease Virus Due to The Development of Chicken Production System

    Directory of Open Access Journals (Sweden)

    Sudarisman

    2009-09-01

    Full Text Available In many countries, Newcastle Disease (ND is one of the most important diseases of poultry. It causes serious economic losses in poultry industry. Newcastle Disease or pseudo-fowl pest is a highly infectious viral disease that causes very high mortality (up to 100% in severe epidemics in poultry and wild birds around the world. Newcastle Disease remains endemic in many regions and continues to severely limit poultry production in some developing countries. The disease is currently being controlled by routine vaccinations in many countries. However, it was reported that outbreaks of ND in vaccinated flocks often occur on the field may not only be due to differences in the antigenicity of the NDV wild field strains and vaccine strains, but could also be as a result of differences in pathogenicity and virulence between different strains used as vaccine seed in NDV vaccine production.

  20. Attenuation of radiation-induced DNA damage due to paracrine interactions between normal human epithelial and stromal cells

    International Nuclear Information System (INIS)

    Complete text of publication follows. Objective: Developmentally, every tissue accommodates different types of cells, such as epitheliocytes and stromal cells in parenchymal organs. To better understand the complexity of radiation response, it is necessary to evaluate possible cross-talk between different tissue components. This work was set out to investigate reciprocal influence of normal human epithelial cells and fibroblasts on the extent of radiation-induced DNA damage. Methods: Model cultures of primary human thyrocytes (PT), normal diploid fibroblasts (BJ), PT/BJ cell co-culture and conditioned medium transfer were used to examine DNA damage in terms of γ-H2AX foci number per cell or by Comet assay after exposure to different doses of γ-rays. Results: In co-cultures, the kinetics of γ-H2AX foci number change was dose-dependent and similar to that in individual PT and BJ cultures. The number of γ-H2AX foci in co-cultures was significantly lower (∼25%) in both types of cells comparing to individual cultures. Reciprocal conditioned medium transfer to individual counterpart cells prior to irradiation resulted in approximately 35% reduction in the number γ-H2AX foci at 1 Gy and lower doses in both PT and BJ demonstrating the role of paracrine soluble factors. Comet assay corroborated the results of γ-H2AX foci counting in conditioned medium transfer experiments. In contrast to medium conditioned on PT cells, conditioned medium collected from several human thyroid cancer cell lines failed to establish DNA-protected state in BJ fibroblasts. In its turn, medium conditioned on BJ cells did not change the extent of radiation-induced DNA damage in cancer cell lines tested. Conclusion: The results imply the existence of a network of soluble factor-mediated paracrine interactions between normal epithelial and stromal cells that could be a part of natural mechanism by which cells protect DNA from genotoxic stress.

  1. Investigations of Pulmonary Epithelial Cell Damage due to Air-Liquid Interfacial Stresses in a Microgravity Environment

    Science.gov (United States)

    Gaver, Donald P., III; Bilek, A. M.; Kay, S.; Dee, K. C.

    2004-01-01

    Pulmonary airway closure is a potentially dangerous event that can occur in microgravity environments and may result in limited gas exchange for flight crew during long-term space flight. Repetitive airway collapse and reopening subjects the pulmonary epithelium to large, dynamic, and potentially injurious mechanical stresses. During ventilation at low lung volumes and pressures, airway instability leads to repetitive collapse and reopening. During reopening, air must progress through a collapsed airway, generating stresses on the airway walls, potentially damaging airway tissues. The normal lung can tolerate repetitive collapse and reopening. However, combined with insufficient or dysfunctional pulmonary surfactant, repetitive airway collapse and reopening produces severe lung injury. Particularly at risk is the pulmonary epithelium. As an important regulator of lung function and physiology, the degree of pulmonary epithelial damage influences the course and outcome of lung injury. In this paper we present experimental and computational studies to explore the hypothesis that the mechanical stresses associated with airway reopening inflict injury to the pulmonary epithelium.

  2. Extent, perception and mitigation of damage due to high groundwater levels in the city of Dresden, Germany

    Science.gov (United States)

    Kreibich, H.; Thieken, A. H.; Grunenberg, H.; Ullrich, K.; Sommer, T.

    2009-07-01

    Flood risk analysis and management plans mostly neglect groundwater flooding, i.e. high groundwater levels. However, rising groundwater may cause considerable damage to buildings and infrastructure. To improve the knowledge about groundwater flooding and support risk management, a survey was undertaken in the city of Dresden (Saxony, Germany), resulting in 605 completed interviews with private households endangered by high groundwater levels. The reported relatively low flood impact and damage of groundwater floods in comparison with mixed floods was reflected by its scarce perception: Hardly anybody thinks about the risk of groundwater flooding. The interviewees thought that public authorities and not themselves, should be mainly responsible for preparedness and emergency response. Up to now, people do not include groundwater risk in their decision processes on self protection. The implementation of precautionary measures does not differ between households with groundwater or with mixed flood experience. However, less households undertake emergency measures when expecting a groundwater flood only. The state of preparedness should be further improved via an intensified risk communication about groundwater flooding by the authorities. Conditions to reach the endangered population are good, since 70% of the interviewed people are willing to inform themselves about groundwater floods. Recommendations for an improved risk communication are given.

  3. An assessment of the resolution limitation due to radiation-damage in x-ray diffraction microscopy

    CERN Document Server

    Howells, M R; Chapman, H N; Cui, C; Holton, J M; Jacobsen, C J; Lima, J K E; Marchesini, S; Miao, H; Sayre, D; Shapiro, D A; Spence, J C H

    2005-01-01

    X-ray diffraction microscopy (XDM) is a new form of x-ray imaging that is being practiced at several third-generation synchrotron-radiation x-ray facilities. Although only five years have elapsed since the technique was first introduced, it has made rapid progress in demonstrating high-resolution threedimensional imaging and promises few-nm resolution with much larger samples than can be imaged in the transmission electron microscope. Both life- and materials-science applications of XDM are intended, and it is expected that the principal limitation to resolution will be radiation damage for life science and the coherent power of available x-ray sources for material science. In this paper we address the question of the role of radiation damage. We use a statistical analysis based on the so-called "dose fractionation theorem" of Hegerl and Hoppe to calculate the dose needed to make an image of a lifescience sample by XDM with a given resolution. We conclude that the needed dose scales with the inverse fourth po...

  4. Scenario-based assessment of buildings damage and population exposure due to tsunamis for the town of Alexandria, Egypt

    Science.gov (United States)

    Pagnoni, G.; Armigliato, A.; Tinti, S.

    2015-08-01

    Alexandria is the second biggest city in Egypt as regards population, is a key economic area in northern Africa and has a very important tourist activity. Historical catalogues indicate that it was severely affected by a number of tsunami events. In this work we assess the tsunami hazard by running numerical simulations of tsunami impact in Alexandria through the Worst-case Credible Tsunami Scenario Analysis (WCTSA). We identify three main seismic sources: the Western Hellenic Arc (WHA - reference event AD 365, Mw = 8.5), the Eastern Hellenic Arc (EHA - reference event 1303, Mw = 8.0) and the Cyprus Arc (CA - hypothetical scenario earthquake with Mw = 8.0), inferred from the tectonic setting and from historical tsunami catalogues. All numerical simulations are carried out by means of the code UBO-TSUFD, developed and maintained by the Tsunami Research Team of the University of Bologna. Relevant tsunami metrics are computed for each scenario and then used to build aggregated fields such as the maximum flood depth and the maximum inundation area. We find that the case that produces the most relevant flooding in Alexandria is the EHA scenario, with wave heights up to 4 m. The aggregate fields are used for a building vulnerability assessment according to a methodology developed in the frame of the EU-FP6 project SCHEMA and further refined in this study, based on the adoption of a suitable building damage matrix and on water inundation depth. It is found that in the districts of El Dekhila and Al Amriyah, to the south-west of the port of Dekhila over 12 000 buildings could be affected and hundreds of them could incur in consequences ranging from important damage to total collapse. It is also found that in the same districts tsunami inundation covers an area of about 15 km2 resulting in more than 150 000 residents being exposed.

  5. Scenario-based assessment of buildings damage and population exposure due to tsunamis for the town of Alexandria, Egypt

    Directory of Open Access Journals (Sweden)

    G. Pagnoni

    2015-08-01

    Full Text Available Alexandria is the second biggest city in Egypt as regards population, is a key economic area in northern Africa and has a very important tourist activity. Historical catalogues indicate that it was severely affected by a number of tsunami events. In this work we assess the tsunami hazard by running numerical simulations of tsunami impact in Alexandria through the Worst-case Credible Tsunami Scenario Analysis (WCTSA. We identify three main seismic sources: the Western Hellenic Arc (WHA – reference event AD 365, Mw = 8.5, the Eastern Hellenic Arc (EHA – reference event 1303, Mw = 8.0 and the Cyprus Arc (CA – hypothetical scenario earthquake with Mw = 8.0, inferred from the tectonic setting and from historical tsunami catalogues. All numerical simulations are carried out by means of the code UBO-TSUFD, developed and maintained by the Tsunami Research Team of the University of Bologna. Relevant tsunami metrics are computed for each scenario and then used to build aggregated fields such as the maximum flood depth and the maximum inundation area. We find that the case that produces the most relevant flooding in Alexandria is the EHA scenario, with wave heights up to 4 m. The aggregate fields are used for a building vulnerability assessment according to a methodology developed in the frame of the EU-FP6 project SCHEMA and further refined in this study, based on the adoption of a suitable building damage matrix and on water inundation depth. It is found that in the districts of El Dekhila and Al Amriyah, to the south-west of the port of Dekhila over 12 000 buildings could be affected and hundreds of them could incur in consequences ranging from important damage to total collapse. It is also found that in the same districts tsunami inundation covers an area of about 15 km2 resulting in more than 150 000 residents being exposed.

  6. Biological consequences of potential repair intermediates of clustered base damage site in Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Shikazono, Naoya, E-mail: shikazono.naoya@jaea.go.jp [Japan Atomic Energy Agency, Advanced Research Science Center, 2-4 Shirakata-Shirane, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); O' Neill, Peter [Gray Institute for Radiation Oncology and Biology, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ (United Kingdom)

    2009-10-02

    Clustered DNA damage induced by a single radiation track is a unique feature of ionizing radiation. Using a plasmid-based assay in Escherichia coli, we previously found significantly higher mutation frequencies for bistranded clusters containing 7,8-dihydro-8-oxoguanine (8-oxoG) and 5,6-dihydrothymine (DHT) than for either a single 8-oxoG or a single DHT in wild type and in glycosylase-deficient strains of E. coli. This indicates that the removal of an 8-oxoG from a clustered damage site is most likely retarded compared to the removal of a single 8-oxoG. To gain further insights into the processing of bistranded base lesions, several potential repair intermediates following 8-oxoG removal were assessed. Clusters, such as DHT + apurinic/apyrimidinic (AP) and DHT + GAP have relatively low mutation frequencies, whereas clusters, such as AP + AP or GAP + AP, significantly reduce the number of transformed colonies, most probably through formation of a lethal double strand break (DSB). Bistranded AP sites placed 3' to each other with various interlesion distances also blocked replication. These results suggest that bistranded base lesions, i.e., single base lesions on each strand, but not clusters containing only AP sites and strand breaks, are repaired in a coordinated manner so that the formation of DSBs is avoided. We propose that, when either base lesion is initially excised from a bistranded base damage site, the remaining base lesion will only rarely be converted into an AP site or a single strand break in vivo.

  7. New Computational Model Based on Finite Element Method to Quantify Damage Evolution Due to External Sulfate Attack on Self-Compacting Concretes

    KAUST Repository

    Khelifa, Mohammed Rissel

    2012-12-27

    Abstract: This work combines experimental and numerical investigations to study the mechanical degradation of self-compacting concrete under accelerated aging conditions. Four different experimental treatments are tested among them constant immersion and immersion-drying protocols allow an efficient external sulfate attack of the material. Significant damage is observed due to interfacial ettringite. A predictive analysis is then adopted to quantify the relationship between ettringite growth and mechanical damage evolution during aging. Typical 3D microstructures representing the cement paste-aggregate structures are generated using Monte Carlo scheme. These images are converted into a finite element model to predict the mechanical performance under different criteria of damage kinetics. The effect of ettringite is then associated to the development of an interphase of lower mechanical properties. Our results show that the observed time evolution of Young\\'s modulus is best described by a linear increase of the interphase content. Our model results indicate also that the interphase regions grow at maximum stress regions rather than exclusively at interfaces. Finally, constant immersion predicts a rate of damage growth five times lower than that of immersion-drying protocol. © 2012 Computer-Aided Civil and Infrastructure Engineering.

  8. Modeling marrow damage from response data: evolution from radiation biology to benzene toxicity.

    OpenAIRE

    Jones, D T; Morris, M D; Hasan, J S

    1996-01-01

    Consensus principles from radiation biology were used to describe a generic set of nonlinear, first-order differential equations for modeling toxicity-induced compensatory cell kinetics in terms of sublethal injury, repair, direct killing, killing of cells with unrepaired sublethal injury, and repopulation. This cellular model was linked to a probit model of hematopoietic mortality that describes death from infection and/or hemorrhage between 5 and 30 days. Mortality data from 27 experiments ...

  9. Membrane lysis during biological membrane fusion: collateral damage by misregulated fusion machines

    OpenAIRE

    Engel, Alex; Walter, Peter

    2008-01-01

    In the canonical model of membrane fusion, the integrity of the fusing membranes is never compromised, preserving the identity of fusing compartments. However, recent molecular simulations provided evidence for a pathway to fusion in which holes in the membrane evolve into a fusion pore. Additionally, two biological membrane fusion models—yeast cell mating and in vitro vacuole fusion—have shown that modifying the composition or altering the relative expression levels of membrane fusion comple...

  10. Treatment of skin damage due to irradiation and post-irradiation skin tumours, at the Hornheide special clinic

    International Nuclear Information System (INIS)

    A short precis of 54 years of history of the Hornheide special clinic for tumours, tuberculosis, and plastic surgery of face and skin is followed by a description of the current tasks of the clinic as an interdisciplinary center for plastic surgery and rehabilitation with facilities for tumour surgery, radiotherapy, skin and tissue pathology, and psychotherapy. Important special areas of this interdisciplinary cooperation are the treatment of skin disorders due to radiation and of tumours on irradiated skin, as well as treatment and plastic surgery after removal of tumours by irradiation in order to make the affected areas fit for renewed irradiation. (TRV)

  11. Is the increased relative biological effectiveness of high LET particles due to spatial or temporal effects? Characterization and OER in V79-4 cells

    International Nuclear Information System (INIS)

    The efficiency of producing biological damage varies with radiation quality. Conventional explanations rely on spatial differences in the radiation track structure; generally however there are also very large temporal differences in delivery of the radiation at the cellular level. High-LET radiation normally deposits substantial amounts of energy by individual heavily ionizing tracks on a timescale of the order of picoseconds. By contrast each low-LET radiation track deposits a small amount of energy. Many of these tracks, distributed over the whole cell, are required to deliver an equivalent dose to a high-LET track and they are usually delivered over much longer timescales (typically seconds) during which chemical, biochemical and biological processes are occurring. In this paper the design, characterization and initial application of a high-brightness, laser-plasma ultrasoft x-ray source is described. This has been used to investigate the importance of the temporal differences by irradiating mammalian cells with an energy deposition with spatial properties of low-LET radiation and temporal properties similar to high-LET radiation. The present system delivers a typical dose, to the incident surface of the cells, of 0.12 Gy per pulse delivered in <10 ps. The capabilities of the x-ray source were tested by determining the survival of V79-4 hamster cells irradiated with picosecond pulses of ultrasoft x-rays under aerobic and anaerobic conditions, which were found to be consistent with previously published non pulsed data with x-rays of similar energy. These results support the expectation that the disappearance of an oxygen effect for high-LET radiation particles is due to their spatial properties rather than the very short timescale of each particle traversal. For other effects, particularly non-targeted phenomena such as induced genomic instability, expectations may be less clear cut. (author)

  12. Laser-induced damage in biological tissue: Role of complex and dynamic optical properties of the medium

    Science.gov (United States)

    Ahmed, Elharith M.

    Since its invention in the early 1960's, the laser has been used as a tool for surgical, therapeutic, and diagnostic purposes. To achieve maximum effectiveness with the greatest margin of safety it is important to understand the mechanisms of light propagation through tissue and how that light affects living cells. Lasers with novel output characteristics for medical and military applications are too often implemented prior to proper evaluation with respect to tissue optical properties and human safety. Therefore, advances in computational models that describe light propagation and the cellular responses to laser exposure, without the use of animal models, are of considerable interest. Here, a physics-based laser-tissue interaction model was developed to predict the spatial and temporal temperature and pressure rise during laser exposure to biological tissues. Our new model also takes into account the dynamic nature of tissue optical properties and their impact on the induced temperature and pressure profiles. The laser-induced retinal damage is attributed to the formation of microbubbles formed around melanosomes in the retinal pigment epithelium (RPE) and the damage mechanism is assumed to be photo-thermal. Selective absorption by melanin creates these bubbles that expand and collapse around melanosomes, destroying cell membranes and killing cells. The Finite Element (FE) approach taken provides suitable ground for modeling localized pigment absorption which leads to a non-uniform temperature distribution within pigmented cells following laser pulse exposure. These hot-spots are sources for localized thermo-elastic stresses which lead to rapid localized expansions that manifest themselves as microbubbles and lead to microcavitations. Model predictions for the interaction of lasers at wavelengths of 193, 694, 532, 590, 1314, 1540, 2000, and 2940 nm with biological tissues were generated and comparisons were made with available experimental data for the retina

  13. Reduced-Order Modeling and Wavelet Analysis of Turbofan Engine Structural Response Due to Foreign Object Damage "FOD" Events

    Science.gov (United States)

    Turso, James A.; Lawrence, Charles; Litt, Jonathan S.

    2007-01-01

    The development of a wavelet-based feature extraction technique specifically targeting FOD-event induced vibration signal changes in gas turbine engines is described. The technique performs wavelet analysis of accelerometer signals from specified locations on the engine and is shown to be robust in the presence of significant process and sensor noise. It is envisioned that the technique will be combined with Kalman filter thermal/ health parameter estimation for FOD-event detection via information fusion from these (and perhaps other) sources. Due to the lack of high-frequency FOD-event test data in the open literature, a reduced-order turbofan structural model (ROM) was synthesized from a finite-element model modal analysis to support the investigation. In addition to providing test data for algorithm development, the ROM is used to determine the optimal sensor location for FOD-event detection. In the presence of significant noise, precise location of the FOD event in time was obtained using the developed wavelet-based feature.

  14. The Role of Inspiratory Muscle Training in Sickle Cell Anemia Related Pulmonary Damage due to Recurrent Acute Chest Syndrome Attacks.

    Science.gov (United States)

    Camcıoğlu, Burcu; Boşnak-Güçlü, Meral; Karadallı, Müşerrefe Nur; Akı, Şahika Zeynep; Türköz-Sucak, Gülsan

    2015-01-01

    Background. The sickling of red blood cells causes a constellation of musculoskeletal, cardiovascular, and pulmonary manifestations. A 32-year-old gentleman with sickle cell anemia (SCA) had been suffering from recurrent acute chest syndrome (ACS). Aim. To examine the effects of inspiratory muscle training (IMT) on pulmonary functions, respiratory and peripheral muscle strength, functional exercise capacity, and quality of life in this patient with SCA. Methods. Functional exercise capacity was evaluated using six-minute walk test, respiratory muscle strength using mouth pressure device, hand grip strength using hand-held dynamometer, pain using Visual Analogue Scale, fatigue using Fatigue Severity Scale, dyspnea using Modified Medical Research Council Scale, and health related quality of life using European Organization for Research and Treatment of Cancer QOL measurement. Results. A significant improvement has been demonstrated in respiratory muscle strength, functional exercise capacity, pain, fatigue, dyspnea, and quality of life. There was no admission to emergency department due to acute chest syndrome in the following 12 months after commencing regular erythrocytapheresis. Conclusion. This is the first report demonstrating the beneficial effects of inspiratory muscle training on functional exercise capacity, respiratory muscle strength, pain, fatigue, dyspnea, and quality of life in a patient with recurrent ACS. PMID:26060589

  15. The Role of Inspiratory Muscle Training in Sickle Cell Anemia Related Pulmonary Damage due to Recurrent Acute Chest Syndrome Attacks

    Directory of Open Access Journals (Sweden)

    Burcu Camcıoğlu

    2015-01-01

    Full Text Available Background. The sickling of red blood cells causes a constellation of musculoskeletal, cardiovascular, and pulmonary manifestations. A 32-year-old gentleman with sickle cell anemia (SCA had been suffering from recurrent acute chest syndrome (ACS. Aim. To examine the effects of inspiratory muscle training (IMT on pulmonary functions, respiratory and peripheral muscle strength, functional exercise capacity, and quality of life in this patient with SCA. Methods. Functional exercise capacity was evaluated using six-minute walk test, respiratory muscle strength using mouth pressure device, hand grip strength using hand-held dynamometer, pain using Visual Analogue Scale, fatigue using Fatigue Severity Scale, dyspnea using Modified Medical Research Council Scale, and health related quality of life using European Organization for Research and Treatment of Cancer QOL measurement. Results. A significant improvement has been demonstrated in respiratory muscle strength, functional exercise capacity, pain, fatigue, dyspnea, and quality of life. There was no admission to emergency department due to acute chest syndrome in the following 12 months after commencing regular erythrocytapheresis. Conclusion. This is the first report demonstrating the beneficial effects of inspiratory muscle training on functional exercise capacity, respiratory muscle strength, pain, fatigue, dyspnea, and quality of life in a patient with recurrent ACS.

  16. Estimation of core-damage frequency to evolutionary ALWR [advanced light water reactor] due to seismic initiating events: Task 4.3.3

    International Nuclear Information System (INIS)

    The Electric Power Research Institute (EPRI) is presently developing a requirements document for the design of advanced light water reactors (ALWRs). One of the basic goals of the EPRI ALWR Requirements Document is that the core-damage frequency for an ALWR shall be less than 1.0E-5. To aid in this effort, the Department of Energy's Advanced Reactor Severe Accident Program (ARSAP) initiated a functional probabilistic risk assessment (PRA) to determine how effectively the evolutionary plant requirements contained in the existing EPRI Requirements Document assure that this safety goal will be met. This report develops an approximation of the core-damage frequency due to seismic events for both evolutionary plant designs (pressurized-water reactor (PWR) and boiling-water reactor(BWR)) as modeled in the corresponding functional PRAs. Component fragility values were taken directly form information which has been submitted for inclusion in Appendix A to Volume 1 of the EPRI Requirements Document. The results show a seismic core-damage frequency of 5.2E-6 for PWRS and 5.0E-6 for BWRs. Combined with the internal initiators from the functional PRAs, the overall core-damage frequencies are 6.0E-6 for the pwr and BWR, both of which satisfy the 1.0E-5 EPRI goal. In addition, site-specific considerations, such as more rigid components and less conservative fragility data and seismic hazard curves, may further reduce these frequencies. The effect of seismic events on structures are not addressed in this generic evaluation and should be addressed separately on a design-specific basis. 7 refs., 6 figs., 3 tabs

  17. Modeling marrow damage from response data: Morphallaxis from radiation biology to benzene toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Jones, T.D.; Morris, M.D.; Hasan, J.S.

    1995-12-01

    Consensus principles from radiation biology were used to describe a generic set of nonlinear, first-order differential equations for modeling of toxicity-induced compensatory cell kinetics in terms of sublethal injury, repair, direct killing, killing of cells with unrepaired sublethal injury, and repopulation. This cellular model was linked to a probit model of hematopoietic mortality that describes death from infection and/or hemorrhage between {approximately} 5 and 30 days. Mortality data from 27 experiments with 851 doseresponse groups, in which doses were protracted by rate and/or fractionation, were used to simultaneously estimate all rate constants by maximum-likelihood methods. Data used represented 18,940 test animals distributed according to: (mice, 12,827); (rats, 2,925); (sheep, 1,676); (swine, 829); (dogs, 479); and (burros, 204). Although a long-term, repopulating hematopoietic stem cell is ancestral to all lineages needed to restore normal homeostasis, the dose-response data from the protracted irradiations indicate clearly that the particular lineage that is ``critical`` to hematopoietic recovery does not resemble stem-like cells with regard to radiosensitivity and repopulation rates. Instead, the weakest link in the chain of hematopoiesis was found to have an intrinsic radioresistance equal to or greater than stromal cells and to repopulate at the same rates. Model validation has been achieved by predicting the LD{sub 50} and/or fractional group mortality in 38 protracted-dose experiments (rats and mice) that were not used in the fitting of model coefficients.

  18. Modeling marrow damage from response data: Morphallaxis from radiation biology to benzene toxicity

    International Nuclear Information System (INIS)

    Consensus principles from radiation biology were used to describe a generic set of nonlinear, first-order differential equations for modeling of toxicity-induced compensatory cell kinetics in terms of sublethal injury, repair, direct killing, killing of cells with unrepaired sublethal injury, and repopulation. This cellular model was linked to a probit model of hematopoietic mortality that describes death from infection and/or hemorrhage between ∼ 5 and 30 days. Mortality data from 27 experiments with 851 doseresponse groups, in which doses were protracted by rate and/or fractionation, were used to simultaneously estimate all rate constants by maximum-likelihood methods. Data used represented 18,940 test animals distributed according to: (mice, 12,827); (rats, 2,925); (sheep, 1,676); (swine, 829); (dogs, 479); and (burros, 204). Although a long-term, repopulating hematopoietic stem cell is ancestral to all lineages needed to restore normal homeostasis, the dose-response data from the protracted irradiations indicate clearly that the particular lineage that is ''critical'' to hematopoietic recovery does not resemble stem-like cells with regard to radiosensitivity and repopulation rates. Instead, the weakest link in the chain of hematopoiesis was found to have an intrinsic radioresistance equal to or greater than stromal cells and to repopulate at the same rates. Model validation has been achieved by predicting the LD50 and/or fractional group mortality in 38 protracted-dose experiments (rats and mice) that were not used in the fitting of model coefficients

  19. Population variability in biological adaptive responses to DNA damage and the shapes of carcinogen dose-response curves

    International Nuclear Information System (INIS)

    Carcinogen dose-response curves for both ionizing radiation and chemicals are typically assumed to be linear at environmentally relevant doses. This assumption is used to ensure protection of the public health in the absence of relevant dose-response data. A theoretical justification for the assumption has been provided by the argument that low dose linearity is expected when an exogenous agent adds to an ongoing endogenous process. Here, we use computational modeling to evaluate (1) how two biological adaptive processes, induction of DNA repair and cell cycle checkpoint control, may affect the shapes of dose-response curves for DNA-damaging carcinogens and (2) how the resulting dose-response behaviors may vary within a population. Each model incorporating an adaptive process was capable of generating not only monotonic dose-responses but also nonmonotonic (J-shaped) and threshold responses. Monte Carlo analysis suggested that all these dose-response behaviors could coexist within a population, as the spectrum of qualitative differences arose from quantitative changes in parameter values. While this analysis is largely theoretical, it suggests that (a) accurate prediction of the qualitative form of the dose-response requires a quantitative understanding of the mechanism (b) significant uncertainty is associated with human health risk prediction in the absence of such quantitative understanding and (c) a stronger experimental and regulatory focus on biological mechanisms and interindividual variability would allow flexibility in regulatory treatment of environmental carcinogens without compromising human health

  20. 车辆动载对路面的永久变形损伤评价%Evaluation of road permanent deformation damage due to vehicle dynamic load

    Institute of Scientific and Technical Information of China (English)

    张宗涛; 朱月风; 张洪亮

    2015-01-01

    T he rough pavement can impose dynamic load ,and the impact of dynamic load can increase the roughness of pavement surface ,this mutual promotion progress increases the road damage contin-uously ,so the study of the damage caused by vehicle dynamic load is of significance .As the main damage of pavement ,permanent deformation has larger influence on the road roughness and riding comfort .In this paper ,auto regressive(AR) model is used to simulate the random road excitation in time-domain ,and it is applied to the half-vehicle model for solving the vibration responses of vehicles on the rough pavement .Based on the fourth power theory ,a new evaluation index of road permanent deformation damage due to the vehicle dynamic load is put forward ,and this evaluation index is used to study the damage condition at different highway levels and speeds of vehicle .%不平整路面能够引起较大动荷载,动荷载的激励又使路面不平度增加,该互相促进过程使得路面破坏在不断加大,因此研究车辆动载对路面的损伤具有重要意义。永久变形作为路面的主要病害,对路面不平度和行车舒适性有较大影响。文章用自回归(auto regressive ,AR)模型模拟路面随机激励的时域模型,并应用在建立的1/2车辆模型中,求解汽车在不平整路面的振动响应量;根据“四次方定律”提出了车辆动载对路面永久变形损伤的评价指标,并在不同路面等级、不同车速等情况下研究车辆动载对路面永久变形损伤情况。

  1. Integration of principles of systems biology and radiation biology: toward development of in silico models to optimize IUdR-mediated radiosensitization of DNA mismatch repair-deficient (damage tolerant human cancers

    Directory of Open Access Journals (Sweden)

    Timothy James Kinsella

    2011-08-01

    Full Text Available Over the last 7 years, we have focused our experimental and computational research efforts on improving our understanding of the biochemical, molecular, and cellular processing of iododeoxyuridine (IUdR and ionizing radiation (IR induced DNA base damage by DNA mismatch repair (MMR. These coordinated research efforts, sponsored by the National Cancer Institute Integrative Cancer Biology Program (ICBP, brought together system scientists with expertise in engineering, mathematics, and complex systems theory and translational cancer researchers with expertise in radiation biology. Our overall goal was to begin to develop computational models of IUdR- and/or IR- induced base damage processing by MMR that may provide new clinical strategies to optimize IUdR-mediated radiosensitiztion in MMR deficient (MMR- damage tolerant human cancers. Using multiple scales of experimental testing, ranging from purified protein systems to in vitro (cellular and to in vivo (human tumor xenografts in athymic mice models, we have begun to integrate and interpolate these experimental data with hybrid stochastic biochemical models of MMR damage processing and probabilistic cell cycle regulation models through a systems biology approach. In this article, we highlight the results and current status of our integration of radiation biology approaches and computational modeling to enhance IUdR-mediated radiosensitization in MMR- damage tolerant cancers.

  2. Serratia Secondary Metabolite Prodigiosin Inhibits Pseudomonas aeruginosa Biofilm Development by Producing Reactive Oxygen Species that Damage Biological Molecules

    Science.gov (United States)

    Kimyon, Önder; Das, Theerthankar; Ibugo, Amaye I.; Kutty, Samuel K.; Ho, Kitty K.; Tebben, Jan; Kumar, Naresh; Manefield, Mike

    2016-01-01

    Prodigiosin is a heterocyclic bacterial secondary metabolite belonging to the class of tripyrrole compounds, synthesized by various types of bacteria including Serratia species. Prodigiosin has been the subject of intense research over the last decade for its ability to induce apoptosis in several cancer cell lines. Reports suggest that prodigiosin promotes oxidative damage to double-stranded DNA (dsDNA) in the presence of copper ions and consequently leads to inhibition of cell-cycle progression and cell death. However, prodigiosin has not been previously implicated in biofilm inhibition. In this study, the link between prodigiosin and biofilm inhibition through the production of redox active metabolites is presented. Our study showed that prodigiosin (500 μM) (extracted from Serratia marcescens culture) and a prodigiosin/copper(II) (100 μM each) complex have strong RNA and dsDNA cleaving properties while they have no pronounced effect on protein. Results support a role for oxidative damage to biomolecules by H2O2 and hydroxyl radical generation. Further, it was demonstrated that reactive oxygen species scavengers significantly reduced the DNA and RNA cleaving property of prodigiosin. P. aeruginosa cell surface hydrophobicity and biofilm integrity were significantly altered due to the cleavage of nucleic acids by prodigiosin or the prodigiosin/copper(II) complex. In addition, prodigiosin also facilitated the bactericidal activity. The ability of prodigiosinto cause nucleic acid degradation offers novel opportunities to interfere with extracellular DNA dependent bacterial biofilms. PMID:27446013

  3. Serratia secondary metabolite prodigiosin inhibit Pseudomonas aeruginosa biofilm development by producing reactive oxygen species that damage biological molecules.

    Directory of Open Access Journals (Sweden)

    Onder eKimyon

    2016-06-01

    Full Text Available Prodigiosin is a heterocyclic bacterial secondary metabolite belonging to the class of tripyrrole compounds, synthesized by various types of bacteria including Serratia species. Prodigiosin has been the subject of intense research over the last decade for its ability to induce apoptosis in several cancer cell lines. Reports suggest that prodigiosin promotes oxidative damage to double-stranded DNA (dsDNA in the presence of copper ions and consequently leads to inhibition of cell-cycle progression and cell death. However, prodigiosin has not been previously implicated in biofilm inhibition. In this study, the link between prodigiosin and biofilm inhibition through the production of redox active metabolites is presented. Our study showed that prodigiosin (500 µM (extracted from Serratia marcescens culture and a prodigiosin/copper(II (100 µM each complex have strong RNA and dsDNA cleaving properties while they have no pronounced effect on protein. Results support a role for oxidative damage to biomolecules by H2O2 and hydroxyl radical generation. Further, it was demonstrated that reactive oxygen species scavengers significantly reduced the DNA and RNA cleaving property of prodigiosin. P. aeruginosa cell surface hydrophobicity and biofilm integrity were significantly altered due to the cleavage of nucleic acids by prodigiosin or the prodigiosin/copper(II complex. In addition, prodigiosin also facilitated the bactericidal activity. The ability of prodigiosin to cause nucleic acid degradation offers novel opportunities to interfere with extracellular DNA dependent bacterial biofilms.

  4. [The specific features of the damage to the non-biological and biological simulators of the human body inflicted by the shots from a 9.0 mm pneumatic rifle].

    Science.gov (United States)

    Raizberg, S A; Makarov, L Iu; Lorents, A S

    2015-01-01

    The objective of the present work was to study the specific constructional features of a 9.0 mm pneumatic rifle designed to use three types of bullets differing in the head shape. Also, the morphological signs of the injuries inflicted by such bullets that can serve as the prerequisites for objective differentiation of the damages are considered. The study revealed peculiarities of experimental damage to the non-biological (plasticine blocks) and biological (bio-mannequins) simulators of homogeneous human tissues inflicted by the shots from the pneumatic rifle from different distances. PMID:26036065

  5. Evolutionary malignant resistance of cells to damaging factors as common biological defence mechanism in neoplastic development. Review of conception.

    Science.gov (United States)

    Monceviciute-Eringiene, E

    2000-09-01

    Cells have some inborn resistance to harmful factors, which could be called physiological or natural resistance. The mechanisms of multixenobiotic resistance (MXR) and multidrug resistance (MDR) have common features in the formation of acquired resistance in microorganisms, carcinogenesis, tumour metastases and chemotherapy or irradiation. ATP-dependent membrane P-glycoprotein, as an MDR efflux pump, glutathione S-transferases and other products of evolutionary resistance-related genes arised for exportation and detoxification of cytotoxic xenobiotics and drugs are transmitted from bacteria to man. On the one hand, this evolutionary MXR as a common biological defence mechanism is a "driving" power to conserve homeostasis of cells, tissues and organs. On the other hand, mutation, selection and simplification of properties are the causes of functional and morphological changes in tumour cells which regress to a more primitive mode of existence (atavism) for adaptation to survival. In the present work are presented data on the forms of E. coli resistant to antibiotics and of sarcoma 45 resistant to alkylic preparations. They may be helpful in revealing the causes of resistance and acquired accelerated growth of cells. The development of tumours as fibromas 14-15 years following injection of a vital dye trypan blue into human skin supports our conception that neoplastic growth is a particular case of the evolutionary resistance of cells adapted to the damaging factors. So, tumour cells adopting the enhancement mechanisms of general biological persistent resistance, i. e. undergoing repeated cycles of malignancy enhancement, adapt themselves to survive under the changed unfavourable conditions. PMID:11144527

  6. The Biological Effectiveness of Four Energies of Neon Ions for the Induction of Chromosome Damage in Human Lymphocytes

    Science.gov (United States)

    George, Kerry; Hada, Megumi; Cucinotta, F. A.

    2011-01-01

    Chromosomal aberrations were measured in human peripheral blood lymphocytes after in vitro exposure to neon ions at energies of 64, 89, 142, or 267. The corresponding LET values for these energies of neon ranged from 38-103 keV/micrometers and doses delivered were in the 10 to 80 cGy range. Chromosome exchanges were assessed in metaphase and G2 phase cells at first division after exposure using fluorescence in situ hybridization (FISH) with whole chromosome probes and dose response curves were generated for different types of chromosomal exchanges. The yields of total chromosome exchanges were similar for the 64, 89, and 142 MeV exposures, whereas the 267 MeV/u neon with LET of 38 keV/micrometers produced about half as many exchanges per unit dose. The induction of complex type chromosome exchanges (exchanges involving three or more breaks and two or more chromosomes) showed a clear LET dependence for all energies. The ratio of simple to complex type exchanges increased with LET from 18 to 51%. The relative biological effectiveness (RBE) was estimated from the initial slope of the dose response curve for chromosome damage with respect to gamma-rays. The RBE(sub max) values for total chromosome exchanges for the 64 MeV/u was around 30.

  7. Nanoscale analysis of unstained biological specimens in water without radiation damage using high-resolution frequency transmission electric-field system based on FE-SEM.

    Science.gov (United States)

    Ogura, Toshihiko

    2015-04-10

    Scanning electron microscopy (SEM) has been widely used to examine biological specimens of bacteria, viruses and proteins. Until now, atmospheric and/or wet biological specimens have been examined using various atmospheric holders or special equipment involving SEM. Unfortunately, they undergo heavy radiation damage by the direct electron beam. In addition, images of unstained biological samples in water yield poor contrast. We recently developed a new analytical technology involving a frequency transmission electric-field (FTE) method based on thermionic SEM. This method is suitable for high-contrast imaging of unstained biological specimens. Our aim was to optimise the method. Here we describe a high-resolution FTE system based on field-emission SEM; it allows for imaging and nanoscale examination of various biological specimens in water without radiation damage. The spatial resolution is 8 nm, which is higher than 41 nm of the existing FTE system. Our new method can be easily utilised for examination of unstained biological specimens including bacteria, viruses and protein complexes. Furthermore, our high-resolution FTE system can be used for diverse liquid samples across a broad range of scientific fields, e.g. nanoparticles, nanotubes and organic and catalytic materials.

  8. Application of a molecular biology concept for the detection of DNA damage and repair during UV disinfection.

    Science.gov (United States)

    Süss, Jacqueline; Volz, Sabrina; Obst, Ursula; Schwartz, Thomas

    2009-08-01

    As nucleic acids are major targets in bacteria during standardised UV disinfection (254 nm), inactivation rates also depend on bacterial DNA repair. Due to UV-related DNA modifications, PCR-based approaches allow for a direct detection of DNA damage and repair during UV disinfection. By applying different primer sets, the correlation between amplicon length and PCR amplification became obvious. The longer the targeted DNA fragment was, the more UV-induced DNA lesions inhibited the PCR. Regeneration of Pseudomonas aeruginosa, Enterococcus faecium, and complex wastewater communities was recorded over a time period of 66 h. While phases of intensive repair and proliferation were found for P. aeruginosa, no DNA repair was detected by qPCR in E. faecium. Cultivation experiments verified these results. Despite high UV mediated inactivation rates original wastewater bacteria seem to express an enhanced robustness against irradiation. Regeneration of dominant and proliferation of low-abundant, probably UV-resistant species contributed to a strong post-irradiation recovery accompanied by a selection for beta-Proteobacteria.

  9. Damage, biology and natural enemies of the green oak moth, [Tortrix viridana L. 1758 (Lep.; Tortricidae)] in Dinar district oak forests

    OpenAIRE

    Tuncer, İsmail; Avcı, Mustafa

    2015-01-01

    In this study, the distribution of Tortrix viridana in Dinar region, its damage to the host plant stands as well as its biology and natural enemies were explored. Samples were examined and collected in the research area periodically from 2012 to 2014. The harmful insects were found on three oak species in the research area. They were Quercus coccifera, Q. infectoria and Q. pubescens. It was observed that adult insect emergence started in late May and continued decreasingly in June. It was als...

  10. Changes in biological markers, particularly hormone receptors, due to pre-operative chemotherapy (epirubicin/docetaxel in operable breast cancer

    Directory of Open Access Journals (Sweden)

    Rumiko Tashima

    2011-12-01

    Full Text Available We investigated the correlation between biological markers prior to pre-operative chemotherapy with epirubicin and docetaxel (ET therapy and the effect of treatment as well as the clinically significant changes in biological markers before and after chemotherapy. Since April 2002, 52 patients with tumors ≥3 cm in diameter or lymph node metastases have received pre-operative ET chemotherapy. The items investigated were ER/PgR, proliferative activity (MIB-1, etc. The correlation of changes in these factors between pre- and post-treatment status and the clinical and pathological responses was investigated. Clinical response was 82%, BCS rate was 67%. Pathological response was 31.4%. The ER/PgR positive cell rate significantly decreased from 48%/32% to 37%/14%. The MIB-1 decreased from 48% to 27%. The pathological response was significantly high in patients with low ER/PgR-positive rates and those with high MIB-1 values.

  11. Study on vibration fatigue damage due to the blow of OPGW aluminum tube; OPGW aluminium kan no kyofu ni yoru shindo hiro hason ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Aikawa, S.; Kohara, H. [Chugoku Electric Power Co. Inc., Hiroshima (Japan)

    2000-03-24

    The cause of damage in the cashing portion of an aluminum tube incorporating OPGW (OPAC 120mm{sup 2}) was investigated and proper measures for the prevention of recurrence were examined. The investigation result of the past accident of the same kind or the result of stress measurement showed that the cause of aluminum tube damage is the fatigue rupture based on the repeated stress occurring by the rolling of OPGW. Moreover, it was known that the attached wire in a jumper lead-in system is most effective and valid as preventative measures of damage. (translated by NEDO)

  12. Amelioration of oxidative DNA damage in mouse peritoneal macrophages by Hippophae salicifolia due to its proton (H+) donation capability: Ex vivo and in vivo studies

    OpenAIRE

    Mainak Chakraborty; Indrajit Karmakar; Sagnik Haldar; Avratanu Das; Asis Bala; Pallab Kanti Haldar

    2016-01-01

    Introduction: The present study evaluates the antioxidant effect of methanol extract of Hippophae salicifolia (MEHS) bark with special emphasis on its role on oxidative DNA damage in mouse peritoneal macrophages. Material and Methods: In vitro antioxidant activity was estimated by standard antioxidant assays whereas the antioxidant activity concluded the H+ donating capacity. Mouse erythrocytes' hemolysis and peritoneal macrophages' DNA damage were determined spectrophotometrically. In vivo a...

  13. Amelioration of oxidative DNA damage in mouse peritoneal macrophages by Hippophae salicifolia due to its proton (H+) donation capability: Ex vivo and in vivo studies

    OpenAIRE

    Chakraborty, Mainak; Karmakar, Indrajit; Haldar, Sagnik; Das, Avratanu; Bala, Asis; Haldar, Pallab Kanti

    2016-01-01

    Introduction: The present study evaluates the antioxidant effect of methanol extract of Hippophae salicifolia (MEHS) bark with special emphasis on its role on oxidative DNA damage in mouse peritoneal macrophages. Material and Methods: In vitro antioxidant activity was estimated by standard antioxidant assays whereas the antioxidant activity concluded the H+ donating capacity. Mouse erythrocytes’ hemolysis and peritoneal macrophages’ DNA damage were determined spectrophotometrically. In vivo a...

  14. Radiation damage and repair in cells and cell components. Part 2. Physical radiations and biological significance. Final report

    International Nuclear Information System (INIS)

    The report comprises a teaching text, encompassing all physical radiations likely to be of biological interest, and the relevant biological effects and their significance. Topics include human radiobiology, delayed effects, radiation absorption in organisms, aqueous radiation chemistry, cell radiobiology, mutagenesis, and photobiology

  15. Biological function and regulation of histone and non-histone lysine methylation in response to DNA damage.

    Science.gov (United States)

    Chen, Yongcan; Zhu, Wei-Guo

    2016-07-01

    DNA damage response (DDR) signaling network is initiated to protect cells from various exogenous and endogenous damage resources. Timely and accurate regulation of DDR proteins is required for distinct DNA damage repair pathways. Post-translational modifications of histone and non-histone proteins play a vital role in the DDR factor foci formation and signaling pathway. Phosphorylation, ubiquitylation, SUMOylation, neddylation, poly(ADP-ribosyl)ation, acetylation, and methylation are all involved in the spatial-temporal regulation of DDR, among which phosphorylation and ubiquitylation are well studied. Studies in the past decade also revealed extensive roles of lysine methylation in response to DNA damage. Lysine methylation is finely regulated by plenty of lysine methyltransferases, lysine demethylases, and can be recognized by proteins with chromodomain, plant homeodomain, Tudor domain, malignant brain tumor domain, or proline-tryptophan-tryptophan-proline domain. In this review, we outline the dynamics and regulation of histone lysine methylation at canonical (H3K4, H3K9, H3K27, H3K36, H3K79, and H4K20) and non-canonical sites after DNA damage, and discuss their context-specific functions in DDR protein recruitment or extraction, chromatin environment establishment, and transcriptional regulation. We also present the emerging advances of lysine methylation in non-histone proteins during DDR. PMID:27217472

  16. Biological function and regulation of histone and non-histone lysine methylation in response to DNA damage

    Institute of Scientific and Technical Information of China (English)

    Yongcan Chen; Wei-Guo Zhu

    2016-01-01

    DNA damage response (DDR) signaling network is initiated to protect cells from various exogenous and endogenous damage resources.Timely and accurate regulation of DDR proteins is required for distinct DNA damage repair pathways.Post-translational modifications of histone and non-histone proteins play a vital role in the DDR factor foci formation and signaling pathway.Phosphorylation,ubiquitylation,SUMOylation,neddylation,poly(ADP-ribosyl)ation,acetylation,and methylation are all involved in the spatial-temporal regulation of DDR,among which phosphorylation and ubiquitylation are well studied.Studies in the past decade also revealed extensive roles of lysine methylation in response to DNA damage.Lysine methylation is finely regulated by plenty of lysine methyltransferases,lysine demethylases,and can be recognized by proteins with chromodomain,plant homeodomain,Tudor domain,malignant brain tumor domain,or prolinetryptophan-tryptophan-proline domain.In this review,we outline the dynamics and regulation of histone lysine methylation at canonical (H3K4,H3K9,H3K27,H3K36,H3K79,and H4K20) and non-canonical sites after DNA damage,and discuss their context-specific functions in DDR protein recruitment or extraction,chromatin environment establishment,and transcriptional regulation.We also present the emerging advances of lysine methylation in non-histone proteins during DDR.

  17. MRI findings of brain damage due to neonatal hypoglycemia%新生儿低血糖脑损伤的MRI表现

    Institute of Scientific and Technical Information of China (English)

    王璐; 范国光; 冀旭; 孙宝海; 郭启勇

    2009-01-01

    Objective To report the MRI findings of brain damage obsenrved in neonatal patients who suffered from isolated hypoglycemia and to explore the value of diffusion-weighted imaging(DWI) inearly detection of neonatal hypoglycemic brain iniun,. Methods Twelve neonates with isolated hypoglycemia(10 of the 12 were diagnosed to suffer from hypoglycemic encephalopathy)were enrolled in this study.They were first scanned at age from 3 days to 10 days with Tl WI,T,WI and DWI(b is 0 s/mm2,1000 s/mm2),and 4 of them were then scanned from 7 days to 10 days following the initial scan.All acquired MR images were retrospectively analysed.Results First series of DWl images showed distinct hyperintense signal in 11 cases in several areas including bi lateral occipital cortex(2 cases),right occipital cortex(1 case),left occipital cortex and subcortical white matter(1 case),biIateral occipital cortex and flubcortical white matter(2 cases),bilateral parieto-occipital cortex(2 cases),bilateral parieto-occipital cortex and subcortical white matter(2 cases),the splenium of corpus catlosum(4 cases),bilateral corona radiata(2 cases),left eaudate nucleus and globus pallidus(1 case),bilateral thalamus(1 case),bilaterally posterior limb of internal capsule(1 ease).In the initial T1 WI and T2,WI images,there were subtle hypointensity in the damaged cortical areas(3 cases),hyperintensity in the bilaterally affected occipital cortex(1 case)on T1 weighted images,and hyperintensity in the affected cortex and subcortieal white matter with poor differentiation on T2 weighted images.The followed-up MRI of 4 cases showed regional encephalomalaeia in the affected occipital lobes(4 cases),slightly hyperintensity on T2 weighted images in the damaged occipital cortex(2 cases),extensive demyelination(1 case).disappearance of hyperintensity of the splenium of corpus callosum(1 case),and persistent hyperintensity in the splenium of corpus callosum (1 case)on T2 weighted images.Conclusion The findings suggest

  18. Biologic

    CERN Document Server

    Kauffman, L H

    2002-01-01

    In this paper we explore the boundary between biology and the study of formal systems (logic). In the end, we arrive at a summary formalism, a chapter in "boundary mathematics" where there are not only containers but also extainers ><, entities open to interaction and distinguishing the space that they are not. The boundary algebra of containers and extainers is to biologic what boolean algebra is to classical logic. We show how this formalism encompasses significant parts of the logic of DNA replication, the Dirac formalism for quantum mechanics, formalisms for protein folding and the basic structure of the Temperley Lieb algebra at the foundations of topological invariants of knots and links.

  19. Effects of the feeding of wild Yeso sika deer (Cervus nippon yesoensis) on the prevention of damage due to bark stripping and the use of feeding sites.

    Science.gov (United States)

    Masuko, Takayoshi; Souma, Kousaku; Kudo, Hirofumi; Takasaki, Yukari; Fukui, Emi; Kitazawa, Reiko; Nishida, Rikihiro; Niida, Toshimitsu; Suzuki, Teiji; Nibe, Akio

    2011-08-01

    Feeding sites for wild Yeso sika deer around Lake Akan, Japan, were established. Effects on the number of deer using the feeding sites, the prevention of bark stripping damage, the amount of feeding, and eating time in a 5-year period (1999-2003) were evaluated. The number of deer using feeding sites increased with years during the feeding period. The damaged tree ratio after the initiation of feeding markedly decreased compared with 16.5% before the initiation of feeding. After the start of feeding, there were no trees with damage the entire circumference. According to tree species, the number of damaged trees of Ulmus laciniata Mayr as a percentage of all investigated trees was high (5.2%). The total amount of beet pulp feeding increased with the feeding year, showing 4.5-fold increase. At feeding sites in deer culling, eating behavior was observed during the night. The preventive effects on bark stripping damage continued during the 5-year feeding period. However, with the course of feeding years, the number of deer using feeding sites and the level of feeding increased. PMID:21794018

  20. NASA space cancer risk model-2014: Uncertainties due to qualitative differences in biological effects of HZE particles

    Science.gov (United States)

    Cucinotta, Francis

    Uncertainties in estimating health risks from exposures to galactic cosmic rays (GCR) — comprised of protons and high-energy and charge (HZE) nuclei are an important limitation to long duration space travel. HZE nuclei produce both qualitative and quantitative differences in biological effects compared to terrestrial radiation leading to large uncertainties in predicting risks to humans. Our NASA Space Cancer Risk Model-2012 (NSCR-2012) for estimating lifetime cancer risks from space radiation included several new features compared to earlier models from the National Council on Radiation Protection and Measurements (NCRP) used at NASA. New features of NSCR-2012 included the introduction of NASA defined radiation quality factors based on track structure concepts, a Bayesian analysis of the dose and dose-rate reduction effectiveness factor (DDREF) and its uncertainty, and the use of a never-smoker population to represent astronauts. However, NSCR-2012 did not include estimates of the role of qualitative differences between HZE particles and low LET radiation. In this report we discuss evidence for non-targeted effects increasing cancer risks at space relevant HZE particle absorbed doses in tissue (Mars exploration will be described, and compared to those of our earlier NSCR-2012 model.

  1. Gain of Cellular Adaptation Due to Prolonged p53 Impairment Leads to Functional Switchover from p53 to p73 during DNA Damage in Acute Myeloid Leukemia Cells*

    OpenAIRE

    Chakraborty, Juni; Banerjee, Shuvomoy; Ray, Pallab; Hossain, Dewan Md Sakib; Bhattacharyya, Sankar; Adhikary, Arghya; Chattopadhyay, Sreya; Das, Tanya; Sa, Gaurisankar

    2010-01-01

    Tumor suppressor p53 plays the central role in regulating apoptosis in response to genotoxic stress. From an evolutionary perspective, the activity of p53 has to be backed up by other protein(s) in case of any functional impairment of this protein, to trigger DNA damage-induced apoptosis in cancer cells. We adopted multiple experimental approaches to demonstrate that in p53-impaired cancer cells, DNA damage caused accumulation of p53 paralogue p73 via Chk-1 that strongly impacted Bax expressi...

  2. I. Federal Order of 18 December 1987 and II. Ordinance of 13 April 1988 on compensation from the Confederation to persons having suffered damage due to the Chernobyl catastrophe

    International Nuclear Information System (INIS)

    The Order and Ordinance provide for the indemnification by the State of farmers, herb-growers, market-gardeners and fishermen in Lake Lugano for economic damage suffered due to the Chernobyl accident. Both entered into force on 15 April 1988. (NEA)

  3. Variability of projected terrestrial biosphere responses to elevated levels of atmospheric CO2 due to uncertainty in biological nitrogen fixation

    Science.gov (United States)

    Meyerholt, Johannes; Zaehle, Sönke; Smith, Matthew J.

    2016-03-01

    Including a terrestrial nitrogen (N) cycle in Earth system models has led to substantial attenuation of predicted biosphere-climate feedbacks. However, the magnitude of this attenuation remains uncertain. A particularly important but highly uncertain process is biological nitrogen fixation (BNF), which is the largest natural input of N to land ecosystems globally. In order to quantify this uncertainty and estimate likely effects on terrestrial biosphere dynamics, we applied six alternative formulations of BNF spanning the range of process formulations in current state-of-the-art biosphere models within a common framework, the O-CN model: a global map of static BNF rates, two empirical relationships between BNF and other ecosystem variables (net primary productivity and evapotranspiration), two process-oriented formulations based on plant N status, and an optimality-based approach. We examined the resulting differences in model predictions under ambient and elevated atmospheric [CO2] and found that the predicted global BNF rates and their spatial distribution for contemporary conditions were broadly comparable, ranging from 108 to 148 Tg N yr-1 (median: 128 Tg N yr-1), despite distinct regional patterns associated with the assumptions of each approach. Notwithstanding, model responses in BNF rates to elevated levels of atmospheric [CO2] (+200 ppm) ranged between -4 Tg N yr-1 (-3 %) and 56 Tg N yr-1 (+42 %) (median: 7 Tg N yr-1 (+8 %)). As a consequence, future projections of global ecosystem carbon (C) storage (+281 to +353 Pg C, or +13 to +16 %) as well as N2O emission (-1.6 to +0.5 Tg N yr-1, or -19 to +7 %) differed significantly across the different model formulations. Our results emphasize the importance of better understanding the nature and magnitude of BNF responses to change-induced perturbations, particularly through new empirical perturbation experiments and improved model representation.

  4. Differential biologic effects of CPD and 6-4PP UV-induced DNA damage on the induction of apoptosis and cell-cycle arrest

    Directory of Open Access Journals (Sweden)

    Yasui Akira

    2005-10-01

    Full Text Available Abstract Background UV-induced damage can induce apoptosis or trigger DNA repair mechanisms. Minor DNA damage is thought to halt the cell cycle to allow effective repair, while more severe damage can induce an apoptotic program. Of the two major types of UV-induced DNA lesions, it has been reported that repair of CPD, but not 6-4PP, abrogates mutation. To address whether the two major forms of UV-induced DNA damage, can induce differential biological effects, NER-deficient cells containing either CPD photolyase or 6-4 PP photolyase were exposed to UV and examined for alterations in cell cycle and apoptosis. In addition, pTpT, a molecular mimic of CPD was tested in vitro and in vivo for the ability to induce cell death and cell cycle alterations. Methods NER-deficient XPA cells were stably transfected with CPD-photolyase or 6-4PP photolyase to specifically repair only CPD or only 6-4PP. After 300 J/m2 UVB exposure photoreactivation light (PR, UVA 60 kJ/m2 was provided for photolyase activation and DNA repair. Apoptosis was monitored 24 hours later by flow cytometric analysis of DNA content, using sub-G1 staining to indicate apoptotic cells. To confirm the effects observed with CPD lesions, the molecular mimic of CPD, pTpT, was also tested in vitro and in vivo for its effect on cell cycle and apoptosis. Results The specific repair of 6-4PP lesions after UVB exposure resulted in a dramatic reduction in apoptosis. These findings suggested that 6-4PP lesions may be the primary inducer of UVB-induced apoptosis. Repair of CPD lesions (despite their relative abundance in the UV-damaged cell had little effect on the induction of apoptosis. Supporting these findings, the molecular mimic of CPD, (dinucleotide pTpT could mimic the effects of UVB on cell cycle arrest, but were ineffective to induce apoptosis. Conclusion The primary response of the cell to UV-induced 6-4PP lesions is to trigger an apoptotic program whereas the response of the cell to CPD

  5. Biologically relevant oxidants and terminology, classification and nomenclature of oxidatively generated damage to nucleobases and 2-deoxyribose in nucleic acids

    DEFF Research Database (Denmark)

    Cadet, Jean; Loft, Steffen; Olinski, Ryszard;

    2012-01-01

    A broad scientific community is involved in investigations aimed at delineating the mechanisms of formation and cellular processing of oxidatively generated damage to nucleic acids. Perhaps as a consequence of this breadth of research expertise, there are nomenclature problems for several...... on the main oxidative radicals, non-radical oxygen species, one-electron agents and enzymes involved in DNA degradation pathways as well in their targets and reactivity. A brief classification of oxidatively generated damage to DNA that may involve single modifications, tandem base modifications, intrastrand...... and interstrand cross-links together with DNA-protein cross-links and base adducts arising from the addition of lipid peroxides breakdown products is also included....

  6. Biological control of the spruce coneworm Dioryctria abietella: Spraying with Bacillus thuringiensis reduced damage in a seed orchard

    Energy Technology Data Exchange (ETDEWEB)

    Weslien, Jan [Forestry Research Inst. of Sweden, Uppsala (Sweden)

    1999-08-01

    Spraying of cones with Bacillus thuringiensis var. Kurstaki x Aizawa in a Norway spruce (Picea abies (L.) Karst.) seed orchard reduced damage by Dioryctria abietella Den. et Schiff. (Lepidoptera, Pyralidae). The incidence of D. abietella attacks was about 80% among unsprayed cones, but less than 15% showed attacks among cones that had been sprayed three times at 9-day intervals with a 0.2% suspension (weight/weight) of the B. thuringiensis preparation in water (Turex 50 WP, 25 000 IU/mg). Attacked, sprayed cones had fewer D. abietella larvae per cone than attacked, unsprayed cones. Spraying did not reduce the damage by Cydia strobilella (L.) (Lepidoptera, Tortricidae) or by Strobilomyia anthracina Czerny (Diptera, Anthomyiidae) 13 refs, 3 tabs

  7. Choice of Cell Source in Cell-Based Therapies for Retinal Damage due to Age-Related Macular Degeneration: A Review

    Directory of Open Access Journals (Sweden)

    Sudhakar John

    2013-01-01

    Full Text Available Background. Age-related macular degeneration (AMD is a complex disorder that affects primarily the macula involving the retinal pigment epithelium (RPE but also to a certain extent the photoreceptor layer and the retinal neurons. Cell transplantation is a promising option for AMD and clinical trials are underway using different cell types. Methods. We hypothesize that instead of focusing on a particular cell source for concurrent regeneration of all the retinal layers and also to prevent exhaustive research on an array of cell sources for regeneration of each layer, the choice should depend on, precisely, which layer is damaged. Results. Thus, for a damage limited to the retinal pigment epithelial (RPE layer, the choice we suggest would be RPE cells. When the damage extends to rods and cones, the choice would be bone marrow stem cells and when retinal neurons are involved, relatively immature stem cell populations with an inherent capacity to yield neuronal lineage such as hematopoietic stem cells, embryonic stem cells, or induced pluripotent stem cells can be tried. Conclusion. This short review will prove to be a valuable guideline for those working on cell therapy for AMD to plan their future directions of research and therapy for this condition.

  8. Damage due to Hanshin-Awaji Earthquake and related subsurface conditions in Toyonaka City; Hanshin/Awaji Daishinsai ni okeru Toyonakashi no higai to jiban

    Energy Technology Data Exchange (ETDEWEB)

    Shinozaki, W.; Tanimura, K. [Construction Project Consultant Co. Ltd., Osaka (Japan); Takada, N. [Osaka City Univ., Osaka (Japan). Faculty of Engineering

    1996-02-01

    In spite of the fact that Toyonaka City in Osaka Prefecture is away from the seismic center by about 50 km, the number of houses completely or partially destroyed was as large as 10,000, and a maximum of about 3000 people had lived refuge lives. Toyonaka City topographically comprises an alluvial plain on the south of the Sone terraced cliff extending from east to west in the central part of the same city, and the undulating Senri hills on the north of the terraced cliff. In the substantially whole area of the alluvial plain, the wooden houses and some medium-storied ferro-concrete buildings were damaged, and, in the western inclined part of the hilly area, houses and housing lands were suffered from the earthquake. Underground buried facilities, such as waterworks and sewage were also damaged in substantially the same areas in which houses were destructed. This paper summarizes the relation between the distribution of seismic destruction and the ground and topographical conditions, correlating the results of the investigation into the earthquake disaster which was conducted by Toyonaka City with the ground diagram of the same city. It is considered that the damage by the earthquake was enlarged by not only the weak alluvial layers and loose fill-up ground but also the seismic motion amplified by the generally called `waterside focusing effect` of the hills extending toward the seismic center. 3 refs., 4 figs., 1 tab.

  9. Systems Biology Model of Interactions Between Tissue Growth Factors and DNA Damage Pathways: Low Dose Response and Cross-Talk in TGFbeta and ATM Signaling

    Energy Technology Data Exchange (ETDEWEB)

    O' Neill, Peter [University of Oxford; Anderson, Jennifer [University of Oxford

    2014-10-02

    The etiology of radiation carcinogenesis has been described in terms of aberrant changes that span several levels of biological organization. Growth factors regulate many important cellular and tissue functions including apoptosis, differentiation and proliferation. A variety of genetic and epigenetic changes of growth factors have been shown to contribute to cancer initiation and progression. It is known that cellular and tissue damage to ionizing radiation is in part initiated by the production of reactive oxygen species, which can activate cytokine signaling, and the DNA damage response pathways, most notably the ATM signaling pathway. Recently the transforming growth factor β (TGFβ) pathway has been shown to regulate or directly interact with the ATM pathway in the response to radiation. The relevance of this interaction with the ATM pathway is not known although p53 becomes phosphorylated and DNA damage responses are involved. However, growth factor interactions with DNA damage responses have not been elucidated particularly at low doses and further characterization of their relationship to cancer processes is warranted. Our goal will be to use a systems biology approach to mathematically and experimentally describe the low dose responses and cross-talk between the ATM and TGFβ pathways initiated by low and high LET radiation. We will characterize ATM and TGFβ signaling in epithelial and fibroblast cells using 2D models and ultimately extending to 3D organotypic cell culture models to begin to elucidate possible differences that may occur for different cell types and/or inter-cellular communication. We will investigate the roles of the Smad and Activating transcription factor 2 (ATF2) proteins as the potential major contributors to cross- talk between the TGFβ and ATM pathways, and links to cell cycle control and/or the DNA damage response, and potential differences in their responses at low and high doses. We have developed various experimental

  10. Air exposure behavior of the semiterrestrial crab Neohelice granulata allows tolerance to severe hypoxia but not prevent oxidative damage due to hypoxia-reoxygenation cycle.

    Science.gov (United States)

    de Lima, Tábata Martins; Geihs, Márcio Alberto; Nery, Luiz Eduardo Maia; Maciel, Fábio Everton

    2015-11-01

    The air exposure behavior of the semi-terrestrial crab Neohelice granulata during severe hypoxia was studied. This study also verified whether this behavior mitigates possible oxidative damage, namely lipoperoxidation, caused by hypoxia and reoxygenation cycles. The lethal time for 50% of the crabs subjected to severe hypoxia (0.5 mgO2 · L(-1)) with free access to air was compared to that of crabs subjected to severe hypoxia without access to air. Crabs were placed in aquaria divided into three zones: water (when the animal was fully submersed), land (when the animal was completely emerged) and intermediate (when the animal was in contact with both environments) zones. Then the crabs were held in this condition for 270 min, and the time spent in each zone was recorded. Lipid peroxidation (LPO) damage to the walking leg muscles was determined for the following four experimental conditions: a--normoxic water with free access to air; b--hypoxic water without access to air; c--hypoxic water followed by normoxic water without air access; and d--hypoxic water with free access to air. When exposed to hypoxic water, N. granulata spent significantly more time on land, 135.3 ± 17.7 min, whereas control animals (exposed to normoxic water) spent more time submerged, 187.4 ± 20.2 min. By this behavior, N. granulata was able to maintain a 100% survival rate when exposed to severe hypoxia. However, N. granulata must still return to water after periods of air exposure (~ 14 min), causing a sequence of hypoxia/reoxygenation events. Despite increasing the survival rate, hypoxia with air access does not decrease the lipid peroxidation damage caused by the hypoxia and reoxygenation cycle experienced by these crabs.

  11. Scenario-based assessment of buildings' damage and population exposure due to earthquake-induced tsunamis for the town of Alexandria, Egypt

    Science.gov (United States)

    Pagnoni, G.; Armigliato, A.; Tinti, S.

    2015-12-01

    Alexandria is the second biggest city in Egypt with regards to population, is a key economic area in northern Africa and has very important tourist activity. Historical records indicate that it was severely affected by a number of tsunami events. In this work we assess the tsunami hazard by running numerical simulations of tsunami impact in Alexandria through the worst-case credible tsunami scenario analysis (WCTSA). We identify three main seismic sources: the western Hellenic Arc (WHA - reference event AD 365, Mw = 8.5), the eastern Hellenic Arc (EHA - reference event 1303, Mw = 8.0) and the Cyprus Arc (CA - hypothetical scenario earthquake with Mw = 8.0), inferred from the tectonic setting and from historical tsunami catalogues. All numerical simulations are carried out in two sea level conditions (mean sea level and maximum high-tide sea level) by means of the code UBO-TSUFD, developed and maintained by the Tsunami Research Team of the University of Bologna. Relevant tsunami metrics are computed for each scenario and then used to build aggregated fields such as the maximum flood depth and the maximum inundation area. We find that the case that produces the most relevant flooding in Alexandria is the EHA scenario, with wave heights up to 4 m. The aggregate fields are used for a building vulnerability assessment according to a methodology developed in the framework of the EU-FP6 project SCHEMA and further refined in this study, based on the adoption of a suitable building damage matrix and on water inundation depth. It is found that in the districts of El Dekhila and Al Amriyah, to the south-west of the port of Dekhila, over 12 000 (13 400 in the case of maximum high tide) buildings could be affected and hundreds of them could sustain damaging consequences, ranging from critical damage to total collapse. It is also found that in the same districts tsunami inundation covers an area of about 15 km2, resulting in more than 150 000 (165 000 in the case of maximum high

  12. Radiation-induced DNA damage and DNA repair

    International Nuclear Information System (INIS)

    Although DNA undergoes various types of damage from radiation, active oxygen, and the like, a living body has a plurality of DNA repair mechanisms responding to the types of DNA damage. On the other hand, there are a system that results in cell death if the repair is impossible and a mechanism to lead to concretization if further repair is not accurately made. This paper explains the following items as the basic researches on these types of DNA damage and the repair mechanisms: (1) biological effects of DNA damage, (2) effect of DNA damage on DNA synthesis, and (3) effects of DNA damage on cells. It also explains the effects of radiation on cells with a focus on specific mechanism for (1) DNA damage caused by direct action due to radiation and by indirect action due mainly to active oxygen, and (2) DNA repair mechanism that works on DNA double-strand break (DSB). (A.O.)

  13. 电磁辐射对生物体损伤的研究进展*%Progress about biological damage effect of electromagnetic radiation

    Institute of Scientific and Technical Information of China (English)

    祝青鸾; 李俊堂; 高春芳

    2015-01-01

    The electromagnetic wave has been currently widely used in wireless communication, military, medicine, etc. The biological effects on human health have been arousing great concerns of people. Electromagnetic radiation can cause multi -system and multi -organ damage. In this paper , the damaged mechanism of electromagnetic radiation and its related effects on some important organs or systems such as brain , heart, blood and eyes were reviewed.%电磁波目前广泛应用于无线通信、军事、医疗等领域,与此同时,电磁辐射的生物效应和对健康的影响也愈来愈受人们的重视。电磁辐射可引起机体多系统、多脏器的损伤,本文就电磁辐射的损伤机制及其对大脑、心脏、眼睛和血液等重要器官系统影响的研究进展作一综述。

  14. Indoor damage of aged porous natural stone due to thermohygric stress: a case study of opuka stone altar from the St. Vitus Cathedral, Prague (Czech Republic)

    Science.gov (United States)

    Prikryl, Richard; Prikrylova, Jirina; Racek, Martin; Kreislova, Kateřina; Weishauptova, Zuzana

    2016-04-01

    Opuka stone (extremely fine-grained clayey-calcareous silicite) used for a carved stone altar located in the interior of the St. Vitus Cathedral (Prague, Czech Republic) was affected by decay phenomena (formation of the case-hardened surface, its later blistering, flaking and/or powdering of stone substrate) which are similar to those observed in outdoor environments. Through the detailed analytical study (optical microscopy and scanning electron microscopy with energy dispersive spectrometry and x-ray elemental mapping of cross-sections of surface layers, x-ray diffraction of surface layers, ion-exchange chromatography for water-soluble salts, mercury porosimetry) and analysis of long-term indoor environmental monitoring (temperature, relative humidity, sulphur and nitrogen oxides deposition), it has been found that observed decay phenomena, which are manifested on microscale by brittle damage and formation of mode I (tensile) cracks along the exposed surface of the stone, can be interpreted as a result from thermohygric stress occurring on the interface between case hardened surface layer and stone substrate.

  15. Discovery and characterization of artifactual mutations in deep coverage targeted capture sequencing data due to oxidative DNA damage during sample preparation.

    Science.gov (United States)

    Costello, Maura; Pugh, Trevor J; Fennell, Timothy J; Stewart, Chip; Lichtenstein, Lee; Meldrim, James C; Fostel, Jennifer L; Friedrich, Dennis C; Perrin, Danielle; Dionne, Danielle; Kim, Sharon; Gabriel, Stacey B; Lander, Eric S; Fisher, Sheila; Getz, Gad

    2013-04-01

    As researchers begin probing deep coverage sequencing data for increasingly rare mutations and subclonal events, the fidelity of next generation sequencing (NGS) laboratory methods will become increasingly critical. Although error rates for sequencing and polymerase chain reaction (PCR) are well documented, the effects that DNA extraction and other library preparation steps could have on downstream sequence integrity have not been thoroughly evaluated. Here, we describe the discovery of novel C > A/G > T transversion artifacts found at low allelic fractions in targeted capture data. Characteristics such as sequencer read orientation and presence in both tumor and normal samples strongly indicated a non-biological mechanism. We identified the source as oxidation of DNA during acoustic shearing in samples containing reactive contaminants from the extraction process. We show generation of 8-oxoguanine (8-oxoG) lesions during DNA shearing, present analysis tools to detect oxidation in sequencing data and suggest methods to reduce DNA oxidation through the introduction of antioxidants. Further, informatics methods are presented to confidently filter these artifacts from sequencing data sets. Though only seen in a low percentage of reads in affected samples, such artifacts could have profoundly deleterious effects on the ability to confidently call rare mutations, and eliminating other possible sources of artifacts should become a priority for the research community.

  16. Examining food additives and spices for their anti-oxidant ability to counteract oxidative damage due to chronic exposure to free radicals from environmental pollutants

    Science.gov (United States)

    Martinez, Raul A., III

    The main objective of this work was to examine food additives and spices (from the Apiaceae family) to determine their antioxidant properties to counteract oxidative stress (damage) caused by Environmental pollutants. Environmental pollutants generate Reactive Oxygen species and Reactive Nitrogen species. Star anise essential oil showed lower antioxidant activity than extracts using DPPH scavenging. Dill Seed -- Anethum Graveolens -the monoterpene components of dill showed to activate the enzyme glutathione-S-transferase , which helped attach the antioxidant molecule glutathione to oxidized molecules that would otherwise do damage in the body. The antioxidant activity of extracts of dill was comparable with ascorbic acid, alpha-tocopherol, and quercetin in in-vitro systems. Black Cumin -- Nigella Sativa: was evaluated the method 1,1-diphenyl2-picrylhhydrazyl (DPPH) radical scavenging activity. Positive correlations were found between the total phenolic content in the black cumin extracts and their antioxidant activities. Caraway -- Carum Carvi: The antioxidant activity was evaluated by the scavenging effects of 1,1'-diphenyl-2-picrylhydrazyl (DPPH). Caraway showed strong antioxidant activity. Cumin -- Cuminum Cyminum - the major polyphenolic were extracted and separated by HPTLC. The antioxidant activity of the cumin extract was tested on 1,1'-diphenyl-2- picrylhydrazyl (DPPH) free radical scavenging. Coriander -- Coriandrum Sativum - the antioxidant and free-radical-scavenging property of the seeds was studied and also investigated whether the administration of seeds curtails oxidative stress. Coriander seed powder not only inhibited the process of Peroxidative damage, but also significantly reactivated the antioxidant enzymes and antioxidant levels. The seeds also showed scavenging activity against superoxides and hydroxyl radicals. The total polyphenolic content of the seeds was found to be 12.2 galic acid equivalents (GAE)/g while the total flavonoid content

  17. A Study on Biological Characteristics of Perigrapha Circumducta Moth Damaged Seabuckthorn Trees%危害沙棘的围连环夜蛾生物学特性及防治

    Institute of Scientific and Technical Information of China (English)

    崔峻桥

    2011-01-01

    围连环夜蛾在我国多有分布,但看见其幼虫的还是很少,因资料中寄主不祥,笔者经室内外观察。发现其危害多种植物的叶片,更喜欢危害沙棘树的叶片,笔者经2a的室内外观察得知。其生物学特性在辽宁西部每年1代,以蛹越夏及冬。对沙棘树危害较重,对栽植的大果沙棘危害尤为严重,在5a生的沙棘树上有100多头幼虫危害,成虫善飞翔。%Perigrapha circumdueta moth distribute the most part of China, but its larvae is rarely found, due to the authoritative data its host hash' t detailed recordation. Through two years for indoor and outdoor was observed by the author found that harmed many of plants leaves, preferring harm seabuckthorn leaves. The biological characteristics are one generation annually in the western Liaoning, summer and winter in form of the pupa. Heavy damage for seabuckthorn trees, damage the seahuckthorn tree of the Big-fruit is particularly serious, there are more than 100 larvae for 5 years of seabuckthorn trees. The imago is good at fly on wing.

  18. Atlas based brain volumetry: How to distinguish regional volume changes due to biological or physiological effects from inherent noise of the methodology.

    Science.gov (United States)

    Opfer, Roland; Suppa, Per; Kepp, Timo; Spies, Lothar; Schippling, Sven; Huppertz, Hans-Jürgen

    2016-05-01

    Fully-automated regional brain volumetry based on structural magnetic resonance imaging (MRI) plays an important role in quantitative neuroimaging. In clinical trials as well as in clinical routine multiple MRIs of individual patients at different time points need to be assessed longitudinally. Measures of inter- and intrascanner variability are crucial to understand the intrinsic variability of the method and to distinguish volume changes due to biological or physiological effects from inherent noise of the methodology. To measure regional brain volumes an atlas based volumetry (ABV) approach was deployed using a highly elastic registration framework and an anatomical atlas in a well-defined template space. We assessed inter- and intrascanner variability of the method in 51 cognitively normal subjects and 27 Alzheimer dementia (AD) patients from the Alzheimer's Disease Neuroimaging Initiative by studying volumetric results of repeated scans for 17 compartments and brain regions. Median percentage volume differences of scan-rescans from the same scanner ranged from 0.24% (whole brain parenchyma in healthy subjects) to 1.73% (occipital lobe white matter in AD), with generally higher differences in AD patients as compared to normal subjects (e.g., 1.01% vs. 0.78% for the hippocampus). Minimum percentage volume differences detectable with an error probability of 5% were in the one-digit percentage range for almost all structures investigated, with most of them being below 5%. Intrascanner variability was independent of magnetic field strength. The median interscanner variability was up to ten times higher than the intrascanner variability.

  19. Colonization and Biology of Phlebotomus pa­patasi, the Main Vector of Cutaneous Leishmani­asis due to Leshmania major

    Directory of Open Access Journals (Sweden)

    Yaghoobi-Ershadi MR

    2007-09-01

    Full Text Available Background: Laboratory bred sand flies are essential for the study of different biological phenomena including the transmis­sion dynamics of Leishmania. The aim of the study was to determine the suitable situation for colonization and main­tenance of Iranian strain of Phlebotomus papatasi at laboratory conditions from an endemic focus of cutaneous leishmani­asis due to Leishmania major.Methods: One hundred and thirty P. papatasi were collected by CDC miniature light traps and aspirator from indoors in Badrood, central Iran. The fly was maintained by the procedures of Modi & Tesh (1983 with minor modifications for 7 generations. Results: Minimum and maximum rate of productivity was calculated to be 8.5 and 56.1 in F7 and F3, respectively and signifi­cant difference was observed among productivity of some generations (P< 0.001. The sex ratio ranged between 70(F1 and 101.8(F6. The mean duration of egg to adult emergence varied between 47.21±4.46 and 52.6±7.85 days. The life cycle was completed in 34.4 to 60 days at 26±1 ºC. Conclusion: P. papatasi was colonized and maintained successfully for the first time as a laboratory strain. Using larval diet without liver powder is recommended. The blood of white hamster was preferred to golden hamster and guinea pig for the sand fly vector blood feeding at the insectary.

  20. A quantification of damage and assessment of economic loss due to crop raiding by Asian Elephant Elephas maximus (Mammalia: Proboscidea: Elephantidae: a case study of Manas National Park, Assam, India

    Directory of Open Access Journals (Sweden)

    Naba K. Nath

    2015-02-01

    Full Text Available A study was carried out in Manas National Park, Assam in northeastern India between 2007 and 2009 to understand the magnitude of human-elephant conflict through a quantification of damage and assessment of economic loss. A cluster of six villages adjacent to the Park was selected for this study. Five major agricultural crops were grown during the study period of which three were raided by elephants: winter paddy, autumn paddy and pulses. Paddy was the principle crop central to the farmers’ subsistence. Winter paddy was the most cultivated crop and autumn paddy was the least cultivated. The incidence rate of crop raiding was highest for autumn paddy and lowest for pulses. Overall economic loss due to crop raiding was negligible, however at the individual farmer level, it was quite high. The study revealed that human-elephant conflict is not so severe, indicating ample opportunity for human-elephant coexistence in the region. Crop fields adjacent to the Park were particularly vulnerable to crop raiding which necessitates creation of a buffer zone. The frequency of raiding and the extent of damage was found to be significantly less in crop fields which were guarded by farmers. This was due to traditional crop guarding practices being followed in the region, the strengthening of which could effectively reduce annual crop loss and thus human-elephant conflict could be minimized to a large extent.

  1. THERMO-POROELASTIC COUPLING ANALYSIS OF ROCK DAMAGE AROUND WELLBORE DUE TO CO2 INJECTION%CO2注入引起井筒周围岩石损伤的热孔弹耦合分析

    Institute of Scientific and Technical Information of China (English)

    李琦; 井淼

    2013-01-01

    以岩石的耦合-去耦合解析为主线,在三场耦合方程中导入损伤变量,建立岩石损伤过程中的热孔弹耦合模型。通过把均质弹性介质材料的热孔弹耦合模型的有限元解同去耦合解析解的对比,验证有限元数值解的精确性。然后,利用该耦合模型研究CO2注入后井筒周围的应力状态和损伤情况。最后,针对服从Weibull分布的非均质岩石材料,研究CO2注入后非均质岩石渗流性质的改变。结果表明,超临界CO2的注入会对岩石的强度和渗透性产生影响,较高的注入速率会引起岩石的受拉破坏并导致拉伸损伤范围的扩大。非均质材料更容易发生岩石的损伤和渗透性增加。%A coupled thermo-poroelastic model is proposed with integration of a damage factor. The proposed thermo-poroelastic model is firstly utilized to simulate the thermo-hydro-mechanical(THM) response of homogeneous elastic medium;and its accuracy of the numerical results is verified through comparing to the decoupled analytical solution. Secondly,the thermo-poroelastic model is employed to predict stress response and damage propagation around the wellbore due to CO2 injection. Finally,this model is applied to heterogeneous rock under a Weibull distribution to predict stress response and permeability change. The experimental results indicate that the supercritical CO2 injection can change the rock′s strength state and permeability distribution significantly. Too high injection rates will facilitate the tensile damage and extend the tensile damage zone. Heterogeneous rock material is more vulnerable to tensile damage and permeability increase.

  2. Lung Damage due to Chemotherapeutic Agents

    Directory of Open Access Journals (Sweden)

    Serdar Kalemci

    2014-12-01

    Full Text Available Chemotherapeutic drug-induced pulmonary toxicity not only emerges in cumulative doses, but also can be observed even at low dosages. Combined administration of many drugs, concurrent radiotherapy applications, opportunistic infections, lymphangitic tumor extension and pleural metastases complicate the disease diagnosis.

  3. The Biological Effectiveness of Silicon Ions is Significantly Higher than Iron Ions for the Induction of Chromosome Damage in Human Lymphocytes

    Science.gov (United States)

    George, Kerry; Hada, Megumi; Cucinotta, F. A.

    2010-01-01

    Chromosome aberrations were measured in human peripheral blood lymphocytes after in vitro exposure to Si-28-ions with energies ranging from 90 to 600 MeV/u, or Fe-56-ions with energies ranging from 200 to 5,000 MeV/u. The LET of the various Fe beams in this study ranged from 145 to 440 keV/micron and the LET Si ions ranged from 48 to 158 keV/micron. Doses delivered were in the 10 to 200 cGy range. Dose response curves for chromosome exchanges in cells at first division after exposure, measured using fluorescence in situ hybridization (FISH) with whole chromosome probes, were fitted with linear or linear-quadratic functions. The relative biological effectiveness (RBE) was estimated from the initial slope of the dose response curve for chromosome damage with respect to gamma-rays. The estimates of RBE(sub max) values for total chromosome exchanges ranged from 4.4+/-0.4 to 31.5+/-2.6 for Fe ions, and 11.8+/-1.0 to 42.2+/-3.3 for Si ions. The highest RBE(sub max) value for Fe ions was obtained with the 600 Mev/u beam and 170 MeV/u beam produced the highest RBE(sub max) value for Si ions. For both ions the RBE(sub max) values increased with LET, reaching a maximum at about 180 keV/micron for Fe and about 100 keV/micron for Si, and decreased with further increase in LET.

  4. 考虑地震损伤的单层球面网壳结构静力稳定性%Static Stability of Single-layer Latticed Shells Considering Damage Due to Earthquake

    Institute of Scientific and Technical Information of China (English)

    李永梅; 胡琨; 张微敬; 李运运

    2015-01-01

    To study the effect on the static performance of single-layer latticed shells under earthquake damage, based on the material constructive relationship considering damage cumulative effect, the dynamic stable analysis is first carried out for a K8 type and single-layer latticed shell through the incremental dynamic analysis ( IDA) method, in which B-R kinetic criterion in combination with plastic strain energy density is put forward as the criterion for judging dynamic instability of single-layer latticed shells, from which the dynamic critical load value can be derived. Then, nonlinear buckling analysis by the arc-length method combined with Newton-Raphson method is done to the damaged structure due to earthquake, from which the static critical load value can be derived. Results show that the reduction to the structural static stable ability will be obvious after considering damage accumulation effect for single-layer latticed shells, which can be a reference for the structural seismic design, performance assessment, and engineering repair or reinforcement after earthquake.%为了研究地震损伤对单层网壳结构静力稳定性能的影响,基于考虑材料损伤累积效应的本构模型,对一K8型单层球面网壳结构,首先利用动态增量( incremental dynamic analysis,IDA)方法对单层网壳结构进行动力稳定分析,提出将B-R准则与塑性应变能曲线相结合作为结构动力失稳破坏的判断准则,得到结构动力失稳临界值;然后采用弧长法和Newton-Raphson法相结合的增量迭代法对损伤后的结构进行非线性屈曲分析,得到震后结构的静力稳定临界荷载。结果表明:考虑地震损伤累积效应的结构静力稳定性能显著降低,为该类结构抗震设计、性能评估和震后修复、加固提供参考。

  5. Clinical light damage to the eye

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D.

    1987-01-01

    This book contains four sections: The Nature of Light and of Light Damage to Biological Tissues; Light Damage to the Eye; Protecting the Eye from Light Damage; and Overview of Light Damage to the Eye. Some of the paper titles are: Ultraviolet-Absorbing Intraocular Lens Implants; Phototoxic Changes in the Retina; Light Damage to the Lens; and Radiation, Light, and Sight.

  6. CHARACTERIZATION OF DAMAGED MATERIALS

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, P C; Dehaven, M; McClelland, M; Chidester, S; Maienschein, J L

    2006-06-23

    Thermal damage experiments were conducted on LX-04, LX-10, and LX-17 at high temperatures. Both pristine and damaged samples were characterized for their material properties. A pycnometer was used to determine sample true density and porosity. Gas permeability was measured in a newly procured system (diffusion permeameter). Burn rate was measured in the LLNL strand burner. Weight losses upon thermal exposure were insignificant. Damaged pressed parts expanded, resulting in a reduction of bulk density by up to 10%. Both gas permeabilities and burn rates of the damaged samples increased by several orders of magnitude due to higher porosity and lower density. Moduli of the damaged materials decreased significantly, an indication that the materials became weaker mechanically. Damaged materials were more sensitive to shock initiation at high temperatures. No significant sensitization was observed when the damaged samples were tested at room temperature.

  7. Systems biology approach identifies the kinase Csnk1a1 as a regulator of the DNA damage response in embryonic stem cells

    DEFF Research Database (Denmark)

    Carreras Puigvert, Jordi; von Stechow, Louise; Siddappa, Ramakrishnaiah;

    2013-01-01

    screen targeting all kinases, phosphatases, and transcription factors with global transcriptomics and phosphoproteomics to map the DDR in mouse embryonic stem cells treated with the DNA cross-linker cisplatin. Networks derived from canonical pathways shared in all three data sets were implicated in DNA......In pluripotent stem cells, DNA damage triggers loss of pluripotency and apoptosis as a safeguard to exclude damaged DNA from the lineage. An intricate DNA damage response (DDR) signaling network ensures that the response is proportional to the severity of the damage. We combined an RNA interference....... Instead, this response occurred through reduced abundance of Csnk1a1 (CK1α), a kinase that inhibits β-catenin. Together, our findings reveal a balance between p53-mediated elimination of stem cells (through loss of pluripotency and apoptosis) and Wnt signaling that attenuates this response to tune...

  8. Damage at a superheater in a combined cycle plant due to insufficient phase separation in the drum; Schaden an einem Ueberhitzer einer GuD-Anlage durch unzureichende Phasentrennung in der Trommel

    Energy Technology Data Exchange (ETDEWEB)

    Reichel, H.H. [GB PowerTech e.V., Essen (Germany). Werkstofflabor; Weiher, R. [VGB PowerTech e.V., Essen (Germany); Gebert, H. [Bewag Aktiengesellschaft, Berlin (Germany). Abt. EZ; Hopp, G. [Bewag Aktiengesellschaft, Berlin (Germany). Abt. EEB; Huehn, B. [Bewag Aktiengesellschaft, Berlin (Germany). Abt. EZP

    2001-07-01

    In spring 1999 severe wear was detected at the internal wall of finned tubes in the first of two HRSG of the newly constructed combined cycle plant of the Mitte station of Bewag. The damage occurred at the entrance of the HP superheater and resulted in wall fractures. The laboratory examination revealed insufficient phase separation in the drum resulting in boiler water entering the superheater tubes. Due to the concentration of water constituents this process led to increased hot water oxidation. The root cause identified was confirmed by an examination of the drum/demister design. As precautionary measure the active area of the demister was enlarged by 50% and the inspection possibilities in the critical area were improved. (orig.) [German] Im ersten von zwei Abhitzekesseln der neu errichteten GuD-Anlage im Heizkraftwerk Mitte der Bewag sind nach relativ kurzer Betriebszeit starke Abzehrungen der Innenwand der Rippenrohre im Eintrittsbereich des HD-Ueberhitzers aufgetreten, die zu Wanddurchbruechen gefuehrt haben. Das Ergebnis von Laboruntersuchung wies hin auf eine mangelhafte Phasentrennung in der Trommel und dadurch Eintrag von Kesselwasser in die Ueberhitzerrohre. Aufgrund der sich aufkonzentrierenden Wasserinhaltstoffe hat dieser Vorgang zu einer katastrophal verstaerkten Heisswasseroxidation gefuehrt. Die ermittelte Schadensursache wurde durch Begutachtung der Trommel-/Demisterauslegung bestaetigt. (orig.)

  9. PRESENTED AT TRIANGLE CONSORTIUM OF REPRODUCTIVE BIOLOGY, CHAPEL HILL, NC: GST M1 GENOTYPE INFLUENCES SPERM DNA DAMAGE ASSOCIATED WITH EXPOSURE TO AIR POLLUTION

    Science.gov (United States)

    Exposure to episodic air pollution in the Czech Republic has been associated with abnormal semen quality and sperm DNA damage (EHP 108:887;2000). A subsequentlongitudinal study evaluated semenfrom 36 men sampled up to 7 times over a period of two years to capture exposures durin...

  10. Potential biological indicators of multi-organ damage: Application to radiation accident victims; Bio-indicateurs potentiels d'atteinte multi-organe: application au cas des victimes d'irradiation accidentelles

    Energy Technology Data Exchange (ETDEWEB)

    Bertho, J.M.; Souidi, M.; Gourmelon, P. [Institut de Radioprotection et de Surete Nucleaire (IRSN), Dir. de la Radioprotection de l' Homme 92 - Fontenay-aux-Roses (France)

    2009-09-15

    Accidental irradiations induce a complex pathological situation, difficult to assess and to treat. However, recent results describing new biological indicators of radiation-induced damages such as Flt3-ligand, citrulline and oxy-sterol concentration in the plasma, together with results obtained in large animal models of high dose irradiation, allowed a better understanding of pathophysiological mechanisms induced by uncontrolled irradiations. This conducted to leave the classical paradigm of the acute radiation syndrome, described as the association of three individual syndromes, the hematopoietic syndrome, the gastro-intestinal syndrome and the cerebrovascular syndrome, in favour of a multiple organ dysfunction syndrome, with the implication of other organs and systems. Follow-up of victims from two recent radiation accidents brings a confirmation of the usefulness of the newly described biological indicators, and also a partial confirmation of this new concept of a multiple organ dysfunction syndrome. (authors)

  11. Bitumen and biocarbon : land use conversions and loss of biological carbon due to bitumen operations in the Boreal forests of Alberta, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Lee, P.; Cheng, R.

    2009-07-01

    This paper discussed land use changes, biological carbon content, and the potential greenhouse gas (GHG) emissions caused by existing and future oil sands mining and in situ extraction in Alberta, Canada. The study focused on estimating changes to the natural ecosystems caused by open pit mines, tailings ponds, mine waste, overburden piles and other major infrastructure put in place by surface mining activities. The study showed that a total of 488,968 ha of peatlands, mineral wetlands, and upland forest ecosystems have undergone changes as a result of oil sands mining activities. Natural ecosystems that have undergone land use changes as a result of exploration wells, production wells, access roads, pipelines, and other infrastructure related to existing and potential in situ operations totalled 1,124,919 ha. If all 578.9 megatonnes of carbon produced by oil sands mines in Alberta were emitted, it is likely that 873.4 megatonnes of carbon dioxide (CO{sub 2}) would be released into the atmosphere. The average annual release of CO{sub 2} was estimated at 8.7 megatonnes over a 100 year period. 59 refs., 11 tabs., 12 figs.

  12. Ion irradiation induced direct damage to DNA

    CERN Document Server

    Wang, Wei; Su, Wenhui

    2008-01-01

    Ion beams have been widely applied in a few biological research fields such as radioactive breeding, health protection, and tumor therapy. Up to now many interesting and impressive achievements in biology and agriculture have been made. Over the past several decades, scientists in biology, physics, and chemistry have pursued investigations focused on understanding the mechanisms of these radiobiological effects of ion beams. From the chemical point of view, these effects are due to the ion irradiation induced biomolecular damage, direct or indirect. In this review, we will present a chemical overview of the direct effects of ion irradiation upon DNA and its components, based on a review of literature combined with recent experimental results. It is suggested that, under ion bombardment, a DNA molecule undergoes a variety of processes, including radical formation, atomic displacement, intramolecular bond-scissions, emission of fragments, fragment recombination and molecular crosslink, which may lead to genetic...

  13. Relative biological effectiveness of carbon ions for tumor control, acute skin damage and late radiation-induced fibrosis in a mouse model

    DEFF Research Database (Denmark)

    Sørensen, Brita Singers; Horsman, Michael Robert; Alsner, Jan;

    2015-01-01

    Background. The aim of the present study was to compare the biological effectiveness of carbon ions relative to x-rays between tumor control, acute skin reaction and late RIF of CDF1 mice. Material and methods. CDF1 mice with a C3H mouse mammary carcinoma implanted subcutaneously on the foot of t...

  14. Mapping the conformations of biological assemblies

    CERN Document Server

    Schwander, P; Phillips, G N; Jr.,; Ourmazd, A

    2009-01-01

    Mapping conformational heterogeneity of macromolecules presents a formidable challenge to X-ray crystallography and cryo-electron microscopy, which often presume its absence. This has severely limited our knowledge of the conformations assumed by biological systems and their role in biological function, even though they are known to be important. We propose a new approach to determining to high resolution the three-dimensional conformations of biological entities such as molecules, macromolecular assemblies, and ultimately cells, with existing and emerging experimental techniques. This approach may also enable one to circumvent current limits due to radiation damage and solution purification.

  15. Design, synthesis and biological evaluation of novel chiral oxazino-indoles as potential and selective neuroprotective agents against Aβ25-35-induced neuronal damage.

    Science.gov (United States)

    Chen, Jing; Tao, Ling-Xue; Xiao, Wei; Ji, Sha-Sha; Wang, Jian-Rong; Li, Xu-Wen; Zhang, Hai-Yan; Guo, Yue-Wei

    2016-08-01

    A series of chiral oxazino-indoles have been synthesized via a key intermolecular oxa-Pictet-Spengler reaction. These compounds exhibited significant and selective neuroprotective effects against Aβ25-35-induced neuronal damage. This is the first report of evaluating the influence of chiral diversity of oxazino-indoles on their neuroprotective activities, with the structure-activity relationship been analyzed. The highly active compounds 3f, 3g, 4g, 4h, and 6b all performed over 90% cell protection, providing a new direction for the development of neuroprotective agents against Alzheimer's disease. PMID:27301369

  16. On the way of calculating the atmospheric environmental damage due to the pollution in the coal-mining resource cities%煤炭资源型城市大气环境污染损失核算研究

    Institute of Scientific and Technical Information of China (English)

    冯思静; 马云东; 刘辉; 潘日芳

    2012-01-01

    The present article is inclined to introduce an improved method for calculating the atmospheric environmental damage due to the pollution in the coal-mining resource cities by taking Fuxin city as our case study. As to the methods for calculating environmental values in the environmental economics, it is of great necessity to mention the functional relationship among the physical quantity of loss, the value quantity of loss due to the pollution the coal production brings about to the environment. In order to calculate the economic loss caused by the atmospheric environmental pollution, we have prepared an equation and calculation method by joining the environmental value evaluation methods, such as human capital approach and the market value law, the economic loss caused by the atmospheric environmental pollution derived from the coal exploitation of the city in terms of currency. In order to analyze and evaluate the actualities of the atmospheric environmental quality loss and existing problems generated from coal mining quantitatively and qualitatively, this article put forward the calculation method by accounting the physical quantity and value quantity respectively. Such calculation can provide reference to the construction of ecological compensation and ecological regionaliza-tion. The calculation result of ours shows: the atmospheric environ-mental pollution loss caused by coal exploitation in the city in 2010 was about 1.266 billion Yuan, amounting to 80.09 Yuan loss for per metric ton coal, in which the cost of human health is thought of 65.63 % of the total loss, which is regarded as the biggest loss. Since the regions involved and evaluated are difficult to conform with the natural ecological environment remands, the population scale and socioeconomic development situation when they are evaluated with the end-results checking method, the accounting results of this article can only be treated as a reference to the upper limit. The uncertainty of the

  17. A molecular biological study on the identification of the molecular species of DNA polymerases for repairing radiation-damaged DNA and the factors modifying the mutation rate

    International Nuclear Information System (INIS)

    Aiming at prevention and treatment of radiation damages, the authors have been investigating DNA damages by X-ray and its repairing mechanism, however, the molecular species of DNA polymerase which mediate the repairing could not been identified by biochemical methods using various inhibitors because of their low specificity. Therefore, in this study, anti-sense oligonucleotides for DNA polymerase α, δ and ε were obtained by chemical synthesis and transduced into human fibroblast cell, NB1RGB by three methods; endocytotic method, electroporation method and lipofection method. For the first method, the addition of those peptides into the cell culture at 5 μM inhibited the polymerase activity by up to 30% and it was economically difficult to use at higher concentrations than it. For the electroporation method, different conditions were tested in the respects of initial potential, time constant and buffer, but the uptake of thimidine was scarcely decreased in the surviving cells, suggesting that the surviving rate would be short in the cells electroporated with those anti-sense peptides. For the lipofection method, among several cationic lipids tested, lipofectamine significantly enlarged the decrease of thymidine uptake by anti-sense δ, however it was considered that its application to DNA repairing is difficult because lipofectamine is strongly cytotoxic. Therefore, construction of a vector which allows to express anti-sense RNA in those cells is undertaken. (M.N.)

  18. Examination of the biological effects of high anionic peroxidase production in tobacco plants grown under field conditions. I. Insect pest damage.

    Science.gov (United States)

    Dowd, Patrick F; Lagrimini, L Mark

    2006-04-01

    At least 25 wild type and high peroxidase tobacco Nicotiana tabacum L. plants were examined semiweekly over several weeks for pest insect distribution and damage in a 2 year field study. Incidence and/or severity of naturally occurring caterpillar damage (dingy cutworm (Feltia ducens Walker), black cutworm (Agrotis ipsilon (Hufnagel), tobacco hornworm (Manduca sexta L.), and false tobacco budworm (= corn earworm Helicoverpa zea (Boddie)) was significantly reduced at several sample dates for high peroxidase vs. wild type plants. These results parallel those of prior laboratory studies with caterpillars. The number of adult whiteflies (Trialeurodes vaporariorum (Westwood) per plant was significantly reduced on high peroxidase compared to wild type plants on most sample dates in both years. The number of plants with leaves containing >100 aphids (primarily Myzus persicae Sulzer) per leaf on high peroxidase plants was significantly lower that on wild type plants after an equivalent invasion period in both years. A significantly higher proportion of aphids were found dead on leaf five of high peroxidase compared to wild type plants at most sample dates in both years. These results indicate that high peroxidase plants have resistance to a wide range of insects, implicating this enzyme as a broad range resistance mechanism.

  19. Damage control apronectomy for necrotising fasciitis and strangulated umbilical hernia.

    LENUS (Irish Health Repository)

    Coyle, P

    2012-01-31

    We present a case of a 50-year-old morbidly obese woman who presented with a case of necrotizing fasciitis of the anterior abdominal wall due to a strangulated umbilical hernia. The case was managed through damage control surgery (DCS) with an initial surgery to stabilise the patient and a subsequent definitive operation and biological graft hernia repair. We emphasise the relevance of DCS principles in the management of severe abdominal sepsis.

  20. Biological evaluation of a cytotoxic 2-substituted benzimidazole copper(II) complex: DNA damage, antiproliferation and apoptotic induction activity in human cervical cancer cells.

    Science.gov (United States)

    Qiao, Xin; Ma, Zhong-Ying; Shao, Jia; Bao, Wei-Guo; Xu, Jing-Yuan; Qiang, Zhao-Yan; Lou, Jian-Shi

    2014-02-01

    Exploring novel chemotherapeutic agents is a great challenge in cancer medicine. To that end, 2-substituted benzimidazole copper(II) complex, [Cu(BMA)Cl2]·(CH3OH) (1) [BMA = N,N'-bis(benzimidazol-2-yl-methyl)amine], was synthesized and its cytotoxicity was characterized. The interaction between complex 1 and calf thymus DNA was detected by spectroscopy methods. The binding constant (K b = 1.24 × 10(4 )M(-1)) and the apparent binding constant (K app = 6.67 × 10(6 )M(-1)) of 1 indicated its moderate DNA affinity. Complex 1 induced single strand breaks of pUC19 plasmid DNA in the presence of H2O2 through an oxidative pathway. Cytotoxicity studies proved that complex 1 could inhibit the proliferation of human cervical carcinoma cell line HeLa in both time- and dose-dependent manners. The results of nuclei staining by Hoechst 33342 and alkaline single-cell gel electrophoresis proved that complex 1 caused cellular DNA damage in HeLa cells. Furthermore, treatment of HeLa cells with 1 resulted in S-phase arrest, loss of mitochondrial potential, and up-regulation of caspase-3 and -9 in HeLa cells, suggesting that complex 1 was capable of inducing apoptosis in cancer cells through the intrinsic mitochondrial pathway.

  1. Sun Damage

    Science.gov (United States)

    ... rash and rashes clinical tools newsletter | contact Share | Sun Damage A A A The sun has a profound effect over years of exposure ... changes. Exposure to ultraviolet (UV) light from the sun accounts for most premature skin aging. Many skin ...

  2. Damage Distributions

    DEFF Research Database (Denmark)

    Lützen, Marie

    2001-01-01

    The purpose of Task 2.2 of the HARDER project is according to the work package description: For various structural configurations of the struck ship and using the results of Task 2.1, the probability distributions for the damage location and size will be derived. The format will be similar to the...... damage statistics and bow height statistics for vessels in the world fleet. The proposals for the p-, r-, and v-factors have been compared to factors from current regulation by examples.......The purpose of Task 2.2 of the HARDER project is according to the work package description: For various structural configurations of the struck ship and using the results of Task 2.1, the probability distributions for the damage location and size will be derived. The format will be similar to the p...... between the damage location, the damage sizes and the main particulars of the struck vessel. From the numerical simulation and the analyse of the damage statistics it is found that the current formulation from the IMO SLF 43/3/2 can be used as basis for determination of the p-, r-, and v...

  3. Possible Radiation-Induced Damage to the Molecular Structure of Wooden Artifacts Due to Micro-Computed Tomography, Handheld X-Ray Fluorescence, and X-Ray Photoelectron Spectroscopic Techniques

    Directory of Open Access Journals (Sweden)

    Madalena Kozachuk

    2016-05-01

    Full Text Available This study was undertaken to ascertain whether radiation produced by X-ray photoelectron spectroscopy (XPS, micro-computed tomography (μCT and/or portable handheld X-ray fluorescence (XRF equipment might damage wood artifacts during analysis. Changes at the molecular level were monitored by Fourier transform infrared (FTIR analysis. No significant changes in FTIR spectra were observed as a result of μCT or handheld XRF analysis. No substantial changes in the collected FTIR spectra were observed when XPS analytical times on the order of minutes were used. However, XPS analysis collected over tens of hours did produce significant changes in the FTIR spectra.

  4. Experiment on damage in K9 glass due to repetition rate pulsed CO2 laser radiation%重频脉冲CO2激光损伤K9玻璃的实验

    Institute of Scientific and Technical Information of China (English)

    王玺; 卞进田; 李华; 聂劲松; 孙晓泉; 尹学忠; 雷鹏

    2013-01-01

      对脉冲CO2激光在不同重频模式下损伤K9玻璃进行了实验研究。采用输出能量为10 J,脉宽为90 ns,重复频率在100 Hz至300 Hz之间连续可调的脉冲CO2激光器,对K9玻璃样品进行了激光损伤实验,观察到两次不同重频条件下样品的损伤形貌。实验结果表明,重频越高,对样品的损伤程度就越严重;应力损伤成为K9玻璃激光损伤的最主要的原因,在重频强激光的辐照下,K9玻璃表面出现强烈的等离子体闪光,伴随明显的熔融气化破坏,并形成等离子体爆轰波。爆轰波对玻璃材料产生了严重的力学冲击作用,这种应力作用足以对K9玻璃造成毁灭性破坏。运用有限元分析对激光辐照K9玻璃的温度与应力分布进行仿真,其计算结果与实验基本吻合。%  In this paper, the experiment on damage in K9 glass induced by pulsed CO2 laser under different repetition rates was carried out, which had a pulse width of 90 ns. The laser pulse energy was 10 J and the repetition rate was kept within the range of 100 Hz to 300 Hz. The damage morphologies of two kind repetition rates after laser irradiation were characterized. The experimental results indicate that the effect of laser irradiation on samples can be affected considerably by the change of laser repetition rate, and the intensity of damage morphology on the sample increases with the laser repetition rate, and the damage in K9 glass induced by pulsed CO2 laser is dominated by stress. As a result, the plasma detonation wave induced by laser occured, the material was broken result from the melting and evaporation of K9 glass. It is shown that the plasma detonation wave affected stress damage considerably, and this mechanical effect almost destroyed K9 glass sample. A numerical simulation was performed to calculate temperature and stress distributions in K9 glass sample irradiated by pulsed CO2 laser using finite element method. The model

  5. Laboratory Evaluation of Aggregate Polishing as a function of Load and Velocity : Application to the Prediction of Damages on Skid Resistance of Pavement Surface due to Trucks and Passenger Cars

    OpenAIRE

    Kane, Malal; ZHAO, Dan; De Larrard, François; Do, Minh Tan

    2012-01-01

    Skid resistance of road surfaces depends mostly on pavement texture. This texture is usually divided to two components:microtexture and macrotexture. Microtexture refers to the smallscale texture of the road aggregate component while macrotexture refers to the large-scale texture of the road as a whole due to the aggregate particle arrangement. Both components contribute to the generation of friction between tyre and road. However, due to traffic, the firstcited component is continuously poli...

  6. 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...

  7. 注入水中悬浮微粒导致储层伤害网络模拟研究%Network Simulation of Formation Damage Due to Suspended Particles in Injection Water

    Institute of Scientific and Technical Information of China (English)

    冯其红; 韩晓冬; 王守磊; 张欣; 周文胜

    2014-01-01

    注入流体中的悬浮固体微粒随流体进入储层后会对储层造成伤害,导致储层渗透率降低,明确不同因素对储层伤害的影响规律对现场储层伤害的预防和治理有十分重要的意义。因此应用网络模拟方法对不同条件下储层伤害变化规律及孔喉变化规律进行了研究。模拟结果表明:随驱替的不断进行,孔喉半径总体逐渐减小,且距离注入端面越近,孔喉半径减小幅度越大;注入流量越小、注入流体内微粒浓度越大、流体黏度越小、微粒粒径越大,越有利于微粒的沉积,造成的储层伤害越严重。%Particles suspended in injection water could damage the formation and decrease the permeability. And it’s of great importance to study the impact of various factors on the formation impairment for its prevention and treatment. In our study here,pore scale network modeling method is applied to the study of the formation damage patterns and the change of the pore-throat radius under various conditions. In network models,different microcosmic particle variation mechanisms are taken into consideration. The results indicate that the pore-throat radius will decrease with the process of waterflooding and pore-throats that are closer to the inlet face will have a much higher decrease of their radius. Besides,the lower the flow rate is,the higher the particle concentration in injection water is,the lower the fluid viscosity and bigger particle size,it will be beneficial for the formation damage.

  8. 沥青层模量累积疲劳损伤衰减的试验研究%Experimental Study on Modulus Degradation of Asphalt Layer due to Cumulative Fatigue Damage

    Institute of Scientific and Technical Information of China (English)

    薛连旭; 陈少幸; 张肖宁

    2008-01-01

    在加速加载试验过程中,采用落锤式弯沉仪测量不同轴载作用次数下路面弯沉,反算沥青层模量,得到路面整个寿命周期的沥青层模量衰减模型.结果表明,累积疲劳损伤下,沥青层模量与加载作用在半对数坐标成线性相关.%Falling weight deflectometer Was used tomeasure the deflection of surface pavement under different ALF axle loading in accelerated loading test.Back-calculated the modulus of asphalt layer.determined the reduetion in modulus of the asphalt layer during the whole life of pavement are presented.The result shows a linear relationship between asphalt layer modulus and cumulative fatigue damage plated on semilog scales.

  9. Earthquake damage to underground facilities

    International Nuclear Information System (INIS)

    The potential seismic risk for an underground nuclear waste repository will be one of the considerations in evaluating its ultimate location. However, the risk to subsurface facilities cannot be judged by applying intensity ratings derived from the surface effects of an earthquake. A literature review and analysis were performed to document the damage and non-damage due to earthquakes to underground facilities. Damage from earthquakes to tunnels, s, and wells and damage (rock bursts) from mining operations were investigated. Damage from documented nuclear events was also included in the study where applicable. There are very few data on damage in the subsurface due to earthquakes. This fact itself attests to the lessened effect of earthquakes in the subsurface because mines exist in areas where strong earthquakes have done extensive surface damage. More damage is reported in shallow tunnels near the surface than in deep mines. In mines and tunnels, large displacements occur primarily along pre-existing faults and fractures or at the surface entrance to these facilities.Data indicate vertical structures such as wells and shafts are less susceptible to damage than surface facilities. More analysis is required before seismic criteria can be formulated for the siting of a nuclear waste repository

  10. DNA damage and repair in plants

    International Nuclear Information System (INIS)

    The biological impact of any DNA damaging agent is a combined function of the chemical nature of the induced lesions and the efficiency and accuracy of their repair. Although much has been learned frommicrobes and mammals about both the repair of DNA damage and the biological effects of the persistence of these lesions, much remains to be learned about the mechanism and tissue-specificity of repair in plants. This review focuses on recent work on the induction and repair of DNA damage in higher plants, with special emphasis on UV-induced DNA damage products. (author)

  11. In vitro evaluation of {sup 213}Bi-rituximab versus external gamma irradiation for the treatment of B-CLL patients: relative biological efficacy with respect to apoptosis induction and chromosomal damage

    Energy Technology Data Exchange (ETDEWEB)

    Vandenbulcke, Katia; Lahorte, Christophe; Slegers, Guido [Department of Radiopharmacy, Faculty of Pharmaceutical Sciences, Ghent University, Harelbekestraat 72, 9000, Gent (Belgium); De Vos, Filip; Dierckx, Rudi A. [Division of Nuclear Medicine, Ghent University Hospital (Belgium); Offner, Fritz [Department of Hematology, Ghent University Hospital (Belgium); Philippe, Jan [Department of Clinical Chemistry, Ghent University Hospital (Belgium); Apostolidis, Christos; Molinet, Roger; Nikula, Tuomo K. [European Commission, Joint Research Centre, Institute for Transuranium Elements, Karlsruhe (Germany); Bacher, Klaus; De Gelder, Virginie; Vral, Anne; Thierens, Hubert [Department of Anatomy, Embryology, Histology and Medical Physics, Ghent University (Belgium)

    2003-10-01

    External source radiotherapy and beta radioimmunotherapy (RIT) are effective treatments for lymphoid malignancies. The development of RIT with alpha emitters is attractive because of the high linear energy transfer (LET) and short path length, allowing higher tumour cell kill and lower toxicity to healthy tissues. We assessed the relative biological efficacy (RBE) of alpha RIT (in vitro) compared to external gamma irradiation with respect to induction of apoptosis in B chronic lymphocytic leukaemia (B-CLL) and induction of chromosomal damage in healthy donor B and T lymphocytes. The latter was measured by a micronucleus assay. {sup 213}Bi was eluted from a {sup 225}Ac generator and conjugated to CD20 antibody (rituximab) with CHX-A''-DTPA as a chelator. B-CLL cells from five patients were cultured for 24 h in RPMI/10% FCS while exposed to {sup 213}Bi conjugated to CD20 antibody or after external {sup 60}Co gamma irradiation. Binding assays were performed in samples of all patients to calculate the total absorbed dose. Apoptosis was scored by flow cytometric analyses of the cells stained with annexin V-FITC and 7-AAD. Apoptosis was expressed as % excess over spontaneous apoptosis in control. Full dose range experiments demonstrated {sup 213}Bi-conjugated CD20 antibody to be more effective than equivalent doses of external gamma irradiation, but showed that similar plateau values were reached at 10 Gy. The RBE for induction of apoptosis in B-CLL was 2 between 1.5 and 7 Gy. The micronucleus yield in lymphocytes of healthy volunteers was measured to assess the late toxicity caused by induction of chromosomal instability. While gamma radiation induced a steady increase in micronucleus yields in B and T cells, the damage induced by {sup 213}Bi was more dramatic, with RBE ranging from 5 to 2 between 0.1 Gy and 2 Gy respectively. In contrast to gamma irradiation, {sup 213}Bi inhibited mitogen-stimulated mitosis almost completely at 2 Gy. In conclusion, high

  12. Changes of biological clock protein in neonatal rats with hypoxic-ischemic brain damage%缺氧缺血性脑损伤新生大鼠松果体钟基因表达的变化

    Institute of Scientific and Technical Information of China (English)

    李永富; 金美芳; 孙斌; 冯星

    2013-01-01

    Objective To study the effects of biological clock protein on circadian disorders in hypoxic-ischemic brain damage ( HIBD) by examining levels of CLOCK and BMAL1 proteins in the pineal gland of neonatal rats. Methods Seventy-two 7-day-old Sprague-Dawley (SD) rats were randomly divided into sham-operated and HIBD groups. HIBD model was prepared according to the modified Levine method. Western blot analysis was used to measure the levels of CLOCK and BMAL1 in the pineal gland at 0, 2, 12, 24, 36 and 48 hours after operation. Results Both CLOCK and BMAL levels in the pineal gland increased significantly 48 hours after HIBD compared with the sham-operated group ( P 0. 05 ) . Conclusions Levels of CLOCK and BMAL1 proteins in the pineal gland of rats increase significantly 48 hours after HIBD, suggesting that both CLOCK and BMAL1 may be involved the regulatory mechanism of circadian disorders in rats with HIBD.%目的 观察缺氧缺血性脑损伤(hypoxic-ischemic brain damage,HIBD)新生大鼠松果体中CLOCK、BMAL1蛋白表达的变化,探讨钟基因表达异常在HIBD导致的昼夜节律紊乱中的作用.方法 72只7日龄新生Sprague-Dawley大鼠随机分为假手术组与HIBD模型组,每组36只.采用改良Levine法建立HIBD模型,用Western blot方法测定两组新生大鼠术后0、2、12、24、36、48 h松果体中CLOCK、BMAL1蛋白水平.结果 HIBD模型组松果体的CLOCK及BMAL1蛋白表达水平在HIBD后48 h高于假手术组(P<0.05),在0、2、12、24、36 h CLOCK及BMAL1蛋白表达水平与假手术组相比差异均无统计学意义(P>0.05).结论 HIBD新生大鼠松果体中CLOCK和BMAL1蛋白在损伤48 h后有显著升高,提示两者可能共同参与缺氧缺血时昼夜节律紊乱的发生.

  13. In vitro evaluation of 213Bi-rituximab versus external gamma irradiation for the treatment of B-CLL patients: relative biological efficacy with respect to apoptosis induction and chromosomal damage

    International Nuclear Information System (INIS)

    External source radiotherapy and beta radioimmunotherapy (RIT) are effective treatments for lymphoid malignancies. The development of RIT with alpha emitters is attractive because of the high linear energy transfer (LET) and short path length, allowing higher tumour cell kill and lower toxicity to healthy tissues. We assessed the relative biological efficacy (RBE) of alpha RIT (in vitro) compared to external gamma irradiation with respect to induction of apoptosis in B chronic lymphocytic leukaemia (B-CLL) and induction of chromosomal damage in healthy donor B and T lymphocytes. The latter was measured by a micronucleus assay. 213Bi was eluted from a 225Ac generator and conjugated to CD20 antibody (rituximab) with CHX-A''-DTPA as a chelator. B-CLL cells from five patients were cultured for 24 h in RPMI/10% FCS while exposed to 213Bi conjugated to CD20 antibody or after external 60Co gamma irradiation. Binding assays were performed in samples of all patients to calculate the total absorbed dose. Apoptosis was scored by flow cytometric analyses of the cells stained with annexin V-FITC and 7-AAD. Apoptosis was expressed as % excess over spontaneous apoptosis in control. Full dose range experiments demonstrated 213Bi-conjugated CD20 antibody to be more effective than equivalent doses of external gamma irradiation, but showed that similar plateau values were reached at 10 Gy. The RBE for induction of apoptosis in B-CLL was 2 between 1.5 and 7 Gy. The micronucleus yield in lymphocytes of healthy volunteers was measured to assess the late toxicity caused by induction of chromosomal instability. While gamma radiation induced a steady increase in micronucleus yields in B and T cells, the damage induced by 213Bi was more dramatic, with RBE ranging from 5 to 2 between 0.1 Gy and 2 Gy respectively. In contrast to gamma irradiation, 213Bi inhibited mitogen-stimulated mitosis almost completely at 2 Gy. In conclusion, high-LET targeted alpha particle exposure killed B-CLL cells

  14. Biological and ecological characterization of two mites (Tetranychus Urticae and Phytoseiulus Persimilis) occurring in some agro-ecosystems; Caratterizzazione biologica ed ecologica di due acari (Tetranichus Urticae e Phytoseiulus Persimilis) interagenti in alcuni ecosistemi agrari

    Energy Technology Data Exchange (ETDEWEB)

    Calvitti, M. [ENEA, Centro Ricerche Casaccia, Roma (Italy). Dip. Innovazione

    1995-12-01

    This work is a brief review of the actual knowledge about biological and ecological characteristics of two species of mites: Tetranychus urticae Koch (Acarina Tetranychidae) (two-spotted spider mite) and the predaceous mite Phytoseiulus persimilis Athias Henriot (Acarina Phytoseiidae). Success obtained in biological control of spider mite, by mass release of P. persimilis, has increased the interest in biological and ecological study of these mites. Particularly, the following biological and ecological aspects of both P. persimilis and T. urticae are hereby discussed: reproductive biology; population dynamics (spider mites outbreaks) and natural regulation of the trophic interaction; feeding behaviour; biological control of two-spotted spider mite by P. persimilis. In this report experimental data obtained in laboratory have been integrated with bibliographic information concerning studies produced in natural conditions.

  15. Biological exposure limit in bone metabolism damage induced by co-exposure to fluorine and arsenic from coal burning%燃煤氟砷致骨代谢损伤的生物暴露限值初探

    Institute of Scientific and Technical Information of China (English)

    曾奇兵; 喻仙; 杨鋆; 洪峰

    2012-01-01

    Objective To study the biological exposure limit in bone metabolism damage caused by coexposure to fluorine and arsenic from coal burning in exposed population.Methods One hundred and ninety-eight cases of fluoride and arsenic co-exposed people from Liuchang village,Qinzhen city,Guizhou province were enrolled in the study.Urinary fluorine (UF),urinary arsenic (UAs),urinary hydroxyproline (UHYP),ross-linked Ntelopeptides of type Ⅰ collagen(UNTX) and bone strength index(STI) were detected.BMDS Version 2.1 software was used to calculate UF,UAs benchmark dose (BMD) and its lower confidence limit (BMDL) on the damage of bone metabolism caused by co-exposure to fluorine and arsenic from coal burning.Results The BMD and BMDL range of UF caused by co-exposure to fluorine and arsenic from coal burning were 0.68-1.35 mg/g Cr,0.57-1.11 mg/g Cr.The BMD and BMDL range of UAs caused by co-exposure to fluorine and arsenic from coal burning were 8.36-18.77 μg/g Cr,7.12-15.40 μg/g Cr.Conclusion The biological exposure limits of UF and UAs for bone metabolism toxicity are proposed as 0.57 mg/g Cr and 7.12 μg/g Cr in co-exposure to fluoride and arsenic from coal burning,respectively.%目的 探讨燃煤氟砷致暴露人群骨代谢损伤的生物暴露限值(BEL).方法 2009年选择贵州省清镇市流长乡198例氟砷联合暴露者作为调查对象,分别检测尿氟、尿砷及骨代谢效应标志尿羟脯氨酸(UHYP)和尿Ⅰ型胶原交联氨基末端肽(UNTX)、骨强度指数(STI).应用BMDS Version 2.1软件计算燃煤氟砷致骨代谢损伤的尿氟、尿砷基准剂量(BMD)及其可信限下限(BMDL).结果 氟、砷混合暴露引起骨代谢损伤的尿氟BMD及BMDL范围分别为0.68 ~ 1.35 mg/g Cr和0.57 ~ 1.11 mg/g Cr;尿砷BMD及BMDL范围分别为8.36 ~ 18.77 μg/g Cr和7.12 ~ 15.40 μg/g Cr.结论 建议燃煤氟砷混合暴露引起骨代谢损伤的生物暴露限值,尿氟为0.57 mg/g Cr,尿砷为7.12 μg/g Cr.

  16. 78 FR 66852 - Housing Assistance Due to Structural Damage

    Science.gov (United States)

    2013-11-07

    ... overall cap on financial assistance is $32,400 per declared event (78 FR 64523, Oct. 29, 2013)) on housing... Stafford Act that were made by the Post-Katrina Emergency Management Reform Act of 2006 (PKEMRA). DATES... the Federal Register, which revised its regulations implementing the IHP. See 67 FR 61446....

  17. 77 FR 44562 - Housing Assistance Due to Structural Damage

    Science.gov (United States)

    2012-07-30

    ... expectancy of more than 5 years, but less than 25 years. Housing with a life expectancy of less than 5 years... of housing that could be constructed. This type of housing would be that with a life expectancy of... Regulation Identifier Number (RIN) 1660-AA18, which revised its regulations implementing the IHP. See 67...

  18. Ductile damage parameters identification for cold metal forming applications

    OpenAIRE

    Bouchard, Pierre-Olivier; Gachet, Jean-Marie; Roux, Emile

    2011-01-01

    Ductile damage mechanics is essential to predict failure during cold metal forming applications. Several damage models can be found in the literature. These damage models are coupled with the mechanical behavior so as to model the progressive softening of the material due to damage growth. However, the identification of damage parameters remains an issue. In this paper, an inverse analysis approach is set-up to identify ductile damage parameters, based on different kind of mechanical tests an...

  19. Extension and validation of the Geant4 tool in the framework of the Geant-DNA project for the prediction of the radio-induced biological damages at the cellular scale

    International Nuclear Information System (INIS)

    A large experimental and modeling activity is currently taking place, aimed at better understanding the biological effects of ionizing radiation at the molecular scales. Considerable amounts of experimental data have been accumulated over the past decades in order to measure quantities such as macroscopic cellular survival curves and DNA strand damages after irradiation. In parallel, computer codes have been proposed to use a stochastic approach based on Monte Carlo technique to model physical interaction in the irradiated medium. The Geant4 tool-kit uses the object-oriented technology (C++) to describing particle-matter interactions, such as bio-medical physics and space physics, from sub-micrometer cells up to planetary scales. Geant4-DNA project is included in the Geant4 tool-kit and benefits from the easy accessibility of the Geant4 code for the development of a computing platform allowing estimation effects of ionizing radiations. In my thesis, firstly, I have contributed in the project the validation of various models with the experimental data collections extracted from the recent literature. A good agreement between total and differential cross section values corresponding to each available Geant4-DNA model and experimental data is validated by Kolmogorov-Smirnov testing. Secondly, I have improved elastic scattering process and working on the calculation of the DDCS for proton elastic scattering in water in the Geant4-DNA. In addition, I have combined Geant4 electromagnetic processes with the Geant4-DNA. This combination brought additional Geant4 simulation capabilities in complement of the possibility to combine Geant4-DNA models with other Geant4 electromagnetic models at different sizes and energy scales in a single simulation application. Finally, we have presented the usage of Geant4-DNA physics processes in Nano-meter-size targets fully implemented in a single Geant4 application. The frequencies of the deposited energy and number of direct DNA single

  20. Apple biological and physiological disorders in the orchard and in postharvest according to production system

    Directory of Open Access Journals (Sweden)

    Carlos Roberto Martins

    2013-03-01

    Full Text Available The study aimed to evaluate the incidence of biological and physiological disorders in the field and postharvested apples cvs. Gala, Fuji and Catarina grown in four production systems: conventional, organic transition, integrated and organic. Apples were evaluated for damages related to biological and physiological disorders in the orchard and after harvest. The greatest damages were attributed to pests, especially Anastrepha fraterculus in the organic system and Grapholita molesta in the organic transition. Apples produced in organic orchards had higher damage levels caused by postharvest physiological disorders than those grown in other production systems. For apples becoming from organic orchards most of the damage was due to lenticels breakdown and degeneration ('Gala', and bitter pit ('Fuji' and 'Catarina'. The incidence of postharvest rot was not influenced by apple production system.

  1. Damage Pattern as a Function of Various Types of Radiation

    Directory of Open Access Journals (Sweden)

    R.G. Ahmed

    2006-01-01

    Full Text Available The number of reports on the effects of various types of radiation is gradually increasing because of weakening of the immune system. Radiation can penetrate into living cells and result in the transfer of radiation energy to the biological material. The absorbed energy can increase the reactive oxygen species and break chemical bonds and cause ionization of different biologically essential macromolecules, such as DNA membrane lipids and proteins. Damage to the cellular membrane release the hydrolytic enzymes responsible for various catabolic processes in the tissues and leads to cell death. An understanding of the pattern in critical cellular structures such as DNA is an important prerequisite for a mechanistic assessment of primary radiation injury. The DNA damage induced by radiation such as base alterations, cross linking, strands breaker chromosomal aberration which may in turn lead to mutations. In order to further explore the harmful effects of radiation. I have produced a variety of effects of radiation on the apoptosis and necrosis. Indeed, the present review has shown that the increase in the oxidative stress (increased endogenous production of the free radicals due to radiation may be a reason for such a damage of the cell membrane, and may lead to harming the cellular elements (such as DNA. Here, one can hypothesize that, the cells with increased sensitivity to oxidative stress may be more susceptible to damage by radiation compared to normal cells. The ultimate biological consequences of this effect are subsequently processed by these cells. Much work remains to be done to firmly establish this concept.

  2. Optical sensor for heat conduction measurement in biological tissue

    Science.gov (United States)

    Gutierrez-Arroyo, A.; Sanchez-Perez, C.; Aleman-Garcia, N.

    2013-06-01

    This paper presents the design of a heat flux sensor using an optical fiber system to measure heat conduction in biological tissues. This optoelectronic device is based on the photothermal beam deflection of a laser beam travelling in an acrylic slab this deflection is measured with a fiber optic angle sensor. We measure heat conduction in biological samples with high repeatability and sensitivity enough to detect differences in tissues from three chicken organs. This technique could provide important information of vital organ function as well as the detect modifications due to degenerative diseases or physical damage caused by medications or therapies.

  3. Acute Myocardial Infarction Due To Electrical Injury

    OpenAIRE

    Uzkeser M et al.

    2011-01-01

    Rhythm abnormalities (conduction defects, tachycardia, and arrhythmia)due to electric shock are common. Rarely, myocardial infarction may beseen in these patients. This situation is generally caused by coronaryartery vasospasm and direct myocardial damage. In this report, wepresent a rare case of myocardial infarction due to electric shock.

  4. Development of radiation biological dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Chul Koo; Kim, Tae Hwan; Lee, Yun Sil; Son, Young Sook; Kim, Soo Kwan; Jang, Won Suk; Le, Sun Joo; Jee, Young Heun; Jung, Woo Jung

    1999-04-01

    Up until now, only a few methods have been developed for radiation biological dosimetry such as conventional chromosome aberration and micronucleus in peripheral blood cell. However, because these methods not only can be estimated by the expert, but also have a little limitation due to need high technique and many times in the case of radiation accident, it is very difficult to evaluate the absorbed dose of victims. Therefore, we should develop effective, easy, simple and rapid biodosimetry and its guideline (triage) to be able to be treated the victims as fast as possible. We established the premature chromosome condensation assay and apoptotic fragment assay which was the significant relationship between dose and cell damages to evaluate the irradiation dose as correct and rapid as possible using lymphocytes and crypt cells, and compared with conventional chromosome aberration assay and micronuclei assay.

  5. Development of radiation biological dosimetry

    International Nuclear Information System (INIS)

    Up until now, only a few methods have been developed for radiation biological dosimetry such as conventional chromosome aberration and micronucleus in peripheral blood cell. However, because these methods not only can be estimated by the expert, but also have a little limitation due to need high technique and many times in the case of radiation accident, it is very difficult to evaluate the absorbed dose of victims. Therefore, we should develop effective, easy, simple and rapid biodosimetry and its guideline (triage) to be able to be treated the victims as fast as possible. We established the premature chromosome condensation assay and apoptotic fragment assay which was the significant relationship between dose and cell damages to evaluate the irradiation dose as correct and rapid as possible using lymphocytes and crypt cells, and compared with conventional chromosome aberration assay and micronuclei assay

  6. On Damage Characterization of a Steel Sheet

    OpenAIRE

    Guzmán Inostroza, Carlos Felipe; Habraken, Anne

    2014-01-01

    Ductile damage is a physical phenomena which involves progressive deterioration of mechanical properties of metals, when undergoing high deformations. Compared to plasticity, the physical mechanisms behind damage are more complex and the microscale is not longer negligible. In mathematical damage models, founding an optimal set of material parameters can be a hard task due to the strong coupling and non-linearity of the equations. An identification strategy is then crucial to arrive to a gene...

  7. Biological Threats

    Science.gov (United States)

    ... Workplace Plans School Emergency Plans Main Content Biological Threats Biological agents are organisms or toxins that can ... for Disease Control and Prevention . Before a Biological Threat Unlike an explosion, a biological attack may or ...

  8. Material Induced Anisotropic Damage

    NARCIS (Netherlands)

    Niazi, M.S.; Wisselink, H.H.; Meinders, V.T.; Boogaard, van den A.H.; Hora, P.

    2012-01-01

    The anisotropy in damage can be driven by two different phenomena; anisotropic defor-mation state named Load Induced Anisotropic Damage (LIAD) and anisotropic (shape and/or distribution) second phase particles named Material Induced Anisotropic Damage (MIAD). Most anisotropic damage models are based

  9. Rapid Inventory of Earthquake Damage (RIED)

    NARCIS (Netherlands)

    Duque, Adriana; Hack, Robert; Montoya, Lorena; Scarpas, Tom; Slob, Siefko; Soeters, Rob; Westen, van Cees

    2001-01-01

    The 25 January 1999 Quindío earthquake in Colombia was a major disaster for the coffee-growing region in Colombia. Most of the damage occurred in the city of Armenia and surrounding villages. Damage due to earthquakes is strongly related to topographic and subsurface geotechnical conditions undernea

  10. Primary and oxidative DNA damage in salivary leukocytes as a tool for the evaluation of air pollution early biological effects in children: current status of the MAPEC (Monitoring Air Pollution Effects on Children for supporting public health policy study

    Directory of Open Access Journals (Sweden)

    Samuele Vannini

    2015-05-01

    Conclusions - The main objective of the MAPEC study is to evaluate the associations in children between air pollutants and early biological effects, and to propose a model for estimating the global genotoxic risk.

  11. DNA Damage Signals and Space Radiation Risk

    Science.gov (United States)

    Cucinotta, Francis A.

    2011-01-01

    Space radiation is comprised of high-energy and charge (HZE) nuclei and protons. The initial DNA damage from HZE nuclei is qualitatively different from X-rays or gamma rays due to the clustering of damage sites which increases their complexity. Clustering of DNA damage occurs on several scales. First there is clustering of single strand breaks (SSB), double strand breaks (DSB), and base damage within a few to several hundred base pairs (bp). A second form of damage clustering occurs on the scale of a few kbp where several DSB?s may be induced by single HZE nuclei. These forms of damage clusters do not occur at low to moderate doses of X-rays or gamma rays thus presenting new challenges to DNA repair systems. We review current knowledge of differences that occur in DNA repair pathways for different types of radiation and possible relationships to mutations, chromosomal aberrations and cancer risks.

  12. Insecticides and Biological Control

    Science.gov (United States)

    Furness, G. O.

    1972-01-01

    Use of insecticides has been questioned due to their harmful effects on edible items. Biological control of insects along with other effective practices for checking spread of parasites on crops are discussed. (PS)

  13. Perspective on the nuclear power plant accident caused by the great east Japan earthquake and tsunami. Health impairment risks due to pollution by radioactive materials from the damaged plant as recognized by experts and by the general population and role of the experts

    International Nuclear Information System (INIS)

    Large amounts of radioactive materials were leaked into the environment from the Fukushima Daiichi Nuclear Power Plant (FDNPP) of the Tokyo Electric Power Company damaged by the 2011 Great East Japan Earthquake and accompanying tsunami. Increased health impairment risks due to the leaked radioactive materials are of concern over a long period of time and over a wide geographical area. From the results of epidemiologic studies conducted after the Chernobyl accident, the health risks are not anticipated to be very marked. The purpose of the present study is to examine the elevated health risks as viewed by the general population, tolerance to the risks that the general population suffer from their viewpoint, and the overall picture as seen by researchers and experts in specialized areas of study after the accident. Information was obtained from articles in print and on the Internet and by interviewing a psychologist and tens of employees of several corporations. Epidemiologic studies conducted after the severe accident of the nuclear power plant in Chernobyl revealed an elevated risk of thyroid cancer in children due to 131I while elevated risks due to radioactive materials other than 131I were not detected. The amount of radioactive materials leaked into the environment from the FDNPP was less than that in Chernobyl. Therefore, it is possible to estimate that health impairment risks due to the leaked radioactive materials from the FDNPP are low. However, it is impossible to conclude a zero risk. It is likely that the general population does not fully understand the health impairment risks due to the leaked radioactive materials from the FDNPP. Although no increased incidences of diseases other than thyroid cancer of children were scientifically shown en masse from studies in Chernobyl, individual risks and results in the future caused by the severe accident of FDNPP cannot be denied. Much of the general population is apt to demand the security of a zero risk from

  14. Flood damage curves for consistent global risk assessments

    Science.gov (United States)

    de Moel, Hans; Huizinga, Jan; Szewczyk, Wojtek

    2016-04-01

    Assessing potential damage of flood events is an important component in flood risk management. Determining direct flood damage is commonly done using depth-damage curves, which denote the flood damage that would occur at specific water depths per asset or land-use class. Many countries around the world have developed flood damage models using such curves which are based on analysis of past flood events and/or on expert judgement. However, such damage curves are not available for all regions, which hampers damage assessments in those regions. Moreover, due to different methodologies employed for various damage models in different countries, damage assessments cannot be directly compared with each other, obstructing also supra-national flood damage assessments. To address these problems, a globally consistent dataset of depth-damage curves has been developed. This dataset contains damage curves depicting percent of damage as a function of water depth as well as maximum damage values for a variety of assets and land use classes (i.e. residential, commercial, agriculture). Based on an extensive literature survey concave damage curves have been developed for each continent, while differentiation in flood damage between countries is established by determining maximum damage values at the country scale. These maximum damage values are based on construction cost surveys from multinational construction companies, which provide a coherent set of detailed building cost data across dozens of countries. A consistent set of maximum flood damage values for all countries was computed using statistical regressions with socio-economic World Development Indicators from the World Bank. Further, based on insights from the literature survey, guidance is also given on how the damage curves and maximum damage values can be adjusted for specific local circumstances, such as urban vs. rural locations, use of specific building material, etc. This dataset can be used for consistent supra

  15. Synthetic biology: insights into biological computation.

    Science.gov (United States)

    Manzoni, Romilde; Urrios, Arturo; Velazquez-Garcia, Silvia; de Nadal, Eulàlia; Posas, Francesc

    2016-04-18

    Organisms have evolved a broad array of complex signaling mechanisms that allow them to survive in a wide range of environmental conditions. They are able to sense external inputs and produce an output response by computing the information. Synthetic biology attempts to rationally engineer biological systems in order to perform desired functions. Our increasing understanding of biological systems guides this rational design, while the huge background in electronics for building circuits defines the methodology. In this context, biocomputation is the branch of synthetic biology aimed at implementing artificial computational devices using engineered biological motifs as building blocks. Biocomputational devices are defined as biological systems that are able to integrate inputs and return outputs following pre-determined rules. Over the last decade the number of available synthetic engineered devices has increased exponentially; simple and complex circuits have been built in bacteria, yeast and mammalian cells. These devices can manage and store information, take decisions based on past and present inputs, and even convert a transient signal into a sustained response. The field is experiencing a fast growth and every day it is easier to implement more complex biological functions. This is mainly due to advances in in vitro DNA synthesis, new genome editing tools, novel molecular cloning techniques, continuously growing part libraries as well as other technological advances. This allows that digital computation can now be engineered and implemented in biological systems. Simple logic gates can be implemented and connected to perform novel desired functions or to better understand and redesign biological processes. Synthetic biological digital circuits could lead to new therapeutic approaches, as well as new and efficient ways to produce complex molecules such as antibiotics, bioplastics or biofuels. Biological computation not only provides possible biomedical and

  16. Synthetic biology: insights into biological computation.

    Science.gov (United States)

    Manzoni, Romilde; Urrios, Arturo; Velazquez-Garcia, Silvia; de Nadal, Eulàlia; Posas, Francesc

    2016-04-18

    Organisms have evolved a broad array of complex signaling mechanisms that allow them to survive in a wide range of environmental conditions. They are able to sense external inputs and produce an output response by computing the information. Synthetic biology attempts to rationally engineer biological systems in order to perform desired functions. Our increasing understanding of biological systems guides this rational design, while the huge background in electronics for building circuits defines the methodology. In this context, biocomputation is the branch of synthetic biology aimed at implementing artificial computational devices using engineered biological motifs as building blocks. Biocomputational devices are defined as biological systems that are able to integrate inputs and return outputs following pre-determined rules. Over the last decade the number of available synthetic engineered devices has increased exponentially; simple and complex circuits have been built in bacteria, yeast and mammalian cells. These devices can manage and store information, take decisions based on past and present inputs, and even convert a transient signal into a sustained response. The field is experiencing a fast growth and every day it is easier to implement more complex biological functions. This is mainly due to advances in in vitro DNA synthesis, new genome editing tools, novel molecular cloning techniques, continuously growing part libraries as well as other technological advances. This allows that digital computation can now be engineered and implemented in biological systems. Simple logic gates can be implemented and connected to perform novel desired functions or to better understand and redesign biological processes. Synthetic biological digital circuits could lead to new therapeutic approaches, as well as new and efficient ways to produce complex molecules such as antibiotics, bioplastics or biofuels. Biological computation not only provides possible biomedical and

  17. Radiation damage to DNA: the effect of LET

    Energy Technology Data Exchange (ETDEWEB)

    Ward, J.F.; Milligan, J.R. [California Univ., San Diego, La Jolla, CA (United States). School of Medicine

    1997-03-01

    Mechanisms whereby ionizing radiation induced damage are introduced into cellular DNA are discussed. The types of lesions induced are summarized and the rationale is presented which supports the statement that radiation induced singly damaged sites are biologically unimportant. The conclusion that multiply damaged sites are critical is discussed and the mechanisms whereby such lesions are formed are presented. Structures of multiply damaged sites are summarized and problems which they present to cellular repair systems are discussed. Lastly the effects of linear energy transfer on the complexity of multiply damaged sites are surveyed and the consequences of this increased complexity are considered in terms of cell survival and mutation. (author)

  18. Surface contamination initiated laser damage

    International Nuclear Information System (INIS)

    We are engaged in a comprehensive effort to understand and model the initiation and growth of laser damage initiated by surface contaminants. This includes, for example, the initial absorption by the contaminant, heating and plasma generation, pressure and thermal loading of the transparent substrate, and subsequent shockwave propagation, ''splashing'' of molten material and possible spallation, optical propagation and scattering, and treatment of material fracture. The integration use of large radiation hydrodynamics codes, optical propagation codes and material strength codes enables a comprehensive view of the damage process The following picture of surface contaminant initiated laser damage is emerging from our simulations. On the entrance optical surface, small particles can ablate nearly completely. In this case, only relatively weak shockwaves are launched into the substrate, but some particulate material may be left on the surface to act as a diffraction mask and cause further absorption. Diffraction by wavelength scale scattering centers can lead to significant intensity modulation. Larger particles will not be completely vaporized. The shockwave generated in this case 1642is larger and can lead to spallation of contaminant material which then may be deposited in the substrate. A gaseous atmosphere can lead to radiation trapping with concomitant increases in temperature and pressure near the surface. In addition, supersonic ionization waves in air may be generated which greatly extend the plasma plume spatially and temporally. Contaminants on the exit optical surface behave differently. They tend to heat and pop off completely in which case significant damage may not occur. Since plasma formed at the interface of the optic and absorbing particle is confined, much stronger pressures are generated in this case. Imaging of contaminants resulting in ''writing'' a diffraction pattern on the exit surface due to contamination on the entrance surface has been

  19. The CATDAT damaging earthquakes database

    Science.gov (United States)

    Daniell, J. E.; Khazai, B.; Wenzel, F.; Vervaeck, A.

    2011-08-01

    The global CATDAT damaging earthquakes and secondary effects (tsunami, fire, landslides, liquefaction and fault rupture) database was developed to validate, remove discrepancies, and expand greatly upon existing global databases; and to better understand the trends in vulnerability, exposure, and possible future impacts of such historic earthquakes. Lack of consistency and errors in other earthquake loss databases frequently cited and used in analyses was a major shortcoming in the view of the authors which needed to be improved upon. Over 17 000 sources of information have been utilised, primarily in the last few years, to present data from over 12 200 damaging earthquakes historically, with over 7000 earthquakes since 1900 examined and validated before insertion into the database. Each validated earthquake includes seismological information, building damage, ranges of social losses to account for varying sources (deaths, injuries, homeless, and affected), and economic losses (direct, indirect, aid, and insured). Globally, a slightly increasing trend in economic damage due to earthquakes is not consistent with the greatly increasing exposure. The 1923 Great Kanto (214 billion USD damage; 2011 HNDECI-adjusted dollars) compared to the 2011 Tohoku (>300 billion USD at time of writing), 2008 Sichuan and 1995 Kobe earthquakes show the increasing concern for economic loss in urban areas as the trend should be expected to increase. Many economic and social loss values not reported in existing databases have been collected. Historical GDP (Gross Domestic Product), exchange rate, wage information, population, HDI (Human Development Index), and insurance information have been collected globally to form comparisons. This catalogue is the largest known cross-checked global historic damaging earthquake database and should have far-reaching consequences for earthquake loss estimation, socio-economic analysis, and the global reinsurance field.

  20. The CATDAT damaging earthquakes database

    Directory of Open Access Journals (Sweden)

    J. E. Daniell

    2011-08-01

    Full Text Available The global CATDAT damaging earthquakes and secondary effects (tsunami, fire, landslides, liquefaction and fault rupture database was developed to validate, remove discrepancies, and expand greatly upon existing global databases; and to better understand the trends in vulnerability, exposure, and possible future impacts of such historic earthquakes.

    Lack of consistency and errors in other earthquake loss databases frequently cited and used in analyses was a major shortcoming in the view of the authors which needed to be improved upon.

    Over 17 000 sources of information have been utilised, primarily in the last few years, to present data from over 12 200 damaging earthquakes historically, with over 7000 earthquakes since 1900 examined and validated before insertion into the database. Each validated earthquake includes seismological information, building damage, ranges of social losses to account for varying sources (deaths, injuries, homeless, and affected, and economic losses (direct, indirect, aid, and insured.

    Globally, a slightly increasing trend in economic damage due to earthquakes is not consistent with the greatly increasing exposure. The 1923 Great Kanto ($214 billion USD damage; 2011 HNDECI-adjusted dollars compared to the 2011 Tohoku (>$300 billion USD at time of writing, 2008 Sichuan and 1995 Kobe earthquakes show the increasing concern for economic loss in urban areas as the trend should be expected to increase. Many economic and social loss values not reported in existing databases have been collected. Historical GDP (Gross Domestic Product, exchange rate, wage information, population, HDI (Human Development Index, and insurance information have been collected globally to form comparisons.

    This catalogue is the largest known cross-checked global historic damaging earthquake database and should have far-reaching consequences for earthquake loss estimation, socio-economic analysis, and the global

  1. Advanced concept for damage control : A framework to simulate fire propagation and damage control effects

    NARCIS (Netherlands)

    Gillis, M.P.W.; Keijer, W.; Smit, C.S.

    2003-01-01

    Current damage control procedures are developed on the basis of a long-standing experience. However there are reasons to believe that these procedures do not account for major weapon-induced calamities. Fire fighting after substantial blast and fragmentation damage, due to a weaponhit, is quite beyo

  2. The comparison of DNA damage induced by micro DBD plasma and low energy electron for curing human diseases

    Science.gov (United States)

    Park, Yeunsoo

    2015-09-01

    It is well known that low energy electrons (LEE, especially below 10 eV) can generate DNA damage via indirect action named dissociative electron attachment (DEA). We can now explain some parts of the exact mechanism on DNA damage by LEE collision with direct ionization effect when cancer patients get the radiotherapy. It is kind of remarkable information in the field of radiation therapy. However, it is practically very difficult to directly apply this finding to human disease cure due to difficulty of LEE therapy actualization and request of further clinical studies. Recently, there is a novel challenge in plasma application, that is, how we can apply plasma technology to diagnosis and treatment of many serious diseases like cancer. Cold atmospheric pressure plasma (CAPP) is a very good source to apply to plasma medicine and bio-applications because of low temperature, low cost, and easy handling. Some scientists have already reported good results related to clinical plasma application. The purposes of this study are to further find out exact mechanisms of DNA damage by LEE at the molecular level, to verify new DNA damage like structural alteration on DNA subunits and to compare DNA damage by LEE and plasma source. We will keep expanding our study to DNA damage by plasma source to develop plasma-based new medical and biological applications. We will show some recent results, DNA damage by LEE and non-thermal plasma.

  3. Evolutionary tradeoffs between economy and effectiveness in biological homeostasis systems.

    Directory of Open Access Journals (Sweden)

    Pablo Szekely

    Full Text Available Biological regulatory systems face a fundamental tradeoff: they must be effective but at the same time also economical. For example, regulatory systems that are designed to repair damage must be effective in reducing damage, but economical in not making too many repair proteins because making excessive proteins carries a fitness cost to the cell, called protein burden. In order to see how biological systems compromise between the two tasks of effectiveness and economy, we applied an approach from economics and engineering called Pareto optimality. This approach allows calculating the best-compromise systems that optimally combine the two tasks. We used a simple and general model for regulation, known as integral feedback, and showed that best-compromise systems have particular combinations of biochemical parameters that control the response rate and basal level. We find that the optimal systems fall on a curve in parameter space. Due to this feature, even if one is able to measure only a small fraction of the system's parameters, one can infer the rest. We applied this approach to estimate parameters in three biological systems: response to heat shock and response to DNA damage in bacteria, and calcium homeostasis in mammals.

  4. Damage Stability Assessment of an HSC after Grounding

    DEFF Research Database (Denmark)

    Ravn, Erik Sonne; Simonsen, Bo Cerup; Baatrup, Jan;

    2000-01-01

    Currently a substantial effort is done within the International Maritime Organisation (IMO) on revision of the High Speed Craft (HSC) Code. A main issue is the extent of bottom damage and raking damage due to grounding on hard rocks and the corresponding requirements to the damage stability...... of the vessel. It has been found that high-speed craft can experience a damage length up to 100% of the ship length. It has, however, also been argued that the damage stability requirements should reflect the size and probability of the damage with a reduction of the demand for the largest damages.......In the present paper a detailed grounding and damage stability analysis is carried out for two specific HSC, a mono-hull (86 m) and a catamaran (69 m). First various grounding scenarios are considered with different values of the forward speed and ground geometry. The results indicate that 100% bottom damage...

  5. DNA Damage Response

    OpenAIRE

    Giglia-Mari, Giuseppina; Zotter, Angelika; Vermeulen, Wim

    2011-01-01

    Structural changes to DNA severely affect its functions, such as replication and transcription, and play a major role in age-related diseases and cancer. A complicated and entangled network of DNA damage response (DDR) mechanisms, including multiple DNA repair pathways, damage tolerance processes, and cell-cycle checkpoints safeguard genomic integrity. Like transcription and replication, DDR is a chromatin-associated process that is generally tightly controlled in time and space. As DNA damag...

  6. Radiation damage to DNA: The importance of track structure

    CERN Document Server

    Hill, M A

    1999-01-01

    A wide variety of biological effects are induced by ionizing radiation, from cell death to mutations and carcinogenesis. The biological effectiveness is found to vary not only with the absorbed dose but also with the type of radiation and its energy, i.e., with the nature of radiation tracks. An overview is presented of some of the biological experiments using different qualities of radiation, which when compared with Monte Carlo track structure studies, have highlighted the importance of the localized spatial properties of stochastic energy deposition on the nanometer scale at or near DNA. The track structure leads to clustering of damage which may include DNA breaks, base damage etc., the complexity of the cluster and therefore its biological repairability varying with radiation type. The ability of individual tracks to produce clustered damage, and the subsequent biological response are important in the assessment of the risk associated with low-level human exposure. Recent experiments have also shown that...

  7. Simulated microgravity influenced the expression of DNA damage repair genes

    Science.gov (United States)

    Zhang, Meng; Sun, Yeqing; Jiawei, Liu; Wang, Ting

    2016-07-01

    Ionizing radiation and microgravity were considered to be the most important stress factors of space environmental the respective study of the biological effects of the radiation and microgravity carried out earlier, but the interaction of the effects of radiation with microgravity started later, and due to difference of the materials and methods the result of this experiment were not consistent. To further investigate the influence of microgravity on the expression of the radiation damage repair genes, the seed of Arabidopsis (Col) and its gravity-insensitive mutant (PIN2) were exposed to 0.1Gy of the dose of energetic carbon-ion beam radiation (LET = 30KeV / μm), and the germinated seed were than fixed in the 3D random positioning apparatus immediately for a 10-day simulated microgravity. By measuring the deflection angle of root tip and the changes of the expression of Ku70 and RAD51 protein, we investigated the impact of microgravity effect on radiation damage repair systems. The results shown that radiation, microgravity and microgravity with radiation could increase the angle of the root of the Col significantly, but no obvious effect on PIN2 type. The radiation could increase the expression of Ku70 significantly in both Col and PIN2, microgravity does not affect the expression, but the microgravity with radiation could decrease the expression of Ku70. This result shown that the microgravity could influence the radiation damage repair systems in molecular level. Moreover, our findings were important to understand the molecular mechanism of the impact of microgravity effect on radiation damage repair systems in vivo.

  8. Biological computation

    CERN Document Server

    Lamm, Ehud

    2011-01-01

    Introduction and Biological BackgroundBiological ComputationThe Influence of Biology on Mathematics-Historical ExamplesBiological IntroductionModels and Simulations Cellular Automata Biological BackgroundThe Game of Life General Definition of Cellular Automata One-Dimensional AutomataExamples of Cellular AutomataComparison with a Continuous Mathematical Model Computational UniversalitySelf-Replication Pseudo Code Evolutionary ComputationEvolutionary Biology and Evolutionary ComputationGenetic AlgorithmsExample ApplicationsAnalysis of the Behavior of Genetic AlgorithmsLamarckian Evolution Genet

  9. Fast x-ray fluorescence microtomography of hydrated biological samples.

    Directory of Open Access Journals (Sweden)

    Enzo Lombi

    Full Text Available Metals and metalloids play a key role in plant and other biological systems as some of them are essential to living organisms and all can be toxic at high concentrations. It is therefore important to understand how they are accumulated, complexed and transported within plants. In situ imaging of metal distribution at physiological relevant concentrations in highly hydrated biological systems is technically challenging. In the case of roots, this is mainly due to the possibility of artifacts arising during sample preparation such as cross sectioning. Synchrotron x-ray fluorescence microtomography has been used to obtain virtual cross sections of elemental distributions. However, traditionally this technique requires long data acquisition times. This has prohibited its application to highly hydrated biological samples which suffer both radiation damage and dehydration during extended analysis. However, recent advances in fast detectors coupled with powerful data acquisition approaches and suitable sample preparation methods can circumvent this problem. We demonstrate the heightened potential of this technique by imaging the distribution of nickel and zinc in hydrated plant roots. Although 3D tomography was still impeded by radiation damage, we successfully collected 2D tomograms of hydrated plant roots exposed to environmentally relevant metal concentrations for short periods of time. To our knowledge, this is the first published example of the possibilities offered by a new generation of fast fluorescence detectors to investigate metal and metalloid distribution in radiation-sensitive, biological samples.

  10. A Hypothesis on Biological Protection from Space Radiation Through the Use of New Therapeutic Gases

    Science.gov (United States)

    Schoenfeld, Michael P.; Ansari, Rafat R.; Nakao, Atsunori; Wink, David

    2011-01-01

    Radiation exposure to astronauts could be a significant obstacle for long duration manned space exploration because of current uncertainties regarding the extent of biological effects. Furthermore, concepts for protective shielding also pose a technically challenging issue due to the nature of cosmic radiation and current mass and power constraints with modern exploration technology. The concern regarding exposure to cosmic radiation is the biological damage it induces. As damage is associated with increased oxidative stress, it is important and would be enabling to mitigate and/or prevent oxidative stress prior to the development of clinical symptoms and disease. This paper hypothesizes a "systems biology" approach in which a combination of chemical and biological mitigation techniques are used conjunctively. It proposes using new, therapeutic, medical gases as both chemical radioprotectors for radical scavenging and biological signaling molecules for management of the body s response to exposure. From reviewing radiochemistry of water, biological effects of CO, H2, NO, and H2S gas, and mechanisms of radiation biology, it is concluded that this approach may have great therapeutic potential for radiation exposure. Furthermore, it also appears to have similar potential for curtailing the pathogenesis of other diseases in which oxidative stress has been implicated including cardiovascular disease, cancer, chronic inflammatory disease, hypertension, ischemia/reperfusion injury, acute respiratory distress syndrome, Parkinson s and Alzheimer s disease, cataracts, and aging.

  11. DNA DAMAGE QUANTITATION BY ALKALINE GEL ELECTROPHORESIS.

    Energy Technology Data Exchange (ETDEWEB)

    SUTHERLAND,B.M.; BENNETT,P.V.; SUTHERLAND, J.C.

    2004-03-24

    Physical and chemical agents in the environment, those used in clinical applications, or encountered during recreational exposures to sunlight, induce damages in DNA. Understanding the biological impact of these agents requires quantitation of the levels of such damages in laboratory test systems as well as in field or clinical samples. Alkaline gel electrophoresis provides a sensitive (down to {approx} a few lesions/5Mb), rapid method of direct quantitation of a wide variety of DNA damages in nanogram quantities of non-radioactive DNAs from laboratory, field, or clinical specimens, including higher plants and animals. This method stems from velocity sedimentation studies of DNA populations, and from the simple methods of agarose gel electrophoresis. Our laboratories have developed quantitative agarose gel methods, analytical descriptions of DNA migration during electrophoresis on agarose gels (1-6), and electronic imaging for accurate determinations of DNA mass (7-9). Although all these components improve sensitivity and throughput of large numbers of samples (7,8,10), a simple version using only standard molecular biology equipment allows routine analysis of DNA damages at moderate frequencies. We present here a description of the methods, as well as a brief description of the underlying principles, required for a simplified approach to quantitation of DNA damages by alkaline gel electrophoresis.

  12. Attitude of teenagers towards biology

    OpenAIRE

    Lavtižar, Teja

    2016-01-01

    ROSE project is a comprehensive study in which students' attitudes towards Science and Technology affected by many factors have been examined. In our study, only some aspects have been focused due to a narrower field of biology which has been interested in, and the direction of the attitude between Biology to elementary school students has been checked. The purpose of the master's work has been to determine the attitude of the teenagers to Biology as science and Biology as a school subjec...

  13. DNA damage response

    NARCIS (Netherlands)

    G. Giglia-Mari (Giuseppina); A. Zotter (Angelika); W. Vermeulen (Wim)

    2011-01-01

    textabstractStructural changes to DNA severely affect its functions, such as replication and transcription, and play a major role in age-related diseases and cancer. A complicated and entangled network ofDNA damage response (DDR) mechanisms, including multiple DNA repair pathways, damage tolerance p

  14. DNA damage and autophagy

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Rocha, Humberto; Garcia-Garcia, Aracely [Redox Biology Center and School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE 68583 (United States); Panayiotidis, Mihalis I. [School of Community Health Sciences, University of Nevada, Reno, NV 89557 (United States); Franco, Rodrigo, E-mail: rfrancocruz2@unl.edu [Redox Biology Center and School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, Lincoln, NE 68583 (United States)

    2011-06-03

    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.

  15. Neutron in biology

    Energy Technology Data Exchange (ETDEWEB)

    Niimura, Nobuo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-11-01

    Neutron in biology can provide an experimental method of directly locating relationship of proteins and DNA. However, there are relatively few experimental study of such objects since it takes a lot of time to collect a sufficient number of Bragg reflections and inelastic spectra due to the low flux of neutron illuminating the sample. Since a next generation neutron source of JAERI will be 5MW spallation neutron source and its effective neutron flux will be 10{sup 2} to 10{sup 3} times higher than the one of JRR-3M, neutron in biology will open a completely new world for structural biology. (author)

  16. Morphological and physiological damages of the mycorrhiza-root-system of the beech, due to soil contamination and possibilities of regeneration. Morphologische und physiologische Schaedigungen des Mykorrhiza-Wurzel-Systems bei der Buche als Folge von Bodenbelastungen und Moeglichkeiten der Regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Heumann, H.G.; Hofmann, H.P.; Kubach, D.; Linert, U.

    1989-08-01

    Field and laboratory examinations were carried out in order to find out whether mycorrhizae of beeches are damaged by acid deposits or experimental changes of the substrate. The examined samples of mycorrhizae collected from areas of severely damaged beeches and from areas of undamaged beeches showed no significant correlation to the visible damage of trees in respect to frequency, vitality or structural organization. Laboratory experiments for artificial mycorrhizal formation of beech seedlings with Cenococcum geophilum in sloping plastic plate cultures and in a vermiculite/peat/sand substrate were successful. Metal treatments reduced shoot and root weights, whereby copper and nickel effected the mycorrhizal seedlings more than the non-mycorrhizal ones. Cytological examinations revealed that in the damaged plants cortical root cells are often destroyed by intracellular infections of C. geophilum. Our findings show that the positive effect of ectomycorrhizae on metal tolerance of trees cannot be generalized with respect to either metal, or fungal symbiont. (orig.) With 34 refs., 8 tabs., 62 figs.

  17. Exogenous glycosaminoglycans coat damaged bladder surfaces in experimentally damaged mouse bladder

    Directory of Open Access Journals (Sweden)

    Hurst Robert E

    2005-03-01

    Full Text Available Abstract Background Interstital cystitis is often treated with exogenous glycosaminoglycans such as heparin, chondroitin sulphate (Uracyst, hyaluronate (Cystistat or the semi-synthetic pentosan polysulphate (Elmiron. The mechanism of action is presumed to be due to a coating of the bladder surface to replace the normally present chondroitin sulphate and heparan sulphate lost as a result of the disease. This study used fluorescent labelled chondroitin sulphate to track the distribution of glycosaminoglycans administered intravesically to mouse bladder that had been damaged on the surface. Methods The surfaces of mouse bladders were damaged by 3 mechanisms – trypsin, 10 mM HCl, and protamine sulphate. Texas Red-labeled chondroitin sulphate was instilled into the bladders of animals with damaged bladders and controls instilled only with saline. Bladders were harvested, frozen, and sectioned for examination by fluorescence. Results The normal mouse bladder bound a very thin layer of the labelled chondroitin sulphate on the luminal surface. Trypsin- and HCl-damaged bladders bound the labelled chondroitin sulphate extensively on the surface with little penetration into the bladder muscle. Protamine produced less overt damage, and much less labelling was seen, presumably due to loss of the label as it complexed with the protamine intercalated into the bladder surface. Conclusion Glycosaminoglycan administered intravesically does bind to damaged bladder. Given that the changes seen following bladder damage resemble those seen naturally in interstitial cystitis, the mechanisms proposed for the action of these agents is consistent with a coating of damaged bladder.

  18. Alpha particle induced DNA damage and repair in normal cultured thyrocytes of different proliferation status

    Energy Technology Data Exchange (ETDEWEB)

    Lyckesvärd, Madeleine Nordén, E-mail: madeleine.lyckesvard@oncology.gu.se [Department of Oncology, Sahlgrenska Academy, University of Gothenburg (Sweden); Delle, Ulla; Kahu, Helena [Department of Oncology, Sahlgrenska Academy, University of Gothenburg (Sweden); Lindegren, Sture [Department of Radiation Physics, Sahlgrenska Academy, University of Gothenburg (Sweden); Jensen, Holger [The PET and Cyclotron Unit Copenhagen University Hospital, Rigshospitalet (Denmark); Bäck, Tom [Department of Radiation Physics, Sahlgrenska Academy, University of Gothenburg (Sweden); Swanpalmer, John [Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg (Sweden); Elmroth, Kecke [Department of Oncology, Sahlgrenska Academy, University of Gothenburg (Sweden)

    2014-07-15

    Highlights: • We study DNA damage response to low-LET photons and high-LET alpha particles. • Cycling primary thyrocytes are more sensitive to radiation than stationary cells. • Influence of radiation quality varies due to cell cycle status of normal cells. • High-LET radiation gives rise to a sustained DNA damage response. - Abstract: Childhood exposure to ionizing radiation increases the risk of developing thyroid cancer later in life and this is suggested to be due to higher proliferation of the young thyroid. The interest of using high-LET alpha particles from Astatine-211 ({sup 211}At), concentrated in the thyroid by the same mechanism as {sup 131}I [1], in cancer treatment has increased during recent years because of its high efficiency in inducing biological damage and beneficial dose distribution when compared to low-LET radiation. Most knowledge of the DNA damage response in thyroid is from studies using low-LET irradiation and much less is known of high-LET irradiation. In this paper we investigated the DNA damage response and biological consequences to photons from Cobolt-60 ({sup 60}Co) and alpha particles from {sup 211}At in normal primary thyrocytes of different cell cycle status. For both radiation qualities the intensity levels of γH2AX decreased during the first 24 h in both cycling and stationary cultures and complete repair was seen in all cultures but cycling cells exposed to {sup 211}At. Compared to stationary cells alpha particles were more harmful for cycling cultures, an effect also seen at the pChk2 levels. Increasing ratios of micronuclei per cell nuclei were seen up to 1 Gy {sup 211}At. We found that primary thyrocytes were much more sensitive to alpha particle exposure compared with low-LET photons. Calculations of the relative biological effectiveness yielded higher RBE for cycling cells compared with stationary cultures at a modest level of damage, clearly demonstrating that cell cycle status influences the relative

  19. 固液耦合模式下含断层缺陷煤层回采诱发底板损伤及断层活化突水机制研究%Mechanism of water inrush due to damage of floor and fault activation induced by mining coal seam with fault defects under fluid-solid coupling mode

    Institute of Scientific and Technical Information of China (English)

    张培森; 颜伟; 张文泉; SHEN Baotang; 王浩

    2016-01-01

    针对具体地质条件,以现场试验数据为基础,采用相似材料试验及数值模拟相结合的分析方法,对含断层缺陷煤层回采过程中底板损伤破坏及断层活化规律进行研究,研究得出:采用内径不同的水管能够很好地反映底板岩层渗透性的空间差异性,通过采用调节注水管水柱高度的方式可以控制水压以满足设计要求;煤层埋深、承压水水压及断层落差越大越易突水,断层防水煤柱宽度越大越不易突水;通过试验及模拟计算再现了不同因素影响下煤层回采过程中底板采动裂隙形成、断层活化到突水通道形成的全过程,揭示了含断层构造底板突水通道的形成机制;研究结果对承压水上含断层缺陷煤层回采时防水煤柱的留设具有重要的参考价值。%Based on the field test data, the damage and fracturing of the mine floor and the pattern of fault activation during the backstopping of the working face are evaluated by the combined method of similar material tests and numerical simulations. Some conclusions are drawn that the spatial differences of the permeability of the rock stratum floor can be simulated by water pipes with different inner diameters;the water pressure can be modulated by adjusting the height of the water column in the water pipe to meet the design requirements;a higher burial depth of the coal stratum, confined water pressure and throw of the fault promote more chances for water-inrush, while a larger width of the water-resistant coal pillar at the fault helps avoid water-inrush events; and the physical tests and numerical calculations are used to simulate the complete process of the formation of cracks at the floor due to mining, fault activation and formation of water-inrush channel during backstopping, and the mechanism of formation of the water-inrush channel at the floor fault structure is revealed. The conclusions provide significant references for the

  20. Characterisation of the histone methyltransferase SET8 in cell cycle progression and the DNA damage response

    DEFF Research Database (Denmark)

    Jørgensen, Stine

    2008-01-01

    Histone modifications and their catalysing enzymes have within the last few years proven to be essential players in many biological processes. Due to their ability to modulate chromatin structure and affect signalling pathways they are found to affect diverse processes such as transcription, DNA...... recombination and repair. I therefore initiated a mass spectrometry based study to identify changes in histone modifications after DNA damage. By using SILAC labelling of cells to quantatively measure the changes in histone modifications, we observed a marked reduction in the level of monomethylated Histone H4...... lysine 20 (H4K20me1) after damage. H4K20me1 is catalysed by the histone methyltransferase SET8 (aka PR-SET7), and functional studies of this enzyme revealed that SET8 is important for S phase progression. We also showed that depletion of SET8 in several different cancer cell lines results in accumulation...

  1. Natural resource damage assessments: The second generation

    International Nuclear Information System (INIS)

    The Damage Assessment Regulations Team (DART), Office of General Counsel, National Oceanic and Atmospheric Administration (NOAA), has focused on developing natural resource damage assessment regulations for oil pollution in navigable waters. These procedures may lower the transaction costs of assessments, encourage joint cooperative assessments, simplify most assessments and provide technical guidance for conducting assessments. DART is developing regulations for the assessment of damages due to injuries related to oil spills under the Oil pollution Act of 1990. These regulations will involve coordination, restoration and economic valuation. NOAA encourages federal, state, tribal and foreign trustees, to develop prespill plans. Coordination with response agencies assures protection of important natural resources. The regulations provide an open record, which becomes the basis for judicial review. Various methods being developed to assess damages for injuries to natural resources include: compensation formulas for spills under 50,000 gallons of oil, the Type A model, expedited damage assessment (EDA) procedures, and comprehensive damage assessment (CDA) procedures which can be used for spills of various sizes. These procedures provide trustees with a choice for assessing natural resource damages to each oil spill. NOAA is emphasizing the importance of restoration. Restoration plans will define project goals and objectives, establish procedures and methods for site restoration, and define the approach based on sound science. Finally, numerous economic methods are identified to calculate the lost or diminished use as passive use of the affected resources

  2. Onycholysis due to trauma

    Directory of Open Access Journals (Sweden)

    Patricia Chang

    2014-04-01

    Full Text Available Female patient, 35 years old who came to the private office due to discoloration of her left thumbnail and little pain since 1 month ago. Clinical examination shows nail disease on her left thumbnail with onycholysis and dyschromia, dermatoscopy showed white-yellowish discoloration (Fig. 1A, B. The rest of the clinical examination was normal. Patient use to using acrylic nails since 2 years ago and denied some trauma at the nail. The diagnosis of onycholysis due to trauma was done and recommended her not to use acrylic nail, maintain the nail short and avoid wetness.

  3. 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)

  4. 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 ...

  5. Bypassing damaged nervous tissue

    CERN Document Server

    Shneider, M N

    2016-01-01

    We show the principal ability of bypassing damaged demyelinated portions of nervous tissue, thereby restoring its normal function for the passage of action potentials. We carry out a theoretical analysis on the basis of the synchronization mechanism of action potential propagation along a bundle of neurons, proposed recently in [1]. And we discuss the feasibility of implement a bypass to restore damaged nervous tissue and creating an artificial neuron network.

  6. Modelling the induction of cell death and chromosome damage by therapeutic protons

    CERN Document Server

    Carante, M P

    2015-01-01

    A two-parameter biophysical model cal led BIANCA (BIophysical ANalysis of Cell death and chromosome Aberrations), which assumes a pivotal role for DNA cluster damage and for “lethal” chromosome aberrations, was applied to calculate cell death and chromosome aberrations for normal and radio-resistant cells along a 62-MeV eye melanoma proton beam. The yield of DNA “Cluster Lesions” and the probability for a chromosome fragment of not being rejoined with any partne r were adjustable parameters. In line with other works, the beam effectiveness at inducing both biological endpoints was found to increase with increasing depth, and high levels of damage were found also beyond the dose fall-off, due to the higher biological effectiveness of low-energy protons. This implies that assuming a constant RBE along the whole SOBP, as is currently done in clinical practice, may be sub-optimal, also implying a possible underestimation of normal tissue damage. Furthermore, the calculations suggested that fo...

  7. Astragalus Injection for Hypertensive Renal Damage: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Tian Sun

    2012-01-01

    Full Text Available Objective. To evaluate the effectiveness of astragalus injection (a traditional Chinese patent medicine for patients with renal damage induced by hypertension according to the available evidence. Methods. We searched MEDLINE, China National Knowledge Infrastructure (CNKI, Chinese VIP Information, China Biology Medicine (CBM, and Chinese Medical Citation Index (CMCI, and the date of search starts from the first of database to August 2011. No language restriction was applied. We included randomized controlled trials testing astragalus injection against placebo or astragalus injection plus antihypertensive drugs against antihypertensive drugs. Study selection, data extraction, quality assessment, and data analyses were conducted according to the Cochrane review standards. Results. 5 randomized trials (involving 429 patients were included and the methodological quality was evaluated as generally low. The pooled results showed that astragalus injection was more effective in lowering β2-microglobulin (β2-MG, microalbuminuria (mAlb compared with placebo, and it was also superior to prostaglandin in lowering blood urea nitrogen (BUN, creatinine clearance rate (Ccr. There were no adverse effects reported in the trials from astragalus injection. Conclusions. Astragalus injection showed protective effects in hypertensive renal damage patients, although available studies are not adequate to draw a definite conclusion due to low quality of included trials. More rigorous clinical trials with high quality are warranted to give high level of evidence.

  8. Estimative of core damage frequency in IPEN IEA-R1 research reactor due to the initiating events of loss of flow caused by channel blockage and loss of coolant caused by a large rupture in the pipe of the primary circuit - PSA level 1

    Energy Technology Data Exchange (ETDEWEB)

    Hirata, Daniel Massami [Centro Tecnologico da Marinha em Sao Paulo (CTMSP), Sao Paulo, SP (Brazil); Sabundjian, Gaiane, E-mail: gdjian@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP) Sao Paulo, SP (Brazil)

    2011-07-01

    This work applies the methodology of Probabilistic Safety Assessment Level 1 to the research reactor IEA-R1 IPEN-CNEN/SP. Two categories of identified initiating events of accidents in the reactor are studied: loss of flow and loss of primary coolant. Among the initiating events, blockage of flow channel and loss of cooling fluid caused by large pipe rupture in the primary circuit are chosen for a detailed analysis. The event tree technique is used to analyze the evolution of the accident, including the actuation or the fail of actuation of the safety systems and the reactor damages. Using the fault tree the reliability of the following reactor safety systems is evaluated: reactor shutdown system, isolation of the reactor pool, Emergency Core Cooling System (ECCS) and the electric system. Estimative for the frequency of damage to the reactor core and the probability of failure of the analyzed systems are calculated. The estimated values for the frequencies of core damage are within the expected margins and are of the same order of magnitude as those found for similar reactors. The reliability of the reactor shutdown system, isolation of the reactor pool and ECCS are satisfactory for the conditions in which these systems are required. However, for the electric system it is suggested an upgrade to increase its reliability. (author)

  9. Biological effects of mutagenic agents

    International Nuclear Information System (INIS)

    There is an increasing body of evidence that mutagenic agents (biological, chemical and physical) play an important role in the etiology of human diseases. Mutations may occur in the germinal as well as in the somatic cells. Mutations of the germ cells may result on infertility or fertilization of damaged cells, the later leading to abortion or birth of a malformed fetus. Somatic-cells mutations may have various biological effects, depending on the period of the human life at which the mutation occurs. If it occurs during the prenatal life, a teratogenic or carcinogenic effect will be observed. If the somatic cell is damaged during the postnatal life, this will lead to neoplastic transformation. Therefore it is extremely important to know the mutagenic, teratogenic and carcinogenic effects of various biological, chemical and physical agents in order to eliminate them from our environment. (author). 13 refs, 4 figs, 1 tab

  10. Damage Detection for Long-Span Cable-Stayed Bridge

    Institute of Scientific and Technical Information of China (English)

    Zhao Ling; Li Aiqun; Miao Changqing; Wang Yonglan

    2006-01-01

    Based on the updated finite-element model of a cable-stayed bridge, this study investigates the technique of identifying damage existing in cable or girder by means of numerical simulation. The modal analysis is performed to identify the changes in modal frequencies and curvatures caused by damage, and the static analysis is executed to detect the influence of damage on cable force. The results indicate a relatively significant decrease in frequencies of lower vertical bending modes due to the damage in cable and little change of frequencies due to damage in girder. Different sensitivities to the location of damaged cable are observed from the frequency changes of different bending modes, which can be used to initially locate the damaged cable. The damage in either cable or girder can be further localized by the most significant change in curvature of girder. The damage occurred in a cable produces a remarkable change in force of nearby cables, whereas the damage in girder brings little change of cable forces. In addition, a pragmatic approach for localizing the damage in girder or cable is proposed based on a comprehensive utilization of the changes in frequency of vertical bending modes, modal curvature of girder, and force in cables.

  11. Is synthetic biology mechanical biology?

    Science.gov (United States)

    Holm, Sune

    2015-12-01

    A widespread and influential characterization of synthetic biology emphasizes that synthetic biology is the application of engineering principles to living systems. Furthermore, there is a strong tendency to express the engineering approach to organisms in terms of what seems to be an ontological claim: organisms are machines. In the paper I investigate the ontological and heuristic significance of the machine analogy in synthetic biology. I argue that the use of the machine analogy and the aim of producing rationally designed organisms does not necessarily imply a commitment to mechanical biology. The ideal of applying engineering principles to biology is best understood as expressing recognition of the machine-unlikeness of natural organisms and the limits of human cognition. The paper suggests an interpretation of the identification of organisms with machines in synthetic biology according to which it expresses a strategy for representing, understanding, and constructing living systems that are more machine-like than natural organisms.

  12. Enediyne anticancer antibiotic lidamycin: chemistry, biology and pharmacology.

    Science.gov (United States)

    Shao, Rong-guang; Zhen, Yong-su

    2008-02-01

    The enediyne antibiotics, the potent anticancer agents that contain diyne-ene functional groups, are appreciated for their novel molecular architecture, their remarkable biological activity and their fascinating mechanism of action. Their anticancer activity is apparently due to their ability to damage DNA through radical-mediated hydrogen abstraction. The enediyne antibiotics show markedly cytotoxicities against cancers in vitro and in vivo. Lidamycin is a member of the enediyne anticancer antibiotic family. This review examines lidamycin with particular emphasis on the discovery, the biological properties and its structure-activity relationships. In addition, the possible mechanisms of action of lidamycin are described. Recent progress, particularly in the areas of biosynthesis, and immunoconjugates are highlighted. Finally, the pharmacological applications of lidamycin in cancer therapy and its potential use as anticancer agents are also discussed. PMID:18288918

  13. Biology Notes.

    Science.gov (United States)

    School Science Review, 1982

    1982-01-01

    Presents procedures, exercises, demonstrations, and information on a variety of biology topics including labeling systems, biological indicators of stream pollution, growth of lichens, reproductive capacity of bulbous buttercups, a straw balance to measure transpiration, interaction of fungi, osmosis, and nitrogen fixation and crop production. (DC)

  14. VIBRATION ANALYSIS ON A COMPOSITE BEAM TO IDENTIFY DAMAGE AND DAMAGE SEVERITY USING FINITE ELEMENT METHOD

    Directory of Open Access Journals (Sweden)

    E.V.V.Ramanamurthy

    2011-07-01

    Full Text Available The objective of this paper is to develop a damage detection method in a composite cantilever beam with an edge crack has been studied using finite element method. A number of analytical, numerical andexperimental techniques are available for the study of damage identification in beams. Studies were carried out for three different types of analysis on a composite cantilever beam with an edge crack as damage. The material used in this analysis is glass-epoxy composite material. The finite element formulation was carried out in the analysis section of the package, known as ANSYS. The types of vibration analysis studied on a composite beam are Modal, Harmonic andTransient analysis. The crack is modeled such that the cantilever beam is replaced with two intact beams with the crack as additional boundary condition. Damage algorithms are used to identify and locate the damage. Damage index method is also used to find the severity of the damage. The results obtained from modal analysis were compared with the transient analysis results.The vibration-based damage detection methods are based on the fact that changes of physical properties (stiffness, mass and damping due to damage will manifest themselves as changes in the structural modal parameters (natural frequencies, mode shapes and modal damping. The task is then to monitor the selected indicators derived from modal parameters to distinguish between undamaged and damaged states. However, the quantitative changes of global modal parameters are not sufficiently sensitive to a local damage. The proposed approach, on the other hand, interprets the dynamic changes caused by damage in a different way. Although the basis for vibration-based damage detection appears intuitive, the implementation in real structures may encounter many significant challenges. The most fundamental issue is the fact that damage typically is a local phenomenon and may not dramatically influence the global dynamic response of a

  15. 7 CFR 1488.11 - Liquidated damages.

    Science.gov (United States)

    2010-01-01

    .... Liquidated damages shall not be assessed: Under paragraph (a) of this section if the Assistant Sales manager... (b) of this section if the Assistant Sales Manager determines that failure to export was due to loss... under paragraph (c) of this section if the Assistant Sales Manager determines that failure to enter...

  16. Integrated geomechanical modelling for deep subsurface damage

    NARCIS (Netherlands)

    Wees, J.D. van; Orlic, B.; Zijl, W.; Jongerius, P.; Schreppers, G.J.; Hendriks, M.

    2001-01-01

    Government, E&P and mining industry increasingly demand fundamental insight and accurate predictions on subsurface and surface deformation and damage due to exploitation of subsurface natural resources, and subsurface storage of energy residues (e.g. CO2). At this moment deformation is difficult to

  17. PATHOGENETIC MECHANISMS OF THE DEVELOPMENT OF ISCHEMIC AND REPERFUSION DAMAGE THE KIDNEYS AS A PROMISING TARGET SPECIFIC THERAPY

    Directory of Open Access Journals (Sweden)

    A. V. Vatazin

    2015-01-01

    Full Text Available Ischemic and reperfusion injury is a complex, multifactorial process that damage kidney transplant. Knowledge and understanding of pathogenic mechanisms of damage processes allows the use of various biological agents to reduce this damage. However, the application of most of biological agents is still only in the experiment. The purpose of this survey show participants of pathogenetic mechanisms, mainly inflammatory mediators (cytokines, chemokines, their interactions, and the consequences of their damaging effects on the fabric kidney transplant. 

  18. Introduction to radiation biology

    International Nuclear Information System (INIS)

    This book is arranged in a logical sequence, starting from radiation physics and radiation chemistry, followed by molecular, subcellular and cellular effects and going on to the level of organism. Topics covered include applied radiobiology like modifiers of radiosensitivity, predictive assay, health physics, human genetics and radiopharmaceuticals. The topics covered are : 1. Radiation Physics, 2. Detection and Measurement of Radiation, 3. Radiation Chemistry, 4. DNA Damage and Repair, 5. Chromosomal Aberrations and Gene Mutations, 6. Cellular Radiobiology 7. Acute Radiation Effects, 8. Delayed Effects of Radiation, 9. Biological Basis of Radiotherapy, 10. Chemical Modifiers of Radiosensitivity, 11. Hyperthermia, 12. High LET Radiations in Cancer, Therapy, 13. Predictive Assays, 14. Radiation Effects on Embryos, 15. Human Radiation Genetics, 16. Radiolabelled Compounds in Biology and Medicine and 17. Radiological Health

  19. Radiation damage to nucleoprotein complexes in macromolecular crystallography

    Energy Technology Data Exchange (ETDEWEB)

    Bury, Charles; Garman, Elspeth F.; Ginn, Helen Mary [University of Oxford, South Parks Road, Oxford OX1 3QU (United Kingdom); Ravelli, Raimond B. G. [Maastricht University, PO Box 616, Maastricht 6200 MD (Netherlands); Carmichael, Ian [University of Notre Dame, Notre Dame, IN 46556 (United States); Kneale, Geoff; McGeehan, John E., E-mail: john.mcgeehan@port.ac.uk [University of Portsmouth, King Henry 1st Street, Portsmouth PO1 2DY (United Kingdom)

    2015-01-30

    Quantitative X-ray induced radiation damage studies employing a model protein–DNA complex revealed a striking partition of damage sites. The DNA component was observed to be far more resistant to specific damage compared with the protein. Significant progress has been made in macromolecular crystallography over recent years in both the understanding and mitigation of X-ray induced radiation damage when collecting diffraction data from crystalline proteins. In contrast, despite the large field that is productively engaged in the study of radiation chemistry of nucleic acids, particularly of DNA, there are currently very few X-ray crystallographic studies on radiation damage mechanisms in nucleic acids. Quantitative comparison of damage to protein and DNA crystals separately is challenging, but many of the issues are circumvented by studying pre-formed biological nucleoprotein complexes where direct comparison of each component can be made under the same controlled conditions. Here a model protein–DNA complex C.Esp1396I is employed to investigate specific damage mechanisms for protein and DNA in a biologically relevant complex over a large dose range (2.07–44.63 MGy). In order to allow a quantitative analysis of radiation damage sites from a complex series of macromolecular diffraction data, a computational method has been developed that is generally applicable to the field. Typical specific damage was observed for both the protein on particular amino acids and for the DNA on, for example, the cleavage of base-sugar N{sub 1}—C and sugar-phosphate C—O bonds. Strikingly the DNA component was determined to be far more resistant to specific damage than the protein for the investigated dose range. At low doses the protein was observed to be susceptible to radiation damage while the DNA was far more resistant, damage only being observed at significantly higher doses.

  20. Helium vs. Proton Induced Displacement Damage in Electronic Materials

    Science.gov (United States)

    Ringo, Sawnese; Barghouty, A. F.

    2010-01-01

    In this project, the specific effects of displacement damage due to the passage of protons and helium nuclei on some typical electronic materials will be evaluated and contrasted. As the electronic material absorbs the energetic proton and helium momentum, degradation of performance occurs, eventually leading to overall failure. Helium nuclei traveling at the same speed as protons are expected to impart more to the material displacement damage; due to the larger mass, and thus momentum, of helium nuclei compared to protons. Damage due to displacement of atoms in their crystalline structure can change the physical properties and hence performance of the electronic materials.

  1. Análise matemática e biológica dos modelos de estimativa de perdas de rendimento na cultura devido à interferência de plantas daninhas Mathematical and biological analysis of the models for estimating culture yield losses due to weed interference

    Directory of Open Access Journals (Sweden)

    C. Adati

    2006-01-01

    Full Text Available As plantas daninhas acarretam reduções no rendimento das culturas agrícolas. Os modelos matemáticos de estimativa de perda de rendimento na cultura devido à interferência dessas plantas podem ser instrumentos úteis à tomada de decisão de manejo. Se for possível prever as perdas de rendimento, será possível decidir se é viável ou não a aplicação de uma medida de controle. Há na literatura vários modelos matemáticos empíricos de regressão lineares, não-lineares e polinomiais usados para estimar as perdas de rendimento devido às plantas daninhas. O presente trabalho teve como objetivo apresentar uma análise dos modelos matemáticos presentes na literatura utilizados para estimar as perdas de rendimento que as plantas daninhas acarretam à cultura, considerando o ajuste matemático às observações e a descrição biológica do comportamento dessas perdas.The presence of weeds in any production system involving plants causes crop yield losses. Mathematical models for crop yield loss estimation due to the interference of weeds can be useful tools for decision-making management strategies. If it is possible to predict crop yield loss, it will be possible to decide whether it is viable to apply control measures. There are several empirical models in the literature used to estimate crop yield loss due to the presence of weeds, which are linear, non linear and polynomial. The goal of this work is to present an analysis of the existing mathematical models used to estimate crop yield loss due to weeds by considering both their mathematical fit and biological behavior.

  2. The second generation of natural resource damage assessments: Lessons learned?

    International Nuclear Information System (INIS)

    The Damage Assessment Regulations Team (DART), under the Office of General Counsel of the National Oceanic and Atmospheric Administration (NOAA), has centered its efforts on developing natural resource damage assessment regulations for oil pollution in navigable waters. These procedures will likely lower the costs associated with damage assessments, encourage joint cooperative assessments and simplify most assessments. The DART team of NOAA is developing new regulations for the assessment of damages due to injuries related to oil spills under the Oil Pollution Act of 1990. These regulations will involve coordination, restoration, and economic valuation. Various methods are currently being developed to assess damages for injuries to natural resources. The proposed means include: compensation tables for spills under 50,000 gallons, Type A model, expedited damage assessment (EDA) procedures, and comprehensive procedures. They are being developed to provide trustees with a choice for assessing natural resource damages for each oil spill

  3. Crumpling Damaged Graphene

    CERN Document Server

    Giordanelli, I; Andrade,, J S; Gomes, M A F; Herrmann, H J

    2016-01-01

    Through molecular mechanics we find that non-covalent interactions modify the fractality of crumpled damaged graphene. Pristine graphene membranes are damaged by adding random vacancies and carbon-hydrogen bonds. Crumpled membranes exhibit a fractal dimension of $ 2.71 \\pm 0.02$ when all interactions between carbon atoms are considered, and $2.30 \\pm 0.05$ when non-covalent interactions are suppressed. The transition between these two values, obtained by switching on/off the non-covalent interactions of equilibrium configurations, is shown to be reversible and independent on thermalisation. In order to explain this transition, we propose a theoretical model that is compatible with our numerical findings. Finally, we also compare damaged graphene membranes with other crumpled structures, as for instance, polymerised membranes and paper sheets, that share similar scaling properties.

  4. Indirect identification of damage functions from damage records

    CERN Document Server

    Steinhäuser, J Micha; Kropp, Jürgen P

    2015-01-01

    In order to assess future damage caused by natural disasters, it is desirable to estimate the damage caused by single events. So called damage functions provide -- for a natural disaster of certain magnitude -- a specific damage value. However, in general, the functional form of such damage functions is unknown. We study the distributions of recorded flood damages on extended scales and deduce which damage functions lead to such distributions when the floods obey Generalized Extreme Value statistics and follow Generalized Pareto distributions. Based on the finding of broad damage distributions we investigate two possible functional forms to characterize the data. In the case of Gumbel distributed extreme events, (i) a power-law distribution density with an exponent close to 2 (Zipf's law) implies an exponential damage function; (ii) stretched exponential distribution densities imply power-law damage functions. In the case of Weibull (Frechet) distributed extreme events we find correspondingly steeper (less st...

  5. A Hypothesis on Biological Protection from Space Radiation Through the Use of New Therapeutic Gases as Medical Counter Measures

    Science.gov (United States)

    Schoenfeld, Michael P.; Ansari, Rafat R.; Nakao, Atsunori; Wink, David

    2012-01-01

    Radiation exposure to astronauts could be a significant obstacle for long duration manned space exploration because of current uncertainties regarding the extent of biological effects. Furthermore, concepts for protective shielding also pose a technically challenging issue due to the nature of cosmic radiation and current mass and power constraints with modern exploration technology. The concern regarding exposure to cosmic radiation is the biological damage it induces. As damage is associated with increased oxidative stress, it is important and would be enabling to mitigate and/or prevent oxidative stress prior to the development of clinical symptoms and disease. This paper hypothesizes a "systems biology" approach in which a combination of chemical and biological mitigation techniques are used conjunctively. It proposes using new, therapeutic, medical gases as both chemical radioprotectors for radical scavenging and biological signaling molecules for management of the body s response to exposure. From reviewing radiochemistry of water, biological effects of CO, H2, NO, and H2S gas, and mechanisms of radiation biology, it is concluded that this approach may have great therapeutic potential for radiation exposure. Furthermore, it also appears to have similar potential for curtailing the pathogenesis of other diseases in which oxidative stress has been implicated including cardiovascular disease, cancer, chronic inflammatory disease, hypertension, ischemia/reperfusion injury, acute respiratory distress syndrome, Parkinson s and Alzheimer s disease, cataracts, and aging.

  6. Damage localization using experimental modal parameters and topology optimization

    OpenAIRE

    Niemann, Hanno; Morlier, Joseph; Shahdin, Amir; Gourinat, Yves

    2010-01-01

    This work focuses on the developement of a damage detection and localization tool using the Topology Optimization feature of MSC.Nastran. This approach is based on the correlation of a local stiness loss and the change in modal parameters due to damages in structures. The loss in stiness is accounted by the Topology Optimization approach for updating undamaged numerical models towards similar models with embedded damages. Hereby, only a mass penalization and the changes in experimentally obta...

  7. Quantum Biology

    Directory of Open Access Journals (Sweden)

    Alessandro Sergi

    2009-06-01

    Full Text Available A critical assessment of the recent developmentsof molecular biology is presented.The thesis that they do not lead to a conceptualunderstanding of life and biological systems is defended.Maturana and Varela's concept of autopoiesis is briefly sketchedand its logical circularity avoided by postulatingthe existence of underlying living processes,entailing amplification from the microscopic to the macroscopic scale,with increasing complexity in the passage from one scale to the other.Following such a line of thought, the currently accepted model of condensed matter, which is based on electrostatics and short-ranged forces,is criticized. It is suggested that the correct interpretationof quantum dispersion forces (van der Waals, hydrogen bonding, and so onas quantum coherence effects hints at the necessity of includinglong-ranged forces (or mechanisms for them incondensed matter theories of biological processes.Some quantum effects in biology are reviewedand quantum mechanics is acknowledged as conceptually important to biology since withoutit most (if not all of the biological structuresand signalling processes would not even exist. Moreover, it is suggested that long-rangequantum coherent dynamics, including electron polarization,may be invoked to explain signal amplificationprocess in biological systems in general.

  8. Biological response modifiers

    Energy Technology Data Exchange (ETDEWEB)

    Weller, R.E.

    1991-10-01

    Much of what used to be called immunotherapy is now included in the term biological response modifiers. Biological response modifiers (BRMs) are defined as those agents or approaches that modify the relationship between the tumor and host by modifying the host's biological response to tumor cells with resultant therapeutic effects.'' Most of the early work with BRMs centered around observations of spontaneous tumor regression and the association of tumor regression with concurrent bacterial infections. The BRM can modify the host response in the following ways: Increase the host's antitumor responses through augmentation and/or restoration of effector mechanisms or mediators of the host's defense or decrease the deleterious component by the host's reaction; Increase the host's defenses by the administration of natural biologics (or the synthetic derivatives thereof) as effectors or mediators of an antitumor response; Augment the host's response to modified tumor cells or vaccines, which might stimulate a greater response by the host or increase tumor-cell sensitivity to an existing response; Decrease the transformation and/or increase differentiation (maturation) of tumor cells; or Increase the ability of the host to tolerate damage by cytotoxic modalities of cancer treatment.

  9. Electron beam damage in high temperature polymers

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S. (Dayton Univ., OH (USA). Research Inst.); Adams, W.W. (Air Force Materials Lab., Wright-Patterson AFB, OH (USA))

    1990-01-01

    Electron microscopic studies of polymers are limited due to beam damage. Two concerns are the damage mechanism in a particular material, and the maximum dose for a material before damage effects are observed. From the knowledge of the dose required for damage to the polymer structure, optimum parameters for electron microscopy imaging can be determined. In the present study, electron beam damage of polymers has been quantified by monitoring changes in the diffraction intensity as a function of electron dose. The beam damage characteristics of the following polymers were studied: poly(p-phenylene benzobisthiazole) (PBZT); poly(p-phenylene benzobisoxazole) (PBO); poly(benzoxazole) (ABPBO); poly(benzimidazole) (ABPBI); poly(p-phenylene terephthalamide) (PPTA); and poly(aryl ether ether ketone) (PEEK). Previously published literature results on polyethylene (PE), polyoxymethylene (POM), nylon-6, poly(ethylene oxide) (PEO), PBZT, PPTA, PPX, iPS, poly(butylene terephthalate) (PBT), and poly(phenylene sulphide) (PPS) were reviewed. This study demonstrates the strong dependence of the electron beam resistivity of a polymer on its thermal stability/melt temperature. (author).

  10. Assessment of forest damage due to ice storm using image thresholding techniques: A case study of Yunnan Province%基于图像阈值法的森林雪灾损失遥感估测——以云南省为例

    Institute of Scientific and Technical Information of China (English)

    吴健生; 陈莎; 彭建

    2013-01-01

    Ice storms are one of the severe disruptions to forest ecological systems,causing vegetation loss and reduction of the ecological systems' functions.For this reason it is vital to assess the damages to forests after ice storms.Using SPOT Normalized Difference Vegetation Index(NDVI) time serial images of Yunnan Province of China during 2000-2011,forest damage caused by ice storms in 2008 was assessed based on image thresholding techniques of post-storm NDVI time series after Savitzky-Golay filtering by TIMESAT software.The damage threshold was determined by the difference of standard deviation between the years with ice storms and those without,which eventually turned out to be 21%.The range of extracted forest damage is almost consistent with the ice storm extent of Yunnan in the national monthly disaster report,therefore the result is reliable.The destroyed vegetation accounted for 12.09% of the total area of forest.Forest within Diqing County and Nujiang County,in northwest Yunnan,suffered the most losses.On the whole,seven counties took the worst hit by the natural adversity,while thirteen were moderately affected and forty five slightly affected.The most severe damage of forest occurred at the elevation of 3300 m to 4000 m,the slope of 5 to 15 degree,the middle slope position and the east or northeast aspect.Even so,it had little to do with slope position because the most of vegetation is located in the middle slope position.In-situ measurement was not employed here to verify the results because of time and money limits,which compromised the overall accuracy.However,with the acceptable precision,the research method can be used as a real-time forest loss assessment,which is of great significance for taking effective measures to avoid secondary impacts and starting the process of recovery.%雪灾是森林生态系统的严重生态干扰之一,会严重影响林木生长并降低生态系统功能.利用2000-2011年SPOT NDVI长时间序列影像数据,基

  11. The holy grail : predicting localized corrosion damage from first principles

    Energy Technology Data Exchange (ETDEWEB)

    Macdonald, D.D. [Pennsylvania State Univ., University Park, PA (United States). Centre for Electrochemical Science and Technology; Engelhardt, G. [OLI Systems Inc., Morris Plains, NJ (United States)

    2005-07-01

    The safe and economic operation of power plants, refineries and desalination systems can be threatened by localized corrosion in complex industrial systems. The development of effective localized corrosion damage prediction technology is essential for avoiding unscheduled downtime and for developing a strategy to extend the service life of the system. There is great interest in developing algorithms to predict the integrated damage as a function of time and as a function of the operating conditions of the system. This paper outlined the foundations of the deterministic prediction of damage due to localized corrosion. In the deterministic approach, damage development is described in terms of valid, physico-electrochemical mechanisms with the output being constrained by natural laws. The outline included the theoretical bases for predicting a complete cycle of damage development in terms of the nucleation, growth, and death of individual events and the evolution of damage in a series of events occurring in a progressive manner. Damage was expressed in terms of event frequency versus incremental depth. The use of damage function analysis (DFA) was also illustrated with reference to the prediction of pitting damage on aluminum in chloride-containing solution. The accumulation of damage due to stress corrosion cracking (SCC) in type 305 stainless steel components in a water-cooled nuclear power reactor was also examined. 39 refs., 10 figs.

  12. Simulating past droughts and associated building damages in France

    Directory of Open Access Journals (Sweden)

    T. Corti

    2009-09-01

    Full Text Available Droughts can induce important building damages due to shrinking and swelling of soils, leading to costs as large as for floods in some regions. Previous studies have focused on damage data analysis, geological or constructional aspects. Here, a study investigating the climatic aspects of soil subsidence damage is presented for the first time. We develop a simple model to examine if the meteorology has a considerable impact on the interannual variability of damages from soil subsidence in France. We find that the model is capable of reproducing yearly drought-induced building damages for the time period 1989–2002, thus suggesting a strong meteorological influence. Furthermore, our results reveal a doubling of damages in these years compared to 1961–1990, mainly as a consequence of increasing temperatures. This indicates a link to climate change. We also apply the model to the extreme summer of 2003, which caused a further increase in damage by a factor four, according to a preliminary damage estimate. The simulation result for that year shows strong damage underestimation, pointing to additional sources of vulnerability. Damage data suggest a higher sensitivity to soil subsidence of regions first affected by drought in the 2003 summer, possibly due to a lack of preparedness and adaptation. This is of strong concern in the context of climate change, as densely populated regions in Central Europe and North America are expected to become newly affected by drought in the future.

  13. Technical Due Diligence

    DEFF Research Database (Denmark)

    Jensen, Per Anker; Varano, Mattia

    2011-01-01

    Technical Due Diligence (TDD) as an evaluation of the performance of constructed facilities has become an important new field of practice for consultants. Before the financial crisis started in autumn 2008 it represented the fastest growing activity in some consulting companies. TDD is mostly...... carried out for buyers or sellers involved in real estate transactions. It can also be part of mergers including real estate and other assets or part of facilities management outsourcing. This paper is based on a case study and an interview survey of companies involved in TDD consulting in Denmark......, the investigation of current practice also identifies examples of value adding practices, which can give the companies in question competitive advantages by differentiation and/or give input to improvements of the recommended practice guidelines....

  14. Drivers of flood damage on event level

    Science.gov (United States)

    Kreibich, Heidi

    2016-04-01

    Flood risk is dynamic and influenced by many processes related to hazard, exposure and vulnerability. Flood damage increased significantly over the past decades, however, resulting overall economic loss per event is an aggregated indicator and it is difficult to attribute causes to this increasing trend. Much has been learned about damaging processes during floods at the micro-scale, e.g. building level. However, little is known about the main factors determining the amount of flood damage on event level. Thus, we analyse and compare paired flood events, i.e. consecutive, similar damaging floods that occurred in the same area. In analogy to 'Paired catchment studies' - a well-established method in hydrology to understand how changes in land use affect streamflow - we will investigate how and why resulting flood damage in a region differed between the first and second consecutive flood events. One example are the 2002 and 2013 floods in the Elbe and Danube catchments in Germany. The 2002 flood caused the highest economic damage (EUR 11600 million) due to a natural hazard event in Germany. Damage was so high due to extreme flood hazard triggered by extreme precipitation and a high number of resulting dyke breaches. Additionally, exposure hotspots like the city of Dresden at the Elbe river as well as some smaller municipalities at the river Mulde (e.g. Grimma, Eilenburg, Bitterfeld, Dessau) were severely impacted. However, affected parties and authorities learned from the extreme flood in 2002, and many governmental flood risk programs and initiatives were launched. Considerable improvements since 2002 occurred on many levels that deal with flood risk reduction and disaster response, in particular in 1) increased flood prevention by improved spatial planning, 2) an increased number of property-level mitigation measures, 3) more effective early warning and improved coordination of disaster response and 4) a more targeted maintenance of flood defence systems and their

  15. Quantum Biology

    CERN Document Server

    Sergi, Alessandro

    2009-01-01

    A critical assessment of the recent developments of molecular biology is presented. The thesis that they do not lead to a conceptual understanding of life and biological systems is defended. Maturana and Varela's concept of autopoiesis is briefly sketched and its logical circularity avoided by postulating the existence of underlying {\\it living processes}, entailing amplification from the microscopic to the macroscopic scale, with increasing complexity in the passage from one scale to the other. Following such a line of thought, the currently accepted model of condensed matter, which is based on electrostatics and short-ranged forces, is criticized. It is suggested that the correct interpretation of quantum dispersion forces (van der Waals, hydrogen bonding, and so on) as quantum coherence effects hints at the necessity of including long-ranged forces (or mechanisms for them) in condensed matter theories of biological processes. Some quantum effects in biology are reviewed and quantum mechanics is acknowledge...

  16. Biological warfare agents

    Directory of Open Access Journals (Sweden)

    Duraipandian Thavaselvam

    2010-01-01

    Full Text Available The recent bioterrorist attacks using anthrax spores have emphasized the need to detect and decontaminate critical facilities in the shortest possible time. There has been a remarkable progress in the detection, protection and decontamination of biological warfare agents as many instrumentation platforms and detection methodologies are developed and commissioned. Even then the threat of biological warfare agents and their use in bioterrorist attacks still remain a leading cause of global concern. Furthermore in the past decade there have been threats due to the emerging new diseases and also the re-emergence of old diseases and development of antimicrobial resistance and spread to new geographical regions. The preparedness against these agents need complete knowledge about the disease, better research and training facilities, diagnostic facilities and improved public health system. This review on the biological warfare agents will provide information on the biological warfare agents, their mode of transmission and spread and also the detection systems available to detect them. In addition the current information on the availability of commercially available and developing technologies against biological warfare agents has also been discussed. The risk that arise due to the use of these agents in warfare or bioterrorism related scenario can be mitigated with the availability of improved detection technologies.

  17. Micromechanics of diffusion-induced damage evolution in reinforced polymers

    DEFF Research Database (Denmark)

    Abhilash, A.S.; Joshi, Shailendra P.; Mukherjee, Abhijit;

    2011-01-01

    In this work we numerically investigate the nucleation and evolution of micromechanical damage in reinforced glassy polymers under transient hygro-mechanical loading. In particular, we demonstrate the role that fiber distribution plays in the evolution of overall damage due to fiber–matrix interf...

  18. Modeling laser damage to the retina

    Science.gov (United States)

    Clark, Clifton D.

    significantly for wavelengths in the near infrared due to an increase in the absorption coefficient for these long wavelengths. This means that less energy actually reaches the retina, but it also means that more energy is absorbed by the vitreous which can lead to significant temperature rises. The refractive index of water is known to depend on temperature, and the vitreous has very similar optical properties to water, so temperature gradients in the vitreous lead to refractive index gradients that act as a lens. Since the refractive index of water decreases with an increase in temperature, the overall effect is to establish a negative lens that defocuses a beam inside the eye during a laser exposure. This effect is a potential protection mechanism for the retina, as it would limit the time for which a laser can be sharply focused on the retina. Our model agrees well with thermal lensing measurements that have been conducted in water and we have used it to predict the retinal damage threshold as a function of exposure duration for 1318 nm exposures at various beam diameters. The model predicts that the damage threshold remains constant after some exposure time, which depends on the beam diameter. This is due mainly to the fact the retinal temperature rise is limited by the thermal lens and reaches a peak value in a relatively short time (on the order of 10 ms), which limits the amount of time that a laser exposure can cause damage. Finally, in Chapter 6 we describe the first steps we have taken in building a comprehensive short pulse retina damage model. Currently, no model capable of predicting retinal damage outcome based on the exposure parameters at the cornea exists. Models of possible damage mechanisms do exist (the damage mechanism for pulses less than about 1 mus are non-thermal), but these models assume that the exposure parameters are known at the absorption site (the retina). We have constructed a configurable, linear short pulse propagation model, that is capable

  19. Loss and damage

    Science.gov (United States)

    Huq, Saleemul; Roberts, Erin; Fenton, Adrian

    2013-11-01

    Loss and damage is a relative newcomer to the climate change agenda. It has the potential to reinvigorate existing mitigation and adaptation efforts, but this will ultimately require leadership from developed countries and enhanced understanding of several key issues, such as limits to adaptation.

  20. Impact damage assessment by using peridynamic theory

    Science.gov (United States)

    Oterkus, Erkan; Guven, Ibrahim; Madenci, Erdogan

    2012-12-01

    This study presents an application of peridynamic theory for predicting residual strength of impact damaged building components by considering a reinforced panel subjected to multiple load paths. The validity of the approach is established first by simulating a controlled experiment resulting in mixed-mode fracture of concrete. The agreement between the PD prediction and the experimentally observed behavior is remarkable especially considering the simple material model used for the concrete. Subsequently, the PD simulation concerns damage assessment and residual strength of a reinforced panel under compression after impact due to a rigid penetrator.

  1. Drivers of flood damage on event level

    DEFF Research Database (Denmark)

    Kreibich, H.; Aerts, J. C. J. H.; Apel, H.;

    2016-01-01

    that occurred in the same area. In analogy to ’Paired catchment studies’ - a well-established method in hydrology to understand how changes in land use affect streamflow – we will investigate how and why resulting flood damage in a region differed between the first and second consecutive flood events. One......-level mitigation measures, 3) more effective early warning and improved coordination of disaster response and 4) a more targeted maintenance of flood defence systems and their deliberate relocation. Thus, despite higher hydrological severity damage due to the 2013 flood was significantly lower than in 2002. In our...

  2. Risk of nuclear damage

    International Nuclear Information System (INIS)

    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

  3. Electronic damage in S atoms in a native protein crystal induced by an intense X-ray free-electron laser pulse

    Directory of Open Access Journals (Sweden)

    L. Galli

    2015-07-01

    Full Text Available Current hard X-ray free-electron laser (XFEL sources can deliver doses to biological macromolecules well exceeding 1 GGy, in timescales of a few tens of femtoseconds. During the pulse, photoionization can reach the point of saturation in which certain atomic species in the sample lose most of their electrons. This electronic radiation damage causes the atomic scattering factors to change, affecting, in particular, the heavy atoms, due to their higher photoabsorption cross sections. Here, it is shown that experimental serial femtosecond crystallography data collected with an extremely bright XFEL source exhibit a reduction of the effective scattering power of the sulfur atoms in a native protein. Quantitative methods are developed to retrieve information on the effective ionization of the damaged atomic species from experimental data, and the implications of utilizing new phasing methods which can take advantage of this localized radiation damage are discussed.

  4. Electronic damage in S atoms in a native protein crystal induced by an intense X-ray free-electron laser pulse.

    Science.gov (United States)

    Galli, L; Son, S-K; Klinge, M; Bajt, S; Barty, A; Bean, R; Betzel, C; Beyerlein, K R; Caleman, C; Doak, R B; Duszenko, M; Fleckenstein, H; Gati, C; Hunt, B; Kirian, R A; Liang, M; Nanao, M H; Nass, K; Oberthür, D; Redecke, L; Shoeman, R; Stellato, F; Yoon, C H; White, T A; Yefanov, O; Spence, J; Chapman, H N

    2015-07-01

    Current hard X-ray free-electron laser (XFEL) sources can deliver doses to biological macromolecules well exceeding 1 GGy, in timescales of a few tens of femtoseconds. During the pulse, photoionization can reach the point of saturation in which certain atomic species in the sample lose most of their electrons. This electronic radiation damage causes the atomic scattering factors to change, affecting, in particular, the heavy atoms, due to their higher photoabsorption cross sections. Here, it is shown that experimental serial femtosecond crystallography data collected with an extremely bright XFEL source exhibit a reduction of the effective scattering power of the sulfur atoms in a native protein. Quantitative methods are developed to retrieve information on the effective ionization of the damaged atomic species from experimental data, and the implications of utilizing new phasing methods which can take advantage of this localized radiation damage are discussed. PMID:26798803

  5. DNA damage response in adult stem cells.

    Science.gov (United States)

    Insinga, Alessandra; Cicalese, Angelo; Pelicci, Pier Giuseppe

    2014-04-01

    This review discusses the processes of DNA-damage-response and DNA-damage repair in stem and progenitor cells of several tissues. The long life-span of stem cells suggests that they may respond differently to DNA damage than their downstream progeny and, indeed, studies have begun to elucidate the unique stem cell response mechanisms to DNA damage. Because the DNA damage responses in stem cells and progenitor cells are distinctly different, stem and progenitor cells should be considered as two different entities from this point of view. Hematopoietic and mammary stem cells display a unique DNA-damage response, which involves active inhibition of apoptosis, entry into the cell-cycle, symmetric division, partial DNA repair and maintenance of self-renewal. Each of these biological events depends on the up-regulation of the cell-cycle inhibitor p21. Moreover, inhibition of apoptosis and symmetric stem cell division are the consequence of the down-regulation of the tumor suppressor p53, as a direct result of p21 up-regulation. A deeper understanding of these processes is required before these findings can be translated into human anti-aging and anti-cancer therapies. One needs to clarify and dissect the pathways that control p21 regulation in normal and cancer stem cells and define (a) how p21 blocks p53 functions in stem cells and (b) how p21 promotes DNA repair in stem cells. Is this effect dependent on p21s ability to inhibit p53? Such molecular knowledge may pave the way to methods for maintaining short-term tissue reconstitution while retaining long-term cellular and genomic integrity.

  6. The expected radiation damage of CSNS target

    Science.gov (United States)

    Yin, W.; Yu, Q. Z.; Lu, Y. L.; Wang, S. L.; Tong, J. F.; Liang, T. J.

    2012-12-01

    The radiation damage to the tungsten target and its SS316 vessel for Chinese Spallation Neutron Source (CSNS) has been estimated with a Monte-Carlo simulation code MCNPX2.5.0. We compare the effects on the radiation damage due to two different proton beam profiles: a uniform distribution and a Gaussian distribution. We also discuss the dependence of the radiation damage estimation on different physics models. The results show the peak displacement productions in vessel and the fourth target plate are 2.5 and 5.5 dpa/y, respectively, under a Gaussian proton beam. The peak helium productions in the vessel and the fourth target are 305 and 353 appm/y, respectively, under the same proton beam. Based on these results and the allowable dpa values we have estimated the lifetime of the tungsten target and its vessel.

  7. The expected radiation damage of CSNS target

    Energy Technology Data Exchange (ETDEWEB)

    Yin, W., E-mail: wenyin@aphy.iphy.ac.cn [Engineering Center of CSNS Target Station and Instruments, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Yu, Q.Z. [Engineering Center of CSNS Target Station and Instruments, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Lu, Y.L.; Wang, S.L.; Tong, J.F. [Experimental System of CSNS, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Liang, T.J. [Engineering Center of CSNS Target Station and Instruments, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2012-12-15

    The radiation damage to the tungsten target and its SS316 vessel for Chinese Spallation Neutron Source (CSNS) has been estimated with a Monte-Carlo simulation code MCNPX2.5.0. We compare the effects on the radiation damage due to two different proton beam profiles: a uniform distribution and a Gaussian distribution. We also discuss the dependence of the radiation damage estimation on different physics models. The results show the peak displacement productions in vessel and the fourth target plate are 2.5 and 5.5 dpa/y, respectively, under a Gaussian proton beam. The peak helium productions in the vessel and the fourth target are 305 and 353 appm/y, respectively, under the same proton beam. Based on these results and the allowable dpa values we have estimated the lifetime of the tungsten target and its vessel.

  8. Increased molecular damage and heterogeneity as the basis of aging.

    Science.gov (United States)

    Rattan, Suresh I S

    2008-03-01

    Aging at the molecular level is characterized by the progressive accumulation of molecular damage. The sources of damage act randomly through environmental and metabolically generated free radicals, through spontaneous errors in biochemical reactions, and through nutritional components. However, damage to a macromolecule may depend on its structure, localization and interactions with other macromolecules. Damage to the maintenance and repair pathways comprising homeodynamic machinery leads to age-related failure of homeodynamics, increased molecular heterogeneity, altered cellular functioning, reduced stress tolerance, diseases and ultimate death. Novel approaches for testing and developing effective means of intervention, prevention and modulation of aging involve means to minimize the occurrence and accumulation of molecular damage. Mild stress-induced hormesis by physical, biological and nutritional methods, including hormetins, represents a promising strategy for achieving healthy aging and for preventing age-related diseases.

  9. Endothelial perturbations and therapeutic strategies in normal tissue radiation damage

    International Nuclear Information System (INIS)

    Most cancer patients are treated with radiotherapy, but the treatment can also damage the surrounding normal tissue. Radiotherapy side-effects diminish patients’ quality of life, yet effective biological interventions for normal tissue damage are lacking. Protecting microvascular endothelial cells from the effects of irradiation is emerging as a targeted damage-reduction strategy. We illustrate the concept of the microvasculature as a mediator of overall normal tissue radiation toxicity through cell death, vascular inflammation (hemodynamic and molecular changes) and a change in functional capacity. Endothelial cell targeted therapies that protect against such endothelial cell perturbations and the development of acute normal tissue damage are mostly under preclinical development. Since acute radiation toxicity is a common clinical problem in cutaneous, gastrointestinal and mucosal tissues, we also focus on damage in these tissues

  10. Evaluation of the friction coefficient, the radial stress, and the damage work during needle insertions into agarose gels.

    Science.gov (United States)

    Urrea, Fabián A; Casanova, Fernando; Orozco, Gustavo A; García, José J

    2016-03-01

    Agarose hydrogels have been extensively used as a phantom material to mimic the mechanical behavior of soft biological tissues, e.g. in studies aimed to analyze needle insertions into the organs producing tissue damage. To better predict the radial stress and damage during needle insertions, this study was aimed to determine the friction coefficient between the material of commercial catheters and hydrogels. The friction coefficient, the tissue damage and the radial stress were evaluated at 0.2, 1.8, and 10mm/s velocities for 28, 30, and 32 gauge needles of outer diameters equal to 0.36, 0.31, and 0.23mm, respectively. Force measurements during needle insertions and retractions on agarose gel samples were used to analyze damage and radial stress. The static friction coefficient (0.295±0.056) was significantly higher than the dynamic (0.255±0.086). The static and dynamic friction coefficients were significantly smaller for the 0.2mm/s velocity compared to those for the other two velocities, and there was no significant difference between the friction coefficients for 1.8 and 10mm/s. Radial stress averages were 131.2±54.1, 248.3±64.2, and 804.9±164.3Pa for the insertion velocity of 0.2, 1.8, and 10mm/s, respectively. The radial stress presented a tendency to increase at higher insertion velocities and needle size, which is consistent with other studies. However, the damage work did not show to be a good predictor of tissue damage, which appears to be due to simplifications in the analytical model. Differently to other approaches, the method proposed here based on radial stress may be extended in future studies to quantity tissue damage in vivo along the entire needle track. PMID:26700572

  11. Radiation damage tolerant nanomaterials

    Directory of Open Access Journals (Sweden)

    I.J. Beyerlein

    2013-11-01

    Full Text Available Designing a material from the atomic level to achieve a tailored response in extreme conditions is a grand challenge in materials research. Nanostructured metals and composites provide a path to this goal because they contain interfaces that attract, absorb and annihilate point and line defects. These interfaces recover and control defects produced in materials subjected to extremes of displacement damage, impurity implantation, stress and temperature. Controlling radiation-induced-defects via interfaces is shown to be the key factor in reducing the damage and imparting stability in certain nanomaterials under conditions where bulk materials exhibit void swelling and/or embrittlement. We review the recovery of radiation-induced point defects at free surfaces and grain boundaries and stabilization of helium bubbles at interphase boundaries and present an approach for processing bulk nanocomposites containing interfaces that are stable under irradiation.

  12. Hypertension and cerebrovascular damage.

    Science.gov (United States)

    Veglio, Franco; Paglieri, Cristina; Rabbia, Franco; Bisbocci, Daniela; Bergui, Mauro; Cerrato, Paolo

    2009-08-01

    Hypertension is the most important modifiable factor for cerebrovascular disease. Stroke and dementia are growing health problems that have considerable social and economical consequences. Hypertension causes brain lesions by several mechanisms predisposing to lacunar infarctions, leucoaraiosis, and white matter changes as well as to intracerebral haemorrhages. These parenchymal damages determine evident or silent neurological alterations that often precede the onset of cognitive decline. It is important to recognize cerebrovascular disease and, above all, to correlate typical lesions to hypertension. Antihypertensive therapy has shown clinical benefits in primary and secondary prevention of stroke. These drugs represent important instruments against cerebrovascular disease but their effects on cognition are still matter of debate. Cerebral parenchymal and functional damages have to be considered together to make medical intervention more incisive. PMID:19100549

  13. Radiation damage effects

    International Nuclear Information System (INIS)

    The summarized data suggest that both glass and crystalline waste forms may sustain substantial doses of α-decay damage and still retain their durability. Radiation effects in glasses are less pronounced and less complicated than that in single or poly-phase ceramics; thus, the latter category requires careful research and consideration. Perhaps the most important conclusion is that short-term actinide doping experiments in crystalline phases provide a realistic simulation of long-term effects based on the comparison of observed radiation effects in Pu-doped zircon and naturally damaged zircon (there is a 107 difference in dose rate). Deviations from the similarity in effect (e.g., saturation dose) may be attributed to low-temperature, long-term annealing effects

  14. Compensation for nuclear damage

    International Nuclear Information System (INIS)

    To secure fair and efficient compensation for damage likely to be caused by the utilisation of nuclear energy, a special civil liability regime was set up by several international conventions. Three of these conventions are in force and Spain is a Contracting Party to all three. The principles established in the first instance at European level by the Paris Convention (absolute and exclusive liability of the nuclear operator, limitation of such liability, compulsory insurance...) are intended to guarantee that possible victims of a nuclear incident will obtain compensation for damage suffered. The Brussels Convention Supplementary to the Paris Convention provides for official funds to compensate victims through intervention by the Contracting Parties. Each Contracting Party should implement these Conventions at national level by appropriate legislation, which is what Spain did with its Act on Nuclear Energy of 29th April 1964, as supplemented in 1967 by the Regulations on Cover for Nuclear Hazards. (N.E.A.)

  15. Biological Oceanography

    Science.gov (United States)

    Abbott, M. R.

    1984-01-01

    Within the framework of global biogeochemical cycles and ocean productivity, there are two areas that will be of particular interest to biological oceanography in the 1990s. The first is the mapping in space time of the biomass and productivity of phytoplankton in the world ocean. The second area is the coupling of biological and physical processes as it affects the distribution and growth rate of phytoplankton biomass. Certainly other areas will be of interest to biological oceanographers, but these two areas are amenable to observations from satellites. Temporal and spatial variability is a regular feature of marine ecosystems. The temporal and spatial variability of phytoplankton biomass and productivity which is ubiquitous at all time and space scales in the ocean must be characterized. Remote sensing from satellites addresses these problems with global observations of mesocale (2 to 20 days, 10 to 200 km) features over a long period of time.

  16. Restoring Damaged Aquatic Ecosystems

    OpenAIRE

    Cairns, John

    2006-01-01

    Aquatic ecosystems must play a major role to ensure that water, which is both essential and scarce, is always available for both present and future generations. This has become even more urgent in light of the ongoing increase in total world population and predicted changes in the world climate. Since aquatic ecosystems have been damaged at a rate far in excess of both natural restoration and anthropogenic restoration, it is essential that both restorative processes be accelerated. However, e...

  17. Tornado damage risk assessment

    International Nuclear Information System (INIS)

    Several proposed models were evaluated for predicting tornado wind speed probabilities at nuclear plant sites as part of a program to develop statistical data on tornadoes needed for probability-based load combination analysis. A unified model was developed which synthesized the desired aspects of tornado occurrence and damage potential. The sensitivity of wind speed probability estimates to various tornado modeling assumptions are examined, and the probability distributions of tornado wind speed that are needed for load combination studies are presented

  18. Quality control of chemically damaged RNA.

    Science.gov (United States)

    Simms, Carrie L; Zaher, Hani S

    2016-10-01

    The "central dogma" of molecular biology describes how information contained in DNA is transformed into RNA and finally into proteins. In order for proteins to maintain their functionality in both the parent cell and subsequent generations, it is essential that the information encoded in DNA and RNA remains unaltered. DNA and RNA are constantly exposed to damaging agents, which can modify nucleic acids and change the information they encode. While much is known about how cells respond to damaged DNA, the importance of protecting RNA has only become appreciated over the past decade. Modification of the nucleobase through oxidation and alkylation has long been known to affect its base-pairing properties during DNA replication. Similarly, recent studies have begun to highlight some of the unwanted consequences of chemical damage on mRNA decoding during translation. Oxidation and alkylation of mRNA appear to have drastic effects on the speed and fidelity of protein synthesis. As some mRNAs can persist for days in certain tissues, it is not surprising that it has recently emerged that mRNA-surveillance and RNA-repair pathways have evolved to clear or correct damaged mRNA. PMID:27155660

  19. Radiation damage in WC studied with MD simulations

    Energy Technology Data Exchange (ETDEWEB)

    Traeskelin, P. [Accelerator Laboratory, University of Helsinki, P.O. Box 43, FIN-00014 (Finland); Bjoerkas, C. [Accelerator Laboratory, University of Helsinki, P.O. Box 43, FIN-00014 (Finland); Juslin, N. [Accelerator Laboratory, University of Helsinki, P.O. Box 43, FIN-00014 (Finland)]. E-mail: niklas.juslin@helsinki.fi; Voertler, K. [Accelerator Laboratory, University of Helsinki, P.O. Box 43, FIN-00014 (Finland); Nordlund, K. [Accelerator Laboratory, University of Helsinki, P.O. Box 43, FIN-00014 (Finland)

    2007-04-15

    Studying radiation damage in tungsten carbide (WC) is of importance due to its applications in fusion reactors. We have used molecular dynamics to study both deuterium induced sputtering and modification of WC surfaces and collision cascades in bulk WC. For collision cascades in bulk WC we note a massive recombination and major elemental asymmetry for the damage. Studying the erosion of WC surfaces, we find that C can erode through swift chemical sputtering, while W does not sputter more easily than from pure W. The amorphization of the surface and the D-content due to the D bombardment is important for the damage production and sputtering process.

  20. Radiation damage of the ILC positron source target

    Energy Technology Data Exchange (ETDEWEB)

    Ushakov, A.; Riemann, S.

    2007-11-15

    The radiation damage of the positron source target for the International Linear Collider (ILC) has been studied. The displacement damage in target material due to multi-MeV photons has been calculated by combining FLUKA simulations for secondary particle production, SPECTER data for neutron displacement cross-sections and the Lindhard model for estimations of displacement damage by ions. The radiation damage of a stationary Ti6Al4V target in units of displacements per atom (dpa) has been estimated for photons from an undulator with strength 0.92 and period 1.15 cm. The calculated damage is 7 dpa. Approximately 12.5% of displacement damage result from neutrons. (orig.)

  1. Biology Notes.

    Science.gov (United States)

    School Science Review, 1981

    1981-01-01

    Outlines a variety of laboratory procedures, techniques, and materials including construction of a survey frame for field biology, a simple tidal system, isolation and applications of plant protoplasts, tropisms, teaching lung structure, and a key to statistical methods for biologists. (DS)

  2. (Biological dosimetry)

    Energy Technology Data Exchange (ETDEWEB)

    Preston, R.J.

    1990-12-17

    The traveler attended the 1st International Conference on Biological Dosimetry in Madrid, Spain. This conference was organized to provide information to a general audience of biologists, physicists, radiotherapists, industrial hygiene personnel and individuals from related fields on the current ability of cytogenetic analysis to provide estimates of radiation dose in cases of occupational or environmental exposure. There is a growing interest in Spain in biological dosimetry because of the increased use of radiation sources for medical and occupational uses, and with this the anticipated and actual increase in numbers of overexposure. The traveler delivered the introductory lecture on Biological Dosimetry: Mechanistic Concepts'' that was intended to provide a framework by which the more applied lectures could be interpreted in a mechanistic way. A second component of the trip was to provide advice with regard to several recent cases of overexposure that had been or were being assessed by the Radiopathology and Radiotherapy Department of the Hospital General Gregorio Maranon'' in Madrid. The traveler had provided information on several of these, and had analyzed cells from some exposed or purportedly exposed individuals. The members of the biological dosimetry group were referred to individuals at REACTS at Oak Ridge Associated Universities for advice on follow-up treatment.

  3. Biology Notes.

    Science.gov (United States)

    School Science Review, 1984

    1984-01-01

    Presents information on the teaching of nutrition (including new information relating to many current O-level syllabi) and part 16 of a reading list for A- and S-level biology. Also includes a note on using earthworms as a source of material for teaching meiosis. (JN)

  4. Attentional bias towards and away from fearful faces is modulated by developmental amygdala damage.

    Science.gov (United States)

    Pishnamazi, Morteza; Tafakhori, Abbas; Loloee, Sogol; Modabbernia, Amirhossein; Aghamollaii, Vajiheh; Bahrami, Bahador; Winston, Joel S

    2016-08-01

    The amygdala is believed to play a major role in orienting attention towards threat-related stimuli. However, behavioral studies on amygdala-damaged patients have given inconsistent results-variously reporting decreased, persisted, and increased attention towards threat. Here we aimed to characterize the impact of developmental amygdala damage on emotion perception and the nature and time-course of spatial attentional bias towards fearful faces. We investigated SF, a 14-year-old with selective bilateral amygdala damage due to Urbach-Wiethe disease (UWD), and ten healthy controls. Participants completed a fear sensitivity questionnaire, facial expression classification task, and dot-probe task with fearful or neutral faces for spatial cueing. Three cue durations were used to assess the time-course of attentional bias. SF expressed significantly lower fear sensitivity, and showed a selective impairment in classifying fearful facial expressions. Despite this impairment in fear recognition, very brief (100 msec) fearful cues could orient SF's spatial attention. In healthy controls, the attentional bias emerged later and persisted longer. SF's attentional bias was due solely to facilitated engagement to fear, while controls showed the typical phenomenon of difficulty in disengaging from fear. Our study is the first to demonstrate the separable effects of amygdala damage on engagement and disengagement of spatial attention. The findings indicate that multiple mechanisms contribute in biasing attention towards fear, which vary in their timing and dependence on amygdala integrity. It seems that the amygdala is not essential for rapid attention to emotion, but probably has a role in assessment of biological relevance. PMID:27173975

  5. Cavitation damage prediction for the JSNS mercury target vessel

    Science.gov (United States)

    Naoe, Takashi; Kogawa, Hiroyuki; Wakui, Takashi; Haga, Katsuhiro; Teshigawara, Makoto; Kinoshita, Hidetaka; Takada, Hiroshi; Futakawa, Masatoshi

    2016-01-01

    The liquid mercury target system for the Japan Spallation Neutron Source (JSNS) at the Materials and Life science experimental Facility (MLF) in the Japan Proton Accelerator Research Complex (J-PARC) is designed to produce pulsed neutrons. The mercury target vessel in this system, which is made of type 316L stainless steel, is damaged by pressure wave-induced cavitation due to proton beam bombardment. Currently, cavitation damage is considered to be the dominant factor influencing the service life of the target vessel rather than radiation damage. In this study, cavitation damage to the interior surface of the target vessel was predicted on the basis of accumulated damage data from off-beam and on-beam experiments. The predicted damage was compared with the damage observed in a used target vessel. Furthermore, the effect of injecting gas microbubbles on cavitation damage was predicted through the measurement of the acoustic vibration of the target vessel. It was shown that the predicted depth of cavitation damage is reasonably coincident with the observed results. Moreover, it was confirmed that the injection of gas microbubbles had an effect on cavitation damage.

  6. Microfluidic Technologies for Synthetic Biology

    Directory of Open Access Journals (Sweden)

    Sung Kuk Lee

    2011-06-01

    Full Text Available Microfluidic technologies have shown powerful abilities for reducing cost, time, and labor, and at the same time, for increasing accuracy, throughput, and performance in the analysis of biological and biochemical samples compared with the conventional, macroscale instruments. Synthetic biology is an emerging field of biology and has drawn much attraction due to its potential to create novel, functional biological parts and systems for special purposes. Since it is believed that the development of synthetic biology can be accelerated through the use of microfluidic technology, in this review work we focus our discussion on the latest microfluidic technologies that can provide unprecedented means in synthetic biology for dynamic profiling of gene expression/regulation with high resolution, highly sensitive on-chip and off-chip detection of metabolites, and whole-cell analysis.

  7. Biology of Infantile Hemangioma

    OpenAIRE

    Itinteang, Tinte; Withers, Aaron H. J.; Davis, Paul F.; Tan, Swee T.

    2014-01-01

    Infantile hemangioma (IH), the most common tumor of infancy, is characterized by an initial proliferation during infancy followed by spontaneous involution over the next 5–10 years, often leaving a fibro-fatty residuum. IH is traditionally considered a tumor of the microvasculature. However, recent data show the critical role of stem cells in the biology of IH with emerging evidence suggesting an embryonic developmental anomaly due to aberrant proliferation and differentiation of a hemogenic ...

  8. Investigating DNA Damage

    Science.gov (United States)

    Bush, Stephen P.; Hart, Peter E.; Russell, Eric M.

    2006-01-01

    Advances in the field of molecular biology, powered by a technological revolution, have increased dramatically over the past decades. Notable developments such as the cloning of adult sheep, the sequencing of the human genome, and the production of genetically modified organisms capture the attention of biologists, their students, and the general…

  9. Damage Modelling For Composite Structures

    OpenAIRE

    Lee, Hao

    2015-01-01

    Modelling damage in composite materials has played an important role in designing composite structures. Although numerical models for the progressive damage in laminated composites (e.g. transverse cracking, delamination and fibre breakage) have been developed in the literature, there is still a need for further improvement. This thesis aimed at developing damage models suitable for predicting intra-laminar and inter-laminar damage behaviour in fibre-reinforced composite materials. Several ap...

  10. Radiation damage in semiconductor detectors

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Cantilever steel post damaged by wind

    Directory of Open Access Journals (Sweden)

    Wei Sha

    2014-10-01

    Full Text Available An analysis for the cause of fracture failure of a cantilever steel sign post damaged by wind has been carried out. An unusual cause of failure has been identified, which is the subject of this paper. Microscopy and microanalysis of the fracture surface showed that the failure was due to pre-existing cracks, from the fabrication of the post. This conclusion was reached after detecting and analysing a galvanised layer on the fracture surfaces.

  12. Stochastic Effects in Computational Biology of Space Radiation Cancer Risk

    Science.gov (United States)

    Cucinotta, Francis A.; Pluth, Janis; Harper, Jane; O'Neill, Peter

    2007-01-01

    Estimating risk from space radiation poses important questions on the radiobiology of protons and heavy ions. We are considering systems biology models to study radiation induced repair foci (RIRF) at low doses, in which less than one-track on average transverses the cell, and the subsequent DNA damage processing and signal transduction events. Computational approaches for describing protein regulatory networks coupled to DNA and oxidative damage sites include systems of differential equations, stochastic equations, and Monte-Carlo simulations. We review recent developments in the mathematical description of protein regulatory networks and possible approaches to radiation effects simulation. These include robustness, which states that regulatory networks maintain their functions against external and internal perturbations due to compensating properties of redundancy and molecular feedback controls, and modularity, which leads to general theorems for considering molecules that interact through a regulatory mechanism without exchange of matter leading to a block diagonal reduction of the connecting pathways. Identifying rate-limiting steps, robustness, and modularity in pathways perturbed by radiation damage are shown to be valid techniques for reducing large molecular systems to realistic computer simulations. Other techniques studied are the use of steady-state analysis, and the introduction of composite molecules or rate-constants to represent small collections of reactants. Applications of these techniques to describe spatial and temporal distributions of RIRF and cell populations following low dose irradiation are described.

  13. Tokamak ARC damage

    International Nuclear Information System (INIS)

    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

  14. Contextualizing aquired brain damage

    DEFF Research Database (Denmark)

    Nielsen, Charlotte Marie Bisgaard

    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....

  15. 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...

  16. Radiation damage in graphite

    CERN Document Server

    Simmons, John Harry Walrond

    1965-01-01

    Nuclear Energy, Volume 102: Radiation Damage in Graphite provides a general account of the effects of irradiation on graphite. This book presents valuable work on the structure of the defects produced in graphite crystals by irradiation. Organized into eight chapters, this volume begins with an overview of the description of the methods of manufacturing graphite and of its physical properties. This text then presents details of the method of setting up a scale of irradiation dose. Other chapters consider the effect of irradiation at a given temperature on a physical property of graphite. This

  17. Analysis of heavy ion induced DNA damage site using high resolution immunofluorescence microscopy imaging

    International Nuclear Information System (INIS)

    Heavy ion therapy is a promising cancer therapy for patients having tumors that cannot be surgically removed or chemotherapeutically treated. Carbon therapy shows less side-effect such as skin inflammation by specifically targeting tumors due to the Bragg peak. Although the clinical benefit is evident, molecular mechanisms underlying heavy ion induced DNA damage response and the repair are not fully understood. Ionizing radiation causes a DNA double strand break, which is one of the toxic DNA damages, leading to cell death if unrepaired. An advanced molecular biology technique enables the visualization of DSB site in individual cell by using immuno-fluorescence microscopy. DNA damage response protein, H2AX, is phosphorylated at DSB site, and it forms discrete focus. Since γH2AX focus represent a DSB site following X-irradiation, this focus assay is utilized as a sensitive technique to detect DSB. Furthermore, advanced microscope technologies enable us to visualize high resolution image by deconvolution which is a computationally intensive image processing technique that is being increasingly utilized for improving the contrast and resolution of digital images captured by the microscope. In this review, we describe our novel technique for DSB repair analysis using high resolution microscope images, and further we discuss an application possibilities of this useful technique for DNA repair research. (author)

  18. Biological monitors for low levels of ionising radiation

    International Nuclear Information System (INIS)

    The biological effects of high doses of ionising radiation are well understood and the methods of measurement of these doses well established. However the effects due to extremely low doses remain by and large uncertain. This is because of the fact that at such low doses no gross symptoms are seen. In fact, at these levels the occurrence of double strand breaks leading to the formation of chromosomal aberrations like dicentrics is rare and chances of mutation due to base damage are negligible. Hence neither chromosomal aberration studies nor mutational assays are useful for detecting doses of the order of a few milligray. Results of exhaustive work done by various laboratories indicate that below 20 mGy the chromosomal aberration technique based on scoring of dicentrics cannot distinguish between a linear or a threshold model. However indirect methods like unscheduled DNA synthesis (UDS) and sister chromatid exchanges (SCEs) appear to be promising for the detection of radiation exposures due to low levels of radiation. This report reviews the available literature on the biological effects of low levels of ionising radiation and highlights the merits and demerits of the various methods employed in the measurement of UDS and SCE. The phenomenon of radio-adaptive response (RAR) and its relation to DNA repair is also discussed. (author)

  19. Subsoil Compaction as a Climate Damage Indicator

    Directory of Open Access Journals (Sweden)

    Márta Birkás

    2009-06-01

    Soil compaction has become a soil management problem during the last decade as a result of the occurrence of periods of water-logging as well as droughts. This study contains an evaluation of factors relating to subsoil compaction, as indicator of climate effects on arable fields. This paper is based on soil condition monitoring and measuring that was started 32 years ago and on short and long-term experiments modeling and checking the extension of compaction in the soil. The survey comprised 1526 monitoring places and 38 experimental plots. The following five points were chosen for monitoring: 1 root zone state (to a depth of 0-60 cm; 2 occurrence of compacted layer (indicating likelihood of risk; 3 extension of the compacted layer (indicating the degree of damage; 4 long term effects of tillage (soil state deterioration or improvement, and 5 tillage-induced water-logging and drought damage impacts on yield loss. The main objectives of the experiments were: 1 occurrence and the extent of tillage-pan damage in soils of different susceptibility to compaction; 2 consequences on water management in each of the years covered by the experiments; 3 soil quality consequences, and 4 alleviation of pan-compaction by mechanical and biological methods. Long-term field monitoring and experimental work have both convincingly proven a correlation between subsoil compaction and the degree of climatic damage. In view of the findings, trends in soil tillage can be grouped into the following two categories: climate damage mitigating and climate-stress increasing ones. The formation and location of compacted layers provided information concerning the depth, the method and the type of tillage applied, along with the expected risk for crop production under extreme climate conditions.

  20. Mesoscopic biology

    Indian Academy of Sciences (India)

    G V Shivashankar

    2002-02-01

    In this paper we present a qualitative outlook of mesoscopic biology where the typical length scale is of the order of nanometers and the energy scales comparable to thermal energy. Novel biomolecular machines, governed by coded information at the level of DNA and proteins, operate at these length scales in biological systems. In recent years advances in technology have led to the study of some of the design principles of these machines; in particular at the level of an individual molecule. For example, the forces that operate in molecular interactions, the stochasticity involved in these interactions and their spatio-temporal dynamics are beginning to be explored. Understanding such design principles is opening new possibilities in mesoscopic physics with potential applications.

  1. Crusts: biological

    Science.gov (United States)

    Belnap, Jayne; Elias, Scott A.

    2013-01-01

    Biological soil crusts, a community of cyanobacteria, lichens, mosses, and fungi, are an essential part of dryland ecosystems. They are critical in the stabilization of soils, protecting them from wind and water erosion. Similarly, these soil surface communities also stabilized soils on early Earth, allowing vascular plants to establish. They contribute nitrogen and carbon to otherwise relatively infertile dryland soils, and have a strong influence on hydrologic cycles. Their presence can also influence vascular plant establishment and nutrition.

  2. Biological programming

    OpenAIRE

    Ramsden, Jeremy J.; Bándi, Gergely

    2010-01-01

    Biology offers a tremendous set of concepts that are potentially very powerfully usable for the software engineer, but they have been barely exploited hitherto. In this position paper we propose a fresh attempt to create the building blocks of a programming technology that could be as successful as life. A key guiding principle is to develop and make use of unambiguous definitions of the essential features of life.

  3. Marine biology

    International Nuclear Information System (INIS)

    This book discusses both taxonomic and ecological topics on marine biology. Full coverage of marine organisms of all five kingdoms is provided, along with interesting and thorough discussion of all major marine habitats. Organization into six major parts allows flexibility. It also provides insight into important topics such as disposal of nuclear waste at sea, the idea that life began on the ocean floor, and how whales, krill, and people interact. A full-color photo chapter reviews questions, and exercises. The contents are: an overview marine biology: fundamental concepts/investigating life in the ocean; the physical ocean, the ocean floor, the nature of water, the nature and motion of ocean water; general ecology, conditions for life in the sea, biological productivity and energy transfer; marine organisms; monera, protista, mycota and metaphyta; the smaller marine animals, the large animals marine habitats, the intertidal zone/benthos of the continental shelf, the photic zone, the deep ocean, the ocean under stress, marine pollution, appendix a: the metric system and conversion factors/ appendix b: prefixes and suffixes/ appendix c: taxonomic classification of common marine organisms, and glossary, and index

  4. Marine biology

    Energy Technology Data Exchange (ETDEWEB)

    Thurman, H.V.; Webber, H.H.

    1984-01-01

    This book discusses both taxonomic and ecological topics on marine biology. Full coverage of marine organisms of all five kingdoms is provided, along with interesting and thorough discussion of all major marine habitats. Organization into six major parts allows flexibility. It also provides insight into important topics such as disposal of nuclear waste at sea, the idea that life began on the ocean floor, and how whales, krill, and people interact. A full-color photo chapter reviews questions, and exercises. The contents are: an overview marine biology: fundamental concepts/investigating life in the ocean; the physical ocean, the ocean floor, the nature of water, the nature and motion of ocean water; general ecology, conditions for life in the sea, biological productivity and energy transfer; marine organisms; monera, protista, mycota and metaphyta; the smaller marine animals, the large animals marine habitats, the intertidal zone/benthos of the continental shelf, the photic zone, the deep ocean, the ocean under stress, marine pollution, appendix a: the metric system and conversion factors/ appendix b: prefixes and suffixes/ appendix c: taxonomic classification of common marine organisms, and glossary, and index.

  5. Excavation damaged zone

    Energy Technology Data Exchange (ETDEWEB)

    Popp, T.; Salzer, K.; Minkley, W. [Institut fur Gebirgsmechanik GmbH, Leipzig (Germany); Gibert, D.; Nicollin, F.; Kergosien, B. [Rennes-1 Univ., GdR FORPRO (CNRS/ANDRA GdR 788) and Geosciences Rennes (CNRS/UR1 UMR 6118) (France); Bossart, P. [Federal Office for Topography, Wabern (Switzerland); Nussbaum, C. [Institut Geotechnique SA, St-Ursanne (Switzerland); Robinet, J.C.; Nguyen, M.T. [EGC Euro-Geomat-Consulting, 45 - Orleans (France); Barnichon, J.D.; Plas, F. [ANDRA - Agence Nationale pour la Gestion des Dechets Radioactifs, 92 - Chatenay Malabry (France); Ghorbani, A.; Cosenza, P.; Florsch, N. [Pierre et Marie Curie Univ., UMR 7619 Sisyphe, 75 - Paris (France); Revil, A.; Jougnot, D. [Aix-Marseille-2, UMR 6635, CNRS-CEREGE, 13 (France); Schmutz, M. [EGID, M. de Montaigne Univ., 33 - Pessac (France); Contrucci, I.; Klein, E. [Institut National de l' Environnement Industriel et des Risques (INERIS), Ecole des Mines de Nancy, 54 - Nancy (France); Cabrera, J.; Ben-Slimane, K.; Rejeb, A.; Matray, J.M.; Savoye, S. [Institut de Radioprotection et de Surete Nucleaire (IRSN), 92 - Fontenay-aux-Roses (France); Maiolino, S. [Ecole Polytechnique, Lab. de Mecanique des Solides, UMR 7649, LMS, 91 - Palaiseau (France); CETE de Lyon/LRPC de Lyon/Meca Roches/ ERA, 69 - Bron (France); Yong, S.; Loew, S.; Fidelibus, C.; Lemy, F. [Engineering Geology, ETH Zurich, Zurich (Switzerland); Frank, E. [Swiss Federal Nuclear Safety Inspectorate (HSK), Villigen (Switzerland); Chun-Liang, Zhang; Tilmann, Rothfuchs [Gesellschaft fur Anlagen- und Reaktorsicherheit (GRS) mbH, Braunschweig (Germany)

    2007-07-01

    This session gathers 10 articles (posters) dealing with: the influence of bedding planes to EDZ evolution and the coupled HM properties of Opalinus Clay; the electrical tomography monitoring of the EDZ during the excavation of the gallery 04 in the Mont Terri rock laboratory; the seismic endoscopy and tomography of the EDZ of the gallery 04 in the Mont Terri rock laboratory; a elastoplastic damage model for saturated and unsaturated stiffness clays: description and application to the modelling of EDZ around drifts in Callovo-Oxfordian argillites; the non-invasive monitoring of water content and microcracks in argillites using spectral induced polarization; EDZ investigations by ultrasonic borehole logging in drifts of different ages excavated in argillaceous formations of the Tournemire experimental station (Aveyron, France); the excavation damaged zones in the argillaceous Tournemire site: characterisation and failure mechanisms; the hardening-based degradation factor: influence of mean stress and stiffness; the disturbance in the EDZ in the Opalinus clay at Mont Terri; and the experimental study on self-sealing capacity of clay rocks.

  6. Great tits can reduce caterpillar damage in apple orchards

    NARCIS (Netherlands)

    Mols, C.M.M.; Visser, M.E.

    2002-01-01

    1.The potential contribution of vertebrate predators to biological control in orchards has been largely overlooked to date. A few studies have shown that birds reduce numbers of pests, but data are scarce on the effects on the pattern or timing of damage. Consequently, the practical value of birds a

  7. An Approach for Nonlinear Fatigue Damage Evaluation in Asphalt Pavements

    Science.gov (United States)

    Rajbongshi, Pabitra; Thongram, Sonika

    2016-08-01

    Fatigue due to vehicular loads is one of the primary distress mechanisms in asphalt pavements. It happens primarily due to deterioration in asphalt material with load repetitions. Degradation of asphalt material may be evaluated using different parameters. In view of degradation, the incremental damage in a given pavement section would be different for different repetitions, even with same loadings. Therefore, the damage progression becomes nonlinear with repetitions. Accounting such nonlinearity in damage accumulation, and based on different damage evaluation parameters, this paper presents an equivalent approach for fatigue damage evaluation in asphalt pavements. Traditional fatigue equation adopted in mechanistic-empirical pavement design has been used in the present work. Four different criteria, namely number of load repetitions, asphalt stiffness reduction, strain enhancement and fatigue life reduction with repetitions are considered for damage estimation. The proposed approach could estimate same value of nonlinear damage, irrespective of the criteria used. The simplest form of criterion i.e. the number of load repetitions can be used for fatigue performance evaluation. Probabilistically, the damage propagation is also correlated and assessed with the failure probability.

  8. Incorporating damage mechanics into explosion simulation models

    International Nuclear Information System (INIS)

    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

  9. Limiting salt crystallization damage in lime mortar by using crystallization modifiers

    NARCIS (Netherlands)

    Granneman, S.J.C.; Shahidzadeh, N.; Lubelli, B.A.; Hees, R.P.J. van

    2014-01-01

    Salt crystallization is a recurrent cause of damage in porous building materials. Lime-based mortars, which were widely used in construction of ancient masonry, are especially prone to salt damage, due to their low mechanical strength. Existing solutions to tackle salt damage in mortars have been ma

  10. Theoretical study of electronic damage in single particle imaging experiments at XFELs for pulse durations 0.1 - 10 fs

    CERN Document Server

    Gorobtsov, O Yu; Kabachnik, N M; Vartanyants, I A

    2015-01-01

    X-ray free-electron lasers (XFELs) may allow to employ the single particle imaging (SPI) method to determine the structure of macromolecules that do not form stable crystals. Ultrashort pulses of 10 fs and less allow to outrun complete disintegration by Coulomb explosion and minimize radiation damage due to nuclear motion, but electronic damage is still present. The major contribution to the electronic damage comes from the plasma generated in the sample that is strongly dependent on the amount of Auger ionization. Since the Auger process has a characteristic time scale on the order of femtoseconds, one may expect that its contribution will be significantly reduced for attosecond pulses. Here, we study the effect of electronic damage on the SPI at pulse durations from 0.1 fs to 10 fs and in a large range of XFEL fluences to determine optimal conditions for imaging of biological samples. We analyzed the contribution of different electronic excitation processes and found that at fluences higher than $10^{13}$-$...

  11. Biological contexts for DNA charge transport chemistry

    OpenAIRE

    Merino, Edward J.; Boal, Amie K.; Barton, Jacqueline K.

    2008-01-01

    Many experiments have now shown that double helical DNA can serve as a conduit for efficient charge transport (CT) reactions over long distances in vitro. These results prompt the consideration of biological roles for DNA-mediated CT. DNA CT has been demonstrated to occur in biologically relevant environments such as within the mitochondria and nuclei of HeLa cells as well as in isolated nucleosomes. In mitochondria, DNA damage that results from CT is funneled to a critical regulatory element...

  12. AMBIENT PARTICULATE MATTER STIMULATES OXIDATIVE STRESS IN BRAIN MICROGLIA AND DAMAGES NEURONS IN CULTURE.

    Science.gov (United States)

    Ambient particulate matter (PM) damages biological targets through oxidative stress (OS) pathways. Several reports indicate that the brain is one of those targets. Since microglia (brain macrophage) are critical to OS-mediated neurodegeneration, their response to concentrated amb...

  13. 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.

  14. Kombucha Tea Ameliorates Trichloroethylene Induced Hepatic Damages in Rats via Inhibition of Oxidative Stress and Free Radicals Induction

    International Nuclear Information System (INIS)

    Kombucha Tea (KT) is reported to exhibit a wide variety of biological effects, including antioxidant. Evidence shows the important role of oxidative stress in the hepatic damage. The aim of this study is to investigate the possible protective effects of oral administration of KT in rats with trichloroethylene (TCE)-induced damage for ten consecutive days. Hepatic damage was evaluated by measuring total free radicals levels, biochemical and histological examinations. Serum gamma glutamyl transferase (GGT) activity (the hepatic damage marker), total protein, albumin and globulin as well as malonaldehyde (MDA), glutathione (GSH) content, nitric oxide (NO) concentration were evaluated in liver tissue homogenates. Total free radicals concentration in blood was examined by electron spin resonance (ESR). Total protein, DNA concentration, cell number and cell size in liver tissues were also examined. The rats orally administrated with TCE for ten days indicates hepatic damage changes, an increase in blood total free radicals concentration was observed, serum GGT activity, liver MDA, NO levels, total protein and decreased GSH content, DNA concentration and cell number. This accompanied with an increase in cell size of liver tissues, whereas KT reversed these effects. Furthermore, KT inhibits the concentration of total free radicals in blood and decreasing the increment of MDA and NO concentration. Histological studies reveal partial healing in those rats treated by KT after oral administration with TCE. The present results suggest that KT ameliorates TCE induced hepatic damage in rats probably due to its content of glucuronic, acetic acid and B vitamins via inhibition of oxidative stress and total free radicals

  15. A mathematical framework for predicting thermal damage during bone electrostimulation

    NARCIS (Netherlands)

    Vanegas-Acosta, J.C.; Lancellotti, V.; Zwamborn, A.P.M.

    2015-01-01

    Purpose – Electric fields (EFs) are known to influence cell and tissue activity. This influence can be due to thermal or non-thermal effects. While the non-thermal effects are still matter of discussion, thermal effects might be detrimental for cell and tissue viability due to thermal damage, this f

  16. Radiation Damage Workshop

    Science.gov (United States)

    Stella, P. M.

    1984-01-01

    The availability of data regarding the radiation behavior of GaAs and silicon solar cells is discussed as well as efforts to provide sufficient information. Other materials are considered too immature for reasonable radiation evaluation. The lack of concern over the possible catastrophic radiation degradation in cascade cells is a potentially serious problem. Lithium counterdoping shows potential for removing damage in irradiated P-type material, although initial efficiencies are not comparable to current state of the art. The possibility of refining the lithium doping method to maintain high initial efficiencies and combining it with radiation tolerant structures such as thin BSF cells or vertical junction cells could provide a substantial improvement in EOL efficiencies. Laser annealing of junctions, either those formed ion implantation or diffusion, may not only improve initial cell performance but might also reduce the radiation degradation rate.

  17. High laser damage threshold coatings and damage testing technology

    Institute of Scientific and Technical Information of China (English)

    MA Ping; HU Jian-ping; CHEN Song-lin; TANG Ming; WANG Zhen; LI Wei; XU Qiao

    2005-01-01

    The laser-induced damage threshold(LIDT) of optical coating is a limited factor for development of a high peak power laser. The automatic damage testing facility was built to determine the LIDT of optics at 1 064 nm and 355 nm.. The cleanning and processing procedure of the substrate and coating technique were improved, and the damage resistance of high-reflective coating at 1 064 nm was increased.

  18. Biological Databases

    Directory of Open Access Journals (Sweden)

    Kaviena Baskaran

    2013-12-01

    Full Text Available Biology has entered a new era in distributing information based on database and this collection of database become primary in publishing information. This data publishing is done through Internet Gopher where information resources easy and affordable offered by powerful research tools. The more important thing now is the development of high quality and professionally operated electronic data publishing sites. To enhance the service and appropriate editorial and policies for electronic data publishing has been established and editors of article shoulder the responsibility.

  19. 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.

  20. Application of femtosecond-pulsed lasers for direct optical manipulation of biological functions

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jonghee; Park, Junseong; Jong Choi, Won [Department of Bio and Brain Engineering, KAIST, Daejeon (Korea, Republic of); Choi, Myunghwan [Graduate School of Nanoscience and Technology, KAIST, Daejeon (Korea, Republic of); Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA (United States); Choi, Chulhee [Department of Bio and Brain Engineering, KAIST, Daejeon (Korea, Republic of); KAIST Institute for the BioCentury, KAIST, Daejeon (Korea, Republic of)

    2013-03-15

    Absorption of photon energy by cells or tissue can evoke photothermal, photomechanical, and photochemical effects, depending on the density of the deposited energy. Photochemical effects require a low energy density and can be used for reversible modulation of biological functions. Ultrashort-pulsed lasers have a high intensity due to the short pulse duration, despite its low average energy. Through nonlinear absorption, these lasers can deliver very high peak energy into the submicrometer focus area without causing collateral damage. Absorbed energy delivered by ultrashort-pulsed laser irradiation induces free electrons, which can be readily converted to reactive oxygen species (ROS) and related free radicals in the localized region. Free radicals are best known to induce irreversible biological effects via oxidative modification; however, they have also been proposed to modulate biological functions by releasing calcium ions from intracellular organelles. Calcium can evoke variable biological effects in both excitable and nonexcitable cell types. Controlled stimulation by ultrashort laser pulses generate intracellular calcium waves that can modulate many biological functions, such as cardiomyocyte beat rate, muscle contractility, and blood-brain barrier (BBB) permeability. This article presents optical methods that are useful therapeutic and research tools in the biomedical field and discuss the possible mechanisms responsible for biological modulation by ultrashort-pulsed lasers, especially femtosecond-pulsed lasers. (copyright 2012 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Midbroken Reinforced Concrete Shear Frames Due to Earthquakes

    DEFF Research Database (Denmark)

    Köylüoglu, H. U.; Cakmak, A. S.; Nielsen, Søren R. K.

    A non-linear hysteretic model for the response and local damage analyses of reinforced concrete shear frames subject to earthquake excitation is proposed, and, the model is applied to analyse midbroken reinforced concrete (RC) structures due to earthquake loads. Each storey of the shear frame...

  2. Numerical analysis of impact-damaged sandwich composites

    Science.gov (United States)

    Hwang, Youngkeun

    Sandwich structures are used in a wide variety of structural applications due to their relative advantages over other conventional structural materials in terms of improved stability, weight savings, and ease of manufacture and repair. Foreign object impact damage in sandwich composites can result in localized damage to the facings, core, and core-facing interface. Such damage may result in drastic reductions in composite strength, elastic moduli, and durability and damage tolerance characteristics. In this study, physically-motivated numerical models have been developed for predicting the residual strength of impact-damaged sandwich composites comprised of woven-fabric graphite-epoxy facesheets and Nomex honeycomb cores subjected to compression-after-impact loading. Results from non-destructive inspection and destructive sectioning of damaged sandwich panels were used to establish initial conditions for damage (residual facesheet indentation, core crush dimension, etc.) in the numerical analysis. Honeycomb core crush test results were used to establish the nonlinear constitutive behavior for the Nomex core. The influence of initial facesheet property degradation and progressive loss of facesheet structural integrity on the residual strength of impact-damaged sandwich panels was examined. The influence of damage of various types and sizes, specimen geometry, support boundary conditions, and variable material properties on the estimated residual strength is discussed. Facesheet strains from material and geometric nonlinear finite element analyses correlated relatively well with experimentally determined values. Moreover, numerical predictions of residual strength are consistent with experimental observations. Using a methodology similar to that presented in this work, it may be possible to develop robust residual strength estimates for complex sandwich composite structural components with varying levels of in-service damage. Such studies may facilitate sandwich

  3. Damage Behavior of Sintered Fiber Felts

    Directory of Open Access Journals (Sweden)

    Nicolas Lippitz

    2015-04-01

    Full Text Available The reduction of aircraft noise is important due to a rising number of flights and the growth of urban centers close to airports. During landing, a significant part of the noise is generated by flow around the airframe. To reduce that noise porous trailing edges are investigated. Ideally, the porous materials should to be structural materials as well. Therefore, the mechanical properties and damage behavior are of major interest. The aim of this study is to show the change of structure and the damage behavior of sintered fiber felts, which are promising materials for porous trailing edges, under tensile loading using a combination of tensile tests and three dimensional computed tomography scans. By stopping the tensile test after a defined stress or strain and scanning the sample, it is possible to correlate structural changes and the development of damage to certain features in the stress-strain curve and follow the damage process with a high spatial resolution. Finally, the correlation between material structure and mechanical behavior is demonstrated.

  4. [Biologics and mycobacterial diseases].

    Science.gov (United States)

    Tsuyuguchi, Kazunari; Matsumoto, Tomoshige

    2013-03-01

    relationship between RA and nontuberculous mycobacterial (NTM) diseases were discussed, which is still poorly understood. It is well known that airway diseases often accompany RA, which may be considered as a possible etiology for development of NTM diseases, but conversely it may lead to overdiagnosis of NTM disease. Next, we evaluated justification for the contraindication of biologics in patients with NTM diseases. Recent multicenter study showed that prognosis of patients developing NTM diseases during treatment with biologics were not always poor, which throws doubt on uniform prohibition of biologics in NTM diseases. 3. Future guideline for treating latent tuberculosis infection: Seiya KATO (Research Institute of Tuberculosis, Japan AntiTuberculosis Association) The Japanese Society for Tuberculosis issued a joint statement on chemoprophylaxis with the Japan College of Rheumatology in 2004. However, issues and challenges due to changing circumstance indicate application of interferon gamma release assay (IGRA), increased variety and indication of biologics, dissemination of knowledge on strategy and system for latent tuberculosis infection (LTBI), etc. Future guideline should include 1) promoting LTBI treatment to achieve low incidence, 2) updated information on IGRAs, 3) treatment strategy and target: contact to infectious cases, immunosuppressive cases (especially HIV and patients treated with biologics), high risk groups, etc. 4) fundamental information on tuberculosis control strategies, especially DOTS. 4. Therapy for RA and tuberculosis in patients with RA and TB activated by anti-TNF treatment: Tomoshige MATSUMOTO (Osaka Prefectural Medical Center for Respiratory and Allergic Diseases) Biologics targeting TNF, including infliximab, have brought about a paradigm shift in the treatment of rheumatoid arthritis (RA). In 2001, tuberculosis, an ancient and also modem scourge, became spotlighted again, because Keane reported in the New England Journal of Medicine that

  5. Damage tolerance assessment of composite sandwich panels with localised damage

    OpenAIRE

    Zenkert, Dan; Shipsha, Andrey; Bull, Peter; Hayman, Brian

    2005-01-01

    The work described herein is part of a larger context in which the effect of damage in sandwich composite structures for marine applications has been investigated. The overall aim of this effort has been twofold: to develop and verify existing damage assessment models to be used to assess the effect of damage on marine sandwich structures, and to develop a damage assessment scheme to be used by shipyards, ship owners and navies. More specifically, this paper presents a sub-set of this overall...

  6. Evolutionary Tradeoffs between Economy and Effectiveness in Biological Homeostasis Systems

    OpenAIRE

    Pablo Szekely; Hila Sheftel; Avi Mayo; Uri Alon

    2013-01-01

    Biological regulatory systems face a fundamental tradeoff: they must be effective but at the same time also economical. For example, regulatory systems that are designed to repair damage must be effective in reducing damage, but economical in not making too many repair proteins because making excessive proteins carries a fitness cost to the cell, called protein burden. In order to see how biological systems compromise between the two tasks of effectiveness and economy, we applied an approach ...

  7. I know what you did last summer - High resolution mapping of wild boar damages with drones

    OpenAIRE

    Michez, Adrien; Morelle, Kevin; Lehaire, François; Widar, Jérôme; Lejeune, Philippe

    2014-01-01

    Wild boar ability to cause important damages to agricultural lands is not anymore to be demonstrated. These damages often raise conflicts between farmers and hunters due to the associated economic losses. Objective and accurate method for real impact assessment of losses suffered by farmers is thus needed. Currently,in Wallonia damage assessment is performed from the ground by experts, asked to evaluate precisely the area impacted. This task is time and man power consuming. Moreover, damaged ...

  8. A Three-Parameter S-Shaped Function of Flood Return Period and Damage

    OpenAIRE

    Chaochao Li; Xiaotao Cheng; Na Li; Zhongmin Liang; Yanyan Wang; Song Han

    2016-01-01

    With growing flood risk due to increased urbanization, flood damage assessment and flood risk management must be reconsidered. To demonstrate and assess the new features and trends of flood risk in urbanized areas, a novel S-shaped function of return period and damage (R-D) is proposed. The function contains three parameters, which are defined as the maximum flood damage A, critical return period Rc, and integrated loss coefficient k. A basic framework for flood damage assessment was establis...

  9. Biological biomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Jorge-Herrero, E. [Servicio de Cirugia Experimental. Clinica Puerta de Hierro, Madrid (Spain)

    1997-05-01

    There are a number of situations in which substances of biological origin are employed as biomaterials. Most of them are macromolecules derived from isolated connective tissue or the connective tissue itself in membrane form, in both cases, the tissue can be used in its natural form or be chemically treated. In other cases, certain blood vessels can be chemically pretreated and used as vascular prostheses. Proteins such as albumin, collagen and fibrinogen are employed to coat vascular prostheses. Certain polysaccharides have also been tested for use in controlled drug release systems. Likewise, a number of tissues, such as dura mater, bovine pericardium, procine valves and human valves, are used in the preparation of cardiac prostheses. We also use veins from animals or humans in arterial replacement. In none of these cases are the tissues employed dissimilar to the native tissues as they have been chemically modified, becoming a new bio material with different physical and biochemical properties. In short, we find that natural products are being utilized as biomaterials and must be considered as such; thus, it is necessary to study both their chemicobiological and physicomechanical properties. In the present report, we review the current applications, problems and future prospects of some of these biological biomaterials. (Author) 84 refs.

  10. DEVELOPMENT OF PHOTO MANAGEMENT SYSTEM FOR BUILDING DAMAGE ASSESSMENT

    Science.gov (United States)

    Fujiu, Makoto; Numada, Muneyoshi; Ohara, Miho; Meguro, Kimiro

    In Japan, several big earthquakes are expected to occur in the near future. A lot of structural damages due to these earthquakes will cause enormous needs for building damage assessment. In this paper, a system for supporting administrative staffs was designed and photo management system (PhotoMas) was developed in Miyagi prefecture during the 2011 off the Pacific coast of Tohoku earthquake. The system for management some photos of damaged houses and some database which managed local governmant was developed based on Excel VBA. This system makes easier to search photos which are taken by inspector in damaged area, and the system can visually confirm the percentage of completion of building damage assessment.

  11. Immunocosmeceuticals: An emerging trend in repairing human hair damage

    Directory of Open Access Journals (Sweden)

    Karthika Selvan

    2013-01-01

    Full Text Available Hair is one of the most important portions for beauty care and in recent years grooming and cosmetic treatment of hair has drastically risen. Substantially, it may deteriorate and weaken the hair by modification of keratin protein. This makes the hair dry, brittle and split vend occurs due to loss of hair strength and the damage further increases with cosmetic treatments. The various poor ingredients are being used for repairing which have extremely poor compatibility with hair. Now the hair care products can be introduced with an active ingredient comprising a yolk derived anti-hair antibody immunoglobin obtained from egg of chickens immunized with damaged hair as antigen. This immuno-cosmeceuticals can repair the hair damage and imparts flexibility and smoothness to the hair. These effects are not lost by the ordinary shampooing. This article focuses on the characteristic of human hair, its damaging processes and the effects of immuno-cosmeceuticals for repairing the hair damage.

  12. Vibration characteristics and damage detection in a suspension bridge

    Science.gov (United States)

    Wickramasinghe, Wasanthi R.; Thambiratnam, David P.; Chan, Tommy H. T.; Nguyen, Theanh

    2016-08-01

    Suspension bridges are flexible and vibration sensitive structures that exhibit complex and multi-modal vibration. Due to this, the usual vibration based methods could face a challenge when used for damage detection in these structures. This paper develops and applies a mode shape component specific damage index (DI) to detect and locate damage in a suspension bridge with pre-tensioned cables. This is important as suspension bridges are large structures and damage in them during their long service lives could easily go un-noticed. The capability of the proposed vibration based DI is demonstrated through its application to detect and locate single and multiple damages with varied locations and severity in the cables of the suspension bridge. The outcome of this research will enhance the safety and performance of these bridges which play an important role in the transport network.

  13. An improved damaging model for structured clays

    Institute of Scientific and Technical Information of China (English)

    姜岩; 雷华阳; 郑刚; 徐舜华

    2008-01-01

    An improved damaging model formulated within the framework of bounding surface for structured clays was proposed. The model was intended to describe the effects of structure degradation due to geotechnical loading. The predictive capability of the model was compared with those of triaxial compression test on Tianjin soft clays. The results show that, by incorporating a new damage function into the model, the reduction of elastic bulk and shear modulus with elastic deformations and the reduction of plastic bulk modulus and shear modulus with plastic deformations are able to be appreciable. Before the axial strain reaches 15%, the axial strain computed from the model is smaller than that from the test under the drained condition. Under the undrained condition, after the axial strain reaches 1%, the axial strain increases quickly because of the complete loss of structure and stiffness; and the result computed from the model is nearly equal to that from the model without the incorporation of the damage function due to less plastic strain under undrained condition test.

  14. Continuum theory of fibrous tissue damage mechanics using bond kinetics: application to cartilage tissue engineering.

    Science.gov (United States)

    Nims, Robert J; Durney, Krista M; Cigan, Alexander D; Dusséaux, Antoine; Hung, Clark T; Ateshian, Gerard A

    2016-02-01

    This study presents a damage mechanics framework that employs observable state variables to describe damage in isotropic or anisotropic fibrous tissues. In this mixture theory framework, damage is tracked by the mass fraction of bonds that have broken. Anisotropic damage is subsumed in the assumption that multiple bond species may coexist in a material, each having its own damage behaviour. This approach recovers the classical damage mechanics formulation for isotropic materials, but does not appeal to a tensorial damage measure for anisotropic materials. In contrast with the classical approach, the use of observable state variables for damage allows direct comparison of model predictions to experimental damage measures, such as biochemical assays or Raman spectroscopy. Investigations of damage in discrete fibre distributions demonstrate that the resilience to damage increases with the number of fibre bundles; idealizing fibrous tissues using continuous fibre distribution models precludes the modelling of damage. This damage framework was used to test and validate the hypothesis that growth of cartilage constructs can lead to damage of the synthesized collagen matrix due to excessive swelling caused by synthesized glycosaminoglycans. Therefore, alternative strategies must be implemented in tissue engineering studies to prevent collagen damage during the growth process.

  15. Damage in Fiber Bundle Models

    OpenAIRE

    Kun, Ferenc; Zapperi, Stefano; Herrmann, Hans J.

    1999-01-01

    We introduce a continuous damage fiber bundle model that gives rise to macroscopic plasticity and compare its behavior with that of dry fiber bundles. Several interesting constitutive behaviors are found in this model depending on the value of the damage parameter and on the form of the disorder distribution. In addition, we compare the behavior of global load transfer models with local load transfer models and study in detail the damage evolution before failure. We emphasize the analogies be...

  16. Crater Formation Due to Lunar Plume Impingement

    Science.gov (United States)

    Marsell, Brandon

    2011-01-01

    Thruster plume impingement on a surface comprised of small, loose particles may cause blast ejecta to be spread over a large area and possibly cause damage to the vehicle. For this reason it is important to study the effects of plume impingement and crater formation on surfaces like those found on the moon. Lunar soil, also known as regolith, is made up of fine granular particles on the order of 100 microns.i Whenever a vehicle lifts-off from such a surface, the exhaust plume from the main engine will cause the formation of a crater. This crater formation may cause laterally ejected mass to be deflected and possibly damage the vehicle. This study is a first attempt at analyzing the dynamics of crater formation due to thruster exhaust plume impingement during liftoff from the moon. Though soil erosion on the lunar surface is not considered, this study aims at examining the evolution of the shear stress along the lunar surface as the engine fires. The location of the regions of high shear stress will determine where the crater begins to form and will lend insight into how big the crater will be. This information will help determine the probability that something will strike the vehicle. The final sections of this report discuss a novel method for studying this problem that uses a volume of fluid (VOF)ii method to track the movement of both the exhaust plume and the eroding surface.

  17. Biological Effects on Fruit Fly by N+ ion Beam Implantation

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Mutation induced by low energy ion beam implantation has beenapplied widely both in plants and microbes. However, due to the vacuum limitation, such ion implantation into animals was never studied except for silkworm. In this study, Pupae of fruit fly were irradiated with different dosage N+ ions at energy 20 KeV to study the biological effect of ion beam on animal. The results showed a saddle-like curve exists between incubate rate and dosage. Damage of pupae by ion beam implantation was observed using scanning electron microscope. Some individuals with incomplete wing were obtained after implantation but no similar character was observed in their offspring. Furthermore, about 5.47% mutants with wide variation appeared in M1 generation. Therefore, ion beam implantation could be widely used for mutation breeding.

  18. Damage Assessment of Composite Plate Structures with Uncertainty

    OpenAIRE

    M, Chandrashekhar; Ganguli, Ranjan

    2014-01-01

    International audience Uncertainties associated with a structural model and measured vibration data may lead to unreliable damage detection. Two similar structures made from composite materials can display very different dynamic behavior due to large uncertainties associated with composite material properties. In this paper, we show that material uncertainties in composite structures cause considerable problem in damage assessment which can be alleviated by using a fuzzy logic-based approa...

  19. Wavelet Transformation for Damage Identication in Wind Turbine Blades

    DEFF Research Database (Denmark)

    Ulriksen, Martin Dalgaard; Skov, Jonas falk; Kirkegaard, Poul Henning;

    2014-01-01

    The present paper documents a proposed modal and wavelet analysis-based structural health monitoring (SHM) method for damage identification in wind turbine blades. A finite element (FE) model of a full-scale wind turbine blade is developed and introduced to a transverse surface crack. Hereby, post...... of the first structural blade mode. However, due to the nature of the proposed method, it is also found that the accuracy of the damage assessment highly depends on the number of employed measurement points....

  20. Spatial Dependencies in Wind-related Housing Damage

    OpenAIRE

    De Silva, Dakshina G.; Jamie B. Kruse; Wang, Yongsheng

    2008-01-01

    This article examines the spatial dependence among housing losses due to tornadoes using data from the May 1999 Oklahoma City tornado. In order to examine the existence of spatial dependence and its impacts on the damage analysis, we compare an estimation based on a traditional ordinary least square model with the general spatial model. The results show that housing damage in this disaster area is highly correlated. Monetary losses not only depend on the tornado that struck residences, but ar...

  1. Quercitrin Protects Skin from UVB-induced Oxidative Damage

    OpenAIRE

    Yin, Yuanqin; Li, Wenqi; Son, Yong-Ok; SUN, Lijuan; LU, Jian; Kim, Donghern; Wang, Xin; Yao, Hua; Wang, Lei; Pratheeshkumar, Poyil; Hitron, Andrew J; Luo, Jia; Gao, Ning; Shi, Xianglin; Zhang, Zhuo

    2013-01-01

    Exposure of the skin to ultraviolet B (UVB) radiation causes oxidative damage to skin, resulting in sunburn, photoaging, and skin cancer. It is generally believed that the skin damage induced by UV irradiation is a consequence of generation of reactive oxygen species (ROS). Recently, there is an increased interest in the use of natural products as chemopreventive agents for non-melanoma skin cancer (NMSC) due to their antioxidants and anti-inflammatory properties. Quercitrin, glycosylated for...

  2. Applications—Influence of Biology on Engineering

    Institute of Scientific and Technical Information of China (English)

    Julian F. V. Vincent

    2006-01-01

    Examples are presented showing the way in which biological systems produce a range of functions which can be implemented in engineering, such as feedback-control of stiffness (muscles and nervous system), the design of fault-free structures (trees) and damage-tolerant materials (wood) and high performance insulation (penguin feathers) and shock absorbers (hedgehog spines).

  3. Damage control productivity : an input damage abatement approach

    NARCIS (Netherlands)

    Oude Lansink, A.G.J.M.; Carpentier, A.

    2001-01-01

    This paper compares the value of the marginal product of three different pesticides from different specifications of the production function. The specifications are the output damage abatement specification proposed by Lichtenberg and Zilberman, a general input damage abatement specification and a t

  4. Study on Plasmid and Damage Induced by Low-energy Neon Ion Irradiation

    Institute of Scientific and Technical Information of China (English)

    MaQiufeng; WangXiao; JinGenming; LiWenjian; DangBingrong; XieHongmei; ZhouLibin; MaoShuhong

    2003-01-01

    DNA is considered to be the most important and sensitive target in biological systems. Beside base damage, DNA strand breaks are the major lesion in the genome due to exposure to ionizing radiation. Mutation can be introduced to DNA as a result of enzymatic processing of DNA lesions or post-irradiation replication. However, the mechanisms of radiation-induced mutations are not well clarified at the molecular level. A good way to approach the mechanism is to irradiate the plasmid DNA of heavy ion, then transfect the DNA to host cells to determine the mutation spectra. So to study the effect of heavy ions on the simple plasmid DNA is even predominant or more feasible.

  5. A constitutive high cycle fatigue damage model - based on the interaction between microplasticity and local damage

    Energy Technology Data Exchange (ETDEWEB)

    Flaceliere, L. [Futurscope (France); Morel, F.; Dragon, A.

    2006-07-01

    This paper presents a new model that accounts, on a local scale, for the coupling between plasticity due to gliding in shear bands and damage occurring when the accumulated plastic strain has reached a threshold value. The irreversible thermodynamics with internal state variables is employed to keep a middle way between extensive description of plastic and damage flow and application of accessibility requirements. Plasticity and damage are governed by their proper complementary rules (yield functions and potentials). At the same time, a coupling occurs between the damage variable and the hardening parameters. A large experimental database relative to the fatigue behavior of a mild steel C36 submitted to different loading modes (tension, torsion, combined proportional tension and torsion) proves the efficiency of such a model. The prediciton of Woehler curves for cyclic complex stress states can be readily done, but the main feature of this approach is to ensure a clear link between mesoscopic parameters like the hardening behavior of individual grains and the subsequent local damage.

  6. Damage localization using experimental modal parameters and topology optimization

    Science.gov (United States)

    Niemann, Hanno; Morlier, Joseph; Shahdin, Amir; Gourinat, Yves

    2010-04-01

    This work focuses on the development of a damage detection and localization tool using the topology optimization feature of MSC.Nastran. This approach is based on the correlation of a local stiffness loss and the change in modal parameters due to damages in structures. The loss in stiffness is accounted by the topology optimization approach for updating undamaged numerical models towards similar models with embedded damages. Hereby, only a mass penalization and the changes in experimentally obtained modal parameters are used as objectives. The theoretical background for the implementation of this method is derived and programmed in a Nastran input file and the general feasibility of the approach is validated numerically, as well as experimentally by updating a model of an experimentally tested composite laminate specimen. The damages have been introduced to the specimen by controlled low energy impacts and high quality vibration tests have been conducted on the specimen for different levels of damage. These supervised experiments allow to test the numerical diagnosis tool by comparing the result with both NDT technics and results of previous works (concerning shifts in modal parameters due to damage). Good results have finally been achieved for the localization of the damages by the topology optimization.

  7. A CONTINUUM DAMAGE MODEL OF AGING CONCRETE

    Institute of Scientific and Technical Information of China (English)

    Zhao Zhenyang; Xie Huicai; Xu Tao; Yu Jie; Cai Changan

    2001-01-01

    There is up to now no constitutive model in the current theories of CDM that could give a description for the degradation of aging concrete. The two internal state variables β and ω are introduced in this paper. β is called cohesion variable as an additional kinematic parameter, reflecting the cohesion state among material particles. ω is called damage factor for micro-defects such as voids.Then a damage model and a series of constitutive equations are developed on Continuum Mechanics.The model proposed could give a valid description for the whole-course-degradation of aging concrete due tochemical and mechanical actions. Finally, the validity of the model is evaluated by an example and experimental results.

  8. In situ SEM damage mechanisms investigation of short glass fiber reinforced polyamide composite

    OpenAIRE

    ARIF, Muhamad Fatikul; DESPRINGRE, Nicolas; CHEMISKY, Yves; Robert, Gilles; Meraghni, Fodil

    2013-01-01

    Injection molded polyamide composite reinforced with short glass fibers has been widely used in automotive industry due to its high strength to weight ratio and the ability of injection process to produce complex parts. A reliable design of components made of this composite should consider the development of progressive properties degradation due to the damage. A better understanding of the damage mechanisms shall contribute to a better formulation of local damage criteria and thus to include...

  9. Creating biological nanomaterials using synthetic biology

    International Nuclear Information System (INIS)

    Synthetic biology is a new discipline that combines science and engineering approaches to precisely control biological networks. These signaling networks are especially important in fields such as biomedicine and biochemical engineering. Additionally, biological networks can also be critical to the production of naturally occurring biological nanomaterials, and as a result, synthetic biology holds tremendous potential in creating new materials. This review introduces the field of synthetic biology, discusses how biological systems naturally produce materials, and then presents examples and strategies for incorporating synthetic biology approaches in the development of new materials. In particular, strategies for using synthetic biology to produce both organic and inorganic nanomaterials are discussed. Ultimately, synthetic biology holds the potential to dramatically impact biological materials science with significant potential applications in medical systems. (review)

  10. Creating biological nanomaterials using synthetic biology

    Directory of Open Access Journals (Sweden)

    MaryJoe K Rice

    2014-01-01

    Full Text Available Synthetic biology is a new discipline that combines science and engineering approaches to precisely control biological networks. These signaling networks are especially important in fields such as biomedicine and biochemical engineering. Additionally, biological networks can also be critical to the production of naturally occurring biological nanomaterials, and as a result, synthetic biology holds tremendous potential in creating new materials. This review introduces the field of synthetic biology, discusses how biological systems naturally produce materials, and then presents examples and strategies for incorporating synthetic biology approaches in the development of new materials. In particular, strategies for using synthetic biology to produce both organic and inorganic nanomaterials are discussed. Ultimately, synthetic biology holds the potential to dramatically impact biological materials science with significant potential applications in medical systems.

  11. Biological measurement beyond the quantum limit

    CERN Document Server

    Taylor, Michael A; Daria, Vincent; Knittel, Joachi; Hage, Boris; Bachor, Hans-A; Bowen, Warwick P

    2012-01-01

    Quantum noise places a fundamental limit on the per photon sensitivity attainable in optical measurements. This limit is of particular importance in biological measurements, where the optical power must be constrained to avoid damage to the specimen. By using non-classically correlated light, we demonstrated that the quantum limit can be surpassed in biological measurements. Quantum enhanced microrheology was performed within yeast cells by tracking naturally occurring lipid granules with sensitivity 2.4 dB beyond the quantum noise limit. The viscoelastic properties of the cytoplasm could thereby be determined with a 64% improved measurement rate. This demonstration paves the way to apply quantum resources broadly in a biological context.

  12. Shock Initiation of Damaged Explosives

    Energy Technology Data Exchange (ETDEWEB)

    Chidester, S K; Vandersall, K S; Tarver, C M

    2009-10-22

    Explosive and propellant charges are subjected to various mechanical and thermal insults that can increase their sensitivity over the course of their lifetimes. To quantify this effect, shock initiation experiments were performed on mechanically and thermally damaged LX-04 (85% HMX, 15% Viton by weight) and PBX 9502 (95% TATB, 5% Kel-F by weight) to obtain in-situ manganin pressure gauge data and run distances to detonation at various shock pressures. We report the behavior of the HMX-based explosive LX-04 that was damaged mechanically by applying a compressive load of 600 psi for 20,000 cycles, thus creating many small narrow cracks, or by cutting wedge shaped parts that were then loosely reassembled, thus creating a few large cracks. The thermally damaged LX-04 charges were heated to 190 C for long enough for the beta to delta solid - solid phase transition to occur, and then cooled to ambient temperature. Mechanically damaged LX-04 exhibited only slightly increased shock sensitivity, while thermally damaged LX-04 was much more shock sensitive. Similarly, the insensitive explosive PBX 9502 was mechanically damaged using the same two techniques. Since PBX 9502 does not undergo a solid - solid phase transition but does undergo irreversible or 'rachet' growth when thermally cycled, thermal damage to PBX 9502 was induced by this procedure. As for LX-04, the thermally damaged PBX 9502 demonstrated a greater shock sensitivity than mechanically damaged PBX 9502. The Ignition and Growth reactive flow model calculated the increased sensitivities by igniting more damaged LX-04 and PBX 9502 near the shock front based on the measured densities (porosities) of the damaged charges.

  13. Biologic therapy of rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Damjanov Nemanja

    2009-01-01

    Full Text Available Rheumatoid arthritis (RA and juvenile idiopathic/rheumatoid arthritis (JIA are chronic, inflammatory, systemic, auto-immune diseases characterized by chronic arthritis leading to progressive joint erosions. The individual functional and social impact of rheumatoid arthritis is of great importance. Disability and joint damage occur rapidly and early in the course of the disease. The remarkably improved outcomes have been achieved initiating biologic therapy with close monitoring of disease progression. Biologic agents are drugs, usually proteins, which can influence chronic immune dysregulation resulting in chronic arthritis. According to the mechanism of action these drugs include: 1 anti-TNF drugs (etanercept, infiximab, adalimumab; 2 IL-1 blocking drugs (anakinra; 3 IL-6 blocking drugs (tocilizumab; 4 agents blocking selective co-stimulation modulation (abatacept; 5 CD 20 blocking drugs (rituximab. Biologics targeting TNF-alpha with methotrexate have revolutionized the treatment of RA, producing significant improvement in clinical, radiographic, and functional outcomes not seen previously. The new concept of rheumatoid arthritis treatment defines early diagnosis, early aggressive therapy with optimal doses of disease modifying antirheumatic drugs (DMARDs and, if no improvement has been achieved during six months, early introduction of biologic drugs. The three-year experience of biologic therapy in Serbia has shown a positive effect on disease outcome.

  14. Modelling of creep damage development in ferritic steels

    Energy Technology Data Exchange (ETDEWEB)

    Sandstroem, R. [Swedish Institute for Metals Research, Stockholm (Sweden)

    1998-12-31

    The physical creep damage, which is observed in fossil-fired power plants, is mainly due to the formation of cavities and their interaction. It has previously been demonstrated that both the nucleation and growth of creep cavities can be described by power functions in strain for low alloy and 12 % CrMoV creep resistant steels. It possible to show that the physical creep damage is proportional to the product of the number of cavities and their area. Hence, the physical creep damage can also be expressed in terms of the creep strain. In the presentation this physical creep damage is connected to the empirical creep damage classes (1-5). A creep strain-time function, which is known to be applicable to low alloy and 12 % CrMoV creep resistant steels, is used to describe tertiary creep. With this creep strain - time model the residual lifetime can be predicted from the observed damage. For a given damage class the remaining life is directly proportional to the service time. An expression for the time to the next inspection is proposed. This expression is a function of fraction of the total allowed damage, which is consumed till the next inspection. (orig.) 10 refs.

  15. Automated system for laser damage testing of coated optics

    Science.gov (United States)

    Ness, Dale C.; Streater, Alan D.

    2005-12-01

    Research Electro-Optics Inc. (REO) has recently developed a new laser damage testing facility for the purpose of optimizing process parameters for fabrication and coating of high-damage optics. It also enables full or sample qualification of optics with laser damage specifications. The fully automated laser damage testing system uses microscope photography for detection of damage and a 3 ns pulse length 1064 nm laser for irradiation of the sample. It can test and statistically analyze damage events from a large number of shots, enabling large area testing for low probability events. The system measures and maps sizes and locations of damage sites down to a few microns in diameter. The results are not subject to variations due to the human operator. For coatings deposited by ion beam sputtering, small defects (less than 20 microns) are found to be most prevalent at the fluences specified for small optics for the National Ignition Facility. The ability to measure and characterize small defects has improved REO's ability to optimize their processes for making coated optics with high damage thresholds. In addition to qualifying particular parts, the periodic testing also assures that equipment and processes remain optimized.

  16. Mathematics and biology

    International Nuclear Information System (INIS)

    In India and in so many other countries, the science students are generally separated into two main streams: one opting mathematical sciences, the other studying biological sciences. As a result, medicos and biologists have no adequate knowledge of mathematical sciences. It causes a great drawback to them in order to be perfect and updated in their profession, due to the tremendous application of mathematics in bio-sciences, now-a-days. The main aim of this article is to emphasize on the need of the time to produce the mathematico-biologists in abundance for the better service of mankind. (author)

  17. Structural Biology Fact Sheet

    Science.gov (United States)

    ... Home > Science Education > Structural Biology Fact Sheet Structural Biology Fact Sheet Tagline (Optional) Middle/Main Content Area What is structural biology? Structural biology is a field of science focused ...

  18. Chelyabinsk meteoroid entry and airburst damage

    Science.gov (United States)

    Popova, Olga; Emel'yanenko, Vacheslav; Kartashova, Anna; Rybnov, Yurij; Shuvalov, Valery; Jenniskens, Peter; Kharlamov, Vladimir

    The Chelyabinsk airburst of 15 February 2013, was exceptional because of the large kinetic energy of the impacting body and the airburst that was generated, which created significant damage on the ground and numerous injuries in a populated area. The meteor and the effects of the airburst were extraordinarily well documented. Other events with comparable or larger energy in the past century or so include the 1963 August 3 bolide over the south Atlantic, for which only an infrasound signal was recorded, and the famous Tunguska impact in 1908. Estimates of the kinetic energy of the Tunguska impact range from 3 to 50 Mt, due to a lack of good observations at the time. The Chelyabinsk event is much better documented than both, and provides a unique opportunity to calibrate the different approaches used to model meteoroid entry and calculate the damaging effects of its airburst. Being able to predict better the potential damage on the ground from an impending small asteroid impact will help future impact hazard mitigation efforts. In order to be able to model the damaging effects of the Chelyabinsk airburst, the initial kinetic energy and approach trajectory needed to be known, how that energy was dissipated in the atmosphere, and what were the properties of the resulting airburst shockwave. Infrasonic waves are an important source of information about the fireball's initial kinetic energy. Further information about the kinetic energy is derived from the fireball's light curve. Analysis of video observations of the fireball and the shadows movements provided a meteor light curve, deceleration curve and trajectory. Video records also provided time of arrivals of the shockwave and much detail about how that shockwave interacted with surface structures. The extent of the glass damage was mapped by visiting over 50 villages in the area. Meteorites were analysed in a consortium study to understand how their material properties may have contributed to the fragmentation

  19. Genetics of repair of radiation damage to DNA in bacteria

    International Nuclear Information System (INIS)

    The goal of this project is to study the consequences to bacterial DNA of damage by radiation and chemical agents. By correlating the extent of physical and biological damage to DNA, as expressed in various mutants defective in specific DNA repair pathways, we hope to determine mechanisms of biological inactivation of DNA and ways in which the damage can be repaired. We have measured physical damage to DNA in Bacillus subtilis and Escherichia coli by use of alkaline sucrose gradient centrifugation, which indicates the distance between breaks or alkali-labile lesions in single strands of DNA. Biological damage is measured by loss of viability or by loss of transforming activity in treated DNA from B. subtilis, and by the production of sites for DNA repair synthesis by DNA polymerase I (Pol I) in toluene-treated E. coli. We have investigated effects of ultraviolet light (both far-uv and near-uv), ionizing radiation, and selected chemical agents, in the presence or absence of sensitizing or protective agents. A major goal was to characterize DNA repair processes in vivo in B. subtilis. A number of radiation-sensitive mutants were studied, with the result that we have learned a great many details about the repair of DNA in uv-irradiated cells: We have now also studied the induction of methyltransferase in B. subtilis exposed to low concentrations of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). In collaboration with Sankar Mitra and R.S. Foote (Biology Division), we have shown that the basal level of methyltransferase in B. subtilis is about ten-fold higher than in E. coli and that there is about a ten-fold increase during adaptation. Our future studies will focus on the radioprotective effects of alcohols that act as OH radical scavengers but also react to irradiation by the formation of a radical on the carbon alpha to the hydroxyl

  20. Structural Damage in Mexico City

    OpenAIRE

    Hall, John F; Beck, James L.

    1986-01-01

    This paper describes the structural damage in Mexico City caused by the September 19, 1985 earthquake. Photographs which illustrate various features of structural behavior are included. One explanation is presented as to why buildings with fundamental periods of elastic vibration considerably below the predominant two‐second period of the ground motion were most vulnerable to damage.

  1. Grounding Damage to Conventional Vessels

    DEFF Research Database (Denmark)

    Lützen, Marie; Simonsen, Bo Cerup

    2003-01-01

    The present paper is concerned with rational design of conventional vessels with regard to bottom damage generated in grounding accidents. The aim of the work described here is to improve the design basis, primarily through analysis of new statistical data for grounding damage. The current...

  2. Simulating Biological and Non-Biological Motion

    Science.gov (United States)

    Bruzzo, Angela; Gesierich, Benno; Wohlschlager, Andreas

    2008-01-01

    It is widely accepted that the brain processes biological and non-biological movements in distinct neural circuits. Biological motion, in contrast to non-biological motion, refers to active movements of living beings. Aim of our experiment was to investigate the mechanisms underlying mental simulation of these two movement types. Subjects had to…

  3. Biological Literacy in a College Biology Classroom.

    Science.gov (United States)

    Demastes, Sherry; Wandersee, James H.

    1992-01-01

    Examines the proposed definition of biological literacy as the understanding of a small number of pervasive biological principles appropriate to making informed personal and societal decisions. Utilizes the content of a major daily newspaper to adjust biology instruction to focus on this notion of biological literacy. Discusses benefits and…

  4. A Brief Introduction to Chinese Biological Biological

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Chinese Biological Abstracts sponsored by the Library, the Shanghai Institutes for Biological Sciences, the Biological Documentation and Information Network, all of the Chinese Academy of Sciences, commenced publication in 1987 and was initiated to provide access to the Chinese information in the field of biology.

  5. Damage growth in aerospace composites

    CERN Document Server

    2015-01-01

    This book presents novel methods for the simulation of damage evolution in aerospace composites that will assist in predicting damage onset and growth and thus foster less conservative designs which realize the promised economic benefits of composite materials. The presented integrated numerical/experimental methodologies are capable of taking into account the presence of damage and its evolution in composite structures from the early phases of the design (conceptual design) through to the detailed finite element method analysis and verification phase. The book is based on the GARTEUR Research Project AG-32, which ran from 2007 to 2012, and documents the main results of that project. In addition, the state of the art in European projects on damage evolution in composites is reviewed. While the high specific strength and stiffness of composite materials make them suitable for aerospace structures, their sensitivity to damage means that designing with composites is a challenging task. The new approaches describ...

  6. DNA damage in neurodegenerative diseases

    Energy Technology Data Exchange (ETDEWEB)

    Coppedè, Fabio, E-mail: fabio.coppede@med.unipi.it; Migliore, Lucia, E-mail: lucia.migliore@med.unipi.it

    2015-06-15

    Highlights: • Oxidative DNA damage is one of the earliest detectable events in the neurodegenerative process. • The mitochondrial DNA is more vulnerable to oxidative attack than the nuclear DNA. • Cytogenetic damage has been largely documented in Alzheimer's disease patients. • The question of whether DNA damage is cause or consequence of neurodegeneration is still open. • Increasing evidence links DNA damage and repair with epigenetic phenomena. - Abstract: Following the observation of increased oxidative DNA damage in nuclear and mitochondrial DNA extracted from post-mortem brain regions of patients affected by neurodegenerative diseases, the last years of the previous century and the first decade of the present one have been largely dedicated to the search of markers of DNA damage in neuronal samples and peripheral tissues of patients in early, intermediate or late stages of neurodegeneration. Those studies allowed to demonstrate that oxidative DNA damage is one of the earliest detectable events in neurodegeneration, but also revealed cytogenetic damage in neurodegenerative conditions, such as for example a tendency towards chromosome 21 malsegregation in Alzheimer's disease. As it happens for many neurodegenerative risk factors the question of whether DNA damage is cause or consequence of the neurodegenerative process is still open, and probably both is true. The research interest in markers of oxidative stress was shifted, in recent years, towards the search of epigenetic biomarkers of neurodegenerative disorders, following the accumulating evidence of a substantial contribution of epigenetic mechanisms to learning, memory processes, behavioural disorders and neurodegeneration. Increasing evidence is however linking DNA damage and repair with epigenetic phenomena, thereby opening the way to a very attractive and timely research topic in neurodegenerative diseases. We will address those issues in the context of Alzheimer's disease

  7. DNA damage in neurodegenerative diseases

    International Nuclear Information System (INIS)

    Highlights: • Oxidative DNA damage is one of the earliest detectable events in the neurodegenerative process. • The mitochondrial DNA is more vulnerable to oxidative attack than the nuclear DNA. • Cytogenetic damage has been largely documented in Alzheimer's disease patients. • The question of whether DNA damage is cause or consequence of neurodegeneration is still open. • Increasing evidence links DNA damage and repair with epigenetic phenomena. - Abstract: Following the observation of increased oxidative DNA damage in nuclear and mitochondrial DNA extracted from post-mortem brain regions of patients affected by neurodegenerative diseases, the last years of the previous century and the first decade of the present one have been largely dedicated to the search of markers of DNA damage in neuronal samples and peripheral tissues of patients in early, intermediate or late stages of neurodegeneration. Those studies allowed to demonstrate that oxidative DNA damage is one of the earliest detectable events in neurodegeneration, but also revealed cytogenetic damage in neurodegenerative conditions, such as for example a tendency towards chromosome 21 malsegregation in Alzheimer's disease. As it happens for many neurodegenerative risk factors the question of whether DNA damage is cause or consequence of the neurodegenerative process is still open, and probably both is true. The research interest in markers of oxidative stress was shifted, in recent years, towards the search of epigenetic biomarkers of neurodegenerative disorders, following the accumulating evidence of a substantial contribution of epigenetic mechanisms to learning, memory processes, behavioural disorders and neurodegeneration. Increasing evidence is however linking DNA damage and repair with epigenetic phenomena, thereby opening the way to a very attractive and timely research topic in neurodegenerative diseases. We will address those issues in the context of Alzheimer's disease

  8. Manipulation of biological samples using micro and nano techniques

    DEFF Research Database (Denmark)

    Castillo, Jaime; Dimaki, Maria; Svendsen, Winnie Edith

    2009-01-01

    The constant interest in handling, integrating and understanding biological systems of interest for the biomedical field, the pharmaceutical industry and the biomaterial researchers demand the use of techniques that allow the manipulation of biological samples causing minimal or no damage to thei...

  9. Creating biological nanomaterials using synthetic biology

    OpenAIRE

    MaryJoe K Rice; Ruder, Warren C.

    2014-01-01

    Synthetic biology is a new discipline that combines science and engineering approaches to precisely control biological networks. These signaling networks are especially important in fields such as biomedicine and biochemical engineering. Additionally, biological networks can also be critical to the production of naturally occurring biological nanomaterials, and as a result, synthetic biology holds tremendous potential in creating new materials. This review introduces the field of synthetic bi...

  10. An Equilibrium Constitutive Model of Anisotropic Cartilage Damage to Elucidate Mechanisms of Damage Initiation and Progression.

    Science.gov (United States)

    Stender, Michael E; Regueiro, Richard A; Klisch, Stephen M; Ferguson, Virginia L

    2015-08-01

    Traumatic injuries and gradual wear-and-tear of articular cartilage (AC) that can lead to osteoarthritis (OA) have been hypothesized to result from tissue damage to AC. In this study, a previous equilibrium constitutive model of AC was extended to a constitutive damage articular cartilage (CDAC) model. In particular, anisotropic collagen (COL) fibril damage and isotropic glycosaminoglycan (GAG) damage were considered in a 3D formulation. In the CDAC model, time-dependent effects, such as viscoelasticity and poroelasticity, were neglected, and thus all results represent the equilibrium response after all time-dependent effects have dissipated. The resulting CDAC model was implemented in two different finite-element models. The first simulated uniaxial tensile loading to failure, while the second simulated spherical indentation with a rigid indenter displaced into a bilayer AC sample. Uniaxial tension to failure simulations were performed for three COL fibril Lagrangian failure strain (i.e., the maximum elastic COL fibril strain) values of 15%, 30%, and 45%, while spherical indentation simulations were performed with a COL fibril Lagrangian failure strain of 15%. GAG damage parameters were held constant for all simulations. Our results indicated that the equilibrium postyield tensile response of AC and the macroscopic tissue failure strain are highly dependent on COL fibril Lagrangian failure strain. The uniaxial tensile response consisted of an initial nonlinear ramp region due to the recruitment of intact fibrils followed by a rapid decrease in tissue stress at initial COL fibril failure, as a result of COL fibril damage which continued until ultimate tissue failure. In the spherical indentation simulation, damage to both the COL fibril and GAG constituents was located only in the superficial zone (SZ) and near the articular surface with tissue thickening following unloading. Spherical indentation simulation results are in agreement with published experimental

  11. Moisture Risk in Unvented Attics Due to Air Leakage Paths

    Energy Technology Data Exchange (ETDEWEB)

    Prahl, D.; Shaffer, M.

    2014-11-01

    IBACOS completed an initial analysis of moisture damage potential in an unvented attic insulated with closed-cell spray polyurethane foam. To complete this analysis, the research team collected field data, used computational fluid dynamics to quantify the airflow rates through individual airflow (crack) paths, simulated hourly flow rates through the leakage paths with CONTAM software, correlated the CONTAM flow rates with indoor humidity ratios from Building Energy Optimization software, and used Warme und Feuchte instationar Pro two-dimensional modeling to determine the moisture content of the building materials surrounding the cracks. Given the number of simplifying assumptions and numerical models associated with this analysis, the results indicate that localized damage due to high moisture content of the roof sheathing is possible under very low airflow rates. Reducing the number of assumptions and approximations through field studies and laboratory experiments would be valuable to understand the real-world moisture damage potential in unvented attics.

  12. Moisture Risk in Unvented Attics Due to Air Leakage Paths

    Energy Technology Data Exchange (ETDEWEB)

    Prahl, D. [IBACOS, Inc., Pittsburgh, PA (United States); Shaffer, M. [IBACOS, Inc., Pittsburgh, PA (United States)

    2014-11-01

    IBACOS completed an initial analysis of moisture damage potential in an unvented attic insulated with closed-cell spray polyurethane foam. To complete this analysis, the research team collected field data, used computational fluid dynamics to quantify the airflow rates through individual airflow (crack) paths, simulated hourly flow rates through the leakage paths with CONTAM software, correlated the CONTAM flow rates with indoor humidity ratios from Building Energy Optimization software, and used Wärme und Feuchte instationär Pro two-dimensional modeling to determine the moisture content of the building materials surrounding the cracks. Given the number of simplifying assumptions and numerical models associated with this analysis, the results indicate that localized damage due to high moisture content of the roof sheathing is possible under very low airflow rates. Reducing the number of assumptions and approximations through field studies and laboratory experiments would be valuable to understand the real-world moisture damage potential in unvented attics.

  13. Mechanical damage in cotton buds caused by the boll weevil

    Directory of Open Access Journals (Sweden)

    Santos Roseane Cavalcanti

    2003-01-01

    Full Text Available The boll weevil (Anthonomus grandis Boheman causes high levels of bud abscission in cotton plants due to feeding or oviposition punctures. It has been reported that abscission is mainly due to enzymes present in the insect's saliva, but mechanical damage could also contribute to square abscission. The objective of this paper was to undertake an analysis of the morphological damages caused by the insect in cotton squares using microscopy. Anthers and ovules are the main target of boll weevil feeding. The process initiates by perforation of young sepal and petal tissues and proceeds with subsequent alimentation on stamen and ovary leading to abscission of floral structures.

  14. Experimental verification of a progressive damage model for composite laminates based on continuum damage mechanics. M.S. Thesis Final Report

    Science.gov (United States)

    Coats, Timothy William

    1994-01-01

    Progressive failure is a crucial concern when using laminated composites in structural design. Therefore the ability to model damage and predict the life of laminated composites is vital. The purpose of this research was to experimentally verify the application of the continuum damage model, a progressive failure theory utilizing continuum damage mechanics, to a toughened material system. Damage due to tension-tension fatigue was documented for the IM7/5260 composite laminates. Crack density and delamination surface area were used to calculate matrix cracking and delamination internal state variables, respectively, to predict stiffness loss. A damage dependent finite element code qualitatively predicted trends in transverse matrix cracking, axial splits and local stress-strain distributions for notched quasi-isotropic laminates. The predictions were similar to the experimental data and it was concluded that the continuum damage model provided a good prediction of stiffness loss while qualitatively predicting damage growth in notched laminates.

  15. Radiation damage evaluation on concrete within a facility for Selective Production of Exotic Species (SPES Project), Italy

    International Nuclear Information System (INIS)

    Highlights: → We present the effect of radiation on concrete as shielding material. → The coupling between hydro-thermal-mechanical fields and radiation damage is shown. → Attention is focused on numerical modelling of concrete in 3D domains. → A new estimate of the radiation damage parameter is given. → A risk assessment of concrete-radiation interactions is developed. - Abstract: Concrete is commonly used as a biological shield against nuclear radiation. As long as, in the design of nuclear facilities, its load carrying capacity is required together with its shielding properties, changes in the mechanical properties due to nuclear radiation are of particular significance and may have to be taken into account in such circumstances. The study presented here allows for reaching first evidences on the behavior of concrete when exposed to nuclear radiation in order to evaluate the consequent effect on the mechanical field, by means of a proper definition of the radiation damage, strictly connected with the strength properties of the building material. Experimental evidences on the decay of the mechanical modulus of concrete have allowed for implementing the required damage law within a 3D F.E. research code which accounts for the coupling among moisture, heat transfer and the mechanical field in concrete treated as a fully coupled porous medium. The development of the damage front in a concrete shielding wall is analyzed under neutron radiation and results within the wall thickness are reported for long-term radiation spans and several concrete mixtures in order to discuss the resulting shielding properties.

  16. Persistent activation of DNA damage signaling in response to complex mixtures of PAHs in air particulate matter

    Energy Technology Data Exchange (ETDEWEB)

    Jarvis, Ian W.H., E-mail: Ian.Jarvis@ki.se [Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm (Sweden); Bergvall, Christoffer, E-mail: Christoffer.Bergvall@anchem.su.se [Department of Analytical Chemistry, Stockholm University, Svante Arrhenius väg 16, SE-106 91 Stockholm (Sweden); Bottai, Matteo, E-mail: Matteo.Bottai@ki.se [Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm (Sweden); Westerholm, Roger, E-mail: Roger.Westerholm@anchem.su.se [Department of Analytical Chemistry, Stockholm University, Svante Arrhenius väg 16, SE-106 91 Stockholm (Sweden); Stenius, Ulla, E-mail: Ulla.Stenius@ki.se [Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm (Sweden); Dreij, Kristian, E-mail: Kristian.Dreij@ki.se [Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm (Sweden)

    2013-02-01

    Complex mixtures of polycyclic aromatic hydrocarbons (PAHs) are present in air particulate matter (PM) and have been associated with many adverse human health effects including cancer and respiratory disease. However, due to their complexity, the risk of exposure to mixtures is difficult to estimate. In the present study the effects of binary mixtures of benzo[a]pyrene (BP) and dibenzo[a,l]pyrene (DBP) and complex mixtures of PAHs in urban air PM extracts on DNA damage signaling was investigated. Applying a statistical model to the data we observed a more than additive response for binary mixtures of BP and DBP on activation of DNA damage signaling. Persistent activation of checkpoint kinase 1 (Chk1) was observed at significantly lower BP equivalent concentrations in air PM extracts than BP alone. Activation of DNA damage signaling was also more persistent in air PM fractions containing PAHs with more than four aromatic rings suggesting larger PAHs contribute a greater risk to human health. Altogether our data suggests that human health risk assessment based on additivity such as toxicity equivalency factor scales may significantly underestimate the risk of exposure to complex mixtures of PAHs. The data confirms our previous findings with PAH-contaminated soil (Niziolek-Kierecka et al., 2012) and suggests a possible role for Chk1 Ser317 phosphorylation as a biological marker for future analyses of complex mixtures of PAHs. -- Highlights: ► Benzo[a]pyrene (BP), dibenzo[a,l]pyrene (DBP) and air PM PAH extracts were compared. ► Binary mixture of BP and DBP induced a more than additive DNA damage response. ► Air PM PAH extracts were more potent than toxicity equivalency factor estimates. ► Larger PAHs (> 4 rings) contribute more to the genotoxicity of PAHs in air PM. ► Chk1 is a sensitive marker for persistent activation of DNA damage signaling from PAH mixtures.

  17. Subsoil Compaction as a Climate Damage Indicator

    Directory of Open Access Journals (Sweden)

    Márta Birkás

    2009-06-01

    Full Text Available Some forms of soil compaction occur on arable lands both in Hungary (1.82 million ha and in Croatia (0.97 million ha having negative impacts on agricultural production. Tillage-induced subsoil compaction has oft en occurred in the Pannonian region in relation to traffic-induced compaction.Soil compaction has become a soil management problem during the last decade as a result of the occurrence of periods of water-logging as well as droughts. This study contains an evaluation of factors relating to subsoil compaction, as indicator of climate effects on arable fields. This paper is based on soil condition monitoring and measuring that was started 32 years ago and on short and long-term experiments modeling and checking the extension of compaction in the soil. The survey comprised 1526 monitoring places and 38 experimental plots. The following five points were chosen for monitoring: 1 root zone state (to a depth of 0-60 cm; 2 occurrence of compacted layer (indicating likelihood of risk; 3 extension of the compacted layer (indicating the degree of damage; 4 long term effects of tillage (soil state deterioration or improvement, and 5 tillage-induced water-logging and drought damage impacts on yield loss. The main objectives of the experiments were: 1 occurrence and the extent of tillage-pan damage in soils of different susceptibility to compaction; 2 consequences on water management in each of the years covered by the experiments; 3 soil quality consequences, and 4 alleviation of pan-compaction by mechanical and biological methods. Long-term field monitoring and experimental work have both convincingly proven a correlation between subsoil compaction and the degree of climatic damage. In view of the findings, trends in soil tillage can be grouped into the following two categories: climate damage mitigating and climate-stress increasing ones. The formation and location of compacted layers provided information concerning the depth, the method and the

  18. A mechanistic approach to topsoil damage due to slip of tractor tyres

    OpenAIRE

    Battiato, A.; Diserens, E.; Laloui, Lyesse; Sartori, L.

    2013-01-01

    Tractor traction tyres interact with soil by a system of normal and tangential stresses along the soil-tyre contact surface. In this interaction both soil and tyre deform according to their own stress-strain relationships. Soil deformation results in the formation of a rut as well as in topsoil displacement along the soil-tyre contact surface. The topsoil displacement depends on shear stress which soil undergoes at contact with tyre. The shear stress-displacement relationship characterizing t...

  19. Irreversible muscle damage in bodybuilding due to long-term intramuscular oil injection.

    Science.gov (United States)

    Banke, I J; Prodinger, P M; Waldt, S; Weirich, G; Holzapfel, B M; Gradinger, R; Rechl, H

    2012-10-01

    Intramuscular oil injections generating slowly degrading oil-based depots represent a controversial subject in bodybuilding and fitness. However they seem to be commonly reported in a large number of non-medical reports, movies and application protocols for 'site-injections'. Surprisingly the impact of long-term (ab)use on the musculature as well as potential side-effects compromising health and sports ability are lacking in the medical literature. We present the case of a 40 year old male semi-professional bodybuilder with systemic infection and painful reddened swellings of the right upper arm forcing him to discontinue weightlifting. Over the last 8 years he daily self-injected sterilized sesame seed oil at numerous intramuscular locations for the purpose of massive muscle building. Whole body MRI showed more than 100 intramuscular rather than subcutaneous oil cysts and loss of normal muscle anatomy. 2-step septic surgery of the right upper arm revealed pus-filled cystic scar tissue with the near-complete absence of normal muscle. MRI 1 year later revealed the absence of relevant muscle regeneration. Persistent pain and inability to perform normal weight training were evident for at least 3 years post-surgery. This alarming finding indicating irreversible muscle mutilation may hopefully discourage people interested in bodybuilding and fitness from oil-injections. The impact of such chronic tissue stress on other diseases like malignancy remains to be determined.

  20. 厄洛替尼致肝损害%Liver damage due to erlotinib

    Institute of Scientific and Technical Information of China (English)

    白帆; 刘阳; 冯雷

    2013-01-01

    1例表皮生长因子受体阳性的初诊78岁男性肺癌患者接受厄洛替尼150 mg,1次/d口服化疗.化疗前丙氨酸转氨酶(ALT) 12 U/L,天冬氨酸转氨酶(AST) 16 U/L,总胆红素(TBil)22.0μmol/L,直接胆红素(DBil) 7.6 μmol/L.化疗2周复查:ALT 30 U/L,AST 33 U/L,TBil 20.0μmol/L,DBil 6.3 μmol/L.化疗2个月患者出现尿色加深,全身皮肤及巩膜黄染.化疗约75 d实验室检查:ALT 368 U/L,TBil 182.1 μmol/L,DBil 155.2μmol/L.停用厄洛替尼,予保肝治疗.停药第4天,ALT 171 U/L,AST 177 U/L,TBil 322.0μmol/L,DBil 278.2 μmol/L.停药第6天,加用甲泼尼龙.停药第12天,ALT 132 U/L,AST 141 U/L,TBil 172.6 μmol/L,DBil 135.4 μmol/L.停用厄洛替尼2个月,ALT 12 U/L,AST 30U/L,TBil 19.8 μmol/L,DBil 13.5 μmol/L.随后换用吉西他滨联合尼妥珠单抗继续化疗6个疗程,未再出现肝功能异常.%A 78-year-old man,who was newly diagnosed with epidermal growth factor receptorpositive lung cancer,received treatment with oral erlotinib 150 mg once daily.Laboratory test before the chemotherapy showed the following values:alanine aminotransferase (ALT) 12 U/L,aspartate aminotransferase (AST) 16 U/L,total bilirubin (TBil) 22.0 μmol/L,direct bilirubin (DBil) 7.6 μmol/L.Two weeks after chemotherapy treatment,re-examination revealed the following values:ALT 30 U/L,AST 33 U/L,TBil 20.0 μmol/L,DBil 6.3 μmol/L.Two months after chemotherapy,the patient presented with dark urine and yellowish whole skin and sclera.Seventy-five days after the chemotherapy,laboratory test showed the following values:ALT 368 U/L,TBil 182.1 μmol/L,DBil 155.2 μmol/L.Erlotinib was discontinued and liver-protective treatment was given.On day 4 after erlotinib discontinuation,the levels of ALT,AST,TBil,and DBil were 171 U/L,177 U/L,322.0 μmol/L,and 278.2 μmol/L,respectively.On day 6 after erlotinib discontinuation,methylprednisolone was added to his regimen.On day 12 after erlotinib discontinuation,the levels of ALT,AST,TBil,and DBil were 132 U/L,141 U/L,172.6 μmol/L,135.4 μmol/L,respectively.Two months after erlotinib discontinuation,the levels of ALT,AST,TBil,and DBil were 12 U/L,30 U/L,19.8 μmol/L,and 13.5 μmol/L,respectively.Then chemotherapy was switched to 6 cycles of gemcitabine and nimotuzumab and abnormal liver function did not recur.

  1. Irreversible muscle damage in bodybuilding due to long-term intramuscular oil injection.

    Science.gov (United States)

    Banke, I J; Prodinger, P M; Waldt, S; Weirich, G; Holzapfel, B M; Gradinger, R; Rechl, H

    2012-10-01

    Intramuscular oil injections generating slowly degrading oil-based depots represent a controversial subject in bodybuilding and fitness. However they seem to be commonly reported in a large number of non-medical reports, movies and application protocols for 'site-injections'. Surprisingly the impact of long-term (ab)use on the musculature as well as potential side-effects compromising health and sports ability are lacking in the medical literature. We present the case of a 40 year old male semi-professional bodybuilder with systemic infection and painful reddened swellings of the right upper arm forcing him to discontinue weightlifting. Over the last 8 years he daily self-injected sterilized sesame seed oil at numerous intramuscular locations for the purpose of massive muscle building. Whole body MRI showed more than 100 intramuscular rather than subcutaneous oil cysts and loss of normal muscle anatomy. 2-step septic surgery of the right upper arm revealed pus-filled cystic scar tissue with the near-complete absence of normal muscle. MRI 1 year later revealed the absence of relevant muscle regeneration. Persistent pain and inability to perform normal weight training were evident for at least 3 years post-surgery. This alarming finding indicating irreversible muscle mutilation may hopefully discourage people interested in bodybuilding and fitness from oil-injections. The impact of such chronic tissue stress on other diseases like malignancy remains to be determined. PMID:22592548

  2. An assessment of radiation damage in space-based germanium detectors due to solar proton events

    NARCIS (Netherlands)

    Owens, Alan; Brandenburg, S.; Buis, E. -J.; Kliewiet, H.; Kraft, S.; Ostendorf, R. W.; Peacock, A.; Quarati, F.; Quirin, P.

    2007-01-01

    Radiation effects caused by solar proton events will be a common problem for many types of sensors on missions to the inner solar system because of the long cruise phases coupled with the inverse square scaling of solar particle events. As part of a study in support of the BepiColombo mission to Mer

  3. Damage Accumulation in Vertical Breakwaters due to Combined Impact Loading and Pulsating Wave Loads

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Nielsen, Søren R. K.

    1999-01-01

    elasto-plastic oscillator. The pulsating part of the wave loading is modelled as a filtered white noise process, and the impact load is modelled by a filtered Poisson process. It is shown how a distribution function for the accumulated permanent deformations can be obtained. Finally, an illustrative...

  4. Toe Tissue Transfer for Reconstruction of Damaged Digits due to Electrical Burns

    Directory of Open Access Journals (Sweden)

    Hyung-Do Kim

    2012-03-01

    Full Text Available Background Electrical burns are one of the most devastating types of injuries, and can becharacterized by the conduction of electric current through the deeper soft tissue such asvessels, nerves, muscles, and bones. For that reason, the extent of an electric burn is veryfrequently underestimated on initial impression.Methods From July 1999 to June 2006, we performed 15 cases of toe tissue transfer for thereconstruction of finger defects caused by electrical burns. We performed preoperative rangeof motion exercise, early excision, and coverage of the digital defect with toe tissue transfer.Results We obtained satisfactory results in both functional and aesthetic aspects in all 15cases without specific complications. Static two-point discrimination results in the transferredtoe cases ranged from 8 to 11 mm, with an average of 9.5 mm. The mean range of motionof the transferred toe was 20° to 36° in the distal interphalangeal joint, 16° to 45° in theproximal interphalangeal joint, and 15° to 35° in the metacarpophalangeal joint. All of thepatients were relatively satisfied with the function and appearance of their new digits.Conclusions The strategic management of electrical injury to the hands can be both challengingand complex. Because the optimal surgical method is free tissue transfer, maintenance ofvascular integrity among various physiological changes works as a determining factor for thepostoperative outcome following the reconstruction.

  5. Radiation damages due to the Chernobyl accident. The present situations in the exposed area

    International Nuclear Information System (INIS)

    Upon the time of the 10th year after the Chernobyl accident, the present situations of the exposed area in the old USSR were described here based on the author's some experiences at visiting there from 1990 in addition to the evidences obtained from the long lasting studies in Hiroshima. Especially, the influences by the accident on the occurrences of infantile thyroid carcinoma, congenital abnormalities (teratogenesis) and other abnormalities were discussed. Infantile thyroid carcinoma is a rare disease in the world, however, as many as 40 cases have developed in Belarus by Apr. 1991. The author also confirmed the frequent developments of infantile thyroid carcinoma following the accident in other areas exposed to high level isotopes and pointed the pathogenic possibility of 131I. This shows that the nuclide may play a role as an initiation factor in the mechanism of its carcinogenesis. In Minsk Genetic Disease Institute, various data on congenital abnormalities have been collected from 1970 by establishment of their monitoring system. The incidences of congenital abnormalities for 30,000 cases in the postmortem data were compared between the high-level exposed area and no or low-level, leading to the conclusion that the teratogenic rate in the high-level exposed area rapidly increased during 1-2 years after the accident. (M.N.)

  6. Safety of a Commercial Aircraft after Damage to Airframe due to Terrorist Attack

    OpenAIRE

    Lošťák, Miroslav

    2012-01-01

    Teroristické útoky znamenají dnes velké nebezpečí pro civilní dopravní letouny. V této práci jsou analyzovány možné způsoby útoků a je vybrán nejnebezpečnější. Jedná se o teroristický útok z vnějšku letounu za použití tříštivé bojové hlavice rakety. Tato bojová hlavice působí poškození draku letounu rojem střepin vzniklých při výbuchu. Je definován způsob určení zasažené plochy letounu za použití analytické geometrie. Analytickými rovnicemi jsou popsány geometrie rozptylu střepin a geometrie ...

  7. CT findings and prognoses of anoxic brain damage due to near-drowning in children

    International Nuclear Information System (INIS)

    We investigated the relationship between serial cranial CT findings and prognoses in 11 children after near-drowning. These patients were rescued after heart arrest for more than 10 minutes and all comatose on admission. CT scans were performed within 2 weeks, at 3 weeks-1 month, 2-4 months and more than 5 months after admission. Characteristics of CT findings and prognoses were classified into four groups. Group 1 - low density areas in thalami, basal ganglia and cortical white matters within 2 weeks (three cases; one died, two became vegitative). Group 2 - enlargement of the third ventricle at 3 weeks-1 month, and atrophy of pons at 2-4 months (three cases; severe quadriplegia and mental retardation). Group 3 - enlargement of the third ventricle at 3 weeks-1 month, but atrophy of pons not observed at 2-4 months (three cases; mild motor disabilities and mild mental retardation). Group 4 - enlargement of third ventricle not observed at 3 weeks-1 month (two cases; neither paralysis nor mental retardation). (author)

  8. An assessment of radiation damage in space-based germanium detectors due to solar proton events

    International Nuclear Information System (INIS)

    Radiation effects caused by solar proton events will be a common problem for many types of sensors on missions to the inner solar system because of the long cruise phases coupled with the inverse square scaling of solar particle events. As part of a study in support of the BepiColombo mission to Mercury we have undertaken a comprehensive series of tests to assess these effects on a wide range of sensors. In this paper, we report on the measurements on a large volume coaxial Ge detector which was exposed to simulated solar proton spectra of integrated fluences 8x108, 6x109 and 6x1010protonscm-2. After each irradiation the detectors performance was accessed in terms of energy resolution, efficiency and activation. The detector was then annealed and the measurements repeated before the next irradiation. The minimum operational performance criteria were based on the resolution and efficiency requirements necessary to detect and separate specific radioisotope emission lines from a planetary regolith. Specifically that the energy resolution be restored to 5 keV FWHM at 1332 keV and the detection efficiency be degraded to no more than 10% of its pre-irradiation value. The key conclusion of this study is that even after a modest solar proton event the detector requires extensive annealing. After exposure to an event of integral fluence ∼8x108protonscm-2 this amounts to ∼1 week duration at 1000C, whereas for a fluence of ∼6x1010protonscm-2, the detector requires 3.5 months of annealing to satisfy the minimum operational performance requirements and 4.5 months to return the energy resolution to <3keV FWHM at 1332 keV. As a consequence such an instrument will require constant, planned and active management throughout its operational lifetime. The impact on spacecraft operations including resource management therefore needs careful consideration

  9. Expansive Soil Crack Depth under Cumulative Damage

    Directory of Open Access Journals (Sweden)

    Bei-xiao Shi

    2014-01-01

    Full Text Available The crack developing depth is a key problem to slope stability of the expansive soil and its project governance and the crack appears under the roles of dry-wet cycle and gradually develops. It is believed from the analysis that, because of its own cohesion, the expansive soil will have a certain amount of deformation under pulling stress but without cracks. The soil body will crack only when the deformation exceeds the ultimate tensile strain that causes cracks. And it is also believed that, due to the combined effect of various environmental factors, particularly changes of the internal water content, the inherent basic physical properties of expansive soil are weakened, and irreversible cumulative damages are eventually formed, resulting in the development of expansive soil cracks in depth. Starting from the perspective of volumetric strain that is caused by water loss, considering the influences of water loss rate and dry-wet cycle on crack developing depth, the crack developing depth calculation model which considers the water loss rate and the cumulative damages is established. Both the proposal of water loss rate and the application of cumulative damage theory to the expansive soil crack development problems try to avoid difficulties in matrix suction measurement, which will surely play a good role in promoting and improving the research of unsaturated expansive soil.

  10. Genetic Damage Induced by Accidental Environmental Pollutants

    Directory of Open Access Journals (Sweden)

    Beatriz Pérez-Cadahía

    2006-01-01

    Full Text Available Petroleum is one of the main energy sources worldwide. Its transport is performed by big tankers following some established marine routes. In the last 50 years a total amount of 37 oil tankers have given rise to great spills in different parts of the world, Prestige being the last one. After the accident, a big human mobilisation took place in order to clean beaches, rocks and fauna, trying to reduce the environmental consequences of this serious catastrophe. These people were exposed to the complex mixture of compounds contained in the oil. This study aimed at determine the level of environmental exposure to volatile organic compounds (VOC, and the possible damage induced on the population involved in the different cleaning tasks by applying the genotoxicity tests sister chromatid exchanges (SCE, micronucleus (MN test, and comet assay. Four groups of individuals were included: volunteers (V, hired manual workers (MW, hired high-pressure cleaner workers (HPW and controls. The higher VOC levels were associated with V environment, followed by MW and lastly by HPW, probably due to the use of high-pressure cleaners. Oil exposure during the cleaning tasks has caused an increase in the genotoxic damage in individuals, the comet assay being the most sensitive biomarker to detect it. Sex, age and tobacco consumption have shown to influence the level of genetic damage, while the effect of using protective devices was less noticeable than expected, perhaps because the kind used was not the most adequate.

  11. Biology of infantile hemangioma.

    Science.gov (United States)

    Itinteang, Tinte; Withers, Aaron H J; Davis, Paul F; Tan, Swee T

    2014-01-01

    Infantile hemangioma (IH), the most common tumor of infancy, is characterized by an initial proliferation during infancy followed by spontaneous involution over the next 5-10 years, often leaving a fibro-fatty residuum. IH is traditionally considered a tumor of the microvasculature. However, recent data show the critical role of stem cells in the biology of IH with emerging evidence suggesting an embryonic developmental anomaly due to aberrant proliferation and differentiation of a hemogenic endothelium with a neural crest phenotype that possesses the capacity for endothelial, hematopoietic, mesenchymal, and neuronal differentiation. Current evidence suggests a putative placental chorionic mesenchymal core cell embolic origin of IH during the first trimester. This review outlines the emerging role of stem cells and their interplay with the cytokine niche that promotes a post-natal environment conducive for vasculogenesis involving VEGFR-2 and its ligand VEGF-A and the IGF-2 ligand in promoting cellular proliferation, and the TRAIL-OPG anti-apoptotic pathway in preventing cellular apoptosis in IH. The discovery of the role of the renin-angiotensin system in the biology of IH provides a plausible explanation for the programed biologic behavior and the β-blocker-induced accelerated involution of this enigmatic condition. This crucially involves the vasoactive peptide, angiotensin II, that promotes cellular proliferation in IH predominantly via its action on the ATIIR2 isoform. The role of the RAS in the biology of IH is further supported by the effect of captopril, an ACE inhibitor, in inducing accelerated involution of IH. The discovery of the critical role of RAS in IH represents a novel and fascinating paradigm shift in the understanding of human development, IH, and other tumors in general. PMID:25593962

  12. Damage and repair of ancient DNA

    DEFF Research Database (Denmark)

    Mitchell, David; Willerslev, Eske; Hansen, Anders

    2005-01-01

    , and extensive degradation. In the course of this review, we will discuss the current aDNA literature describing the importance of aDNA studies as they relate to important biological questions and the difficulties associated with extracting useful information from highly degraded and damaged substrates derived......Under certain conditions small amounts of DNA can survive for long periods of time and can be used as polymerase chain reaction (PCR) substrates for the study of phylogenetic relationships and population genetics of extinct plants and animals, including hominids. Because of extensive DNA...... degradation, these studies are limited to species that lived within the past 10(4)-10(5) years (Late Pleistocene), although DNA sequences from 10(6) years have been reported. Ancient DNA (aDNA) has been used to study phylogenetic relationships of protists, fungi, algae, plants, and higher eukaryotes...

  13. Detection of damage in welded structure using experimental modal data

    Science.gov (United States)

    Abu Husain, N.; Ouyang, H.

    2011-07-01

    A typical automotive structure could contain thousands of spot weld joints that contribute significantly to the vehicle's structural stiffness and dynamic characteristics. However, some of these joints may be imperfect or even absent during the manufacturing process and they are also highly susceptible to damage due to operational and environmental conditions during the vehicle lifetime. Therefore, early detection and estimation of damage are important so necessary actions can be taken to avoid further problems. Changes in physical parameters due to existence of damage in a structure often leads to alteration of vibration modes; thus demonstrating the dependency between the vibration characteristics and the physical properties of structures. A sensitivity-based model updating method, performed using a combination of MATLAB and NASTRAN, has been selected for the purpose of this work. The updating procedure is regarded as parameter identification which aims to bring the numerical prediction to be as closely as possible to the measured natural frequencies and mode shapes data of the damaged structure in order to identify the damage parameters (characterised by the reductions in the Young's modulus of the weld patches to indicate the loss of material/stiffness at the damage region).

  14. Detection of damage in welded structure using experimental modal data

    Energy Technology Data Exchange (ETDEWEB)

    Abu Husain, N [Transportation Research Alliance, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor (Malaysia); Ouyang, H, E-mail: nurul@fkm.utm.my, E-mail: h.ouyang@liv.ac.uk [Department of Engineering, Harrison-Hughes Building, University of Liverpool, Brownlow Hill, Liverpool L69 3GH (United Kingdom)

    2011-07-19

    A typical automotive structure could contain thousands of spot weld joints that contribute significantly to the vehicle's structural stiffness and dynamic characteristics. However, some of these joints may be imperfect or even absent during the manufacturing process and they are also highly susceptible to damage due to operational and environmental conditions during the vehicle lifetime. Therefore, early detection and estimation of damage are important so necessary actions can be taken to avoid further problems. Changes in physical parameters due to existence of damage in a structure often leads to alteration of vibration modes; thus demonstrating the dependency between the vibration characteristics and the physical properties of structures. A sensitivity-based model updating method, performed using a combination of MATLAB and NASTRAN, has been selected for the purpose of this work. The updating procedure is regarded as parameter identification which aims to bring the numerical prediction to be as closely as possible to the measured natural frequencies and mode shapes data of the damaged structure in order to identify the damage parameters (characterised by the reductions in the Young's modulus of the weld patches to indicate the loss of material/stiffness at the damage region).

  15. Cell biology perspectives in phage biology.

    Science.gov (United States)

    Ansaldi, Mireille

    2012-01-01

    Cellular biology has long been restricted to large cellular organisms. However, as the resolution of microscopic methods increased, it became possible to study smaller cells, in particular bacterial cells. Bacteriophage biology is one aspect of bacterial cell biology that has recently gained insight from cell biology. Despite their small size, bacteriophages could be successfully labeled and their cycle studied in the host cells. This review aims to put together, although non-extensively, several cell biology studies that recently pushed the elucidation of key mechanisms in phage biology, such as the lysis-lysogeny decision in temperate phages or genome replication and transcription, one step further.

  16. Real-time study of bulk damage formation in glass initiated by intense femtosecond pulses

    Science.gov (United States)

    Kudriašov, V.; Gaižauskas, E.; Sirutkaitis, V.

    2005-12-01

    Dynamics of damage formation by focusing intense femtosecond pulses inside the fused silica glass is studied in wide energy range. Damage usually is initiated in the zone near geometrical focus, which is preceded by the zone where beam propagates in the form of multiple filaments. For high repetition rate pulses damage appears as an extended narrow track along the beam path, which forms due to the propagation of the initial damage zone toward the laser source. For low repetition rate pulses extended damage tracks don't form.

  17. Stimulated Brillouin Scattering Damage of Large-Aperture Fused Silica Grating

    Institute of Scientific and Technical Information of China (English)

    HAN Wei; ZHENG Wan-Guo; HUANG Wan-Qing; LI Ke-Yu; WANG Fang; FENG Bin; JIA Huai-Ting; LI Fu-Quan; XIANG Yong; JING Feng

    2010-01-01

    @@ Laser induced damage experiment fs carried out on a large aperture laser facility.Severe damage is observed on a large-aperture fused silica grating which presents dense craters on the front surface and six cracks alternatively located at the front and the rear surface.The bizarre fact about the damage on the grating is that,unlike other optics,the damage craters are almost on the front surface.According to observation,damage phenomenon is due to the stimulated Brillouin scattering(SBS)effect occurring in the grating,which includes the transverse SBS,the back SBS and the zigzag SBS.

  18. Conducting Due Diligence in China

    Institute of Scientific and Technical Information of China (English)

    CHRIS; DEVONSHIRE-ELLIS

    2008-01-01

    Ninety percent of problems when set- ting up business in China can be avoided by the deployment of due diligence at the front end of the investment planning.Here we point out some of the areas that can hinder a sensible approach to due diligence,the hidden risks and basic checks.The process does not have to be expensive. Land use rights These relate to the status of the land on which your Chinese partner has his prem-

  19. Multiscale physics of ion-induced radiation damage.

    Science.gov (United States)

    Surdutovich, Eugene; Solov'yov, A V

    2014-01-01

    This is a review of a multiscale approach to the physics of ion-beam cancer therapy, an approach suggested in order to understand the interplay of a large number of phenomena involved in the radiation damage scenario occurring on a range of temporal, spatial, and energy scales. We describe different effects that take place on different scales and play major roles in the scenario of interaction of ions with tissue. The understanding of these effects allows an assessment of relative biological effectiveness that relates the physical quantities, such as dose, to the biological values, such as the probability of cell survival.

  20. Radiation-induced damage to DNA

    International Nuclear Information System (INIS)

    This short survey focuses on the main radiation-induced base lesions that have been identified within cellular DNA. For this purpose, sensitive assays that are aimed at measuring a few modifications per 107 normal bases were set-up. In that respect high performance liquid chromatography - tandem mass spectrometry (CLHP-MS/MS) was found to be able to single out the formation of 9 oxidized nucleosides and two modified nucleo-bases out of the 70 oxidative base lesions that have been identified in model systems. As a striking result, it was found that in the DNA of γ-irradiated human monocytes, the formamide-pyrimidine derivative of guanine is produced in a higher yield than the ubiquitous 8-oxo-7,8-dihydro-guanine damage, both arising from the same radical precursor. However, relatively high doses of ionizing radiation (> 20 Gy) have to be applied in order to detect an increase in the level of the damage. This is due to the low efficiency for both low and high LET radiations to generate oxidative damage to DNA on one hand and the occurrence of artifactual oxidation of the overwhelming normal bases during DNA extraction on the other hand. Interestingly, a modified comet assays that involves the combined use of the alkaline single gel electrophoretic technique and DNA repair N-glycosylases has allowed the detection of three main types of radiation-induced damage within the dose range 0.3 Gy -10 Gy. It appears that the total of frank DNA strand breaks and alkali-labile sites is similar to the sum of oxidized pyrimidine bases and modified purine bases that are recognized by the endonuclease Ill protein and the formamide-pyrimidine DNA N-glycosylase respectively. (author)

  1. An Improved Method of Structure Damage Diagnosis for Jacket Platforms

    Institute of Scientific and Technical Information of China (English)

    Juan Liu; Weiping Huang; Xiang Shi

    2011-01-01

    In the exploitation of ocean oil and gas,many offshore structures may be damaged due to the severe environment,so an effective method of diagnosing structural damage is urgently needed to locate the damage and evaluate its severity.Genetic algorithms have become some of the most important global optimization tools and been widely used in many fields in recent years because of their simple operation and strong robustness.Based on the natural frequencies and mode shapes of the structure,the damage diagnosis of a jacket offshore platform is attributed to an optimization problem and studied by using a genetic algorithm.According to the principle that the structural stiffness of a certain direction can be greatly affected only when the brace bar in the corresponding direction is damaged,an improved objective function was proposed in this paper targeting measurement noise and the characteristics of modal identification for offshore platforms.This function can be used as fitness function of a genetic algorithm,and both numerical simulation and physical model test results show that the improved method may locate the structural damage and evaluate the severity of a jacket offshore platform satisfactorily while improving the robustness of evolutionary searching and the reliability of damage diagnosis.

  2. BDS thin film damage competition

    Energy Technology Data Exchange (ETDEWEB)

    Stolz, C J; Thomas, M D; Griffin, A J

    2008-10-24

    A laser damage competition was held at the 2008 Boulder Damage Symposium in order to determine the current status of thin film laser resistance within the private, academic, and government sectors. This damage competition allows a direct comparison of the current state-of-the-art of high laser resistance coatings since they are all tested using the same damage test setup and the same protocol. A normal incidence high reflector multilayer coating was selected at a wavelength of 1064 nm. The substrates were provided by the submitters. A double blind test assured sample and submitter anonymity so only a summary of the results are presented here. In addition to the laser resistance results, details of deposition processes, coating materials, and layer count will also be shared.

  3. Civil Liability for Environmental Damages

    Directory of Open Access Journals (Sweden)

    Daniela Ciochină

    2012-05-01

    Full Text Available We debated in this article the civil liability for environmental damages as stipulated in ourlegislation with reference to Community law. The theory of legal liability in environmental law is basedon the duty of all citizens to respect and protect the environment. Considering the importance ofenvironment in which we live, the liability for environmental damages is treated by the Constitution as aprinciple and a fundamental obligation. Many human activities cause environmental damages and, in linewith the principle of sustainable development, they should be avoided. However, when this is notpossible, they must be regulated (by criminal or administrative law in order to limit their adverse effectsand, according to the polluter pays principle, to internalize in advance their externalities (through taxes,insurances or other forms of financial security products. Communication aims to analyze these issues andlegal regulations dealing with the issue of liability for environmental damage.

  4. Climate change: Unattributed hurricane damage

    Science.gov (United States)

    Hallegatte, Stéphane

    2015-11-01

    In the United States, hurricanes have been causing more and more economic damage. A reanalysis of the disaster database using a statistical method that accounts for improvements in resilience opens the possibility that climate change has played a role.

  5. Probabilistic Fatigue Damage Program (FATIG)

    Science.gov (United States)

    Michalopoulos, Constantine

    2012-01-01

    FATIG computes fatigue damage/fatigue life using the stress rms (root mean square) value, the total number of cycles, and S-N curve parameters. The damage is computed by the following methods: (a) traditional method using Miner s rule with stress cycles determined from a Rayleigh distribution up to 3*sigma; and (b) classical fatigue damage formula involving the Gamma function, which is derived from the integral version of Miner's rule. The integration is carried out over all stress amplitudes. This software solves the problem of probabilistic fatigue damage using the integral form of the Palmgren-Miner rule. The software computes fatigue life using an approach involving all stress amplitudes, up to N*sigma, as specified by the user. It can be used in the design of structural components subjected to random dynamic loading, or by any stress analyst with minimal training for fatigue life estimates of structural components.

  6. Tissue kallikrein-kinin therapy in hypertension and organ damage.

    Science.gov (United States)

    Chao, Julie; Bledsoe, Grant; Chao, Lee

    2014-01-01

    Tissue kallikrein is a serine proteinase that cleaves low molecular weight kininogen to produce kinin peptides, which in turn activate kinin receptors to trigger multiple biological functions. In addition to its kinin-releasing activity, tissue kallikrein directly interacts with the kinin B2 receptor, protease-activated receptor-1, and gamma-epithelial Na channel. The tissue kallikrein-kinin system (KKS) elicits a wide spectrum of biological activities, including reducing hypertension, cardiac and renal damage, restenosis, ischemic stroke, and skin wound injury. Both loss-of-function and gain-of-function studies have shown that the KKS plays an important endogenous role in the protection against health pathologies. Tissue kallikrein/kinin treatment attenuates cardiovascular, renal, and brain injury by inhibiting oxidative stress, apoptosis, inflammation, hypertrophy, and fibrosis and promoting angiogenesis and neurogenesis. Approaches that augment tissue kallikrein-kinin activity might provide an effective strategy for the treatment of hypertension and associated organ damage. PMID:25130039

  7. Close-in nosecone configuration and blast damage in point backlight x-ray radiography

    Science.gov (United States)

    Fincke, J. R.; Workman, J. B.; Kryala, G. A.; Walsh, P. J.; Evans, S. C.; Tafoya, D.; Landers, D. J.

    2004-10-01

    Radiography of driven targets using point projection backlighting often requires extensive baffling to mitigate background x rays and physical damage due to target debris. One solution to this problem is a camera configuration that places the nosecone very close to the target such that extraneous light is excluded; however debris and blast damage becomes an issue. A successful close-in (design excludes stray light and survives the radiation flux and blast damage due to debris and late-time target expansion. Estimates of blast loading are compared to experimental observations of damage.

  8. Coccidian infection causes oxidative damage in greenfinches.

    Directory of Open Access Journals (Sweden)

    Tuul Sepp

    Full Text Available The main tenet of immunoecology is that individual variation in immune responsiveness is caused by the costs of immune responses to the hosts. Oxidative damage resulting from the excessive production of reactive oxygen species during immune response is hypothesized to form one of such costs. We tested this hypothesis in experimental coccidian infection model in greenfinches Carduelis chloris. Administration of isosporan coccidians to experimental birds did not affect indices of antioxidant protection (TAC and OXY, plasma triglyceride and carotenoid levels or body mass, indicating that pathological consequences of infection were generally mild. Infected birds had on average 8% higher levels of plasma malondialdehyde (MDA, a toxic end-product of lipid peroxidation than un-infected birds. The birds that had highest MDA levels subsequent to experimental infection experienced the highest decrease in infection intensity. This observation is consistent with the idea that oxidative stress is a causative agent in the control of coccidiosis and supports the concept of oxidative costs of immune responses and parasite resistance. The finding that oxidative damage accompanies even the mild infection with a common parasite highlights the relevance of oxidative stress biology for the immunoecological research.

  9. Mining-induced surface damage and the study of countermeasures

    International Nuclear Information System (INIS)

    Coal constitutes China's major energy resource. The majority of the coal is produced from underground mining operations. Surface subsidence may amount to 80% of the thickness of the seam mined, while the subsided volume is around 60% of the mined volume underground. An area of 20 hectares of land will be affected with each 1 million tons of coal mined, thereby causing severe surface damage. Following a description of the characteristics of surface damages due to underground mining disturbance, this paper elaborates on the damage prediction method, standards applied for evaluating the damages experienced by surface buildings, land reclamation methods in subsided area, measures for reinforcing and protecting buildings in mining-affected areas, and performance of antideformation buildings

  10. Damage thresholds in laser-irradiated optical materials

    Science.gov (United States)

    Guignard, Franck; Autric, Michel L.; Baudinaud, Vincent

    1997-05-01

    An experimental study on the damage induced by laser irradiation on different materials, borosilicate glass, fused silicate, molded and stretched polymethylmethacrylate (PMMA), has been performed. The irradiation source is a 1KL pulsed cold cathode electron gun preionized TEA CO2 laser. Damage mechanisms are controlled by the in-depth absorption of the 10.6 micrometers radiation according to the Beer-Lambert law. PMMA is damaged following a boiling process. Stretched PMMA is fractured first, releasing stresses, then boiled like molded PMMA at a higher energy. BK7 crazed after the irradiation due to thermomechanical stresses, silicate melt and vaporized. Optical damages have been characterized by measuring the contrast transfer function through the irradiated samples.

  11. Creep damage development in welded X20 and P91

    Energy Technology Data Exchange (ETDEWEB)

    Brett, Steve; Holmstrom, Stefan; Hald, John; Borg, Ulrik; Aakjaer Jensen, Soeren; Vulpen, Rijk Van; Degnan, Craig; Vinter Dahl, Kristian; Vilhelmsen, Tommy

    2011-03-15

    The Martensitic steel X20CrMoV121 (hereinafter called X20) and the modified 9Cr1Mo steel (hereinafter called P91) have been used for a number of years in high temperature applications since they posses superior creep strength compared to low alloyed steels. Due to the simple fact that very few failures were observed, almost no knowledge as to the evolution of creep damage in welds were available despite long operation times exceeding well over 100.000 hours. It has been suggested that X20 will develop creep damage in a different manner compared to low alloyed steel, i.e damage initiation should be slow followed by accelerated growth. The research work presented in this report included systematic investigations of the first components of X20, which has developed creep during long-term operation. All of the investigated components showed creep damage evolution similar to low alloy steels

  12. Effect of Cumulative Damage on Rocket Motor Service Life

    Science.gov (United States)

    Gligorijević, Nikola; Živković, Saša; Subotić, Sredoje; Rodić, Vesna; Gligorijević, Ivan

    2015-10-01

    Two series of antihail rocket propellant grains failed only 3 months after production, due to the appearance of cracks in the grain channel. Structural integrity analysis demonstrated sufficient reliability at the beginning of service life. Further analysis showed that under temperature loads, cumulative damage during the short period in field stocks caused the grain failure, despite the established opinion that such failure can become significant only after lengthy storage. A linear cumulative damage law is evaluated by exposing a number of hydroxyl-terminated polybutadiene (HTPB) composite propellant specimens to different but constant stress levels. The analysis showed that cumulative damage must not be overlooked at the design stage. Further, a positive correlation between the propellant cumulative damage law and tensile strength is strongly indicated.

  13. Experimental damage analysis of steels after exploitation loading

    Directory of Open Access Journals (Sweden)

    B. Augustyniak

    2010-06-01

    Full Text Available Development of creep damage at elevated temperatures and structural degradation due to plastic deformation at room temperature were assessed using destructive and non-destructive methods in steels commonly applied in power plants (40HNMA, 13HMF and P91. As destructive methods the standard tension tests were carried out after every kind of prestraining. Subsequently, an evolution of the selected tension parameters was taken into account for damage identification. In order to assess a damage development during the creep and plastic deformation the tests for the steels were interrupted for a range of the selected strain magnitudes. The ultrasonic and magnetic techniques were used as the non-destructive methods for damage evaluation. The experimental programme also contained microscopic observations.

  14. Quantum metrology and its application in biology

    OpenAIRE

    Taylor, Michael A.; Bowen, Warwick P.

    2014-01-01

    Quantum metrology provides a route to overcome practical limits in sensing devices. It holds particular relevance to biology, where sensitivity and resolution constraints restrict applications both in fundamental biophysics and in medicine. Here, we review quantum metrology from this biological context, focusing on optical techniques due to their particular relevance for biological imaging, sensing, and stimulation. Our understanding of quantum mechanics has already enabled important applicat...

  15. Network systems biology for targeted cancer therapies

    Institute of Scientific and Technical Information of China (English)

    Ting-Ting Zhou

    2012-01-01

    The era of targeted cancer therapies has arrived.However,due to the complexity of biological systems,the current progress is far from enough.From biological network modeling to structural/dynamic network analysis,network systems biology provides unique insight into the potential mechanisms underlying the growth and progression of cancer cells.It has also introduced great changes into the research paradigm of cancer-associated drug discovery and drug resistance.

  16. Damage Atlas for Photographic materials

    Directory of Open Access Journals (Sweden)

    Kristel Van Camp

    2010-11-01

    Full Text Available La conservation des documents photographiques peut nécessiter des interventions préventives ou curatives. Ce choix est guidé par leur état de conservation. Une meilleure connaissance des détériorations est donc cruciale. Le répertoire présenté ici essaie de les classifier selon des caractéristiques spécifiques et leur niveau de gravité. Les différents types de dégradation sont illustrés et décrits avec une terminologie précise. L’auteur propose en regard de ceux-ci l’intervention qui semble la plus appropriée. Ce répertoire s’adresse à toutes les personnes concernées par la photographie, qu’ils soient dans le milieu de la conservation ou dans le domaine artistique, dans les musées ou dans les archives. In order to rescue a damaged photographic object, preventive or conservative actions are needed. Knowing the specific characteristics of different types of damage is crucial. A damage atlas can provide these characteristics. With this atlas the damage can be recognised and appropriate actions can be taken. This damage atlas offers a first attempt to such a characterisation in the field of photography. The damage atlas contains images and the necessary information about damage on photographic material. The atlas with special annotations about the terminology and the grade of the damage is meant for everybody who works with photographic material, as well in museums as in archives.

  17. How expensive is vole damage?

    OpenAIRE

    Walther, B; Fülling, O.; Malevez, J.; Pelz, H.-J.

    2008-01-01

    Vole species, especially Arvicola terrestris and Microtus arvalis cause significant economical damage in organic pomiculture by gnawing the root system of trees. The importance of voles as pest organisms is well known. Nevertheless, the estimation of financial loss caused by voles is difficult for German fruit growers. We conducted a survey among organic fruit growers to get data on kind and amount of annual damage. Using the available publications and official statistics we calculated econom...

  18. Nav Channels in Damaged Membranes.

    Science.gov (United States)

    Morris, C E; Joos, B

    2016-01-01

    Sick excitable cells (ie, Nav channel-expressing cells injured by trauma, ischemia, inflammatory, and other conditions) typically exhibit "acquired sodium channelopathies" which, we argue, reflect bleb-damaged membranes rendering their Nav channels "leaky." The situation is excitotoxic because untreated Nav leak exacerbates bleb damage. Fast Nav inactivation (a voltage-independent process) is so tightly coupled, kinetically speaking, to the inherently voltage-dependent process of fast activation that when bleb damage accelerates and thus left-shifts macroscopic fast activation, fast inactivation accelerates to the same extent. The coupled g(V) and availability(V) processes and their window conductance regions consequently left-shift by the same number of millivolts. These damage-induced hyperpolarizing shifts, whose magnitude increases with damage intensity, are called coupled left shift (CLS). Based on past work and modeling, we discuss how to test for Nav-CLS, emphasizing the virtue of sawtooth ramp clamp. We explain that it is the inherent mechanosensitivity of Nav activation that underlies Nav-CLS. Using modeling of excitability, we show the known process of Nav-CLS is sufficient to predict a wide variety of "sick excitable cell" phenomena, from hyperexcitability through to depolarizing block. When living cells are mimicked by inclusion of pumps, mild Nav-CLS produces a wide array of burst phenomena and subthreshold oscillations. Dynamical analysis of mild damage scenarios shows how these phenomena reflect changes in spike thresholds as the pumps try to counteract the leaky Nav channels. Smart Nav inhibitors designed for sick excitable cells would target bleb-damaged membrane, buying time for cell-mediated removal or repair of Nav-bearing membrane that has become bleb-damaged (ie, detached from the cytoskeleton). PMID:27586295

  19. A high sensitivity, high throughput, automated single-cell gel electrophoresis ('Comet') DNA damage assay

    International Nuclear Information System (INIS)

    A fully automated microscopy machine vision image capture and analysis system for the collection of data from slides of 'comets' has been developed. The novel image processing algorithms employed in delineating the 'comet head' from the 'comet tail' allow us to determine accurately very low levels of damage. In conjunction with calibrated and automated image capture methods, we are able to eliminate operator subjectivity and analyse large numbers of cells (>2500) in a short time (<1 hour). The image processing algorithm is designed to handle particularly difficult nuclei containing a high degree of structure, due to DNA clumping. We also present techniques used to extend the assay's dynamic range by removing interfering background fluorescence and to define a region of interest. If subtle biological variations are to be quantified (e.g. cell cycle dependant damage), then the use of large cell populations is dictated. Under those circumstances, the use of a fully automated system is particularly advantageous providing that the manner in which data is extracted does not introduce any inadvertent bias. In practice, it is essential that the image processing steps are geared towards the correct recognition of an acceptable cell nucleus, i.e. comet 'head'. We acknowledge the financial support of CRUK, Programme Grant C133/A1812 - SP 2195-01/02 and the US Department of Energy Low Dose Radiation Research Program grant DE-FG07-99ER62878

  20. Bactericidal activity of curcumin I is associated with damaging of bacterial membrane.

    Directory of Open Access Journals (Sweden)

    Poonam Tyagi

    Full Text Available Curcumin, an important constituent of turmeric, is known for various biological activities, primarily due to its antioxidant mechanism. The present study focused on the antibacterial activity of curcumin I, a significant component of commercial curcumin, against four genera of bacteria, including those that are Gram-positive (Staphylococcus aureus and Enterococcus faecalis and Gram-negative (Escherichia coli and Pseudomonas aeruginosa. These represent prominent human pathogens, particularly in hospital settings. Our study shows the strong antibacterial potential of curcumin I against all the tested bacteria from Gram-positive as well as Gram-negative groups. The integrity of the bacterial membrane was checked using two differential permeabilization indicating fluorescent probes, namely, propidium iodide and calcein. Both the membrane permeabilization assays confirmed membrane leakage in Gram-negative and Gram-positive bacteria on exposure to curcumin I. In addition, scanning electron microscopy and fluorescence microscopy were employed to confirm the membrane damages in bacterial cells on exposure to curcumin I. The present study confirms the broad-spectrum antibacterial nature of curcumin I, and its membrane damaging property. Findings from this study could provide impetus for further research on curcumin I regarding its antibiotic potential against rapidly emerging bacterial pathogens.

  1. A Review on Radiation Damage in Concrete for Nuclear Facilities: From Experiments to Modeling

    Directory of Open Access Journals (Sweden)

    Beatrice Pomaro

    2016-01-01

    Full Text Available Concrete is a relatively cheap material and easy to be cast into variously shaped structures. Its good shielding properties against neutrons and gamma-rays, due to its intrinsic water content and relatively high-density, respectively, make it the most widely used material for radiation shielding also. Concrete is so chosen as biological barrier in nuclear reactors and other nuclear facilities where neutron sources are hosted. Theoretical formulas are available in nuclear engineering manuals for the optimum thickness of shielding for radioprotection purposes; however they are restricted to one-dimensional problems; besides the basic empirical constants do not consider radiation damage effects, while its long-term performance is crucial for the safe operation of such facilities. To understand the behaviour of concrete properties, it is necessary to examine concrete strength and stiffness, water behavior, volume change of cement paste, and aggregate under irradiated conditions. Radiation damage process is not well understood yet and there is not a unified approach to the practical and predictive assessment of irradiated concrete, which combines both physics and structural mechanics issues. This paper provides a collection of the most distinguished contributions on this topic in the past 50 years. At present a remarkable renewed interest in the subject is shown.

  2. Cranberry flavonoids prevent toxic rat liver mitochondrial damage in vivo and scavenge free radicals in vitro.

    Science.gov (United States)

    Lapshina, Elena A; Zamaraeva, Maria; Cheshchevik, Vitali T; Olchowik-Grabarek, Ewa; Sekowski, Szymon; Zukowska, Izabela; Golovach, Nina G; Burd, Vasili N; Zavodnik, Ilya B

    2015-06-01

    The present study was undertaken for further elucidation of the mechanisms of flavonoid biological activity, focusing on the antioxidative and protective effects of cranberry flavonoids in free radical-generating systems and those on mitochondrial ultrastructure during carbon tetrachloride-induced rat intoxication. Treatment of rats with cranberry flavonoids (7 mg/kg) during chronic carbon tetrachloride-induced intoxication led to prevention of mitochondrial damage, including fragmentation, rupture and local loss of the outer mitochondrial membrane. In radical-generating systems, cranberry flavonoids effectively scavenged nitric oxide (IC50  = 4.4 ± 0.4 µg/ml), superoxide anion radicals (IC50  = 2.8 ± 0.3 µg/ml) and hydroxyl radicals (IC50  = 53 ± 4 µg/ml). The IC50 for reduction of 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH) was 2.2 ± 0.3 µg/ml. Flavonoids prevented to some extent lipid peroxidation in liposomal membranes and glutathione oxidation in erythrocytes treated with UV irradiation or organic hydroperoxides as well as decreased the rigidity of the outer leaflet of the liposomal membranes. The hepatoprotective potential of cranberry flavonoids could be due to specific prevention of rat liver mitochondrial damage. The mitochondria-addressed effects of flavonoids might be related both to radical-scavenging properties and modulation of various mitochondrial events.

  3. Immunochemical approach to the study of DNA damage and repair. Technical progress report

    International Nuclear Information System (INIS)

    We are studying damages that have been shown to be stable radiolysis products found in x-irradiation DNA and thus products that have potential biological consequences. Four thymine ring saturation or fragmentation products were chosen as models for pyrimidine radiolysis products. The first product we synthesized and to which antibodies were elicited was thymine glycol. Thymine glycols are the major stable radiolysis products produced in DNA x-radiation in vitro. Although they retain base pairing characteristics, the stacking properties of thymine glycols are altered due to the saturation of the 5.6 double bond. Thymine glucol is also a useful model because alternative assay proceudres are available and they can selectively be produced in DNA by osmium tetroxide oxidation allowing the development of standards for subsequent measurement of DNA damage in x-irradiated DNA. We have also raised antibodies to dihydrothymine, a major radiolysis product produced in NDA under anaerobic conditions, to 5-hydroxy-5-methylhydantoin, the second most predominant stable radiolysis product producted under aerobic conditions, and to urea, a totally non-instructive DNA fragmentation product of thymine hydroperoxides. 29 refs., 2 figs

  4. [Dementia due to Endocrine Diseases].

    Science.gov (United States)

    Matsunaga, Akiko; Yoneda, Makoto

    2016-04-01

    Endocrine diseases affecting various organs, such as the pituitary gland, the thyroid, the parathyroid, the adrenal glands and the pancreas, occasionally cause dementia. While Alzheimer's disease (AD) is the main cause of dementia in the elderly and is untreatable, dementia caused by endocrine diseases is treatable in most cases. However, patients with dementia associated with endocrine diseases show memory impairments similar to those found in AD, often leading to misdiagnoses. Patients with endocrine diseases often present with other characteristic systemic and neuropsychiatric symptoms caused by altered hormone levels. Such neuropsychiatric symptoms include involuntary movements, depression, seizures, and muscle weakness. In these cases, abnormalities in imaging and blood or urine tests are helpful in making a differential diagnosis. As delays in the diagnosis and treatment of these patients may cause irreversible brain damage, it is imperative for clinicians to carefully exclude the possibility of latent endocrine diseases when treating patients with dementia.

  5. Mechanism of DNA damage tolerance

    Institute of Scientific and Technical Information of China (English)

    Xin; Bi

    2015-01-01

    DNA damage may compromise genome integrity and lead to cell death. Cells have evolved a variety of processes to respond to DNA damage including damage repair and tolerance mechanisms, as well as damage checkpoints. The DNA damage tolerance(DDT) pathway promotes the bypass of single-stranded DNA lesions encountered by DNA polymerases during DNA replication. This prevents the stalling of DNA replication. Two mechanistically distinct DDT branches have been characterized. One is translesion synthesis(TLS) in which a replicative DNA polymerase is temporarily replaced by a specialized TLS polymerase that has the ability to replicate across DNA lesions. TLS is mechanistically simple and straightforward, but it is intrinsically error-prone. The other is the error-free template switching(TS) mechanism in which the stalled nascent strand switches from the damaged template to the undamaged newly synthesized sister strand for extension past the lesion. Error-free TS is a complex but preferable process for bypassing DNA lesions. However, our current understanding of this pathway is sketchy. An increasing number of factors are being found to participate or regulate this important mechanism, which is the focus of this editorial.

  6. Advances in Fish Biology in Ireland

    OpenAIRE

    Moriarty, C.

    1983-01-01

    Due to little information exchange between Irish freshwater biologists, a seminar was was held to help broaden and share the knowledge of those participating in professional or amateur freshwater biology in Ireland.

  7. Biological effects of radiation

    International Nuclear Information System (INIS)

    This fourth chapter presents: cell structure and metabolism; radiation interaction with biological tissues; steps of the production of biological effect of radiation; radiosensitivity of tissues; classification of biological effects; reversibility, transmissivity and influence factors; pre-natal biological effects; biological effects in therapy and syndrome of acute irradiation

  8. Signaling in the induction of genomic damage by endogenous compounds

    OpenAIRE

    Fazeli, Gholamreza

    2011-01-01

    Reactive oxygen species (ROS) are continuously generated in cells and are involved in physiological processes including signal transduction but also their damaging effects on biological molecules have been well described. A number of reports in the literature implicate excessive oxidative stress and/or inadequate antioxidant defense in the pathogenesis of cancer, atherosclerosis, chronic and age related disorders. Several studies have indicated that activation of the renin-angiotensin-aldoste...

  9. Nucleotide Salvage Deficiencies, DNA Damage and Neurodegeneration

    Directory of Open Access Journals (Sweden)

    Michael Fasullo

    2015-04-01

    Full Text Available Nucleotide balance is critically important not only in replicating cells but also in quiescent cells. This is especially true in the nervous system, where there is a high demand for adenosine triphosphate (ATP produced from mitochondria. Mitochondria are particularly prone to oxidative stress-associated DNA damage because nucleotide imbalance can lead to mitochondrial depletion due to low replication fidelity. Failure to maintain nucleotide balance due to genetic defects can result in infantile death; however there is great variability in clinical presentation for particular diseases. This review compares genetic diseases that result from defects in specific nucleotide salvage enzymes and a signaling kinase that activates nucleotide salvage after DNA damage exposure. These diseases include Lesch-Nyhan syndrome, mitochondrial depletion syndromes, and ataxia telangiectasia. Although treatment options are available to palliate symptoms of these diseases, there is no cure. The conclusions drawn from this review include the critical role of guanine nucleotides in preventing neurodegeneration, the limitations of animals as disease models, and the need to further understand nucleotide imbalances in treatment regimens. Such knowledge will hopefully guide future studies into clinical therapies for genetic diseases.

  10. Repair of DNA damage induced by ultraviolet radiation

    International Nuclear Information System (INIS)

    Studies documenting the depletion of the ozone layer and the resulting increases in UV-B radiation (280-320 nm) at the Earth's surface have served to focus attention on the biological effects of UV light. One obvious target for UVB- induced damage is DNA. Although a11 biological tissues are rich in UV-absorbing agents (largely nucleic acids and proteins) and plants produce additional UV-absorbing pigments, no DNA in superficial tissue can completely avoid UV exposure. Plants, like a11 living organisms, must have some capacity for the repair of UV-induced DNA damage. Because plants are unique in the obligatory nature of their exposure to UV, it is also conceivable that they may have evolved particularly efficient mechanisms for the elimination of UV-induced DNA damage. This review will summarize what we know about DNA repair mechanisms in higher plants. Readers interested in broader aspects of UV-induced damage and UV filters are directed to recent reviews (Middleton and Teramura, 1994; Strid et al., 1994; Fiscus and Booker, 1995). Our knowledge of DNA repair mechanisms in plants lags far behind our understanding of these pathways in animals, and a significant number of questions concerning the basic phenomenology of DNA repair in plants remain to be addressed

  11. Macro-residual strains due to cyclic loading of composites

    CERN Document Server

    Hashin, Z

    1999-01-01

    Macro-residual strains produced by load cycles on elastic-brittle composites are analytically expressed in terms of the effective thermal expansion coefficients of the composite as affected by the damage states developing during the $9 cycling. Limiting values of residual strain are evaluated for unidirectional fiber composites and cross-ply laminates. Frictional losses due to internal sliding are not considered. (17 refs).

  12. DNA damage and repair mechanism. [DNA damage and repair mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Grossman, L.

    1976-01-01

    The ability of cells to survive in an environment specifically damaging to its DNA can be attributed to a variety of inherent repair mechanisms. This is a form of repair in which alterations are directly reversed to their original form. This reversibility is exemplified by the photoreactivation of ultraviolet-induced pyrimidine dimers. This phenomenon is attributable to the action of an enzyme, photolyase (photoreactivating enzyme), which is able to monomerize the uv-induced pyrimidine dimers in the presence of 320 to 370 nm light. Dilution of damage can be effected through a series of sister chromatid exchanges, controlled by recombinational mechanisms as a postreplication event. In this form of repair, replication proceeds to the point of damage, stops and resumes at the point of the next initiation site resulting in a gap in the newly synthesized daughter strand. It is presumed that those strands containing damaged regions exchange with undamaged regions of other DNA, strands, resulting in the eventual dilution of such damage.

  13. Neurocomputational models of the remote effects of focal brain damage.

    Science.gov (United States)

    Reggia, James A

    2004-11-01

    Sudden localized brain damage, such as occurs in stroke, produces neurological deficits directly attributable to the damaged site. In addition, other clinical deficits occur due to secondary "remote" effects that functionally impair the remaining intact brain regions (e.g., due to their sudden disconnection from the damaged area), a phenomenon known as diaschisis. The underlying mechanisms of these remote effects, particularly those involving interactions between the left and right cerebral hemispheres, have proven somewhat difficult to understand in the context of current theories of hemispheric specialization. This article describes some recent neurocomputational models done in the author's research group that try to explain diaschisis qualitatively. These studies show that both specialization and diaschisis can be accounted for with a single model of hemispheric interactions. Further, the results suggest that left-right subcortical influences may be much more important in influencing hemispheric specialization than is generally recognized. PMID:15564108

  14. Thermal recovery of bitumen from carbonate reservoirs: formation damage aspects

    Energy Technology Data Exchange (ETDEWEB)

    Thimm, H.F. [Thimm Petroleum Technologies Inc. (Canada)

    2011-07-01

    In Alberta, about a third of bitumen resources are located in carbonate reservoirs but none of it is considered as a reserve by the Alberta Energy Resources Conservation Board (ERCB). In fact no pilot has been successful in recovering bitumen from carbonate reservoirs due to formation damage problems. Carbonate rock is chemically active at the high temperatures reached in thermal recovery processes, carbon dioxide is generated and carbonate minerals are precipitated. The aim of this paper is to find methods to control the phenomenon. Kinetic and thermodynamic controls were used. Results showed that formation damage is due to aqueous carbon dioxide attacking the reservoir rock. They found that a reduction of the partial pressure of carbon dioxide could inhibit the initial dissolution of rock material by reducing the concentration of aqueous carbon dioxide. A method to overcome the formation damage problem was found and a co-injection of gas and steam process was developed to apply it.

  15. Stroke due to Hematologic Aspects

    Institute of Scientific and Technical Information of China (English)

    刘泽霖

    2004-01-01

    @@ Stroke due to ‘cerebral vein thrombosis' (CVT) is commonly used to refer to thrombosis of the cerebral venous system, including either dural venous sinuses, or deep and superficial (cortical) cerebral veins. CVT are frightening events due to the severity of their clinical manifestations and their high mortality rate (up to 30% in some casereports).The clinical signs and symptoms of CVT are relatively nonspecific: they include headache, papilledema, vomiting,seizures, focal neurological deficits (motor or sensory) and impaired consciousness. CVT has long been considered as rare and mostly infection-related event; moreover, due to its nonspecific clinical manifestations, the diagnosis has been difficult, delayed and could often be made only post mortem.

  16. Guarding chromosomes from oxidative DNA damage to the very end

    Institute of Scientific and Technical Information of China (English)

    Rong Tan; Li Lan

    2016-01-01

    The ends of each chromosome are capped by the telomere assembly to protect chromosomal integrity from telomere attrition and DNA damage.In response to DNA damage,DNA repair factors are enriched at damage sites by a sophisticated signaling and recruitment cascade.However,DNA damage response at telomeres is different from non-telomeric region of genomic DNA due to specialized sequences and structures of the telomeres.In the course of normal DNA replication or DNA damage repair,both the telomere shelterin protein complex and the condensed telomeric chromatin structure in mammalian cells are modified to protect telomeres from exposing free DNA ends which are subject to both telemere shortening and chromosome end fusion.Initiation of either homologous recombination or non-homologous end joint repair at telomeres requires disassembling andaor post-translational modifications of the shelterin complex and telomeric chromatin.In addition,cancer cells utilize distinct mechanisms to maintain telomere length and cell survival upon damage.In this review,we summarize current studies that focus on telomere end protection and telomere DNA repair using different methodologies to model telomere DNA damage and disruption.These include genetic ablation of sheltering proteins,targeting endonuclease to telomeres,and delivering oxidative damage directly.These different approaches,when combined,offer better understanding of the mechanistic differences in DNA damage response between telomeric and genomic DNA,which will provide new hope to identify potential cancer therapeutic targets to curtail cancer cell proliferation via induction of telomere dysfunctions.

  17. Detection of DNA damage by using hairpin molecular beacon probes and graphene oxide.

    Science.gov (United States)

    Zhou, Jie; Lu, Qian; Tong, Ying; Wei, Wei; Liu, Songqin

    2012-09-15

    A hairpin molecular beacon tagged with carboxyfluorescein in combination with graphene oxide as a quencher reagent was used to detect the DNA damage by chemical reagents. The fluorescence of molecular beacon was quenched sharply by graphene oxide; while in the presence of its complementary DNA the quenching efficiency decreased because their hybridization prevented the strong adsorbability of molecular beacon on graphene oxide. If the complementary DNA was damaged by a chemical reagent and could not form intact duplex structure with molecular beacon, more molecular beacon would adsorb on graphene oxide increasing the quenching efficiency. Thus, damaged DNA could be detected based on different quenching efficiencies afforded by damaged and intact complementary DNA. The damage effects of chlorpyrifos-methyl and three metabolites of styrene such as mandelieaeids, phenylglyoxylieaeids and epoxystyrene on DNA were studied as models. The method for detection of DNA damage was reliable, rapid and simple compared to the biological methods.

  18. Heart failure after aortic valve substitution due to severe hypothyroidism

    DEFF Research Database (Denmark)

    Munk, Kim; Sørensen, Stine Heidenheim; Andersen, Niels Holmark;

    2008-01-01

    We report a case of a 70-year-old female with considerable co-morbidities (Type 2 diabetes, Leiden factor V mutation, mild to moderate chronic obstructive pulmonary disease) and a recent biological aortic valve substitution, who was admitted due to circulatory collapse caused by severe heart fail...

  19. Biological consequences of nuclear war

    International Nuclear Information System (INIS)

    Irradiation probability due to radionuclide fallout is shown to exceed 1 Gy even for the territories which have not been affected by nuclear weapons direct explosions. If some people survive in the nuclear war, their heredity would be affected. Genetic consequences of nuclear war complete the process of Homo sapiens disappearance from the Earth. Space weapons development will deteriorate the prospects of civilization ruin as a result of biological aftereffects of nuclear war and possible application of new arms, as well as chemical and biologic weapons

  20. Salt crystallization damage: how realistic are existing ageing tests

    NARCIS (Netherlands)

    Lubelli, B.A.; Hees, R.P.J. van; Nijland, T.G.

    2014-01-01

    Salt crystallization is a major cause of damage in porous building materials (figure l). Notwithstanding the extensive research in this held, the complexity of the problem has hindered the use of mathematical models for forecasting ageing due to salt crystallization. Nowadays, the resistance of mate

  1. 3'-Phosphoadenosine 5'-phosphosulfate synthase 1 (PAPSS1) knockdown sensitizes non-small cell lung cancer cells to DNA damaging agents.

    Science.gov (United States)

    Leung, Ada W Y; Dragowska, Wieslawa H; Ricaurte, Daniel; Kwok, Brian; Mathew, Veena; Roosendaal, Jeroen; Ahluwalia, Amith; Warburton, Corinna; Laskin, Janessa J; Stirling, Peter C; Qadir, Mohammed A; Bally, Marcel B

    2015-07-10

    Standard treatment for advanced non-small cell lung cancer (NSCLC) with no known driver mutation is platinum-based chemotherapy, which has a response rate of only 30-33%. Through an siRNA screen, 3'-phosphoadenosine 5'-phosphosulfate (PAPS) synthase 1 (PAPSS1), an enzyme that synthesizes the biologically active form of sulfate PAPS, was identified as a novel platinum-sensitizing target in NSCLC cells. PAPSS1 knockdown in combination with low-dose (IC10) cisplatin reduces clonogenicity of NSCLC cells by 98.7% (p < 0.001), increases DNA damage, and induces G1/S phase cell cycle arrest and apoptosis. PAPSS1 silencing also sensitized NSCLC cells to other DNA crosslinking agents, radiation, and topoisomerase I inhibitors, but not topoisomerase II inhibitors. Chemo-sensitization was not observed in normal epithelial cells. Knocking out the PAPSS1 homolog did not sensitize yeast to cisplatin, suggesting that sulfate bioavailability for amino acid synthesis is not the cause of sensitization to DNA damaging agents. Rather, sensitization may be due to sulfation reactions involved in blocking the action of DNA damaging agents, facilitating DNA repair, promoting cancer cell survival under therapeutic stress or reducing the bioavailability of DNA damaging agents. Our study demonstrates for the first time that PAPSS1 could be targeted to improve the activity of multiple anticancer agents used to treat NSCLC. PMID:26220590

  2. 3′-Phosphoadenosine 5′-phosphosulfate synthase 1 (PAPSS1) knockdown sensitizes non-small cell lung cancer cells to DNA damaging agents

    Science.gov (United States)

    Leung, Ada W. Y.; Dragowska, Wieslawa H.; Ricaurte, Daniel; Kwok, Brian; Mathew, Veena; Roosendaal, Jeroen; Ahluwalia, Amith; Warburton, Corinna; Laskin, Janessa J.; Stirling, Peter C.; Qadir, Mohammed A.; Bally, Marcel B.

    2015-01-01

    Standard treatment for advanced non-small cell lung cancer (NSCLC) with no known driver mutation is platinum-based chemotherapy, which has a response rate of only 30–33%. Through an siRNA screen, 3′-phosphoadenosine 5′-phosphosulfate (PAPS) synthase 1 (PAPSS1), an enzyme that synthesizes the biologically active form of sulfate PAPS, was identified as a novel platinum-sensitizing target in NSCLC cells. PAPSS1 knockdown in combination with low-dose (IC10) cisplatin reduces clonogenicity of NSCLC cells by 98.7% (p < 0.001), increases DNA damage, and induces G1/S phase cell cycle arrest and apoptosis. PAPSS1 silencing also sensitized NSCLC cells to other DNA crosslinking agents, radiation, and topoisomerase I inhibitors, but not topoisomerase II inhibitors. Chemo-sensitization was not observed in normal epithelial cells. Knocking out the PAPSS1 homolog did not sensitize yeast to cisplatin, suggesting that sulfate bioavailability for amino acid synthesis is not the cause of sensitization to DNA damaging agents. Rather, sensitization may be due to sulfation reactions involved in blocking the action of DNA damaging agents, facilitating DNA repair, promoting cancer cell survival under therapeutic stress or reducing the bioavailability of DNA damaging agents. Our study demonstrates for the first time that PAPSS1 could be targeted to improve the activity of multiple anticancer agents used to treat NSCLC. PMID:26220590

  3. Perception of biological motion in visual agnosia

    Directory of Open Access Journals (Sweden)

    Elisabeth eHuberle

    2012-08-01

    Full Text Available Over the past twenty-five years, visual processing has been discussed in the context of the dual stream hypothesis consisting of a ventral (‘what' and a dorsal ('where' visual information processing pathway. Patients with brain damage of the ventral pathway typically present with signs of visual agnosia, the inability to identify and discriminate objects by visual exploration, but show normal perception of motion perception. A dissociation between the perception of biological motion and non-biological motion has been suggested: Perception of biological motion might be impaired when 'non-biological' motion perception is intact and vice versa. The impact of object recognition on the perception of biological motion remains unclear. We thus investigated this question in a patient with severe visual agnosia, who showed normal perception of non-biological motion. The data suggested that the patient's perception of biological motion remained largely intact. However, when tested with objects constructed of coherently moving dots (‘Shape-from-Motion’, recognition was severely impaired. The results are discussed in the context of possible mechanisms of biological motion perception.

  4. Perception of biological motion in visual agnosia.

    Science.gov (United States)

    Huberle, Elisabeth; Rupek, Paul; Lappe, Markus; Karnath, Hans-Otto

    2012-01-01

    Over the past 25 years, visual processing has been discussed in the context of the dual stream hypothesis consisting of a ventral ("what") and a dorsal ("where") visual information processing pathway. Patients with brain damage of the ventral pathway typically present with signs of visual agnosia, the inability to identify and discriminate objects by visual exploration, but show normal perception of motion perception. A dissociation between the perception of biological motion and non-biological motion has been suggested: perception of biological motion might be impaired when "non-biological" motion perception is intact and vice versa. The impact of object recognition on the perception of biological motion remains unclear. We thus investigated this question in a patient with severe visual agnosia, who showed normal perception of non-biological motion. The data suggested that the patient's perception of biological motion remained largely intact. However, when tested with objects constructed of coherently moving dots ("Shape-from-Motion"), recognition was severely impaired. The results are discussed in the context of possible mechanisms of biological motion perception.

  5. Climate change damage functions in LCA – (1) from global warming potential to natural environment damages

    DEFF Research Database (Denmark)

    Callesen, Ingeborg; Hauschild, Michael Zwicky; Bagger Jørgensen, Rikke;

    methodology. The current scientific understanding of the extent of climate change impacts is limited due to the immense complexity of the multi-factorial environmental changes and unknown adaptive capacities at process, species and ecosystem level. In the presentation we argue that the global warming impacts...... from a product system being studied in an LCA must be seen in context with the changing future background situation. This background situation is among other things affected by e.g. cumulative atmospheric greenhouse gas emissions of yet unknown magnitude. Here, we define climate change damage...... on the natural environment as climate change driven environmental changes. The man-made environment such as cultivated land, infrastructure and urban areas is not considered. Hypothetical climate change damage functions representing both sensitive and robust responses were analyzed in relation to cumulative...

  6. Valuations of social costs due to electricity production

    International Nuclear Information System (INIS)

    This article describes the valuations of social costs due to the electricity production in Germany, United States and Italy. First, social costs are defined and the most frequently used methods to quantify them are described, then the application of these methods is shown together with the figures obtained in the above mentioned countries. Presently the assessments of social costs are understimated because many externalities, here listed, have not been taken into account either for methodological difficulties or for lack of data: however the assessments of the damages caused by the several polluting agents are quite consistent except with respect to the greenhouse effect due to CO2 emissions

  7. Traumatic pseudocyst due to blunt trauma: Case report.

    Science.gov (United States)

    Becel, Sinan; Oztok, Beliz; Kurtoglu Celik, Gulhan; Icme, Ferhat; Sener, Alp; Pamukcu Gunaydin, Gul

    2015-09-01

    Damage to lung parenchyma due to blunt thoracic trauma often appears as contusion or hematoma. Cavitary lung lesions or pseudocyst formation due to trauma is a rare phenomenon. In the literature traumatic pseudocysts are also known as pseudocystic hematomas, traumatic lung cavity and traumatic pneumotocel. Traumatic pseudocysts usually have good clinical prognosis, recover spontaneously with supportive treatment and do not require surgery. In this article, we present the case of 52 year old male who was brought to the emergency department after a fall from height and was diagnosed with lung contusions and traumatic cyst. PMID:27239612

  8. Endocarditis Due to Citrobacter Freundii

    OpenAIRE

    Reyes, Cesar V.; Folwarkiw, Oksana

    1984-01-01

    The etiologic association of acute bacterial endocarditis with the Citrobacter species has been rare, although it is one of the opportunistic organisms that afflicts the elderly, neonates, the debilitated and immunocompromised. We report a case of endocarditis due to Citrobacter freundii.

  9. Effect of biologic agents on radiographic progression of rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Gabriel J Tobón

    2010-08-01

    Full Text Available Gabriel J Tobón1, Alain Saraux1,2, Valérie Devauchelle-Pensec1,21Immunology Laboratory, Morvan Hospital, Université de Bretagne Occidentale, Brest, France; 2Rheumatology Unit, Hôpital de la Cavale Blanche, CHU Brest, FranceAbstract: The treatment of rheumatoid arthritis (RA has benefited over the last few years from the introduction of biologic agents whose development was based on new insights into the immunological factors involved in the pathogenesis of RA and the development of joint damage. These biological agents have been proven effective in RA patients with inadequate responses to synthetic disease-modifying antirheumatic drugs (DMARDs. Preventing joint damage is now the primary goal of RA treatment, and guidelines exist for the follow-up of joint abnormalities. Most biologic agents produced high clinical and radiological response rates in patients with established or recent-onset RA. Thus, for the first time, obtaining a remission is a reasonable treatment goal in RA patients. Factors that are crucial to joint damage control are: early initiation of DMARDs, use of intensive treatments including biological agents, and close monitoring of clinical disease activity and radiographic progression. However, some patients remain unresponsive to all available treatments and continue to experience joint damage progression. A major objective now is to identify patients at high risk for severe joint damage, in order to tailor the treatment regimen to their specific needs.Keywords: rheumatoid arthritis, radiographic progression, biologics

  10. Autophagy in DNA Damage Response

    Directory of Open Access Journals (Sweden)

    Piotr Czarny

    2015-01-01

    Full Text Available DNA damage response (DDR involves DNA repair, cell cycle regulation and apoptosis, but autophagy is also suggested to play a role in DDR. Autophagy can be activated in response to DNA-damaging agents, but the exact mechanism underlying this activation is not fully understood, although it is suggested that it involves the inhibition of mammalian target of rapamycin complex 1 (mTORC1. mTORC1 represses autophagy via phosphorylation of the ULK1/2–Atg13–FIP200 complex thus preventing maturation of pre-autophagosomal structures. When DNA damage occurs, it is recognized by some proteins or their complexes, such as poly(ADPribose polymerase 1 (PARP-1, Mre11–Rad50–Nbs1 (MRN complex or FOXO3, which activate repressors of mTORC1. SQSTM1/p62 is one of the proteins whose levels are regulated via autophagic degradation. Inhibition of autophagy by knockout of FIP200 results in upregulation of SQSTM1/p62, enhanced DNA damage and less efficient damage repair. Mitophagy, one form of autophagy involved in the selective degradation of mitochondria, may also play role in DDR. It degrades abnormal mitochondria and can either repress or activate apoptosis, but the exact mechanism remains unknown. There is a need to clarify the role of autophagy in DDR, as this process may possess several important biomedical applications, involving also cancer therapy.

  11. Vitamin C for stabilising biological lasers (Conference Presentation)

    Science.gov (United States)

    Kar, Ajoy K.; Mackenzie, Mark D.; Cialowicz, Katarzyna I.; Saleeb, Rebecca S.; Duncan, Rory R.

    2016-04-01

    We report on efforts to improve the lifetime of biological lasers through the use of ascorbic acid (also commonly known as vitamin C). Fluorescent proteins and dyes, used in biological lasers, suffer from photobleaching due to the build-up of reactive oxygen species (ROS) which causes damage leading to a decrease in emission over time. This is an issue both for laser lifetime and cell health. It has previously been shown that ascorbic acid can be effective in reducing ROS levels in a variety of applications. For our experiments human embryonic kidney cells (HEK293), containing the fluorescent dye Calcein AM, were placed between two dielectric plane mirrors to form a laser cavity. The cells were pumped using the output of a Ti:Sapphire femtosecond OPO system, frequency doubled twice in BBO crystals, giving an output of 474 nm. Initial results have shown an increase in laser lifetime when ascorbic acid is added to cells indicating a reduction in the build-up of ROS.

  12. Statistical model for economic damage from pluvial floods in Japan using rainfall data and socioeconomic parameters

    Science.gov (United States)

    Bhattarai, Rajan; Yoshimura, Kei; Seto, Shinta; Nakamura, Shinichiro; Oki, Taikan

    2016-05-01

    The assessment of flood risk is important for policymakers to evaluate damage and for disaster preparation. Large population densities and high property concentration make cities more vulnerable to floods and having higher absolute damage per year. A number of major cities in the world suffer from flood inundation damage every year. In Japan, approximately USD 1 billion in damage occurs annually due to pluvial floods only. The amount of damage was typically large in large cities, but regions with lower population density tended to have more damage per capita. Our statistical approach gives the probability of damage following every daily rainfall event and thereby the annual damage as a function of rainfall, population density, topographical slope and gross domestic product. Our results for Japan show reasonable agreement with area-averaged annual damage for the period 1993-2009. We report a damage occurrence probability function and a damage cost function for pluvial flood damage, which makes this method flexible for use in future scenarios and also capable of being expanded to different regions.

  13. Treatment of oral mucositis due to chemotherapy

    Science.gov (United States)

    Bagán-Sebastián, José V

    2016-01-01

    Introduction The management of oral mucositis is a challenge, due to its complex biological nature. Over the last 10 years, different strategies have been developed for the management of oral mucositis caused by chemotherapy in cancer patients. Material and Methods An exhaustive search was made of the PubMed-Medline, Cochrane Library and Scopus databases, crossing the key words “oral mucositis”, “prevention” and “treatment” with the terms “chemotherapy” and “radiotherapy” by means of the boolean operators “AND” and “NOT”. A total of 268 articles were obtained, of which 96 met the inclusion criteria. Results Several interventions for the prevention of oral mucositis, such as oral hygiene protocols, amifostine, benzidamine, calcium phosphate, cryotherapy and iseganan, among others, were found to yield only limited benefits. Other studies have reported a decrease in the appearance and severity of mucositis with the use of cytoprotectors (sucralfate, oral glutamine, hyaluronic acid), growth factors, topical polyvinylpyrrolidone, and low power laser irradiation. Conclusions Very few interventions of confirmed efficacy are available for the management of oral mucositis due to chemotherapy. However, according to the reviewed literature, the use of palifermin, cryotherapy and low power laser offers benefits, reducing the incidence and severity of oral mucositis – though further studies are needed to confirm the results obtained. Key words:Chemotherapy-Induced Oral Mucositis Treatment. PMID:27034762

  14. Neutron structural biology

    Energy Technology Data Exchange (ETDEWEB)

    Niimura, Nobuo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    Neutron diffraction provides an experimental method of directly locating hydrogen atoms in protein which play important roles in physiological functions. However, there are relatively few examples of neutron crystallography in biology since it takes a lot of time to collect a sufficient number of Bragg reflections due to the low flux of neutrons illuminating the sample. In order to overcome the flux problem, we have successfully developed the neutron IP, where the neutron converter, {sup 6}Li or Gd, was mixed with a photostimulated luminescence material on flexible plastic support. Neutron Laue diffraction 2A data from tetragonal lysozyme were collected for 10 days with neutron imaging plates, and 960 hydrogen atoms in the molecule and 157 bound water molecules were identified. These results explain the proposed hydrolysis mechanism of the sugar by the lysozyme molecule and that lysozyme is less active at pH7.0. (author)

  15. The molecular biology of cancer.

    Science.gov (United States)

    Bertram, J S

    2000-12-01

    The process by which normal cells become progressively transformed to malignancy is now known to require the sequential acquisition of mutations which arise as a consequence of damage to the genome. This damage can be the result of endogenous processes such as errors in replication of DNA, the intrinsic chemical instability of certain DNA bases or from attack by free radicals generated during metabolism. DNA damage can also result from interactions with exogenous agents such as ionizing radiation, UV radiation and chemical carcinogens. Cells have evolved means to repair such damage, but for various reasons errors occur and permanent changes in the genome, mutations, are introduced. Some inactivating mutations occur in genes responsible for maintaining genomic integrity facilitating the acquisition of additional mutations. This review seeks first to identify sources of mutational damage so as to identify the basic causes of human cancer. Through an understanding of cause, prevention may be possible. The evolution of the normal cell to a malignant one involves processes by which genes involved in normal homeostatic mechanisms that control proliferation and cell death suffer mutational damage which results in the activation of genes stimulating proliferation or protection against cell death, the oncogenes, and the inactivation of genes which would normally inhibit proliferation, the tumor suppressor genes. Finally, having overcome normal controls on cell birth and cell death, an aspiring cancer cell faces two new challenges: it must overcome replicative senescence and become immortal and it must obtain adequate supplies of nutrients and oxygen to maintain this high rate of proliferation. This review examines the process of the sequential acquisition of mutations from the prospective of Darwinian evolution. Here, the fittest cell is one that survives to form a new population of genetically distinct cells, the tumor. This review does not attempt to be comprehensive but

  16. Male mating biology

    Directory of Open Access Journals (Sweden)

    Howell Paul I

    2009-11-01

    Full Text Available Abstract Before sterile mass-reared mosquitoes are released in an attempt to control local populations, many facets of male mating biology need to be elucidated. Large knowledge gaps exist in how both sexes meet in space and time, the correlation of male size and mating success and in which arenas matings are successful. Previous failures in mosquito sterile insect technique (SIT projects have been linked to poor knowledge of local mating behaviours or the selection of deleterious phenotypes during colonisation and long-term mass rearing. Careful selection of mating characteristics must be combined with intensive field trials to ensure phenotypic characters are not antagonistic to longevity, dispersal, or mating behaviours in released males. Success has been achieved, even when colonised vectors were less competitive, due in part to extensive field trials to ensure mating compatibility and effective dispersal. The study of male mating biology in other dipterans has improved the success of operational SIT programmes. Contributing factors include inter-sexual selection, pheromone based attraction, the ability to detect alterations in local mating behaviours, and the effects of long-term colonisation on mating competitiveness. Although great strides have been made in other SIT programmes, this knowledge may not be germane to anophelines, and this has led to a recent increase in research in this area.

  17. RNA protects a nucleoprotein complex against radiation damage.

    Science.gov (United States)

    Bury, Charles S; McGeehan, John E; Antson, Alfred A; Carmichael, Ian; Gerstel, Markus; Shevtsov, Mikhail B; Garman, Elspeth F

    2016-05-01

    Radiation damage during macromolecular X-ray crystallographic data collection is still the main impediment for many macromolecular structure determinations. Even when an eventual model results from the crystallographic pipeline, the manifestations of radiation-induced structural and conformation changes, the so-called specific damage, within crystalline macromolecules can lead to false interpretations of biological mechanisms. Although this has been well characterized within protein crystals, far less is known about specific damage effects within the larger class of nucleoprotein complexes. Here, a methodology has been developed whereby per-atom density changes could be quantified with increasing dose over a wide (1.3-25.0 MGy) range and at higher resolution (1.98 Å) than the previous systematic specific damage study on a protein-DNA complex. Specific damage manifestations were determined within the large trp RNA-binding attenuation protein (TRAP) bound to a single-stranded RNA that forms a belt around the protein. Over a large dose range, the RNA was found to be far less susceptible to radiation-induced chemical changes than the protein. The availability of two TRAP molecules in the asymmetric unit, of which only one contained bound RNA, allowed a controlled investigation into the exact role of RNA binding in protein specific damage susceptibility. The 11-fold symmetry within each TRAP ring permitted statistically significant analysis of the Glu and Asp damage patterns, with RNA binding unexpectedly being observed to protect these otherwise highly sensitive residues within the 11 RNA-binding pockets distributed around the outside of the protein molecule. Additionally, the method enabled a quantification of the reduction in radiation-induced Lys and Phe disordering upon RNA binding directly from the electron density. PMID:27139628

  18. Cerium oxide nanoparticles, combining antioxidant and UV shielding properties, prevent UV-induced cell damage and mutagenesis

    Science.gov (United States)

    Caputo, Fanny; de Nicola, Milena; Sienkiewicz, Andrzej; Giovanetti, Anna; Bejarano, Ignacio; Licoccia, Silvia; Traversa, Enrico; Ghibelli, Lina

    2015-09-01

    Efficient inorganic UV shields, mostly based on refracting TiO2 particles, have dramatically changed the sun exposure habits. Unfortunately, health concerns have emerged from the pro-oxidant photocatalytic effect of UV-irradiated TiO2, which mediates toxic effects on cells. Therefore, improvements in cosmetic solar shield technology are a strong priority. CeO2 nanoparticles are not only UV refractors but also potent biological antioxidants due to the surface 3+/4+ valency switch, which confers anti-inflammatory, anti-ageing and therapeutic properties. Herein, UV irradiation protocols were set up, allowing selective study of the extra-shielding effects of CeO2vs. TiO2 nanoparticles on reporter cells. TiO2 irradiated with UV (especially UVA) exerted strong photocatalytic effects, superimposing their pro-oxidant, cell-damaging and mutagenic action when induced by UV, thereby worsening the UV toxicity. On the contrary, irradiated CeO2 nanoparticles, via their Ce3+/Ce4+ redox couple, exerted impressive protection on UV-treated cells, by buffering oxidation, preserving viability and proliferation, reducing DNA damage and accelerating repair; strikingly, they almost eliminated mutagenesis, thus acting as an important tool to prevent skin cancer. Interestingly, CeO2 nanoparticles also protect cells from the damage induced by irradiated TiO2, suggesting that these two particles may also complement their effects in solar lotions. CeO2 nanoparticles, which intrinsically couple UV shielding with biological and genetic protection, appear to be ideal candidates for next-generation sun shields.

  19. Cerium oxide nanoparticles, combining antioxidant and UV shielding properties, prevent UV-induced cell damage and mutagenesis

    KAUST Repository

    Caputo, Fanny

    2015-08-20

    Efficient inorganic UV shields, mostly based on refracting TiO2 particles, have dramatically changed the sun exposure habits. Unfortunately, health concerns have emerged from the pro-oxidant photocatalytic effect of UV-irradiated TiO2, which mediates toxic effects on cells. Therefore, improvements in cosmetic solar shield technology are a strong priority. CeO2 nanoparticles are not only UV refractors but also potent biological antioxidants due to the surface 3+/4+ valency switch, which confers anti-inflammatory, anti-ageing and therapeutic properties. Herein, UV irradiation protocols were set up, allowing selective study of the extra-shielding effects of CeO2vs. TiO2 nanoparticles on reporter cells. TiO2 irradiated with UV (especially UVA) exerted strong photocatalytic effects, superimposing their pro-oxidant, cell-damaging and mutagenic action when induced by UV, thereby worsening the UV toxicity. On the contrary, irradiated CeO2 nanoparticles, via their Ce3+/Ce4+ redox couple, exerted impressive protection on UV-treated cells, by buffering oxidation, preserving viability and proliferation, reducing DNA damage and accelerating repair; strikingly, they almost eliminated mutagenesis, thus acting as an important tool to prevent skin cancer. Interestingly, CeO2 nanoparticles also protect cells from the damage induced by irradiated TiO2, suggesting that these two particles may also complement their effects in solar lotions. CeO2 nanoparticles, which intrinsically couple UV shielding with biological and genetic protection, appear to be ideal candidates for next-generation sun shields. © The Royal Society of Chemistry 2015.

  20. Psoriatic arthritis: treatment strategies using biologic agents

    Directory of Open Access Journals (Sweden)

    C. Palazzi

    2012-06-01

    Full Text Available The traditional management of psoriatic arthritis (PsA includes NSAIDs, corticosteroids and DMARDs. Advancement in the knowledge of the immunopathogenesis of PsA has been associated with the development of biologic agents which have revolutionized the management of the disease. Among biologics drugs, there are the 4 currently availablee anti-TNFα blocking agents (etanercept, infliximab, adalimumab and golimumab which are more effective than traditional DMARDs on symptoms/signs of inflammation, quality of life, function, and in inhibiting the progression of the structural joint damage. Despite of the high cost, TNF inhibitors are costeffective on both the musculoskeletal and skin manifestations of psoriatic disease.