Car-borne survey of natural background gamma dose rate in Canakkale region (Turkey)

International Nuclear Information System (INIS)

Turhan, S.; Arikan, I. H.; Oquz, F.; Aezdemir, T.; Yuecel, B.; Varinlioqlu, A.; Koese, A.

2012-01-01

Natural background gamma radiation was measured along roads in the environs of Canakkale region by using a car-borne spectrometer system with a plastic gamma radiation detector. In addition, activity concentrations of 238 U, 226 Ra, 232 Th and 40 K in soil samples from the Canakkale region were determined by using a gamma spectrometer with an HPGe detector. A total of 92 856 data of the background gamma dose rate were collected for the Canakkale region. The background gamma dose rate of the Canakkale region was mapped using ArcGIS software, applying the geostatistical inverse distance-weighted method. The average and population-weighted average of the gamma dose are 55.4 and 40.6 nGy h -1 , respectively. The corresponding average annual effective dose to the public ranged from 26.6 to 96.8 μSv. (authors)

Enhanced stimulus-induced gamma activity in humans during propofol-induced sedation.

Directory of Open Access Journals (Sweden)

Neeraj Saxena

Full Text Available Stimulus-induced gamma oscillations in the 30-80 Hz range have been implicated in a wide number of functions including visual processing, memory and attention. While occipital gamma-band oscillations can be pharmacologically modified in animal preparations, pharmacological modulation of stimulus-induced visual gamma oscillations has yet to be demonstrated in non-invasive human recordings. Here, in fifteen healthy humans volunteers, we probed the effects of the GABAA agonist and sedative propofol on stimulus-related gamma activity recorded with magnetoencephalography, using a simple visual grating stimulus designed to elicit gamma oscillations in the primary visual cortex. During propofol sedation as compared to the normal awake state, a significant 60% increase in stimulus-induced gamma amplitude was seen together with a 94% enhancement of stimulus-induced alpha suppression and a simultaneous reduction in the amplitude of the pattern-onset evoked response. These data demonstrate, that propofol-induced sedation is accompanied by increased stimulus-induced gamma activity providing a potential window into mechanisms of gamma-oscillation generation in humans.

The Utilization of Background Spectrum to Calibrate Gamma Spectrometry

International Nuclear Information System (INIS)

Mahrouka, M. M.; Mutawa, A. M.

2004-01-01

Many developed countries have very poor reference standards to calibrate their nuclear instrumentations or may find some difficulties to obtain a reference standard. In this work a simple way for Gamma spectrometry calibration was developed. The method depends on one reference point and additional points from the background. The two derived equations were applied to the analyses of radioactive nuclides in soil and liquid samples prepared by IAEA laboratories through AL MERA Project. The results showed the precision of the methodology used, as well as, the possibility of using some points in the background spectrum as a replacement for reference standards of Gamma spectrometry calibration. (authors)

Revealing dark matter substructure with anisotropies in the diffuse gamma-ray background

International Nuclear Information System (INIS)

Siegal-Gaskins, Jennifer M

2008-01-01

The majority of gamma-ray emission from galactic dark matter annihilation is likely to be detected as a contribution to the diffuse gamma-ray background. I show that dark matter substructure in the halo of the Galaxy induces characteristic anisotropies in the diffuse background that could be used to determine the small-scale dark matter distribution. I calculate the angular power spectrum of the emission from dark matter substructure for several models of the subhalo population and show that features in the power spectrum can be used to infer the presence of substructure. The shape of the power spectrum is largely unaffected by the subhalo radial distribution and mass function, and for many scenarios I find that a measurement of the angular power spectrum by Fermi will be able to constrain the abundance of substructure. An anti-biased subhalo radial distribution is shown to produce emission that differs significantly in intensity and large-scale angular dependence from that of a subhalo distribution which traces the smooth dark matter halo, potentially impacting the detectability of the dark matter signal for a variety of targets and methods

Revealing dark matter substructure with anisotropies in the diffuse gamma-ray background

Energy Technology Data Exchange (ETDEWEB)

Siegal-Gaskins, Jennifer M, E-mail: jsg@kicp.uchicago.edu [Kavli Institute for Cosmological Physics and Department of Physics, University of Chicago, 5640 S. Ellis Avenue, Chicago, IL 60637 (United States)

2008-10-15

The majority of gamma-ray emission from galactic dark matter annihilation is likely to be detected as a contribution to the diffuse gamma-ray background. I show that dark matter substructure in the halo of the Galaxy induces characteristic anisotropies in the diffuse background that could be used to determine the small-scale dark matter distribution. I calculate the angular power spectrum of the emission from dark matter substructure for several models of the subhalo population and show that features in the power spectrum can be used to infer the presence of substructure. The shape of the power spectrum is largely unaffected by the subhalo radial distribution and mass function, and for many scenarios I find that a measurement of the angular power spectrum by Fermi will be able to constrain the abundance of substructure. An anti-biased subhalo radial distribution is shown to produce emission that differs significantly in intensity and large-scale angular dependence from that of a subhalo distribution which traces the smooth dark matter halo, potentially impacting the detectability of the dark matter signal for a variety of targets and methods.

The angular power spectrum of the diffuse gamma-ray background as a probe of Galactic dark matter substructure

OpenAIRE

Siegal-Gaskins, Jennifer M.

2009-01-01

Dark matter annihilation in Galactic substructure produces diffuse gamma-ray emission of remarkably constant intensity across the sky, and in general this signal dominates over the smooth halo signal at angles greater than a few tens of degrees from the Galactic Center. The large-scale isotropy of the emission from substructure suggests that it may be difficult to extract this Galactic dark matter signal from the extragalactic gamma-ray background. I show that dark matter substructure induces...

A low-background gamma-ray assay laboratory for activation analysis

International Nuclear Information System (INIS)

Lindstrom, R.M.; Langland, J.K.; Lindstrom, D.J.; Slaback, L.A.

1990-01-01

The sources of background in a gamma-ray detector were experimentally determined in underground and surface counting rooms, and an optimized shield was constructed at NIST. The optimum thickness of lead was 10-15 cm, with a greater thickness giving an increased background due to the buildup of tertiary cosmic-ray particles. Neither cadmium, tin, copper nor plastic (hydrocarbon or fluorocarbon) was desirable as a shield liner, since all these increased the background continuum or introduced characteristic peaks into the background spectrum. Two broad peaks in the background result from inelastic scattering of cosmic-ray neutrons (0.02 cm -2 s -1 ) in germanium. These neutrons also excite the lower nuclear levels of lead and structural iron to produce additional gamma-ray peaks in the spectrum. The influence of the 20 MW NIST reactor, located 60 m from the detector, was undetectable. Comparisons among detectors and locations clearly separate cosmic from environmental components of the background. (orig.)

A low-background gamma-ray assay laboratory for activation analysis

Energy Technology Data Exchange (ETDEWEB)

Lindstrom, R M; Langland, J K [National Inst. of Standards and Technology, Gaithersburg, MD (USA). Center for Analytical Chemistry; Lindstrom, D J [National Aeronautics and Space Administration, Houston, TX (USA). Lyndon B. Johnson Space Center; Slaback, L A [National Inst. of Standards and Technology, Gaithersburg, MD (USA). Occupational Health and Safety Div.

1990-12-20

The sources of background in a gamma-ray detector were experimentally determined in underground and surface counting rooms, and an optimized shield was constructed at NIST. The optimum thickness of lead was 10-15 cm, with a greater thickness giving an increased background due to the buildup of tertiary cosmic-ray particles. Neither cadmium, tin, copper nor plastic (hydrocarbon or fluorocarbon) was desirable as a shield liner, since all these increased the background continuum or introduced characteristic peaks into the background spectrum. Two broad peaks in the background result from inelastic scattering of cosmic-ray neutrons (0.02 cm{sup -2} s{sup -1}) in germanium. These neutrons also excite the lower nuclear levels of lead and structural iron to produce additional gamma-ray peaks in the spectrum. The influence of the 20 MW NIST reactor, located 60 m from the detector, was undetectable. Comparisons among detectors and locations clearly separate cosmic from environmental components of the background. (orig.).

Environmental gamma background measurements in China Jinping Underground Laboratory

International Nuclear Information System (INIS)

Zhi Zeng; Jian Su; Hao Ma; Hengguan Yi; Jianping Cheng; Qian Yue; Junli Li; Hui Zhang

2014-01-01

To determine the environmental gamma background levels which affects rare events experiments, we measured in situ gamma spectrum at four locations in the China Jinping Underground Laboratory. The integral background count rates (40-2,700 keV) varied from 3.76 to 74.1 cps. The average count rate of the measurements inside the CJPL was 73.4 cps. The spectrometer was calibrated with a 152 Eu point source and Monte Carlo simulation to obtain the activity conversion factors for the rock and the air, respectively. The rocks that surrounded the CJPL was characterized by very low activity concentrations of 238 U (3.69-4.21 Bq kg -1 ), 232 Th (0.52-0.64 Bq kg -1 ) and 40 K (4.28 Bq kg -1 ). (author)

Origin of the diffuse background gamma radiation

International Nuclear Information System (INIS)

Stecker, F.W.; Puget, J.L.

1974-05-01

Recent observations have now provided evidence for diffuse background gamma radiation extending to energies beyond 100 MeV. There is some evidence of isotropy and implied cosmological origin. Significant features in the spectrum of this background radiation were observed which provide evidence for its origin in nuclear processes in the early stages of the big-band cosmology and tie in these processes with galaxy formation theory. A crucial test of the theory may lie in future observations of the background radiation in the 100 MeV to 100 GeV energy range which may be made with large orbiting spark-chamber satellite detectors. A discussion of the theoretical interpretations of present data, their connection with baryon symmetric cosmology and galaxy formation theory, and the need for future observations are given. (U.S.)

Study of proton beam induced gamma background in metallic backings

CERN Document Server

Gyuerky, G; Somorjai, E

2003-01-01

A low mass star burns H in the center via the pp chain. The central temperature (and the density) increases and the H-burning switches from the pp-chain to the more efficient CNO-burning. The escape of the star from the Main Sequence is powered by the onset of the CNO burning, whose bottleneck is the sup 1 sup 4 N(p,gamma) sup 1 sup 5 O reaction. Thus direct measurements of the sup 1 sup 4 N(p,gamma) sup 1 sup 5 O reaction at very low energies are needed. (R.P.)

Effect of gamma background on the dose absorbed by human embryon and foetus

International Nuclear Information System (INIS)

Miloslavov, V.; Doncheva, B.

1989-01-01

A method is proposed for calculation of absorbed radiation dose in different stages of human foetus development under normal or increased gamma background. On the base of ICRP-data for critical organ's mass (foetus, placenta, blood, uterus) a formula is given for absorbed dose evaluation of gonads. It is concluded that increased gamma background is insignificant compared to internal irradiation from absorbed radionuclides

The Extragalactic Background Light and the Gamma-ray Opacity of the Universe

Science.gov (United States)

Dwek, Eli; Krennrich, Frank

2012-01-01

The extragalactic background light (EBL) is one of the fundamental observational quantities in cosmology. All energy releases from resolved and unresolved extragalactic sources, and the light from any truly diffuse background, excluding the cosmic microwave background (CMB), contribute to its intensity and spectral energy distribution. It therefore plays a crucial role in cosmological tests for the formation and evolution of stellar objects and galaxies, and for setting limits on exotic energy releases in the universe. The EBL also plays an important role in the propagation of very high energy gamma-rays which are attenuated en route to Earth by pair producing gamma-gamma interactions with the EBL and CMB. The EBL affects the spectrum of the sources, predominantly blazars, in the approx 10 GeV to 10 TeV energy regime. Knowledge of the EBL intensity and spectrum will allow the determination of the intrinsic blazar spectrum in a crucial energy regime that can be used to test particle acceleration mechanisms and VHE gamma-ray production models. Conversely, knowledge of the intrinsic gamma-ray spectrum and the detection of blazars at increasingly higher redshifts will set strong limits on the EBL and its evolution. This paper reviews the latest developments in the determination of the EBL and its impact on the current understanding of the origin and production mechanisms of gamma-rays in blazars, and on energy releases in the universe. The review concludes with a summary and future directions in Cherenkov Telescope Array techniques and in infrared ground-based and space observatories that will greatly improve our knowledge of the EBL and the origin and production of very high energy gamma-rays.

Effect of high gamma background on neutron sensitivity of fission detectors

International Nuclear Information System (INIS)

Balagi, V.; Prasad, K.R.; Kataria, S.K.

2004-01-01

Tests were performed on two parallel plate and two cylindrical fission detectors in pulse and dc mode. The effect of gamma background on neutron sensitivity was studied in thermal neutron flux from 30 nv to 60 nv over which gamma field intensity ranging from 230 kR/h to 3.7 MR/h was superposed. In the case of one of the parallel plate detectors the fall in neutron sensitivity was observed to be 3.7% at 1 MR/h and negligible below 1 MR/h. In the case of one of the cylindrical counters the fall in neutron sensitivity was negligible below 500 kR/h and 37% at 1 MR/h. The data was used to derive the design parameters for a wide range fission detector to be procured for PFBR instrumentation for operation at 600 degC and gamma background of 1 MR/h. (author)

Timing of Pulsed Prompt Gamma Rays for Background Discrimination

International Nuclear Information System (INIS)

Hueso-Gonzalez, F.; Golnik, C.; Berthel, M.; Dreyer, A.; Kormoll, T.; Rohling, H.; Pausch, G.; Enghardt, W.; Fiedler, F.; Heidel, K.; Schoene, S.; Schwengner, R.; Wagner, A.

2013-06-01

In the context of particle therapy, particle range verification is a major challenge for the quality assurance of the treatment. One approach is the measurement of the prompt gamma rays resulting from the tissue irradiation. A Compton camera based on several planes of position sensitive gamma ray detectors, together with an imaging algorithm, is expected to reconstruct the prompt gamma ray emission density profile, which is correlated with the dose distribution. At Helmholtz- Zentrum Dresden-Rossendorf (HZDR) and OncoRay, a camera prototype has been developed consisting of two scatter planes (CdZnTe cross strip detectors) and an absorber plane (Lu 2 SiO 5 block detector). The data acquisition is based on VME electronics and handled by software developed on the ROOT platform. The prototype was tested at the linear electron accelerator ELBE at HZDR, which was set up to produce bunched bremsstrahlung photons. Their spectrum has similarities with the one expected from prompt gamma rays in the clinical case, and these are also bunched with the accelerator frequency. The time correlation between the pulsed prompt photons and the measured signals was used for background discrimination, achieving a time resolution of 3 ns (2 ns) FWHM for the CZT (LSO) detector. A time-walk correction was applied for the LSO detector and improved its resolution to 1 ns. In conclusion, the detectors are suitable for time-resolved background discrimination in pulsed clinical particle accelerators. Ongoing tasks are the test of the imaging algorithms and the quantitative comparison with simulations. Further experiments will be performed at proton accelerators. (authors)

Low background gamma ray spectrometer using the anticoincidence shield technique at KAERI

International Nuclear Information System (INIS)

Byun, Jong In; Choi, Yun Ho; Kwak, Seung Im; Hwang, Han Yull; Chung, Kun Ho; Choi, Geun Sik; Park, Doo Won; Lee, Chang Woo

2002-01-01

We develop a ultra-low background gamma ray spectrometer, using active and passive shielding technique at the same time. Cosmic ray induced background is suppressed by means of active shield devices consisting of plastic scintillating plates of 50 mm thick and anti-coincidence electronic system. The shield is made of 150 mm thick walls of very low activity lead, especially 20 mm with activity of -1 and 0.36 s -1 with and without active shield, respectively, on the regions from 50 keV to 3 MeV. The detection efficiency curve has been precisely measured for regions from 80 keV to 2 MeV with a 10 3 ml marinelli beaker sample, made with calibrated mixed-sources consists of 109 Cd, 57 Co, 139 Ce, 203 Hg, 113 Sn, 85 Sr, 137 Cs, 60 Co and 88 Y. The virtues of the method are demonstrated by applying on experiment that requires the lowest detection limit

Cosmic gamma-ray background from dark matter annihilation

International Nuclear Information System (INIS)

Ando, Shin'ichiro

2007-01-01

High-energy photons from pair annihilation of dark matter particles contribute to the cosmic gamma-ray background (CGB) observed in a wide energy range. The precise shape of the energy spectrum of CGB depends on the nature of dark matter particles. In order to discriminate between the signals from dark matter annihilation and other astrophysical sources, however, the information from the energy spectrum of CGB may not be sufficient. We show that dark matter annihilation not only contributes to the mean CGB intensity, but also produces a characteristic anisotropy, which provides a powerful tool for testing the origins of the observed CGB. We show that the expected sensitivity of future gamma-ray detectors such as GLAST should allow us to measure the angular power spectrum of CGB anisotropy, if dark matter particles are supersymmetric neutralinos and they account for most of the observed mean intensity. As the intensity of photons from annihilation is proportional to the density squared, we show that the predicted shape of the angular power spectrum of gamma rays from dark matter annihilation is different from that due to other astrophysical sources such as blazars, whose intensity is linearly proportional to density. Therefore, the angular power spectrum of the CGB provides a 'smoking-gun' signature of gamma rays from dark matter annihilation

Real-time airborne gamma-ray background estimation using NASVD with MLE and radiation transport for calibration

Energy Technology Data Exchange (ETDEWEB)

Kulisek, J.A., E-mail: Jonathan.Kulisek@pnnl.gov; Schweppe, J.E.; Stave, S.C.; Bernacki, B.E.; Jordan, D.V.; Stewart, T.N.; Seifert, C.E.; Kernan, W.J.

2015-06-01

Helicopter-mounted gamma-ray detectors can provide law enforcement officials the means to quickly and accurately detect, identify, and locate radiological threats over a wide geographical area. The ability to accurately distinguish radiological threat-generated gamma-ray signatures from background gamma radiation in real time is essential in order to realize this potential. This problem is non-trivial, especially in urban environments for which the background may change very rapidly during flight. This exacerbates the challenge of estimating background due to the poor counting statistics inherent in real-time airborne gamma-ray spectroscopy measurements. To address this challenge, we have developed a new technique for real-time estimation of background gamma radiation from aerial measurements without the need for human analyst intervention. The method can be calibrated using radiation transport simulations along with data from previous flights over areas for which the isotopic composition need not be known. Over the examined measured and simulated data sets, the method generated accurate background estimates even in the presence of a strong, {sup 60}Co source. The potential to track large and abrupt changes in background spectral shape and magnitude was demonstrated. The method can be implemented fairly easily in most modern computing languages and environments.

Gamma-induced Positron Spectroscopy (GiPS) at a superconducting electron linear accelerator

International Nuclear Information System (INIS)

Butterling, Maik; Anwand, Wolfgang; Cowan, Thomas E.; Hartmann, Andreas; Jungmann, Marco; Krause-Rehberg, Reinhard; Krille, Arnold; Wagner, Andreas

2011-01-01

A new and unique setup for Positron Annihilation Spectroscopy has been established and optimized at the superconducting linear electron accelerator ELBE at Helmholtz-Zentrum Dresden-Rossendorf (Germany). The intense, pulsed (26 MHz) photon source (bremsstrahlung with energies up to 16 MeV) is used to generate positrons by means of pair production throughout the entire sample volume. Due to the very short gamma bunches (< 5 ps temporal length), the facility for Gamma-induced Positron Spectroscopy (GiPS) is suitable for positron lifetime spectroscopy using the accelerator's radiofrequency as time reference. Positron lifetime and Doppler broadening Spectroscopy are employed by a coincident measurement (Age-Momentum Correlation) of the time-of-arrival and energy of the annihilation photons which in turn significantly reduces the background of scattered photons resulting in spectra with high signal to background ratios. Simulations of the setup using the GEANT4 framework have been performed to yield optimum positron generation rates for various sample materials and improved background conditions.

Gamma-induced Positron Spectroscopy (GiPS) at a superconducting electron linear accelerator

Energy Technology Data Exchange (ETDEWEB)

Butterling, Maik, E-mail: maik.butterling@googlemail.com [Martin-Luther University, Dept. of Physics, 06099 Halle (Germany); Institute of Radiation Physics, Helmholtz-Zentrum, Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden (Germany); Anwand, Wolfgang; Cowan, Thomas E.; Hartmann, Andreas [Institute of Radiation Physics, Helmholtz-Zentrum, Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden (Germany); Jungmann, Marco; Krause-Rehberg, Reinhard [Martin-Luther University, Dept. of Physics, 06099 Halle (Germany); Krille, Arnold; Wagner, Andreas [Institute of Radiation Physics, Helmholtz-Zentrum, Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden (Germany)

2011-11-15

A new and unique setup for Positron Annihilation Spectroscopy has been established and optimized at the superconducting linear electron accelerator ELBE at Helmholtz-Zentrum Dresden-Rossendorf (Germany). The intense, pulsed (26 MHz) photon source (bremsstrahlung with energies up to 16 MeV) is used to generate positrons by means of pair production throughout the entire sample volume. Due to the very short gamma bunches (< 5 ps temporal length), the facility for Gamma-induced Positron Spectroscopy (GiPS) is suitable for positron lifetime spectroscopy using the accelerator's radiofrequency as time reference. Positron lifetime and Doppler broadening Spectroscopy are employed by a coincident measurement (Age-Momentum Correlation) of the time-of-arrival and energy of the annihilation photons which in turn significantly reduces the background of scattered photons resulting in spectra with high signal to background ratios. Simulations of the setup using the GEANT4 framework have been performed to yield optimum positron generation rates for various sample materials and improved background conditions.

An ultralow background germanium gamma-ray spectrometer

International Nuclear Information System (INIS)

Reeves, R.H.; Brodzinski, R.L.; Hensley, W.K.; Ryge, P.

1984-01-01

The monitoring of minimum detectable activity is becoming increasingly important as environmental concerns and regulations require more sensitive measurement of the radioactivity levels in the workplace and the home. In measuring this activity, however, the background becomes one of the limiting factors. Anticoincidence systems utilizing both NaI(T1) and plastic scintillators have proven effective in reducing some components of the background, but radiocontaminants in the various regions of these systems have limited their effectiveness, and their cost is often prohibitive. In order to obtain a genuinely low background detector system, all components must be free of detectable radioactivity, and the cosmic ray produced contribution must be significantly reduced. Current efforts by the authors to measure the double beta decay of Germanium 76 as predicted by Grand Unified Theories have resulted in the development of a high resolution germanium diode gamma spectrometer with an exceptionally low background. This paper describes the development of this system, outlines the configuration and operation of its preamplifier, linear amplifier, analog-to-digital converter, 4096-channel analyzer, shielding consisting of lead-sandwiched plastic scintillators wrapped in cadmium foil, photomultiplier, and its pulse generator and discriminator, and then discusses how the system can be utilized to significantly reduce the background in high resolution photon spectrometers at only moderate cost

Gamma background irradiation. Standards and reality

International Nuclear Information System (INIS)

Miloslavov, V.

1998-01-01

The systematic deviation of the results of measuring the power of air dose absorbed from the natural gamma background radiation in Bulgaria is inadmissibly large and variable. This in turn augments the dispersion of results as well as the mean value relative to worldwide data, to an implausible level, hardly attributable to the variegated geographical relief of the country. Thus in practice local anthropogenic increases hardly lend themselves to detection and demonstration. In the Radiation Protection Standards (RPS-92) in effect in Bulgaria, and in other documents concerning the same radiation factors as well, the maximum allowable limits for the population as a whole are clearly specified on the basis of worldwide expertise along this line. As a rule these limits are being exceeded by the actually measured values, and for this reason the cited documents contain a clause stipulating that these limits do not refer to the natural radiation background and therefore the latter may be virtually ignored. Thus the basic risk factor for the population goes beyond control at levels commensurable with the officially established limits, its twofold increase inclusive. The maximum allowable limit becomes undefinable. Bearing in mind the fact that in compliance with the cited RPS-92 elimination of the technogenic ionizing radiation sources incorporated in the environment prior to 1992 is 'freezed', it is evident that exposure of the population to anthropogenic radiation becomes legally allowable in a much wider range than the one specified by world legislators. One may anticipate radiation induced health noxae for the population directly or by anthropogenic radiation stress on biocenosis. A relatively large part of the population is susceptible to the effect of low radiation doses. Presumably this contingent will augment as a result of eventual fluctuations. The casual relationship which is difficult to establish should be given due consideration in the analysis of the causes

An automated background estimation procedure for gamma ray spectra

International Nuclear Information System (INIS)

Tervo, R.J.; Kennett, T.J.; Prestwich, W.V.

1983-01-01

An objective and simple method has been developed to estimate the background continuum in Ge gamma ray spectra. Requiring no special procedures, the method is readily automated. Based upon the inherent statistical properties of the experimental data itself, nodes, which reflect background samples are located and used to produce an estimate of the continuum. A simple procedure to interpolate between nodes is reported and a range of rather typical experimental data is presented. All information necessary to implemented this technique is given including the relevant properties of various factors involved in its development. (orig.)

A novel background reduction strategy for high level triggers and processing in gamma-ray Cherenkov detectors

International Nuclear Information System (INIS)

Cabras, G.; De Angelis, A.; De Lotto, B.; De Maria, M. M.; De Sabata, F.; Mansutti, O.; Frailis, M.; Persic, M.; Bigongiari, C.; Doro, M.; Mariotti, M.; Peruzzo, L.; Saggion, A.; Scalzotto, V.; Paoletti, R.; Scribano, A.; Turini, N.; Moralejo, A.; Tescaro, D.

2008-01-01

Gamma ray astronomy is now at the leading edge for studies related both to fundamental physics and astrophysics. The sensitivity of gamma detectors is limited by the huge amount of background, constituted by hadronic cosmic rays (typically two to three orders of magnitude more than the signal) and by the accidental background in the detectors. By using the information on the temporal evolution of the Cherenkov light, the background can be reduced. We will present here the results obtained within the MAGIC experiment using a new technique for the reduction of the background. Particle showers produced by gamma rays show a different temporal distribution with respect to showers produced by hadrons; the background due to accidental counts shows no dependence on time. Such novel strategy can increase the sensitivity of present instruments

Analysis of coincidence {gamma}-ray spectra using advanced background elimination, unfolding and fitting algorithms

Energy Technology Data Exchange (ETDEWEB)

Morhac, M. E-mail: fyzimiro@savba.skfyzimiro@flnr.jinr.ru; Matousek, V. E-mail: matousek@savba.sk; Kliman, J.; Krupa, L.L.; Jandel, M

2003-04-21

The efficient algorithms to analyze multiparameter {gamma}-ray spectra are presented. They allow to search for peaks, to separate peaks from background, to improve the resolution and to fit 1-, 2-, 3-parameter {gamma}-ray spectra.

Neutron detection in a high gamma-ray background with EJ-301 and EJ-309 liquid scintillators

International Nuclear Information System (INIS)

Stevanato, L.; Cester, D.; Nebbia, G.; Viesti, G.

2012-01-01

Using a fast digitizer, the neutron–gamma discrimination capability of the new liquid scintillator EJ-309 is compared with that obtained using standard EJ-301. Moreover the capability of both the scintillation detectors to identify a weak neutron source in a high gamma-ray background is demonstrated. The probability of neutron detection is PD=95% at 95% confidence level for a gamma-ray background corresponding to a dose rate of 100 μSv/h.

Shielding of the GERDA experiment against external gamma background

International Nuclear Information System (INIS)

Barabanov, I.; Bezrukov, L.; Demidova, E.; Gurentsov, V.; Kianovsky, S.; Knoepfle, K.T.; Kornouhkov, V.; Schwingenheuer, B.; Vasenko, A.

2009-01-01

The GERmanium Detector Array (GERDA) experiment will search for neutrinoless double beta decay of 76 Ge and is currently under construction at the INFN Laboratori Nazionali del Gran Sasso (LNGS) in Italy. The basic design of GERDA is the use of cryogenic liquid and water of high purity as a superior shield against the hitherto dominant background from external gamma radiation. In this paper we show by Monte Carlo simulations and analytical calculations how GERDA was designed to suppress this background at Q ββ ( 76 Ge)=2039keV to a level of about 10 -4 cts/(keVkgy).

Gamma-ray Background Spectrum and Annihilation Rate in the Baryon-symmetric Big-bang Cosmology

Science.gov (United States)

Puget, J. L.

1973-01-01

An attempt was made to acquire experimental information on the problem of baryon symmetry on a large cosmological scale by observing the annihilation products. Data cover absorption cross sections and background radiation due to other sources for the two main products of annihilation, gamma rays and neutrinos. Test results show that the best direct experimental test for the presence of large scale antimatter lies in the gamma ray background spectrum between 1 and 70 MeV.

Reduction of Compton background from hydrogen in prompt gamma-ray analysis by multiple photon detection

International Nuclear Information System (INIS)

Toh, Y.; Oshima, M.; Kimura, A.; Koizumi, M.; Furutaka, K.; Hatsukawa, Y.

2008-01-01

Low-energy photons produced by the Compton scattering from hydrogen increase the background in the lower-energy region of the gamma-ray spectrum. This results in an increase in the detection limit for trace elements. In multiple photon detection prompt gamma-ray analysis (MPGA), only those elements that simultaneously emit two or more prompt gamma-rays, which have cascade relation and are emitted within a short interval, can be measured. Therefore, the influence of hydrogen can be reduced. In this study, standard polymer and food samples are measured. The hydrogen background is reduced in MPGA. (author)

Measurement of background gamma radiation in the northern Marshall Islands.

Science.gov (United States)

Bordner, Autumn S; Crosswell, Danielle A; Katz, Ainsley O; Shah, Jill T; Zhang, Catherine R; Nikolic-Hughes, Ivana; Hughes, Emlyn W; Ruderman, Malvin A

2016-06-21

We report measurements of background gamma radiation levels on six islands in the northern Marshall Islands (Enewetak, Medren, and Runit onEnewetak Atoll; Bikini and Nam on Bikini Atoll; and Rongelap on Rongelap Atoll). Measurable excess radiation could be expected from the decay of (137)Cs produced by the US nuclear testing program there from 1946 to 1958. These recordings are of relevance to safety of human habitation and resettlement. We find low levels of gamma radiation for the settled island of Enewetak [mean = 7.6 millirem/year (mrem/y) = 0.076 millisievert/year (mSv/y)], larger levels of gamma radiation for the island of Rongelap (mean = 19.8 mrem/y = 0.198 mSv/y), and relatively high gamma radiation on the island of Bikini (mean = 184 mrem/y = 1.84 mSv/y). Distributions of gamma radiation levels are provided, and hot spots are discussed. We provide interpolated maps for four islands (Enewetak, Medren, Bikini, and Rongelap), and make comparisons to control measurements performed on the island of Majuro in the southern Marshall Islands, measurements made in Central Park in New York City, and the standard agreed upon by the United States and the Republic of the Marshall Islands (RMI) governments (100 mrem/y = 1 mSv/y). External gamma radiation levels on Bikini Island significantly exceed this standard (P = <0.01), and external gamma radiation levels on the other islands are below the standard. To determine conclusively whether these islands are safe for habitation, radiation exposure through additional pathways such as food ingestion must be considered.

Committed dose assessment based on background outdoor gamma exposure in Chihuahua City, Mexico

International Nuclear Information System (INIS)

Luevano G, S.; Perez T, A.; Pinedo A, C.; Renteria V, M.; Carrillo F, J.; Montero C, M. E.

2015-10-01

Full text: Determining ionizing radiation in a geographic area serves to assess its effects on populations health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the committed dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, annual effective dose, and the lifetime cancer risk, 48 sampling points were randomly selected along the Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Muller counter. At the same sites, 48 soil samples were taken to obtain the activity concentrations of 226 Ra, 232 Th, 40 K and their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Outdoor gamma dose rates ranged from 56 to 193 n Gy h -1 . Results indicated that lifetime effective dose to inhabitants of Chihuahua City is in average of 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of activity concentrations in soil were 51.8, 73.1, and 1096.5 Bq kg -1 , of 226 Ra, 232 Th and 40 K, respectively. From the analysis of the spatial distribution of 232 Th, 226 Ra, and 40 K is to north, to north-center, and to south of city, respectively. In conclusion, natural background gamma dose received by inhabitants of Chihuahua City is high and mainly due to geological characteristics of the zone. (Author)

Nature of gamma rays background radiation in new and old buildings of Qatar University

International Nuclear Information System (INIS)

Al-Houty, L.; Abou-Leila, H.; El-Kameesy, S.

1987-01-01

Measurements and analysis of gamma-background radiation spectrum in four different places of Qatar University campus were performed at the energy range 10 keV-3 MeV using hyper pure Ge-detector. The dependence of the detector absolute photopeak efficiency on gamma-ray energies was determined and correction of the data for that was also done. The absorbed dose for each gamma line was calculated and an estimation of the total absorbed dose for the detected gamma lines in the four different places was obtained. Comparison with other results was also performed

A novel background reduction strategy for high level triggers and processing in gamma-ray Cherenkov detectors

OpenAIRE

Cabras, G.; De Angelis, A.; De Lotto, B.; De Maria, M. M.; De Sabata, F.; Mansutti, O.; Frailis, M.; Persic, M.; Bigongiari, C.; Doro, M.; Mariotti, M.; Peruzzo, L.; Saggion, A.; Scalzotto, V.; Paoletti, R.

2008-01-01

Gamma ray astronomy is now at the leading edge for studies related both to fundamental physics and astrophysics. The sensitivity of gamma detectors is limited by the huge amount of background, constituted by hadronic cosmic rays (typically two to three orders of magnitude more than the signal) and by the accidental background in the detectors. By using the information on the temporal evolution of the Cherenkov light, the background can be reduced. We will present here the results obtained wit...

Committed dose assessment based on background outdoor gamma exposure in Chihuahua City, Mexico

Energy Technology Data Exchange (ETDEWEB)

Luevano G, S.; Perez T, A.; Pinedo A, C.; Renteria V, M. [Universidad Autonoma de Chihuahua, Facultad de Zootecnia y Ecologia, Perif. Francisco R. Almada Km 1, 31415 Chihuahua, Chih. (Mexico); Carrillo F, J.; Montero C, M. E., E-mail: mrenteria@uach.mx [Centro de Investigacion en Materiales Avanzados, Miguel de Cervantes 120, 31136 Chihuahua, Chih. (Mexico)

2015-10-15

Full text: Determining ionizing radiation in a geographic area serves to assess its effects on populations health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the committed dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, annual effective dose, and the lifetime cancer risk, 48 sampling points were randomly selected along the Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Muller counter. At the same sites, 48 soil samples were taken to obtain the activity concentrations of {sup 226}Ra, {sup 232}Th, {sup 40}K and their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Outdoor gamma dose rates ranged from 56 to 193 n Gy h{sup -1}. Results indicated that lifetime effective dose to inhabitants of Chihuahua City is in average of 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of activity concentrations in soil were 51.8, 73.1, and 1096.5 Bq kg{sup -1}, of {sup 226}Ra, {sup 232}Th and {sup 40}K, respectively. From the analysis of the spatial distribution of {sup 232}Th, {sup 226}Ra, and {sup 40}K is to north, to north-center, and to south of city, respectively. In conclusion, natural background gamma dose received by inhabitants of Chihuahua City is high and mainly due to geological characteristics of the zone. (Author)

Excision repair of gamma-ray-induced alkali-stable DNA lesions with the help of. gamma. -endonuclease from Micrococcus luteus

Energy Technology Data Exchange (ETDEWEB)

Tomilin, N V; Barenfeld, L S [AN SSSR, Leningrad. Inst. Tsitologii

1979-03-01

..gamma..-endonuclease Y, an enzyme that hydrolyses phosphodiester bonds at alkali-stable lesions in ..gamma..-irradiated (N/sub 2/, tris buffer) DNA, has been partially purified from Micrococcus luteus. The enzyme has a molecular weight of about 19 000, induces single-strand breaks with 3'OH-5'PO/sub 4/ termini and contains endonuclease activity towards DNA treated with 7-bromomethylbenz(a)anthracene. ..gamma..-endonuclease Y induces breaks in OsO/sub 4/-treated poly(dA-dT) and apparently is specific towards ..gamma..-ray-induced base lesions of the t' type. The complete excision repair of ..gamma..-endonuclease Y substrate sites has been performed in vitro by ..gamma..-endonuclease Y, DNA polymerase and ligase.

Design and applications of an anticoincidence shielded low background gamma-ray spectrometer

Energy Technology Data Exchange (ETDEWEB)

Petri, H [Forschungszentrum Juelich GmbH (Germany). Zentralabteilung fuer Chemische Analysen

1997-03-01

A low background gamma-ray spectrometer has been constructed for measuring artificial and natural radioative isotopes. The design of the spectrometer, its properties and the application to the determination of natural radioactivity of dental ceramics are described. (orig.)

THE DETECTABILITY OF DARK MATTER ANNIHILATION WITH FERMI USING THE ANISOTROPY ENERGY SPECTRUM OF THE GAMMA-RAY BACKGROUND

International Nuclear Information System (INIS)

Hensley, Brandon S.; Pavlidou, Vasiliki; Siegal-Gaskins, Jennifer M.

2010-01-01

The energy dependence of the anisotropy (the anisotropy energy spectrum) of the large-scale diffuse gamma-ray background can reveal the presence of multiple source populations. Annihilating dark matter in the substructure of the Milky Way halo could give rise to a modulation in the anisotropy energy spectrum of the diffuse gamma-ray emission measured by Fermi, enabling the detection of a dark matter signal. We determine the detectability of a dark-matter-induced modulation for scenarios in which unresolved blazars are the primary contributor to the measured emission above ∼1 GeV and find that in some scenarios pair-annihilation cross sections on the order of the value expected for thermal relic dark matter can produce a detectable feature. We anticipate that the sensitivity of this technique to specific dark matter models could be improved by tailored likelihood analysis methods.

Instrumental and atmospheric background lines observed by the SMM gamma-ray spectrometer

Science.gov (United States)

Share, G. H.; Kinzer, R. L.; Strickman, M. S.; Letaw, J. R.; Chupp, E. L.

1989-01-01

Preliminary identifications of instrumental and atmospheric background lines detected by the gamma-ray spectrometer on NASA's Solar Maximum Mission satellite (SMM) are presented. The long-term and stable operation of this experiment has provided data of high quality for use in this analysis. Methods are described for identifying radioactive isotopes which use their different decay times. Temporal evolution of the features are revealed by spectral comparisons, subtractions, and fits. An understanding of these temporal variations has enabled the data to be used for detecting celestial gamma-ray sources.

Lifetime Effective Dose Assessment Based on Background Outdoor Gamma Exposure in Chihuahua City, Mexico

Directory of Open Access Journals (Sweden)

Sergio Luevano-Gurrola

2015-09-01

Full Text Available Determining ionizing radiation in a geographic area serves to assess its effects on a population’s health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the annual effective dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, the annual effective dose and the lifetime cancer risk, 48 sampling points were randomly selected in Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Müller counter. Outdoor gamma dose rates ranged from 113 to 310 nGy·h−1. At the same sites, 48 soil samples were taken to obtain the activity concentrations of 226Ra, 232Th and 40K and to calculate their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Calculated gamma dose rates ranged from 56 to 193 nGy·h−1. Results indicated that the lifetime effective dose of the inhabitants of Chihuahua City is on average 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of the activity concentrations in soil were 52, 73 and 1097 Bq·kg−1, for 226Ra, 232Th and 40K, respectively. From the analysis, the spatial distribution of 232Th, 226Ra and 40K is to the north, to the north-center and to the south of city, respectively. In conclusion, the natural background gamma dose received by the inhabitants of Chihuahua City is high and mainly due to the geological characteristics of the zone. From the radiological point of view, this kind of study allows us to identify the importance of manmade environments, which are often highly variable and difficult to characterize.

Lifetime Effective Dose Assessment Based on Background Outdoor Gamma Exposure in Chihuahua City, Mexico.

Science.gov (United States)

Luevano-Gurrola, Sergio; Perez-Tapia, Angelica; Pinedo-Alvarez, Carmelo; Carrillo-Flores, Jorge; Montero-Cabrera, Maria Elena; Renteria-Villalobos, Marusia

2015-09-30

Determining ionizing radiation in a geographic area serves to assess its effects on a population's health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the annual effective dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, the annual effective dose and the lifetime cancer risk, 48 sampling points were randomly selected in Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Müller counter. Outdoor gamma dose rates ranged from 113 to 310 nGy·h(-1). At the same sites, 48 soil samples were taken to obtain the activity concentrations of (226)Ra, (232)Th and (40)K and to calculate their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Calculated gamma dose rates ranged from 56 to 193 nGy·h(-1). Results indicated that the lifetime effective dose of the inhabitants of Chihuahua City is on average 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of the activity concentrations in soil were 52, 73 and 1097 Bq·kg(-1), for (226)Ra, (232)Th and (40)K, respectively. From the analysis, the spatial distribution of (232)Th, (226)Ra and (40)K is to the north, to the north-center and to the south of city, respectively. In conclusion, the natural background gamma dose received by the inhabitants of Chihuahua City is high and mainly due to the geological characteristics of the zone. From the radiological point of view, this kind of study allows us to identify the importance of manmade environments, which are often highly variable and difficult to characterize.

Lifetime Effective Dose Assessment Based on Background Outdoor Gamma Exposure in Chihuahua City, Mexico

Science.gov (United States)

Luevano-Gurrola, Sergio; Perez-Tapia, Angelica; Pinedo-Alvarez, Carmelo; Carrillo-Flores, Jorge; Montero-Cabrera, Maria Elena; Renteria-Villalobos, Marusia

2015-01-01

Determining ionizing radiation in a geographic area serves to assess its effects on a population’s health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the annual effective dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, the annual effective dose and the lifetime cancer risk, 48 sampling points were randomly selected in Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Müller counter. Outdoor gamma dose rates ranged from 113 to 310 nGy·h−1. At the same sites, 48 soil samples were taken to obtain the activity concentrations of 226Ra, 232Th and 40K and to calculate their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Calculated gamma dose rates ranged from 56 to 193 nGy·h−1. Results indicated that the lifetime effective dose of the inhabitants of Chihuahua City is on average 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of the activity concentrations in soil were 52, 73 and 1097 Bq·kg−1, for 226Ra, 232Th and 40K, respectively. From the analysis, the spatial distribution of 232Th, 226Ra and 40K is to the north, to the north-center and to the south of city, respectively. In conclusion, the natural background gamma dose received by the inhabitants of Chihuahua City is high and mainly due to the geological characteristics of the zone. From the radiological point of view, this kind of study allows us to identify the importance of manmade environments, which are often highly variable and difficult to characterize. PMID:26437425

A study on the effect of gamma background in low power startup physics tests

International Nuclear Information System (INIS)

Bae, Chang Joon; Lee, Ki Bog

1993-01-01

Low power physics tests should be performed for the domestic pressurized light water reactors (PWRs) after refueling. The tests are performed to ensure that operating characteristics of the core are consistent with predictions and that the core can be operated as designed. But in some low power physics tests, slow but steady reactivity increasing phenomena were noticed after step reactivity insertion by the control rod movement. These reactivity increasing phenomena are due to the low flux level and the gamma backgroud because an uncompensated ion chamber (UIC) is used as the ex-core neutron detector. The gamma background may affect the results of the low power physics tests. The aims of this paper are to analyze the grounds of such phenomena, to simulate a reference bank worth measurement test and to present a resolution quantitatively. In this study, the gamma background level was estimated by numerically solving the point kinetics equations accounting the gamma background effect. The reactivity computer check test was simulated to verify the model. Also, an appropriate neutron flux level was determined by simulating the reference bank worth measurement test. The determined neutron flux level is approximately 0.3 of the nuclear heating flux. This level is about 3 times as high as the current test upper limit specified in the test procedure. Then, the findings from this work were successfully applied to Kori unit 4 cycle 7 and Yonggwang unit 1 cycle 7 physics tests. (Author)

Large-scale anisotropy in the extragalactic gamma-ray background as a probe for cosmological antimatter

Science.gov (United States)

Gao, Yi-Tian; Stecker, Floyd W.; Gleiser, Marcelo; Cline, David B.

1990-01-01

Intrinsic anisotropies in the extragalactic gamma-ray background (EGB), which should be detectable with the forthcoming Gamma Ray Observatory, can be used to examine some of the mechanisms proposed to explain its origin, one of which, the baryon-symmetric big bang (BSBB) model, is investigated here. In this simulation, large domains containing matter and antimatter galaxies produce gamma rays by annihilation at the domain boundaries. This mechanism can produce mountain-chain-shaped angular fluctuations in the EGB flux.

An evaluation of the background introduced from the coded aperture mask in the low energy gamma-ray telescope ZEBRA

International Nuclear Information System (INIS)

Butler, R.C.; Caroli, E.; Di Cocco, G.; Maggioli, P.P.; Spizzichino, A.; Charalambous, P.M.; Dean, A.J.; Drane, M.; Gil, A.; Stephen, J.B.; Perotti, F.; Villa, G.; Badiali, M.; La Padula, C.; Polcaro, F.; Ubertini, P.

1984-01-01

The background which arises from the presence of a coded aperture mask is evaluated. The major contributions which have been considered here are the interactions with the mask of the isotropic gamma-ray background, a parallel gamma-ray beam, neutrons and the effect of the mask element profile. It is shown that none of these factors conbribute to a significant excess or modulation in the background counting rate over the detection plane. In this way the use of a passive rather than an active coded aperture mask is seen to be suitable for use in a low energy gamma-ray telescope. (orig.)

Cosmic Connections:. from Cosmic Rays to Gamma Rays, Cosmic Backgrounds and Magnetic Fields

Science.gov (United States)

Kusenko, Alexander

2013-12-01

Combined data from gamma-ray telescopes and cosmic-ray detectors have produced some new surprising insights regarding intergalactic and galactic magnetic fields, as well as extragalactic background light. We review some recent advances, including a theory explaining the hard spectra of distant blazars and the measurements of intergalactic magnetic fields based on the spectra of distant sources. Furthermore, we discuss the possible contribution of transient galactic sources, such as past gamma-ray bursts and hypernova explosions in the Milky Way, to the observed ux of ultrahigh-energy cosmicrays nuclei. The need for a holistic treatment of gamma rays, cosmic rays, and magnetic fields serves as a unifying theme for these seemingly unrelated phenomena.

Radiation induced mutants in elite genetic background for the augmentation of genetic diversity

International Nuclear Information System (INIS)

Kumar, V.; Bhagwat, S.G.

2011-01-01

Rice (Oryza sativa L.), an important food crop for India, shows large genetic diversity. However, despite the large genetic resource, high genetic similarity is reported in cultivated varieties indicating genetic erosion. Radiation induced mutations provide genetic variability in elite background. In the present study, twenty gamma ray induced mutants of rice variety WL112 (carrying sd-1 semi-dwarfing gene) were analysed for genetic diversity using microsatellite markers. The high range of genetic diversity among mutants indicated that the mutants possess potential for enhancing variability in rice. Cluster analysis showed presence of five clusters having small sub-clusters. Earliness, semi-dwarf stature or resistance to blast disease observed among the mutants showed that these will be useful in breeding programmes. (author)

Ultralow background germanium gamma-ray spectrometer using superclean materials and cosmic-ray anticoincidence

International Nuclear Information System (INIS)

Reeves, J.H.; Hensley, W.K.; Brodzinski, R.L.; Ryge, P.

1983-10-01

Efforts to measure the double beta decay of 76 Ge as predicted by Grand Unified Theories have resulted in the development of a high resolution germanium diode gamma-ray spectrometer with an exceptionally low background. This paper describes the development of this system and how these techniques can be utilized to significantly reduce the background in high resolution photon spectrometers at only a moderate cost

Can Winds Driven by Active Galactic Nuclei Account for the Extragalactic Gamma-Ray and Neutrino Backgrounds?

Science.gov (United States)

Liu, Ruo-Yu; Murase, Kohta; Inoue, Susumu; Ge, Chong; Wang, Xiang-Yu

2018-05-01

Various observations are revealing the widespread occurrence of fast and powerful winds in active galactic nuclei (AGNs) that are distinct from relativistic jets, likely launched from accretion disks and interacting strongly with the gas of their host galaxies. During the interaction, strong shocks are expected to form that can accelerate nonthermal particles to high energies. Such winds have been suggested to be responsible for a large fraction of the observed extragalactic gamma-ray background (EGB) and the diffuse neutrino background, via the decay of neutral and charged pions generated in inelastic pp collisions between protons accelerated by the forward shock and the ambient gas. However, previous studies did not properly account for processes such as adiabatic losses that may reduce the gamma-ray and neutrino fluxes significantly. We evaluate the production of gamma rays and neutrinos by AGN-driven winds in detail by modeling their hydrodynamic and thermal evolution, including the effects of their two-temperature structure. We find that they can only account for less than ∼30% of the EGB flux, as otherwise the model would violate the independent upper limit derived from the diffuse isotropic gamma-ray background. If the neutrino spectral index is steep with Γ ≳ 2.2, a severe tension with the isotropic gamma-ray background would arise as long as the winds contribute more than 20% of the IceCube neutrino flux in the 10–100 TeV range. At energies ≳ 100 TeV, we find that the IceCube neutrino flux may still be accountable by AGN-driven winds if the spectral index is as small as Γ ∼ 2.0–2.1.

Sensitivity to Antibiotics of Bacteria Exposed to Gamma Radiation Emitted from Hot Soils of the High Background Radiation Areas of Ramsar, Northern Iran

Directory of Open Access Journals (Sweden)

Seyed Mohammad Javad Mortazavi

2017-04-01

Full Text Available Background: Over the past several years our laboratories have investigated different aspects of the challenging issue of the alterations in bacterial susceptibility to antibiotics induced by physical stresses. Objective: To explore the bacterial susceptibility to antibiotics in samples of Salmonella enterica subsp. enterica serovar Typhimurium (S. typhimurium, Staphylococcus aureus, and Klebsiella pneumoniae after exposure to gamma radiation emitted from the soil samples taken from the high background radiation areas of Ramsar, northern Iran. Methods: Standard Kirby-Bauer test, which evaluates the size of the zone of inhibition as an indicator of the susceptibility of different bacteria to antibiotics, was used in this study. Results: The maximum alteration of the diameter of inhibition zone was found for K. pneumoniae when tested for ciprofloxacin. In this case, the mean diameter of no growth zone in non-irradiated control samples of K. pneumoniae was 20.3 (SD 0.6 mm; it was 14.7 (SD 0.6 mm in irradiated samples. On the other hand, the minimum changes in the diameter of inhibition zone were found for S. typhimurium and S. aureus when these bacteria were tested for nitrofurantoin and cephalexin, respectively. Conclusion: Gamma rays were capable of making significant alterations in bacterial susceptibility to antibiotics. It can be hypothesized that high levels of natural background radiation can induce adaptive phenomena that help microorganisms better cope with lethal effects of antibiotics.

Distribution characteristics of natural gamma background levels around the capital city Shillong, Meghalaya (India)

International Nuclear Information System (INIS)

Kukreti, B.M.; Sharma, G.K.; Rao, M.S.; Ramabhadraih, T.; Bhaskar Rao, Arjun; Bhuphang, A.

2012-01-01

Onsite measurement of natural gamma radiation around the capital city Shillong in Meghalaya, has been carried out using GPS device and environmental survey meter. Each referenced insitu data point was validated at the site by means of simultaneous measurements of radiation levels (at 1.0 mts height) through handheld dosimeters. Collected data points on natural background levels, have been analysed and quantified in the context of preparing reference background levels in the city in order to deal with any radiological emergency that may arise in the public domain. Study reveals Gaussian distributed mean annual gamma dose of 0.77 mSv (n=53) in the range of 0.38 to 1.51 mSv. The study area, bound by the coordinates N (25.50°-25.66°, and E (91.82°-91.96°) indicates few pockets of higher average background levels, particularly towards the eastern side of study area, namely Nongmynsong, NEIGRIMS and Happy Valley. However, from the radiological safety aspects in public domain, all these reported levels are within the safety limits of prevailing environmental background. (author)

Quantitative estimations of the efficiency of stabilization and lowering of background in gamma-spectrometry of environment samples

International Nuclear Information System (INIS)

Pop, O.M.; Stets, M.V.; Maslyuk, V.T.

2015-01-01

We consider a gamma-spectrometric complex of IEP of the NAS of Ukraine, where a passive multilayer external defense is used (complex has been made in 1989). We have developed and investigated a system of stability and lowering of background in the gamma-spectrometric complex. As metrological coefficients, the efficiency factor of defense are considered, the calculation and analysis of which show that their values are different for different energies of gamma-quanta and gamma-active nuclides

Assessment of background gamma radiation and determination of excess lifetime cancer risk in Sabzevar City, Iran in 2014

Directory of Open Access Journals (Sweden)

Akbar Eslami

2016-01-01

Full Text Available Background: Background gamma radiation levels vary in different locations and depended on many factors such as radiation properties of soil, building materials as well as construction types which human lives on it. People are always exposed to ionizing radiation, which could badly influence their health. The aim of this study was to evaluate the background gamma-ray dose rate and the estimated annual effective dose equivalent and determination of excess lifetime cancer risk in Sabzevar City, Iran. Methods: The aim of this cross-sectional study was to determine the dose rate of background gamma radiation in outdoor an indoor areas, 26 stations were selected using the map of the Sabzevar City. The amount of gamma radiation was measured at 4 months (September to January in 2014 year. The dosimeter used in this study was a survey meter, that is designed for monitoring radiation of x, gamma and beta rays. Results: The obtained results show that there are significant differences between the indoor and outdoor exposures (P> 0.05. We did not observe significant differences between the time of sampling and sampling locations, (P<0.05. The minimum and maximum values of dose rate were found 66±20 nSvh-1 and 198±28 nSvh-1. The annual effective dose for Sabzevar residents was estimated to be 0.85 mSv and also the amount of excess lifetime cancer risk was estimated 3.39×10-3. Conclusion: According to the results, the excess lifetime cancer risk and the annual effective dose for the Sabzavar City residents due to the background gamma radiation was higher than the global average (0.5 mSv. The epidemiological studies have been proposed to evaluate the risk of chronic diseases associated with natural radiation exposure among residents.

Influence of climatological and meteorological events on the Cuban environmental gamma background

International Nuclear Information System (INIS)

Dominguez Ley, Orlando; Caveda Ramos, Celia; Ramos Viltre, Emma O.; Dominguez Garcia, Adriel; Alonso Abad, Dolores

2008-01-01

Full text: A network of environmental radiological surveillance can appropriately respond in case of any radiological anomaly, due to the suitable methodology employed, the equipment used, the automatized detection systems and the data processing. But it is also important to know how the measurements of the different radiological indicators vary with the action of any atmospheric phenomenon. In this work, an analysis of the effects produced on the environmental gamma background in Cuba when acting climatological and meteorological events, has been achieved. Events, such as seasons of severe precipitation, dry seasons, winter and summer, hurricanes and high and low pressures are studied. The measurements were carried out with a gamma probe which is equipped with two Geiger Muller detectors and a temperature sensor. This probe is located at the height of 3.5 m and is exposed to the direct sun rays. We have built hypothesis for explaining some behaviors related to meteorological events, such as hurricanes. However, our theories are not conclusive, since the data obtained from the presence of this kind of phenomena next to the sites of interest was very poor. In this work, we have given explanation to the fluctuation of the measurements achieved of the environmental gamma background, based on the occurrence of some meteorological and climatological events. All this was possible due to a previous study about the influence of the diurnal variation of the temperature over the measurements of the gamma dose rate. On the other hand, the results obtained and the study of the influence of another environmental parameters, will contribute to the alarm levels setting for this radiological indicator according to the season which the measurements are achieved in. (author)

Systematic Assessment of Neutron and Gamma Backgrounds Relevant to Operational Modeling and Detection Technology Implementation

Energy Technology Data Exchange (ETDEWEB)

Archer, Daniel E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hornback, Donald Eric [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Johnson, Jeffrey O. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Nicholson, Andrew D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Patton, Bruce W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Peplow, Douglas E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Miller, Thomas Martin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ayaz-Maierhafer, Birsen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2015-01-01

This report summarizes the findings of a two year effort to systematically assess neutron and gamma backgrounds relevant to operational modeling and detection technology implementation. The first year effort focused on reviewing the origins of background sources and their impact on measured rates in operational scenarios of interest. The second year has focused on the assessment of detector and algorithm performance as they pertain to operational requirements against the various background sources and background levels.

Peak-by-peak correction of Ge(Li) gamma-ray spectra for photopeaks from background

Energy Technology Data Exchange (ETDEWEB)

Cutshall, N H; Larsen, I L [Oak Ridge National Lab., TN (USA)

1980-12-01

Background photopeaks can interfere with accurate measurement of low levels of radionuclides by gamma-ray spectrometry. A flowchart for peak-by-peak correction of sample spectra to produce accurate results is presented.

Probing the Cosmic X-Ray and MeV Gamma-Ray Background Radiation through the Anisotropy

Energy Technology Data Exchange (ETDEWEB)

Inoue, Yoshiyuki [Stanford Univ., CA (United States). Kavli Inst. for Particle Astrophysics and Cosmology; SLAC National Accelerator Lab., Menlo Park, CA (United States); Murase, Kohta [Inst. for Advanced Study, Princeton, NJ (United States). School of Natural Sciences; Madejski, Grzegorz M. [Stanford Univ., CA (United States). Kavli Inst. for Particle Astrophysics and Cosmology; SLAC National Accelerator Lab., Menlo Park, CA (United States); Uchiyama, Yasunobu [Stanford Univ., CA (United States). Kavli Inst. for Particle Astrophysics and Cosmology; SLAC National Accelerator Lab., Menlo Park, CA (United States); Rikkyo Univ., Tokyo (Japan). Dept. of Physics

2013-09-24

While the cosmic soft X-ray background is very likely to originate from individual Seyfert galaxies, the origin of the cosmic hard X-ray and MeV gamma-ray background is not fully understood. It is expected that Seyferts including Compton thick population may explain the cosmic hard X-ray background. At MeV energy range, Seyferts having non-thermal electrons in coronae above accretion disks or MeV blazars may explain the background radiation. We propose that future measurements of the angular power spectra of anisotropy of the cosmic X-ray and MeV gamma-ray backgrounds will be key to deciphering these backgrounds and the evolution of active galactic nuclei (AGNs). As AGNs trace the cosmic large-scale structure, spatial clustering of AGNs exists. We show that e-ROSITA will clearly detect the correlation signal of unresolved Seyferts at 0.5-2 keV and 2-10 keV bands and will be able to measure the bias parameter of AGNs at both bands. Once the future hard X-ray all sky satellites achieve the sensitivity better than 10^-12 erg/cm²/s^-1 at 10-30 keV or 30-50 keV - although this is beyond the sensitivities of current hard X-ray all sky monitors - angular power spectra will allow us to independently investigate the fraction of Compton-thick AGNs in all Seyferts. We also find that the expected angular power spectra of Seyferts and blazars in the MeV range are different by about an order of magnitude, where the Poisson term, so-called shot noise, is dominant. Current and future MeV instruments will clearly disentangle the origin of the MeV gamma-ray background through the angular power spectrum.

Probing the cosmic x-ray and MeV gamma ray background radiation through the anisotropy

Energy Technology Data Exchange (ETDEWEB)

Inoue, Yoshiyuki [Stanford Univ., CA (United States); Murase, Kohta [Inst. for Advanced Study, Princeton, NJ (United States); Madejski, Grzegorz M. [Stanford Univ., CA (United States); Uchiyama, Yasunobu [Stanford Univ., CA (United States); Rikkyo Univ., Tokyo (Japan)

2013-09-24

While the cosmic soft X-ray background is very likely to originate from individual Seyfert galaxies, the origin of the cosmic hard X-ray and MeV gamma-ray background is not fully understood. It is expected that Seyferts including Compton thick population may explain the cosmic hard X-ray background. At MeV energy range, Seyferts having non-thermal electrons in coronae above accretion disks or MeV blazars may explain the background radiation. We propose that future measurements of the angular power spectra of anisotropy of the cosmic X-ray and MeV gamma-ray backgrounds will be key to deciphering these backgrounds and the evolution of active galactic nuclei (AGNs). As AGNs trace the cosmic large-scale structure, spatial clustering of AGNs exists. We show that e-ROSITA will clearly detect the correlation signal of unresolved Seyferts at 0.5-2 keV and 2-10 keV bands and will be able to measure the bias parameter of AGNs at both bands. Once future hard X-ray all sky satellites achieve a sensitivity better than 10–12 erg cm–2 s–1 at 10-30 keV or 30-50 keV—although this is beyond the sensitivities of current hard X-ray all sky monitors—angular power spectra will allow us to independently investigate the fraction of Compton-thick AGNs in all Seyferts. We also find that the expected angular power spectra of Seyferts and blazars in the MeV range are different by about an order of magnitude, where the Poisson term, so-called shot noise, is dominant. Current and future MeV instruments will clearly disentangle the origin of the MeV gamma-ray background through the angular power spectrum.

Measurement of gamma natural background radiation at Chamaraja Nagar, Karnataka state, India

International Nuclear Information System (INIS)

Nagaraju, K.M.; Chandrashekara, M.S.; Paramesh, L.

2012-01-01

The radioactive elements and their radiation are ubiquitous in the environment. The Influence of radiation on living organisms is imminent and very important to study. The ocean, the mountains, the air, and our food all expose us to small amounts of natural background radiation. Cosmic rays from outer space are another large contributor of natural background radiation. Much of the earth's natural background radiation is in the form of gamma radiation, a part of which comes from outer space. Some part of cosmic ray is filtered out by the presence of earth's atmosphere, so there are natural controls for the amount of radiation that people receive. The amount of radiation received by an individual depends on altitude, latitude type of building and the building construction materials. In the present study, measurements of natural background radiation were made in the temples, schools, dwellings, and hill stations in Chamaraja Nagar area, Karnataka state, India by using environmental dosimeter technique. The results show that, absorbed dose rate of background radiations at inside schools varies from 93.96 to 120.93 nGyh -1 with a standard deviation of 10.62 nGyh -1 and outside schools it varies from 60.9 to 113.1 nGyh -1 with a standard deviation of 15.1 nGyh -1 . In temples, the absorbed dose rate varies from 104.4 to 244.91 nGyh - 1 with a standard deviation of 48.34 nGyh -1 and outside the temples it varies from 87.9 to 176.61 nGyh -1 with a standard deviation of 30.896 nGyh -1 . The absorbed dose rate of background radiations at dwellings in indoor varies from 94.0 to 139.2 nGyh -1 with a standard deviation of 16.6 nGyh -1 and in outdoor it varies from 60.9 to 118.32 nGyh -1 with a standard deviation of 19.41 nGyh -1 . The measurements were also carried out in dwellings on hill stations in Chamaraja Nagar district. Indoor gamma dose rate varies from 103.53 to 236.64 nGyh -1 with a standard deviation of 59.8 nGyh -1 and outdoor gamma dose rate varies from 78.3 to 119

The Study of Radiation of Gamma-Ray Background at Sedimentology Laboratorium, P3TIR, BATAN, Using Gamma Spectrometry

International Nuclear Information System (INIS)

Lubis, Ali Arman; Aliyanta, Barokah; Darman

2002-01-01

The measurement of background radiation of gamma-ray has been done at Sedimentology Laboratory, SDAL building, P3TIR, BATAN using gamma spectrometer. The measurement was done without shielding with the range of energy between 50 keV and 1500 keV. The identified radiations are coming from environmental radionuclide and man-made radionuclide as well with 32 energy peaks. The environmental radionuclides are from Uranium series, Thorium series, and 4 0 K having dose rate of 12.510 ± O.980, 36.408 ± 3.243, 9.455 ±O.016 n Sv/day, respectively, whilst man-made radionuclide is 6 O C o having dose rate of O.136 ±O.078 n Sv/day

Induced disease resistance of satsuma mandarings against penicillium digitatum by gamma irradiation

International Nuclear Information System (INIS)

Jeong, Rae Dong

2017-01-01

Gamma irradiation, which is a type of ionizing radiation, can be used as a fruit inducible factor. In the present study, the effects of gamma irradiation on the resistance of mandarin fruits against Penicillium digitatum, the causal agent of postharvest green mold disease, were investigated. Pretreatment of a low dose of gamma irradiation effectively reduced the disease incidence and lesion diameter of mandarin fruits inoculated with P. digatatum during storage for 14 d. Interestingly, exposed to 400 Gy of gamma irradiation significantly maintained firmness and stimulated the synthesis of defense-related enzymes, (e.g., β-1,3-glucanase, phenylalanine, peroxidase, and polyphenol oxidase) and pathogenesis-related (PR) genes (e.g., PR-1 and PR-2). Therefore, the gamma irradiation-induced resistance against P. digatatum involves both changes of phenolic compounds and the induction of expression of defense-related genes. In addition, scanning electron microscopy analysis revealed that induced disease resistance by gamma irradiation signifcantly inhibits the growth of P. digatatum in mandarin fruits. These results suggest that the exposure of gamma irradiation is a potential methods for inducing the disease resistance of fruit to postharvest fungal pathogens and for extending the postharvest life of mandarin fruit

Induced disease resistance of satsuma mandarings against penicillium digitatum by gamma irradiation

Energy Technology Data Exchange (ETDEWEB)

Jeong, Rae Dong [Dept. of Applied Biology, Institute of Environmentally Friendly Agriculture, Chonnam National University, Gwangju (Korea, Republic of)

2017-06-15

Gamma irradiation, which is a type of ionizing radiation, can be used as a fruit inducible factor. In the present study, the effects of gamma irradiation on the resistance of mandarin fruits against Penicillium digitatum, the causal agent of postharvest green mold disease, were investigated. Pretreatment of a low dose of gamma irradiation effectively reduced the disease incidence and lesion diameter of mandarin fruits inoculated with P. digatatum during storage for 14 d. Interestingly, exposed to 400 Gy of gamma irradiation significantly maintained firmness and stimulated the synthesis of defense-related enzymes, (e.g., β-1,3-glucanase, phenylalanine, peroxidase, and polyphenol oxidase) and pathogenesis-related (PR) genes (e.g., PR-1 and PR-2). Therefore, the gamma irradiation-induced resistance against P. digatatum involves both changes of phenolic compounds and the induction of expression of defense-related genes. In addition, scanning electron microscopy analysis revealed that induced disease resistance by gamma irradiation signifcantly inhibits the growth of P. digatatum in mandarin fruits. These results suggest that the exposure of gamma irradiation is a potential methods for inducing the disease resistance of fruit to postharvest fungal pathogens and for extending the postharvest life of mandarin fruit.

Peak-by-peak correction of Ge(Li) gamma-ray spectra for photopeaks from background

International Nuclear Information System (INIS)

Cutshall, N.H.; Larsen, I.L.

1980-01-01

Background photopeaks can interfere with accurate measurement of low levels of radionuclides by gamma-ray spectrometry. A flowchart for peak-by-peak correction of sample spectra to produce accurate results is presented. (orig.)

Probing the Extragalactic Cosmic-Ray Origin with Gamma-Ray and Neutrino Backgrounds

Energy Technology Data Exchange (ETDEWEB)

Globus, Noemie; Piran, Tsvi [Racah Institute of Physics, The Hebrew University, 91904 Jerusalem (Israel); Allard, Denis; Parizot, Etienne [Laboratoire Astroparticule et Cosmologie, Université Paris Diderot/CNRS, 10 rue A. Domon et L. Duquet, F-75205 Paris Cedex 13 (France)

2017-04-20

GeV–TeV gamma-rays and PeV–EeV neutrino backgrounds provide a unique window on the nature of the ultra-high-energy cosmic rays (UHECRs). We discuss the implications of the recent Fermi -LAT data regarding the extragalactic gamma-ray background and related estimates of the contribution of point sources as well as IceCube neutrino data on the origin of the UHECRs. We calculate the diffuse flux of cosmogenic γ -rays and neutrinos produced by the UHECRs and derive constraints on the possible cosmological evolution of UHECR sources. In particular, we show that the mixed-composition scenario considered in Globus et al., which is in agreement with both (i) Auger measurements of the energy spectrum and composition up to the highest energies and (ii) the ankle-like feature in the light component detected by KASCADE-Grande, is compatible with both the Fermi -LAT measurements and with current IceCube limits. We also discuss the possibility for future experiments to detect associated cosmogenic neutrinos and further constrain the UHECR models, including possible subdominant UHECR proton sources.

The measurement of gamma ray induced heating in a mixed neutron and gamma ray environment

International Nuclear Information System (INIS)

Chiu, H.K.

1991-10-01

The problem of measuring the gamma heating in a mixed DT neutron and gamma ray environment was explored. A new detector technique was developed to make this measurement. Gamma heating measurements were made in a low-Z assembly irradiated with 14-Mev neutrons and (n, n') gammas produced by a Texas Nuclear Model 9400 neutron generator. Heating measurements were made in the mid-line of the lattice using a proportional counter operating in the Continuously-varied Bias-voltage Acquisition mode. The neutron-induced signal was separated from the gamma-induced signal by exploiting the signal rise-time differences inherent to radiations of different linear energy transfer coefficient, which are observable in a proportional counter. The operating limits of this measurement technique were explored by varying the counter position in the low-Z lattice, hence changing the irradiation spectrum observed. The experiment was modelled numerically to help interpret the measured results. The transport of neutrons and gamma rays in the assembly was modelled using the one- dimensional radiation transport code ANISN/PC. The cross-section set used for these calculations was derived from the ENDF/B-V library using the code MC 2 -2 for the case of DT neutrons slowing down in a low-Z material. The calculated neutron and gamma spectra in the slab and the relevant mass-stopping powers were used to construct weighting factors which relate the energy deposition in the counter fill-gas to that in the counter wall and in the surrounding material. The gamma energy deposition at various positions in the lattice is estimated by applying these weighting factors to the measured gamma energy deposition in the counter at those locations

Differential expression of interferon-gamma and interferon-gamma-inducing cytokines in Thai patients with scrub typhus or leptospirosis

NARCIS (Netherlands)

Chierakul, Wirongrong; de Fost, Maaike; Suputtamongkol, Yupin; Limpaiboon, Roongreung; Dondorp, Arjen; White, Nicholas J.; van der Poll, Tom

2004-01-01

Interferon (IFN)-gamma plays an important role in the induction of a type 1 immune response against intracellular pathogens. We compared the plasma levels of IFN-gamma and IFN-gamma-inducing cytokines in adult Thai patients with scrub typhus, caused by the obligate intracellular bacterium Orientia

Interferon gamma, interferon-gamma-induced-protein 10, and tuberculin responses of children at high risk of tuberculosis infection

DEFF Research Database (Denmark)

Petrucci, Roberta; Abu Amer, Nabil; Gurgel, Ricardo Queiroz

2008-01-01

BACKGROUND: Children in contact with adults with pulmonary tuberculosis (TB) are at risk for infection and disease progression, and chemoprophylaxis may reduce this risk. The identification of infection is based on the tuberculin skin test (TST) and interferon-gamma (INF-gamma) release assays...

Plutonium characterisation with prompt high energy gamma-rays from (n,gamma) reactions for nuclear warhead dismantlement verification

Energy Technology Data Exchange (ETDEWEB)

Postelt, Frederik; Gerald, Kirchner [Carl Friedrich von Weizsaecker-Centre for Science and Peace Research, Hamburg (Germany)

2015-07-01

Measurements of neutron induced gammas allow the characterisation of fissile material (i.e. plutonium and uranium), despite self- and additional shielding. Most prompt gamma-rays from radiative neutron capture reactions in fissile material have energies between 3 and 6.5 MeV. Such high energy photons have a high penetrability and therefore minimise shielding and self-absorption effects. They are also isotope specific and therefore well suited to determine the isotopic composition of fissile material. As they are non-destructive, their application in dismantlement verification is desirable. Disadvantages are low detector efficiencies at high gamma energies, as well as a high background of gammas which result from induced fission reactions in the fissile material, as well as delayed gammas from both, (n,f) and(n,gamma) reactions. In this talk, simulations of (n,gamma) measurements and their implications are presented. Their potential for characterising fissile material is assessed and open questions are addressed.

Interferon gamma, interferon-gamma-induced-protein 10, and tuberculin responses of children at high risk of tuberculosis infection

DEFF Research Database (Denmark)

Petrucci, Roberta; Abu Amer, Nabil; Gurgel, Ricardo Queiroz

2008-01-01

BACKGROUND: Children in contact with adults with pulmonary tuberculosis (TB) are at risk for infection and disease progression, and chemoprophylaxis may reduce this risk. The identification of infection is based on the tuberculin skin test (TST) and interferon-gamma (INF-gamma) release assays. Ot...

Anisotropies in the diffuse gamma-ray background measured by the Fermi-LAT

Energy Technology Data Exchange (ETDEWEB)

Cuoco, A. [Stockholm University-Oskar Klein Center AlbaNova University Center, Fysikum, SE-10691 Stockholm (Sweden); Linden, T. [Department of Physics, University of California, Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States); Mazziotta, M.N. [Istituto Nazionale di Fisica Nucleare, Sezione di Bari, 70126 Bari (Italy); Siegal-Gaskins, J.M. [Einstein Postdoctoral Fellow, California Institute of Technology 1200 E. California Blvd., Pasadena, CA 91125 (United States); Vitale, Vincenzo, E-mail: vincenzo.vitale@roma2.infn.it [Istituto Nazionale di Fisica Nucleare, Sezione di Tor Vergata, 00133 Roma (Italy); Komatsu, E. [Texas Cosmology Center and Department of Astronomy, University of Texas, Austin, Dept. of Astronomy, 2511 Speedway, Austin, TX 78712 (United States)

2012-11-11

The small angular scale fluctuations of the (on large scale) isotropic gamma-ray background (IGRB) carry information about the presence of unresolved source classes. A guaranteed contribution to the IGRB is expected from the unresolved gamma-ray AGN while other extragalactic sources, Galactic gamma-ray source populations and dark matter Galactic and extragalactic structures (and sub-structures) are candidate contributors. The IGRB was measured with unprecedented precision by the Large Area Telescope (LAT) on-board of the Fermi gamma-ray observatory, and these data were used for measuring the IGRB angular power spectrum (APS). Detailed Monte Carlo simulations of Fermi-LAT all-sky observations were performed to provide a reference against which to compare the results obtained for the real data set. The Monte Carlo simulations are also a method for performing those detailed studies of the APS contributions of single source populations, which are required in order to identify the actual IGRB contributors. We present preliminary results of an anisotropy search in the IGRB. At angular scales <2 Degree-Sign (e.g., above multipole 155), angular power above the photon noise level is detected, at energies between 1 and 10 GeV in each energy bin, with statistical significance between 7.2 and 4.1{sigma}. The obtained energy dependences point to the presence of one or more unclustered source populations with the components having an average photon index {Gamma}=2.40{+-}0.07.

Characterization of the InSTEC's low-background gamma spectrometer for environmental radioactivity studies

International Nuclear Information System (INIS)

Diaz Rizo, O.; Lopez Pino, N.; D'Alessandro Rodriguez, K.; Reyes, H.; Padilla Cabal, F.; Arado Lopez, J.O.; Casanova Diaz, A.O.; Gelen Rudnikas, A.; Rodenas Palomino, C.; Gomez Arozamena, J.

2010-01-01

The capabilities of the Low-Background Gamma Spectrometer (LBGS) at InSTEC were studied for environmental purposes. Fifty three γ-lines were identified in the LBGS background spectrum. The Minimum Detectable Activity for 2 10 Pb, 2 38 U, 2 26 Ra, 1 37 Cs, 2 32 Th and 4 0K were calculated using the detector's volumetric efficiency simulated by the Monte Carlo method. Validation was performed by absolute and relative analysis of radionuclide activities present in a marine sediment certified material. (author)

Energies and Yields of Prompt Gamma Rays from Fragments in Slow-Neutron Induced Fission of 235U

Energy Technology Data Exchange (ETDEWEB)

Albinsson, H [Chalmers Univ. of Technology, Goeteborg (SE)

1971-04-15

Measurements were made on the gamma radiation emitted from fission fragments in slow-neutron induced fission of 235U. The fragments were detected with solid state detectors of the surface barrier type and the gamma radiation with a Nal(Tl) scintillator. Mass selection was used so that the gamma radiation could be measured as a function of fragment mass. Time discrimination between the fission gammas and the prompt neutrons released in the fission process was employed to reduce the background. The gamma radiation emitted during different time intervals after the fission event was studied with the help of a collimator, the position of which was changed along the path of the fission fragments. In this way it was possible to select various collimator settings and let gamma radiation of different half-lives be enhanced. Gamma-ray energy spectra from these time components were then recorded as function of mass. The spectrum shape differed greatly depending on the half-life of the radiation and the fragment from which it was emitted. The results of the present measurements were discussed in the light of existing fission models, and comparisons were made with prompt gamma-ray and neutron data from other fission experiments

Energies and Yields of Prompt Gamma Rays from Fragments in Slow-Neutron Induced Fission of 235U

International Nuclear Information System (INIS)

Albinsson, H.

1971-04-01

Measurements were made on the gamma radiation emitted from fission fragments in slow-neutron induced fission of 235 U. The fragments were detected with solid state detectors of the surface barrier type and the gamma radiation with a Nal(Tl) scintillator. Mass selection was used so that the gamma radiation could be measured as a function of fragment mass. Time discrimination between the fission gammas and the prompt neutrons released in the fission process was employed to reduce the background. The gamma radiation emitted during different time intervals after the fission event was studied with the help of a collimator, the position of which was changed along the path of the fission fragments. In this way it was possible to select various collimator settings and let gamma radiation of different half-lives be enhanced. Gamma-ray energy spectra from these time components were then recorded as function of mass. The spectrum shape differed greatly depending on the half-life of the radiation and the fragment from which it was emitted. The results of the present measurements were discussed in the light of existing fission models, and comparisons were made with prompt gamma-ray and neutron data from other fission experiments

Characterization of the InSTEC's low-background gamma spectrometer for environmental radioactivity studies

International Nuclear Information System (INIS)

Diaz Rizo, O.; Lopez Pino, N.; D'Alessandro Rodriguez, K.; Reyes, H.; Padilla Cabal, F.; Arado Lopez, J.O.; Casanova Diaz, A.O.; Gelen Rudnikas, A.; Rodenas Palomino, C.; Gomez Arozamena, J.

2009-01-01

The capabilities of the Low-Background Gamma Spectrometer (LBGS) at InSTEC were studied for environmental purposes. Fifty three ?-lines were fixed/identified? in the LBGS background spectrum. The Minimum Detectable Activity for 2 10 Pb, 2 38 U, 2 26 Ra, 1 37 Cs, 2 32 Th and 4 0K were calculated using the detector's volumetric efficiency simulated by the Monte Carlo method. The radionuclide activities in a marine sediment standard reference material? were determined by absolute and relative methods for validation./¿absolute and relative validation? (author)

Prevention Effect of Poly-Gamma-Glutamic Acid on Tissue Damage Induced by Gamma Irradiation as a Natural Cross-Linker

Energy Technology Data Exchange (ETDEWEB)

Kim, Jaehun; Sung, Nakyun; Kim, Jeongsoo; Jo, Euri; Choi, Jongil; Park, Jongheum; Lee, Juwoon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, Kwangwon [Eulji Univ. Hospital, Daejeon (Korea, Republic of); Kwon, Jungkee [Chonbuk National Univ., Jeonju (Korea, Republic of); Kim, Taewoon [Jeonbuk Technopark, Jeonju (Korea, Republic of)

2012-03-15

This study was to determine the prevention effect of poly-gamma-glutamic acid (PGA) on tissue damage induced by gamma irradiation for development of xenograft. PGA (MW 2000 kDa) extracted from permeated soy bean (natto) was used in this study as natural compound, and glutaraldehyde (GA) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) were used as a control, chemical based cross-linking agents. GA, EDC and PGA treated porcine tendons were gamma-irradiated at the dose of 30 kGy. Prevention effects against tissue damage were measured as the result of tensile strength, hydroxyproline contents and tissue morphological analysis. Tensile of porcine tendon was remarkably decreased by gamma irradiation, but increased in PGA treated group. Morphological analysis showed that collagen structure was broken by gamma irradiation, but attenuated by PGA treatment. Base on the results, it demonstrated that gamma irradiation can induce severe alteration of porcine tendon, but PGA can effectively improve the tissue damage.

Prevention Effect of Poly-Gamma-Glutamic Acid on Tissue Damage Induced by Gamma Irradiation as a Natural Cross-Linker

International Nuclear Information System (INIS)

Kim, Jaehun; Sung, Nakyun; Kim, Jeongsoo; Jo, Euri; Choi, Jongil; Park, Jongheum; Lee, Juwoon; Lee, Kwangwon; Kwon, Jungkee; Kim, Taewoon

2012-01-01

This study was to determine the prevention effect of poly-gamma-glutamic acid (PGA) on tissue damage induced by gamma irradiation for development of xenograft. PGA (MW 2000 kDa) extracted from permeated soy bean (natto) was used in this study as natural compound, and glutaraldehyde (GA) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) were used as a control, chemical based cross-linking agents. GA, EDC and PGA treated porcine tendons were gamma-irradiated at the dose of 30 kGy. Prevention effects against tissue damage were measured as the result of tensile strength, hydroxyproline contents and tissue morphological analysis. Tensile of porcine tendon was remarkably decreased by gamma irradiation, but increased in PGA treated group. Morphological analysis showed that collagen structure was broken by gamma irradiation, but attenuated by PGA treatment. Base on the results, it demonstrated that gamma irradiation can induce severe alteration of porcine tendon, but PGA can effectively improve the tissue damage

Sensitivity to Antibiotics of Bacteria Exposed to Gamma Radiation Emitted from Hot Soils of the High Background Radiation Areas of Ramsar, Northern Iran.

Science.gov (United States)

Mortazavi, Seyed Mohammad Javad; Zarei, Samira; Taheri, Mohammad; Tajbakhsh, Saeed; Mortazavi, Seyed Alireza; Ranjbar, Sahar; Momeni, Fatemeh; Masoomi, Samaneh; Ansari, Leila; Movahedi, Mohammad Mehdi; Taeb, Shahram; Zarei, Sina; Haghani, Masood

2017-04-01

Over the past several years our laboratories have investigated different aspects of the challenging issue of the alterations in bacterial susceptibility to antibiotics induced by physical stresses. To explore the bacterial susceptibility to antibiotics in samples of Salmonella enterica subsp. enterica serovar Typhimurium ( S. typhimurium ), Staphylococcus aureus , and Klebsiella pneumoniae after exposure to gamma radiation emitted from the soil samples taken from the high background radiation areas of Ramsar, northern Iran. Standard Kirby-Bauer test, which evaluates the size of the zone of inhibition as an indicator of the susceptibility of different bacteria to antibiotics, was used in this study. The maximum alteration of the diameter of inhibition zone was found for K. pneumoniae when tested for ciprofloxacin. In this case, the mean diameter of no growth zone in non-irradiated control samples of K. pneumoniae was 20.3 (SD 0.6) mm; it was 14.7 (SD 0.6) mm in irradiated samples. On the other hand, the minimum changes in the diameter of inhibition zone were found for S. typhimurium and S. aureus when these bacteria were tested for nitrofurantoin and cephalexin, respectively. Gamma rays were capable of making significant alterations in bacterial susceptibility to antibiotics. It can be hypothesized that high levels of natural background radiation can induce adaptive phenomena that help microorganisms better cope with lethal effects of antibiotics.

Dark matter implications of Fermi-LAT measurement of anisotropies in the diffuse gamma-ray background

International Nuclear Information System (INIS)

Gómez-Vargas, G.A.; Cuoco, A.; Linden, T.; Sánchez-Conde, M.A.; Siegal-Gaskins, J.M.; Delahaye, T.; Fornasa, M.; Komatsu, E.

2014-01-01

The detailed origin of the diffuse gamma-ray background is still unknown. However, the contribution of unresolved sources is expected to induce small-scale anisotropies in this emission, which may provide a way to identify and constrain the properties of its contributors. Recent studies have predicted the contributions to the angular power spectrum (APS) from extragalactic and galactic dark matter (DM) annihilation or decay. The Fermi-LAT collaboration reported detection of angular power with a significance larger than 3σ in the energy range from 1 GeV to 10 GeV on 22 months of data (Ackermann et al., 2012 [2]). For these preliminary results the already published Fermi-LAT APS measurements (Ackermann et al., 2012 [2]) are compared to the accurate predictions for DM anisotropies from state-of-the-art cosmological simulations as presented in Fornasa et al. (2013) [1] to derive constraints on different DM candidates

Dark matter implications of Fermi-LAT measurement of anisotropies in the diffuse gamma-ray background

Energy Technology Data Exchange (ETDEWEB)

Gómez-Vargas, G.A., E-mail: germanarturo.gomez@uam.es [Departamento de Física Teórica, Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid (Spain); Instituto de Física Teórica IFT-UAM/CSIC, Universidad Autónoma de Madrid, Cantoblanco, E-28049, Madrid (Spain); Istituto Nazionale di Fisica Nucleare, Sez. Roma Tor Vergata, Roma (Italy); Cuoco, A. [The Oskar Klein Centre for Cosmo Particle Physics, AlbaNova, SE-106 91 Stockholm (Sweden); Linden, T. [Department of Physics, University of California, Santa Cruz, CA 95064 (United States); Sánchez-Conde, M.A. [SLAC National Accelerator Laboratory and Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, CA 94025 (United States); Siegal-Gaskins, J.M. [California Institute of Technology, Pasadena, CA 91125 (United States); Delahaye, T. [LAPTh, Universit e de Savoie, CNRS, 9 chemin de Bellevue, BP110, F-74941 Annecy-le-Vieux Cedex (France); Institut d' Astrophysique de Paris, UMR 7095 – CNRS, Universit e Pierre and Marie Curie, 98 bis boulevard Arago, 75014 Paris (France); Instituto de Física Teórica IFT-UAM/CSIC, Universidad Autónoma de Madrid, Cantoblanco, E-28049, Madrid (Spain); Fornasa, M. [School of Physics and Astronomy, University of Nottingham, NG7 2RD Nottingham (United Kingdom); Komatsu, E. [Max-Planck-Institut fur Astrophysik, Karl-Schwarzschild Str. 1, 85741 Garching (Germany); Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU, WPI), Todai Institutes for Advanced Study, the University of Tokyo, Kashiwa 277-8583 (Japan); Texas Cosmology Center and the Department of Astronomy, The University of Texas at Austin, 1 University Station, C1400, Austin, TX 78712 (United States); and others

2014-04-01

The detailed origin of the diffuse gamma-ray background is still unknown. However, the contribution of unresolved sources is expected to induce small-scale anisotropies in this emission, which may provide a way to identify and constrain the properties of its contributors. Recent studies have predicted the contributions to the angular power spectrum (APS) from extragalactic and galactic dark matter (DM) annihilation or decay. The Fermi-LAT collaboration reported detection of angular power with a significance larger than 3σ in the energy range from 1 GeV to 10 GeV on 22 months of data (Ackermann et al., 2012 [2]). For these preliminary results the already published Fermi-LAT APS measurements (Ackermann et al., 2012 [2]) are compared to the accurate predictions for DM anisotropies from state-of-the-art cosmological simulations as presented in Fornasa et al. (2013) [1] to derive constraints on different DM candidates.

BGSUB and BGFIX: FORTRAN programs to correct Ge(Li) gamma-ray spectra for photopeaks from radionuclides in background

International Nuclear Information System (INIS)

Cutshall, N.H.; Larsen, I.L.

1980-03-01

Two FORTRAN programs which provide correction and error analysis for background photopeak contributions to low-level gamma-ray spectra are discussed. A peak-by-peak background subtraction approach is used instead of channel-by-channel correction. The accuracy of corrected results near background levels is substantially improved over uncorrected values

On estimating the background of remote sensing gamma-ray spectroscopic data

Energy Technology Data Exchange (ETDEWEB)

Zhu, Meng-Hua, E-mail: mhzhu@must.edu.mo

2016-10-01

In this paper, we considered the inverse count accumulation process of gamma-ray spectrum and derived an iterative filtering method to estimate the background of noisy spectroscopic data for the remote sensing observations of planetary surface. Compared with the SNIP method, the proposed method avoids the calculation of the average FWHM of the whole spectrum or the peak regions, which is an important parameter for the SNIP method. The synthetic and experimental spectra are used to validate the derived method. The results show that the proposed method can estimate the background efficiently, especially for the spectroscopic data with Compton continuum. In addition, by combining the proposed method and the SNIP method, the average FWHM can be determined easily, which can be used to validate the characteristics of detector.

Contribution of 210Pb bremsstrahlung to the background of lead shielded gamma spectrometers

International Nuclear Information System (INIS)

Mrda, D.; Bikit, I.; Veskovic, M.; Forkapic, S.

2007-01-01

Lead, which is often used as a shielding material, contains 210 Pb (T 1/2 =22.3 y). The 46.54 keV γ-intensity of 210 Pb can be easily reduced by an inner lining, but the bremsstrahlung caused by the β-decay of its daughter, 210 Bi, with a maximal electron energy of 1.16 MeV, will contribute to the gamma detector background. The spectrum of this bremsstrahlung is calculated by numerically fitting the β-spectrum and integrating the Koch-Motz formula. The absorption of the bremsstrahlung in the lead and detection efficiencies for the HPGe detector are calculated by the effective solid angle algorithm, using corrections for the photopeak/Compton ratio of cross-sections in Ge. By comparison with the measured background spectrum, it is shown that, for the lead with 25 Bq/kg of 210 Pb up to 500 keV of gamma spectrum, the bremsstrahlung contribution to the background is about 20% for our surface-based detector system. Also, we compared our calculations with a Monte Carlo simulation of another detector system with a shield containing 1 Bq/kg of 210 Pb and found that our analytical method gives a value of roughly two times higher than the Monte Carlo one for the total bremsstrahlung contribution. The quality of the analytical semi-empirical method is proved by the reasonable agreement with the experimental results published

Guaranteed Unresolved Point Source Emission and the Gamma-ray Background

International Nuclear Information System (INIS)

Pavlidou, Vasiliki; Siegal-Gaskins, Jennifer M.; Brown, Carolyn; Fields, Brian D.; Olinto, Angela V.

2007-01-01

The large majority of EGRET point sources remain without an identified low-energy counterpart, and a large fraction of these sources are most likely extragalactic. Whatever the nature of the extragalactic EGRET unidentified sources, faint unresolved objects of the same class must have a contribution to the diffuse extragalactic gamma-ray background (EGRB). Understanding this component of the EGRB, along with other guaranteed contributions from known sources (blazars and normal galaxies), is essential if we are to use this emission to constrain exotic high-energy physics. Here, we follow an empirical approach to estimate whether the contribution of unresolved unidentified sources to the EGRB is likely to be important. Additionally, we discuss how upcoming GLAST observations of EGRET unidentified sources, their fainter counterparts, and the Galactic and extragalactic diffuse backgrounds, will shed light on the nature of the EGRET unidentified sources even without any positional association of such sources with low-energy counterparts

Aerosol and gamma background measurements at Basic Environmental Observatory Moussala

Directory of Open Access Journals (Sweden)

Angelov Christo

2016-03-01

Full Text Available Trans boundary and local pollution, global climate changes and cosmic rays are the main areas of research performed at the regional Global Atmospheric Watch (GAW station Moussala BEO (2925 m a.s.l., 42°10’45’’ N, 23°35’07’’ E. Real time measurements and observations are performed in the field of atmospheric chemistry and physics. Complex information about the aerosol is obtained by using a threewavelength integrating Nephelometer for measuring the scattering and backscattering coefficients, a continuous light absorption photometer and a scanning mobile particle sizer. The system for measuring radioactivity and heavy metals in aerosols allows us to monitor a large scale radioactive aerosol transport. The measurements of the gamma background and the gamma-rays spectrum in the air near Moussala peak are carried out in real time. The HYSPLIT back trajectory model is used to determine the origin of the data registered. DREAM code calculations [2] are used to forecast the air mass trajectory. The information obtained combined with a full set of corresponding meteorological parameters is transmitted via a high frequency radio telecommunication system to the Internet.

Yield of Prompt Gamma Radiation in Slow-Neutron Induced Fission of 235U as a Function of the Total Fragment Kinetic Energy

Energy Technology Data Exchange (ETDEWEB)

Albinsson, H [Chalmers Univ. of Technology, Goeteborg (SE)

1971-07-01

Fission gamma radiation yields as functions of the total fragment kinetic energy were obtained for 235U thermal-neutron induced fission. The fragments were detected with silicon surface-barrier detectors and the gamma radiation with a Nal(Tl) scintillator. In some of the measurements mass selection was used so that the gamma radiation could also be measured as a function of fragment mass. Time discrimination between the fission gammas and the prompt neutrons released in the fission process was employed to reduce the background. The gamma radiation emitted during different time intervals after the fission event was studied with the help of a collimator, the position of which was changed along the path of the fission fragments. Fission-neutron and gamma-ray data of previous experiments were used for comparisons of the yields, and estimates were made of the variation of the prompt gamma-ray energy with the total fragment kinetic energy

A Search Technique for Weak and Long-Duration Gamma-Ray Bursts from Background Model Residuals

Science.gov (United States)

Skelton, R. T.; Mahoney, W. A.

1993-01-01

We report on a planned search technique for Gamma-Ray Bursts too weak to trigger the on-board threshold. The technique is to search residuals from a physically based background model used for analysis of point sources by the Earth occultation method.

Measurement of background gamma radioactivity level in Rize and its towns

International Nuclear Information System (INIS)

Keser, R.; Dizman, S.; Goeruer, F. K.; Okumusoglu, N. T.

2006-01-01

Naturally occurring primordial radionuclides are present in various degrees in all media in the environment, including the human body itself. Only the radionuclides with half-lives comparable to the age of the earth, and their decay products and radioisotopes such as 1 37Cs, 9 0Sr from man made sources such as Chernobyl accident and nuclear tests are present in the environment. The irradiation of the human body from external sources is mainly by gamma radiation from radionuclides in the 2 38U and 2 32Th series such as 2 14 Pb, 2 28Ac and from 4 0K and 1 37Cs. The aim of this study was to measure background γ-ray activities and distributions of natural radionuclides in selected regions in Rize, such as Iyidere, Derepazari, Cayeli, Pazar, Ardesen, Findikli towns which are on the coast of Black Sea and from inland towns Ikizdere, Kalkandere, Camlihemsin and Hemsin. The geographical distribution of natural radionuclides 2 14Bi , 2 28Ac 4 0K and 1 37Cs their γ-ray activities and respective annual effective dose rates were determined using a high performance hand-held Canberra Inspector 1000 spectrometer for all of regions at various times with a week period. Surface gamma measurements (cps) and dose rate measurements show different values at different regions. The outdoor terrestrial gamma annual effective doses in air at 1 m above ground fluctuates between 0.16 to 0.55 mSv/y with an average of 0.38 mSv/y . The gamma dose rate in air due to natural radionuclides measured in Rize district in the present study have been found to be lower than the global average 0.48 mSv/y

The Imprint of the Extragalactic Background Light in the Gamma-Ray Spectra of Blazars

Science.gov (United States)

Ackermann, M.; Ajello, M.; Allafort, A.; Schady, P.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R; Blandford, R. D.;

Gamma-ray induced doppler broadening

International Nuclear Information System (INIS)

Robinson, S.J.

1992-01-01

The ultra high resolving power of the GAMS4 double-flat crystal spectrometer (M.S. Dewey et al Nucl. Instrum. Methods A 284 (1989) 151.) has been used to observe the Doppler broadening of gamma-rays emitted by nuclei recoiling at speeds as low as 10 -6 c. Such recoils may be induced by the previous emission of gamma-radiation following thermal neutron capture. If the population mechanism of an excited state is known (or can be approximated) and the slowing down mechanism can be modeled, then this technique can be used to extract the lifetime of excited nuclear states. The combination of this technique and the neutron capture reaction allows the study of states which cannot necessarily be accessed by other means. This has allowed the resolution of a number of long standing questions in low-spin nuclear structure. The basis of the technique is discussed and a number of examples given

Comparison of background gamma-ray spectra between Los Alamos, New Mexico and Austin, Texas

International Nuclear Information System (INIS)

Horne, S.; Jackman, K.R.; Landsberger, S.

2013-01-01

Background counts in gamma-ray spectrometry are caused by a variety of sources. Among these are naturally occurring radioactive materials (NORM) in the environment, interactions from cosmic radiation, and contamination within the laboratory. High-purity germanium detectors were used to acquire long background spectra in Los Alamos, NM (elevation ∼7,300 feet) and Austin, TX (elevation ∼500 feet). This difference in elevation has a sizeable effect on background spectra due to cosmic interactions, such as (n,n') and (n,γ). Los Alamos also has a fairly high NORM concentration in the soil relative to Austin, and this gives way to various spectral interferences. When analyzing nuclear forensics samples, these background sources can have non-trivial effects on detection limits of low-level fission products. By accurately determining the influence that elevation and environment have on background spectra, interferences within various laboratory environments can be more accurately characterized. (author)

Angular Distribution of Gamma Rays from the Fission of {sup 235}U Induced by 14-Mev Neutrons

Energy Technology Data Exchange (ETDEWEB)

Jeki, L.; Kluge, Gy.; Lajtai, A. [Central Research Institute for Physics, Hungarian Academy of Sciences (Hungary)

1969-12-15

Experiments are reported which were performed to study the angular distribution of the gamma radiation following fast-neutron-induced nuclear fission. The investigations were, in particular, focussed on the influence which the angular momentum imparted to the compound nucleus by the fast neutrons has on the angular distribution of the {gamma}-rays. The fission of {sup 235}U is induced by 14-MeV-energy neutrons from the T(d, n) {alpha} reaction. The fission fragments are detected by a gas-scintillation counter filled with a mixture of Ar and Ni gases, the {gamma}-rays by 5 cm x 5 cm Nal(Tl) crystal with an energy threshold of 120 keV. The intensity of the {gamma}-rays is measured at 90 Degree-Sign and 174 Degree-Sign to the direction of fragment motion. The flight times of fission neutrons and {gamma}-rays are measured with a 20-ns overlap-type time-to-pulse height converter while the background was covered simultaneously with another converter delayed with respect to the former. The signals from both converters are analysed by a multichannel analyser with divisible memory. The flight path, which is chosen to be about 70 cm, makes it possible to separate the neutron from the gamma counts. The geometry is designed to keep the direction of the outflying fission fragments nearly the same as that of the incident fast neutrons. In this way the angular momenta of the fast neutrons are normal to the flight path of the fragments. The measured gamma intensities are extrapolated to 180 Degree-Sign on a computer using Strutinski's formula n( Greek-Theta-Symbol ) {approx}1 + B sin Greek-Theta-Symbol . On transformation of the measured data from the laboratory system to the system of fragments the anisotropy is found to be A = 1(180 Degree-Sign )/l (90 Degree-Sign ) = 1.33 {+-} 0.05. The main angular momentum of fission fragments is calculated from the anisotropy as 15 h units. As compared with the thermal-neutron-induced fission the present results indicate an additional

Application of the image calorimeter in the high energy gamma astronomy

Energy Technology Data Exchange (ETDEWEB)

Casolino, M.; Sparvoli, R.; Morselli, A.; Picozza, P. [Rome Univ. `Tor Vergata` (Italy). Dip. di Fisica]|[INFN, Sezione Univ. `Tor Vergata`, Rome (Italy); Carlson, P. [Royal Institute of Technology, Stockholm (Sweden); Fuglesang, C. [ESA-EAC, Cologne (Germany); Ozerov, Yu.V.; Zemskov, V.M.; Zverev, V.G.; Galper, A.M. [Moscow Engineering Physics Institute, Moscow (Russian Federation)

1995-09-01

The capability of registration of the primary high energy cosmic ray gamma emission by a gamma-telescope made of an image calorimeter is shown in this paper. The problem of triggering and off-line identification of primary particles by the analysis of the electromagnetic showers induced in the calorimeter is under consideration. The estimations of the background flux of delayed secondaries induced by nuclear interactions are presented too.

Positron Annihilation Induced Auger and Gamma Spectroscopy of Catalytically Important Surfaces

Science.gov (United States)

Weiss, A. H.; Nadesalingam, M. P.; Sundaramoorthy, R.; Mukherjee, S.; Fazleev, N. G.

2006-10-01

The annihilation of positrons with core electrons results in unique signatures in the spectra of Auger-electron and annihilation-gamma rays that can be used to make clear chemical identification of atoms at the surface. Because positrons implanted at low energies are trapped with high efficiency in the image-correlation well where they are localized just outside the surface it is possible to use annihilation induced Auger and Gamma signals to probe the surfaces of solids with single atomic layer depth resolution. In this talk we will report recent applications of Positron Annihilation Induced Auger Electron Spectroscopy (PAES) and Auger-Gamma Coincidence Spectroscopy (AGCS) to the study of surface structure and surface chemistry. Our research has demonstrated that PAES spectra can provide new information regarding the composition of the top-most atomic layer. Applications of PAES to the study of catalytically important surfaces of oxides and wide band-gap semiconductors including TiO2, SiO2,Cu2O, and SiC will be presented. We conclude with a discussion of the use of Auger-Gamma and Gamma-Gamma coincidence spectroscopy for the study of surfaces at pressures closer to those found in practical chemical reactors. Research supported by the Welch Foundation Grant Number Y-1100.

Preliminary study about frequencies of unstable chromosome alterations induced by gamma beam and neutron-gamma mixed field

International Nuclear Information System (INIS)

Mendes, Mariana E.; Souza, Priscilla L.G.; Brandao, Jose Odinilson de C.; Santos, Joelan A.L.; Vilela, Eudice C.; Lima, Fabiana F.; Calixto, Merilane S.; Santos, Neide

2011-01-01

The estimate on approximate dose in exposed individual can be made through conventional cytogenetic analysis of dicentric, this technique has been used to support physical dosimetry. It is important to estimate the absorbed dose in case of accidents with the aim of developing an appropriate treatment and biological dosimetry can be very useful in case where the dosimetry is unavailable. Exposure to gamma and neutron radiation leads to the same biological effects such as chromosomal alterations and cancer. However, neutrons cause more genetic damage, such as mutation or more structural damage, such as chromosome alterations. The aim of research is to compare frequencies of unstable chromosome alterations induced by a gamma beam with those from neutron-gamma mixed field. Two blood samples were obtained from one healthy donor and irradiated at different sources. The first sample was exposed to mixed field neutron-gamma sources 241 AmBe at the Neutron Calibration Laboratory (NCL - CRCN/NE - PE - Brazil) and the second one was exposed to 137 Cs gamma rays at 137 Cs Laboratory (CRCN/NE - PE - Brazil), both exposures resulting in an absorbed dose of 0.66Gy. Mitotic metaphase cells were obtained by lymphocyte culture for chromosomal analysis and slides were stained with Giemsa 5%. These preliminary results showed a similarity in associated dicentrics frequency per cell (0.041 and 0.048) after 137 Cs and 241 AmBe sources irradiations, respectively. However, it was not observed centric rings frequency per cell (0.0 and 0.027). This study will be continue to verify the frequencies of unstable chromosome alterations induced by only gamma beam and neutron-gamma mixed field. (author)

Preliminary study about frequencies of unstable chromosome alterations induced by gamma beam and neutron-gamma mixed field

Energy Technology Data Exchange (ETDEWEB)

Mendes, Mariana E.; Souza, Priscilla L.G.; Brandao, Jose Odinilson de C.; Santos, Joelan A.L.; Vilela, Eudice C.; Lima, Fabiana F. [Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Calixto, Merilane S.; Santos, Neide [Universidade Federal de Pernanmbuco (CCB/UFPE), Recife, PE (Brazil). Centro de Ciencias Biologicas. Dept. de Genetica

2011-07-01

The estimate on approximate dose in exposed individual can be made through conventional cytogenetic analysis of dicentric, this technique has been used to support physical dosimetry. It is important to estimate the absorbed dose in case of accidents with the aim of developing an appropriate treatment and biological dosimetry can be very useful in case where the dosimetry is unavailable. Exposure to gamma and neutron radiation leads to the same biological effects such as chromosomal alterations and cancer. However, neutrons cause more genetic damage, such as mutation or more structural damage, such as chromosome alterations. The aim of research is to compare frequencies of unstable chromosome alterations induced by a gamma beam with those from neutron-gamma mixed field. Two blood samples were obtained from one healthy donor and irradiated at different sources. The first sample was exposed to mixed field neutron-gamma sources {sup 241}AmBe at the Neutron Calibration Laboratory (NCL - CRCN/NE - PE - Brazil) and the second one was exposed to {sup 137}Cs gamma rays at {sup 137}Cs Laboratory (CRCN/NE - PE - Brazil), both exposures resulting in an absorbed dose of 0.66Gy. Mitotic metaphase cells were obtained by lymphocyte culture for chromosomal analysis and slides were stained with Giemsa 5%. These preliminary results showed a similarity in associated dicentrics frequency per cell (0.041 and 0.048) after {sup 137}Cs and {sup 241}AmBe sources irradiations, respectively. However, it was not observed centric rings frequency per cell (0.0 and 0.027). This study will be continue to verify the frequencies of unstable chromosome alterations induced by only gamma beam and neutron-gamma mixed field. (author)

Assessment of background gamma radiation levels around Tummalapalle uranium mining and processing facility, Andhra Pradesh

International Nuclear Information System (INIS)

Rana, B.K.; Dhumale, M.R.; Molla, Samim; Rao, K.B.; Jha, S.K.; Tripathi, R.M.; Sahu, S.K.

2018-01-01

Natural environmental radioactivity and the associated external exposure due to gamma radiation depend primarily on the geological and geographical conditions, and appear at different levels in the soil of each region in the world. The dose received by the population in a region comprises of (i) external gamma radiation dose due to cosmic rays and primordial radionuclides; (ii) inhalation dose due to radon, thoron and their progeny, and (iii) ingestion dose due to the intake of radionuclides through the consumption of food, milk, water, etc. In this study, background gamma radiation level around Tummalapalle uranium mining and processing site was estimated by using radiation survey meter and deploying environmental TLDs. The generated data can be served as baseline for this area for future comparison for prolonged operation of the plant, for the upcoming adjacent projects and during decommissioning phase of the mine, mill and tailings pond

Protective effects of vitamin C against gamma-ray induced wholly damage and genetic damage

International Nuclear Information System (INIS)

Fu Chunling; Jiang Weiwei; Zhang Ping; Chen Xiang; Zhu Shengtao

2000-01-01

Objective: Protective effects of supplemental vitamin C against 60 Co-gamma-ray induced wholly damage and genetic damage was investigated in mice. Method: Mice were divided into normal control group, irradiation control group and vitamin C experimental group 1,2,3 (which were orally given vitamin C 15, 30, 45 mg/kg.bw for 10 successive days respectively prior to gamma-ray irradiation). Micronuclei in the bone marrow polychromatophilic erythrocytes in each group of mice were examined and the 30 day survival rate of mice following whole-body 5.0 Gy γ irradiation were also determined. Results: Supplemental vitamin C prior to gamma-rays irradiation can significantly decrease bone marrow PECMN rate of mice and increase 30 day survival rate and prolong average survival time. The protection factor is 2.09. Conclusion: Vitamin C has potent protective effects against gamma irradiation induced damage in mice. In certain dose range, vitamin C can absolutely suppress the gamma-rays induced genetic damage in vivo

Comparison of gamma radiation - induced effects in two human prostate cancer cells

International Nuclear Information System (INIS)

Vucic, V.; Adzic, M.; Ruzdijic, S.; Radojcic, M.B. . E-mail address of corresponding author: vesnav@vin.bg.ac.yu; Vucic, V.)

2005-01-01

In this study, the effects of gamma radiation on two hormone refractory human prostate cancer cell lines, DU 145 and PC-3, were followed. It was shown that gamma radiation induced significant inhibition of cell proliferation and viability in dose dependent manner. Antiproliferative effects of radiation were similar in both cell lines, and more pronounced than cytotoxic effects. In addition to that, PC-3 cell line was more resistant to radiation -induced cytotoxicity. (author)

Modification of silica surface by gamma ray induced Ad micellar Polymerization

International Nuclear Information System (INIS)

Buathong, Salukjit; Pongprayoon, Thirawudh; Suwanmala, Phiriyatorn

2005-10-01

Precipitated silica is often added to natural rubber compounds in order to improve performance in commercial application. A problem with using silica as filler is the poor compatibility between silica and natural rubber. In this research, polyisoprene was coated on silica surface by gamma ray induced ad micellar polymerization in order to achieve the better compatibility between silica and natural rubber. The modified silica was characterized by FT-IR, and SEM. The results show that polyisoprene was successfully coated on silica surface via gamma ray induced ad micellar polymerization

Background suppression in TeO2 bolometers with Neganov-Luke amplified cryogenic light detectors

International Nuclear Information System (INIS)

Willers, Michael

2015-01-01

Cryogenic detectors based on non-scintillating TeO 2 crystals are used in the search for the neutrinoless double beta decay, presently one of the most important fields of research in neutrino and astroparticle physics. Within this work, the application of Neganov-Luke amplified cryogenic light detectors for the background suppression in TeO 2 crystals is investigated. Alpha-induced background events can be discriminated from signal-like electron/gamma events via the detection of Cherenkov radiation produced by highly energetic electrons within the TeO 2 crystal. Using Neganov-Luke light detectors, it could be shown for the first time that a highly efficient event-by-event discrimination between alpha and electron/gamma-induced events can be achieved.

Angular distribution of gamma rays from the fission of {sup 235}U induced by 14-MeV neutrons

Energy Technology Data Exchange (ETDEWEB)

Jeki, L; Kluge, G; Lajtai, A [Central Research Institute for Physics, Hungarian Academy of Sciences (Hungary)

1969-12-15

Experiments are reported which were performed to study the angular distribution of the gamma radiation following fast-neutron-induced nuclear fission. The investigations were, in particular, focussed on the influence which the angular momentum imparted to the compound nucleus by the fast neutrons has on the angular distribution of the {gamma}-rays. The fission of {sup 235}U is induced by 14-MeV-energy neutrons from the T(d, n) {alpha} reaction. The fission fragments are detected by a gas-scintillation counter filled with a mixture of Ar and Ni gases, the {gamma}-rays by 5 cm x 5 cm Nal(Tl) crystal with an energy threshold of 120 keV. The intensity of the {gamma}-rays is measured at 90 deg. and 174 deg. to the direction of fragment motion. The flight times of fission neutrons and {gamma}-rays are measured with a 20-ns overlap-type time-to-pulse height converter while the background was covered simultaneously with another converter delayed with respect to the former. The signals from both converters are analysed by a multichannel analyser with divisible memory. The flight path, which is chosen to be about 70 cm, makes it possible to separate the neutron from the gamma counts. The geometry is designed to keep the direction of the outflying fission fragments nearly the same as that of the incident fast neutrons. In this way the angular momenta of the fast neutrons are normal to the flight path of the fragments. The measured gamma intensities are extrapolated to 180 deg on a computer using Strutinski's formula n({theta}) {approx} 1 + B sin {theta}. On transformation of the measured data from the laboratory system to the system of fragments the anisotropy is found to be A = I(180 deg.)/I (90 deg.) = 1.33 {+-} 0.05. The main angular momentum of fission fragments is calculated from the anisotropy as 15 (h/2{pi}) units. As compared with the thermal-neutron-induced fission the present results indicate an additional contribution from the angular momentum of the compound

Neutron- and muon-induced background in underground physics experiments

International Nuclear Information System (INIS)

Kudryavtsev, V.A.; Tomasello, V.; Pandola, L.

2008-01-01

Background induced by neutrons in deep underground laboratories is a critical issue for all experiments looking for rare events, such as dark matter interactions or neutrinoless ββ decay. Neutrons can be produced either by natural radioactivity, via spontaneous fission or (α, n) reactions, or by interactions initiated by high-energy cosmic rays. In all underground experiments, Monte Carlo simulations of neutron background play a crucial role for the evaluation of the total background rate and for the optimization of rejection strategies. The Monte Carlo methods that are commonly employed to evaluate neutron-induced background and to optimize the experimental setup, are reviewed and discussed. Focus is given to the issue of reliability of Monte Carlo background estimates. (orig.)

Neutron- and muon-induced background in underground physics experiments

Energy Technology Data Exchange (ETDEWEB)

Kudryavtsev, V.A.; Tomasello, V. [University of Sheffield, Department of Physics and Astronomy, Sheffield (United Kingdom); Pandola, L. [Laboratori Nazionali del Gran Sasso, INFN, Assergi (Italy)

2008-05-15

Background induced by neutrons in deep underground laboratories is a critical issue for all experiments looking for rare events, such as dark matter interactions or neutrinoless {beta}{beta} decay. Neutrons can be produced either by natural radioactivity, via spontaneous fission or ({alpha}, n) reactions, or by interactions initiated by high-energy cosmic rays. In all underground experiments, Monte Carlo simulations of neutron background play a crucial role for the evaluation of the total background rate and for the optimization of rejection strategies. The Monte Carlo methods that are commonly employed to evaluate neutron-induced background and to optimize the experimental setup, are reviewed and discussed. Focus is given to the issue of reliability of Monte Carlo background estimates. (orig.)

Background {sup 99m}Tc-methoxyisobutylisonitrile uptake of breast-specific gamma imaging in relation to background parenchymal enhancement in magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Yoon, Hai-Jeon; Kim, Bom Sahn [Ewha Womans University, Department of Nuclear Medicine, Yangchun-Ku, Seoul (Korea, Republic of); Kim, Yemi [Ewha Womans University, Clinical Research Institute and Department of Conservative Dentistry, Seoul (Korea, Republic of); Lee, Jee Eun [Ewha Womans University, Department of Radiology, Seoul (Korea, Republic of)

2015-01-15

This study investigated factors that could affect background uptake of {sup 99m}Tc- methoxyisobutylisonitrile (MIBI) on normal breast by breast-specific gamma imaging (BSGI). In addition, the impact of background {sup 99m}Tc-MIBI uptake on the diagnostic performance of BSGI was further investigated. One hundred forty-five women with unilateral breast cancer who underwent BSGI, MRI, and mammography were retrospectively enrolled. Background uptake on BSGI was evaluated qualitatively and quantitatively. Patients were classified into non-dense and dense breast groups according to mammographic breast density. Background parenchymal enhancement (BPE) was rated according to BI-RADS classification. The relationship of age, menopausal status, mammographic breast density, and BPE with background {sup 99m}Tc-MIBI uptake was analyzed. Heterogeneous texture and high background uptake ratio on BSGI were significantly correlated with younger age (p < 0.001, respectively), premenopausal status (p < 0.001 and p = 0.003), dense breast (p < 0.001, respectively), and marked BPE (p < 0.001, respectively). On multivariate analysis, only BPE remained a significant factor for background MIBI uptake (p < 0.001).There was a significant reduction in positive predictive value (p = 0.024 and p = 0.002) as background MIBI uptake and BPE grade increased. BPE on MRI was the most important factor for background MIBI uptake on BSGI. High background MIBI uptake or marked BPE can diminish the diagnostic performance of BSGI. (orig.)

Hypoxia upregulates Bcl-2 expression and suppresses interferon-gamma induced antiangiogenic activity in human tumor derived endothelial cells.

LENUS (Irish Health Repository)

Wang, Jiang Huai

2012-02-03

BACKGROUND: Hypoxia in solid tumors potentially stimulates angiogenesis by promoting vascular endothelial growth factor (VEGF) production and upregulating VEGF receptor expression. However, it is unknown whether hypoxia can modulate the effect of anti-angiogenic treatment on tumor-derived endothelium. METHODS: Human tumor-derived endothelial cells (HTDEC) were freshly isolated from surgically removed human colorectal tumors by collagenase\\/DNase digestion and Percol gradient sedimentation. Cell proliferation was assessed by measuring BrdU incorporation, and capillary tube formation was measured using Matrigel. Cell apoptosis was assessed by flow cytometry and ELISA, and Bcl-2 expression was detected by Western blot analysis. RESULTS: Under aerobic culture conditions (5% CO2 plus 21% O2) HTDEC expressed less Bcl-2 and were more susceptible to IFN-gamma-induced apoptosis with significant reductions in both cell proliferation and capillary tube formation, when compared with normal human macrovascular and microvascular EC. Following exposure of HTDEC to hypoxia (5% CO2 plus 2% O2), IFN-gamma-induced cell apoptosis, and antiangiogenic activity (i.e. an inhibition in cell proliferation and capillary tube formation) in HTDEC were markedly attenuated. This finding correlated with hypoxia-induced upregulation of Bcl-2 expression in HTDEC. CONCLUSIONS: These results indicate that hypoxia can protect HTDEC against IFN-gamma-mediated cell death and antiangiogenic activity, and suggest that improvement of tumor oxygenation may potentiate the efficacy of anti-cancer therapies specifically targeting the inhibition of tumor angiogenesis.

Gamma ray induced fruit quality variations in banana variety Nendran (Musa Paradasiaca L.)

International Nuclear Information System (INIS)

Radha Devi, D.S.; Nayer, N.K.

1992-01-01

Gamma ray induced fruit quality variation was envisaged to analyse the direct effect of Co 60 gamma rays in banana variety Nendran. Fruit quality analysis showed that the total soluble solids and acidity decreased and total sugar and sugar acid ratio increased with increase in dose of gamma ray exposures. (author). 5 refs., 1 tab

Ageing effects in As10Se90 chalcogenide glasses induced by gamma-irradiation

International Nuclear Information System (INIS)

Golovchak, R.; Shpotyuk, O.; Shpotyuk, M.; Gorecki, Cz.; Kozdras, A.

2005-01-01

The peculiarities of gamma-induced (Co 60 source, 1.85 MGy absorbed dose) ageing phenomena in As 10 Se 90 chalcogenide glasses are investigated for the first time. The analogy between the observed radiation-induced ageing and the thermally induced one in vitreous selenium is emphasized. Like to thermal treatment, gamma-irradiation leads to an increase in the glass transition temperature and the relaxation rate towards a thermodynamic equilibrium of supercooled liquid, the value of this increase being greater in the case of radiation influence

In vitro activated CD4+ T cells from interferon-gamma (IFN-gamma)-deficient mice induce intestinal inflammation in immunodeficient hosts

DEFF Research Database (Denmark)

Bregenholt, S; Brimnes, J; Nissen, Mogens Holst

1999-01-01

To investigate the role of IFN-gamma in the immunopathogenesis of inflammatory bowel disease (IBD), severe combined immunodeficient (SCID) mice were transplanted with in vitro activated CD4+ T cells from either wild-type (WT) or IFN-gamma-deficient (IFN-gammaKO) BALB/c mice. In vitro, the two types...... of T cells displayed comparable proliferation rates and production of tumour necrosis factor-alpha (TNF-alpha), IL-2, IL-4 and IL-10 after concanavalin A (Con A) stimulation. When transplanted into SCID mice, WT CD4+ blasts induced a lethal IBD, whereas IFN-gammaKO blasts induced a less severe...... intestinal inflammation with moderate weight loss. Intracellular cytokine staining of lamina propria lymphocytes (LPL) revealed comparable fractions of CD4+ T cells positive for TNF-alpha, IL-2 and IL-10 in the two groups of transplanted SCID mice, whereas a two-to-three-fold increase in the fraction of IL-4...

Gamma Irradiation Induced Degradation of Orange Peels

Directory of Open Access Journals (Sweden)

Jaime Saucedo Luna

2012-08-01

Full Text Available In this study, gamma irradiation induced degradation of orange peels (OP was investigated. The lignocellulosic biomass degradation was carried out at doses of 0 (control, 600, 1800 and 3500 kGy using a Co-60 gamma radiation source. The samples were tested for total and reducing sugars. The concentrations of total sugars ranged from 0.530 g∙g⁻¹ in control sample to 0.382 g∙g⁻¹ of dry weight in the sample which received the highest radiation dose. The reducing sugars content varying from 0.018 to 0.184 g∙g⁻¹ of dry weight with the largest rise occurring in the sample irradiated at 3500 kGy. The concentrations of sucrose, glucose and fructose were determined. The changes generated in physico-chemical properties were determined by Fourier Transform Infrared Spectroscopy (FTIR and termogravimetric analysis (TG-DTG. The results show that OP was affected, but not significantly, which suggests that lignocellulose and sugars profiles were partially degraded after gamma irradiation.

Geographically determined dependencies in the value of the constant natural radiation gamma-background

International Nuclear Information System (INIS)

Miloslavov, V.

2001-01-01

The problem of the assessment of the influence of natural gamma background changes on the population is discussed. It is considered that the populations in different geographic regions have adapted by evolution mechanisms to the respective unchanged (without human activities) radiation background. The background limits for each area form the 'radiation comfortable zone' which varies very much for the different geographic areas. Leaving the 'comfortable zone' leads to a triggering of adaptive mechanisms in the population including the natural selection in order to reach an equilibrium. Thus, the radiation impact exceeding the 'comfortable zone' is expected to cause harm for a part of the population which is preliminarily burden or uncapable to adapt. From this point of view the increased morbidity due to radiation factor in those cases remains hidden. As a conclusion it is pointed out that the proposed increase of the annual dose for the population might result with harmful consequences for the whole human population

Interpretation of the radioactive background observed in the OSO-7 gamma ray monitor

International Nuclear Information System (INIS)

Dyer, C.S.

1975-01-01

Application of a spallation activation calculation to the OSO-7 gamma-ray monitor background shows that major line features and about 30% of the continuum can be understood as activation of the central detector crystal by trapped protons. Weaker line features arise from activation of materials unshielded by the anticoincidence cup, while the remaining continuum and annihilation line would seem to come largely continuum and annihilation line would seem to come largely from electron-photon cascades originating in the spacecraft. (orig.) [de

Verification of Gamma-ray Sensitivity for BF3 Neutron Detection System

International Nuclear Information System (INIS)

Choi, Yu Sun; Cho, Jin Bok; Lyou, Seok Jean

2016-01-01

The BF3(Boron Tri-Fluorides) gas filled neutron detector(hereafter BF3 Detector) is commonly used for nuclear reactor’s startup channel due to its relatively high neutron efficiency and good discrimination against gamma-ray backgrounds. In order to measure how much this gamma-ray will affect on BF3 neutron detector performance in view of gamma noise discrimination, Multi-Channel Analyzer(MCA) is utilized for spectrum based signal analysis. The pre-test of BF3 Detector should be performed in an area where the ionization does not exceed 2.5 micro Gy/Hr(Ref.1). In this paper, the discrimination level (Voltage Unit) is verified by experimentally measurement if that discrimination level is acceptable within the criteria or not before installation. The maximum discrimination level, so called LLD, is determined by experimentally measurement. This BF3 Detector (LND20372) is insensitive under 540 micro Gy/Hr of gamma ray and 0.3V of LLD could cut off a background and gamma induced signal in a laboratory. MCA could be a convenient tool for spectrum analysis of signals that induced from gamma ray and a time saving tool rather than oscilloscope investigation due to its function to integrate all input signals at a sudden duration

Sample analysis using gamma ray induced fluorescent X-ray emission

Energy Technology Data Exchange (ETDEWEB)

Sood, B S; Allawadhi, K L; Gandhi, R; Batra, O P; Singh, N [Punjabi Univ., Patiala (India). Nuclear Science Labs.

1983-01-01

A non-destructive method for the analysis of materials using gamma ray-induced fluorescent x-ray emission has been developed. In this method, special preparation of very thin samples in which the absorption of the incident gamma rays and the emitted fluorescent x-rays is negligible, is not needed, and the absorption correction is determined experimentally. A suitable choice of the incident gamma ray energies is made to minimise enhancement effects through selective photoionization of the elements in the sample. The method is applied to the analysis of a typical sample of the soldering material using 279 keV and 59.5 keV gamma rays from /sup 203/Hg and /sup 241/Am radioactive sources respectively. The results of the analysis are found to agree well with those obtained from the chemical analysis.

Anisotropy of the cosmic gamma-ray background from dark matter annihilation

International Nuclear Information System (INIS)

Ando, Shin'ichiro; Komatsu, Eiichiro

2006-01-01

High-energy photons from pair annihilation of dark matter particles contribute to the cosmic gamma-ray background (CGB) observed in a wide energy range. Since dark matter particles are weakly interacting, annihilation can happen only in high density regions such as dark matter halos. The precise shape of the energy spectrum of CGB depends on the nature of dark matter particles--their mass and annihilation cross section, as well as the cosmological evolution of dark matter halos. In order to discriminate between the signals from dark matter annihilation and other astrophysical sources, however, the information from the energy spectrum of CGB may not be sufficient. We show that dark matter annihilation not only contributes to the mean CGB intensity, but also produces a characteristic anisotropy, which provides a powerful tool for testing the origins of the observed CGB. We develop the formalism based on a halo model approach to analytically calculate the three-dimensional power spectrum of dark matter clumping, which determines the power spectrum of annihilation signals. We show that the expected sensitivity of future gamma-ray detectors such as the Gamma Ray Large Area Space Telescope (GLAST) should allow us to measure the angular power spectrum of CGB anisotropy, if dark matter particles are supersymmetric neutralinos and they account for most of the observed mean intensity of CGB in GeV region. On the other hand, if dark matter has a relatively small mass, on the order of 20 MeV, and accounts for most of the CGB in MeV region, then the future Advanced Compton Telescope (ACT) should be able to measure the angular power spectrum in MeV region. As the intensity of photons from annihilation is proportional to the density squared, we show that the predicted shape of the angular power spectrum of gamma rays from dark matter annihilation is different from that due to other astrophysical sources such as blazars and supernovae, whose intensity is linearly proportional to

Laser-induced nuclear orientation and gamma anisotropy in sodium

International Nuclear Information System (INIS)

Pappas, P.G.

1980-12-01

The use of laser optical pumping to induce nuclear orientation in several isotopes and one isomer of atomic sodium vapor is described. Essentially complete nuclear polarization, P > 90%, has been achieved in stable 23 Na when pumping with modest laser intensities (I approx. = 10 mW/cm 2 ). The volume of the sample cell was approximately 10 cc, and was filled with a sodium density of about 10'' atoms/cc. Complete coverage of the Doppler distribution was accomplished with the use of trace amounts (less than or equal to 1 torr) of argon buffer gas to induce velocity changing collisions. A theoretical model which accurately predicts the amount of polarization is developed. The orientation of nuclei which are unstable to gamma decay can manifest itself in anisotropic gamma ray emission. This anisotropy can be used to measure isotope and isomer shifts, from which nuclear properties can be derived. Gamma anisotropy was observed in two systems, 22 Na and /sup 24m/Na. From the observed anisotropy in /sup 24m/Na, a negative sign for the g factor is determined. Values are derived for the magnetic moment, μ = 2.56 +- 0.64 nm, and the isomer shift, deltaν/sub 24m/ = 288 +- 191 MHz (D1 line). A model is described which relates various laser and fubber gas parameters to the observed gamma anisotropy lineshape. This model facilitates the extraction of physical parameters from knowledge of the laser frequency at which the anisotropy is a maximum

Calculation of the correlation coefficients between the numbers of counts (peak areas and backgrounds) obtained from gamma-ray spectra

International Nuclear Information System (INIS)

Korun, M.; Vodenik, B.; Zorko, B.

2016-01-01

Two simple methods for calculating the correlations between peaks appearing in gamma-ray spectra are described. We show how the areas are correlated when the peaks do not overlap, but the spectral regions used for the calculation of the background below the peaks do. When the peaks overlap, the correlation can be stronger than in the case of the non-overlapping peaks. The methods presented are simplified to the extent of allowing their implementation with manual calculations. They are intended for practitioners as additional tools to be used when the correlations between the areas of the peaks in the gamma-ray spectra are to be calculated. Also, the correlation coefficient between the number of counts in the peak and the number of counts in the continuous background below the peak is derived. - Highlights: • The correlation coefficients between areas of closely spaced peaks are assessed. • For isolated peaks the correlation arises from the common continuous background. • If peaks overlap the correlation coefficient depends on how much they overlap. • If peaks overlap also the background height affects the correlation coefficient. • The correlation coefficient between the peak area and its background is −1.

Use of a low-background and anti-Compton HpGe gamma-spectrometer in analyses of environmental samples

Energy Technology Data Exchange (ETDEWEB)

Qiong, Su; Yamin, Gao [Ministry of Public Health, Beijing, BJ (China). Lab. of Industrial Hygiene

1989-12-01

The results of application of a HpGe gamma-spectrometer in the analyses of enviromental samples are reported. The spectrometer has very low background and good property of Compton suppression. By comparison between the gamma-spectra with and without anti-coincidence shield for the same samples, the advantage in analysing environmental samples became apparent. In the analyses of carp samples, the ratio of specific activities of {sup 226}Ra in the flesh and bone of the carp was 1 to 35, which is basically in agreement with the ratio of the accumulation factors 1:37, as reported in the literature. Thus the spectrometer would play an important role in the research of the transfer of radionuclides of low activity in the environment. The method of gamma-ray data processing is also described.

Use of a low-background and anti-Compton HpGe gamma-spectrometer in analyses of environmental samples

International Nuclear Information System (INIS)

Su Qiong; Gao Yamin

1989-01-01

The results of application of a HpGe gamma-spectrometer in the analyses of enviromental samples are reported. The spectrometer has very low background and good property of Compton suppression. By comparison between the gamma-spectra with and without anti-coincidence shield for the same samples, the advantage in analysing environmental samples became apparent. In the analyses of carp samples, the ratio of specific activities of 226 Ra in the flesh and bone of the carp was 1 to 35, which is basically in agreement with the ratio of the accumulation factors 1:37, as reported in the literature. Thus the spectrometer would play an important role in the research of the transfer of radionuclides of low activity in the environment. The method of gamma-ray data processing is also described

Cell death induced by gamma irradiation of developing skeletal muscle

International Nuclear Information System (INIS)

Olive, M.; Blanco, R.; Rivera, R.; Cinos, C.; Ferrer, I.

1995-01-01

Newborn Sprague-Dawley rats were exposed to a single dose of 2 Gy gamma rays and killed from 6 h to 5 d later. Increased numbers of dying cells, characterised by their extreme chromatin condensation and often nuclear fragmentation were seen in skeletal muscle 6 h after irradiation. Dying cells decreased to nearly normal values 48 h later. In situ labelling of nuclear DNA fragmentation identified individual cells bearing fragmented DNA. The effects of gamma rays were suppressed following cycloheximide i.p. at a dose of 1 μg/g body weight given at the time of irradiation. Taken together, the present morphological and pharmacological results suggest that gamma ray induced cell death in skeletal muscle is apoptotic, and that the process is associated with protein synthesis. Finally, proliferating cell nuclear antigen-immunoreactive cells, which were abundant in control rats, decreased in number 48 h after irradiation. However, a marked increase significantly above normal age values was observed at the 5th day, thus suggesting that regeneration occurs following irradiation-induced cell death in developing muscle. (author)

Evaluation of Chemical Changes in Some Soybean Mutants Induced by Gamma Irradiation

International Nuclear Information System (INIS)

Abd-Elkalik, K.; Mekkawy, S.H.; El-Demerdash, H.M.

2010-01-01

The Egyptian soybean cultivar Giza-22 was used to induce genetic variability by using gamma rays at dose levels of 100, 150 and 200 Gy. Sixteen mutants (including parental cultivar) were evaluated in M3 generation for their agronomic traits and chemical analysis was done in seeds of M3 generation. Four mutants A21 (150 Gy), A22, A23 and A24 (200 Gy) showed superiority in their agronomic traits compared with parental cultivar. The results of chemical analysis of seeds of M3 generation showed that, oil and energy contents were unaffected by irradiation treatments while protein contents were significantly increased at doses 150 and 200 Gy. Phenolic and tannin contents in seeds of M3 generation showed no significant changes in their percentages due to irradiation treatments. Gamma irradiation significantly increased in linoleic acid content in most of the mutants compared with the control (Giza-22), whereas, there were decreases in linolenic acid content. Investigation of amino acid composition of mutants of M3 generation revealed significant increases in the essential amino acids in most mutants induced by gamma irradiation at 150 and 200 Gy. It could be suggested that the use of gamma irradiation can induce an improvement of the oil and protein composition in soybean

Muon-induced backgrounds in the CUORICINO experiment

Energy Technology Data Exchange (ETDEWEB)

Andreotti, E; Arnaboldi, C; Avignone, F T; Balata, M; Bandac, I; Barucci, M; Beeman, J W; Bellini, F; Bloxham, T; Brofferio, C; Bryant, A; Bucci, C; Canonica, L; Capelli, S; Carbone, L; Carrettoni, M; Clemenza, M; Cremonesi, O; Creswick, R J; Domizio, S D; Dolinski, M J; Ejzak, L; Faccini, R; Farach, H A; Ferri, E; Ferroni, F; Firoini, E; Foggetta, L; Giachero, A; Gironi, L; Giuliani, A; Gorla, P; Guardincerri, E; Gutierrez, T D; Haller, E E; Kadel, R; Kazkaz, K; Kraft, S; Kogler, L; Kolomensky, Y G; Maiano, C; Maruyama, R H; Martinez, C; Martinez, M; Mizouni, L; Morganti, S; Nisi, S; Nones, C; Norman, E B; Nucciotti, A; Orio, F; Pallavicini, M; Palmieri, V; Pattavina, L; Pavan, M; Pedretti, M; Pessina, G; Pirro, S; Previtali, E; Risegari, L; Rosenfeld, C; Rusconi, C; Salvioni, C; Sangiorgio, S; Schaeffer, D; Scielzo, N D; Sisti, M; Smith, A R; Tomei, C; Ventura, G; Vignati, M

2009-11-16

To better understand the contribution of cosmic ray muons to the CUORICINO background, ten plastic scintillator detectors were installed at the CUORICINO site and operated during 3 months of the CUORICINO experiment. From these measurements, an upper limit of 0.0021 counts/keV {center_dot} kg {center_dot} yr (95% C.L.) was obtained on the cosmic ray induced background in the neutrinoless double beta decay region of interest. The measurements were compared to Geant4 simulations, which are similar to those that will be used to estimate the backgrounds in CUORE.

GEM gas detectors for soft X-ray imaging in fusion devices with neutron–gamma background

Energy Technology Data Exchange (ETDEWEB)

Pacella, Danilo, E-mail: danilo.pacella@enea.it [Associazione EURATOM-ENEA, C.R. Frascati, Via E. Fermi 45, 00044 Frascati, Roma (Italy); Romano, Afra; Gabellieri, Lori [Associazione EURATOM-ENEA, C.R. Frascati, Via E. Fermi 45, 00044 Frascati, Roma (Italy); Murtas, Fabrizio [Istituto Nazionale di Fisica Nucleare, Via E. Fermi 45, 00044 Frascati, Roma (Italy); Mazon, Didier [Association EURATOM-CEA, CEA Cadarache, DSM/IRFM, 13108 St. Paul Lez Durance Cedex (France)

2013-08-21

A triple gas electron multiplier (GEM) detector has been built and characterized in a collaboration between ENEA, INFN and CEA to develop a soft X-ray imaging diagnostic for magnetic fusion plasmas. It has an active area of 5×5 cm{sup 2}, 128 pixels and electronics in counting mode. Since burning plasma experiments will have a very large background of radiation, this prototype has been tested with contemporary X-ray, neutron and gamma irradiation, to study the detection efficiencies, and the discrimination capabilities. The detector has been preliminarily characterized under DD neutron irradiation (2.45 MeV) up to 2.2×10{sup 6} n/s on the detector active area, showing a detection efficiency of about 10{sup −4}, while the detection efficiency of X-rays is more than three orders of magnitude higher. The detector has been also tested under DT neutron flux (14 MeV) up to 2.8×10{sup 8} n/s on the whole detector, with a detection efficiency of about 10{sup −5}. The calibration of the γ-rays detection has been done by means of a source of {sup 60}Co (gamma rays of energy 1.17 MeV and 1.33 MeV) and the detection efficiency was found of the order of 10{sup −4}. Thanks to the adjustable gain of the detector and the discrimination threshold of the electronics, it is possible to minimize the sensitivity to neutrons and gamma, and discriminate the X-ray signals even with very high radiative background.

External gamma irradiation-induced effects in early-life stages of zebrafish, Danio rerio

International Nuclear Information System (INIS)

Gagnaire, B.; Cavalié, I.; Pereira, S.; Floriani, M.; Dubourg, N.; Camilleri, V.; Adam-Guillermin, C.

2015-01-01

Highlights: • The present study aimed to evaluate the effects of gamma rays on zebrafish larvae. • Different techniques were used: gene expression, biochemistry, microscopy and macroscopical observations. • The results showed that gamma irradiation can alter embryo-larval development at several levels of organization. - Abstract: In the general context of validation of tools useful for the characterization of ecological risk linked to ionizing radiation, the effects of an external gamma irradiation were studied in zebrafish larvae irradiated for 96 h with two dose rates: 0.8 mGy/d, which is close to the level recommended to protect ecosystems from adverse effects of ionizing radiation (0.24 mGy/d) and a higher dose rate of 570 mGy/d. Several endpoints were investigated, such as mortality, hatching, and some parameters of embryo-larval development, immunotoxicity, apoptosis, genotoxicity, neurotoxicity and histological alterations. Results showed that an exposure to gamma rays induced an acceleration of hatching for both doses and a decrease of yolk bag diameter for the highest dose, which could indicate an increase of global metabolism. AChE activity decreased with the low dose rate of gamma irradiation and alterations were also shown in muscles of irradiated larvae. These results suggest that gamma irradiation can induce damages on larval neurotransmission, which could have repercussions on locomotion. DNA damages, basal ROS production and apoptosis were also induced by irradiation, while ROS stimulation index and EROD biotransformation activity were decreased and gene expression of acetylcholinesterase, choline acetyltransferase, cytochrome p450 and myeloperoxidase increased. These results showed that ionizing radiation induced an oxidative stress conducting to DNA damages. This study characterized further the modes of action of ionizing radiation in fish.

External gamma irradiation-induced effects in early-life stages of zebrafish, Danio rerio

Energy Technology Data Exchange (ETDEWEB)

Gagnaire, B., E-mail: beatrice.gagnaire@irsn.fr [Institut de Radioprotection et de Sureté Nucléaire (IRSN), PRP-ENV/SERIS/LECO, Cadarache, Saint-Paul-lez-Durance 13115 (France); Cavalié, I. [Institut de Radioprotection et de Sureté Nucléaire (IRSN), PRP-ENV/SERIS/LECO, Cadarache, Saint-Paul-lez-Durance 13115 (France); Pereira, S. [Neolys Diagnostics, Lyon 69373 (France); Floriani, M.; Dubourg, N.; Camilleri, V.; Adam-Guillermin, C. [Institut de Radioprotection et de Sureté Nucléaire (IRSN), PRP-ENV/SERIS/LECO, Cadarache, Saint-Paul-lez-Durance 13115 (France)

2015-12-15

Highlights: • The present study aimed to evaluate the effects of gamma rays on zebrafish larvae. • Different techniques were used: gene expression, biochemistry, microscopy and macroscopical observations. • The results showed that gamma irradiation can alter embryo-larval development at several levels of organization. - Abstract: In the general context of validation of tools useful for the characterization of ecological risk linked to ionizing radiation, the effects of an external gamma irradiation were studied in zebrafish larvae irradiated for 96 h with two dose rates: 0.8 mGy/d, which is close to the level recommended to protect ecosystems from adverse effects of ionizing radiation (0.24 mGy/d) and a higher dose rate of 570 mGy/d. Several endpoints were investigated, such as mortality, hatching, and some parameters of embryo-larval development, immunotoxicity, apoptosis, genotoxicity, neurotoxicity and histological alterations. Results showed that an exposure to gamma rays induced an acceleration of hatching for both doses and a decrease of yolk bag diameter for the highest dose, which could indicate an increase of global metabolism. AChE activity decreased with the low dose rate of gamma irradiation and alterations were also shown in muscles of irradiated larvae. These results suggest that gamma irradiation can induce damages on larval neurotransmission, which could have repercussions on locomotion. DNA damages, basal ROS production and apoptosis were also induced by irradiation, while ROS stimulation index and EROD biotransformation activity were decreased and gene expression of acetylcholinesterase, choline acetyltransferase, cytochrome p450 and myeloperoxidase increased. These results showed that ionizing radiation induced an oxidative stress conducting to DNA damages. This study characterized further the modes of action of ionizing radiation in fish.

Induced polygenic variability using combination treatment of gamma ...

African Journals Online (AJOL)

Induced mutation in plant improvement has been proven to be one of the alternative ways to generate new sources of genetic variation in blackgram. In this study, dry seeds of VBN 4 blackgram were treated with combination treatment of both gamma rays (400, 500 and 600 Gy) and ethyl methane sulphonate (EMS) (50, ...

Modulation of induced gamma band activity in the human EEG by attention and visual information processing.

Science.gov (United States)

Müller, M M; Gruber, T; Keil, A

2000-12-01

Here we present a series of four studies aimed to investigate the link between induced gamma band activity in the human EEG and visual information processing. We demonstrated and validated the modulation of spectral gamma band power by spatial selective visual attention. When subjects attended to a certain stimulus, spectral power was increased as compared to when the same stimulus was ignored. In addition, we showed a shift in spectral gamma band power increase to the contralateral hemisphere when subjects shifted their attention to one visual hemifield. The following study investigated induced gamma band activity and the perception of a Gestalt. Ambiguous rotating figures were used to operationalize the law of good figure (gute Gestalt). We found increased gamma band power at posterior electrode sites when subjects perceived an object. In the last experiment we demonstrated a differential hemispheric gamma band activation when subjects were confronted with emotional pictures. Results of the present experiments in combination with other studies presented in this volume are supportive for the notion that induced gamma band activity in the human EEG is closely related to visual information processing and attentional perceptual mechanisms.

Muon-induced backgrounds in the CUORICINO experiment

Energy Technology Data Exchange (ETDEWEB)

Andreotti, E.; Arnaboldi, C.; Avignone III, F. T.; Balata, M.; Bandac, I.; Barucci, M.; Beeman, J. W.; Bellini, F.; Bloxham, T.; Brofferio, C.; Bryant, A.; Bucci, C.; Canonica, L.; Capelli, S.; Carbone, L.; Carrettoni, M.; Clemenza, M.; Cremonesi, O.; Creswick, R. J.; Domizio, S. Di; Dolinski, M. J.; Ejzak, L.; Faccini, R.; Farach, H. A.; Ferri, E.; Ferroni, F.; Fiorini, E.; Foggetta, L.; Giachero, A.; Gironi, L.; Giuliani, A.; Gorla, P.; Guardincerri, E.; Gutierrez, T. D.; Haller, E. E.; Kadel, R.; Kazkaz, K.; Kraft, S.; Kogler, L.; Kolomensky, Yu. G.; Maiano, C.; Maruyama, R. H.; Martinez, C.; Martinez, M.; Mizouni, L.; Morganti, S.; Nisi, S.; Nones, C.; Norman, E. B.; Nucciotti, A.; Orio, F.; Pallavicini, M.; Palmieri, V.; Pattavina, L.; Pavan, M.; Pedretti, M.; Pessina, G.; Pirro, S.; Previtali, E.; Risegari, L.; Rosenfeld, C.; Rusconi, C.; Salvioni, C.; Sangiorgio, S.; Schaeffer, D.; Scielzo, N. D.; Sisti, M.; Smith, A. R.; Tomei, C.; Ventura, G.; Vignati, M.

2010-04-15

To better understand the contribution of cosmic ray muons to the CUORICINO background, ten plastic scintillator detectors were installed at the CUORICINO siteand operated during the final 3 months of the experiment. From these measurements, an upper limit of 0.0021 counts/(keV.kg.yr) (95percent c.l.) was obtained on the cosmicray induced background in the neutrinoless double beta decay region of interest. The measurements were also compared to Geant4 simulations.

A study of the sensitivity of an imaging telescope (GRITS) for high energy gamma-ray astronomy. Final report

International Nuclear Information System (INIS)

Yearian, M.R.

1990-08-01

When a gamma-ray telescope is placed in Earth orbit, it is bombarded by a flux of cosmic protons much greater than the flux of interesting gammas. These protons can interact in the telescope's thermal shielding to produce detectable gamma rays, most of which are vetoed. Since the proton flux is so high, the unvetoed gamma rays constitute a significant background relative to some weak sources. This background increases the observing time required to pinpoint some sources and entirely obscures other sources. Although recent telescopes have been designed to minimize this background, its strength and spectral characteristics were not previously calculated in detail. Monte Carlo calculations are presented which characterize the strength, spectrum and other features of the cosmic proton background using FLUKA, a hadronic cascade program. Several gamma-ray telescopes, including SAS-2, EGRET and the Gamma Ray Imaging Telescope System (GRITS), are analyzed, and their proton-induced backgrounds are characterized. In all cases, the backgrounds are either shown to be low relative to interesting signals or suggestions are made which would reduce the background sufficiently to leave the telescope unimpaired. In addition, several limiting cases are examined for comparison to previous estimates and calibration measurements

Simulations of the muon-induced neutron background of the EDELWEISS-II experiment for Dark Matter search

Energy Technology Data Exchange (ETDEWEB)

Horn, O M

2007-12-21

to determine the veto efficiency. Finally, the remaining background rate of muon-induced bolometer hits after applying the veto condition is approximately {gamma}{sub bg} induced background in the order of R {approx} O(10{sup 3}). As a result of this work, the sensitivity of the EDELWEISS-II experiment is in principle not limited by muoninduced background down to a WIMP-nucleon cross section in the range of 10{sup -10} pb. (orig.)

Protective effects of nelumbo nucifera against {gamma}-irradiation-induced lipid peroxidation in mice urine

Energy Technology Data Exchange (ETDEWEB)

Jeong, Il Yun; Park, Yong Dae; Jin, Caang Hyun; Choi, Dae Seong [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Lee, Hyo Jung [Gwangju Institute of Science and Technology, Gwangju (Korea, Republic of)

2009-12-15

The radioprotective effect of isoquercitrin-abundant fraction (IAF) of N. nucifera Gaertn. Ieaf extract against {gamma}-irradiation-induced oxidative stress was evaluated by the lipid peroxidation-derived aldehydes (LPDAs) as a marker for oxidative risk in mice urine, and the DNA damage using comet assay in RAW 264.7 cells. Mice that were treated with IAF (50 mg/kg) and {gamma}-irradiation showed considerably decreased LPDA levels relative to those that had received {gamma}-irradiation alone. Furthermore, pretreatment with IAF resulted in a significant decrease in the amount of DNA damage in cells. It is demonstrated that pretreatment with IAF of N. nucifera Gaertn. gives protection against irradiation-induced cellular damage.

70Z/3 Cbl induces PLC gamma 1 activation in T lymphocytes via an alternate Lat- and Slp-76-independent signaling mechanism.

Science.gov (United States)

Graham, Laurie J; Verí, Maria-Concetta; DeBell, Karen E; Noviello, Cristiana; Rawat, Rashmi; Jen, Sandy; Bonvini, Ezio; Rellahan, Barbara

2003-04-24

The oncoprotein 70Z/3 Cbl signals in an autonomous fashion or through blockade of endogenous c-Cbl, a negative regulator of signaling. The mechanism of 70Z/3 Cbl-induced signaling was investigated by comparing the molecular requirements for 70Z/3 Cbl- and TCR-induced phospholipase C gamma 1 (PLC gamma 1) activation. 70Z/3 Cbl-induced PLC gamma 1 tyrosine phosphorylation required, in addition to the PLC gamma 1 N-terminal SH2 domain, the C-terminal SH2 and SH3 domains that were dispensable for TCR-induced phosphorylation. Deletion of the leucine zipper of 70Z/3 Cbl did not eliminate 70Z/3 Cbl-induced PLC gamma 1 phosphorylation, suggesting that blockage of c-Cbl via dimerization with 70Z/3 Cbl cannot fully explain 70Z/3 Cbl activating characteristics. The complete elimination of PLC gamma 1 phosphorylation required deleting the SH3 domain-binding region of 70Z/3 Cbl, consistent with 70Z/3 Cbl binding the PLC gamma 1 SH3 domain. 70Z/3 Cbl-induced PLC gamma 1 phosphorylation required Zap-70, as for the TCR, and the tyrosine kinase binding domain of 70Z/3 Cbl, which binds Zap-70, but did not require PLC gamma 1 binding to Lat, a crucial interaction in TCR-induced PLC gamma 1 phosphorylation. Furthermore, 70Z/3 Cbl-induced activation of NFAT, a PLC gamma 1/Ca(2+)-dependent transcriptional event, required Zap-70, but was independent of Slp-76, an adapter required for TCR-induced NFAT activation. These results suggest that 70Z/3 Cbl and PLC gamma 1 form a TCR-, Lat- and Slp-76-independent complex that leads to PLC gamma 1 phosphorylation and activation.

gamma-induced modification on optical band gap of CR-39 SSNTD

International Nuclear Information System (INIS)

Zaki, M.F.

2010-01-01

effect of gamma irradiation on optical absorption of nuclear track detectors like CR-39 was studied at different absorbed doses using ultraviolet-visible (UV-VIS)spectroscopy. the existence of the peaks, their shifting and broadening as a result of gamma irradiation has been discussed. the width of the tail of localized states in the band gap (E u )was evaluated using the Urbach edge method. finally the indirect and direct band gap in pristine and gamma irradiated CR-39 have been determined. the values of indirect band gap have been found to be lower than the corresponding values of direct band gap. a decrease in the optical energy gap with increasing the gamma absorbed dose can be discussed on the basis of gamma-irradiation-induced defects in the CR-39. the correlation between optical band gap and the number of carbon atoms in a cluster with modified Tauc's equation has been discussed in case of CR-39.

Simultaneous and separate, low background counting of beta rays and gamma rays using the phoswich principle

International Nuclear Information System (INIS)

Mayhugh, M.R.; Utts, B.K.; Shoffner, B.M.

1978-01-01

A phoswich constructed using thin calcium fluoride optically coupled to a thicker sodium iodide crystal and operated with pulse shape analysis equipment can be used as an efficient low background counting assembly. Low background in the beta ray counting channel is achieved by judicious choice of pure materials in the assembly and by operating the analysis equipment so as to reject background events which occur simultaneously in the sodium iodide crystal. Careful survey of construction materials and methods has resulted in reducing beta ray counting background to 0.6 c/min for a 2-inch diameter assembly. The radioactivity of typical building materials will be discussed. A pulse shape analyzer has been constructed which provides separately adjusted time windows and separate output information for the beta ray and gamma ray channels. The dual channel capability combined with the low beta ray background reduces the sample counting time significantly for typical laboratory samples. (author)

On the omnipresent background gamma radiation of the continuous spectrum

Energy Technology Data Exchange (ETDEWEB)

Banjanac, R.; Maletić, D.; Joković, D., E-mail: yokovic@ipb.ac.rs; Veselinović, N.; Dragić, A.; Udovičić, V.; Aničin, I.

2014-05-01

The background spectrum of a germanium detector, shielded from the radiations arriving from the lower and open for the radiations arriving from the upper hemisphere, is studied by means of absorption measurements, both in a ground level and in an underground laboratory. The low-energy continuous portion of this background spectrum that peaks at around 100 keV, which is its most intense component, is found to be of very similar shape at the two locations. It is established that it is mostly due to the radiations of the real continuous spectrum, which is quite similar to the instrumental one. The intensity of this radiation is in our cases estimated to about 8000 photons/(m{sup 2}s·2π·srad) in the ground level laboratory, and to about 5000 photons/(m{sup 2}s·2π·srad) in the underground laboratory, at the depth of 25 m.w.e. Simulations by GEANT4 and CORSIKA demonstrate that this radiation is predominantly of terrestrial origin, due to environmental gamma radiations scattered off the materials that surround the detector (the “skyshine radiation”), and to a far less extent to cosmic rays of degraded energy. - Highlights: • We studied the low-energy part of continuous background spectra of germanium detectors. • The study was performed at the ground level and at the shallow underground sites. • The instrumental spectrum is due to radiations of the similar continuous spectrum. • The low-energy radiation is of both terrestrial and cosmic-ray origin. • In our study, we find that this radiation is of predominantly terrestrial origin.

Survey of Gamma Dose and Radon Exhalation Rate from Soil Surface of High Background Natural Radiation Areas in Ramsar, Iran

Directory of Open Access Journals (Sweden)

Rouhollah Dehghani

2013-09-01

Full Text Available Background: Radon is a radioactive gas and the second leading cause of death due to lung cancer after smoking. Ramsar is known for having the highest levels of natural background radiation on earth. Materials and Methods: In this research study, 50 stations of high radioactivity areas of Ramsar were selected in warm season of the year. Then gamma dose and radon exhalation rate were measured.Results: Results showed that gamma dose and radon exhalation rate were in the range of 51-7100 nSv/hr and 9-15370 mBq/m2s, respectively.Conclusion: Compare to the worldwide average 16 mBq/m2s, estimated average annual effective of Radon exhalation rate in the study area is too high.

Assessment of genetically significant doses to the Sofia population from natural gamma background

International Nuclear Information System (INIS)

Vasilev, G.; Khristova, M.

1977-01-01

Genetically significant dose to the population of Sofia city was assessed within a program covering larger urban communities in the country. Measurements were made of gamma background exposure rates in the gonadal region. Gonad doses were estimated using a screening factor of 0.73. Based on statistical data for total number of inhabitants and number of people of reproductive age, and on the mean annual gonad doses derived, calculations were made of genetically significant dose to the Sofia population. Base-line data were thus provided for an assessment of extra radiation dose resulting from occupational radiation exposure. (author)

Simulation of Neutron-Induced Prompt Gamma-ray Spectra Emitted from Fake Tungsten Gold Bar

Energy Technology Data Exchange (ETDEWEB)

Lee, K. M.; Sum, G. M. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

Fake gold bars on the market cannot be identified easily without testing because they have the same appearance as a pure gold bar. A non-destructive monitoring method is needed to avoid the trading of fake gold bars on the market. The ultimate goal of this study is to find a fake gold bar detection method using a PGAA (Prompt Gamma Activation Analysis). Using existing data, the number of neutron capture for gold and tungsten in fake tungsten gold bar was calculated and a Monte Carlo simulation for the prompt neutron-induced gamma-ray spectra was conducted. A simulation for neutron-induced prompt gamma-rays spectra when a neutron beam is irradiated onto pure and fake gold bars was successfully conducted. Through a comparison between the prompt gamma-ray spectra of the pure gold bar and those of the fake gold bar, it was concluded that the observation of prompt high-energy gamma-rays from tungsten or a reduction of prompt gamma-rays from gold can be evidence of a fake gold bar. The possibility for detecting a fake gold bar using a PGAA facility was verified.

Simulation of Neutron-Induced Prompt Gamma-ray Spectra Emitted from Fake Tungsten Gold Bar

International Nuclear Information System (INIS)

Lee, K. M.; Sum, G. M.

2016-01-01

Fake gold bars on the market cannot be identified easily without testing because they have the same appearance as a pure gold bar. A non-destructive monitoring method is needed to avoid the trading of fake gold bars on the market. The ultimate goal of this study is to find a fake gold bar detection method using a PGAA (Prompt Gamma Activation Analysis). Using existing data, the number of neutron capture for gold and tungsten in fake tungsten gold bar was calculated and a Monte Carlo simulation for the prompt neutron-induced gamma-ray spectra was conducted. A simulation for neutron-induced prompt gamma-rays spectra when a neutron beam is irradiated onto pure and fake gold bars was successfully conducted. Through a comparison between the prompt gamma-ray spectra of the pure gold bar and those of the fake gold bar, it was concluded that the observation of prompt high-energy gamma-rays from tungsten or a reduction of prompt gamma-rays from gold can be evidence of a fake gold bar. The possibility for detecting a fake gold bar using a PGAA facility was verified

[Intragenic mitotic recombination induced by ultraviolet and gamma rays in radiosensitive mutants of Saccharomyces cerevisiae yeasts].

Science.gov (United States)

Zakharov, I A; Kasinova, G V; Koval'tsova, S V

1983-01-01

The effect of UV- and gamma-irradiation on the survival and intragenic mitotic recombination (gene conversion) of 5 radiosensitive mutants was studied in comparison with the wild type. The level of spontaneous conversion was similar for RAD, rad2 and rad15, mutations xrs2 and xrs4 increasing and rad54 significantly decreasing it. The frequency of conversion induced by UV-light was greater in rad2, rad15 and xrs2 mutants and lower in xrs4, as compared to RAD. Gamma-irradiation caused induction of gene conversion with an equal frequency in RAD, rad2, rad15. Xrs2 and xrs4 mutations slightly decreased gamma-induced conversion. In rad54 mutant, UV-and gamma-induced conversion was practically absent. In the wild type yeast, a diploid strain is more resistant than a haploid, whereas in rad54 a diploid strain has the same or an increased sensitivity, as compared to a haploid strain (the "inverse ploidy effect"). This effect and also the block of induced mitotic recombination caused by rad54 indicate the presence in the yeast Saccharomyces cerevisiae of repair pathways of UV- and gamma-induced damages acting in diploid cells and realised by recombination. The data obtained as a result of many years' investigation of genetic effects in radiosensitive mutants of yeast are summarised and considered.

Simultaneous determination of exponential background and Gaussian peak functions in gamma ray scintillation spectrometers by maximum likelihood technique

International Nuclear Information System (INIS)

Eisler, P.; Youl, S.; Lwin, T.; Nelson, G.

1983-01-01

Simultaneous fitting of peaks and background functions from gamma-ray spectrometry using multichannel pulse height analysis is considered. The specific case of Gaussian peak and exponential background is treated in detail with respect to simultaneous estimation of both functions by using a technique which incorporates maximum likelihood method as well as a graphical method. Theoretical expressions for the standard errors of the estimates are also obtained. The technique is demonstrated for two experimental data sets. (orig.)

Ultrasound-induced DNA damage and signal transductions indicated by gammaH2AX

Science.gov (United States)

Furusawa, Yukihiro; Fujiwara, Yoshisada; Zhao, Qing-Li; Hassan, Mariame Ali; Ogawa, Ryohei; Tabuchi, Yoshiaki; Takasaki, Ichiro; Takahashi, Akihisa; Ohnishi, Takeo; Kondo, Takashi

2011-09-01

Ultrasound (US) has been shown to induce cancer cell death via different forms including apoptosis. Here, we report the potential of low-intensity pulsed US (LIPUS) to induce genomic DNA damage and subsequent DNA damage response. Using the ionizing radiation-induced DNA double-strand breaks (DSBs) as the positive control, we were able to observe the induction of DSBs (as neutral comet tails) and the subsequent formation of gammaH2AX-positive foci (by immunofluorescence detection) in human leukemia cells following exposure to LIPUS. The LIPUS-induced DNA damage arose most likely from the mechanical, but not sonochemical, effect of cavitation, based on our observation that the suppression of inertial cavitation abrogated the gammH2AX foci formation, whereas scavenging of free radical formation (e.g., hydroxyl radical) had no protective effect on it. Treatment with the specific kinase inhibitor of ATM or DNA-PKcs, which can phosphorylate H2AX Ser139, revealed that US-induced gammaH2AX was inhibited more effectively by the DNA-PK inhibitor than ATM kinase inhibitor. Notably, these inhibitor effects were opposite to those with radiation-induced gammH2AX. In conclusion, we report, for the first time that US can induce DNA damage and the DNA damage response as indicated by gammaH2AX was triggered by the cavitational mechanical effects. Thus, it is expected that the data shown here may provide a better understanding of the cellular responses to US.

On background radiation gradients – the use of airborne surveys when searching for orphan sources using mobile gamma-ray spectrometry

International Nuclear Information System (INIS)

Kock, Peder; Rääf, Christopher; Samuelsson, Christer

2014-01-01

Systematic background radiation variations can lead to both false positives and failures to detect an orphan source when searching using car-borne mobile gamma-ray spectrometry. The stochastic variation at each point is well described by Poisson statistics, but when moving in a background radiation gradient the mean count rate will continually change, leading to inaccurate background estimations. Airborne gamma spectrometry (AGS) surveys conducted on the national level, usually in connection to mineral exploration, exist in many countries. These data hold information about the background radiation gradients which could be used at the ground level. This article describes a method that aims to incorporate the systematic as well as stochastic variations of the background radiation. We introduce a weighted moving average where the weights are calculated from existing AGS data, supplied by the Geological Survey of Sweden. To test the method we chose an area with strong background gradients, especially in the thorium component. Within the area we identified two roads which pass through the high-variability locations. The proposed method is compared with an unweighted moving average. The results show that the weighting reduces the excess false positives in the positive background gradients without introducing an excess of failures to detect a source during passage in negative gradients. -- Highlights: • We present a simple method to account for gradients in the natural background radiation. • Gradients in the natural radiation background can be modelled at the ground level using AGS data. • The number of false positives due to background gradients can be reduced by using airborne data

The protective effect of Sambucus ebulus against lung toxicity induced by gamma irradiation in mice

Directory of Open Access Journals (Sweden)

Mohammad Karami

2015-01-01

Full Text Available The aim of present study was to investigate the potential antioxidant and lung protective activities of Sambucus ebulus (SE against toxicity induced by gamma irradiation. Hydroalcoholic extract of SE (20, 50 and 100 mg/kg was studied for its lung protective activity. Phenol and flavonoid contents of SE were determined. Male C57 mice were divided into ten groups with five mice per group. Only the first and second groups (as negative control received intraperitoneally normal saline fluid. Groups 3 to 5 received only SE extract at doses of 20 mg/kg, 50 mg/kg and 100 mg/kg intraperitoneally; three groups were repeatedly injected for 15 days as chronic group. Groups 6 to 8 received a single-dose of gamma irradiation just 2 hours before irradiation as acute group. The ninth and tenth groups (as positive control received only gamma rays. Animal was exposed whole-body to 6 Gy gamma radiation. After irradiation, tissue sections of lung parenchyma were examined by light microscope for any histopathologic changes. SE at doses 50 and 100 mg/kg improved markedly histopathological changes induced by gamma irradiation in lung. Lung protective effect of SE could be due to attention of lipid peroxidation. Our study demonstrated that SE as a natural product has a protective effect against lung toxicity induced by   gamma irradiation in animal.

Modeling of neutron induced backgrounds in x-ray framing cameras

Energy Technology Data Exchange (ETDEWEB)

Hagmann, C.; Izumi, N.; Bell, P.; Bradley, D.; Conder, A.; Eckart, M.; Khater, H.; Koch, J.; Moody, J.; Stone, G. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2010-10-15

Fast neutrons from inertial confinement fusion implosions pose a severe background to conventional multichannel plate (MCP)-based x-ray framing cameras for deuterium-tritium yields >10{sup 13}. Nuclear reactions of neutrons in photosensitive elements (charge coupled device or film) cause some of the image noise. In addition, inelastic neutron collisions in the detector and nearby components create a large gamma pulse. The background from the resulting secondary charged particles is twofold: (1) production of light through the Cherenkov effect in optical components and by excitation of the MCP phosphor and (2) direct excitation of the photosensitive elements. We give theoretical estimates of the various contributions to the overall noise and present mitigation strategies for operating in high yield environments.

The use of difference spectra with a filtered rolling average background in mobile gamma spectrometry measurements

International Nuclear Information System (INIS)

Cresswell, A.J.; Sanderson, D.C.W.

2009-01-01

The use of difference spectra, with a filtering of a rolling average background, as a variation of the more common rainbow plots to aid in the visual identification of radiation anomalies in mobile gamma spectrometry systems is presented. This method requires minimal assumptions about the radiation environment, and is not computationally intensive. Some case studies are presented to illustrate the method. It is shown that difference spectra produced in this manner can improve signal to background, estimate shielding or mass depth using scattered spectral components, and locate point sources. This approach could be a useful addition to the methods available for locating point sources and mapping dispersed activity in real time. Further possible developments of the procedure utilising more intelligent filters and spatial averaging of the background are identified.

Influence on cell proliferation of background radiation or exposure to very low, chronic gamma radiation

International Nuclear Information System (INIS)

Planel, H.; Soleilhavoup, J.P.; Tixador, R.; Richoilley, G.; Conter, A.; Croute, F.; Caratero, C.; Gaubin, Y.

1987-01-01

Investigations carried out on the protozoan Paramecium tetraurelia and the cyanobacteria Synechococcus lividus, which were shielded against background radiation or exposed to very low doses of gamma radiation, demonstrated that radiation can stimulate the proliferation of these two single-cell organisms. Radiation hormesis depends on internal factors (age of starting cells) and external factors (lighting conditions). The stimulatory effect occurred only in a limited range of doses and disappeared for dose rates higher than 50 mGy/y

Radioprotective effects of chlorogenic acid against mortality induced by gamma irradiation in mice

International Nuclear Information System (INIS)

Seyed Jalal Hosseinimehr; Amirhossein Ahmadi; Shahram Akhlaghpoor; Tehran University of Medical Sciences, Tehran

2007-01-01

Complete text of publication follows. The radioprotective effects of the naturally occurring compound chlorogenic acid has been investigated against mortality induced by gamma irradiation in mice. Chlorogenic acid administrated at single doses of 100, 200 and 400 mg/kg 1 and 24 h prior to lethal dose of gamma irradiation (8.5 Gy). At 30 days after treatment, the percentage of animal survival in each group was: control, 20%; 100 mg/kg, 20% and 15%; 200 mg/kg, 45% and 15%; 400 mg/kg, 25% and 35% for 1 h and 24 h treatment prior gamma irradiation, respectively. Percentage of survival increased in animal treated with this agent at 200 mg/kg at 1 h statistically compared with irradiated alone group. Other doses of chlorogenic acid have not showed any enhanced survival at 1 and 24 h before irradiation. Chlorogenic acid exhibited concentration-dependent activity on 1, 1-diphenyl 2-picrylhydrazyl free radical to show strong antioxidant activity. It appeared that chlorogenic acid with antioxidant activity reduced mortality induced by gamma irradiation.

A dual neutron/gamma source for the Fissmat Inspection for Nuclear Detection (FIND) system.

Energy Technology Data Exchange (ETDEWEB)

Doyle, Barney Lee (Sandia National Laboratories, Albuquerque, NM); King, Michael; Rossi, Paolo (Sandia National Laboratories, Albuquerque, NM); McDaniel, Floyd Del (Sandia National Laboratories, Albuquerque, NM); Morse, Daniel Henry; Antolak, Arlyn J.; Provencio, Paula Polyak (Sandia National Laboratories, Albuquerque, NM); Raber, Thomas N.

2008-12-01

Shielded special nuclear material (SNM) is very difficult to detect and new technologies are needed to clear alarms and verify the presence of SNM. High-energy photons and neutrons can be used to actively interrogate for heavily shielded SNM, such as highly enriched uranium (HEU), since neutrons can penetrate gamma-ray shielding and gamma-rays can penetrate neutron shielding. Both source particles then induce unique detectable signals from fission. In this LDRD, we explored a new type of interrogation source that uses low-energy proton- or deuteron-induced nuclear reactions to generate high fluxes of mono-energetic gammas or neutrons. Accelerator-based experiments, computational studies, and prototype source tests were performed to obtain a better understanding of (1) the flux requirements, (2) fission-induced signals, background, and interferences, and (3) operational performance of the source. The results of this research led to the development and testing of an axial-type gamma tube source and the design/construction of a high power coaxial-type gamma generator based on the {sup 11}B(p,{gamma}){sup 12}C nuclear reaction.

Machine Induced Background with BCM1F 2015

CERN Document Server

CMS Collaboration

2015-01-01

BCM1F provides information on the condition of the beam and ensures that the inner detector occupancy is sufficiently low for data-taking. Measurements of the machine induced background for beam 1 (BKGD1) and beam 2 (BKGD2) are displayed in the CMS and LHC control room. The background data correlates the with collimator settings as well as with the vacuum pressure.

Influence Of Ginger (Zingiber Officinale) Supplementation Against GAMMA Rays Induced Immunosuppression In Male Rats

International Nuclear Information System (INIS)

Mangood, S.A.; Kassab, F.M.A.

2013-01-01

The influence of ginger (Zingiber officinale) supplementation against gamma rays-induced immunosuppression in male albino rats was investigated in the present study. Twenty four male albino rats were divided into four equal groups; control group (receiving no treatment), ginger group where the rats received ginger orally at a dose of 15 g/rat/day for 120 consecutive days, gamma radiation group which subjected to a single 6 Gy whole body gamma radiation and gamma radiation plus ginger group where each rat after taking daily 15 g of ginger for 120 consecutive days was subjected to 6 Gy whole body irradiation. Complete blood pictures and immunoglobulin G (IgG) and M (IgM) were estimated and spleen tissue was also examined histologically. The data obtained revealed that exposure to 6 Gy of gamma radiation caused significant decrease in the body weight, spleen weight, IgG, IgM, erythroide and leucoid elements and produced histological damage in spleen tissue. On the other hand, ginger as a protective agent, caused significant amelioration in the changes produced by irradiation especially immunoglobulins leading to the conclusion that ginger supplementation for 120 days caused modulation of the humoral immune response in irradiated rats. In conclusion, these findings indicated that ginger has the regulatory effect against gamma rays-induced immunosuppression.

IFN-gamma-induced chemokines synergize with pertussis toxin to promote T cell entry to the central nervous system

DEFF Research Database (Denmark)

Millward, Jason M; Caruso, Maria; Campbell, Iain L

2007-01-01

Inflammation of the CNS, which occurs during multiple sclerosis and experimental autoimmune encephalomyelitis, is characterized by increased levels of IFN-gamma, a cytokine not normally expressed in the CNS. To investigate the role of IFN-gamma in CNS, we used intrathecal injection of a replication......-defective adenovirus encoding murine IFN-gamma (AdIFNgamma) to IFN-gamma-deficient (GKO) mice. This method resulted in stable, long-lived expression of IFN-gamma that could be detected in cerebrospinal fluid using ELISA and Luminex bead immunoassay. IFN-gamma induced expression in the CNS of message and protein...... was predominantly localized to meningeal and ependymal cells, and was also seen in astrocytes and microglia. IFN-gamma-induced chemokine expression did not lead to inflammation. However, when pertussis toxin was given i.p. to mice infected with the IFN-gamma vector, there was a dramatic increase in the number of T...

Man bhawan - new chrysanthemum cultivar induced by gamma irradiation

International Nuclear Information System (INIS)

Datta, S.K.

1987-01-01

Attempts were made to find out the biochemical difference between two gamma ray induced chrysanthemum cultivars, 'Flirt' and 'Man Bhawan' by thin layer chromatographic and spectrophotometric analysis of pigments. The analysis were done from florets extracts of original cv., 'Flirt' and mutant 'Man Bhawan' at full bloom stage and also at fading of 'Man Bhawan'. (author)

Gamma-induced defect production in ZrO2-Y2O3 crystals with different defectiveness

International Nuclear Information System (INIS)

Ashurov, M.Kh.; Amonov, M.Z.; Rakov, A.F.

2002-01-01

Full text: The defectiveness degree of ZrO 2 -Y 2 O 3 crystals depends on stabilizer concentration. The work is aimed at study gamma-induced defect production in crystals with different concentration of stabilizer and defects generated by neutron irradiation. Absorption spectra were measured with Specord M-40. It was found, that after gamma-irradiation of as-grown crystals up to some dose the intensity of absorption band at 420 nm reaches the maximum level of saturation. The dose of saturation depends of the concentration of stabilizer. It means that gamma-radiation does not produce any additional defects of structure. The oxygen vacancies existing in as-grown crystals are filled by the radiation induced electrons. Since the number of oxygen vacancies depends on the stabilizer concentration, then all these vacancies can be occupied by electrons at different gamma-doses. In crystals pre-irradiated with different neutron fluences followed by gamma-irradiation, the intensity of absorption bands at 420 and 530 nm increases in two stages. The gamma-dose of the second stage beginning decreases as the neutron fluence grows. The first stage of the absorption increase is due to developing of vacancies existing in as-grown crystals. The second stage is caused by generation of additional vacancies as the result of non-radiative exciton decay near the existing structure damages. The decrease of the gamma-dose, when the second stage of vacancy accumulation begins, results from the neutron induced structure damage degree

Gamma-ray-induced changes in the synthesis of tomato pericarp protein

International Nuclear Information System (INIS)

Ferullo, J.M.; Nespoulous, L.; Triantaphylides, C.

1994-01-01

The application of massive doses of gamma rays (1–8 kGy) to mature green cherry-tomato fruits led to a transient fall in pericarp tissue protein metabolism within 6h. A separate 3 kGy treatment resulted in the appearance of certain transcripts and proteins, and a reduction in the abundance of others. At the same dose, protein synthesis regained the control level within 24 h, and in addition a new set of proteins was induced. Gamma-induced proteins (referred to as GIPs) were divided into three groups, depending on the time-course of their induction. Group 1 GIPs were synthesized only during the first few hours following treatment, whereas group 2 GIPs were synthesized for at least 48 h. Group 3 GIPs were progressively induced when the control level of synthesis was restored. These results demonstrated that, despite its deleterious effects on DNA and cell structures, irradiation induced an active response in plant tissue. Comparative experiments suggest that the majority of group 1 GIPs might belong to the heat shock protein family. GIPs might play a role in the protection and repair of cellular structures, or may be implicated in physiological disorders triggered by irradiation. (author)

What's that sound? Matches with auditory long-term memory induce gamma activity in human EEG.

Science.gov (United States)

Lenz, Daniel; Schadow, Jeanette; Thaerig, Stefanie; Busch, Niko A; Herrmann, Christoph S

2007-04-01

In recent years the cognitive functions of human gamma-band activity (30-100 Hz) advanced continuously into scientific focus. Not only bottom-up driven influences on 40 Hz activity have been observed, but also top-down processes seem to modulate responses in this frequency band. Among the various functions that have been related to gamma activity a pivotal role has been assigned to memory processes. Visual experiments suggested that gamma activity is involved in matching visual input to memory representations. Based on these findings we hypothesized that such memory related modulations of gamma activity exist in the auditory modality, as well. Thus, we chose environmental sounds for which subjects already had a long-term memory (LTM) representation and compared them to unknown, but physically similar sounds. 21 subjects had to classify sounds as 'recognized' or 'unrecognized', while EEG was recorded. Our data show significantly stronger activity in the induced gamma-band for recognized sounds in the time window between 300 and 500 ms after stimulus onset with a central topography. The results suggest that induced gamma-band activity reflects the matches between sounds and their representations in auditory LTM.

Measurable difference in Cherenkov light between gamma and hadron induced EAS

Energy Technology Data Exchange (ETDEWEB)

Cabot, H.; Meynadier, Ch. [Universite de Perpignan, Groupe de Physique Fondamentale, Perpignan (France); Sobczynska, D. [Experimental Physics Department, University of Lodz, Lodz (Poland); Szabelska, B. [Soltan Institute for Nuclear Studies, Lodz (Poland); Szabelski, J. [Universite de Perpignan, Groupe de Physique Fondamentale, Perpignan (France)]|[Soltan Institute for Nuclear Studies, Lodz (Poland); Wibig, T. [Experimental Physics Department, University of Lodz, Lodz (Poland)

1997-12-31

We describe the possibly measurable difference in the Cherenkov light component of EAS induced by en electromagnetic particle (i.e. e{sup +}, e{sup -} or {gamma}) and induced by a hadron (i.e. proton or heavier nuclei) in TeV range. The method can be applied in experiments which use wavefront sampling method of EAS Cherenkov light detection (e.g. THEMISTOCLE, ASGAT). (author) 16 refs, 9 figs

The protective role of Gamma-Tocopherol and zinc cysteine against oxidative stress induced by gamma irradiation in albino rats

International Nuclear Information System (INIS)

Anis, L.M.

2004-01-01

The present study aimed to evaluate the capability of α tocopherol (naturally occurring antioxidant) and zinc cysteine against radiation induced oxidative stress. α Tocopherol was dissolved in corn oil and g, to the animals for ten successive days at a dose of 20 mg/kg b weight/day. Zinc cysteine was delivered to rats via intraperitoneal inject at a concentration of 25 mg/kg body weight/day for two successive days, rats were exposed to whole body gamma irradiation at a dose level of Gy. The activities of super oxide dismutase (SOD) and catalase and also concentrations of reduced glutathione (GSH) and malonaldehyde (Mi . were determined in the blood. The levels of metallothionein, zinc and copper were estimated in the serum, liver and kidney of the tested animals. The obtained results revealed that administration of a-tocopherol and zinc cysteine before gamma radiation exposure diminish significantly the decrease in blood SOD and catalase activities as compared to untreated irradiated rats. Also, the decrease in blood GSH concentration was less manifested and the decrease in the level of MDA was significant. The pre-gamma irradiation administration of zinc cysteine induced significant changes in the levels of metallothionein compared to both a-tocopherol supplemented and gamma irradiated rat groups. The amelioration occurred in the levels of zinc and copper postulated the positive role of vitamin E and zinc cysteine in alleviating all the levels of these elements

Energy- and time-resolved detection of prompt gamma-rays for proton range verification.

Science.gov (United States)

Verburg, Joost M; Riley, Kent; Bortfeld, Thomas; Seco, Joao

2013-10-21

In this work, we present experimental results of a novel prompt gamma-ray detector for proton beam range verification. The detection system features an actively shielded cerium-doped lanthanum(III) bromide scintillator, coupled to a digital data acquisition system. The acquisition was synchronized to the cyclotron radio frequency to separate the prompt gamma-ray signals from the later-arriving neutron-induced background. We designed the detector to provide a high energy resolution and an effective reduction of background events, enabling discrete proton-induced prompt gamma lines to be resolved. Measuring discrete prompt gamma lines has several benefits for range verification. As the discrete energies correspond to specific nuclear transitions, the magnitudes of the different gamma lines have unique correlations with the proton energy and can be directly related to nuclear reaction cross sections. The quantification of discrete gamma lines also enables elemental analysis of tissue in the beam path, providing a better prediction of prompt gamma-ray yields. We present the results of experiments in which a water phantom was irradiated with proton pencil-beams in a clinical proton therapy gantry. A slit collimator was used to collimate the prompt gamma-rays, and measurements were performed at 27 positions along the path of proton beams with ranges of 9, 16 and 23 g cm(-2) in water. The magnitudes of discrete gamma lines at 4.44, 5.2 and 6.13 MeV were quantified. The prompt gamma lines were found to be clearly resolved in dimensions of energy and time, and had a reproducible correlation with the proton depth-dose curve. We conclude that the measurement of discrete prompt gamma-rays for in vivo range verification of clinical proton beams is feasible, and plan to further study methods and detector designs for clinical use.

Particle transport simulation for spaceborne, NaI gamma-ray spectrometers

International Nuclear Information System (INIS)

Dyer, C.S.; Truscott, P.R.; Sims, A.J.; Comber, C.; Hammond, N.D.A.

1988-11-01

Radioactivity induced in detectors by protons and secondary neutrons limits the sensitivity of spaceborne gamma-ray spectrometers. Three dimensional Monte Carlo transport codes have been employed to simulate particle transport of cosmic rays and inner-belt protons in various representations of the Gamma Ray Observatory Spacecraft and the Oriented Scintillation Spectrometer Experiment. Results are used to accurately quantify the contributions to the radioactive background, assess shielding options and examine the effect of detector and space-craft orientation in anisotropic trapped proton fluxes. (author)

Modifications induced by gamma irradiation to Makrofol polymer nuclear track detector

Directory of Open Access Journals (Sweden)

A. Tayel

2015-03-01

Full Text Available The aim of the present study was extended from obtaining information about the interaction of gamma rays with Makrofol DE 7-2 track detector to introduce the basis that can be used in concerning simple sensor for gamma irradiation and bio-engineering applications. Makrofol polymer samples were irradiated with 1.25 MeV 60Co gamma radiations at doses ranging from 20 to 1000 kG y. The modifications of irradiated samples so induced were analyzed using UV–vis spectrometry, photoluminescence spectroscopy, and the measurements of Vickers’ hardness. Moreover, the change in wettability of irradiated Makrofol was investigated by the contact angle determination of the distilled water. UV–vis spectroscopy shows a noticeable decrease in the energy band gap due to gamma irradiation. This decrease could be attributed to the appearance of a shift to UV spectra toward higher wavelength region after irradiation. Photoluminescence spectra reveal a remarkable change in the integrated photoluminescence intensity with increasing gamma doses, which may be resulted from some matrix disorder through the creation of some defected states in the irradiated polymer. The hardness was found to increase from 4.78 MPa for the unirradiated sample to 23.67 MPa for the highest gamma dose. The contact angle investigations show that the wettability of the modified samples increases with increasing the gamma doses. The result obtained from present investigation furnishes evidence that the gamma irradiations are a successful technique to modify the Makrofol DE 7-2 polymer properties to use it in suitable applications.

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

International Nuclear Information System (INIS)

Saito, Takeshi; Fujii, Noriko

2014-01-01

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. - Highlights: • Gamma radiation dose-dependently increases degradation levels of α-linolenic acid. • Gamma radiation dose-dependently increases peroxidation levels of α-linolenic acid. • An optimum concentration of carotenoids inhibits degradation of α-linolenic acid. • Relatively low concentrations of carotenoids promote degradation of α-linolenic acid. • Carotenoids do not affect the peroxidation level of α-linolenic acid

Involvement of mismatch repair proteins in adaptive responses induced by N-methyl-N'-nitro-N-nitrosoguanidine against {gamma}-induced genotoxicity in human cells

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, Ayumi; Sakamoto, Yasuteru; Masumura, Kenichi; Honma, Masamitsu [Division of Genetics and Mutagenesis, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501 (Japan); Nohmi, Takehiko, E-mail: nohmi@nihs.go.jp [Division of Genetics and Mutagenesis, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501 (Japan)

2011-08-01

Highlights: {yields} Health effects of radiation should be evaluated in combination with chemicals. {yields} Here, we show that MNNG suppresses radiation-induced genotoxicity in human cells. {yields} Mismatch repair proteins play critical roles in the apparent adaptive responses. {yields} Chemical exposure may modulate radiation-induced genotoxicity in humans. - Abstract: As humans are exposed to a variety of chemical agents as well as radiation, health effects of radiation should be evaluated in combination with chemicals. To explore combined genotoxic effects of radiation and chemicals, we examined modulating effects of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), a direct-acting methylating agent, against genotoxicity of {gamma}-radiation. Human lymphoblastoid TK6 cells and its mismatch-deficient derivative, i.e., MT1 cells, were treated with MNNG for 24 h before they were exposed to {gamma}-irradiation at a dose of 1.0 Gy, and the resulting genotoxicity was examined. In TK6 cells, the pretreatments with MNNG at low doses suppressed frequencies of the thymidine kinase (TK) gene mutation and micronucleus (MN) formation induced by {gamma}-irradiation and thus the dose responses of TK and MN assays were U-shaped along with the pretreatment doses of MNNG. In contrast, the genotoxic effects of MNNG and {gamma}-irradiation were additive in MT1 cells and the frequencies of TK mutations and MN induction increased along with the doses of MNNG. Apoptosis induced by {gamma}-radiation was suppressed by the pretreatments in TK6 cells, but not in MT1 cells. The expression of p53 was induced and cell cycle was delayed at G2/M phase in TK6, but not in MT1 cells, by the treatments with MNNG. These results suggest that pretreatments of MNNG at low doses suppress genotoxicity of {gamma}-radiation in human cells and also that mismatch repair proteins are involved in the apparent adaptive responses.

Gamma irradiation-induced variation in carrots (Daucus carota L.)

International Nuclear Information System (INIS)

Al-Safadi, B.; Simon, P.W.

1996-01-01

Carrot tissue cultures, germinating seed, and dry seed were exposed to gamma radiation. Irradiation accelerated germination of carrot seed in the M1 generation at low doses (0.5 and 1 krad), whereas higher doses delayed germination. A high negative correlation was observed between dose and survival of plants after seed irradiation. Plant size and root weight were 20% to 35% greater than control plants after seeds, but not tissue cultures, were exposed to low doses of gamma irradiation. Higher doses reduced M1 plant size by 50% in germinating seed and tissue culture treatments but less for the dry seed treatment. Seed production decreased while phenotypic variation of M1 plants increased with increasing gamma ray dosage. Root weight and total dissolved solids were highly variable in M2 families. Less variation was observed in total carotene content and none was seen in sugar type (reducing vs. non reducing sugars). Induced variation in root color and root shape was also observed. Irradiation of germinating seed and tissue cultures yielded more M2 variation than irradiation of dry seed. Putative point mutations were not observed. Unirradiated carrot tissue cultures did not yield significant M2 somaclonal variation. Average root weight of M2 plants increased with increasing gamma ray dosage, especially for the dry seed treatment

Gamma irradiation induced variation in carrots (Daucus Carota L.)

International Nuclear Information System (INIS)

Al-Safady, B.; Simon, P.W.

1999-01-01

Carrot tissue cultures, germinating seed, and dry seed were exposed to gamma radiation. Irradiation accelerated germination of carrot seed in the M 1 generation at low doses (0.5 and 1 krad), whereas higher doses delayed germination. A high negative correlation was observed between dose and survival of plants after seed irradiation. Plant size and root weight were 20% to 35% greater than control plants after seeds, but not tissue culture, were exposed to low doses of gamma irradiation. Higher doses reduced M 1 plant size by > 50% in germinating seed and tissue culture treatments but less for the dry seed treatment. Seed production decreased while phenotypic variation of M 1 plants increased with increasing gamma ray dosage. Root weight and total dissolved solids were highly variable in M 2 families. Less variation was observed in total carotene content and none was seen in sugar type [reducing vs. non reducing sugars]. Induced variation in root color and rot shape was also observed. Irradiation of germinating seed and tissue cultures yielded more M 2 variation than irradiation of dry seed. Putative point mutations were not observed. Unirradiated carrot tissue cultures did not yield significant M 2 somaclonal variation. Average root weight of M 2 plants increased with increasing gamma ray dosage, especially for the dry seed treatment (Author)

Design and environmental applications of an ultra-low-background, high-efficiency intrinsic Ge gamma-ray spectrometer

International Nuclear Information System (INIS)

Wogman, N.A.

1981-04-01

A coincidence shielded intrinsic Ge gamma-ray spectrometer incorporating a 25% efficient, high resolution coaxial diode inside a 30 cm diameter NaI(Tl) shield is described. System design eliminates the major cause of background and minimizes cosmic-ray created background events through the use of electronic means. The system provides a peak-to-Compton ratio of greater than 1000 to 1 for 137 Cs and high sensitivity for both low and high level radionuclide measurements. At 3 MeV the background is 0.000058 counts per minute per keV. At 1 MeV it is 0.00048 counts per minute per keV, and at 0.5 MeV it is 0.0045 counts per minute per keV. Traces of primordial radionuclides create background events such as at 2.614 MeV (0.016 counts per minute total peak area), at 2.448 MeV (0.0058 counts per minute per total peak area), and at 2.204 MeV (0.023 counts per minute per total peak area). The system is discussed with respect to its background design, methods to improve its design, and its application to measurements of neutron activated and environmental materials problems

THE ORIGIN OF THE COSMIC GAMMA-RAY BACKGROUND IN THE MeV RANGE

International Nuclear Information System (INIS)

Ruiz-Lapuente, Pilar; The, Lih-Sin; Hartmann, Dieter H.; Ajello, Marco; Canal, Ramon; Röpke, Friedrich K.; Ohlmann, Sebastian T.; Hillebrandt, Wolfgang

2016-01-01

There has been much debate about the origin of the diffuse γ-ray background in the MeV range. At lower energies, AGNs and Seyfert galaxies can explain the background, but not above ≃0.3 MeV. Beyond ∼10 MeV blazars appear to account for the flux observed. That leaves an unexplained gap for which different candidates have been proposed, including annihilations of WIMPS. One candidate is Type Ia supernovae (SNe Ia). Early studies concluded that they were able to account for the γ-ray background in the gap, while later work attributed a significantly lower contribution to them. All those estimates were based on SN Ia explosion models that did not reflect the full 3D hydrodynamics of SN Ia explosions. In addition, new measurements obtained since 2010 have provided new, direct estimates of high-z SN Ia rates beyond z ∼ 2. We take into account these new advances to see the predicted contribution to the gamma-ray background. We use here a wide variety of explosion models and a plethora of new measurements of SN Ia rates. SNe Ia still fall short of the observed background. Only for a fit, which would imply ∼150% systematic error in detecting SN Ia events, do the theoretical predictions approach the observed fluxes. This fit is, however, at odds at the highest redshifts with recent SN Ia rate estimates. Other astrophysical sources such as flat-spectrum radio quasars do match the observed flux levels in the MeV regime, while SNe Ia make up to 30%–50% of the observed flux

THE ORIGIN OF THE COSMIC GAMMA-RAY BACKGROUND IN THE MeV RANGE

Energy Technology Data Exchange (ETDEWEB)

Ruiz-Lapuente, Pilar [Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, c/. Serrano 121, E-28006, Madrid (Spain); The, Lih-Sin; Hartmann, Dieter H.; Ajello, Marco [Department of Physics and Astronomy, Clemson University, Clemson, SC 29634 (United States); Canal, Ramon [Institut de Ciències del Cosmos (UB-IEEC), c/. Martí i Franqués 1, E-08028, Barcelona (Spain); Röpke, Friedrich K.; Ohlmann, Sebastian T. [Institute of Theoretical Physics and Astrophysics, University of Würzburg, D-97074, Würzburg (Germany); Hillebrandt, Wolfgang [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching bei München (Germany)

2016-04-01

There has been much debate about the origin of the diffuse γ-ray background in the MeV range. At lower energies, AGNs and Seyfert galaxies can explain the background, but not above ≃0.3 MeV. Beyond ∼10 MeV blazars appear to account for the flux observed. That leaves an unexplained gap for which different candidates have been proposed, including annihilations of WIMPS. One candidate is Type Ia supernovae (SNe Ia). Early studies concluded that they were able to account for the γ-ray background in the gap, while later work attributed a significantly lower contribution to them. All those estimates were based on SN Ia explosion models that did not reflect the full 3D hydrodynamics of SN Ia explosions. In addition, new measurements obtained since 2010 have provided new, direct estimates of high-z SN Ia rates beyond z ∼ 2. We take into account these new advances to see the predicted contribution to the gamma-ray background. We use here a wide variety of explosion models and a plethora of new measurements of SN Ia rates. SNe Ia still fall short of the observed background. Only for a fit, which would imply ∼150% systematic error in detecting SN Ia events, do the theoretical predictions approach the observed fluxes. This fit is, however, at odds at the highest redshifts with recent SN Ia rate estimates. Other astrophysical sources such as flat-spectrum radio quasars do match the observed flux levels in the MeV regime, while SNe Ia make up to 30%–50% of the observed flux.

Improvement effect of gamma-irradiated complex leaf extract of date plum, persimmon and mulberry on UVB-induced skin damage

Energy Technology Data Exchange (ETDEWEB)

Choi, Ji Won; Cho, Byoung Ok; Che, Denis Nchang; Shin, Jae Young; Fang, Chong Zhou; Jang, Seon Il [Jeonju University, Jeonju (Korea, Republic of)

2016-11-15

This study was conducted to evaluate the improvement effect of gamma-irradiated complex leaf extract of Date Plum, Persimmon and Mulberry (γ-DPME) on UVB induced skin damage. The samples were gamma irradiated at doses of 10 kGy. γ-DPME treatment tended to decrease UVB-induced immune cell infiltration and erthyderma index than the groups treated with non-gamma-irradiated DPME (n-DPME) and L-ascobic acid (AA). In addition, γ-DPME treatment significantly decreased skin thickness, melanin index and mast cell infiltration in UVB-irradiated skin. Moreover, γ-DPME treatment significantly decreased the compound 48/80-induced scratching behavior and immune cell infiltration than n-DPME group. These results show that gamma irradiation can be used to increase the physiological activities of DPME.

The split-sting trait in Apis mellifera induced by cobalt 60 gamma radiation

International Nuclear Information System (INIS)

Silva, Vera Lucia Maciel

1993-01-01

The Split-Sting (SS) trait in honey bees, induced by gamma radiation, was discovered by Soares (1975). Bees with this trait are unable to sting, because the parts that compose the sting are separated. Many studies have been done in order to understand this new mutation. We studied the effect of gamma radiation on induction of the SS trait in feral bee strains. The doses were applied to the phase of larvae of queens with 5 days old. The following results were obtained: all doses of radiation induced the SS trait. There was an increase in the percentage of queens with SS with an increase in radiation dose; the SS trait induced by radiation is probably phenocopy; SS bees were observed in nature; increase of the rate mortality and malformation with an increase in radiation dose. (author)

Measurements of neutron-induced capture and fission reactions on $^{235}$ U: cross sections and ${\\alpha}$ ratios, photon strength functions and prompt ${\\gamma}$-ray from fission

CERN Multimedia

We propose to measure the neutron-induced capture cross section of the fissile isotope $^{235}$U using a fission tagging set-up. This new set-up has been tested successfully in 2010 and combines the n_TOF 4${\\pi}$ Total Absorption Calorimeter (TAC) with MicroMegas (MGAS) fission detectors. It has been proven that such a combination of detectors allows distinguishing with very good reliability the electromagnetic cascades from the capture reactions from dominant ${\\gamma}$-ray background coming from the fission reactions. The accurate discrimination of the fission background is the main challenge in the neutron capture cross section measurements of fissile isotopes. The main results from the measurement will be the associated capture cross section and ${\\alpha}$ ratio in the resolved (0.3-2250 eV) and unresolved (2.25-30 keV) resonance regions. According to the international benchmarks and as it is mentioned in the NEA High Priority Request List (HPRL), the 235U(n,${\\gamma}$) cross section is of utmost impo...

Proceedings of the First International Induced Gamma Emission Workshop

International Nuclear Information System (INIS)

Popescu, I.I.; Ur, C.A.

1999-01-01

The proceedings of the First International Induced Gamma Emission Workshop held on August 16-20, 1997 in Predeal, Romania contain 40 communications. These are bunched in the following 7 sections: 1. Opening session (8 papers); 2. Theory and Modelling (7 papers); 3. Pump Mechanisms (6 papers); 4. Pump Sources (3 papers); 5. Collective Effects (8 papers); 6. Nuclear Isomers (3 papers); 7. Moessbauer Effect (5 papers)

Improved amylose content of rice (IR72) induced through gamma radiation

International Nuclear Information System (INIS)

Barrida, Adelaida C.; Rivera, Faye G.; Manrique, Mary Jayne C.; Dimaano, Arvin O.; Costimiano, Eduardo C.

2015-01-01

In general grain quality and quality preferences vary across rice growing countries and regions. Filipinos preferres translucent, well milled, long grain rice with aroma and minimal broken grains which is soft after cooling. The amylose content of rice starch is a major eating quality factor. The aim of this study is to develop rice mutants with good eating quality and low to intermediate amylose content through induced mutation using gamma radiation. Low to intermediate amylose content in rice were identified and selected among the advance generation lines irradiated with 200 and 300Gy dose of gamma radiation. Screening was done using qualitative method (Iodine staining method). Selected lines were analyzed quantitatively, to determine the percent amylose content. Percent amylose were group to several categories where; 0-6% is waxy, 6-12% is very low, 12-18% is low, 18-24% is intermediate and >25% is high. Results were further confirmed using molecular marker technique by looking at the waxy gene which code for granule bound starch synthase I (GBSSI) and controls amylose content in rice. Among the 30 lines selcted and anaylzes, 2 lines were confirmed to have a gene base mutation with a low to intermediate amylose content. Thus, induced mutation using gamma radiation has successfully improved amylose content in rice (IR72). (author)

Constraints on decaying dark matter from the extragalactic gamma-ray background

International Nuclear Information System (INIS)

Ando, Shin'ichiro

2015-02-01

If dark matter is unstable and the mass is within GeV-TeV regime, its decays produce high-energy photons that give contribution to the extragalactic gamma-ray background (EGRB). We constrain dark matter decay by analyzing the 50-month EGRB data measured with Fermi satellite, for different decay channels motivated with several supersymmetric scenarios featuring R-parity violation. We adopt the latest astrophysical models for various source classes such as active galactic nuclei and star-forming galaxies, and take associated uncertainties properly into account. The lower limits for the lifetime are very stringent for a wide range of dark matter mass, excluding the lifetime shorter than 10 28 s for mass between a few hundred GeV and ∝1TeV, e.g., for b anti b decay channel. Furthermore, most dark matter models that explain the anomalous positron excess are also excluded. These constraints are robust, being little dependent on astrophysical uncertainties, unlike other probes such as Galactic positrons or anti-protons.

Gamma knife surgery-induced ependymoma after the treatment of meningioma - a case report.

Science.gov (United States)

Wang, Ke; Pan, Li; Che, Xiaoming; Lou, Meiqing

2012-01-01

Gamma knife surgery is widely used for a number of neurological disorders. However, little is known about its long-term complications such as carcinogenic risks. Here, we present a case of a radiosurgery-induced ependymoma by gamma knife surgery for the treatment of a spinal meningioma in a 7-year-old patient. In light of reviewing the previous reports, we advocate high caution in making young patients receive this treatment.

Gamma ray induced diversity in restorer line of cotton (Gossypium Hirsutum)

International Nuclear Information System (INIS)

Mehetre, S.S.; Patil, V.R.; Surana, P.P.

2000-01-01

Looking to the limitation of very few restorers available in cotton a diversification of available restorer line was undertaken by gamma irradiation. The four hundred individual plants selected from individual M 2 families were crossed with CMS lines. Out of which 12 plants restored fertility in CMS lines and their F 1 's with CMS produced more heterotic hybrids than their checks (control). The results indicated that sufficient variability can be induced with the help of gamma rays and the diversification of restorers is possible within a short period with simultaneous improvement in either one or two characters. (author)

INDUCED EEG GAMMA OSCILLATION ALIGNMENT IMPROVES DIFFERENTIATION BETWEEN AUTISM AND ADHD GROUP RESPONSES IN A FACIAL CATEGORIZATION TASK.

Science.gov (United States)

Gross, Eric; El-Baz, Ayman S; Sokhadze, Guela E; Sears, Lonnie; Casanova, Manuel F; Sokhadze, Estate M

2012-01-01

INTRODUCTION: Children diagnosed with an autism spectrum disorder (ASD) often lack the ability to recognize and properly respond to emotional stimuli. Emotional deficits also characterize children with attention deficit/hyperactivity disorder (ADHD), in addition to exhibiting limited attention span. These abnormalities may effect a difference in the induced EEG gamma wave burst (35-45 Hz) peaked approximately 300-400 milliseconds following an emotional stimulus. Because induced gamma oscillations are not fixed at a definite point in time post-stimulus, analysis of averaged EEG data with traditional methods may result in an attenuated gamma burst power. METHODS: We used a data alignment technique to improve the averaged data, making it a better representation of the individual induced EEG gamma oscillations. A study was designed to test the response of a subject to emotional stimuli, presented in the form of emotional facial expression images. In a four part experiment, the subjects were instructed to identify gender in the first two blocks of the test, followed by differentiating between basic emotions in the final two blocks (i.e. anger vs. disgust). EEG data was collected from ASD (n=10), ADHD (n=9), and control (n=11) subjects via a 128 channel EGI system, and processed through a continuous wavelet transform and bandpass filter to isolate the gamma frequencies. A custom MATLAB code was used to align the data from individual trials between 200-600 ms post-stimulus, EEG site, and condition by maximizing the Pearson product-moment correlation coefficient between trials. The gamma power for the 400 ms window of maximum induced gamma burst was then calculated and compared between subject groups. RESULTS AND CONCLUSION: Condition (anger/disgust recognition, gender recognition) × Alignment × Group (ADHD, ASD, Controls) interaction was significant at most of parietal topographies (e.g., P3-P4, P7-P8). These interactions were better manifested in the aligned data set

Gamma ray induced decomposition of lanthanide nitrates

International Nuclear Information System (INIS)

Joshi, N.G.; Garg, A.N.

1992-01-01

Gamma ray induced decomposition of the lanthanide nitrates, Ln(NO 3 ) 3 .xH 2 O where Ln=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Tm and Yb has been studied at different absorbed doses up to 600 kGy. G(NO 2 - ) values depend on the absorbed dose and the nature of the outer cation. It has been observed that those lanthanides which exhibit variable valency (Ce and Eu) show lower G-values. An attempt has been made to correlate thermal and radiolytic decomposition processes. (author). 20 refs., 3 figs., 1 tab

Spectral evolution of active galactic nuclei: A unified description of the X-ray and gamma-ray backgrounds

International Nuclear Information System (INIS)

Letter, D.; Boldt, E.

1982-01-01

A model for spectral evolution is presented whereby active galactic nuclei (AGN) of the type observed individually have emerged from an earlier stage at zroughly-equal4 in which they are the thermal X-ray sources responsible for most of the comic X-ray background (CXB). We pursue the conjecture that these precursor objects are initially supermassive Schwarzschild black holes with accretion disks radiating near the Eddington luminosity limit. It is noted that after approx.10 8 years these central black holes are spun up to a ''canonical'' Kerr equilibriuim state (a/M = 0.998) and shown how they can lead to spectral evolution involving nonthermal emission extending to gamma-rays, at the expense of reduced thermal disk radiation. A superposition of sources in the precursor stage can thereby account for that major portion of the CXB remaining after the contributions of usual AGN are considered, while a superposition of AGN sources at z<1 can account for the gamima-ray background. Extensive X-ray measurements carried out with the HEAO 1 and HEAO 2 missions, as well as gamma-ray and optical data, are shown to compare favorably with principal features of this model. Several further observational tests are suggested for establishing the validity of this scenario for AGN spectral evolution

Laboratory tests on neutron shields for gamma-ray detectors in space

CERN Document Server

Hong, J; Hailey, C J

2000-01-01

Shields capable of suppressing neutron-induced background in new classes of gamma-ray detectors such as CdZnTe are becoming important for a variety of reasons. These include a high cross section for neutron interactions in new classes of detector materials as well as the inefficient vetoing of neutron-induced background in conventional active shields. We have previously demonstrated through Monte-Carlo simulations how our new approach, supershields, is superior to the monolithic, bi-atomic neutron shields which have been developed in the past. We report here on the first prototype models for supershields based on boron and hydrogen. We verify the performance of these supershields through laboratory experiments. These experimental results, as well as measurements of conventional monolithic neutron shields, are shown to be consistent with Monte-Carlo simulations. We discuss the implications of this experiment for designs of supershields in general and their application to future hard X-ray/gamma-ray experiments...

Neutron-induced gamma-ray spectroscopy: simulations for chemical mapping of planetary surfaces

International Nuclear Information System (INIS)

Brueckner, J.; Waenke, H.; Reedy, R.C.

1986-01-01

Cosmic rays interact with the surface of a planetary body and produce a cascade of secondary particles, such as neutrons. Neutron-induced scattering and capture reactions play an important role in the production of discrete gamma-ray lines that can be measured by a gamma-ray spectrometer on board of an orbiting spacecraft. These data can be used to determine the concentration of many elements in the surface of a planetary body, which provides clues to its bulk composition and in turn to its origin and evolution. To investigate the gamma rays made by neutron interactions, thin targets were irradiated with neutrons having energies from 14 MeV to 0.025 eV. By means of foil activation technique the ratio of epithermal to thermal neutrons was determined to be similar to that in the Moon. Gamma rays emitted by the targets and the surrounding material were detected by a high-resolution germanium detector in the energy range of 0.1 to 8 MeV. Most of the gamma-ray lines that are expected to be used for planetary gamma-ray spectroscopy were found in the recorded spectra and the principal lines in these spectra are presented. 58 refs., 7 figs., 9 tabs

Measurement of prompt fission gamma-ray spectra in fast neutron-induced fission

International Nuclear Information System (INIS)

Laborie, J.M.; Belier, G.; Taieb, J.

2012-01-01

Knowledge of prompt fission gamma-ray emission has been of major interest in reactor physics for a few years. Since very few experimental spectra were ever published until now, new measurements would be also valuable to improve our understanding of the fission process. An experimental method is currently being developed to measure the prompt fission gamma-ray spectrum from some tens keV up to 10 MeV at least. The mean multiplicity and total energy could be deduced. In this method, the gamma-rays are measured with a bismuth germanate (BGO) detector which has the advantage to present a high P/T ratio and a high efficiency compared to other gamma-ray detectors. The prompt fission neutrons are rejected by the time of flight technique between the BGO detector and a fission trigger given by a fission chamber or a scintillating active target. Energy and efficiency calibration of the BGO detector were carried out up to 10.76 MeV by means of the Al-27(p, gamma) reaction. First prompt fission gamma-ray spectrum measurements performed for the spontaneous fission of Cf-252 and for 1.7 and 15.6 MeV neutron-induced fission of U-238 at the CEA, DAM, DIF Van de Graaff accelerator, will be presented. (authors)

The induced radioactivity danger parameter for gamma radiation

International Nuclear Information System (INIS)

Perry, D.R.

1985-07-01

Dosimetric and practical aspects of the induced radioactivity danger parameter, as used for calculating the gamma radiation dose rate near to objects that have been exposed to high energy radiation, are examined. A simplified and more generally applicable method of calculation is proposed, based on energy balance in homogeneous media. The problems of applying this in practice are discussed, and it is shown that corrections are generally small enough to be neglected in many practical applications. Examples of calculations by previous and proposed methods are given. (author)

Rain-Induced Increase in Background Radiation Detected by Radiation Portal Monitors

Energy Technology Data Exchange (ETDEWEB)

Hausladen, Paul [ORNL; Blessinger, Christopher S [ORNL; Guzzardo, Tyler [ORNL; Livesay, Jake [ORNL

2012-07-01

A complete understanding of both the steady state and transient background measured by Radiation Portal Monitors (RPMs) is essential to predictable system performance, as well as maximization of detection sensitivity. To facilitate this understanding, a test bed for the study of natural background in RPMs has been established at the Oak Ridge National Laboratory. This work was performed in support of the Second Line of Defense Program's mission to detect the illicit movement of nuclear material. In the present work, transient increases in gamma ray counting rates in RPMs due to rain are investigated. The increase in background activity associated with rain, which has been well documented in the field of environmental radioactivity, originates from the atmospheric deposition of two radioactive daughters of radon-222, namely lead-214 and bismuth-214 (henceforth {sup 222}Rn, {sup 214}Pb and {sup 214}Bi). In this study, rainfall rates recorded by a co-located weather station are compared with RPM count rates and High Purity Germanium spectra. The data verifies these radionuclides are responsible for the dominant transient natural background fluctuations in RPMs. Effects on system performance and potential mitigation strategies are discussed.

Wheat and triticale breeding using gamma-ray-induced variability

International Nuclear Information System (INIS)

Parodi, P.C.; Nebreda, I.M.

1984-01-01

Use of gamma-ray-induced variability in wheat has proved to be a valuable breeding methodology. Results with triticale are still inconclusive. After several years of research a number of wheat mutants have been developed which possess an improved protein content, high yield, good agronomic type and wide adaptability. A change in the stem rust (Puccinia graminis f. sp. tritici) population, however, rendered most of the mutants susceptible to this disease. One mutant, recently named Carolina, which was able to withstand the effects of stem rust without serious yield deterioration, was registered and released to farmers. Efforts are being made to add stem rust resistance to the susceptible mutants by conventional backcrossing. Also, new material and the most outstanding susceptible mutants were gamma irradiated in an effort to induce resistance. Other mutants, not necessarily with an improved protein content, were grouped according to disease reaction and phenotypic similarity to form multilineal composites, some of which have had a superior performance and may be released to farmers in late 1984. A study conducted under four nitrogen levels with six wheat protein mutants showed a weak and inconsistent negative correlation between yield and protein content. The mutants could be differentiated by their increased protein content under most nitrogen rates. (author)

Machine Induced Experimental Background Conditions in the LHC

CERN Document Server

Levinsen, Yngve Inntjore; Stapnes, Steinar

2012-09-19

The Large Hadron Collider set a new energy record for particle accelerators in late 2009, breaking the previous record held by Tevatron of 2 TeV collision energy. The LHC today operates at a collision energy of 7 TeV. With higher beam energy and intensity, measures have to be taken to ensure optimal experimental conditions and safety of the machine and detectors. Machine induced experimental background can severely reduce the quality of experimental triggers and track reconstruction. In a worst case, the radiation levels can be damaging for some of the subdetectors. The LHC is a particular challenge in this regard due to the vastly different operating conditions of the different experiments. The nominal luminosity varies by four orders of magnitude. The unprecedented stored beam energy and the amount of superconducting elements can make it challenging to protect the accelerator itself as well. In this work we have simulated and measured the machine induced background originating from various sources: the beam...

The combined effect of uranium and gamma radiation on biological responses and oxidative stress induced in Arabidopsis thaliana

International Nuclear Information System (INIS)

Vanhoudt, Nathalie; Vandenhove, Hildegarde; Horemans, Nele; Wannijn, Jean; Van Hees, May; Vangronsveld, Jaco; Cuypers, Ann

2010-01-01

Uranium never occurs as a single pollutant in the environment, but always in combination with other stressors such as ionizing radiation. As effects induced by multiple contaminants can differ markedly from the effects induced by the individual stressors, this multiple pollution context should not be neglected. In this study, effects on growth, nutrient uptake and oxidative stress induced by the single stressors uranium and gamma radiation are compared with the effects induced by the combination of both stressors. By doing this, we aim to better understand the effects induced by the combined stressors but also to get more insight in stressor-specific response mechanisms. Eighteen-day-old Arabidopsis thaliana seedlings were exposed for 3 days to 10 μM uranium and 3.5 Gy gamma radiation. Gamma radiation interfered with uranium uptake, resulting in decreased uranium concentrations in the roots, but with higher transport to the leaves. This resulted in a better root growth but increased leaf lipid peroxidation. For the other endpoints studied, effects under combined exposure were mostly determined by uranium presence and only limited influenced by gamma presence. Furthermore, an important role is suggested for CAT1/2/3 gene expression under uranium and mixed stressor conditions in the leaves.

Incidence and nature of tumors induced in Sprague-Dawley rats by gamma-irradiation

International Nuclear Information System (INIS)

Gross, L.; Dreyfuss, Y.; Faraggiana, T.

1988-01-01

In our previous studies carried out on inbred rats of the Sprague-Dawley strain, the tumor incidence was increased following irradiation (150 rads, 5 times, at weekly intervals), from 22 to 93% in females and from 5 to 59% in males. Experiments here reported suggest that 2 consecutive total-body gamma-irradiations of 150 rads each are sufficient to induce in rats the development of tumors, some malignant; 18 of 19 females (94.7%) developed tumors at an average age of 11.4 mo, and seven of the 14 males in this group (50%) developed tumors at an average age of 10.4 mo. In the second group, which received 3 consecutive gamma-irradiations, 20 of 23 females (86.9%) and 5 of 13 males (38.4%) developed tumors at average ages of 9.1 and 7.5 mo, respectively. In the third group, among rats which received 4 consecutive gamma-irradiations, 17 of 19 females (89.4%) and 4 of 12 males (33.3%) developed tumors at average ages of 9.4 and 10.5 mo, respectively. The etiology of tumors either developing spontaneously or induced by irradiation in rats remains to be clarified. Our attempts to detect virus particles by electron microscopy in such tumors or lymphomas have not been successful. As a working hypothesis, we are tempted to theorize that tumors or lymphomas developing spontaneously or induced by gamma irradiation in rats are caused by latent viral agents which are integrated into the cell genome and are cell associated, i.e., not separable from the rat tumor cells by conventional methods thus far used

Measurement of secondary gamma-ray production cross sections of structural materials for fusion reactor. Extraction of discrete and continuum components

International Nuclear Information System (INIS)

Kondo, Tetsuo; Morotomi, Ryutaro; Nishio, Takashi; Murata, Isao; Takahashi, Akito

2000-01-01

A new method to deal with measured spectrum of secondary gamma-rays induced by D-T neutrons with Ge detector is proposed. Subtracting background components and discrete peaks from the raw secondary gamma-ray spectrum, the continuum component of secondary gamma-ray was successfully extracted. By using unfolding process, the continuum component of the secondary gamma-ray production cross section was derived. The measured cross section data obtained by this method are very useful for precise evaluation of secondary gamma-ray production cross sections. (author)

Measurements of proton induced gamma-ray emission cross sections and yields on Al and Na

International Nuclear Information System (INIS)

Chiari, M.

2014-01-01

Full text: The measurement of the proton induced gamma-ray emission cross sections on low-Z nuclei such as Na and Al of specific interest for environmental and cultural heritage applications, were carried out for proton beam energy from 2.5 to 4.1 MeV, including the measurement of the angular distributions of the emitted rays at selected angles, i.e. 90°, 45° and 0°, using an array of three HPGe detectors coupled to the multi-purpose scattering chamber on the +30° beamline of the Tandetron accelerator at INFN LABEC. The studied gamma-ray inducing reactions were: "2"7Al(p,p’γ)"2"7Al (gamma-ray energies 844 and 1014 keV), and "2"3Na(p,p"’γ)"2"3Na (gamma-ray energies 441 and 1636 keV) and "2"3Na(p,"αγ)"2"0Ne (gamma-ray energy 1634 keV). As a first step, the absolute efficiency of the HPGe detectors placed at 90° and 0° was improved by a factor up to 2 by designing a new target holder, with less absorbing material facing the HPGe detector at 90°, and installing a new Faraday cup/beam stopper with graphite body instead of stainless steel and a thinner Ta cap at the bottom, to reduce the shielding effect for the HPGe detector at 0°. The measurement of the absolute efficiency of the HPGe detectors of the array was carried out using a "1"5"2Eu calibration source mounted on the target holder and placed in the exact position of the target under irradiation. The proton beam energy was calibrated using an aluminum thick target and the resonances at 991.86 keV and 1683.57 keV, respectively in the (p,γ) and (p,p"’γ) reactions on "2"7Al, and a native aluminium oxide thin target and the resonance at 3470 keV in elastic scattering on "1"6O. The targets employed were thin Al (29 μg/cm"2) and NaF (35 μg/cm"2) films evaporated on thin self-supporting Ag foils; in order to obtain the differential gamma-ray inducing cross-sections, we normalized the results by the Rutherford elastic backscattering of protons from Ag, adopting a procedure not relying on the

Role of activatory Fc gamma RI and Fc gamma RIII and inhibitory Fc gamma RII in inflammation and cartilage destruction during experimental antigen-induced arthritis.

NARCIS (Netherlands)

Lent, P.L.E.M. van; Nabbe, K.C.A.M.; Blom, A.B.; Holthuysen, A.E.M.; Sloetjes, A.W.; Putte, L.B.A. van de; Verbeek, S.; Berg, W.B. van den

2001-01-01

IgG-containing immune complexes, which are found in most RA joints, communicate with hematopoietic cells using three classes of Fc receptors(Fc gamma RI, -II, -III). In a previous study we found that if a chronic T-cell-mediated antigen-induced arthritis (AIA) was elicited in knee joints of FcR

Impact of detector efficiency and energy resolution on gamma-ray background rejection in mobile spectroscopy and imaging systems

Energy Technology Data Exchange (ETDEWEB)

Aucott, Timothy J., E-mail: Timothy.Aucott@SRS.gov [Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Bandstra, Mark S. [Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Negut, Victor; Curtis, Joseph C. [University of California, Berkeley, Department of Nuclear Engineering, Berkeley, CA (United States); Meyer, Ross E.; Chivers, Daniel H. [Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Vetter, Kai [University of California, Berkeley, Department of Nuclear Engineering, Berkeley, CA (United States); Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States)

2015-07-21

The presence of gamma-ray background significantly reduces detection sensitivity when searching for radioactive sources in the field, and the systematic variability in the background will limit the size and energy resolution of systems that can be used effectively. An extensive survey of the background was performed using both sodium iodide and high-purity germanium. By using a bivariate negative binomial model for the measured counts, these measurements can be resampled to simulate the performance of a detector array of arbitrary size and resolution. The response of the system as it moved past a stationary source was modeled for spectroscopic and coded aperture imaging algorithms and used for source injection into the background. The performance of both techniques is shown for various sizes and resolutions, as well as the relative performance for sodium iodide and germanium. It was found that at smaller detector sizes or better energy resolution, spectroscopy has higher detection sensitivity than imaging, while imaging is better suited to larger or poorer resolution detectors.

The Monte Carlo simulation of the neutron-induced prompt gamma ray spectroscopy of the CW abandoned by Japan

International Nuclear Information System (INIS)

Wang Bairong; Yang Zhongping; Zhan Wenzhong

2003-01-01

This paper introduced the principle of identifying the chemical weapon abandoned by Japan by neutron-induced prompt gamma ray. Using the MCNP-4C Monte Carlo program, this paper simulated and analyzed the neutron-induced prompt gamma ray spectroscopy of chemical weapon abandoned by Japan, whereby supply important datum and reference for the aftertime deeper research and disposal of Japan-abandoned chemical weapon. (authors)

Gamma-ray induced delay of fruiting body initiation in a basidiomycete, Hebeloma vinosophyllum

International Nuclear Information System (INIS)

Takimoto, K.

1980-01-01

The effect of gamma-radiation on fruiting body initiation in a basidiomycete, Hebeloma vinosophyllum, was investigated. Fruiting of this fungus is induced by visible light, but irradiation of the mycelium before or after light treatment delayed fruiting body initiation. The time required for fruiting body initiation increased with the radiation dose. The induction of fruiting bodies had two gamma-radiation sensitive stages, one immediately before fruiting body initiation and the other 15 to 20 h after the start of photoinduction. (author)

Inhibition of gamma-radiation induced DNA damage in plasmid pBR322 by TMG, a water-soluble derivative of vitamin E.

Science.gov (United States)

Rajagopalan, Rema; Wani, Khalida; Huilgol, Nagaraj G; Kagiya, Tsutomu V; Nair, Cherupally K Krishnan

2002-06-01

Alpha-tocopherol monoglucoside (TMG), a water-soluble derivative of alpha-tocopherol, has been examined for its ability to protect DNA against radiation-induced strand breaks. Gamma radiation, up to a dose of 6 Gy (dose rate, 0.7 Gy/minute), induced a dose-dependent increase in single strand breaks (SSBs) in plasmid pBR322 DNA. TMG inhibited the formation of gamma-radiation induced DNA single strand breaks (SSBs) in a concentration-dependent manner; 500 microM of TMG protected the single strand breaks completely. It also protected thymine glycol formation induced by gamma-radiation in a dose-dependent manner, based on an estimation of thymine glycol by HPLC.

Inhibition of {gamma}-radiation induced DNA damage in plasmid pBR322 by TMG, a water-soluble derivative of vitamin E

Energy Technology Data Exchange (ETDEWEB)

Rajagopalan, R.; Nair, C.K.K. [Bhabha Atomic Research Centre, Mumbai (India); Wani, K.; Huilgol, N.G. [Nanavati Hospital and MRC, Vile Parle (India); Kagiya, Tsutomu V. [Kinki Research Foundation, Kyoto (Japan)

2002-06-01

Alpha-tocopherol monoglucoside (TMG), a water-soluble derivative of {alpha}-tocopherol, has been examined for its ability to protect DNA against radiation-induced strand breaks. Gamma radiation, up to a dose of 6 Gy (dose rate, 0.7 Gy/minute), induced a dose-dependent increase in single strand breaks (SSBs) in plasmid pBR322 DNA. TMG inhibited the formation of {gamma}-radiation induced DNA single strand breaks (SSBs) in a concentration-dependent manner; 500 {mu}M of TMG protected the single strand breaks completely. It also protected thymine glycol formation induced by {gamma}-radiation in a dose-dependent manner, based on an estimation of thymine glycol by HPLC. (author)

Analysis of unstable chromosome alterations frequency induced by neutron-gamma mixed field radiation

Energy Technology Data Exchange (ETDEWEB)

Souza, Priscilla L.G.; Brandao, Jose Odinilson de C.; Vale, Carlos H.F.P.; Santos, Joelan A.L.; Vilela, Eudice C.; Lima, Fabiana F. [Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil)], e-mail: psouza@cnen.gov.br, e-mail: jodinilson@cnen.gov.br; Calixto, Merilane S.; Santos, Neide [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Genetica

2009-07-01

Nowadays monitoring chromosome alterations in peripheral blood lymphocytes have been used to access the radiation absorbed dose in individuals exposed accidental or occupationally to gamma radiation. However there are not many studies based on the effects of mixed field neutron-gamma. The radiobiology of neutrons has great importance because in nuclear factories worldwide there are several hundred thousand individuals monitored as potentially receiving doses of neutron. In this paper it was observed the frequencies of unstable chromosome alterations induced by a gamma-neutron mixed field. Blood was obtained from one healthy donor and exposed to mixed field neutron-gamma sources {sup 241}AmBe (20 Ci) at the Neutron Calibration Laboratory (NCL-CRCN/NE-PE-Brazil). The chromosomes were observed at metaphase, following colcemid accumulation and 1000 well-spread metaphases were analyzed for the presence of chromosome alterations by two experienced scorers. The results suggest that there is the possibility of a directly proportional relationship between absorbed dose of neutron-gamma mixed field radiation and the frequency of unstable chromosome alterations analyzed in this paper. (author)

Analysis of unstable chromosome alterations frequency induced by neutron-gamma mixed field radiation

International Nuclear Information System (INIS)

Souza, Priscilla L.G.; Brandao, Jose Odinilson de C.; Vale, Carlos H.F.P.; Santos, Joelan A.L.; Vilela, Eudice C.; Lima, Fabiana F.; Calixto, Merilane S.; Santos, Neide

2009-01-01

Nowadays monitoring chromosome alterations in peripheral blood lymphocytes have been used to access the radiation absorbed dose in individuals exposed accidental or occupationally to gamma radiation. However there are not many studies based on the effects of mixed field neutron-gamma. The radiobiology of neutrons has great importance because in nuclear factories worldwide there are several hundred thousand individuals monitored as potentially receiving doses of neutron. In this paper it was observed the frequencies of unstable chromosome alterations induced by a gamma-neutron mixed field. Blood was obtained from one healthy donor and exposed to mixed field neutron-gamma sources 241 AmBe (20 Ci) at the Neutron Calibration Laboratory (NCL-CRCN/NE-PE-Brazil). The chromosomes were observed at metaphase, following colcemid accumulation and 1000 well-spread metaphases were analyzed for the presence of chromosome alterations by two experienced scorers. The results suggest that there is the possibility of a directly proportional relationship between absorbed dose of neutron-gamma mixed field radiation and the frequency of unstable chromosome alterations analyzed in this paper. (author)

Influence of genic status in relation to gamma ray and EMS induced pollen sterility in chillies (Capsicum Annum L.)

International Nuclear Information System (INIS)

Asha, M.S.; Nayar, N.K.

1986-01-01

Fifteen genotypes of the same species tested to study the effect of gamma rays and ethylmethane sulphonate showed wide variability in their effect. Pollen sterility increased with increase in dose. Gamma rays induced a higher per cent sterility compared to EMS. Genic status influenced variation was noted in the effect of mutagens in inducing pollen sterility. 7 refs. (author)

Glutamate decarboxylase and. gamma. -aminobutyric acid transaminase activity in brain structures during action of high concentrated sulfide gas on a background of hypo- and hypercalcemia

Energy Technology Data Exchange (ETDEWEB)

Kadyrov, G.K.; Aliyev, A.M.

Activity of the following enzymes was studied on the background of hypo- and hypercalcemia and exposure to high concentration of sulfide gas: glutamate decarboxylase (GDC) and {gamma}-aminobutyric acid transaminase (GABA-T). These enzymes regulate metabolism of GABA. The results showed that a 3.5 hr exposure to sulfide gas at a concentration of 0.3 mg/1 led to significantly increased activity of GDC in cerebral hemispheres, cerebellum and in brain stem. Activity of GABA-T dropped correspondingly. On the background of hypercalcemia induced by im. injection of 10% calcium gluconate (0.6 m1/200 g body weight of experimental rats) the negative effect caused by the exposure to sulfide gas was diminished. Under conditions of hypocalcemia (im. injection of 10 mg/200 g body weight of sodium oxalate), exposure to sulfide gas led to a significantly decreased activity of GDC and GABA-T in the hemispheres and in the brain stem, but in the cerebellum the activity of GDC increased sharply while that of GABA-T decreased correspondingly. 8 refs.

Gamma radiation induced changes in nuclear waste glass containing Eu

Science.gov (United States)

Mohapatra, M.; Kadam, R. M.; Mishra, R. K.; Kaushik, C. P.; Tomar, B. S.; Godbole, S. V.

2011-10-01

Gamma radiation induced changes were investigated in sodium-barium borosilicate glasses containing Eu. The glass composition was similar to that of nuclear waste glasses used for vitrifying Trombay research reactor nuclear waste at Bhabha Atomic Research Centre, India. Photoluminescence (PL) and electron paramagnetic resonance (EPR) techniques were used to study the speciation of the rare earth (RE) ion in the matrix before and after gamma irradiation. Judd-Ofelt ( J- O) analyses of the emission spectra were done before and after irradiation. The spin counting technique was employed to quantify the number of defect centres formed in the glass at the highest gamma dose studied. PL data suggested the stabilisation of the trivalent RE ion in the borosilicate glass matrix both before and after irradiation. It was also observed that, the RE ion distributes itself in two different environments in the irradiated glass. From the EPR data it was observed that, boron oxygen hole centre based radicals are the predominant defect centres produced in the glass after irradiation along with small amount of E’ centres. From the spin counting studies the concentration of defect centres in the glass was calculated to be 350 ppm at 900 kGy. This indicated the fact that bulk of the glass remained unaffected after gamma irradiation up to 900 kGy.

{gamma}-irradiation-induced oxidative stress and aging of cultured endothelial cells; Stress oxydant et vieillissement vasculaire in vitro etude apres irradiation {gamma} de cellules endotheliales

Energy Technology Data Exchange (ETDEWEB)

Van Uye, A.; Agay, D.; Drouet, M.; Chancerelle, Y.; Mathieu, J.; Kergonou, J.F.; Mestries, J.C.

1995-12-31

The aim of this work was to study aging of cultured vascular cells. In order to induce an oxidative stress, which is known to participate in aging process, we apply {gamma}-induced peroxidation and is revealed by indirect immunofluorescence. (author). 6 refs.

The progress of neutron induced prompt gamma analysis technique in 1988-2002

International Nuclear Information System (INIS)

Liu Yuren; Jing Shiwei

2003-01-01

The new development of the neutron induced prompt gamma-ray analysis (NIPGA) technology in 1988-2002 are described. The pulse fast-thermal neutron activation analysis method, which utilizes the inelastic reaction and capture reaction jointly is employed to measure the elemental content in the material more efficiently. The lifetime of the neutron generator is more than 10000 h and the capability of HPGe, TeZeCd and MCA (multi-channel analyser) reaches the high level. At the same time, Monte Carlo Library least-square method is used to solve the nonlinearity problem in the PGNAA (Prompt Gamma Neutron Activation Analysis)

Interferon-gamma sensitizes colonic epithelial cell lines to physiological and therapeutic inducers of colonocyte apoptosis.

LENUS (Irish Health Repository)

O'Connell, J

2012-02-03

Homeostasis in the colonic epithelium is achieved by a continuous cycle of proliferation and apoptosis, in which imbalances are associated with disease. Inflammatory bowel disease (IBD) and colon cancer are associated with either excessive or insufficient apoptosis of colonic epithelial cells, respectively. By using two colonic epithelial cell lines, HT29 and SW620, we investigated how the epithelial cell\\'s sensitivity to apoptosis was regulated by the proinflammatory cytokine interferon-gamma (IFN-gamma). We found that IFN-gamma sensitized HT29 cells, and to a lesser extent SW620, to diverse inducers of apoptosis of physiologic or therapeutic relevance to the colon. These apoptosis inducers included Fas (CD95\\/APO-1) ligand (FasL), short-chain fatty acids, and chemotherapeutic drugs. The extent of IFN-gamma-mediated apoptosis sensitization in these two cell lines correlated well with the degree of IFN-gamma-mediated upregulation of the proapoptotic protease caspase-1. Although IFN-gamma alone effectively sensitized HT29 cells to apoptosis, inclusion of the protein synthesis inhibitor cyclohexamide (CHX) during apoptotic challenge was necessary for maximal sensitization of SW620. The requirement of CHX to sensitize SW620 cells to apoptosis implies a need to inhibit translation of antiapoptotic proteins absent from HT29. In particular, the antiapoptotic protein Bcl-2 was strongly expressed in SW620 cells but absent from HT29. Our results indicate that IFN-gamma increases the sensitivity of colonic epithelial cells to diverse apoptotic stimuli in concert, via upregulation of caspase-1. Our findings implicate caspase-1 and Bcl-2 as important central points of control determining the general sensitivity of colonic epithelial cells to apoptosis.

Protective role of garlic against gamma radiation induced histological and histochemical changes in rat liver

International Nuclear Information System (INIS)

Abdel Motaal, N.A.; Abdel Maguid, A.

2007-01-01

The present work was planned to evaluate the radioprotective effect of garlic (Allium sativum) against the hazardous action of gamma radiation on liver of rat one and ten days post-exposure. Garlic was orally administered (100 mg/ kg body wt) to rats daily for two weeks before exposure to single dose whole body gamma-irradiation (5Gy). The results showed that exposure of rats to gamma- irradiation caused massive portal infiltration with inflammatory cells, dilatation of blood sinusoids, an increase in the number of Kupffer cells, vacuolation of some hepatocytes as well as pyknosis and karyolysis of hepatic nuclei in the liver tissue. Histochemical examination of liver one day post- irradiation illustrated weak to moderate glycogen particles. While, on ten days post-irradiation, a strong activity for glycogen was detected. The disturbance in carbohydrate metabolism is closely related to the radiation induced histological damage in the liver tissue. Administration of garlic for 2 weeks pre-irradiation reduced the radiation induced histopathological changes and showed marked protection against the tissue damaging effect of radiation. It could be concluded that treatment of rats with garlic before exposure to gamma-irradiation offered a noticeable radioprotective effect of the studied organ

Neutron induced gamma spectrometry for on-line compositional analysis in coal conversion and fluidized-bed combustion plants

International Nuclear Information System (INIS)

Herzenberg, C.L.; O'Fallon, N.M.; Yarlagadda, B.S.; Doering, R.W.; Cohn, C.E.; Porges, K.G.; Duffey, D.

1977-01-01

Nuclear techniques involving relatively penetrating radiation may offer the possibility of non-invasive, continuous on-line instrumental monitoring which is representative of the full process stream. Prompt gamma rays following neutron capture are particularly attractive because the penetrating power of the neutrons and the, typically several MeV, capture gammas makes possible interrogation of material within a pipe. We are evaluating neutron capture gamma techniques for this application, both for elemental composition monitoring and for mass-flow measurement purposes, and this paper will present some recent work on composition analysis by neutron induced gamma spectrometry

Superantigen and HLA-DR ligation induce phospholipase-C gamma 1 activation in class II+ T cells

DEFF Research Database (Denmark)

Kanner, S B; Odum, Niels; Grosmaire, L

1992-01-01

Bacterial enterotoxin superantigens bind directly to HLA class II molecules (HLA-DR) expressed on both APC and activated human T cells, and simultaneously bind to certain V beta chains of the TCR. In this report, we compared early T cell signaling events in human alloantigen-stimulated T cells when...... activated by HLA-DR ligation through antibody cross-linking or by direct enterotoxin superantigen binding. Both types of stimuli induced tyrosine phosphorylation of phosphatidylinositol-specific phospholipase C gamma 1 (PLC gamma 1) and an increase in intracellular calcium concentration; however......, superantigen-induced signaling was stronger than class II ligation alone. Antibody-mediated ligation of HLA-DR with CD3 resulted in augmented PLC gamma 1 activation and increased calcium mobilization, consistent with a mechanism of superantigen activity through a combination of class II and CD3/Ti signals...

Nature of mutants induced by ionizing radiation in cultured hamster cells. II. Antigenic response and reverse mutation of HPRT-deficient mutants induced by. gamma. -rays or ethyl methanesulphonate

Energy Technology Data Exchange (ETDEWEB)

Brown, R; Stretch, A; Thacker, J

1986-04-01

A large series of independent mutants deficient in HPRT enzyme activity, isolated from V79-4 hamster cells, were assessed for properties which reflect the nature of the genetic changes induced. A total of 88 mutants were screened, 43 isolated from ..gamma..-ray-treated cultures and 45 induced by ethyl methanesulphonate (EMS). Firstly, each mutant was assayed for the presence of protein with the antigenic response of HPRT. In a competitive inhibition assay, 31% of EMS-induced mutants were CRM-positive compared to 7% of the ..gamma..-ray series. Secondly, each mutant was tested for ability to revert to HPRT proficiency. All except 2 of the EMS-induced mutants reverted with ethyl nitrosourea ENU, and many reverted spontaneously, under the given conditions. However reversion was not detected in about 80% of ..gamma..-ray-induced mutants, suggesting that the types of forward mutation caused by ionizing radiation differ qualitatively from those caused by EMS. (Auth.). 30 refs.; 6 figs.; 2 tabs.

Neutron and gamma-ray emission in the proton induced fission of {sup 238}U and {sup 242}Pu

Energy Technology Data Exchange (ETDEWEB)

Kniajeva, G.N.; Krupa, L.; Bogachev, A.A.; Chubarian, G.G.; Dorvaux, O.; Itkis, I.M.; Itkis, M.G.; Kliman, J.; Khlebnikov, S.; Kondratiev, N.A.; Kozulin, E.M.; Lyapin, V.; Materna, T.; Pokrovsky, I.V.; Rubchenya, V.A.; Trzaska, W.H.; Vakhtin, D.; Voskressenski, V.M

2004-04-05

Average prescission M{sup pre}{sub n} and postscission M{sup post}{sub n} neutron multiplicities as well as average {gamma}-ray multiplicity gamma}}>, average energy gamma}}> emitted by {gamma}-rays as a function of mass and total kinetic energy (TKE) of fission fragments were measured in proton induced reactions p+{sup 242}Pu{yields}{sup 243}Am, p+{sup 238}U{yields}{sup 239}Np at proton energy E{sub p}=13, 20 and 55 MeV.

Spectral analysis of paramagnetic centers induced in human tooth enamel by x-rays and gamma radiation

Science.gov (United States)

Kirillov, V. A.; Kuchuro, I. I.

2010-03-01

Based on study of spectral and relaxation characteristics, we have established that paramagnetic centers induced in tooth enamel by x-rays and gamma radiation are identical in nature. We show that for the same exposure dose, the intensity of the electron paramagnetic resonance (EPR) signal induced by x-radiation with effective energy 34 keV is about an order of magnitude higher than the amplitude of the signal induced by gamma radiation. We have identified a three-fold attenuation of the EPR signal along the path of the x-radiation from the buccal to the lingual side of a tooth, which is evidence that the individual had undergone diagnostic x-ray examination of the dentition or skull. We have shown that the x-ray exposure doses reconstructed from the EPR spectra are an order of magnitude higher than the applied doses, while the dose loads due to gamma radiation are equal to the applied doses. The data obtained indicate that for adequate reconstruction of individual absorbed doses from EPR spectra of tooth enamel in the population subjected to the combined effect of x-radiation and accidental external gamma radiation as a result of the disaster at the Chernobyl nuclear power plant, we need to take into account the contribution to the dose load from diagnostic x-rays in examination of the teeth, jaw, or skull.

Anisotropies in the diffuse gamma-ray background from dark matter with Fermi LAT: a closer look

DEFF Research Database (Denmark)

Cuoco, Alessandro; Sellerholm, A.; Conrad, J.

2011-01-01

We perform a detailed study of the sensitivity to the anisotropies related to dark matter (DM) annihilation in the isotropic gamma-ray background (IGRB) as measured by the Fermi Large Area Telescope (Fermi LAT). For the first time, we take into account the effects of the Galactic foregrounds...... of the detector are taken into account by convolving the model maps with the Fermi LAT instrumental response. We then use the angular power spectrum to characterize the anisotropy properties of the simulated data and to study the sensitivity to DM. We consider DM anisotropies of extragalactic origin...

Summary report of the first research coordination meeting on development of a reference database for particle-induced gamma ray emission (PIGE) spectroscopy

International Nuclear Information System (INIS)

Abriola, D.; Pedro de Jesus, A.

2011-07-01

The First Research Coordination Meeting (RCM) of the IAEA Coordinated Research Project (CRP) on 'Development of a Reference Database for Particle-Induced Gamma-ray Emission (PIGE) Spectroscopy' was held at the IAEA, Vienna, from 16-20 May 2011. A summary of the participants' presentations is given as well as background information, objectives and recommendations concerning approach and methodology. The extension of the IBANDL database format to include PIGE data was discussed. The different tasks to achieve the CRP objectives were assigned to participants. A list of priority measurements was produced and the individual sets of measurements assigned to participants. (author)

Implementation of neutron-induced gamma-ray spectroscopy in industrial applications

International Nuclear Information System (INIS)

Abernethy, D. A.; Lim, C. S.

2006-01-01

Full text: Neutron based analytical techniques are commonly used in a wide variety of industrial applications, with new applications continually being found. As a result, despite popular concerns about the harmful health effects of radiation the number of these analysers is increasing. This is because neutron-induced gamma-ray techniques have the capability of combining elemental sensitivity with significant penetrating power, enabling non-intrusive and non-destructive bulk elemental measurements to be averaged over a large volume of material. Neutron induced gamma ray spectroscopy has been developed by several groups, including CSIRO Minerals, for on-line measurement of elemental composition in a range of industrial applications in vessels, pipes and on conveyor belts. Compared to those typically found in a scientific laboratory, conditions in industrial plants differ substantially in a number of ways, such as environmental variability, operator skill and training, and shielding requirements. As a result of these differences, equipment and techniques which are used as a matter of course in a laboratory often have to undergo major modification to render them suitable for use in an industrial context. This paper will discuss some of the factors that have to be considered when deciding such matters with particular emphasis on the implications of radiation safety requirements

Processing of gamma-ray spectrometric logs

International Nuclear Information System (INIS)

Umiastowski, K.; Dumesnil, P.

1984-10-01

CEA (Commissariat a l'Energie Atomique) has developped a gamma-ray spectrometric tool, containing an analog-to-digital converter. This new tool permits to perform very precise uranium logs (natural gamma-ray spectrometry), neutron activation logs and litho-density logs (gamma-gamma spectrometric logs). Specific processing methods were developped to treate the particular problems of down-hole gamma-ray spectrometry. Extraction of the characteristic gamma-ray peak, even if they are superposed on the background radiation of very high intensity, is possible. This processing methode enables also to obtain geological informations contained in the continuous background of the spectrum. Computer programs are written in high level language for SIRIUS (VICTOR) and APOLLO computers. Exemples of uranium and neutron activation logs treatment are presented [fr

Developmental toxicity and oxidative stress induced by gamma irradiation in zebrafish embryos.

Science.gov (United States)

Hu, Miao; Hu, Nan; Ding, Dexin; Zhao, Weichao; Feng, Yongfu; Zhang, Hui; Li, Guangyue; Wang, Yongdong

2016-11-01

This study aimed to evaluate the biological effects of gamma irradiation on zebrafish embryos. Different doses of gamma rays (0.01, 0.05, 0.1, 0.5 and 1 Gy) were used to irradiate zebrafish embryos at three developmental stages (stage 1, 6 h post-fertilization (hpf); stage 2, 12 hpf; stage three, 24 hpf), respectively. The survival, malformation and hatching rates of the zebrafish embryos were measured at the morphological endpoint of 96 hpf. The activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx) and glutathione S-transferase (GST) were assayed. Morphology analysis showed that gamma irradiation inhibited hatching and induced developmental toxicity in a dose-dependent manner. Interestingly, after irradiation the malformation rate changed not only in a dose-dependent manner but also in a developmental stage-dependent manner, indicating that the zebrafish embryos at stage 1 were more sensitive to gamma rays than those at other stages. Biochemical analysis showed that gamma irradiation modulated the activities of antioxidant enzymes in a dose-dependent manner. A linear relationship was found between GPx activity and irradiation dose in 0.1-1 Gy group, and GPx was a suitable biomarker for gamma irradiation in the dose range from 0.1 to 1 Gy. Furthermore, the activities of SOD, CAT, GR and GPx of the zebrafish embryos at stage 3 were found to be much higher than those at other stages, indicating that the zebrafish embryos at stage 3 had a greater ability to protect against gamma rays than those at other stages, and thus the activities of antioxidant enzymes changed in a developmental stage-dependent manner.

Developmental toxicity and oxidative stress induced by gamma irradiation in zebrafish embryos

International Nuclear Information System (INIS)

Hu, Miao; Hu, Nan; Ding, Dexin; Zhao, Weichao; Feng, Yongfu; Zhang, Hui; Li, Guangyue; Wang, Yongdong

2016-01-01

This study aimed to evaluate the biological effects of gamma irradiation on zebrafish embryos. Different doses of gamma rays (0.01, 0.05, 0.1, 0.5 and 1 Gy) were used to irradiate zebrafish embryos at three developmental stages (stage 1, 6 h post-fertilization (hpf); stage 2, 12 hpf; stage three, 24 hpf), respectively. The survival, malformation and hatching rates of the zebrafish embryos were measured at the morphological endpoint of 96 hpf. The activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx) and glutathione S-transferase (GST) were assayed. Morphology analysis showed that gamma irradiation inhibited hatching and induced developmental toxicity in a dose-dependent manner. Interestingly, after irradiation the malformation rate changed not only in a dose-dependent manner but also in a developmental stage-dependent manner, indicating that the zebrafish embryos at stage 1 were more sensitive to gamma rays than those at other stages. Biochemical analysis showed that gamma irradiation modulated the activities of antioxidant enzymes in a dose-dependent manner. A linear relationship was found between GPx activity and irradiation dose in 0.1-1 Gy group, and GPx was a suitable biomarker for gamma irradiation in the dose range from 0.1 to 1 Gy. Furthermore, the activities of SOD, CAT, GR and GPx of the zebrafish embryos at stage 3 were found to be much higher than those at other stages, indicating that the zebrafish embryos at stage 3 had a greater ability to protect against gamma rays than those at other stages, and thus the activities of antioxidant enzymes changed in a developmental stage-dependent manner. (orig.)

Developmental toxicity and oxidative stress induced by gamma irradiation in zebrafish embryos

Energy Technology Data Exchange (ETDEWEB)

Hu, Miao; Hu, Nan; Ding, Dexin; Zhao, Weichao; Feng, Yongfu; Zhang, Hui; Li, Guangyue; Wang, Yongdong [University of South China, Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, Hengyang, Hunan Province (China)

2016-11-15

This study aimed to evaluate the biological effects of gamma irradiation on zebrafish embryos. Different doses of gamma rays (0.01, 0.05, 0.1, 0.5 and 1 Gy) were used to irradiate zebrafish embryos at three developmental stages (stage 1, 6 h post-fertilization (hpf); stage 2, 12 hpf; stage three, 24 hpf), respectively. The survival, malformation and hatching rates of the zebrafish embryos were measured at the morphological endpoint of 96 hpf. The activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx) and glutathione S-transferase (GST) were assayed. Morphology analysis showed that gamma irradiation inhibited hatching and induced developmental toxicity in a dose-dependent manner. Interestingly, after irradiation the malformation rate changed not only in a dose-dependent manner but also in a developmental stage-dependent manner, indicating that the zebrafish embryos at stage 1 were more sensitive to gamma rays than those at other stages. Biochemical analysis showed that gamma irradiation modulated the activities of antioxidant enzymes in a dose-dependent manner. A linear relationship was found between GPx activity and irradiation dose in 0.1-1 Gy group, and GPx was a suitable biomarker for gamma irradiation in the dose range from 0.1 to 1 Gy. Furthermore, the activities of SOD, CAT, GR and GPx of the zebrafish embryos at stage 3 were found to be much higher than those at other stages, indicating that the zebrafish embryos at stage 3 had a greater ability to protect against gamma rays than those at other stages, and thus the activities of antioxidant enzymes changed in a developmental stage-dependent manner. (orig.)

Analysis of minor elements in steel by coincidence method in deuteron-induced prompt gamma-ray emission (D-PIGE)

International Nuclear Information System (INIS)

Ene, Antoaneta; Popescu, I.; Badica, T.; Olariu, Agata; Besliu, C.

2000-01-01

Among the factors affecting the sensitivity of PIGE method (particle-induced prompt gamma-ray emission) frequently discussed in the literature, the background in the γ-ray spectrum holds a prominent place. In this work the limits of detection of minor elements in a standard steel sample (Euronorm rm No. 085/1) irradiated with 5 MeV deuterons have been determined by the regular d-PIGE method and with the selection of the (d,n) reaction channel by measuring γ--n coincidences following the reaction steel + deuterons. This approach has resulted in a significant improvement of the sensitivity of the analysis, reducing the background in prompt gamma ray spectrum by eliminating the γ--rays observed in the singular spectrum which arises from the reaction channels (d, d'), (d, γ), (d, p), (d, 3 He), (d, α) and (d, t). From the singular spectrum we could establish the presence of the elements S, Pb, Mo, Co, V, P, O, Si, Zn, Mn, Cu, Sb, C, Al, N, As, Ti and Fe. The γ--n coincidence spectrum, obtained as a result of the selection of the γ- transitions via the reaction channel (d, n), is substantially different from the singular γ--spectrum, exhibiting γ- lines of rather high intensity to be used in the analyses on a reduced background. The coincidence spectrum shows lines from S, Mo, Co, Zn, Si, Mn, V, Sb, Ti, As, Ni, Cr, P, O, Al, Cu and Fe. We also made a comparative study with the published results using 5.5 MeV protons as projectiles. While for a given energy of the protons not all the elements of interest lead to a (p, n) reaction (C, O, P, S, Si etc.), most of the (d, n) reactions are exoergic. On the other side, the identification of the elements is more difficult in the case of deuterons. (authors)

Functional state of pancreatic b-cells during drug-induced hypothyroidism and acute gamma-radiation

International Nuclear Information System (INIS)

Gatsko, G.G.; Klimenko, N.K.

2002-01-01

The combined effect of hypothyroidism caused by mecarzole incorporation and acute g-irradiation in a 1 Gy dose was studied. It was established that the gamma-irradiation on the background of hypothyroidism causes earlier, longer and more expressed activation of b-cells of the pancreas (authors)

Natural indoor gamma background in an urban environment of Southern Poland

International Nuclear Information System (INIS)

Koperski, J.

1984-01-01

A regional survey of indoor exposure to natural gamma background from terrestrial sources was performed in the urban environment of six administrative provinces of Southern Poland. 1351 dwelling houses at 144 localities were monitored using of LiF:Mg,Ti thermoluminescence dosemeters. The dose rates observed indoors were between 32 and 185 nGy.h -1 and were strongly dependent on the types of building materials used in the dwellings monitored. The highest mean provincial values were found in slag and fly-ash dwellings (77-123 nGy.h -1 ), while in wooden dwellings these values were the lowest (42-51 nGy.h -1 ). Intermediate values occurred in clay brick dwellings (57-102 nGy.h -1 ), in dwellings of mixed, wooden-brick construction (60-79 nGy,h -1 ) and in dwellings made of gravel-sand prefabricates (52-68 nGy.h -1 ). The calculated mean annual per capita effective dose equivalent rates ranged between 0.2 mSv.y -1 , for the inhabitants of wooden houses, and 0.6 mSv.y -1 for those living in houses made of coal by-product prefabricates. (author)

Matrix effects in the determination of phosphorus and sodium by proton-induced prompt gamma spectrometry

International Nuclear Information System (INIS)

Olivier, C.; Morland, H.J.

1990-01-01

By measuring the yield of prompt gamma rays, induced by accelerated charged particles, the ratio of the ranges in sample and standard can be used in the average cross-section method to determine elemental or isotopic compositions. By spiking the sample with a known amount of a compound containing a non-analyte element (absent in the sample), the appropriate range in the sample can be determined by measuring the prompt gamma rays induced in the non-analyte spike. With lithium compounds as the non-analyte spike, sodium and phosphorus were determined in ivory. The method was tested by analysing the standard reference materials SRM 91, SRM 120c, and SRM 694. 2 figs., 5 tabs., 10 refs

Cumulative Neutrino and Gamma-Ray Backgrounds from Halo and Galaxy Mergers

Science.gov (United States)

Yuan, Chengchao; Mészáros, Peter; Murase, Kohta; Jeong, Donghui

2018-04-01

The merger of dark matter halos and the gaseous structures embedded in them, such as protogalaxies, galaxies, and groups and clusters of galaxies, results in strong shocks that are capable of accelerating cosmic rays (CRs) to ≳10 PeV. These shocks will produce high-energy neutrinos and γ-rays through inelastic pp collisions. In this work, we study the contributions of these halo mergers to the diffuse neutrino flux and to the nonblazar portion of the extragalactic γ-ray background. We formulate the redshift dependence of the shock velocity, galactic radius, halo gas content, and galactic/intergalactic magnetic fields over the dark matter halo distribution up to a redshift z = 10. We find that high-redshift mergers contribute a significant amount of the CR luminosity density, and the resulting neutrino spectra could explain a large part of the observed diffuse neutrino flux above 0.1 PeV up to several PeV. We also show that our model can somewhat alleviate tensions with the extragalactic γ-ray background. First, since a larger fraction of the CR luminosity density comes from high redshifts, the accompanying γ-rays are more strongly suppressed through γγ annihilations with the cosmic microwave background and the extragalactic background light. Second, mildly radiative-cooled shocks may lead to a harder CR spectrum with spectral indices of 1.5 ≲ s ≲ 2.0. Our study suggests that halo mergers, a fraction of which may also induce starbursts in the merged galaxies, can be promising neutrino emitters without violating the existing Fermi γ-ray constraints on the nonblazar component of the extragalactic γ-ray background.

Gamma-ray induced mutation breeding in tree fruit crops

International Nuclear Information System (INIS)

Ito, Yuji

1998-01-01

In many vegetatively propagated crops and tree fruit crops, spontaneous mutations have played an important role in the development of cultivars. Thus, induced mutation breeding has been thought to be a promising way to improve commercially important cultivars. At the Institute of Radiation Breeding (IRB), studies on induced mutation breeding of temperate zone fruit trees using gamma-rays have been performed since 1962. Black spot disease, caused by Alternaria alternata Japanese pear pathotype, is one of the most serious diseases of Japanese pear (Pyrus pyrifolia NAKAI var. culta NAKAI) in Japan. It is known that some Japanese pear cultivars are completely resistant to the disease. The pathogenic fungi produces host-specific toxins (named AK-toxin) (Tanaka 1993, Otani et al. 1973). The susceptibility of Japanese pear is controlled by a single dominant gene (Kozaki 1973). To improve the Japanese pear cultivar 'Nijisseiki', which is highly susceptible to black spot disease, young grafted plants of 'Nijisseiki' have been irradiated chronically in the Gamma Field of the IRB since 1962. In 1981, one twig of a tree planted at a distance of 53 m from the 60 Co source with an exposure rate of 0.138 Gy/day (20hr-irradiation) was selected as the first resistant mutant. It was designated as cultivar 'Gold Nijisseiki' and released in 1990. A selection method for mutants resistant to black spot disease using the pathogen produced toxin and pear leaf disks was established. It is a simple and stable selection method. Up to the present, three mutant cultivars resistant to black spot disease have been bred at the IRB by chronic and acute gamma-ray irradiation. They showed intermediate resistance compared with the completely resitan cultivar 'Choujuurou' and highly susceptible cultivar 'Nijisseiki'. We obtained some apple mutants resistant to alternaria leaf blotch disease using toxin and leaf disks and are also attempting to obtain mutant resistant to some disease in other temperate

Teaching about Natural Background Radiation

Science.gov (United States)

Al-Azmi, Darwish; Karunakara, N.; Mustapha, Amidu O.

2013-01-01

Ambient gamma dose rates in air were measured at different locations (indoors and outdoors) to demonstrate the ubiquitous nature of natural background radiation in the environment and to show that levels vary from one location to another, depending on the underlying geology. The effect of a lead shield on a gamma radiation field was also…

Sensitivity of LDEF foil analyses using ultra-low background germanium vs. large NaI(Tl) multidimensional spectrometers

International Nuclear Information System (INIS)

Reeves, J.H.; Arthur, R.J.; Brodzinski, R.L.

1992-06-01

Cobalt foils and stainless steel samples were analyzed for induced 6O Co activity with both an ultra-low background germanium gamma-ray spectrometer and with a large NaI(Tl) multidimensional spectrometer, both of which use electronic anticoincidence shielding to reduce background counts resulting from cosmic rays. Aluminum samples were analyzed for 22 Na. The results, in addition to the relative sensitivities and precisions afforded by the two methods, are presented

Characterization of gaseous detectors at the CERN Gamma Irradiation Facility: GEM performance in presence of high background radiation

CERN Document Server

AUTHOR|(CDS)2097588

Muon detection is an efficient tool to recognize interesting physics events over the high background rate expected at the Large Hadron Collider (LHC) at CERN. The muon systems of the LHC experiments are based on gaseous ionization detectors. In view of the High-Luminosity LHC (HL-LHC) upgrade program, the increasing of background radiation could affect the gaseous detector performance, especially decreasing the efficiency and shortening the lifetime through ageing processes. The effects of charge multiplication, materials and gas composition on the ageing of gaseous detectors have been studied for decades, but the future upgrade of LHC requires additional studies on this topic. At the CERN Gamma Irradiation Facility (GIF++), a radioactive source of cesium-137 with an activity of 14 TBq is used to reproduce reasonably well the expected background radiation at HL-LHC. A muon beam has been made available to study detector performance. The characterization of the beam trigger will be discussed in the present w...

Presence of neutrons in the low-level background environment estimated by the analysis of the 595.8 keV gamma peak

Energy Technology Data Exchange (ETDEWEB)

Anđelić, Brankica; Knežević, David; Jovančević, Nikola; Krmar, Miodrag; Petrović, Jovana; Toth, Arpad; Medić, Žarko; Hansman, Jan

2017-04-21

In order to explore possible improvements of the existing techniques developed to estimate the neutron fluence in low-background Ge-spectroscopy systems, gamma spectra were collected by a HPGe detector in the presence of the {sup 252}Cf spontaneous fission neutron source. The spectra were taken with and without a Cd envelope on the detector dipstick, with different thicknesses of plastic used to slow down neutrons. We have analyzed the complex 595.8 keV gamma peak, as well as several more gamma peaks following the neutron interactions in the detector itself and surroundings materials. The investigation shows that some changes of the initial neutron spectra can be monitored by the analysis of the 595.8 keV gamma peak. We have found good agreement in the intensity changes between the long-tail component of the 595.8 keV and the 691 keV gamma peak ({sup 72}Ge(n,n′){sup 72}Ge reaction), usually used for the estimation of the fast neutron fluence. Results also suggest that the thermal neutrons can have a stronger influence on creation of the Gaussian-like part of 595.8 keV peak, than on the 139 keV one following {sup 74}Ge(n,γ){sup 75m}Ge reaction and used in the standard methods (Škoro et al., 1992) [8] for determination of the thermal neutron flux.

DNA damage and mutagenesis of lambda phage induced by gamma-rays

International Nuclear Information System (INIS)

Bertram, Heidi

1988-01-01

Lambda phage DNA was gamma irradiated in aqueous solution and strand breakage determined. Twice as much minor structural damage per lethal hit was found in this DNA compared with DNA from irradiated phage suspensions. The in vitro irradiated DNA was repackaged into infectious particles. Induction of mutations in the cI or cII cistron was scored using SOS-induced host cells. In vitro prepared particles were found to have second-order kinetics for mutagenesis induced by gamma rays indicating two pre-mutational events were necessary to produce a mutation, but bacteria-free phage suspensions ('lys-phage') showed single hit kinetics for mutagenesis after irradiation. Increase in the mutation rate in the phage particles was mainly due to minor lesions, i.e. ssb, als and unidentified base damage. In lys-phage, mutagenesis might be enhanced by clustered DNA damage - configuration not existing in pack-phage. Loss of infectivity was analysed in comparison with structural damage. All lesions contributed to biological inactivation. Minor lesions were tolerated by lambda phage to a limited extent. Major lesions (e.g. dsb) contributed most to infectivity loss and were considered lethal events. (U.K.)

Background radiation accumulation and lower limit of detection in thermoluminescent beta-gamma dosimeters used by the centralized external dosimetry system

International Nuclear Information System (INIS)

Sonder, E.; Ahmed, A.B.

1991-12-01

A value for ''average background radiation'' of 0.75 mR/week has been determined from a total of 1680 thermoluminescent dosimeters (TLD's) exposed in 70 houses for periods up to one year. The distribution of results indicates a rather large variation among houses, with a few locations exhibiting backgrounds double the general average. Some discrepancies in the short-term background accumulation of TLD's have been explained as being due to light leakage through the dosimeter cases. In addition the lower limit of detection (L D ) for deep and shallow dose equivalents has been determined for these dosimeters. The L D for occupational exposure depends strongly on the time a dosimeter is exposed to background radiation in the field. The L D can vary from a low of 2.4 mrem for high energy gamma rays when the background accumulation period is less than a few weeks to values as high as 66 mrem for uranium beta particles when background has been allowed to accumulate for more than 21 weeks

Influence of UV and Gamma radiations on the induced birefringence of stretched poly(vinyl) alcohol foils

Science.gov (United States)

Nechifor, Cristina-Delia; Zelinschi, Carmen Beatrice; Dorohoi, Dana-Ortansa

2014-03-01

The aim of our paper is to evidence the influence of Gamma and UV radiations on the induced birefringence of poly(vinyl alcohol) stretched foils. Thin foils of PVA were prepared and dried without modifying their surfaces. The polymeric foils were irradiated from 15 min to 6 h using UV and Gamma radiations. The induced by stretching under heating birefringence of PVA films was measured at λ = 589.3 nm with a Babinet Compensator. Physico-chemical processes (photo stabilization, photo degradation, oxidation) induced by irradiation of polymer matrix influence both the stretching degree and the anisotropy of etired foils. An increase of birefringence versus the stretching ratio of the PVA foils was evidenced for all studied samples. The dependence of the birefringence on the exposure time, stretching ratio and nature of radiation was also confirmed.

Detection of SNM by delayed gamma rays from induced fission

International Nuclear Information System (INIS)

Rennhofer, H.; Crochemore, J.-M.; Roesgen, E.; Pedersen, B.

2011-01-01

The Pulsed Neutron Interrogation Test Assembly (PUNITA) is an experimental device for research in NDA methods and field applicable instrumentation for nuclear safeguards and security applications. PUNITA incorporates a standard 14-MeV (D-T) pulsed neutron generator inside a large graphite mantle. The generator target is surrounded by a thick tungsten filter with the purpose to increase the neutron output and to tailor the neutron energy spectrum. In this configuration a sample may be exposed to a relatively high average thermal neutron flux of about (2.2±0.1)x10 3 s -1 cm -2 at only 10% of the maximum target neutron emission. The sample cavity is large enough to allow variation of the experimental setup including the fissile sample, neutron and gamma detectors, and shielding materials. The response from SNM samples of different fissile material content was investigated with various field-applicable scintillation gamma detectors such as the 3x2 in. LaBr 3 detector. Shielding in the form of tungsten and cadmium was applied to the detector to improve the signal to background ratio. Gamma and neutron shields surrounding the samples were also tested for the purpose of simulating clandestine conduct. The energy spectra of delayed gamma rays were recorded in the range 100 keV-9 MeV. In addition time spectra of delayed gamma rays in the range 3.3-8 MeV were recorded in the time period of 10 ms-120 s after the 14-MeV neutron burst. The goal of the experiment was to optimize the sample/detector configuration including the energy range and time period for SNM detection. The results show, for example, that a 170 g sample of depleted uranium can be detected with the given setup in less than 3 min of investigation. Samples of higher enrichment or higher mass are detected in much shorter time.

The muon veto of the Dortmund low-background facility

Energy Technology Data Exchange (ETDEWEB)

Gerhardt, Marcel; Goessling, Claus; Kroeninger, Kevin; Nitsch, Christian [TU Dortmund, Physik EIV, D-44221 Dortmund (Germany)

2016-07-01

The Dortmund Low Background Facility (DLB) is a low-background gamma-ray spectrometry system with an artificial overburden built at ground level. It uses a high-purity germanium detector with a relative efficiency of 60 %, which is set up inside a massive shielding. The outer shielding consists of barite concrete and cast iron, corresponding to ten meters of water equivalent (mw.e.), and houses a multi-layer lead castle as an inner shielding, that features borated polyethylene as a neutron absorber. Additionally an active muon veto is installed to reduce cosmic-induced contributions to the spectrum. The remarkably lowered background of the DLB compared to an unshielded spectrometer, allows radio-purity screening measurements for material preselection with sensitivities better than 1 Bq/kg. This talk focusses on the muon veto of the DLB. Its basic concept and its benefits for low-background operation are described. Also its current status of development and future upgrade plans are presented.

[Chinese medicinal monomer and compound for 60Co-gamma-induced spermatogenic disturbance in mice].

Science.gov (United States)

Zhang, Wei-xing; Wang, Hua-li; Wang, Rui; Li, Rui; He, Wei; Zhang, Tian-biao

2010-05-01

To explore the effects of the monomer and compound of the Chinese herbal drugs resveratrol, lycium barbarum polysaccharide (LBP) and icariin on 60Co-gamma-induced spermatogenic disturbance in mice based on the theory of modern Chinese medicine. A total of 105 male Kunming mice were randomly divided into seven groups, with 15 in each. Group A were normally raised and Groups B, C, D, E, F and G irradiated by 60Co-gamma 6 Gy followed by 60Co-gamma 4 Gy at the interval of 7 days. A week later, Groups C, D, E, F and G received intragastrically the suspension of resveratrol, resveratrol + LBP, resveratrol + icariin, resveratrol + LBP + icariin and resveratrol + LBP + icariin + L-carnitine, respectively, at the dose of 80 mg/(kg x d) for 60 days. The general condition, physical signs and body weight changes of the mice were recorded, and 24 hours after the intragastric medication, their testes were harvested to obtain the testicular weight and indexes, the levels of FSH, LH, T and E2 determined by ELISA, the T/E2 ratio calculated, and the histology of the testis tissues observed under the microscope. The testicular indexes of the mice were decreased by radiation-induced damage, but restored to some extent after intragastric medication, especially in Groups E, F and G. The levels of FSH, LH and T were obviously improved by LBP. The T level and testis weight were increased by Icariin. The level of T/E2 was elevated in Groups E, F and G. The best results were achieved in Group F, which exhibited almost complete recovery from reproductive endocrine disorder and spermatogenic damage. The Chinese medicinal monomer is effective for 60Co-gamma-induced spermatogenic disturbance in mice, and the compound suspension of resveratrol + LBP + icariin produces the best result.

Study, simulation and modelling of a gamma photon detector placed on an integral-type eccentric orbit

International Nuclear Information System (INIS)

Diallo, N.

1999-01-01

Gamma-ray lines are the signature of nuclear reactions and other high-energy processes that take place in the Universe. Their measurement and study provide invaluable information on many important problems in high energy astrophysics, including particle acceleration, physics of compact objects and nucleosynthesis. However the observation of astronomical gamma-ray sources has to be performed above the atmosphere because the Earth's atmosphere is opaque to gamma-rays. Unfortunately at these altitudes, spatial high energy electromagnetic radiation (X and gamma rays) detectors are exposed to intense parasite fluxes of radiation and particles induced by primary galactic cosmic rays. These fluxes as well radiation and secondary particles they generate, constitute a considerable source of background which limits their performances. Our study has been done in the framework of the INTEGRAL mission, a gamma-ray astronomy mission of the European Space Agency. INTEGRAL is devoted to the observation of celestial gamma-ray sources. It consists of two main instruments: an imager IBIS and a high resolution germanium spectrometer SPI (ΔE/E = 1.6 10 -3 at 1.3 MeV). We studied the hadronic component of the SPI background. This component is due to the radioactive decay of unstable nuclides produced by the interactions of cosmic-ray protons with the materials of SPI. It consists of a continuum with gamma ray lines superimposed. To study nuclear processes, Monte Carlo simulations have been performed with the nuclear code TIERCE developed at CEA/DAM. We used the GEANT Monte Carlo code developed at CERN to simulate the germanium detectors response. Background reduction techniques as PSD (Pulse Shape Discrimination) and energetic signatures have been applied in well chosen energy ranges to reduce the background. and improve the SPI sensitivity. With the estimated SPI narrow-line sensitivity level, SPI would be able to detect many gamma ray limes emitted in the active galactic sites

Specific Oral Tolerance Induction Using IFN-Gamma in 2 Cases of Food-Dependent Exercise-Induced Anaphylaxis

Directory of Open Access Journals (Sweden)

Geunwoong Noh

2013-01-01

Full Text Available Anaphylaxis induced by exercise after the intake of certain foods is referred to as food-dependent exercise-induced anaphylaxis (FDEIA. Only the preventive medication such as oral sodium cromoglycate and oral combined cetirizine-montelukast was tried in FDEIA. Specific oral tolerance induction (SOTI using IFN-gamma was tried in 2 cases of FDEIA for wheat. Merely, exercise accompanied every treatment just after the intake of allergenic foods during treatment. Patients acquired tolerance for wheat in both cases successfully. After treatment, two patients take wheat in their food living freely. Conclusively, SOTI using IFN-gamma was effective as the causative treatment for allergenic foods in FDEIA.

An Analysis on Some Factors Which Affect the Energy Resolution of a Low-background Anti-compton HPGe Gamma-ray Spectrometer

International Nuclear Information System (INIS)

Zhou Chunlin; Dai Junjie; Lei Junniu; Zhang Jiaoyu

2009-01-01

This paper describes the basic construction and performing theory of a set of low-background anti-compton high purity germanium gamma-ray spectrometer. On the basis of experiments, some factors which affect the energy resolution of the system are discussed. The optimum parameters configuration for the system is presented and it provides a decision-making ground for purchasing, installation and alignment of analogous system. (authors)

The Protective Role of Tempol Against Oxidative Stress-Related Renal Impairment Induced by Gamma Rays in Rats

International Nuclear Information System (INIS)

Mekawy, H.M.S.; Elkhouly, W.A.; Tawfik, S.S.

2015-01-01

Tempol (4-hydroxy-2,2,6,6-tetramethyl-piperidine-1 oxyl) is a naturally occurring substance that counteracts the harmful and damaging effects of oxidation in animal tissues and has been reported to permeate the biological membranes. In this study, tempol with dose of 18 mg/kg/day for 2 weeks has been shown to be effective in preventing several of the adverse consequences of oxidative stress and inflammation that underlie radiation damage. Adult rats were exposed to a total dose of 6 Gy gamma rays to determine the protective role of tempol on the biochemistry of the injured kidney because gamma rays displayed significant augmentation in renal oxidative modifications markers.The results indicated that plasma renal function tests; urea (Ur), creatinine (Cr), uric acid (UA) and sodium (Na), and plasma renal tubular injury markers; γ -glutamyltransferase ( γ -GT), aspartate aminotransferase (AST), creatine phosphokinase (CPK) and lactate dehydrogenase (LDH), were increased significantly in gamma rays group. In addition, the renal oxidative stress parameters; malondialdehyde (MDA), total cholesterol (TC) and protein carbonyl (PC), were increased significantly, and reduced glutathione (GSH) was decreased significantly in gamma rays group. Moreover, the levels of renal antioxidant enzymes; superoxide dismutase (SOD) and catalase (CAT), were decreased significantly, and myeloperoxidase (MPO) was in creased significantly in gamma rays group.The antioxidant treatment with tempol ameliorates gamma rays-induced biochemical alterations and dysfunction of kidney.Tempol, at levels within tolerable nutritional strategy, reduced the oxidative modification-related renal impairment induced by gamma radiation in rats.

The meiotic consequences of chromosomal aberrations induced by separate and simultaneous applications of gamma rays and NMU in lentil (Lens culinaris Med.)

International Nuclear Information System (INIS)

Dixit, Pratibha; Dubey, D.K.

1983-01-01

Certain meiotic abnormalities were induced by the application of 5, 10 or 15 Kr of gamma rays and/or 0.02 percent of NMU on seeds of lentil (Lens culinaris Med.) var. T36. Univalents, quadrivalents or higher multivalent associations were induced by gamma rays individually or in combination with NMU, while no such associations were recorded in plants treated with NMU alone. But nucleolar fragmentation, chromatin bridges and non-orientation of chromosome fragments were induced by both the mutagens. The percentage of cells showing meiotic abnormalities in the gamma ray treatments increased with an increase in the irradiation dose, however, the combined treatments of the two mutagens did not show a synergestic influence of the two mutagens in inducing such abnormalities. (author)

Spectroscopic evaluation of painted layer structural changes induced by gamma radiation in experimental models

International Nuclear Information System (INIS)

Manea, Mihaela M.; Moise, Ioan V.; Virgolici, Marian; Negut, Constantin D.; Barbu, Olimpia-Hinamatsuri; Cutrubinis, Mihalis; Fugaru, Viorel; Stanculescu, Ioana R.; Ponta, Corneliu C.

2012-01-01

The degradation of cultural heritage objects by insects and microorganisms is an important issue for conservators, art specialists and humankind in general. Gamma irradiation is an efficient method of polychrome wooden artifacts disinfestation. Color changes and other modifications in the physical chemical properties of materials induced by gamma irradiation are feared by cultural heritage responsible committees and they have to be evaluated objectively and precisely. In this paper FTIR and FT-Raman spectroscopy methods were used to investigate the structural changes in some experimental models of tempera paint layers on wood following 11 kGy gamma irradiation at two dose rates. Radiation chemistry depends on the particular pigment, matrix formed by protein, resin (in case of varnished samples) and water presence. For the majority of painted layer in experimental models very small spectral variations were observed. Small changes in the FTIR spectra were observed for the raw sienna experimental model: for the higher dose rate the egg yolk protein oxidation peaks and the CH stretching bands due to lipids degradation products increased. - Highlights: ► Experimental models of tempera paint layers on wood were γ-irradiated at two dose rates. ► Changes induced by γ-irradiation were evaluated by vibrational spectroscopy. ► Minor spectral variations of painted layer were observed. ► Raw sienna FTIR spectra showed little changes of egg yolk and lipids at higher dose rate. ► Gamma irradiation is recommended for disinfection of painted wooden artifacts.

Production of plastified wood with stronger static bending strength means of polymerization induced by gamma radiation

International Nuclear Information System (INIS)

Silva Filho, Elias

1999-01-01

The use of gamma radiation to obtain wood-polymer composites is one of the applications of radiation that presents the most commercial interest. The process, denominated radiopolymerization, comprises the impregnation of monomers into the completely dried wood followed by exposure to gamma radiation to induce polymerization of the impregnated monomers. I this context, the present work aimed the application of this process to seven kinds of wood existing in the brazilian forests. The considered monomer is styrene and the gamma source is Cobalt-60. The obtained wood-polystyrene composites were found to have stronger static bending strength. (author)

Determination of total fluorine in five coal reference materials by proton-induced gamma-ray emission spectrometry

Energy Technology Data Exchange (ETDEWEB)

Roelandts, I.; Robaye, G.; Delbrouck-Habaru, J.M.; Weber, G. [University of Liege, Sart (Belgium). Dept. of Geology, Petrology and Geochemistry

1996-03-01

The direct non-destructive proton-induced gamma-ray emission (PIGE) technique with a germanium detector was applied to the determination of total fluorine concentration in five coal reference materials (BCR 30, NIST 1632b, NIST 1635, SARM 20 and USGS CLB-1). Duplicate analyses were made from five randomly selected bottles of each coal. Individual data are presented and some problems (calibration, proton stopping power, effects of sample heating by the proton beam, background estimation) which were encountered during this study are discussed. Sensitivity and reproducibility of the determinations, and homogeneity of the coal samples with respect to fluorine contents by analysis of variance were investigated. The present data are also compared with the few published values for these reference samples, including other PIGE data. The use of synthetic standards and spiked samples in the present study suggested that the PIGE method was more accurate than other techniques.

Analysis of gamma-background measurements in the North Bulgaria made in the period 30 May - 3 Jun 1994

Energy Technology Data Exchange (ETDEWEB)

Miloslavov, V; Stoilova, S [National Centre of Radiobiology and Radiation Protection, Sofia (Bulgaria)

1996-12-31

Air dose rates from gamma-background radiation has been measured in 42 residential areas in the North Bulgaria. Counting rate data obtained by stationary and portable equipment have been compared. It is concluded that calibration in portable conditions leads to a high standard deviation in the measurements. Calibration with different control sources yields different results although the counting rate does not change. The average air dose rate in different locations is within the range 7.7 - 21.9 {mu}R/h. 5 refs., 4 tabs.

Use of gamma radiation in floriculture industry for development of new varieties through induced mutation

International Nuclear Information System (INIS)

Datta, S.K.

2002-01-01

Nuclear radiation (gamma rays) can create changes in genetic make up of plant material through mutation. Gamma ray induced mutation is now an established method for crop improvement. It is well known that the crops which are propagated vegetatively are very suitable for the application of mutation breeding methods. In floriculture industry there is always demand and necessity of new and novel ornamental varieties. Flower colour and shape are the most important components of novelties. Gamma rays have been most successfully use to produce quite a large number of new promising,varieties in different ornamental (Bougainvillea - 4, Perennial portulaca-6, Chrysanthemum-43, Hibiscus-1, Rose-16, Tuberose-2, Lantana depressa-3 etc.) plants by bringing about genetic changes at Floriculture Section, National Botanical Research. Institute, Lucknow, India. Research carried out covers radiosensitivity, selection of materials, methods of exposure to gamma rays, suitable dose of gamma rays, detection of mutants, isolation of mutants and commercial exploitation of mutants. A good number of mutant varieties have been well accepted in the floriculture industry. The mutant varieties are with new flower colour and shape. More than three decades of applied mutation breeding work has now established beyond doubt that mutation breeding will constitute an excellent supplement to the conventional methods for development of new varieties . Detection of somatic, mutations in flower colour/shape in different vegetative generations (M 1 V 1 , M 1 V 2 , M 1 V 3 and even in later vegetative generations), mutation frequency and spectrum relationship with dose of gamma radiation have been precisely determined. Studies have clearly proved that mutation breeding technique can be exploited for the creation of new and novel ornamental cultivars of commercial importance by inducing genetic variation in already adapted, modern genotypes and can also enrich the germplasm of ornamental horticulture

Measuring the energies and multiplicities of prompt gamma-ray emissions from neutron-induced fission of $^{235}$U using the STEFF spectrometer

CERN Document Server

AUTHOR|(CDS)2093036; Smith, Alastair Gavin; Wright, Tobias James

Following a NEA high priority nuclear data request, an experimental campaign to measure the prompt $\\gamma$-ray emissions from $^{235}$U has been performed. This has used the STEFF spectrometer at the new Experimental Area 2 (EAR2) within the neutron timeof-flight facility (n_TOF), a white neutron source facility at CERN with energies from thermal to approximately 1 GeV. Prior to the experimental campaign, STEFF has been optimised for the environment of EAR2. The experimental hall features a high background $\\gamma$-ray rate, due to the nature of the spallation neutron source. Thus an investigation into reduction of the background $\\gamma$-ray rate, encountered by the NaI(Tl) detector array of STEFF, has been carried out. This has been via simulations using the simulation package FLUKA. Various materials and shielding geometries have been investigated but the effects determined to be insufficient in reducing the background rate by a meaningful amount. The NaI(Tl) detectors have been modified to improve their ...

$\\gamma$-ray energy spectra and multiplicities from the neutron-induced fission of $^{235}$U using STEFF

CERN Document Server

An experiment is proposed to use the STEFF spectrometer at n_TOF to study fragment $\\gamma$-correlations following the neutron-induced fission of $^{235}$U. The STEFF array of 12 NaI detectors will allow measurements of the single $\\gamma$-energy, the $\\gamma$ multiplicity, and the summed $\\gamma$energy distributions as a function of the mass and charge split, and deduced excitation energy in the fission event. These data will be used to study the origin of fission-fragment angular momenta, examining angular distribution eects as a function of incident neutron energy. The principal application of this work is in meeting the NEA high-priority request for improved $\\gamma$ray data from $^{235}$U(n; F). To improve the detection rate and expand the range of detection angles, STEFF will be modied to include two new ssion-fragment detectors each at 45 to the beam direction.

Influence of turmeric on biochemical disorders induced by exposure to gamma- rays or chloropyrifos pesticide on rats

International Nuclear Information System (INIS)

Kamal El-Dein, E.M.; Ebrahim, R.M.

2013-01-01

Toxicity of Chloropyrifos and gamma-radiation exposure on rats were examined in the presence or absence of Turmeric (200 mg/ kg/ b.wt.). Effects chloropyrifos when administrated orally to rats at a dose 9 mg/ kg b .wt (1/ 4 LD 50) for 7 and 28 days showed increased level of malondialdehyde (MDA) concomitant with depletion in the levels of glutathion (GSH), superoxide dismutase (SOD) and catalase (CAT).gamma- radiation exposure effect on rats was examined in the presence or absence of turmeric . Exposure of rats to gamma-radiation (8 Gy) at a fractionated dose levels (2 Gy/ week for 4 weeks) exhibited an elevated level of MDA and decreased level of GSH, SOD and CAT. Administration of Turmeric to animals which were previously treated with Chloropyrifos or gamma-rays showed an amelioration response to the antioxidant regime. Treatment of rats with Chloropyrifos for 7 and 28 days or gamma- radiation induced an elevated serum transaminases level(ALT and AST),Alkaline phosphatase (ALP) and Acid phosphatase activity (ACP), creatinine concentration, blood urea and uric acid.Also treatment of rats with Chloropyrifos for 7 and 28 days or gamma-radiation induced a decline in the testosterone level associated with alteration in the levels of follicular stimulating hormone (FSH),Iuetinizing hormone (LH) and prolactin (PRL).Results observed due to Chloropyrifos pesticide or radiation-exposure have been ameliorated by turmeric administration. It could be concluded that turmeric might protect from oxidative stress

Gamma ray astronomy

International Nuclear Information System (INIS)

Hillier, R.

1984-01-01

The book reviews the development of gamma ray astronomy over the past twenty five years. A large section of the book is devoted to the problems of background radiation and the design of detectors. Gamma rays from the sun, the galactic disc, the galaxy, and extra galactic sources; are also discussed. (U.K.)

Monte Carlo simulations of low background detectors

International Nuclear Information System (INIS)

Miley, H.S.; Brodzinski, R.L.; Hensley, W.K.; Reeves, J.H.

1995-01-01

An implementation of the Electron Gamma Shower 4 code (EGS4) has been developed to allow convenient simulation of typical gamma ray measurement systems. Coincidence gamma rays, beta spectra, and angular correlations have been added to adequately simulate a complete nuclear decay and provide corrections to experimentally determined detector efficiencies. This code has been used to strip certain low-background spectra for the purpose of extremely low-level assay. Monte Carlo calculations of this sort can be extremely successful since low background detectors are usually free of significant contributions from poorly localized radiation sources, such as cosmic muons, secondary cosmic neutrons, and radioactive construction or shielding materials. Previously, validation of this code has been obtained from a series of comparisons between measurements and blind calculations. An example of the application of this code to an exceedingly low background spectrum stripping will be presented. (author) 5 refs.; 3 figs.; 1 tab

PPAR{alpha} deficiency augments a ketogenic diet-induced circadian PAI-1 expression possibly through PPAR{gamma} activation in the liver

Energy Technology Data Exchange (ETDEWEB)

Oishi, Katsutaka, E-mail: k-ooishi@aist.go.jp [Biological Clock Research Group, Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki (Japan); Uchida, Daisuke [Biological Clock Research Group, Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki (Japan); Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki (Japan); Ohkura, Naoki [Department of Clinical Molecular Biology, Faculty of Pharmaceutical Sciences, Teikyo University, Sagamihara, Kanagawa (Japan); Horie, Shuichi [Department of Clinical Biochemistry, Kagawa Nutrition University, Sakado, Saitama (Japan)

2010-10-15

Research highlights: {yields} PPAR{alpha} deficiency augments a ketogenic diet-induced circadian PAI-1 expression. {yields} Hepatic expressions of PPAR{gamma} and PCG-1{alpha} are induced by a ketogenic diet. {yields} PPAR{gamma} antagonist attenuates a ketogenic diet-induced PAI-1 expression. {yields} Ketogenic diet advances the phase of circadian clock in a PPAR{alpha}-independent manner. -- Abstract: An increased level of plasminogen activator inhibitor-1 (PAI-1) is considered a risk factor for cardiovascular diseases, and PAI-1 gene expression is under the control of molecular circadian clocks in mammals. We recently showed that PAI-1 expression is augmented in a phase-advanced circadian manner in mice fed with a ketogenic diet (KD). To determine whether peroxisome proliferator-activated receptor {alpha} (PPAR{alpha}) is involved in hypofibrinolytic status induced by a KD, we examined the expression profiles of PAI-1 and circadian clock genes in PPAR{alpha}-null KD mice. Chronic administration of bezafibrate induced the PAI-1 gene expression in a PPAR{alpha}-dependent manner. Feeding with a KD augmented the circadian expression of PAI-1 mRNA in the hearts and livers of wild-type (WT) mice as previously described. The KD-induced mRNA expression of typical PPAR{alpha} target genes such as Cyp4A10 and FGF21 was damped in PPAR{alpha}-null mice. However, plasma PAI-1 concentrations were significantly more elevated in PPAR{alpha}-null KD mice in accordance with hepatic mRNA levels. These observations suggest that PPAR{alpha} activation is dispensable for KD-induced PAI-1 expression. We also found that hyperlipidemia, fatty liver, and the hepatic expressions of PPAR{gamma} and its coactivator PCG-1{alpha} were more effectively induced in PPAR{alpha}-null, than in WT mice on a KD. Furthermore, KD-induced hepatic PAI-1 expression was significantly suppressed by supplementation with bisphenol A diglycidyl ether, a PPAR{gamma} antagonist, in both WT and PPAR

Gamma Radiation-Induced Template Polymerization Technique

International Nuclear Information System (INIS)

Siyam, T.

2005-01-01

Gamma radiation induced copolymerization of acrylamide sodiumacrylate (AM-AANa) in the presence and absence of the polymer additive was studied at low monomer concentration(1.4M/l). The results showed that the exponents of the dose rate for the polymerization rate was found to be 1.3 and 1.4 in the absence and in the presence of the polymer additive respectively. The molecular weight of the formed polymer increased by addition of the polymer to the system. In the presence of the polymer the comonomers polymerize on the added polymer. In the absence of the added polymer the comonomers polymerize according to the copolymerization process at the initial stage of the copolymerization. While at high conversion the residual comonomers polymerize on the formed macromolecular chains of the produced polymer. These studies showed that the copolymerization in the presence of added polymer is completely template copolymerization while in the absence of the polymer the copolymerization process is only template process with a high conversion

Prompt Gamma Radiation from Fragments in the Thermal Fission of 235U

International Nuclear Information System (INIS)

Albinsson, H.; Lindow, L.

1970-06-01

Measurements were made on the gamma radiation emitted from fission fragments in slow neutron induced fission of 235 U. The fragments were detected with solid state detectors of the surface barrier type and the gamma radiation with a Nal(Tl) scintillator. Mass selection was used so that the gamma radiation could be measured as a function of fragment mass. Time discrimination between the fission gammas and the prompt neutrons released in the fission process was employed to reduce the background. The gamma radiation emitted during different time intervals after the fission event was studied with the help of a collimator, the position of which was changed along the path of the fission fragments. In this way a decay curve was obtained from which the life-time of one of the gamma-emitting states could be estimated. The relative yield of the gamma-rays was determined as a function of mass for different gamma-ray energy portions and two specific time intervals after the fission events. Comparisons were made with data obtained from 252 Cf-fission. Attention is drawn to some features which seem to be the same in 235 U and 252 Cf-fission

Localization of the gamma-radiation sources using the gamma-visor

Directory of Open Access Journals (Sweden)

Ivanov Kirill E.

2008-01-01

Full Text Available The search of the main gamma-radiation sources at the site of the temporary storage of solid radioactive wastes was carried out. The relative absorbed dose rates were measured for some of the gamma-sources before and after the rehabilitation procedures. The effectiveness of the rehabilitation procedures in the years 2006-2007 was evaluated qualitatively and quantitatively. The decrease of radiation background at the site of the temporary storage of the solid radioactive wastes after the rehabilitation procedures allowed localizing the new gamma-source.

Localization of the gamma-radiation sources using the gamma-visor

International Nuclear Information System (INIS)

Ivanov, K. E.; Ponomaryev-Stepnoi, N. N.; Stepennov, B. S.; Teterin, Y. A.; Teterin, A. Y.; Kharitonov, V. V.

2008-01-01

The search of the main gamma-radiation sources at the site of the temporary storage of solid radioactive wastes was carried out. The relative absorbed dose rates were measured for some of the gamma-sources before and after the rehabilitation procedures. The effectiveness of the rehabilitation procedures in the years 2006-2007 was evaluated qualitatively and quantitatively. The decrease of radiation background at the site of the temporary storage of the solid radioactive wastes after the rehabilitation procedures al lowed localizing the new gamma-source. (author)

Conservative constraints on dark matter from the Fermi-LAT isotropic diffuse gamma-ray background spectrum

Energy Technology Data Exchange (ETDEWEB)

Abazajian, Kevork N.; Agrawal, Prateek; Chacko, Zackaria [Maryland Center for Fundamental Physics, Department of Physics, University of Maryland, College Park, Maryland 20742 (United States); Kilic, Can, E-mail: kev@umd.edu, E-mail: apr@umd.edu, E-mail: zchacko@umd.edu, E-mail: kilic@physics.rutgers.edu [Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854 (United States)

2010-11-01

We examine the constraints on final state radiation from Weakly Interacting Massive Particle (WIMP) dark matter candidates annihilating into various standard model final states, as imposed by the measurement of the isotropic diffuse gamma-ray background by the Large Area Telescope aboard the Fermi Gamma-Ray Space Telescope. The expected isotropic diffuse signal from dark matter annihilation has contributions from the local Milky Way (MW) as well as from extragalactic dark matter. The signal from the MW is very insensitive to the adopted dark matter profile of the halos, and dominates the signal from extragalactic halos, which is sensitive to the low mass cut-off of the halo mass function. We adopt a conservative model for both the low halo mass survival cut-off and the substructure boost factor of the Galactic and extragalactic components, and only consider the primary final state radiation. This provides robust constraints which reach the thermal production cross-section for low mass WIMPs annihilating into hadronic modes. We also reanalyze limits from HESS observations of the Galactic Ridge region using a conservative model for the dark matter halo profile. When combined with the HESS constraint, the isotropic diffuse spectrum rules out all interpretations of the PAMELA positron excess based on dark matter annihilation into two lepton final states. Annihilation into four leptons through new intermediate states, although constrained by the data, is not excluded.

Conservative constraints on dark matter from the Fermi-LAT isotropic diffuse gamma-ray background spectrum

International Nuclear Information System (INIS)

Abazajian, Kevork N.; Agrawal, Prateek; Chacko, Zackaria; Kilic, Can

2010-01-01

We examine the constraints on final state radiation from Weakly Interacting Massive Particle (WIMP) dark matter candidates annihilating into various standard model final states, as imposed by the measurement of the isotropic diffuse gamma-ray background by the Large Area Telescope aboard the Fermi Gamma-Ray Space Telescope. The expected isotropic diffuse signal from dark matter annihilation has contributions from the local Milky Way (MW) as well as from extragalactic dark matter. The signal from the MW is very insensitive to the adopted dark matter profile of the halos, and dominates the signal from extragalactic halos, which is sensitive to the low mass cut-off of the halo mass function. We adopt a conservative model for both the low halo mass survival cut-off and the substructure boost factor of the Galactic and extragalactic components, and only consider the primary final state radiation. This provides robust constraints which reach the thermal production cross-section for low mass WIMPs annihilating into hadronic modes. We also reanalyze limits from HESS observations of the Galactic Ridge region using a conservative model for the dark matter halo profile. When combined with the HESS constraint, the isotropic diffuse spectrum rules out all interpretations of the PAMELA positron excess based on dark matter annihilation into two lepton final states. Annihilation into four leptons through new intermediate states, although constrained by the data, is not excluded

Extragalactic gamma-ray background from AGN winds and star-forming galaxies in cosmological galaxy-formation models

Science.gov (United States)

Lamastra, A.; Menci, N.; Fiore, F.; Antonelli, L. A.; Colafrancesco, S.; Guetta, D.; Stamerra, A.

2017-10-01

We derive the contribution to the extragalactic gamma-ray background (EGB) from active galactic nuclei (AGN) winds and star-forming galaxies by including a physical model for the γ-ray emission produced by relativistic protons accelerated by AGN-driven and supernova-driven shocks into a state-of-the-art semi-analytic model of galaxy formation. This is based on galaxy interactions as triggers of AGN accretion and starburst activity and on expanding blast waves as the mechanism to communicate outwards the energy injected into the interstellar medium by the active nucleus. We compare the model predictions with the latest measurement of the EGB spectrum performed by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope (Fermi) in the range between 100 MeV and 820 GeV. We find that AGN winds can provide 35 ± 15% of the observed EGB in the energy interval Eγ = 0.1-1 GeV, for 73 ± 15% at Eγ = 1-10 GeV, and for 60 ± 20% at Eγ ≳10 GeV. The AGN wind contribution to the EGB is predicted to be larger by a factor of 3-5 than that provided by star-forming galaxies (quiescent plus starburst) in the hierarchical clustering scenario. The cumulative γ-ray emission from AGN winds and blazars can account for the amplitude and spectral shape of the EGB, assuming the standard acceleration theory, and AGN wind parameters that agree with observations. We also compare the model prediction for the cumulative neutrino background from AGN winds with the most recent IceCube data. We find that for AGN winds with accelerated proton spectral index p = 2.2-2.3, and taking into account internal absorption of γ-rays, the Fermi-LAT and IceCube data could be reproduced simultaneously.

Lymphocytes from wasted mice express enhanced spontaneous and {gamma}-ray-induced apoptosis

Energy Technology Data Exchange (ETDEWEB)

Woloschak, G.E. [Argonne National Lab., IL (United States)]|[Loyola Univ. Medical Center, Maywood, IL (United States); Chang-Liu, Chin-Mei [Argonne National Lab., IL (United States); Chung, Jen; Libertin, C.R. [Loyola Univ. Medical Center, Maywood, IL (United States)

1993-09-01

Mice bearing the autosomal recessive mutation wasted (wst/wst) display a disease pattern including faulty repair of DNA damage in lymphocytes after radiation exposure, neurologic abnormalities, and immunodeficiency. Many of the features of this mouse model have suggested a premature or increased spontaneous frequency of apoptosis in thymocytes; past work has shown an inability to establish cultured T cell lines, an abnormally high death rate of stimulated T cells in culture, and an increased sensitivity of T cells to the killing effects of ionizing radiations in wst/wst mice relative to controls. The experiments reported here were designed to examine splenic and thymic lymphocytes from wasted and control mice for signs of early apoptosis. Our results revealed enhanced expression of Rp-8 mRNA (associated with apoptosis) in thymic lymphocytes and reduced expression in splenic lymphocytes of wst/wst mice relative to controls; expression of Rp-2 and Td-30 mRNA (induced during apoptosis) were not detectable in spleen or thymus. Higher spontaneous DNA fragmentation was observed in wasted mice than in controls; however, {gamma}-ray-induced DNA fragmentation peaked at a lower dose and occurred to a greater extent in wasted mice relative to controls. These results provide evidence for high spontaneous and {gamma}-ray-induced apoptosis in T cells of wasted mice as a mechanism underlying the observed lymphocyte and DNA repair abnormalities.

Recording {gamma} spectrometer with elimination of compton background; Spectrographe {gamma} enregistreur avec elimination du bruit de fond compton

Energy Technology Data Exchange (ETDEWEB)

Julliot, C [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

This instrument, derived from the recording {gamma} spectrograph, gives better definition of photoelectric peaks by elimination of pulses caused by {gamma} photons incompletely absorbed in the scintillator (Compton effect). This system uses an original method devised by Peirson: the spectrum, devoid of photoelectric peak, supplied by a detector equipped with an anthracene scintillator, is cut off from the spectrum provided by a conventional detector equipped with a Nal (T1) scintillator. The regulation of the mechanical system, detector support and source allows the detection yields to be adjusted. The electronic system is identical in presentation with that of the recording spectrograph. (author) [French] Cet appareil derive du spectrographe {gamma} enregistreur permet d'obtenir une meilleure definition des pics photoelectriques, par elimination des impulsions provenant des photons {gamma} incompletement absorbes dans le scintillateur (effet Compton). Cet ensemble met en oeuvre une methode originale due a Peirson: le spectre, depourvu de pic photoelectrique, fourni par un detecteur, equipe avec un scintillateur d'anthracene, est retranche du spectre donne par un detecteur classique, equipe avec un scintillateur de NaI (T1). Le reglage de l'ensemble mecanique, support des detecteurs et de la source, permet d'ajuster les rendements de detection. L'ensemble electronique se presente sous un aspect identique a celui du spectrographe enregistreur. (auteur)

Improvement of passive shielding to reduce background components to determinate radioactivity at low energy gamma rays

Energy Technology Data Exchange (ETDEWEB)

Thanh, Tran Thien [VNUHCM-Univ. of Science, Ho Chi Minh City (Viet Nam). Dept. of Nuclear Engineering Physics; Ton Duc Thang Univ., Ho Chi Minh City (Viet Nam). Div. of Nuclear Physics; Loan, T.T.H.; Nhon, M.V.; Tao, C.V. [VNUHCM-Univ. of Science, Ho Chi Minh City (Viet Nam). Dept. of Nuclear Engineering Physics

2014-06-15

This paper describes a new system that has the ability to reduce background components to apply for environmental studies. This system uses gamma spectrometry with semi-empirical self-absorption correction and practical method for routine measurements of the mass activity radionuclides at low energy such as {sup 210}Pb (46.5 keV), {sup 234}Th (63.3 keV) and {sup 226}Ra (186.2 keV). The reliability and precision of proficiency test must pass for final scores all the analytical determinations of received ''acceptable'' for all radionuclides. Our work shows an experiment developed for the calculation of self-absorption correction in that case that the sample's chemical composition is unknown.

An Overview of the XGAM Code and Related Software for Gamma-ray Analysis

Energy Technology Data Exchange (ETDEWEB)

Younes, W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2014-11-13

The XGAM spectrum-fitting code and associated software were developed specifically to analyze the complex gamma-ray spectra that can result from neutron-induced reactions. The XGAM code is designed to fit a spectrum over the entire available gamma-ray energy range as a single entity, in contrast to the more traditional piecewise approaches. This global-fit philosophy enforces background continuity as well as consistency between local and global behavior throughout the spectrum, and in a natural way. This report presents XGAM and the suite of programs built around it with an emphasis on how they fit into an overall analysis methodology for complex gamma-ray data. An application to the analysis of time-dependent delayed gamma-ray yields from ²³⁵U fission is shown in order to showcase the codes and how they interact.

In vivo persistence of sister chromatid exchanges (SCE) induced by gamma rays in mouse bone marrow cells

International Nuclear Information System (INIS)

Morales-Ramirez, P.; Vallarino-Kelly, T.; Rodriguez-Reyes, R.

1984-01-01

The sister chromatid exchange (SCE) frequencies induced in bone marrow cells by in vivo irradiation with gamma rays before or after bromodeoxyuridine (BrdUrd) incorporation were compared. The frequency of SCE at different postirradiation times was also measured in bone marrow cells in vivo, irradiated before BrdUrd incorporation. Increased sensitivity to SCE induction by radiation was found in cells after BrdUrd incorporation for one cycle when compared with cells irradiated before BrdUrd incorporation. The increased SCE frequency persisted for at least 72 hr after the initial irradiation, implying that the gamma ray-induced lesion(s) capable of eliciting an SCE are persistent and cannot be easily repaired

Study, simulation and modelling of a gamma photon detector placed on an integral-type eccentric orbit; Etude, simulation et modelisation d'un detecteur de photons gamma place sur une orbite excentrique de type integral

Energy Technology Data Exchange (ETDEWEB)

Diallo, N

1999-07-01

Gamma-ray lines are the signature of nuclear reactions and other high-energy processes that take place in the Universe. Their measurement and study provide invaluable information on many important problems in high energy astrophysics, including particle acceleration, physics of compact objects and nucleosynthesis. However the observation of astronomical gamma-ray sources has to be performed above the atmosphere because the Earth's atmosphere is opaque to gamma-rays. Unfortunately at these altitudes, spatial high energy electromagnetic radiation (X and gamma rays) detectors are exposed to intense parasite fluxes of radiation and particles induced by primary galactic cosmic rays. These fluxes as well radiation and secondary particles they generate, constitute a considerable source of background which limits their performances. Our study has been done in the framework of the INTEGRAL mission, a gamma-ray astronomy mission of the European Space Agency. INTEGRAL is devoted to the observation of celestial gamma-ray sources. It consists of two main instruments: an imager IBIS and a high resolution germanium spectrometer SPI ({delta}E/E = 1.6 10{sup -3} at 1.3 MeV). We studied the hadronic component of the SPI background. This component is due to the radioactive decay of unstable nuclides produced by the interactions of cosmic-ray protons with the materials of SPI. It consists of a continuum with gamma ray lines superimposed. To study nuclear processes, Monte Carlo simulations have been performed with the nuclear code TIERCE developed at CEA/DAM. We used the GEANT Monte Carlo code developed at CERN to simulate the germanium detectors response. Background reduction techniques as PSD (Pulse Shape Discrimination) and energetic signatures have been applied in well chosen energy ranges to reduce the background. and improve the SPI sensitivity. With the estimated SPI narrow-line sensitivity level, SPI would be able to detect many gamma ray limes emitted in the active

Gamma radiation inhibits the appearance of induced ornithine decarboxylase activity in Chinese hamster cells

International Nuclear Information System (INIS)

Ben-Hur, E.; Heimer, Y.M.; Riklis, E.

1981-01-01

Ornithine decarboxylase activity of Chinese hamster cells (ODC, EC 4.1.1.17) can be induced in plateau phase by change of medium. Exposure of the cells to gamma radiation before induction reduces the amount of ODC activity induced. The dose-response curve is exponential with a D 0 of 106 krad. Exposure of BUdR-substituted cells is more effective in reducing ODC induction at high doses, with a D 0 of 38 krad. Cells can recover from the reduction incurred by 74 krad if enzyme induction is delayed for 2 hours after exposure. Treatment of the cells with psoralen-plus-light completely inhibits RNA synthesis without affecting protein synthesis (Heimer, Ben-Hur and Riklis 1977, 1978). Using this procedure it is shown that the effect of gamma radiation on inducible ODC activity is due not only to DNA damage but also involves a post-transcriptional effect. This conclusion is supported by employing a heat shock to inhibit protein synthesis prior to gamma-irradiation of log-phase cells. In such cells the increased activity of ODC upon transfer to 37 0 C is due primarily to enzyme synthesis using pre-existing RNA species during the first few hours. A low concentration of actinomycin D, which inhibits rRNA synthesis, applied during the recovery period, prevents the recovery of the cells' capacity for maximal ODC induction. This may indicate that, in order to recover, the cells have to repair damage to the ribosomes as well as to DNA. (author)

Berkeley Low Background Facility

International Nuclear Information System (INIS)

Thomas, K. J.; Norman, E. B.; Smith, A. R.; Poon, A. W. P.; Chan, Y. D.; Lesko, K. T.

2015-01-01

The Berkeley Low Background Facility (BLBF) at Lawrence Berkeley National Laboratory (LBNL) in Berkeley, California provides low background gamma spectroscopy services to a wide array of experiments and projects. The analysis of samples takes place within two unique facilities; locally within a carefully-constructed, low background laboratory on the surface at LBNL and at the Sanford Underground Research Facility (SURF) in Lead, SD. These facilities provide a variety of gamma spectroscopy services to low background experiments primarily in the form of passive material screening for primordial radioisotopes (U, Th, K) or common cosmogenic/anthropogenic products; active screening via neutron activation analysis for U,Th, and K as well as a variety of stable isotopes; and neutron flux/beam characterization measurements through the use of monitors. A general overview of the facilities, services, and sensitivities will be presented. Recent activities and upgrades will also be described including an overview of the recently installed counting system at SURF (recently relocated from Oroville, CA in 2014), the installation of a second underground counting station at SURF in 2015, and future plans. The BLBF is open to any users for counting services or collaboration on a wide variety of experiments and projects

Gamma ray induced sensitization in CaSO4:Dy and competing trap model

International Nuclear Information System (INIS)

Nagpal, J.S.; Kher, R.K.; Gangadharan, P.

1979-01-01

Gamma ray induced sensitization in CaSO 4 :Dy has been compared (by measurement of TL glow curves) for different temperatures during irradiation (25 0 , 120 0 and 250 0 C). Enhanced sensitization at elevated temperatures seems to support the competing trap model for supralinearity and sensitization in CaSO 4 :Dy. (author)

The induced expression of heat shock proteins as a part of the early cellular response to gamma radiation

International Nuclear Information System (INIS)

Stankova, K.; Ivanova, K.; Georgieva, R.; Rupova, I.; Boteva, R.

2008-01-01

A variety of stressful stimuli including gamma radiation can induce increase in the synthesis of heat shock proteins (Hsp). This family of molecular chaperones includes members with molecular masses ranging from 10 to 150 kDa and has been identified in all organisms from bacteria to humans. Hsp70 chaperones are very important. The present study aimed to characterize the radiation-induced changes in Hsp70 synthesis in human lymphocytes as a part of the early cellular response to gamma irradiation. The expression of Hsp70 was determined with Western blot and the radiation-induced apoptotic changes were registered by staining with fluorescent dyes. Part of the experiments were performed in the presence of the organic solvent DMSO. At low concentrations this reagent shows antioxidant activity and can reduce the level of the radiation-induced oxidant stress which determines the predominant biological effects of the ionizing radiation. Irradiation with 0.5 to 8 Gy caused statistically significant increase in the synthesis of Hsp70 which was strongest after irradiation with 4 Gy. In the range 0.5-2 Gy the enhancement of the radiation-induced synthesis of Hsp70 reached 60%. Our experimental results characterize changes in the Hsp70 synthesis after gamma irradiation as a part of the early cellular stress response in lymphocytes. (authors)

Cosmical sources of gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Kuchowicz, B [Warsaw Univ. (Poland)

1974-01-01

A brief historical outline of the X-ray and ..gamma..-ray astronomies is given first, then a summary of the recent status of X-ray astronomy follows. Further chapters include information on ..gamma..-ray sources in the solar system, in our Galaxy, and beyond it. In discussing linear gamma spectra attention is paid to the possibility of studying explosive nucleo-synthesis by observation of gamma lines from supernova remnants, etc. Questions of the isotropic gamma background are discussed at the end of the survey.

Optimization of a neural network model for signal-to-background prediction in gamma-ray spectrometry

International Nuclear Information System (INIS)

Dragovic, S.; Onjia, A. . E-mail address of corresponding author: sdragovic@inep.co.yu; Dragovic, S.)

2005-01-01

The artificial neural network (ANN) model was optimized for the prediction of signal-to-background (SBR) ratio as a function of the measurement time in gamma-ray spectrometry. The network parameters: learning rate (α), momentum (μ), number of epochs (E) and number of nodes in hidden layer (N) were optimized simultaneously employing variable-size simplex method. The most accurate model with the root mean square (RMS) error of 0.073 was obtained using ANN with online backpropagation randomized (OBPR) algorithm with α = 0.27, μ 0.36, E = 14800 and N = 9. Most of the predicted and experimental SBR values for the eight radionuclides ( 226 Ra, 214 Bi, 235 U, 40 K, 232 Th, 134 Cs, 137 Cs and 7 Be), studied in this work, reasonably agreed to within 15 %, which was satisfactory accuracy. (author)

Ways of making-sense: Local gamma synchronization reveals differences between semantic processing induced by music and language.

Science.gov (United States)

Barraza, Paulo; Chavez, Mario; Rodríguez, Eugenio

2016-01-01

Similar to linguistic stimuli, music can also prime the meaning of a subsequent word. However, it is so far unknown what is the brain dynamics underlying the semantic priming effect induced by music, and its relation to language. To elucidate these issues, we compare the brain oscillatory response to visual words that have been semantically primed either by a musical excerpt or by an auditory sentence. We found that semantic violation between music-word pairs triggers a classical ERP N400, and induces a sustained increase of long-distance theta phase synchrony, along with a transient increase of local gamma activity. Similar results were observed after linguistic semantic violation except for gamma activity, which increased after semantic congruence between sentence-word pairs. Our findings indicate that local gamma activity is a neural marker that signals different ways of semantic processing between music and language, revealing the dynamic and self-organized nature of the semantic processing. Copyright © 2015 Elsevier Inc. All rights reserved.

Neurofeedback Effects on Evoked and Induced EEG Gamma Band Reactivity to Drug-related Cues in Cocaine Addiction

Science.gov (United States)

Horrell, Timothy; El-Baz, Ayman; Baruth, Joshua; Tasman, Allan; Sokhadze, Guela; Stewart, Christopher; Sokhadze, Estate

2010-01-01

Introduction Preoccupation with drug and drug-related items is a typical characteristic of cocaine addicted individuals. It has been shown in multiple accounts that prolonged drug use has a profound effect on the EEG recordings of drug addicts when compared to controls during cue reactivity tests. Cue reactivity refers to a phenomenon in which individuals with a history of drug abuse exhibit excessive psychophysiological responses to cues associated with their drug of choice. One of the aims of this pilot study was to determine the presence of an attentional bias to preferentially process drug-related cues using evoked and induced gamma reactivity measures in cocaine addicts before and after biobehavioral treatment based on neurofeedback. Another aim was to show that central SMR amplitude increase and frontal theta control is possible in an experimental outpatient drug users group over 12 neurofeedback sessions. Method Ten current cocaine abusers participated in this pilot research study using neurofeedback combined with Motivational Interviewing sessions. Eight of them completed all planned pre- and post –neurofeedback cue reactivity tests with event-related EEG recording and clinical evaluations. Cue reactivity test represented a visual oddball task with images from the International Affective Picture System and drug-related pictures. Evoked and induced gamma responses to target and non-target drug cues were analyzed using wavelet analysis. Results Outpatient subjects with cocaine addiction completed the biobehavioral intervention and successfully increased SMR while keeping theta practically unchanged in 12 sessions of neurofeedback training. The addition of Motivational Interviewing helped retain patients in the study. Clinical evaluations immediately after completion of the treatment showed decreased self-reports on depression and stress scores, and urine tests collaborated reports of decreased use of cocaine and marijuana. Effects of neurofeedback resulted

Prompt Gamma Radiation from Fragments in the Thermal Fission of {sup 235}U

Energy Technology Data Exchange (ETDEWEB)

Albinsson, H [Chalmers Univ. of Technology, Goteborg (Sweden); Lindow, L [AB Atomenergi, Nykoeping (Sweden)

1970-06-15

Measurements were made on the gamma radiation emitted from fission fragments in slow neutron induced fission of {sup 235}U. The fragments were detected with solid state detectors of the surface barrier type and the gamma radiation with a Nal(Tl) scintillator. Mass selection was used so that the gamma radiation could be measured as a function of fragment mass. Time discrimination between the fission gammas and the prompt neutrons released in the fission process was employed to reduce the background. The gamma radiation emitted during different time intervals after the fission event was studied with the help of a collimator, the position of which was changed along the path of the fission fragments. In this way a decay curve was obtained from which the life-time of one of the gamma-emitting states could be estimated. The relative yield of the gamma-rays was determined as a function of mass for different gamma-ray energy portions and two specific time intervals after the fission events. Comparisons were made with data obtained from {sup 252} Cf-fission. Attention is drawn to some features which seem to be the same in {sup 235}U and {sup 252} Cf-fission.

Frequency and spectrum of mutations induced by gamma irradiation in single, double and triple dwarf wheats

International Nuclear Information System (INIS)

Dhonukshe, B.L.

1981-01-01

Induced mutation studies were carried with three dwarf wheat varieties viz., ''Sonalika'', ''Chhoti Lerma'' and ''Hira'', considered to be single, double and trible dwarfs, respectively. Gamma-rays were used as a source of irradiation. Frequency of chlorophyll mutations were comparatively low and the spectrum was narrow. Chlorophyll mutations were altogether absent in the variety ''Sonalika''. A very wide spectrum of viable mutations affecting stem, leaf, ear growth habit, maturity and fertility characteristics was observed in the M 2 . The cumulative frequency of all the mutants together was quite high, which varied with the varieties. There were varietal differences in the composition and width of the spectrum induced by gamma-rays. The dwarf mutants having desirable leaf and spike characters were isolated in all the three varieties. (author)

On induced action for conformal higher spins in curved background

Energy Technology Data Exchange (ETDEWEB)

Beccaria, Matteo, E-mail: matteo.beccaria@le.infn.it [Dipartimento di Matematica e Fisica Ennio De Giorgi, Università del Salento & INFN, Via Arnesano, 73100 Lecce (Italy); Tseytlin, Arkady A., E-mail: tseytlin@imperial.ac.uk [The Blackett Laboratory, Imperial College, London SW7 2AZ (United Kingdom)

2017-06-15

We continue the investigation of the structure of the action for a tower of conformal higher spin fields in non-trivial 4d background metric recently discussed in Grigoriev and Tseytlin (2016). The action is defined as an induced one from path integral of a conformal scalar field in curved background coupled to higher spin fields. We analyze in detail the dependence of the quadratic part of the induced action on the spin 1 and spin 3 fields, determining the presence of a curvature-dependent mixed spin 1–3 term. One consequence is that the pure spin 3 kinetic term cannot be gauge-invariant on its own beyond the leading term in small curvature expansion. We also compute the non-zero contribution of the 1–3 mixing term to the conformal anomaly c-coefficient. One is thus to determine all such mixing terms before addressing the question of possible vanishing of the total c-coefficient in the conformal higher spin theory.

On induced action for conformal higher spins in curved background

Directory of Open Access Journals (Sweden)

Matteo Beccaria

2017-06-01

Full Text Available We continue the investigation of the structure of the action for a tower of conformal higher spin fields in non-trivial 4d background metric recently discussed in Grigoriev and Tseytlin (2016 [15]. The action is defined as an induced one from path integral of a conformal scalar field in curved background coupled to higher spin fields. We analyze in detail the dependence of the quadratic part of the induced action on the spin 1 and spin 3 fields, determining the presence of a curvature-dependent mixed spin 1–3 term. One consequence is that the pure spin 3 kinetic term cannot be gauge-invariant on its own beyond the leading term in small curvature expansion. We also compute the non-zero contribution of the 1–3 mixing term to the conformal anomaly c-coefficient. One is thus to determine all such mixing terms before addressing the question of possible vanishing of the total c-coefficient in the conformal higher spin theory.

Background current of radioisotope manometer

International Nuclear Information System (INIS)

Vydrik, A.A.

1987-01-01

The technique for calculating the main component of the background current of radioisotopic monometers, current from direct collision of ionizing particles and a collector, is described. The reasons for appearance of background photoelectron current are clarified. The most effective way of eliminating background current components is collector protection from the source by a screen made of material with a high gamma-quanta absorption coefficient, such as lead, for example

Gamma delta T cells promote inflammation and insulin resistance during high fat diet-induced obesity in mice

Science.gov (United States)

Gamma delta T cells are resident in adipose tissue and increase during diet-induced obesity. Their possible contribution to the inflammatory response that accompanies diet-induced obesity was investigated in mice after a 5-10 week high milk fat diet. The high milk fat diet resulted in significant in...

Multiple Gamma-Ray Detection Capability of a CeBr3 Detector for Gamma Spectroscopy

Directory of Open Access Journals (Sweden)

A. A. Naqvi

2017-01-01

Full Text Available The newly developed cerium tribromide (CeBr3 detector has reduced intrinsic gamma-ray activity with gamma energy restricted to 1400–2200 keV energy range. This narrower region of background gamma rays allows the CeBr3 detector to detect more than one gamma ray to analyze the gamma-ray spectrum. Use of multiple gamma-ray intensities in elemental analysis instead of a single one improves the accuracy of the estimated results. Multigamma-ray detection capability of a cylindrical 75 mm × 75 mm (diameter × height CeBr3 detector has been tested by analyzing the chlorine concentration in water samples using eight chlorine prompt gamma rays over 517 to 8578 keV energies utilizing a D-D portable neutron generator-based PGNAA setup and measuring the corresponding minimum detection limit (MDC of chlorine. The measured MDC of chlorine for gamma rays with 517–8578 keV energies varies from 0.07 ± 0.02 wt% to 0.80 ± 0.24. The best value of MDC was measured to be 0.07 ± 0.02 wt% for 788 keV gamma rays. The experimental results are in good agreement with Monte Carlo calculations. The study has shown excellent detection capabilities of the CeBr3 detector for eight prompt gamma rays over 517–8578 keV energy range without significant background interference.

Development of new iraqi wheat varieties induced by gamma rays

International Nuclear Information System (INIS)

Ibrahim, I.F.; Al-Janabi, K.K.; Al-Maaroof, E.M.; Al-Aubaidi, M.O.; Mahmoud, A.H.; Al-Janabi, A.A.

1991-01-01

The aim of the present investigation is to study agronomic traits of three wheat mutants induced by gamma rays and compared with their origin 'Saber Beg' during M 8 - M 11 generations. These mutants showed a moderate resistance to leaf rust and lodging, while the origin was susceptible. Also, these mutants surpassed their origin in seed weight of 100 spikes, weight of 1000 kernels and protein yield per unit area. Chemical and physical analyses of mutant flours indicated that it could be used for bread making successfully.2 fig.,4 tab

Berkeley Low Background Counting Facility

Data.gov (United States)

Federal Laboratory Consortium — Sensitive low background assay detectors and sample analysis are available for non-destructive direct gamma-ray assay of samples. Neutron activation analysis is also...

γ-Ray background sources in the VESUVIO spectrometer at ISIS spallation neutron source

International Nuclear Information System (INIS)

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

2009-01-01

An investigation of the gamma background was carried out in the VESUVIO spectrometer at the ISIS spallation neutron source. This study, performed with a yttrium-aluminum-perovskite (YAP) scintillator, follows high resolution pulse height measurements of the gamma background carried out on the same instrument with the use of a high-purity germanium detector. In this experimental work, a mapping of the gamma background was attempted, trying to find the spatial distribution and degree of directionality of the different contributions identified in the previous study. It is found that the gamma background at low times is highly directional and mostly due to the gamma rays generated in the moderator-decoupler system. The other contributions, consistently to the findings of a previous experiment, are identified as a nearly isotropic one due to neutron absorption in the walls of the experimental hall, and a directional one coming from the beam dump.

γ-Ray background sources in the VESUVIO spectrometer at ISIS spallation neutron source

Science.gov (United States)

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

2009-09-01

An investigation of the gamma background was carried out in the VESUVIO spectrometer at the ISIS spallation neutron source. This study, performed with a yttrium-aluminum-perovskite (YAP) scintillator, follows high resolution pulse height measurements of the gamma background carried out on the same instrument with the use of a high-purity germanium detector. In this experimental work, a mapping of the gamma background was attempted, trying to find the spatial distribution and degree of directionality of the different contributions identified in the previous study. It is found that the gamma background at low times is highly directional and mostly due to the gamma rays generated in the moderator-decoupler system. The other contributions, consistently to the findings of a previous experiment, are identified as a nearly isotropic one due to neutron absorption in the walls of the experimental hall, and a directional one coming from the beam dump.

Statistical analysis for discrimination of prompt gamma ray peak induced by high energy neutron: Monte Carlo simulation study

International Nuclear Information System (INIS)

Do-Kun Yoon; Joo-Young Jung; Tae Suk Suh; Seong-Min Han

2015-01-01

The purpose of this research is a statistical analysis for discrimination of prompt gamma ray peak induced by the 14.1 MeV neutron particles from spectra using Monte Carlo simulation. For the simulation, the information of 18 detector materials was used to simulate spectra by the neutron capture reaction. The discrimination of nine prompt gamma ray peaks from the simulation of each detector material was performed. We presented the several comparison indexes of energy resolution performance depending on the detector material using the simulation and statistics for the prompt gamma activation analysis. (author)

Sister chromatid exchanges in the bone marrow cells of in vivo rats induced by gamma radiation and chemical mutagens

International Nuclear Information System (INIS)

Rodriguez R, R.G.

1981-01-01

Sister chromatid exchanges (SCE) in the bone marrow of in vivo rats induced by gamma radiation doses and by the chemical mutagens, mitomycin C (MMC), cyclophosphamide (CP), and sulphonate-methylmethane (SMM), were studied. The purpose was to evaluate the sensitivity and reproducibility of a simplified SCE in vivo detecting system developed in our laboratory and to compare the results obtained with those reported elsewhere. Simplification consisted in administering the amounts of 5-bromo-2'-deoxyuridine (BrdU) necessary to observe the SCE, after first adsorbing the BrdU in activated carbon and then injecting it interperitoneally, into the rats. The results were a longer time in vivo ADN incorporation without convulsions in the rats, and a reduction in the time course as compared to other methods. We observed a basal rate of 3.6+-0.37 SCE/cell and that: 0.44 Gy of gamma radiation induced 7.7+-0.73 SCE/cell; 1.6 μg/g of MMC induced 8.1+-1.20 SCE/cell; 5 μg/g of CP induced 8.25+-1.5 SCE/cell, 40 μg/g of SMM induced 22.0+-5 SCE/cell and 380 μg/g of sulphonate-ethylmethane induced 8.6+-1.2 SCE/cell. This showed that all the agents were capable of inducing SCE in the bone marrow cells of rats in vivo under our conditions. We noted a greater induced efficiency for gamma radiation than the obtained by other investigators and a relatively similar efficiency in the case of chemical mutagens as reported in other studies. (author)

Background gamma radiation monitoring of three clusters of villages surrounding Mohuldih, Banduhurang and Bagjata villages, the proposed uranium mining areas in Singhbhum, Jharkhand

International Nuclear Information System (INIS)

Chougaonkar, M.P.; Puranik, V.D.; Singh, Prashant

2008-01-01

Generation of power is a fundamental catalyst to the social and economic development of a country. India needs more power in order to have a strong industrial base and for infrastructure development. With this in view, there has been an emphasis on nuclear power as an alternative source in the field of electricity generation as the nuclear power can be an effective tool in reducing stress on the environment. The Singhbhum district in the state of Jharkhand in India has been known to have deposits of uranium and uranium mines like Jaduguda, Narwapahar, Bhatin etc have been operating in the region. With the increased requirement of electricity and hence suitable fuel, few more sites are proposed to mine uranium in the region. The sites proposed are near the villages of Mohuldih, Banduhurang and Bagjata and are proposed to be open cast mines. These areas of Singhbhum are not economically advanced areas. By and large, the population is poor and there are existing problems like malnutrition and poor health. The activities of mining and the associated developments in the region are expected to improve the economic condition of the residents either through direct employment in the mining facilities, or by indirect gains due to infrastructural developments in the region. In order to assess the impact of the mining operations on the environment and the population as well, it is necessary that the pre-operational survey be carried out in the regions in question. As is the practice, a complete pre-operational survey of the physical, chemical and environmental parameters has been carried out in the region. Background gamma radiation survey was also carried out, using the thermo luminescent dosimetry technique, to obtain the preoperational levels prevalent in the regions. This paper gives the results of the baseline background gamma radiation survey in the region. It was observed that the general gamma background levels of the areas, as measured using TLDs, was 1.36 ± 0.41 m

Gamma ray irradiation to roots of tea-plants and induced mutant system

International Nuclear Information System (INIS)

Takeda, Yoshiyuki; Nekaku, Koji; Wada, Mitsumasa

1990-01-01

In order to utilize the useful mutation which is induced by irradiation for the breeding of tea-plants, the gamma-ray irradiation to the roots of tea-plants was carried out. The samples were the roots of tea-plants of four varieties dug up in February, 1984, and were adjusted to about 20 cm, then, put in the cold storage at 5degC for 9 months till the time of irradiation in November, 1984. However, a part of them was taken out in August, and planted in a field for 76 days to germinate, thereafter, used as the samples. The gamma-ray from a Co-60 source was irradiated in the radiation breeding laboratory of Agriculture Bioresources Research Institute at the total dose of 1, 2 and 3 kR and the dose rate of 500 R/h. The irradiated roots were planted as they are or in the state of being cut, and the rate of germination, the number of buds and the induced mutation were examined. Clear difference was not observed in the rate of germination and the number of buds between the irradiated samples and those without irradiation. The long roots were superior to the short roots regarding these items. The types of the induced mutation were mostly thin leaves, and also yellowing, mottling, fascination and so on occurred. The mutant system lacking trichomes on the back of new leaves is considered to be strong against tea anthracnose, and is valuable. (K.I.)

Gamma ray irradiation to roots of tea-plants and induced mutant system

Energy Technology Data Exchange (ETDEWEB)

Takeda, Yoshiyuki; Nekaku, Koji; Wada, Mitsumasa (National Research Inst. of Vegetables, Ornamental Plants and Tea, Ano, Mie (Japan))

1990-11-01

In order to utilize the useful mutation which is induced by irradiation for the breeding of tea-plants, the gamma-ray irradiation to the roots of tea-plants was carried out. The samples were the roots of tea-plants of four varieties dug up in February, 1984, and were adjusted to about 20 cm, then, put in the cold storage at 5degC for 9 months till the time of irradiation in November, 1984. However, a part of them was taken out in August, and planted in a field for 76 days to germinate, thereafter, used as the samples. The gamma-ray from a Co-60 source was irradiated in the radiation breeding laboratory of Agriculture Bioresources Research Institute at the total dose of 1, 2 and 3 kR and the dose rate of 500 R/h. The irradiated roots were planted as they are or in the state of being cut, and the rate of germination, the number of buds and the induced mutation were examined. Clear difference was not observed in the rate of germination and the number of buds between the irradiated samples and those without irradiation. The long roots were superior to the short roots regarding these items. The types of the induced mutation were mostly thin leaves, and also yellowing, mottling, fascination and so on occurred. The mutant system lacking trichomes on the back of new leaves is considered to be strong against tea anthracnose, and is valuable. (K.I.).

Energy spectrum of extragalactic gamma-ray sources

Science.gov (United States)

Protheroe, R. J.

1985-01-01

The result of Monte Carlo electron photon cascade calculations for propagation of gamma rays through regions of extragalactic space containing no magnetic field are given. These calculations then provide upper limits to the expected flux from extragalactic sources. Since gamma rays in the 10 to the 14th power eV to 10 to the 17th power eV energy range are of interest, interactions of electrons and photons with the 3 K microwave background radiation are considered. To obtain an upper limit to the expected gamma ray flux from sources, the intergalactic field is assumed to be so low that it can be ignored. Interactions with photons of the near-infrared background radiation are not considered here although these will have important implications for gamma rays below 10 to the 14th power eV if the near infrared background radiation is universal. Interaction lengths of electrons and photons in the microwave background radiation at a temperature of 2.96 K were calculated and are given.

Large dimuon asymmetry in B{sub s}-B-bar{sub s} mixing from unparticle induced {Gamma}{sub s}{sup 12}

Energy Technology Data Exchange (ETDEWEB)

Ren Bo [INPAC, Department of Physics, Shanghai Jiao Tong University, Shanghai (China); He Xiaogang, E-mail: hexg@phys.ntu.edu.t [INPAC, Department of Physics, Shanghai Jiao Tong University, Shanghai (China); Department of Physics and Center for Theoretical Sciences, National Taiwan University, Taipei, Taiwan (China); Xie Peichu [INPAC, Department of Physics, Shanghai Jiao Tong University, Shanghai (China)

2011-04-11

Exchange of unparticle stuff of dimension d{sub U} with FCNC interaction can induce M{sup 12,u} and {Gamma}{sup 12,u} causing meson and antimeson mixing with the relation {Gamma}{sup 12,u}/M{sup 12,u}=2tan({pi}d{sub U}). We show that this type of unparticle contribution can provide the much needed large {Gamma}{sub s}{sup 12} to explain the recently observed anomalously large dimuon asymmetry in B{sub s}-B-bar{sub s} system reported by D0 Collaboration. The same interaction can also accommodate large mixing induced CP violation in B{sub s{yields}}J/{psi}{phi} indicated by CDF and D0 data. Experimental data can provide constraints on the unparticle dimension and scale.

Protective Role of Emodin in Reducing The Gamma Rays Induced Hazardous Effects On The Tongue of Diabetic or Normoglycaemic Mice

International Nuclear Information System (INIS)

Haggag, M.G.; Kazem, H.H.

2013-01-01

Ionizing radiation leads to damage at various cellular and sub-cellular levels and can be prevented by radio protectors. There is a need for natural prospective radio protectors that protect normal tissues from ionizing radiation in patients receiving high doses of radiation for treating malignant neoplasms. The study aimed to evaluate the potential protective role of emodin in reducing the severity of gamma rays-induced hazardous damage in the tongue of normoglycaemic and diabetic mice. Sixty-four male mice were randomly divided into 8 experimental groups: control group received vehicle, emodin group received daily emodin dose of 4g/kg orally for a week, diabetes mellitus (DM) group in which DM was induced by streptozotocin (STZ) treatment, emodin + DM received emodin for a week + STZ treatment, irradiated group submitted to 4 Gy of gamma rays and received vehicle for a week, gamma rays + DM group received gamma rays + STZ treatment, gamma rays + emodin group received gamma rays + emodin for a week, and gamma rays + DM + emodin group received gamma rays + STZ treatment + emodin for a week. Tongue and serum of mice were biochemically examined for screening gamma radiation and diabetic damages and the efficacy of emodin in ameliorating these damaging effects. The levels of cellular thiols such as reduced glutathione (GSH), oxidized glutathione (GSSG), total thiols (TT) and lipid peroxidation products; malondialdehyde (MDA) and conjugated dienes (CD), were assessed in tongue tissues. Tongue antioxidant enzymes; gamma glutamyl transferase (GGT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glucose-6-phosphatase (G-6-P), were measured and serum glucose level was estimated. The results revealed alterations of the levels of cellular thiols and antioxidant enzymes in tongue and the level of glucose in serum of gamma irradiated diabetic mice were ameliorated in mice groups received emodin treatment. The results suggest that emodin treatment (4 g

Action of the chlorophyllin on the genetic damage induced by gamma radiation in germinal cells of Drosophila Melanogaster

International Nuclear Information System (INIS)

Cruces, M.P.; Pimentel, A.E.; Moreno, A.; Moreno, R.

2003-01-01

The obtained results using somatic cells, they have evidenced that the chlorophyllin (CHLN) it can act inhibiting or increasing the damage caused by different mutagens. The objective of this investigation is to evaluate the effect of the CHLN on the damage induced by gamma radiation in germinal cells of Drosophila. Two tests were used, the lost of the X chromosome and the conventional test of lethal recessive bound to the sex (LRLS); both with a system of litters. The obtained results in both essays, indicated that the CHLN doesn't reduce the damage induced by the gamma radiation in none of the cellular monitored states. (Author)

Experiment on direct nn scattering - The radiation-induced outgassing complication

Energy Technology Data Exchange (ETDEWEB)

Stephenson, S.L., E-mail: sstephen@gettysburg.edu [Gettysburg College, Gettysburg, PA 17325 (United States); Crawford, B.E. [Gettysburg College, Gettysburg, PA 17325 (United States); Furman, W.I.; Lychagin, E.V.; Muzichka, A.Yu.; Nekhaev, G.V.; Sharapov, E.I.; Shvetsov, V.N.; Strelkov, A.V. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Levakov, B.G.; Lyzhin, A.E.; Chernukhin, Yu.I. [Russian Federal Nuclear Center - All Russian Research Institute of Technical Physics, P.O. Box 245, 456770 Snezhinsk (Russian Federation); Howell, C.R. [Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Mitchell, G.E. [North Carolina State University, Raleigh, NC 27695-8202 (United States); Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Tornow, W. [Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Showalter-Bucher, R.A. [Northeastern University, Boston, MA 02115 (United States)

2012-12-01

The first direct neutron-neutron scattering experiment using the YAGUAR pulsed reactor has yielded initial results. They show a unforeseen significant thermal neutron background as a result of radiation-induced desorption within the scattering chamber. Thermal neutrons are mostly scattering not from other neutrons but instead from the desorbed gas molecules. Analysis of the obtained neutron time-of-flight spectra suggests neutron scattering from H{sub 2} molecules. The presented desorption model agrees with our experimental value of the desorption yield {eta}{sub {gamma}}=0.02 molecules/gamma. Possible techniques to reduce the effect of the desorption background are presented.

α-rays induced background in ultra low level counting with Ge spectrometers

International Nuclear Information System (INIS)

Hubert, P.; Dassie, D.; Larrieu, P.; Leccia, F.; Mennrath, P.; Chevallier, J.; Chevallier, A.; Morales, A.; Nunez-Lagoz, R.; Morales, J.; Villar, J.A.

1986-01-01

Background spectra of several spectrometers have been recorded in a deep underground laboratory located in the Frejus tunnel. The results show that an α ray induced background from the 210 Pb decay is observed. A possible explanation could be related to the adsorption of the Rn gas on the surfaces of the Ge crystal and/or other parts during the assembly of the spectrometer. (orig.)

Isozymes variability in rice mutants induced by fast neutrons and gamma rays

International Nuclear Information System (INIS)

Fuentes, J.L.; Alvarez, A.; Gutierrez, L.; Deus, J.E.

2001-01-01

The isozyme variability of a group of rice mutants induced through gamma and fast neutron (14 MeV) irradiation was studied. Polymorphisms were detected using esterase, peroxidase, polyphenol oxidase and alcohol dehydrogenase systems. The mean value of genetic similarity among the different cultivars, which arose from isozymes, was 0.75. The dendrogram was constructed based on genetic similarity matrices, designed with isozyme data using the unweighed pair group method arithmetic average (UPGMA) method. The efficiency of the UPGMA model for the estimation of genetic relationship among cultivars was supported by cophenetic correlation coefficients. Such values indicate that the distortion degree for the estimated similarities was minimal. It was found that both gamma rays and fast neutrons generated a wide range of variability which can be detected by means of isozyme patterns, even in closely related cultivars. (author)

Isozymes variability in rice mutants induced by fast neutrons and gamma rays

Energy Technology Data Exchange (ETDEWEB)

Fuentes, J L; Alvarez, A [Centro de Estudios Aplicados al Desarrollo Nuclear (CEADEN), Miramar, Playa, Havana (Cuba); Gutierrez, L; Deus, J E [Instituto de Investigaciones del Arroz, Bauta, Havana (Cuba)

2001-05-01

The isozyme variability of a group of rice mutants induced through gamma and fast neutron (14 MeV) irradiation was studied. Polymorphisms were detected using esterase, peroxidase, polyphenol oxidase and alcohol dehydrogenase systems. The mean value of genetic similarity among the different cultivars, which arose from isozymes, was 0.75. The dendrogram was constructed based on genetic similarity matrices, designed with isozyme data using the unweighed pair group method arithmetic average (UPGMA) method. The efficiency of the UPGMA model for the estimation of genetic relationship among cultivars was supported by cophenetic correlation coefficients. Such values indicate that the distortion degree for the estimated similarities was minimal. It was found that both gamma rays and fast neutrons generated a wide range of variability which can be detected by means of isozyme patterns, even in closely related cultivars. (author)

Feasibility study of {sup 235}U and {sup 239}Pu characterization in radioactive waste drums using neutron-induced fission delayed gamma rays

Energy Technology Data Exchange (ETDEWEB)

Nicol, T. [CEA, DEN, Cadarache, Nuclear Measurement Laboratory, F-13108 Saint-Paul-lez-Durance (France); FZJ, Institute of Energy and Climate Research – Nuclear Waste Management and Reactor Safety, Wilhelm-Johnen-Straße, d-52425 Jülich (Germany); Pérot, B., E-mail: bertrand.perot@cea.fr [CEA, DEN, Cadarache, Nuclear Measurement Laboratory, F-13108 Saint-Paul-lez-Durance (France); Carasco, C. [CEA, DEN, Cadarache, Nuclear Measurement Laboratory, F-13108 Saint-Paul-lez-Durance (France); Brackx, E. [CEA, DEN, Marcoule, Metallography and Chemical Analysis Laboratory, F-30207 Bagnols-sur-Cèze (France); Mariani, A.; Passard, C. [CEA, DEN, Cadarache, Nuclear Measurement Laboratory, F-13108 Saint-Paul-lez-Durance (France); Mauerhofer, E. [FZJ, Institute of Energy and Climate Research – Nuclear Waste Management and Reactor Safety, Wilhelm-Johnen-Straße, d-52425 Jülich (Germany); Collot, J. [Laboratoire de Physique Subatomique et de Cosmologie, Université Grenoble Alpes, CNRS/IN2P3 Grenoble (France)

2016-10-01

This paper reports a feasibility study of {sup 235}U and {sup 239}Pu characterization in 225 L bituminized waste drums or 200 L concrete waste drums, by detecting delayed fission gamma rays between the pulses of a deuterium-tritium neutron generator. The delayed gamma yields were first measured with bare samples of {sup 235}U and {sup 239}Pu in REGAIN, a facility dedicated to the assay of 118 L waste drums by Prompt Gamma Neutron Activation Analysis (PGNAA) at CEA Cadarache, France. Detectability in the waste drums is then assessed using the MCNPX model of MEDINA (Multi Element Detection based on Instrumental Neutron Activation), another PGNAA cell dedicated to 200 L drums at FZJ, Germany. For the bituminized waste drum, performances are severely hampered by the high gamma background due to {sup 137}Cs, which requires the use of collimator and shield to avoid electronics saturation, these elements being very penalizing for the detection of the weak delayed gamma signal. However, for lower activity concrete drums, detection limits range from 10 to 290 g of {sup 235}U or {sup 239}Pu, depending on the delayed gamma rays of interest. These detection limits have been determined by using MCNPX to calculate the delayed gamma useful signal, and by measuring the experimental gamma background in MEDINA with a 200 L concrete drum mock-up. The performances could be significantly improved by using a higher interrogating neutron emission and an optimized experimental setup, which would allow characterizing nuclear materials in a wide range of low and medium activity waste packages.

Gamma ray induced somatic mutations in rose

International Nuclear Information System (INIS)

Datta, S.K.

1989-01-01

Budwood of 32 rose cultivars (Rosa spp.) was exposed to 3-4 krad of gamma rays and eyes were grafted on Rosa indica var. odorata root stock. Radiosensitivity with respect to sprouting, survival and plant height, and mutation frequency varied with the cultivar and dose of gamma rays. Somatic mutations in flower colour/shape were detected as chimera in 21 cultivars. The size of the mutant sector varied from a narrow streak on a petal to a whole flower and from a portion of a branch to an entire branch. 14 mutants were detected in M 1 V 1 , four in M 1 V 2 and three in M 1 V 3 . Maximum number of mutations was detected following 3 krad treatment. Eyes from mutant branches were grafted again on root stock and non-chimeric mutants were aimed at by vegetative propagation. Mutants from 11 cultivars only could be isolated in pure form. Isolation of non-chimeric mutants sometimes is difficult due to weak growth of a mutant branch. In such a case, all normal looking branches are removed to force a better growth of the mutant branch. It is advisable to maintain irradiated plants at least for four years with drastic pruning in each year. Nine mutants viz. 'Sharada', 'Sukumari', 'Tangerine Contempo', 'Yellow Contempo', 'Pink Contempo', 'Striped Contempo', 'Twinkle', 'Curio' and 'Light Pink Prize' have already been released as new cultivars for commercialization [ref. MBNL No. 23 and 31] and others are being multiplied and assessed. The mutation spectrum appears to be wider for the cultivars 'Contempo' and 'Imperator'. Pigment composition of the original variety is relevant for the kind of flower colour mutations that can be induced

Two-quantum Doppler-free induced gamma emission

International Nuclear Information System (INIS)

Zadernovsky, A.A.

1999-01-01

Reported here is a theoretical study of an alternative way to remove the pernicious influence of chaotic motion of free nuclei by means of external ignition of two-quantum IGE process in counter-propagating intense photon beams. The performed analysis reveals the main advantages and drawbacks of this method. The following conclusions are underlined: 1. in contrast to single-quantum emission in an ensemble of nuclei with Doppler-broadened gain line, this method involves all nuclei regardless of there individual velocities; 2. a specific dynamic distributed feedback is in this case established in absence of any reflecting structures; 3. because of non-linearity of the feedback, with a coefficient proportional to the photon flux density of the igniting beam, the excitation of nuclei is released in an avalanche-like manner, which result in emission of a giant pulse of gamma quanta; 4. at present, the implementation of such a process is impeded by the absence of a source of igniting gamma quanta, with the sufficient photon flux density. Therefore the advantage of the propose technique may manifests themselves only in designing a final stage of a source of gamma quanta (e.g., in X-ray or gamma-ray laser, relativistic undulator, free electron laser, etc.) for production of short giant pulse of coherent gamma photons. (author)

Gamma-sterilization-induced radicals in biodegradable drug delivery systems

International Nuclear Information System (INIS)

Maeder, K.; Swartz, H.M.; Domb, A.

1996-01-01

Electron paramagnetic resonance (EPR) spectroscopy (1.2 and 9.25 GHz, 25 o C) was used to characterize free radicals in gamma-ray sterilized biodegradable polymers of the type which are in clinical use. Free radicals were detected in all irradiated polymer samples. The temperature of irradiation (25 o vs dry ice temperature) had only a minor influence on the yield of radicals and the shape of the EPR spectra. In contrast, the composition of the polymers and the drugs incorporated in them did strongly influence the amount of radiation-induced free radicals and their reactivity. In general, polymers with high melting points and crystallinity had the highest yields of radicals observable at room temperature. We were able to use the free radicals induced by the usual sterilization procedures to follow the penetration of water and the degradation of the polymers in vitro and in vivo. The ability of in vivo EPR to follow drug delivery noninvasively and continuously in vivo, using the free radicals induced in the usual sterilization process indicates that this approach could be applied immediately for the characterization of these drug delivery systems in experimental animals and in the near future should be able to be used in human subjects. (author)

A new recoil filter for {gamma}-detector arrays

Energy Technology Data Exchange (ETDEWEB)

Heese, J; Lahmer, W; Maier, K H [Hahn-Meitner-Institut Berlin GmbH (Germany); Janicki, M; Meczynski, W; Styczen, J [Institute of Nuclear Physics, Cracow (Poland)

1992-08-01

A considerable improvement of gamma spectra recorded in heavy ion induced fusion evaporation residues can be achieved when gamma rays are detected in coincidence with the recoiling evaporations residues. This coincidence suppresses gamma rays from fission processes, Coulombic excitation, and reactions with target contaminations, and therefore cleans gamma spectra and improves the peak to background ratio. A sturdy detector for evaporation residues has been designed as an additional detector for the OSIRIS spectrometer. The recoil filter consists of two rings of six and twelve detector elements. In each detector element, nuclei hitting a thin Mylar foil produce secondary electrons, which are electrostatically accelerated and focussed onto a thin plastic scintillator. Recoiling evaporation residues are discriminated from other reaction products and scattered beam by the pulse height of the scintillation signal and time of flight. The detector signal is fast enough to allow the detection of an evaporation residue even if the scattered beam hits the detector first. In-beam experiment were performed with the reactions {sup 40}Ar+{sup 124}Sn, {sup 40}Ar+{sup 152}Sm at 185 MeV beam energy, and {sup 36}Ar+{sup 154,156}Gd at 175 MeV. In the latter two cases, fission amount to 50-75% of the total fusion cross section. 10 refs., 4 figs.

Evaluation of Some Chemical Characteristics of barley Mutants induced by Gamma Irradiation

International Nuclear Information System (INIS)

Abdeldaiem, M.H.; Ali, H.G.M.

2011-01-01

This study aims to evaluate the antioxidant activity of acetonic extract from some barley mutations (P1, P2 and P3 varieties) induced by gamma irradiation as compared with local barley variety (Hordeum vulgare L.) as control. Barley samples were obtained from Plant Breeding Unit, Plant Research Department, Nuclear Research Centre, Atomic Energy Authority, Egypt. The measurements of the antioxidant activity using a radical scavenging capacity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ?-carotene bleaching assay were assessed in the barley acetonic extract. Furthermore, amino acids composition of barley mutant samples was determined. The results indicated that the acetonic extract of barley varieties under investigation possess marked antioxidant and anti radical capacities. The data showed that the acetonic extract of barley mutant P1 possessed the higher antioxidant activity as compared with the antioxidant activities of acetonic extract from control and other barley mutant samples. Meanwhile, the flour of barley mutations under investigation contained trace elements of iron, copper and manganese. GC and mass analyses were used to identify the active compound of extract of control and mutant barley samples. The results illustrated that the main components of the control sample of barely extract was pentane, 3 methyl (47.73%) while gamma irradiation caused noticeable change in the relative percentage of some components of acetonic extract from barley mutant samples. Moreover, the results presented that changes were disappeared, and some compounds of the acetonic extract from mutant barley samples were appeared. Furthermore, the results exhibited that barley flour supplemented with wheat flour at 30% level produced acceptable cookies. Accordingly, the phenolic constituents of barley acetonic extract induced by gamma irradiation, especially samples of P1 mutant, may have a future role as ingredients in the development of functional foods.

Diffuse Cosmic Infrared Background Radiation

Science.gov (United States)

Dwek, Eli

2002-01-01

The diffuse cosmic infrared background (CIB) consists of the cumulative radiant energy released in the processes of structure formation that have occurred since the decoupling of matter and radiation following the Big Bang. In this lecture I will review the observational data that provided the first detections and limits on the CIB, and the theoretical studies explaining the origin of this background. Finally, I will also discuss the relevance of this background to the universe as seen in high energy gamma-rays.

Laser Compton Scattering Gamma Ray Induced Photo-Trasmutation

CERN Document Server

Li, Dazhi

2004-01-01

High brightness beams of gamma rays produced with laser Compton scattering have the potential to realize photo-transmutation through (γ,n) reaction, implying an efficient method to dispose long-lived fission products. Preliminary investigations have been carried out in understanding the feasibility of development of a transmutation facility to repose nuclear waste. A laser Compton scattering experimental setup based on a storage ring started to generate gamma-ray beams for studying the coupling of gamma photons and nuclear giant resonance. This paper demonstrates the dependency of nuclear transmutation efficiency on target dimensions and gamma ray features. 197Au sample was adopted in our experiment, and experimental results correspond to the theoretical estimations.

Protective Role of Spirulina on Gamma Rays Induced Haematological and Biochemical Disorders in Mice

International Nuclear Information System (INIS)

Ibrahim, R.M.; Kamal El-Dein, E.M.

2014-01-01

The present study reports the haematological and biochemical protective effect of Salipriina on Swiss albino mice exposed to gamma radiation. Swiss albino mice (8 weeks old) were administered intraperitoneally Sanepil (800 mg/kg b.wt.) prior to whole body gamma-irradiation (7.5 Gy). Radiation exposure resulted in a significant decline in different bone marrow cells (pro-and normoblasts) and blood constituents (erythrocytes, leukocytes, differential leukocyte count, haematocrit,haemoglobin and erythrocyte sedimentation rate). Pro- and normoblasts, erythrocytes, leukocytes, haematocrit and haemoglobin values showed a significant (p<0.05) decline during the first 3 days, followed by a gradual recovery starting from day 7, but normal values were not recorded until 14 days post-exposure. Treatment of mice with Spirulina also caused a significant decrease in malondialdehyde (MDA) formation in the liver, suggesting its role in protection against radiation induced membrane and cellular damage. Similarly, pretreatment of mice with Spirulina caused a significant increase in serum glutathione (GSH) level in comparison with that of irradiated animals. Results suggest that Spirulina modulate the radiation induced hematological and biochemical alterations in Swiss albino mice

Investigating and comparing uranium and gamma radiation induced effects on photosynthetic parameters for Arabidopsis thaliana

Energy Technology Data Exchange (ETDEWEB)

Vanhoudt, Nathalie; Horemans, Nele; Saenen, Eline; Biermans, Geert; Nauts, Robin; Wannijn, Jean; Van Hees, May; Vandenhove, Hildegarde [Belgian Nuclear Research Centre (SCK.CEN), Biosphere Impact Studies, 2400, Mol (Belgium)

2014-07-01

As the environment is inevitably exposed to radionuclides and ionizing radiation from natural and anthropogenic sources, it is important to study the effects induced by these stressors on plants. In addition, it is already known that photosynthesis can be affected under various metal exposure situations. The objective of this research is to compare uranium induced effects with gamma radiation induced effects on photosynthetic parameters in Arabidopsis thaliana. First, 18-day-old seedlings were exposed to 50 μM uranium during 4 days. Second, 14-day-old seedlings were exposed to gamma radiation for 7 days to a total dose of 6.7 Gy. By using chlorophyll fluorescence measurements, the photosynthetic performance was assessed. Based on the data obtained during the measurement of induction curves, parameters providing information on the photosynthetic efficiency and heat dissipation can be calculated. For uranium exposed leaves, it was observed that the potential photosynthetic efficiency (measured as Fv/Fm) remained maximal while the effective efficiency of photosystem II (φPSII), which is a measure for the proportion of light absorbed by PSII used in photochemistry, even increased. The increase of φPSII could be related to a decrease in non-photochemical quenching (NPQ), which reflects the protective mechanism against excess light intensity by converting energy into heat, but no alterations in non-regulated energy dissipation (NO). A high NO value would indicate the inefficiency of photochemistry and heat conversion and the plant's inability to regulate the radiation energy. In plants exposed to uranium, NO levels were similar to the control. Under gamma irradiation, the capacity of PSII remained intact and plants started optimizing their photosynthetic process by increasing φPSII and decreasing NPQ. When comparing the NPQ kinetic responses of gamma radiation and uranium exposure, a remarkable difference can be highlighted. While gamma radiation exposure

Induced mutation in dwarf growth habits of apple trees by gamma rays and its evaluation in practical uses

International Nuclear Information System (INIS)

Ikeda, Fukio

1979-01-01

A series of mutation breeding experiments on apple has been made. The dwarf type mutants having dwarfing rootstock effects on top varieties were developed in the gamma field. In this paper, the induction efficiency that the desirable spur type mutants for top, and the effective dwarf type mutants for rootstocks are produced in a gamma field in comparison with acute irradiation, and some evaluation of the induced mutants for practical purposes are described. A large number of the spur type mutants of apple trees having dwarf growth habit and a desirable tree form for high density planting have been induced by chronic or acute irradiation of gamma-ray since 1962. The mutation with dwarf growth habit including spur types was detected in the grafts on the clonal rootstocks of Marubakaido Malus prunifolia. No useful mutation toward the trees with dwarf growth habit and favorable fruit quality was recognized in the mutants derived from acute irradiation. Chronic treatment has been conducted in the uninjurious area in the gamma field on settled trees. High mutability in the dwarf growth of aged resting buds of settled trees was examined by twice-repeated cutting back treatments. In conclusion, for the induction of useful mutants or effective dwarfing mutants as clonal rootstocks, the artificial mutation breeding with gamma-ray should be conducted under chronic conditions and by planned cutting back treatments, in order to avoid various chromosomal aberrations and intrasomatic selection. (Kato, T.)

Possible Protective Effect of Aqueous Extract of Moringa oleifera Lam. on Gamma Radiation Induced-Oxidative Stress in Rats

International Nuclear Information System (INIS)

Abd El-Azime, A.Sh.; Kamal El-Dein, E.M.

2014-01-01

Medicinal herbs are used in indigenous system of medicine for various diseases. Moringa oleifera (M. oleifera) has a high medicinal value which has been recognized. The present study was designed to evaluate the protective effect of aqueous extract of M. oleifera leaves against whole body gamma radiation-induced toxicity in rats. Rats received orally by gavage the aqueous extract of M. oleifera leaves 300 mg/Kg body weight/day for 40 days and rats subjected to whole body gamma-irradiation at a dose of 5 Gy delivered as single exposure dose at day 35 of M. oleifera treatment rats and sacrificed at 5th day after irradiation. The results obtained showed that exposure to gamma radiation provoked a significant increase in serum gamma-glutamyl transpeptidase (γ-GT), alanine transaminase (ALT), aspartate transaminase (AST), and alkaline phosphatase (ALP), glucose, total cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol (LDL-C) and very low density lipoprotein cholesterol (vLDL-C) level. While high density lipoprotein cholesterol (HDL-C) and insulin level showed a significant decrease. Moreover a significant decrease of glutathione (GSH) content, superoxide dismutase (SOD) and catalase (CAT) activities associated to a significant increase of thiobarbituric acid reactive substances (TBARS) were recorded in blood and liver of rats. Treatment with M. oleifera significantly reduced the radiation-induced serum and liver biochemical disorders which was associated with a significant amelioration in antioxidant status in both liver and serum. The results indicated that M. oleifera might protect from radiation induced damage due to its ability to scavenge free radicals

Measurement of concentrations of {gamma}-ray emitters induced in the concrete shield of the JAERI electron linac facility

Energy Technology Data Exchange (ETDEWEB)

Endo, Akira; Kawasaki, Katsuya; Kikuchi, Masamitsu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Harada, Yasunori

1997-07-01

Measurement has been made to study distributions of {gamma}-ray emitters induced in the concrete shield of the JAERI electron linac facility. Core boring was carried out at seven positions to take samples from the concrete shield, and {gamma}-ray counting rates and {gamma}-ray spectra of these samples were measured with a NaI(Tl) detector and a Ge semiconductor detector, respectively. The following radionuclides were detected in the concrete samples: {sup 60}Co, {sup 134}Cs, {sup 152}Eu and {sup 154}Eu generated through thermal neutron capture reaction, and {sup 22}Na and {sup 54}Mn generated through nuclear reactions by bremsstrahlung and fast neutrons. The relation between the distributions of {gamma}-ray emitters, as a function of the depth of concrete, and the positions of core boring is discussed. (author)

Extragalactic background light from hierarchical galaxy formation. Gamma-ray attenuation up to the epoch of cosmic reionization and the first stars

Energy Technology Data Exchange (ETDEWEB)

Inoue, Yoshiyuki [Stanford Univ., CA (United States). Kavli Inst. for Particle Astrophysics and Cosmology; Inoue, Susumu [Max Planck Inst. for Nuclear Physics, Heidelberg (Germany); Univ. of Tokyo (Japan). Inst. for Cosmic Ray Research; Kobayashi, Masakazu A. R. [Ehime Univ., Matsuyama (Japan). Research Center for Space and Cosmic Evolution; Makiya, Ryu [Kyoto Univ. (Japan). Dept. of Astronomy; Niino, Yuu [National Astronomical Observatory of Japan, Mitaka (Tokyo). Optical and Infrared Astronomy Division; Totani, Tomonori [Kyoto Univ. (Japan). Dept. of Astronomy

2013-04-26

Here, we present a new model of the extragalactic background light (EBL) and corresponding γγ opacity for intergalactic gamma-ray absorption from z = 0 up to z = 10, based on a semi-analytical model of hierarchical galaxy formation that reproduces key observed properties of galaxies at various redshifts. Including the potential contribution from Population III stars and following the cosmic reionization history in a simplified way, the model is also broadly consistent with available data concerning reionization, particularly the Thomson scattering optical depth constraints from Wilkinson Microwave Anisotropy Probe (WMAP). In comparison with previous EBL studies up to z ~ 3-5, our predicted γγ opacity is in general agreement for observed gamma-ray energy below 400/(1 + z) GeV, whereas it is a factor of ~2 lower above this energy because of a correspondingly lower cosmic star formation rate, even though the observed ultraviolet (UV) luminosity is well reproduced by virtue of our improved treatment of dust obscuration and direct estimation of star formation rate. Moreover, the horizon energy at which the gamma-ray opacity is unity does not evolve strongly beyond z ~ 4 and approaches ~20 GeV. The contribution of Population III stars is a minor fraction of the EBL at z = 0, and is also difficult to distinguish through gamma-ray absorption in high-z objects, even at the highest levels allowed by the WMAP constraints. Nevertheless, the attenuation due to Population II stars should be observable in high-z gamma-ray sources by telescopes such as Fermi or the Cherenkov Telescope Array and provide a valuable probe of the evolving EBL in the rest-frame UV. Our detailed results of our model are publicly available in numerical form at http://www.slac.stanford.edu/~yinoue/Download.html.

On Einsteinization of background curved space in the induced quantum gravity

International Nuclear Information System (INIS)

Novozhilov, Y.V.; Vassilevich, D.V.

1989-09-01

It is shown within the induced quantum gravity approach that approximate invariance of the vacuum (up to topological terms) under rescaling of background tetrads requires that these tetrads should satisfy the Einstein equation with the Newton and cosmological constants defined by low energy parameters. (author). 7 refs

Neutron-induced Backgrounds in 134Xe for Large-Scale Neutrinoless Double-Beta Decay Experiments

Science.gov (United States)

Moriguchi, Nina; Kidd, Mary; Tornow, Werner

2016-09-01

136Xe is used in large neutrinoless double-beta (0 νββ) decay experiments, such as KamLAND- Zen and EXO 200. Though highly purified, 136Xe still contains a significant amount of 134Xe. Recently, a new nuclear energy level was found in 134Xe. If 134Xe decays from this proposed excited state, it will emit a 2485.7 keV gamma ray. Because this energy lies near the region of interest of 136Xe νββ decay experiments (Q value 2457.8 keV), it could make a significant contribution to the background. A purified gaseous sample of 134Xe will be irradiated with neutrons of an incident energy of 4.0 MeV at Triangle Universities Nuclear Laboratory and monitored with high-purity germanium detectors. The spectra obtained from these detectors will be analyzed for the presence of the 2581 keV gamma ray. We will report on the status of this experiment. Future plans include expanding this measurement to higher initial neutron energies. Tennesse Tech University CISE Grant program.

Measurement of 235U content and flow of UF6 using delayed neutrons or gamma rays following induced fission

International Nuclear Information System (INIS)

Stromswold, D.C.; Peurrung, A.J.; Reeder, P.L.; Perkins, R.W.

1996-06-01

Feasibility experiments conducted at Pacific Northwest National Laboratory demonstrate that either delayed neutrons or energetic gamma rays from short-lived fission products can be used to monitor the blending of UF 6 gas streams. A 252 Cf neutron source was used to induce 235 U fission in a sample, and delayed neutrons and gamma rays were measured after the sample moved open-quotes down-stream.close quotes The experiments used a UO 2 powder that was transported down the pipe to simulate the flowing UF 6 gas. Computer modeling and analytic calculation extended the test results to a flowing UF 6 gas system. Neutron or gamma-ray measurements made at two downstream positions can be used to indicate both the 235 U content and UF 6 flow rate. Both the neutron and gamma-ray techniques have the benefits of simplicity and long-term reliability, combined with adequate sensitivity for low-intrusion monitoring of the blending process. Alternatively, measuring the neutron emission rate from (a, n) reactions in the UF 6 provides an approximate measure of the 235 U content without using a neutron source to induce fission

DECIPHERING CONTRIBUTIONS TO THE EXTRAGALACTIC GAMMA-RAY BACKGROUND FROM 2 GeV TO 2 TeV

Energy Technology Data Exchange (ETDEWEB)

Lisanti, Mariangela; Mishra-Sharma, Siddharth [Department of Physics, Princeton University, Princeton, NJ 08544 (United States); Necib, Lina; Safdi, Benjamin R. [Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

2016-12-01

Astrophysical sources outside the Milky Way, such as active galactic nuclei and star-forming galaxies, leave their imprint on the gamma-ray sky as nearly isotropic emission referred to as the extragalactic gamma-ray background (EGB). While the brightest of these sources may be individually resolved, their fainter counterparts contribute diffusely. In this work, we use a recently developed analysis method, called the Non-Poissonian Template Fit, on up to 93 months of publicly available data from the Fermi Large Area Telescope to determine the properties of the point sources (PSs) that comprise the EGB. This analysis takes advantage of photon-count statistics to probe the aggregate properties of these source populations below the sensitivity threshold of published catalogs. We measure the source-count distributions and PS intensities, as a function of energy, from ∼2 GeV to 2 TeV. We find that the EGB is dominated by PSs, likely blazars, in all seven energy sub-bins considered. These results have implications for the interpretation of IceCube’s PeV neutrinos, which may originate from sources that contribute to the non-blazar component of the EGB. Additionally, we comment on implications for future TeV observatories such as the Cherenkov Telescope Array. We provide sky maps showing locations most likely to contain these new sources at both low (≲50 GeV) and high (≳50 GeV) energies for use in future observations and cross-correlation studies.

DECIPHERING CONTRIBUTIONS TO THE EXTRAGALACTIC GAMMA-RAY BACKGROUND FROM 2 GeV TO 2 TeV

International Nuclear Information System (INIS)

Lisanti, Mariangela; Mishra-Sharma, Siddharth; Necib, Lina; Safdi, Benjamin R.

2016-01-01

Astrophysical sources outside the Milky Way, such as active galactic nuclei and star-forming galaxies, leave their imprint on the gamma-ray sky as nearly isotropic emission referred to as the extragalactic gamma-ray background (EGB). While the brightest of these sources may be individually resolved, their fainter counterparts contribute diffusely. In this work, we use a recently developed analysis method, called the Non-Poissonian Template Fit, on up to 93 months of publicly available data from the Fermi Large Area Telescope to determine the properties of the point sources (PSs) that comprise the EGB. This analysis takes advantage of photon-count statistics to probe the aggregate properties of these source populations below the sensitivity threshold of published catalogs. We measure the source-count distributions and PS intensities, as a function of energy, from ∼2 GeV to 2 TeV. We find that the EGB is dominated by PSs, likely blazars, in all seven energy sub-bins considered. These results have implications for the interpretation of IceCube’s PeV neutrinos, which may originate from sources that contribute to the non-blazar component of the EGB. Additionally, we comment on implications for future TeV observatories such as the Cherenkov Telescope Array. We provide sky maps showing locations most likely to contain these new sources at both low (≲50 GeV) and high (≳50 GeV) energies for use in future observations and cross-correlation studies.

Study of radionuclide and element characterization of Angola marine sediment using low background gamma spectrometry and instrumental neutron activation analysis techniques

International Nuclear Information System (INIS)

Teixeira, M.C.P.; Vuong Huu Tan; Truong Y; Ho Manh Dung; Le Nhu Sieu; Cao Dong Vu; Nguyen Thanh Binh

2007-01-01

The concentrations of radionuclides and chemical elements in Angola marine sediment samples were determined by using low background gamma (LBG) spectrometry and instrumental neutron activation analysis (INAA). The combination of radionuclide and elemental concentration values yielded synergy in the validation of analytical data and identification of sediment sources modeled by multivariate factor analysis. Varimax rotation factor analysis based on the elemental concentrations revealed five sources contributed to the sediment composition, i.e. crustal, sea-salt, industrial, coal-related and Se-related sources. (author)

Measurements of prompt gamma-rays from fast-neutron induced fission with the LICORNE directional neutron source

CERN Document Server

Wilson, J N; Halipre, P; Oberstedt, S; Oberstedt, A

2014-01-01

At the IPN Orsay we have developed a unique, directional, fast neutron source called LICORNE, intended initially to facilitate prompt fission gamma measurements. The ability of the IPN Orsay tandem accelerator to produce intense beams of $^7$Li is exploited to produce quasi-monoenergetic neutrons between 0.5 - 4 MeV using the p($^7$Li,$^7$Be)n inverse reaction. The available fluxes of up to 7 × 10$^7$ neutrons/second/steradian for the thickest hydrogen-rich targets are comparable to similar installations, but with two added advantages: (i) The kinematic focusing produces a natural neutron beam collimation which allows placement of gamma detectors adjacent to the irradiated sample unimpeded by source neutrons. (ii) The background of scattered neutrons in the experimental hall is drastically reduced. The dedicated neutron converter was commissioned in June 2013. Some preliminary results from the first experiment using the LICORNE neutron source at the IPN Orsay are presented. Prompt fission gamma rays from fas...

DNA polymerase gamma inhibition by vitamin K3 induces mitochondria-mediated cytotoxicity in human cancer cells.

Science.gov (United States)

Sasaki, Ryohei; Suzuki, Yoko; Yonezawa, Yuko; Ota, Yosuke; Okamoto, Yoshiaki; Demizu, Yusuke; Huang, Peng; Yoshida, Hiromi; Sugimura, Kazuro; Mizushina, Yoshiyuki

2008-05-01

Among the vitamin K (VK) compounds, VK3 exhibits distinct cytotoxic activity in cancer cells and is thought to affect redox cycling; however, the underlying mechanisms remain unclear. Here we demonstrate that VK3 selectively inhibits DNA polymerase (pol) gamma, the key enzyme responsible for mitochondrial DNA replication and repair. VK3 at 30 microM inhibited pol gamma by more than 80%, caused impairment of mitochondrial DNA replication and repair, and induced a significant increase in reactive oxygen species (ROS), leading to apoptosis. At a lower concentration (3 microM), VK3 did not cause a significant increase in ROS, but was able to effectively inhibit cell proliferation, which could be reversed by supplementing glycolytic substrates. The cytotoxic action of VK3 was independent of p53 tumor suppressor gene status. Interestingly, VK3 only inhibited pol gamma but did not affect other pol including human pol alpha, pol beta, pol delta, and pol epsilon. VK1 and VK2 exhibited no inhibitory effect on any of the pol tested. These data together suggest that the inhibition of pol gamma by VK3 is relatively specific, and that this compound seems to exert its anticancer activity by two possible mechanisms in a concentration-dependent manner: (1) induction of ROS-mediated cell death at high concentrations; and (2) inhibition of cell proliferation at lower concentrations likely through the suppression of mitochondrial respiratory function. These findings may explain various cytotoxic actions induced by VK3, and may pave the way for the further use of VK3.

Background subtraction system for pulsed neutron logging of earth boreholes

International Nuclear Information System (INIS)

Hertzog, R.C.

1983-01-01

The invention provides a method for determining the characteristics of earth formations surrounding a well borehole comprising the steps of: repetitively irradiating the earth formations surrounding the well bore with relatively short duration pulses of high energy neutrons; detecting during each pulse of high energy neutrons, gamma radiation due to the inelastic scattering of neutrons by materials comprising the earth formations surrounding the borehole and providing information representative thereof; detecting immediately following each such pulse of high energy neutrons, background gamma radiation due to thermal neutron capture and providing information representative thereof; and correcting the inelastic gamma representative information to compensate for said background representative information

Radioactivity observed in the sodium iodide gamma-ray spectrometer returned on the Apollo 17 mission

Science.gov (United States)

Dyer, C. S.; Trombka, J. I.; Schmadebeck, R. L.; Eller, E.; Bielefeld, M. J.; Okelley, G. D.; Eldridge, J. S.; Northcutt, K. J.; Metzger, A. E.; Reedy, R. C.

1975-01-01

In order to obtain information on radioactive background induced in the Apollo 15 and 16 gamma-ray spectrometers (7 cm x 7 cm NaI) by particle irradiation during spaceflight, and identical detector was flown and returned to earth on the Apollo 17 mission. The induced radioactivity was monitored both internally and externally from one and a half hours after splashdown. When used in conjunction with a computation scheme for estimating induced activation from calculated trapped proton and cosmic-ray fluences, these results show an important contribution resulting from both thermal and energetic neutrons produced in the heavy spacecraft by cosmic-ray interactions.

Studies of natural and 60Co gamma radio-induced conduction in metaphosphate glasses and silica

International Nuclear Information System (INIS)

Mengual Gil, M.A.

1977-01-01

A study of natural and 60 Co gamma radio-induced conduction in metaphosphate glasses and silica is presented. The experimental study of natural conduction current in metaphosphate glasses in function of temperature enables to observe two different values of the activation energies in the respective temperature ranges T>223K and T [fr

Neutron stimulated emission computed tomography: Background corrections

International Nuclear Information System (INIS)

Floyd, Carey E.; Sharma, Amy C.; Bender, Janelle E.; Kapadia, Anuj J.; Xia, Jessie Q.; Harrawood, Brian P.; Tourassi, Georgia D.; Lo, Joseph Y.; Kiser, Matthew R.; Crowell, Alexander S.; Pedroni, Ronald S.; Macri, Robert A.; Tajima, Shigeyuki; Howell, Calvin R.

2007-01-01

Neutron stimulated emission computed tomography (NSECT) is an imaging technique that provides an in-vivo tomographic spectroscopic image of the distribution of elements in a body. To achieve this, a neutron beam illuminates the body. Nuclei in the body along the path of the beam are stimulated by inelastic scattering of the neutrons in the beam and emit characteristic gamma photons whose unique energy identifies the element. The emitted gammas are collected in a spectrometer and form a projection intensity for each spectral line at the projection orientation of the neutron beam. Rotating and translating either the body or the beam will allow a tomographic projection set to be acquired. Images are reconstructed to represent the spatial distribution of elements in the body. Critical to this process is the appropriate removal of background gamma events from the spectrum. Here we demonstrate the equivalence of two background correction techniques and discuss the appropriate application of each

Gamma-ray emission profile measurements during JET ICRH discharges

Energy Technology Data Exchange (ETDEWEB)

Howarth, P.J.A. [Birmingham Univ. (United Kingdom); Adams, J.M.; Bond, D.S.; Watkins, N. [AEA Technology, Harwell (United Kingdom); Jarvis, O.N.; Marcus, F.B.; Sadler, G.; Belle, P. van [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking

1994-12-31

Ion Cyclotron Resonant Heating (ICRH) that is tuned to minority fuel ions can induce an energy diffusion of the heated species and create high energy tail temperatures of {approx} 1 MeV. The most energetic of these accelerated minority ions can undergo nuclear reactions with impurity Be and C that produces {gamma}-ray emission from the decay of the excited product nuclei. This RF-induced {gamma}-ray emission has been recorded using the JET neutron emission profile diagnostic which is capable of distinguishing neutrons and {gamma}-rays. Appropriate data processing has enabled the RF-induced {gamma}-ray emission signals to be isolated from the {gamma}-ray emission signals associated with neutron interactions in the material surrounding the profile monitor. The 2-d {gamma}-ray emission profiles show that virtually all the radiation originates from the low field side of the RF resonance layer, as expected from RF-induced pitch angle diffusion. The emission profiles indicate the presence of a small population of resonant {sup 3}He ions that possess orbits lying near the passing-trapped boundary. (author) 6 refs., 4 figs.

Properties of light induced EPR signals in enamel and their possible interference with gamma-induced signals

International Nuclear Information System (INIS)

Sholom, S.V.; Chumak, V.V.; Haskell, E.H.; Hayes, R.B.; Kenner, G.H.

1998-01-01

Exposure of tooth enamel to natural and artificial UV light results in stable EPR signals with g-factors of 1.9985, 2.0018, 2.0045, 2.0052 and 2.0110. The first three signals correspond to the parallel and perpendicular components of the radiation induced or dosimetric signal and the native signal reported in dosimetry and dating studies. The latter two signals were found to be sensitive to both gamma-ray and sunlight exposure, however, their responses to light differed from that to radiation, giving rise to the possibility of using them as indicators of the dose-equivalent resulting from light exposure

Deletions induced by gamma rays in the genome of Escherichia coli

International Nuclear Information System (INIS)

Raha, Manidipa; Hutchinson, Franklin

1991-01-01

An Escherichia coli lysogen was constructed with a lambda phage bearing a lacZ gene surrounded by about 100 x 10 3 base-pairs of dispensable DNA. The lacZ mutants induced by gamma rays in this lysogen were more than 10% large deletions, ranging in size from 0.6 x 10 -3 to 70 x 10 3 base-pairs. These deletions were centered, not on lacZ, but on a ColE1 origin of DNA replication located 1.2 x 10 3 bases downstream from lacZ, suggesting that this origin of replication was involved in the process by which deletions were formed. In agreement with this hypothesis, a lysogen of the same phage without the ColE1 origin showed a very much lower percentage of radiation-induced deletions, as did a second lysogen of a lambda phage without any known plasmid origin of replication. Indirect evidence is presented for radiation-induced deletions centered on the lambda origin of DNA replication in a lysogen. (author)

Detector Background Reduction by Passive and Active Shielding

International Nuclear Information System (INIS)

Bikit, I.; Bikit, K.; Forkapic, S.; Mrda, D.; Nikolov, J.; Slivka, J.; Todorovic, N.

2013-01-01

The operational problems of the gamma ray spectrometer shielded passively with 12 cm of lead and actively by five 0.5 m × 0.5 m × 0.05 m plastic veto shields are described. The active shielding effect from both environmental gamma ray, cosmic muons and neutrons was investigated. For anticoincidence gating wide range of scintillator pulses, corresponding to the energy range of 150 keV-75 MeV, were used. With the optimal set up the integral background, for the energy region of 50 - 3000 keV, of 0.31 c/s was achieved. The detector mass related background was 0.345 c/(kg s). The 511 keV annihilation line was reduced by the factor of 7 by the anticoincidence gate. It is shown that the plastic shields increase the neutron capture gamma line intensities due to neutron termalization.(author)

Gamma-Gompertz life expectancy at birth

OpenAIRE

Trifon I. Missov

2013-01-01

BACKGROUND The gamma-Gompertz multiplicative frailty model is the most common parametric modelapplied to human mortality data at adult and old ages. The resulting life expectancy hasbeen calculated so far only numerically. OBJECTIVE Properties of the gamma-Gompertz distribution have not been thoroughly studied. The focusof the paper is to shed light onto its first moment or, demographically speaking, characterizelife expectancy resulting from a gamma-Gompertz force of mortality. The paperprov...

High Energy Neutron Induced Gamma Production

International Nuclear Information System (INIS)

Brown, D.A.; Johnson, M.; Navratil, P.

2007-01-01

N Division has an interest in improving the physics and accuracy of the gamma data it provides to its customers. It was asked to look into major gamma producing reactions for 14 MeV incident neutrons for several low-Z materials and determine whether LLNL's processed data files faithfully represent the current state of experimental and theoretical knowledge for these reactions. To address this, we surveyed the evaluations of the requested materials, made recommendations for the next ENDL release and noted isotopes that will require further experimental study. This process uncovered several major problems in our translation and processing of the ENDF formatted evaluations, most of which have been resolved

Reversal of rocuronium-induced (1.2 mg/kg) profound neuromuscular block by sugammadex: a multicenter, dose-finding and safety study.

NARCIS (Netherlands)

Boer, H.D. de; Driessen, J.J.; Marcus, M.A.; Kerkkamp, H.E.M.; Heeringa, M.; Klimek, M.

2007-01-01

BACKGROUND: Reversal of rocuronium-induced neuromuscular blockade can be accomplished by chemical encapsulation of rocuronium by sugammadex, a modified gamma-cyclodextrin derivative. This study investigated the efficacy and safety of sugammadex in reversing rocuronium-induced profound neuromuscular

Particle-Induced Gamma-ray Emission Spectroscopy Over a Broad Range of Elements

Science.gov (United States)

Olds, Hannah; Wilkinson, John; Tighe, Meghanne; McLallen, Walter; McGuire, Patrick

2017-09-01

Ion beam analysis is a common application of nuclear physics that allows elemental and isotopic information about materials to be determined from accelerated light ion beams One of the best know ion beam analysis techniques is Particle-Induced Gamma-ray Emission (PIGE) spectroscopy, which can be used ex vacuo to identify the elements of interest in almost any solid target. The energies of the gamma-rays emitted by excited nuclei will be unique to each element and depend on its nuclear structure. For the most sensitivity, the accelerated ions should exceed the Coulomb barrier of the target, but many isotopes are known to be accessible to PIGE even below the Coulomb barrier. To explore the sensitivity of PIGE across the periodic table, PIGE measurements were made on elements with Z = 5, 9, 11-15, 17, 19-35, 37, 42, 44-48, 53, 56, 60, 62, 73, and 74 using 3.4 MeV protons. These measurements will be compared with literature values and be used as a basis for comparison with higher-energy proton beams available at the University of Notre Dame's St. Andre accelerator when it comes online this Fall. The beam normalization technique of using atmospheric argon and its 1459 keV gamma-ray to better estimate the integrated beam on target will also be discussed. Funded by the NSF REU program and the University of Notre Dame.

Gamma rays induced variability in mature embryos of avocado (Persea americana Mill)

International Nuclear Information System (INIS)

Fuentes, J.L.; Ramirez, I. M; Santiago, L.; Valdes, Y.; Guerra, M; Prieto, E.; Rodriguez, N.; Velazquez, B.

2001-01-01

Induced mutation and biotechnology techniques are current approaches used in plant breeding. At present work, the induced mutation and embryo zygotic culture techniques were used in order to characterize the radiosensitivity of avocado commercial varieties, Hass and California. The induced diversity in plant material was also evaluated in morphological seedling descriptors as: height seedling, diameter seedling neck, leaves number, length of principal root and secondary root number. The obtained results showed high susceptibility of both varieties to gamma rays. California was the higher sensitivity variety. Percentage of entire shoot induction showed clear dependence of radiation dose in both varieties. Thus dose range for mutagenesis was determined. In general, variation of morphological seedling descriptors not was clearly agreed to increase of radiation dose. In addition, the results suggested that variation in morphological seedling descriptors also could be depending of genotypes. The useful of mature embryo culture of avocado for improvement of breeding approaches in this crop, was discussed

Development of a cosmic veto gamma-spectrometer

International Nuclear Information System (INIS)

Burnett, J.L.; Davies, A.V.

2012-01-01

Cosmic radiation contributes significantly towards the background radiation measured by a gamma-spectrometer. A novel cosmic veto gamma-spectrometer has been developed that provides a mean background reduction of 54.5%. The system consists of plastic scintillation plates operated in time-stamp mode to detect coincident muon interactions within an HPGe gamma-spectrometer. The instrument is easily configurable and provides improved sensitivity for radionuclides indicative of nuclear weapons tests and reactor incidents, including 140 Ba, 95 Zr, 99 Mo, 141 Ce, 147 Nd, 131 I, 134 Cs and 137 Cs. This has been demonstrated for Comprehensive Nuclear-Test-Ban Treaty applications to obtain the required 140 Ba MDA of 24 mBq within 2 days counting. Analysis of an air filter sample collected during the Fukushima incident indicates improved sensitivity compared to conventional gamma-spectrometers. (author)

Observation of injury effects and apoptosis induced by microwave and gamma ray on lymphocyte in Raji cell

International Nuclear Information System (INIS)

Xia Hongjie; Wang Dewen; Zuo Hongyan; Xu Xinping; Jia Kai; Qiu Bingtao

2011-01-01

To investigate the rule of apoptosis, necrosis and the effects of Raji cell induced by microwave and gamma ray, the Raji cell was exposed to microwave radiation and gamma radiation. Morphological changes were observed by inverted phase contrast microscope before and after radiation. Annexin-V and PI double labelling were used to detect changes of apoptosis and necrosis rate. The results show that the cell shape was changed and the rate of apoptosis and necrosis were increased after exposure to microwave and γ ray. The injury effect of γ+S-HPM compound radiation was more serious than any single radiation on lymphocyte. The major characteristics of injury showed as gamma ray effect. The trends of apoptosis and necrosis keep consistency with the change of the cell morphology after radiation between each observation group. (authors)

Galaxy formation from annihilation-generated supersonic turbulence in the baryon-symmetric big-bang cosmology and the gamma ray background spectrum

Science.gov (United States)

Stecker, F. W.; Puget, J. L.

1972-01-01

Following the big-bang baryon symmetric cosmology of Omnes, the redshift was calculated to be on the order of 500-600. It is show that, at these redshifts, annihilation pressure at the boundaries between regions of matter and antimatter drives large scale supersonic turbulence which can trigger galaxy formation. This picture is consistent with the gamma-ray background observations discussed previously. Gravitational binding of galaxies then occurs at a redshift of about 70, at which time vortical turbulent velocities of about 3 x 10 to the 7th power cm/s lead to angular momenta for galaxies comparable with measured values.

Gamma radiation induced sensitization and photo-transfer in Mg2SiO4:Tb TLD phosphor

International Nuclear Information System (INIS)

Lakshmanan, A.R.; Vohra, K.G.

1979-01-01

Mg 2 SiO 4 :Tb TLD phosphor was found to show enhanced TL sensitivity to both gamma and UV radiations after high pre-gamma exposures (>100 R) and a post-annealing treatment at 300 0 C for 1 h. Maximum sensitization factors of 2.8 and 55 were obtained at the pre-expsoure levels of 5.2x10 1 C/kg and 1.3x10 3 C/kg for gamma and UV test radiations respectively. The near constancy of the intensity of the residual TL (RTL) peak at 500 0 C for the sensitized sample with increasing test-gamma exposures has ruled out the re-trapping model proposed earlier for the gamma radiation induced sensitization in this phosphor. The Tsub(max) for the sensitized phosphor was found to occur at a higher temperature compared to that for the virgin phosphor. The dependence of sensitization on RTL was explained qualitatively on the basis of competition between sensitization traps (having higher energy than the dosimetry traps) and RTL traps while capturing the charge carriers generated during the test-gamma exposure. The sensitization observed in this phosphor to UV test radiation was found to be a consequence of the photo-transfer of charge carriers from deep (RTL) traps to the shallow (dosimetry) traps. The reduction in RTL peak (500 0 C) intensity of the sensitized sample with increasing test-UV exposure has demonstrated the photo-transfer mechanism in this phosphor. The TL response of the virgin Mg 2 SiO 4 :Tb phosphor was found to be supralinear to both gamma and UV radiations. The TL response of the sensitized phosphor was found to be linear to gamma radiation and sublinear to UV radiation. (Auth.)

Quality-assurance techniques used with automated analysis of gamma-ray spectra

International Nuclear Information System (INIS)

Killian, E.W.; Koeppen, L.D.; Femec, D.A.

1994-01-01

In the course of developing gamma-ray spectrum analysis algorithms for use by the Radiation Measurements Laboratory at the Idaho National Engineering Laboratory (INEL), several techniques have been developed that enhance and verify the quality of the analytical results. The use of these quality-assurance techniques is critical when gamma-ray analysis results from low-level environmental samples are used in risk assessment or site restoration and cleanup decisions. This paper describes four of the quality-assurance techniques that are in routine use at the laboratory. They are used for all types of samples, from reactor effluents to environmental samples. The techniques include: (1) the use of precision pulsers (with subsequent removal) to validate the correct operation of the spectrometer electronics for each and every spectrum acquired, (2) the use of naturally occurring and cosmically induced radionuclides in samples to help verify that the data acquisition and analysis were performed properly, (3) the use of an ambient background correction technique that involves superimposing (open-quotes mappingclose quotes) sample photopeak fitting parameters onto multiple background spectra for accurate and more consistent quantification of the background activities, (4) the use of interactive, computer-driven graphics to review the automated locating and fitting of photopeaks and to allow for manual fitting of photopeaks

Possible role of calcium dependent protein phosphorylation in the modulation of wound induced HRGP gene activation in potatoes after gamma irradiation

International Nuclear Information System (INIS)

Ussuf, K.K.; Laxmi, N.H.; Nair, P.M.

1996-01-01

Hydroxyproline rich glycoprotein (HRGP) gene is induced in both control and gamma irradiated potato tubers after wounding. The enhanced RNA synthesis in response to wounding correlated well with the accumulation of both HRGP gene transcripts and protein. Initially, the level of HRGP gene expression in gamma irradiated potatoes in response to wounding was 30% more than the corresponding controls. After post irradiation storage of 3-5 weeks, HRGP gene expression in response to wounding was significantly lower than the unirradiated samples. This low level of HRGP gene expression in irradiated potatoes was partially retrieved by 5 mM Ca 2+ treatment. Prior treatment with trifluoperazine, a calcium channel blocker resulted in 35% reduction in wound induced HRGP gene expression in control potatoes, further providing evidence for the involvement of Ca 2+ dependency for HRGP gene activation. A comparative study on in vivo protein phosphorylation induced by wounding in control and irradiated potatoes exhibited significant differences. A good correlation was observed in the modulation of phosphorylation and HRGP gene expression by Ca 2+ in irradiated potatoes. Wound induced signal transduction system and subsequent Ca 2+ dependent protein phosphorylation for the activation of HRGP gene is affected in potatoes after gamma irradiation, thus impairing the wound healing process adversely. (author). 25 refs., 5 figs

PASSIVE-AVOIDANCE TRAINING INDUCES ENHANCED LEVELS OF IMMUNOREACTIVITY FOR MUSCARINIC ACETYLCHOLINE-RECEPTOR AND COEXPRESSED PKC-GAMMA AND MAP-2 IN RAT CORTICAL-NEURONS

NARCIS (Netherlands)

VANDERZEE, EA; DOUMA, BRK; BOHUS, B; LUITEN, PGM

1994-01-01

Changes in neocortical immunoreactivity (ir) for muscarinic acetylcholine receptors (mAChRs), protein kinase C gamma (PKC gamma), microtubule-associated protein 2 (MAP-2), and the calcium-binding protein parvalbumin (PARV) induced by the performance of a one-trial passive shock avoidance (PSA) task

Body composition to climate change studies - the many facets of neutron induced prompt gamma-ray analysis

International Nuclear Information System (INIS)

Mitra, S.

2008-01-01

In-vivo body composition analysis of humans and animals and in-situ analysis of soil using fast neutron inelastic scattering and thermal neutron capture induced prompt-gamma rays have been described. By measuring carbon (C), nitrogen (N) and oxygen (O), protein, fat and water are determined. C determination in soil has become important for understanding below ground carbon sequestration process in the light of climate change studies. Various neutron sources ranging from radio isotopic to compact 14 MeV neutron generators employing the associated particle neutron time-of-flight technique or micro-second pulsing were implemented. Gamma spectroscopy using recently developed digital multi-channel analyzers has also been described

Body composition to climate change studies - the many facets of neutron induced prompt gamma-ray analysis

Energy Technology Data Exchange (ETDEWEB)

Mitra,S.

2008-11-17

In-vivo body composition analysis of humans and animals and in-situ analysis of soil using fast neutron inelastic scattering and thermal neutron capture induced prompt-gamma rays have been described. By measuring carbon (C), nitrogen (N) and oxygen (O), protein, fat and water are determined. C determination in soil has become important for understanding below ground carbon sequestration process in the light of climate change studies. Various neutron sources ranging from radio isotopic to compact 14 MeV neutron generators employing the associated particle neutron time-of-flight technique or micro-second pulsing were implemented. Gamma spectroscopy using recently developed digital multi-channel analyzers has also been described.

Enhancement of gamma-ray-induced mutation frequency in rice by post-treatment with chloral hydrate, methanol and their mixtures with ethanol

International Nuclear Information System (INIS)

Reddy, T.P.; Vaidyanath, K.

1979-01-01

An evaluation has been made of the mutagenic activity of ethanol, chlorate hydrate (CH) and methanol on rice seed. In independent treatments with ethanol, methanol, CH and four aqueous mixtures of these chemicals, chlorophyll-deficient mutants were not recovered in the M 2 generation. However, in sequential treatments with gamma rays + CH, gamma rays + methanol and gamma rays + aqueous mixtures of these chemicals, significant increases in the yields of chlorophyll mutations were observed as compared to that of a 30 kR gamma ray treatment. In contrast, post-irradiation treatment with ethanol failed to provoke any increase in the frequency of chlorophyll mutants in the M 2 generation. The results indicate that CH and methanol alone and mixed with ethanol can potentiate gamma ray-induced genetic lesions in rice seed. (author)

Acupuncture analgesia involves modulation of pain-induced gamma oscillations and cortical network connectivity.

Science.gov (United States)

Hauck, Michael; Schröder, Sven; Meyer-Hamme, Gesa; Lorenz, Jürgen; Friedrichs, Sunja; Nolte, Guido; Gerloff, Christian; Engel, Andreas K

2017-11-24

Recent studies support the view that cortical sensory, limbic and executive networks and the autonomic nervous system might interact in distinct manners under the influence of acupuncture to modulate pain. We performed a double-blind crossover design study to investigate subjective ratings, EEG and ECG following experimental laser pain under the influence of sham and verum acupuncture in 26 healthy volunteers. We analyzed neuronal oscillations and inter-regional coherence in the gamma band of 128-channel-EEG recordings as well as heart rate variability (HRV) on two experimental days. Pain ratings and pain-induced gamma oscillations together with vagally-mediated power in the high-frequency bandwidth (vmHF) of HRV decreased significantly stronger during verum than sham acupuncture. Gamma oscillations were localized in the prefrontal cortex (PFC), mid-cingulate cortex (MCC), primary somatosensory cortex and insula. Reductions of pain ratings and vmHF-power were significantly correlated with increase of connectivity between the insula and MCC. In contrast, connectivity between left and right PFC and between PFC and insula correlated positively with vmHF-power without a relationship to acupuncture analgesia. Overall, these findings highlight the influence of the insula in integrating activity in limbic-saliency networks with vagally mediated homeostatic control to mediate antinociception under the influence of acupuncture.

{gamma}-Radiation-induced follicular degeneration in the prepubertal mouse ovary

Energy Technology Data Exchange (ETDEWEB)

Lee, Chang Joo [Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Yoon, Yong-Dal [Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of)]. E-mail: ydyoon@hanyang.ac.kr

2005-10-15

Prepubertal mice were whole-body irradiated with a mean lethal dose (LD{sub 50}) of {gamma}-radiation using a {sup 60}Co source with a total dose of 7.2 Gy and a dose rate of 12.0 cGy/min. At day 0 before the irradiation and at day 1, 2, and 3 after the irradiation, the ovaries were collected and the morphological changes were assessed. The ratios (%) of atretic or polymorphonuclear leukocytes (neutrophil)-infiltrated follicles in the largest cross sections were calculated. In the early atretic follicle of the control mouse ovary, both apoptotic and mitotic cells were observed and occasionally neutrophils were infiltrated into the follicle cavity. However, in the atretic follicles 2 days post-irradiation, numerous cell fragments, apoptotic cells and bodies, and especially, a number of neutrophils were observed. In the non-irradiated control, the ratios of atretic follicles were 58.0 {+-} 8.6 and 27.3 {+-} 11.2 (mean {+-} S.E.M.) in antral and preantral follicles, respectively. The ratios of the number of antral and preantral follicles with one or more neutrophils to the total number of atretic follicles were 29.3 {+-} 12.0. At 2 days post-irradiation, the ratios of atretic follicles were increased to 94.0 {+-} 3.4 and 86.9 {+-} 7.6 in antral and preantral follicles, respectively. The ratios of neutrophil-containing follicles among the atretic one were increased to 65.9 {+-} 11.5 and 57.8 {+-} 15.4 at 2 and 3 days after the irradiation, respectively. Taken together, the present results show that {gamma}-radiation induces apoptotic and inflammatory degeneration of mouse ovarian follicles. Besides, neutrophils may be involved in the acute atretic degeneration in {gamma}-irradiated mouse ovarian follicles.

Wheat Germ Oil Attenuates Gamma Radiation- Induced Skeletal Muscles Damage in Rats

International Nuclear Information System (INIS)

Said, U.Z.; Saada, H.N.; Shedid, Sh.M.; Mahdy, E.M.E.; Shousha, W.Gh.

2008-01-01

Muscular strength is important in sport as well as in daily activities. Exposure to ionizing radiation is thought to increase oxidative stress and damage muscle tissue. Wheat germ oil is a natural unrefined vegetable oil. It is an excellent source of vitamin E, octacosanol, linoleic and linolenic essential fatty acids, which may be beneficial in neutralizing the free oxygen radicals. The present study was designed to investigate the efficacy of wheat germ oil, on radiation-induced oxidative damage in rats skeletal muscle. Wheat germ oil was supplemented orally via gavages to rats at a dose of 54 mg/ kg body weight/day for 14 successive days pre- and 7 post-exposure to 5 Gy (one shot dose) of whole body gamma irradiation. Animals were sacrificed 7, 14 and 21 days post radiation exposure. The results revealed that whole body gamma-irradiation of rats induces oxidative stress in skeletal muscles obvious by significant elevation in the level of thiobarbituric acid reactive substances (TBARS) associated with significant decreases in the content of reduced glutathione (GSE1), as well as decreases in superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities. Irradiated rats showed, also, significant decreases in creatine phosphokinase (CPK), glutamate dehydrogenase (GDH) and glucose-6-phosphate dehydrogenase (G-6-PD) activities. Furthermore, total iron, total copper and total calcium levels were significantly increased in skeletal muscles of irradiated rats group compared to control group. Wheat germ oil treated-irradiated rats showed significantly less sever damage and remarkable improvement in all the measured parameters, compared to irradiated rats. It could be concluded that wheat germ oil by attenuating radiation induced oxidative stress might play a role in maintaining skeletal muscle integrity

Radiation dose in the high background radiation area in Kerala, India.

Science.gov (United States)

Christa, E P; Jojo, P J; Vaidyan, V K; Anilkumar, S; Eappen, K P

2012-03-01

A systematic radiological survey has been carried out in the region of high-background radiation area in Kollam district of Kerala to define the natural gamma-radiation levels. One hundred and forty seven soil samples from high-background radiation areas and five samples from normal background region were collected as per standard sampling procedures and were analysed for (238)U, (232)Th and (40)K by gamma-ray spectroscopy. External gamma dose rates at all sampling locations were also measured using a survey meter. The activities of (238)U, (232)Th and (40)K was found to vary from 17 to 3081 Bq kg(-1), 54 to 11976 Bq kg(-1) and BDL (67.4 Bq kg(-1)) to 216 Bq kg(-1), respectively, in the study area. Such heterogeneous distribution of radionuclides in the region may be attributed to the deposition phenomenon of beach sand soil in the region. Radium equivalent activities were found high in several locations. External gamma dose rates estimated from the levels of radionuclides in soil had a range from 49 to 9244 nGy h(-1). The result of gamma dose rate measured at the sampling sites using survey meter showed an excellent correlation with dose rates computed from the natural radionuclides estimated from the soil samples.

Gamma-induced positron annihilation spectroscopy and application to radiation-damaged alloys

International Nuclear Information System (INIS)

Wells, D.P.; Hunt, A.W.; Tchelidze, L.; Kumar, J.; Smith, K.; Thompson, S.; Selim, F.; Williams, J.; Harmon, J.F.; Maloy, S.; Roy, A.

2006-01-01

Radiation damage and other defect studies of materials are limited to thin samples because of inherent limitations of well-established techniques such as diffraction methods and traditional positron annihilation spectroscopy (PAS) [P. Hautojarvi, et al., Positrons in Solids, Springer, Berlin, 1979, K.G. Lynn, et al., Appl. Phys. Lett. 47 (1985) 239]. This limitation has greatly hampered industrial and in-situ applications. ISU has developed new methods that use pair-production to produce positrons throughout the volume of thick samples [F.A. Selim, D.P. Wells, et al., Nucl. Instr. and Meth. B 192 (2002) 197, F.A. Selim, D.P. Wells, et al., Nucl. Instru. Meth. A 495 (2002) 154, F.A. Selim, et al., J. Rad. Phys. Chem. 68 (2004) 427, F.A. Selim, D.P. Wells, et al., Nucl. Instr. and Meth. B 241 (2005) 253, A.W. Hunt, D.P. Wells, et al., Nucl. Instr. and Meth. B. 241 (2005) 262]. Unlike prior work at other laboratories that use bremsstrahlung beams to create positron beams (via pair-production) that are then directed at a sample of interest, we produce electron-positron pairs directly in samples of interest, and eliminate the intermediate step of a positron beam and its attendant penetrability limitations. Our methods include accelerator-based bremsstrahlung-induced pair-production in the sample for positron annihilation energy spectroscopy measurements (PAES), coincident proton-capture gamma-rays (where one of the gammas is used for pair-production in the sample) for positron annihilation lifetime spectroscopy (PALS), or photo-nuclear activation of samples for either type of measurement. The positrons subsequently annihilate with sample electrons, emitting coincident 511 keV gamma-rays [F.A. Selim, D.P. Wells, et al., Nucl. Instr. and Meth. B 192 (2002) 197, F.A. Selim, D.P. Wells, et al., Nucl. Instru. Meth. A 495 (2002) 154, F.A. Selim, et al., J. Rad. Phys. Chem. 68 (2004) 427, F.A. Selim, D.P. Wells, et al., Nucl. Instr. and Meth. B 241 (2005) 253, A.W. Hunt, D

Development of Monte Carlo decay gamma-ray transport calculation system

Energy Technology Data Exchange (ETDEWEB)

Sato, Satoshi [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Kawasaki, Nobuo [Fujitsu Ltd., Tokyo (Japan); Kume, Etsuo [Japan Atomic Energy Research Inst., Center for Promotion of Computational Science and Engineering, Tokai, Ibaraki (Japan)

2001-06-01

In the DT fusion reactor, it is critical concern to evaluate the decay gamma-ray biological dose rates after the reactor shutdown exactly. In order to evaluate the decay gamma-ray biological dose rates exactly, three dimensional Monte Carlo decay gamma-ray transport calculation system have been developed by connecting the three dimensional Monte Carlo particle transport calculation code and the induced activity calculation code. The developed calculation system consists of the following four functions. (1) The operational neutron flux distribution is calculated by the three dimensional Monte Carlo particle transport calculation code. (2) The induced activities are calculated by the induced activity calculation code. (3) The decay gamma-ray source distribution is obtained from the induced activities. (4) The decay gamma-rays are generated by using the decay gamma-ray source distribution, and the decay gamma-ray transport calculation is conducted by the three dimensional Monte Carlo particle transport calculation code. In order to reduce the calculation time drastically, a biasing system for the decay gamma-ray source distribution has been developed, and the function is also included in the present system. In this paper, the outline and the detail of the system, and the execution example are reported. The evaluation for the effect of the biasing system is also reported. (author)

Significant gamma-ray lines from dark matter annihilation

Energy Technology Data Exchange (ETDEWEB)

Duerr, Michael [DESY, Notkestrasse 85, 22607 Hamburg (Germany); Fileviez Perez, Pavel; Smirnov, Juri [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany)

2016-07-01

Gamma-ray lines from dark matter annihilation are commonly seen as a ''smoking gun'' for the particle nature of dark matter. However, in many dark matter models the continuum background from tree-level annihilations makes such a line invisible. I present two simple extensions of the Standard Model where the continuum contributions are suppressed and the gamma-ray lines are easily visible over the continuum background.

γγ background of the Drell-Yan process

International Nuclear Information System (INIS)

Carimalo, C.; Kessler, P.; Parisi, J.

1978-01-01

Considering lepton pair production in nucleon-nucleon or nucleon-nucleus collisions, the mechanism of gamma-gamma materialization is compared with that of quark-antiquark annihilation (Drell-Yan process). The computed predictions show that, whereas the gamma-gamma background of the Drell-Yan process should be at most a few percent in present accelerator experiments, it might become more important for future proton-proton colliding beams of superhigh energies (such as in the ISABELLE project). Several different models of quark-parton distribution functions were used both to compute the Drell-Yan cross-section and to define the inelastic structure functions involved in the gamma-gamma effect; the latter was shown, however, to be relatively model-independent. Finally, the accuracy of the simplified procedure (double equivalent-photon method) applied to the gamma-gamma process was checked, using some data computed through a more precise method by Chen et al. It was shown that errors involved in the calculations should be less than 50%, which is of the order of model fluctuations

THE COSMOLOGICAL IMPACT OF LUMINOUS TeV BLAZARS. I. IMPLICATIONS OF PLASMA INSTABILITIES FOR THE INTERGALACTIC MAGNETIC FIELD AND EXTRAGALACTIC GAMMA-RAY BACKGROUND

Energy Technology Data Exchange (ETDEWEB)

Broderick, Avery E; Chang, Philip; Pfrommer, Christoph [Canadian Institute for Theoretical Astrophysics, 60 St. George Street, Toronto, ON M5S 3H8 (Canada)

2012-06-10

Inverse Compton cascades (ICCs) initiated by energetic gamma rays (E {approx}> 100 GeV) enhance the GeV emission from bright, extragalactic TeV sources. The absence of this emission from bright TeV blazars has been used to constrain the intergalactic magnetic field (IGMF), and the stringent limits placed on the unresolved extragalactic gamma-ray background (EGRB) by Fermi have been used to argue against a large number of such objects at high redshifts. However, these are predicated on the assumption that inverse Compton scattering is the primary energy-loss mechanism for the ultrarelativistic pairs produced by the annihilation of the energetic gamma rays on extragalactic background light photons. Here, we show that for sufficiently bright TeV sources (isotropic-equivalent luminosities {approx}> 10{sup 42} erg s{sup -1}) plasma beam instabilities, specifically the 'oblique' instability, present a plausible mechanism by which the energy of these pairs can be dissipated locally, heating the intergalactic medium. Since these instabilities typically grow on timescales short in comparison to the inverse Compton cooling rate, they necessarily suppress the ICCs. As a consequence, this places a severe constraint on efforts to limit the IGMF from the lack of a discernible GeV bump in TeV sources. Similarly, it considerably weakens the Fermi limits on the evolution of blazar populations. Specifically, we construct a TeV-blazar luminosity function from those objects currently observed and find that it is very well described by the quasar luminosity function at z {approx} 0.1, shifted to lower luminosities and number densities, suggesting that both classes of sources are regulated by similar processes. Extending this relationship to higher redshifts, we show that the magnitude and shape of the EGRB above {approx}10 GeV are naturally reproduced with this particular example of a rapidly evolving TeV-blazar luminosity function.

Molecular determinants of desensitization and assembly of the chimeric GABA(A) receptor subunits (alpha1/gamma2) and (gamma2/alpha1) in combinations with beta2 and gamma2

DEFF Research Database (Denmark)

Elster, L; Kristiansen, U; Pickering, D S

2001-01-01

Two gamma-aminobutyric acid(A) (GABA(A)) receptor chimeras were designed in order to elucidate the structural requirements for GABA(A) receptor desensitization and assembly. The (alpha1/gamma2) and (gamma2/alpha1) chimeric subunits representing the extracellular N-terminal domain of alpha1 or gamma......, as opposed to the staining of the (gamma2/alpha1)-containing receptors, which was only slightly higher than background. To explain this, the (alpha1/gamma2) and (gamma2/alpha1) chimeras may act like alpha1 and gamma2 subunits, respectively, indicating that the extracellular N-terminal segment is important...... for assembly. However, the (alpha1/gamma2) chimeric subunit had characteristics different from the alpha1 subunit, since the (alpha1/gamma2) chimera gave rise to no desensitization after GABA stimulation in whole-cell patch-clamp recordings, which was independent of whether the chimera was expressed...

FT-IR study of gamma-radiation induced degradation of polyvinyl alcohol (PVA) and PVA/humic acids blends

International Nuclear Information System (INIS)

Ilcin, M.; Hola, O.; Bakajova, B.; Kucerik, J.

2010-01-01

Samples of pure polyvinyl alcohol (PVA) and PVA doped with humic acids were exposed to gamma radiation. Gamma rays induced the degradation of the pure polymer. Degradation changes were observed using ATR FT-IR equipment. Dehydration, double bond creation, and their subsequent oxidation (surrounding atmosphere was air) were found out. Also, other degradation reactions (e.g. chain scission, cyclization) occur simultaneously. Formation of C=C and C=O bonds is apparent from FT-IR spectra. In contrast the presence of humic acids in the PVA sample showed stabilizing effect on PVA structure within the concentration range 0.5-10%. (author)

A new possibility of separate the natural and industrial components of the ambient radiation background

International Nuclear Information System (INIS)

Purghel, L.; Valcov, N.; Celarel, A.

1997-01-01

The ambient radiation background, sometimes considered as a gamma-ray background, is actually composed by a natural radiation field and an industrial radiation field, produced by nuclear facilities. This work presents a possibility to separate and to measure simultaneously both components by using the statistical discrimination method. As the statistical discrimination method is able to measure mixed radiation fields, characterized by essentially different statistical factors k = σ 2 / I (I - the mean value and σ 2 - the variance of the ionization current), this basic assumption of the method is checked, for the natural background and the gamma-ray checked, for natural background and the gamma-ray fields. The obtained value of the ratio k B / k γ = 9 has confirmed the validity of the statistical discrimination method as well as the assumption of a small contribution of the gamma-ray field to the ambient radiation background. Some estimations of the statistical uncertainties, associated with the measurement of two components of the ambient background field have been made. For a 10 liters, atmospheric pressure air - filled ionization chamber (or its equivalent, i.e. 2 liters, 5 atmospheres air -filled chamber) and a 30 s integration time constant, the minimum detectable absorbed dose rate of gamma-rays, for a 0.1 μ Gy / h natural background absorbed dose rate, is equal to 0.02 μ Gy / h. The statistical relative uncertainty of measurement for a 0.5 μ Gy / h absorbed dose rate gamma-ray field, corresponding to the admissible value of the equivalent dose rate of 0.6 μ Sv / h, for non-professional population is about 4 %. (authors)

Autoradiographic study of gamma-ray induced unscheduled DNA synthesis in bean root meristem cells

International Nuclear Information System (INIS)

Liu Zhenshen; Qiu Quanfa; Chen Dongli

1989-01-01

The gamma-ray induced unscheduled DNA synthesis in root meristem cells of Vica faba was studied autoradiographically by calculating the number of cells with different 3H-thymidine labelling degree. It was found that the level of unscheduled synthesis in cells with intermediate dose (500 R) irradiation was higher than that in cells with lower dose (250 R) irradiation; however, higher dose (1000 R) irradiation would inhibit the reparative replication

TL glow curve analysis of UV, beta and gamma induced limestone collected from Amarnath holy cave

Directory of Open Access Journals (Sweden)

Vikas Dubey

2015-01-01

Full Text Available The paper reports themoluminescence glow curve analysis of UV (ultraviolet, β (beta and γ (gamma induced limestone collected from Amarnath holy cave. The collected natural sample was characterized by X-ray diffraction (XRD technique and crystallite size calculated by Scherer's formula. Surface morphology and particle size was calculated by transmission electron microscopy (TEM study. Effect of annealing temperature on collected lime stone examined by TL glow curve study. The limestone was irradiated by UV radiation (254 nm source and the TL glow curve recorded for different UV exposure time. For beta irradiation Sr90 source was used and is shows intense peak at 256 °C with a shoulder peak at higher temperature range. For gamma radiation Co60 source and TL glow curve recorded for different doses of gamma. The kinetic parameters calculation was performed for different glow curve by computerized glow curve deconvolution (CGCD technique. The chemical composition of natural limestone was analyzed by energy dispersive X-ray spectroscopy (EDXS.

Measurement of secondary gamma-ray production cross sections of vanadium induced by D-T neutrons

International Nuclear Information System (INIS)

Kondo, Tetsuo; Murata, Isao; Takahashi, Akito

1999-01-01

The secondary gamma-ray production cross sections of vanadium induced by D-T neutrons have been measured. The experimental values were compared with the theoretical calculation results by SINCROS-II and the evaluation result based on experimental data compiled by Simakov. The calculation results supported our data, while Simakov's evaluation did not agree with the present result very well. (author)

Modeling of proton-induced radioactivation background in hard X-ray telescopes: Geant4-based simulation and its demonstration by Hitomi's measurement in a low Earth orbit

Science.gov (United States)

Odaka, Hirokazu; Asai, Makoto; Hagino, Kouichi; Koi, Tatsumi; Madejski, Greg; Mizuno, Tsunefumi; Ohno, Masanori; Saito, Shinya; Sato, Tamotsu; Wright, Dennis H.; Enoto, Teruaki; Fukazawa, Yasushi; Hayashi, Katsuhiro; Kataoka, Jun; Katsuta, Junichiro; Kawaharada, Madoka; Kobayashi, Shogo B.; Kokubun, Motohide; Laurent, Philippe; Lebrun, Francois; Limousin, Olivier; Maier, Daniel; Makishima, Kazuo; Mimura, Taketo; Miyake, Katsuma; Mori, Kunishiro; Murakami, Hiroaki; Nakamori, Takeshi; Nakano, Toshio; Nakazawa, Kazuhiro; Noda, Hirofumi; Ohta, Masayuki; Ozaki, Masanobu; Sato, Goro; Sato, Rie; Tajima, Hiroyasu; Takahashi, Hiromitsu; Takahashi, Tadayuki; Takeda, Shin'ichiro; Tanaka, Takaaki; Tanaka, Yasuyuki; Terada, Yukikatsu; Uchiyama, Hideki; Uchiyama, Yasunobu; Watanabe, Shin; Yamaoka, Kazutaka; Yasuda, Tetsuya; Yatsu, Yoichi; Yuasa, Takayuki; Zoglauer, Andreas

2018-05-01

Hard X-ray astronomical observatories in orbit suffer from a significant amount of background due to radioactivation induced by cosmic-ray protons and/or geomagnetically trapped protons. Within the framework of a full Monte Carlo simulation, we present modeling of in-orbit instrumental background which is dominated by radioactivation. To reduce the computation time required by straightforward simulations of delayed emissions from activated isotopes, we insert a semi-analytical calculation that converts production probabilities of radioactive isotopes by interaction of the primary protons into decay rates at measurement time of all secondary isotopes. Therefore, our simulation method is separated into three steps: (1) simulation of isotope production, (2) semi-analytical conversion to decay rates, and (3) simulation of decays of the isotopes at measurement time. This method is verified by a simple setup that has a CdTe semiconductor detector, and shows a 100-fold improvement in efficiency over the straightforward simulation. To demonstrate its experimental performance, the simulation framework was tested against data measured with a CdTe sensor in the Hard X-ray Imager onboard the Hitomi X-ray Astronomy Satellite, which was put into a low Earth orbit with an altitude of 570 km and an inclination of 31°, and thus experienced a large amount of irradiation from geomagnetically trapped protons during its passages through the South Atlantic Anomaly. The simulation is able to treat full histories of the proton irradiation and multiple measurement windows. The simulation results agree very well with the measured data, showing that the measured background is well described by the combination of proton-induced radioactivation of the CdTe detector itself and thick Bi4Ge3O12 scintillator shields, leakage of cosmic X-ray background and albedo gamma-ray radiation, and emissions from naturally contaminated isotopes in the detector system.

Modification of reconstructed gamma-jets in heavy-ion collisions

Energy Technology Data Exchange (ETDEWEB)

Luo, Tan; He, Yayun; Wang, Enke [Key Laboratory of Quark and Lepton Physics (MOE) and Institute of Particle Physics, Central China Normal University, Wuhan 430079 (China); Wang, Xin-Nian [Key Laboratory of Quark and Lepton Physics (MOE) and Institute of Particle Physics, Central China Normal University, Wuhan 430079 (China); Nuclear Science Division Mailstop 70R0319, Lawrence Berkeley National Laboratory, Berkeley, CA 94740 (United States)

2016-12-15

We use the Linear Boltzmann Transport model to study gamma-triggered jets in high-energy heavy-ion collisions. Since both recoiled partons from elastic scattering and radiated gluons from inelastic processes and their further propagation are considered, the model can provide a description of not only the medium modification of reconstructed jets but also the energy flow in the underlying hydrodynamic background. In this study, we discuss the modification of jet shape and jet fragmentation function of γ-jet in central Pb+Pb collisions and in particular the energy flow induced by the jet-medium interaction.

P53 suppresses expression of the 14-3-3gamma oncogene

Directory of Open Access Journals (Sweden)

Qi Wenqing

2011-08-01

Full Text Available Abstract Background 14-3-3 proteins are a family of highly conserved proteins that are involved in a wide range of cellular processes. Recent evidence indicates that some of these proteins have oncogenic activity and that they may promote tumorigenesis. We previously showed that one of the 14-3-3 family members, 14-3-3gamma, is over expressed in human lung cancers and that it can induce transformation of rodent cells in vitro. Methods qRTPCR and Western blot analysis were performed to examine 14-3-3gamma expression in non-small cell lung cancers (NSCLC. Gene copy number was analyzed by qPCR. P53 mutations were detected by direct sequencing and also by western blot. CHIP and yeast one hybrid assays were used to detect p53 binding to 14-3-3gamma promoter. Results Quantitative rtPCR results showed that the expression level of 14-3-3gamma was elevated in the majority of NSCLC that we examined which was also consistent with protein expression. Further analysis of the expression pattern of 14-3-3gamma in lung tumors showed a correlation with p53 mutations suggesting that p53 might suppress 14-3-3 gamma expression. Analysis of the gamma promoter sequence revealed the presence of a p53 consensus binding motif and in vitro assays demonstrated that wild-type p53 bound to this motif when activated by ionizing radiation. Deletion of the p53 binding motif eliminated p53's ability to suppress 14-3-3gamma expression. Conclusion Increased expression of 14-3-3gamma in lung cancer coincides with loss of functional p53. Hence, we propose that 14-3-3gamma's oncogenic activities cooperate with loss of p53 to promote lung tumorigenesis.

Study of the $K^{\\pm} \\rightarrow \\pi^{\\pm} \\gamma \\gamma$ decay by the NA62 experiment

CERN Document Server

INSPIRE-00100355; Romano, A.; Ceccucci, A.; Danielsson, H.; Falaleev, V.; Gatignon, L.; Goy Lopez, S.; Hallgren, B.; Maier, A.; Peters, A.; Piccini, M.; Riedler, P.; Frabetti, P.L.; Gersabeck, E.; Kekelidze, V.; Madigozhin, D.; Misheva, M.; Molokanova, N.; Movchan, S.; Shkarovskiy, S.; Zinchenko, A.; Rubin, P.; Baldini, W.; Cotta Ramusino, A.; Dalpiaz, P.; Fiorini, M.; Gianoli, A.; Norton, A.; Petrucci, F.; Savrie, M.; Wahl, H.; Bizzeti, A.; Bucci, F.; Iacopini, E.; Lenti, M.; Veltri, M.; Antonelli, A.; Moulson, M.; Raggi, M.; Spadaro, T.; Eppard, K.; Hita-Hochgesand, M.; Kleinknecht, K.; Renk, B.; Wanke, R.; Winhart, A.; Winston, R.; Bolotov, V.; Duk, V.; Gushchin, E.; Ambrosino, F.; Di Filippo, D.; Massarotti, P.; Napolitano, M.; Palladino, V.; Saracino, G.; Anzivino, G.; Imbergamo, E.; Piandani, R.; Sergi, A.; Cenci, P.; Pepe, M.; Costantini, F.; Doble, N.; Giudici, S.; Pierazzini, G.; Sozzi, M.; Venditti, S.; Balev, S.; Collazuol, G.; Di, L.; Gallorini, S.; Goudzovski, E.; Lamanna, G.; Mannelli, I.; Ruggiero, G.; Cerri, C.; Fantechi, R.; Kholodenko, S.; Kurshetsov, V.; Obraztsov, V.; Semenov, V.; Yushchenko, O.; D'Agostini, G.; Leonardi, E.; Serra, M.; Valente, P.; Fucci, A.; Salamon, A.; Bloch-Devaux, B.; Peyaud, B.; Engelfried, J.; Coward, D.; Kozhuharov, V.; Litov, L.; Arcidiacono, R.; Bifani, S.; Biino, C.; Dellacasa, G.; Marchetto, F.; Numao, T.; Retiere, F.

2014-05-01

A study of the dynamics of the rare decay $K^\\pm\\to\\pi^\\pm\\gamma\\gamma$ has been performed on a sample of 232 decay candidates, with an estimated background of $17.4\\pm1.1$ events, collected by the NA62 experiment at CERN in 2007. The results are combined with those from a measurement conducted by the NA48/2 collaboration at CERN. The combined model-independent branching ratio in the kinematic range $z=(m_{\\gamma\\gamma}/m_K)^2>0.2$ is ${\\cal B}_{\\rm MI}(z>0.2) = (0.965 \\pm 0.063) \\times 10^{-6}$, and the combined branching ratio in the full kinematic range assuming a Chiral Perturbation Theory description is ${\\cal B}(K_{\\pi\\gamma\\gamma}) = (1.003 \\pm 0.056) \\times 10^{-6}$. A detailed comparison of the results with the previous measurements is performed.

Critical role of FcR gamma-chain, LAT, PLCgamma2 and thrombin in arteriolar thrombus formation upon mild, laser-induced endothelial injury in vivo.

Science.gov (United States)

Kalia, Neena; Auger, Jocelyn M; Atkinson, Ben; Watson, Steve P

2008-05-01

The role of collagen receptor complex GPVI-FcR gamma-chain, PLCgamma2 and LAT in laser-induced thrombosis is unclear. Controversy surrounds whether collagen is exposed in this model or whether thrombosis is dependent on thrombin. This study hypothesized that collagen exposure plays a critical role in thrombus formation in this model, which was tested by investigating contributions of FcR gamma-chain, LAT, PLCgamma2 and thrombin. Thrombi were monitored using intravital microscopy in anesthetized wild-type and FcR gamma-chain, LAT and PLCgamma2 knockout mice. Hirudin (thrombin inhibitor) was administered to wild-type and FcR gamma-chain knockout mice. Significantly reduced thrombus formation was observed in FcR gamma-chain and PLCgamma2 knockouts with a greater decrease observed in LAT knockouts. Dramatic reduction was observed in wild-types treated with hirudin, with abolished thrombus formation only observed in FcR gamma-chain knockouts treated with hirudin. GPVI-FcR gamma-chain, LAT and PLCgamma2 are essential for thrombus generation and stability in this laser-induced model of injury. More importantly, a greater role for LAT was identified, which may reflect a role for it downstream of a second matrix protein receptor. However, inhibition of platelet activation by matrix proteins and thrombin generation are both required to maximally prevent thrombus formation.

Gamma radiation induced and natural variability for nodulation in legumes

Energy Technology Data Exchange (ETDEWEB)

Maherchandani, N; Rana, O P.S. [Haryana Agricultural Univ., Hissar (India). Dept. of Genetics

1977-09-01

Gamma radiation induced variability for nodulation was studied in 112 M4 mutant lines of cowpea variety C-15-2. Ten lines superior in nodulation to the original variety have been identified. Natural variability for nodulation and plant growth was investigated in 75 genotypes of chickpea. A number of genotype were found to be superior to cultivated variety C-235 for nodulation characters. Nodule characters were found to be related to dry matter accumulation but not to grain yield. Another experiment on 10 varieties of chick pea conducted under aseptic conditions revealed that host genotypes showed specificity for Rhizobial strains and different Rhizobial strains differed in their effectiveness on different host genotypes. H 551 and H 355 were the most responsive varieties.

Low level GAMMA0 spectrometry by beta-gamma coincidence

International Nuclear Information System (INIS)

Grigorescu, E.L.; Luca, A.; Razdolescu, A.C.; Ivan, C.

1999-01-01

Low level gamma spectrometry has a wide application, especially in environmental monitoring. Two variants, based on a beta-gamma coincidence technique, were studied. The equipment was composed of a beta detector and a Ge(Li) gamma detector (6% - relative efficiency), with the associated electronics. The gamma rays are recorded by the multichannel analyzer (4096 channels) only if the associated beta particles, which precede the gamma transitions, are registered in coincidence. Two types of beta detectors were used: plastic and liquid scintillators. In both cases, an external lead shield of 5 cm thick was used. The integral gamma background (50-1700 KeV) was reduced about 85 and 50 times, respectively. The corresponding MDA (Minimum Detectable Activity) values decreased about 1.5 and (3-7) times, respectively. The 2π sr plastic beta detector was placed on top the Ge(Li). The sample was inserted between the two detectors. The measurement time was 10 4 s. A 4π sr detector, built of the same material, was also studied, but it proved to be less advantageous because the background was reduced only 16 times; for a MDA reduction similar with that of the 2π sr variant, a longer measurement was needed (3.10 4 s). The other type of beta detector used, was a liquid scintillator. The dissolving of the samples in scintillator ensures a 4π sr measurement geometry. The vials with scintillator (10 ml volume) were placed on top the Ge(Li) and visualised by the photocathode of a phototube. This setup was surrounded by an enclosure which prevent the light penetration. The measurement time was 10 4 s. The only difficulty encountered in this low level measurement method is the accurate determination of the beta efficiency. A limitation is the possibility to measure only small mass samples. These variants are more simple and cheaper than others, previously studied. The advantage of the method is obvious when, instead of low MDA values, shorter measurement times are preferred. The

The emission of Gamma Ray Bursts as a test-bed for modified gravity

Directory of Open Access Journals (Sweden)

S. Capozziello

2015-11-01

Full Text Available The extreme physical conditions of Gamma Ray Bursts can constitute a useful observational laboratory to test theories of gravity where very high curvature regimes are involved. Here we propose a sort of curvature engine capable, in principle, of explaining the huge energy emission of Gamma Ray Bursts. Specifically, we investigate the emission of radiation by charged particles non-minimally coupled to the gravitational background where higher order curvature invariants are present. The coupling gives rise to an additional force inducing a non-geodesic motion of particles. This fact allows a strong emission of radiation by gravitationally accelerated particles. As we will show with some specific model, the energy emission is of the same order of magnitude of that characterizing the Gamma Ray Burst physics. Alternatively, strong curvature regimes can be considered as a natural mechanism for the generation of highly energetic astrophysical events. Possible applications to cosmology are discussed.

Upgrade of the JET gamma-ray cameras

International Nuclear Information System (INIS)

Soare, S.; Curuia, M.; Anghel, M.; Constantin, M.; David, E.; Craciunescu, T.; Falie, D.; Pantea, A.; Tiseanu, I.; Kiptily, V.; Prior, P.; Edlington, T.; Griph, S.; Krivchenkov, Y.; Loughlin, M.; Popovichev, S.; Riccardo, V; Syme, B.; Thompson, V.; Lengar, I.; Murari, A.; Bonheure, G.; Le Guern, F.

2007-01-01

JET GRC. The modelling was dedicated to the estimation of neutron and (plasma-emitted) gamma-ray attenuation, neutron-induced gamma-ray background and the neutron in-scattering impact on the neutron detectors due to the attenuator in the parking location. A numerical study of the gamma-ray detector (CsI(Tl)) was done by means of the IST Monte Carlo code. It provided preliminary results on the detector efficiency and response function. (authors)

Prospects of squark and slepton searches at a gamma-gamma collider

International Nuclear Information System (INIS)

Choudhury, Debajyoti; Datta, Anindya

2001-01-01

We examine the prospects of detecting sfermions at a gamma-gamma collider. Once produced, a slepton can decay into a pair of quarks (jets) through R-parity violating interactions. Similarly, a squark may decay into a lepton-quark pair. Analyzing the corresponding Standard Model backgrounds, namely 4-jet and dilepton plus dijet final states respectively, we show that the sfermion can be detected almost right upto the kinematic limit and its mass determined to a fair degree of accuracy. Similar statements also hold for nonsupersymmetric leptoquarks and diquarks

Action of the chlorophyllin before genetic damage induced by gamma radiation in germinal cells of Drosophila

International Nuclear Information System (INIS)

Moreno B, R.

2004-01-01

The chlorophyllin (CHLN) is a porphyrin of nutritious grade and soluble in water, derived of the chlorophyll. It has been reported that this pigment is a good anti mutagen since it reduces the damage to the DNA caused by physical or chemical agents of direct or indirect action. Their anti carcinogenic action has also been demonstrated when it is administered itself during the induced post-initiation phase by aflatoxins and heterocyclic amines. However in the last decade it has been reported that it also has promoter activity against the genetic damage induced by diverse agents like the alkyl ants of direct and indirect action, the gamma radiation and some heterocyclic amines. This effect has been observed in testing systems like Salmonella, Drosophila, rainbow trout and rodents. In the mouse spermatogonia it has been reported that it reduces the damage to the DNA but with the test of lethal dominant in Drosophila increment the damage induced by gamma radiation. The present study consisted on evaluating the effect of the CHLN in the line germinal masculine of Drosophila by means of the lethal recessive test bound to the sex (LRLS) with the stump Muller 5 and a litters system. Its were pretreated wild males with CHLN and 24 h later were irradiated with 0, 10, 20 and 40 Gy of gamma radiation immediately later were crossed with virgin females of the stump Basc and at 72 h the male was transferred to a cultivation media with three new virgin females, this process repeated three times until completing 3 litters. The F1 it was crossed among itself and in the F2 it was analysed the presence or absence of lethals. The results indicated that the CHLN per se incremented the basal frequency of damage due to the pigment can act as an agent that is inserted to the ADN causing pre mutagenic leisure. Nevertheless with the groups treated with the different doses of gamma radiation the CHLN does not present any protector action, neither promoter except in the litter I of the group

Induced mitotic gynogenesis in common carp (Cyprinus carpio L.), optimizing irradiation dose of X- and gamma-ray

International Nuclear Information System (INIS)

Yousefian, M.; Amirinia, C.; Bercsenyi, M.; Horvath, L.

1997-01-01

Mitotic gynogenesis was induced in common carp, Cyprinus carpio L., in hatchery and laboratory conditions, using 60Co gamma-ray and X-ray for inactivation of sperm DNA and a subsequent heat shock for inducing endomitosis. The parameter examined was the dose of irradiation in the range of 70-140 Krad. Carp spermatozoa irradiated by 70-100 Krad doses showed higher motility and fertilization ability than the ones irradiated by 110-140 Krad. Sperm treated with doses of 70-90 Krad showed the same fertility rate, but lower survival rate at embryo stage compared with 100 Krad. The shock temperature and duration applied in these experiments for restoration of diploidy level were 40 degrees C plus/minus 0.1 and 2 min., respectively. The highest frequency of mitotic gynogenetic larvae was achieved by 100 Krad 60Co gamma ray at 34 min. after fertilization, - up to 12.2 percent (at 23 degrees C incubating temperature)

Study of the grain boundary widening in YBaCuO superconducting ceramics induced by gamma rays

International Nuclear Information System (INIS)

Cruz Inclan, Carlos M.; Leyva Fabelo, Antonio

2001-01-01

The behavior of the thickness of the weak link with the irradiation dose was explained qualitatively and quantitatively using the migration model of the defects in the superconducting grains stimulated by the action of the gamma rays. The value of the diffusion constant associated with the migration, obtained through this model, results higher than the reported value in the literature. This difference may be associated with a notable reduction in the activation energy of the process. It was demonstrated that the variations induced by the gamma radiation in the transition width and in the critical temperature, measured by transportation methods, do not have any influence in the behavior of the intergrain link with the irradiation doses

POISONING WITH GAMMA-HYDROXYBUTYRATE, GAMMA-BUTYROLACTONE AND 1.4-BUTANDIOL

Directory of Open Access Journals (Sweden)

Miran Brvar

2002-09-01

Full Text Available Background. Gamma-hydroxybutyrate (GHB is a popular recreational drug. GHB overdose typically presents with decreased level of consciousness, miosis, bradycardia, respiratory depression and death. Typically, combativeness, confusion and vomiting occur once the patient begins to recover. Gamma-butyrolactone (GBL and 1.4-butandiol (1.4-BD are the prodrugs of GHB and have similar clinical presentation. We present the case of GHB poisoning in Ljubljana.Conclusions. Physicians should suspect GHB poisoning in young ravers who present with CNS depression. Treatment is symptomatic. There is no specific antidote. Gastric lavage is not beneficial but activated charcoal is recommended.

Gamma radiation induces growth retardation, impaired egg production, and oxidative stress in the marine copepod Paracyclopina nana

Energy Technology Data Exchange (ETDEWEB)

Won, Eun-Ji; Lee, Jae-Seong, E-mail: jslee2@skku.edu

2014-05-01

Highlights: • Mortality was increased with a dose dependent manner in ovigerous females of Paracyclopina nana. • Developmental impairments were observed in gamma irradiated nauplii. • Ovigerous females exposed to more than 50 Gy could not have normal two bilateral egg sacs. • Oxidative levels increased with antioxidant enzyme activities in the gamma irradiated P. nana. • The molecular indices (antioxidant enzymes and heat shock protein) were also increased. - Abstract: Accidental nuclear radioisotope release into the ocean from nuclear power plants is of concern due to ecological and health risks. In this study, we used the marine copepod Paracyclopina nana to examine the effects of radioisotopes on marine organisms upon gamma radiation, and to measure the effects on growth and fecundity, which affect population and community structure. Upon gamma radiation, mortality (LD50 – 96 h = 172 Gy) in P. nana was significantly increased in a dose-dependent manner in ovigerous P. nana females. For developmental impairment of gamma-irradiated nauplii, we observed growth retardation; in over 30 Gy-irradiated groups, offspring did not grow to adults. Particularly, over 50 Gy-irradiated ovigerous P. nana females did not have normal bilateral egg sacs, and their offspring did not develop normally to adulthood. Additionally, at over 30 Gy, we found dose-dependent increases in oxidative levels with elevated antioxidant enzyme activities and DNA repair activities. These findings indicate that gamma radiation can induce oxidative stress and DNA damage with growth retardation and impaired reproduction.

Gamma radiation induces growth retardation, impaired egg production, and oxidative stress in the marine copepod Paracyclopina nana

International Nuclear Information System (INIS)

Won, Eun-Ji; Lee, Jae-Seong

2014-01-01

Highlights: • Mortality was increased with a dose dependent manner in ovigerous females of Paracyclopina nana. • Developmental impairments were observed in gamma irradiated nauplii. • Ovigerous females exposed to more than 50 Gy could not have normal two bilateral egg sacs. • Oxidative levels increased with antioxidant enzyme activities in the gamma irradiated P. nana. • The molecular indices (antioxidant enzymes and heat shock protein) were also increased. - Abstract: Accidental nuclear radioisotope release into the ocean from nuclear power plants is of concern due to ecological and health risks. In this study, we used the marine copepod Paracyclopina nana to examine the effects of radioisotopes on marine organisms upon gamma radiation, and to measure the effects on growth and fecundity, which affect population and community structure. Upon gamma radiation, mortality (LD50 – 96 h = 172 Gy) in P. nana was significantly increased in a dose-dependent manner in ovigerous P. nana females. For developmental impairment of gamma-irradiated nauplii, we observed growth retardation; in over 30 Gy-irradiated groups, offspring did not grow to adults. Particularly, over 50 Gy-irradiated ovigerous P. nana females did not have normal bilateral egg sacs, and their offspring did not develop normally to adulthood. Additionally, at over 30 Gy, we found dose-dependent increases in oxidative levels with elevated antioxidant enzyme activities and DNA repair activities. These findings indicate that gamma radiation can induce oxidative stress and DNA damage with growth retardation and impaired reproduction

Characterisation and mitigation of beam-induced backgrounds observed in the ATLAS detector during the 2011 proton-proton run

CERN Document Server

Aad, Georges; Abbott, Brad; Abdallah, Jalal; Abdel Khalek, Samah; Abdelalim, Ahmed Ali; Abdinov, Ovsat; Aben, Rosemarie; Abi, Babak; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Addy, Tetteh; Adelman, Jahred; Adomeit, Stefanie; Adragna, Paolo; Adye, Tim; Aefsky, Scott; Aguilar-Saavedra, Juan Antonio; Agustoni, Marco; Aharrouche, Mohamed; Ahlen, Steven; Ahles, Florian; Ahmad, Ashfaq; Ahsan, Mahsana; Aielli, Giulio; Akdogan, Taylan; Åkesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Alam, Mohammad; Alam, Muhammad Aftab; Albert, Justin; Albrand, Solveig; Aleksa, Martin; Aleksandrov, Igor; Alessandria, Franco; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Aliev, Malik; Alimonti, Gianluca; Alison, John; Allbrooke, Benedict; Allport, Phillip; Allwood-Spiers, Sarah; Almond, John; Aloisio, Alberto; Alon, Raz; Alonso, Alejandro; Alonso, Francisco; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; Alviggi, Mariagrazia; Amako, Katsuya; Amelung, Christoph; Ammosov, Vladimir; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amram, Nir; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Andrieux, Marie-Laure; Anduaga, Xabier; Angelidakis, Stylianos; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aoun, Sahar; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Arce, Ayana; Arfaoui, Samir; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Engin; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arnault, Christian; Artamonov, Andrei; Artoni, Giacomo; Arutinov, David; Asai, Shoji; Ask, Stefan; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astbury, Alan; Atkinson, Markus; Aubert, Bernard; Auge, Etienne; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Avramidou, Rachel Maria; Axen, David; Azuelos, Georges; Azuma, Yuya; Baak, Max; Baccaglioni, Giuseppe; Bacci, Cesare; Bach, Andre; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Backus Mayes, John; Badescu, Elisabeta; Bagnaia, Paolo; Bahinipati, Seema; Bai, Yu; Bailey, David; Bain, Travis; Baines, John; Baker, Oliver Keith; Baker, Mark; Baker, Sarah; Balek, Petr; Banas, Elzbieta; Banerjee, Piyali; Banerjee, Swagato; Banfi, Danilo; Bangert, Andrea Michelle; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barbaro Galtieri, Angela; Barber, Tom; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Bardin, Dmitri; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Barrillon, Pierre; Bartoldus, Rainer; Barton, Adam Edward; Bartsch, Valeria; Basye, Austin; Bates, Richard; Batkova, Lucia; Batley, Richard; Battaglia, Andreas; Battistin, Michele; Bauer, Florian; Bawa, Harinder Singh; Beale, Steven; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Anne Kathrin; Becker, Sebastian; Beckingham, Matthew; Becks, Karl-Heinz; Beddall, Andrew; Beddall, Ayda; Bedikian, Sourpouhi; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Begel, Michael; Behar Harpaz, Silvia; Behera, Prafulla; Beimforde, Michael; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellomo, Massimiliano; Belloni, Alberto; Beloborodova, Olga; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Benoit, Mathieu; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Berglund, Elina; Beringer, Jürg; Bernat, Pauline; Bernhard, Ralf; Bernius, Catrin; Berry, Tracey; Bertella, Claudia; Bertin, Antonio; Bertolucci, Federico; Besana, Maria Ilaria; Besjes, Geert-Jan; Besson, Nathalie; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Bierwagen, Katharina; Biesiada, Jed; Biglietti, Michela; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Biscarat, Catherine; Bittner, Bernhard; Black, Kevin; Blair, Robert; Blanchard, Jean-Baptiste; Blanchot, Georges; Blazek, Tomas; Bloch, Ingo; Blocker, Craig; Blocki, Jacek; Blondel, Alain; Blum, Walter; Blumenschein, Ulrike; Bobbink, Gerjan; Bobrovnikov, Victor; Bocchetta, Simona Serena; Bocci, Andrea; Boddy, Christopher Richard; Boehler, Michael; Boek, Jennifer; Boek, Thorsten Tobias; Boelaert, Nele; Bogaerts, Joannes Andreas; Bogdanchikov, Alexander; Bogouch, Andrei; Bohm, Christian; Bohm, Jan; Boisvert, Veronique; Bold, Tomasz; Boldea, Venera; Bolnet, Nayanka Myriam; Bomben, Marco; Bona, Marcella; Boonekamp, Maarten; Bordoni, Stefania; Borer, Claudia; Borisov, Anatoly; Borissov, Guennadi; Borjanovic, Iris; Borri, Marcello; Borroni, Sara; Bortfeldt, Jonathan; Bortolotto, Valerio; Bos, Kors; Boscherini, Davide; Bosman, Martine; Boterenbrood, Hendrik; Bouchami, Jihene; Boudreau, Joseph; Bouhova-Thacker, Evelina Vassileva; Boumediene, Djamel Eddine; Bourdarios, Claire; Bousson, Nicolas; Boveia, Antonio; Boyd, James; Boyko, Igor; Bozovic-Jelisavcic, Ivanka; Bracinik, Juraj; Branchini, Paolo; Brandt, Andrew; Brandt, Gerhard; Brandt, Oleg; Bratzler, Uwe; Brau, Benjamin; Brau, James; Braun, Helmut; Brazzale, Simone Federico; Brelier, Bertrand; Bremer, Johan; Brendlinger, Kurt; Brenner, Richard; Bressler, Shikma; Britton, Dave; Brochu, Frederic; Brock, Ian; Brock, Raymond; Broggi, Francesco; Bromberg, Carl; Bronner, Johanna; Brooijmans, Gustaaf; Brooks, Timothy; Brooks, William; Brown, Gareth; Brown, Heather; Bruce, Roderik; Bruckman de Renstrom, Pawel; Bruncko, Dusan; Bruneliere, Renaud; Brunet, Sylvie; Bruni, Alessia; Bruni, Graziano; Bruschi, Marco; Buanes, Trygve; Buat, Quentin; Bucci, Francesca; Buchanan, James; Buchholz, Peter; Buckingham, Ryan; Buckley, Andrew; Buda, Stelian Ioan; Budagov, Ioulian; Budick, Burton; Büscher, Volker; Bugge, Lars; Bulekov, Oleg; Bundock, Aaron Colin; Bunse, Moritz; Buran, Torleiv; Burckhart, Helfried; Burdin, Sergey; Burgess, Thomas; Burke, Stephen; Busato, Emmanuel; Bussey, Peter; Buszello, Claus-Peter; Butler, Bart; Butler, John; Buttar, Craig; Butterworth, Jonathan; Buttinger, William; Byszewski, Marcin; Cabrera Urbán, Susana; Caforio, Davide; Cakir, Orhan; Calafiura, Paolo; Calderini, Giovanni; Calfayan, Philippe; Calkins, Robert; Caloba, Luiz; Caloi, Rita; Calvet, David; Calvet, Samuel; Camacho Toro, Reina; Camarri, Paolo; Cameron, David; Caminada, Lea Michaela; Caminal Armadans, Roger; Campana, Simone; Campanelli, Mario; Canale, Vincenzo; Canelli, Florencia; Canepa, Anadi; Cantero, Josu; Cantrill, Robert; Capasso, Luciano; Capeans Garrido, Maria Del Mar; Caprini, Irinel; Caprini, Mihai; Capriotti, Daniele; Capua, Marcella; Caputo, Regina; Cardarelli, Roberto; Carli, Tancredi; Carlino, Gianpaolo; Carminati, Leonardo; Caron, Bryan; Caron, Sascha; Carquin, Edson; Carrillo-Montoya, German D; Carter, Antony; Carter, Janet; Carvalho, João; Casadei, Diego; Casado, Maria Pilar; Cascella, Michele; Caso, Carlo; Castaneda Hernandez, Alfredo Martin; Castaneda-Miranda, Elizabeth; Castillo Gimenez, Victoria; Castro, Nuno Filipe; Cataldi, Gabriella; Catastini, Pierluigi; Catinaccio, Andrea; Catmore, James; Cattai, Ariella; Cattani, Giordano; Caughron, Seth; Cavaliere, Viviana; Cavalleri, Pietro; Cavalli, Donatella; Cavalli-Sforza, Matteo; Cavasinni, Vincenzo; Ceradini, Filippo; Santiago Cerqueira, Augusto; Cerri, Alessandro; Cerrito, Lucio; Cerutti, Fabio; Cetin, Serkant Ali; Chafaq, Aziz; Chakraborty, Dhiman; Chalupkova, Ina; Chan, Kevin; Chang, Philip; Chapleau, Bertrand; Chapman, John Derek; Chapman, John Wehrley; Chareyre, Eve; Charlton, Dave; Chavda, Vikash; Chavez Barajas, Carlos Alberto; Cheatham, Susan; Chekanov, Sergei; Chekulaev, Sergey; Chelkov, Gueorgui; Chelstowska, Magda Anna; Chen, Chunhui; Chen, Hucheng; Chen, Shenjian; Chen, Xin; Chen, Yujiao; Cheng, Yangyang; Cheplakov, Alexander; Cherkaoui El Moursli, Rajaa; Chernyatin, Valeriy; Cheu, Elliott; Cheung, Sing-Leung; Chevalier, Laurent; Chiefari, Giovanni; Chikovani, Leila; Childers, John Taylor; Chilingarov, Alexandre; Chiodini, Gabriele; Chisholm, Andrew; Chislett, Rebecca Thalatta; Chitan, Adrian; Chizhov, Mihail; Choudalakis, Georgios; Chouridou, Sofia; Christidi, Ilektra-Athanasia; Christov, Asen; Chromek-Burckhart, Doris; Chu, Ming-Lee; Chudoba, Jiri; Ciapetti, Guido; Ciftci, Abbas Kenan; Ciftci, Rena; Cinca, Diane; Cindro, Vladimir; Ciocca, Claudia; Ciocio, Alessandra; Cirilli, Manuela; Cirkovic, Predrag; Citron, Zvi Hirsh; Citterio, Mauro; Ciubancan, Mihai; Clark, Allan G; Clark, Philip James; Clarke, Robert; Cleland, Bill; Clemens, Jean-Claude; Clement, Benoit; Clement, Christophe; Coadou, Yann; Cobal, Marina; Coccaro, Andrea; Cochran, James H; Coffey, Laurel; Cogan, Joshua Godfrey; Coggeshall, James; Cogneras, Eric; Colas, Jacques; Cole, Stephen; Colijn, Auke-Pieter; Collins, Neil; Collins-Tooth, Christopher; Collot, Johann; Colombo, Tommaso; Colon, German; Compostella, Gabriele; Conde Muiño, Patricia; Coniavitis, Elias; Conidi, Maria Chiara; Consonni, Sofia Maria; Consorti, Valerio; Constantinescu, Serban; Conta, Claudio; Conti, Geraldine; Conventi, Francesco; Cooke, Mark; Cooper, Ben; Cooper-Sarkar, Amanda; Copic, Katherine; Cornelissen, Thijs; Corradi, Massimo; Corriveau, Francois; Cortes-Gonzalez, Arely; Cortiana, Giorgio; Costa, Giuseppe; Costa, María José; Costanzo, Davide; Côté, David; Courneyea, Lorraine; Cowan, Glen; Cowden, Christopher; Cox, Brian; Cranmer, Kyle; Crescioli, Francesco; Cristinziani, Markus; Crosetti, Giovanni; Crépé-Renaudin, Sabine; Cuciuc, Constantin-Mihai; Cuenca Almenar, Cristóbal; Cuhadar Donszelmann, Tulay; Cummings, Jane; Curatolo, Maria; Curtis, Chris; Cuthbert, Cameron; Cwetanski, Peter; Czirr, Hendrik; Czodrowski, Patrick; Czyczula, Zofia; D'Auria, Saverio; D'Onofrio, Monica; D'Orazio, Alessia; Da Cunha Sargedas De Sousa, Mario Jose; Da Via, Cinzia; Dabrowski, Wladyslaw; Dafinca, Alexandru; Dai, Tiesheng; Dallapiccola, Carlo; Dam, Mogens; Dameri, Mauro; Damiani, Daniel; Danielsson, Hans Olof; Dao, Valerio; Darbo, Giovanni; Darlea, Georgiana Lavinia; Dassoulas, James; Davey, Will; Davidek, Tomas; Davidson, Nadia; Davidson, Ruth; Davies, Eleanor; Davies, Merlin; Davignon, Olivier; Davison, Adam; Davygora, Yuriy; Dawe, Edmund; Dawson, Ian; Daya-Ishmukhametova, Rozmin; De, Kaushik; de Asmundis, Riccardo; De Castro, Stefano; De Cecco, Sandro; de Graat, Julien; De Groot, Nicolo; de Jong, Paul; De La Taille, Christophe; De la Torre, Hector; De Lorenzi, Francesco; de Mora, Lee; De Nooij, Lucie; De Pedis, Daniele; De Salvo, Alessandro; De Sanctis, Umberto; De Santo, Antonella; De Vivie De Regie, Jean-Baptiste; De Zorzi, Guido; Dearnaley, William James; Debbe, Ramiro; Debenedetti, Chiara; Dechenaux, Benjamin; Dedovich, Dmitri; Degenhardt, James; Del Peso, Jose; Del Prete, Tarcisio; Delemontex, Thomas; Deliyergiyev, Maksym; Dell'Acqua, Andrea; Dell'Asta, Lidia; Della Pietra, Massimo; della Volpe, Domenico; Delmastro, Marco; Delsart, Pierre-Antoine; Deluca, Carolina; Demers, Sarah; Demichev, Mikhail; Demirkoz, Bilge; Denisov, Sergey; Derendarz, Dominik; Derkaoui, Jamal Eddine; Derue, Frederic; Dervan, Paul; Desch, Klaus Kurt; Devetak, Erik; Deviveiros, Pier-Olivier; Dewhurst, Alastair; DeWilde, Burton; Dhaliwal, Saminder; Dhullipudi, Ramasudhakar; Di Ciaccio, Anna; Di Ciaccio, Lucia; Di Donato, Camilla; Di Girolamo, Alessandro; Di Girolamo, Beniamino; Di Luise, Silvestro; Di Mattia, Alessandro; Di Micco, Biagio; Di Nardo, Roberto; Di Simone, Andrea; Di Sipio, Riccardo; Diaz, Marco Aurelio; Diehl, Edward; Dietrich, Janet; Dietzsch, Thorsten; Diglio, Sara; Dindar Yagci, Kamile; Dingfelder, Jochen; Dinut, Florin; Dionisi, Carlo; Dita, Petre; Dita, Sanda; Dittus, Fridolin; Djama, Fares; Djobava, Tamar; Barros do Vale, Maria Aline; Do Valle Wemans, André; Doan, Thi Kieu Oanh; Dobbs, Matt; Dobos, Daniel; Dobson, Ellie; Dodd, Jeremy; Doglioni, Caterina; Doherty, Tom; Doi, Yoshikuni; Dolejsi, Jiri; Dolenc, Irena; Dolezal, Zdenek; Dolgoshein, Boris; Dohmae, Takeshi; Donadelli, Marisilvia; Donini, Julien; Dopke, Jens; Doria, Alessandra; Dos Anjos, Andre; Dotti, Andrea; Dova, Maria-Teresa; Doxiadis, Alexander; Doyle, Tony; Dressnandt, Nandor; Dris, Manolis; Dubbert, Jörg; Dube, Sourabh; Duchovni, Ehud; Duckeck, Guenter; Duda, Dominik; Dudarev, Alexey; Dudziak, Fanny; Dührssen, Michael; Duerdoth, Ian; Duflot, Laurent; Dufour, Marc-Andre; Duguid, Liam; Dunford, Monica; Duran Yildiz, Hatice; Duxfield, Robert; Dwuznik, Michal; Dydak, Friedrich; Düren, Michael; Ebenstein, William; Ebke, Johannes; Eckweiler, Sebastian; Edmonds, Keith; Edson, William; Edwards, Clive; Edwards, Nicholas Charles; Ehrenfeld, Wolfgang; Eifert, Till; Eigen, Gerald; Einsweiler, Kevin; Eisenhandler, Eric; Ekelof, Tord; El Kacimi, Mohamed; Ellert, Mattias; Elles, Sabine; Ellinghaus, Frank; Ellis, Katherine; Ellis, Nicolas; Elmsheuser, Johannes; Elsing, Markus; Emeliyanov, Dmitry; Engelmann, Roderich; Engl, Albert; Epp, Brigitte; Erdmann, Johannes; Ereditato, Antonio; Eriksson, Daniel; Ernst, Jesse; Ernst, Michael; Ernwein, Jean; Errede, Deborah; Errede, Steven; Ertel, Eugen; Escalier, Marc; Esch, Hendrik; Escobar, Carlos; Espinal Curull, Xavier; Esposito, Bellisario; Etienne, Francois; Etienvre, Anne-Isabelle; Etzion, Erez; Evangelakou, Despoina; Evans, Hal; Fabbri, Laura; Fabre, Caroline; Fakhrutdinov, Rinat; Falciano, Speranza; Fang, Yaquan; Fanti, Marcello; Farbin, Amir; Farilla, Addolorata; Farley, Jason; Farooque, Trisha; Farrell, Steven; Farrington, Sinead; Farthouat, Philippe; Fassi, Farida; Fassnacht, Patrick; Fassouliotis, Dimitrios; Fatholahzadeh, Baharak; Favareto, Andrea; Fayard, Louis; Fazio, Salvatore; Febbraro, Renato; Federic, Pavol; Fedin, Oleg; Fedorko, Wojciech; Fehling-Kaschek, Mirjam; Feligioni, Lorenzo; Feng, Cunfeng; Feng, Eric; Fenyuk, Alexander; Ferencei, Jozef; Fernando, Waruna; Ferrag, Samir; Ferrando, James; Ferrara, Valentina; Ferrari, Arnaud; Ferrari, Pamela; Ferrari, Roberto; Ferreira de Lima, Danilo Enoque; Ferrer, Antonio; Ferrere, Didier; Ferretti, Claudio; Ferretto Parodi, Andrea; Fiascaris, Maria; Fiedler, Frank; Filipčič, Andrej; Filthaut, Frank; Fincke-Keeler, Margret; Fiolhais, Miguel; Fiorini, Luca; Firan, Ana; Fischer, Gordon; Fisher, Matthew; Flechl, Martin; Fleck, Ivor; Fleckner, Johanna; Fleischmann, Philipp; Fleischmann, Sebastian; Flick, Tobias; Floderus, Anders; Flores Castillo, Luis; Flowerdew, Michael; Fonseca Martin, Teresa; Formica, Andrea; Forti, Alessandra; Fortin, Dominique; Fournier, Daniel; Fowler, Andrew; Fox, Harald; Francavilla, Paolo; Franchini, Matteo; Franchino, Silvia; Francis, David; Frank, Tal; Franklin, Melissa; Franz, Sebastien; Fraternali, Marco; Fratina, Sasa; French, Sky; Friedrich, Conrad; Friedrich, Felix; Froeschl, Robert; Froidevaux, Daniel; Frost, James; Fukunaga, Chikara; Fullana Torregrosa, Esteban; Fulsom, Bryan Gregory; Fuster, Juan; Gabaldon, Carolina; Gabizon, Ofir; Gadfort, Thomas; Gadomski, Szymon; Gagliardi, Guido; Gagnon, Pauline; Galea, Cristina; Galhardo, Bruno; Gallas, Elizabeth; Gallo, Valentina Santina; Gallop, Bruce; Gallus, Petr; Gan, KK; Gao, Yongsheng; Gaponenko, Andrei; Garberson, Ford; Garcia-Sciveres, Maurice; García, Carmen; García Navarro, José Enrique; Gardner, Robert; Garelli, Nicoletta; Garitaonandia, Hegoi; Garonne, Vincent; Gatti, Claudio; Gaudio, Gabriella; Gaur, Bakul; Gauthier, Lea; Gauzzi, Paolo; Gavrilenko, Igor; Gay, Colin; Gaycken, Goetz; Gazis, Evangelos; Ge, Peng; Gecse, Zoltan; Gee, Norman; Geerts, Daniël Alphonsus Adrianus; Geich-Gimbel, Christoph; Gellerstedt, Karl; Gemme, Claudia; Gemmell, Alistair; Genest, Marie-Hélène; Gentile, Simonetta; George, Matthias; George, Simon; Gerlach, Peter; Gershon, Avi; Geweniger, Christoph; Ghazlane, Hamid; Ghodbane, Nabil; Giacobbe, Benedetto; Giagu, Stefano; Giakoumopoulou, Victoria; Giangiobbe, Vincent; Gianotti, Fabiola; Gibbard, Bruce; Gibson, Adam; Gibson, Stephen; Gilchriese, Murdock; Gillberg, Dag; Gillman, Tony; Gingrich, Douglas; Ginzburg, Jonatan; Giokaris, Nikos; Giordani, MarioPaolo; Giordano, Raffaele; Giorgi, Francesco Michelangelo; Giovannini, Paola; Giraud, Pierre-Francois; Giugni, Danilo; Giunta, Michele; Gjelsten, Børge Kile; Gladilin, Leonid; Glasman, Claudia; Glatzer, Julian; Glazov, Alexandre; Glitza, Karl-Walter; Glonti, George; Goddard, Jack Robert; Godfrey, Jennifer; Godlewski, Jan; Goebel, Martin; Göpfert, Thomas; Goeringer, Christian; Gössling, Claus; Goldfarb, Steven; Golling, Tobias; Gomes, Agostinho; Gomez Fajardo, Luz Stella; Gonçalo, Ricardo; Goncalves Pinto Firmino Da Costa, Joao; Gonella, Laura; González de la Hoz, Santiago; Gonzalez Parra, Garoe; Gonzalez Silva, Laura; Gonzalez-Sevilla, Sergio; Goodson, Jeremiah Jet; Goossens, Luc; Gorbounov, Petr Andreevich; Gordon, Howard; Gorelov, Igor; Gorfine, Grant; Gorini, Benedetto; Gorini, Edoardo; Gorišek, Andrej; Gornicki, Edward; Goshaw, Alfred; Gosselink, Martijn; Gostkin, Mikhail Ivanovitch; Gough Eschrich, Ivo; Gouighri, Mohamed; Goujdami, Driss; Goulette, Marc Phillippe; Goussiou, Anna; Goy, Corinne; Gozpinar, Serdar; Grabowska-Bold, Iwona; Grafström, Per; Grahn, Karl-Johan; Gramstad, Eirik; Grancagnolo, Francesco; Grancagnolo, Sergio; Grassi, Valerio; Gratchev, Vadim; Grau, Nathan; Gray, Heather; Gray, Julia Ann; Graziani, Enrico; Grebenyuk, Oleg; Greenshaw, Timothy; Greenwood, Zeno Dixon; Gregersen, Kristian; Gregor, Ingrid-Maria; Grenier, Philippe; Griffiths, Justin; Grigalashvili, Nugzar; Grillo, Alexander; Grinstein, Sebastian; Gris, Philippe Luc Yves; Grishkevich, Yaroslav; Grivaz, Jean-Francois; Gross, Eilam; Grosse-Knetter, Joern; Groth-Jensen, Jacob; Grybel, Kai; Guest, Daniel; Guicheney, Christophe; Guido, Elisa; Guindon, Stefan; Gul, Umar; Gunther, Jaroslav; Guo, Bin; Guo, Jun; Gutierrez, Phillip; Guttman, Nir; Gutzwiller, Olivier; Guyot, Claude; Gwenlan, Claire; Gwilliam, Carl; Haas, Andy; Haas, Stefan; Haber, Carl; Hadavand, Haleh Khani; Hadley, David; Haefner, Petra; Hahn, Ferdinand; Hajduk, Zbigniew; Hakobyan, Hrachya; Hall, David; Hamacher, Klaus; Hamal, Petr; Hamano, Kenji; Hamer, Matthias; Hamilton, Andrew; Hamilton, Samuel; Han, Liang; Hanagaki, Kazunori; Hanawa, Keita; Hance, Michael; Handel, Carsten; Hanke, Paul; Hansen, John Renner; Hansen, Jørgen Beck; Hansen, Jorn Dines; Hansen, Peter Henrik; Hansson, Per; Hara, Kazuhiko; Harenberg, Torsten; Harkusha, Siarhei; Harper, Devin; Harrington, Robert; Harris, Orin; Hartert, Jochen; Hartjes, Fred; Haruyama, Tomiyoshi; Harvey, Alex; Hasegawa, Satoshi; Hasegawa, Yoji; Hassani, Samira; Haug, Sigve; Hauschild, Michael; Hauser, Reiner; Havranek, Miroslav; Hawkes, Christopher; Hawkings, Richard John; Hawkins, Anthony David; Hayakawa, Takashi; Hayashi, Takayasu; Hayden, Daniel; Hays, Chris; Hayward, Helen; Haywood, Stephen; Head, Simon; Hedberg, Vincent; Heelan, Louise; Heim, Sarah; Heinemann, Beate; Heisterkamp, Simon; Helary, Louis; Heller, Claudio; Heller, Matthieu; Hellman, Sten; Hellmich, Dennis; Helsens, Clement; Henderson, Robert; Henke, Michael; Henrichs, Anna; Henriques Correia, Ana Maria; Henrot-Versille, Sophie; Hensel, Carsten; Henß, Tobias; Medina Hernandez, Carlos; Hernández Jiménez, Yesenia; Herrberg, Ruth; Herten, Gregor; Hertenberger, Ralf; Hervas, Luis; Hesketh, Gavin Grant; Hessey, Nigel; Higón-Rodriguez, Emilio; Hill, John; Hiller, Karl Heinz; Hillert, Sonja; Hillier, Stephen; Hinchliffe, Ian; Hines, Elizabeth; Hirose, Minoru; Hirsch, Florian; Hirschbuehl, Dominic; Hobbs, John; Hod, Noam; Hodgkinson, Mark; Hodgson, Paul; Hoecker, Andreas; Hoeferkamp, Martin; Hoffman, Julia; Hoffmann, Dirk; Hohlfeld, Marc; Holder, Martin; Holmgren, Sven-Olof; Holy, Tomas; Holzbauer, Jenny; Hong, Tae Min; Hooft van Huysduynen, Loek; Horner, Stephan; Hostachy, Jean-Yves; Hou, Suen; Hoummada, Abdeslam; Howard, Jacob; Howarth, James; Hristova, Ivana; Hrivnac, Julius; Hryn'ova, Tetiana; Hsu, Pai-hsien Jennifer; Hsu, Shih-Chieh; Hu, Diedi; Hubacek, Zdenek; Hubaut, Fabrice; Huegging, Fabian; Huettmann, Antje; Huffman, Todd Brian; Hughes, Emlyn; Hughes, Gareth; Huhtinen, Mika; Hurwitz, Martina; Huseynov, Nazim; Huston, Joey; Huth, John; Iacobucci, Giuseppe; Iakovidis, Georgios; Ibbotson, Michael; Ibragimov, Iskander; Iconomidou-Fayard, Lydia; Idarraga, John; Iengo, Paolo; Igonkina, Olga; Ikegami, Yoichi; Ikeno, Masahiro; Iliadis, Dimitrios; Ilic, Nikolina; Ince, Tayfun; Inigo-Golfin, Joaquin; Ioannou, Pavlos; Iodice, Mauro; Iordanidou, Kalliopi; Ippolito, Valerio; Irles Quiles, Adrian; Isaksson, Charlie; Ishino, Masaya; Ishitsuka, Masaki; Ishmukhametov, Renat; Issever, Cigdem; Istin, Serhat; Ivashin, Anton; Iwanski, Wieslaw; Iwasaki, Hiroyuki; Izen, Joseph; Izzo, Vincenzo; Jackson, Brett; Jackson, John; Jackson, Paul; Jaekel, Martin; Jain, Vivek; Jakobs, Karl; Jakobsen, Sune; Jakoubek, Tomas; Jakubek, Jan; Jamin, David Olivier; Jana, Dilip; Jansen, Eric; Jansen, Hendrik; Janssen, Jens; Jantsch, Andreas; Janus, Michel; Jared, Richard; Jarlskog, Göran; Jeanty, Laura; Jen-La Plante, Imai; Jennens, David; Jenni, Peter; Loevschall-Jensen, Ask Emil; Jež, Pavel; Jézéquel, Stéphane; Jha, Manoj Kumar; Ji, Haoshuang; Ji, Weina; Jia, Jiangyong; Jiang, Yi; Jimenez Belenguer, Marcos; Jin, Shan; Jinnouchi, Osamu; Joergensen, Morten Dam; Joffe, David; Johansen, Marianne; Johansson, Erik; Johansson, Per; Johnert, Sebastian; Johns, Kenneth; Jon-And, Kerstin; Jones, Graham; Jones, Roger; Jones, Tim; Joram, Christian; Jorge, Pedro; Joshi, Kiran Daniel; Jovicevic, Jelena; Jovin, Tatjana; Ju, Xiangyang; Jung, Christian; Jungst, Ralph Markus; Juranek, Vojtech; Jussel, Patrick; Juste Rozas, Aurelio; Kabana, Sonja; Kaci, Mohammed; Kaczmarska, Anna; Kadlecik, Peter; Kado, Marumi; Kagan, Harris; Kagan, Michael; Kajomovitz, Enrique; Kalinin, Sergey; Kalinovskaya, Lidia; Kama, Sami; Kanaya, Naoko; Kaneda, Michiru; Kaneti, Steven; Kanno, Takayuki; Kantserov, Vadim; Kanzaki, Junichi; Kaplan, Benjamin; Kapliy, Anton; Kaplon, Jan; Kar, Deepak; Karagounis, Michael; Karakostas, Konstantinos; Karnevskiy, Mikhail; Kartvelishvili, Vakhtang; Karyukhin, Andrey; Kashif, Lashkar; Kasieczka, Gregor; Kass, Richard; Kastanas, Alex; Kataoka, Mayuko; Kataoka, Yousuke; Katsoufis, Elias; Katzy, Judith; Kaushik, Venkatesh; Kawagoe, Kiyotomo; Kawamoto, Tatsuo; Kawamura, Gen; Kayl, Manuel; Kazama, Shingo; Kazanin, Vassili; Kazarinov, Makhail; Keeler, Richard; Keener, Paul; Kehoe, Robert; Keil, Markus; Kekelidze, George; Keller, John; Kenyon, Mike; Kepka, Oldrich; Kerschen, Nicolas; Kerševan, Borut Paul; Kersten, Susanne; Kessoku, Kohei; Keung, Justin; Khalil-zada, Farkhad; Khandanyan, Hovhannes; Khanov, Alexander; Kharchenko, Dmitri; Khodinov, Alexander; Khomich, Andrei; Khoo, Teng Jian; Khoriauli, Gia; Khoroshilov, Andrey; Khovanskiy, Valery; Khramov, Evgeniy; Khubua, Jemal; Kim, Hyeon Jin; Kim, Shinhong; Kimura, Naoki; Kind, Oliver; King, Barry; King, Matthew; King, Robert Steven Beaufoy; Kirk, Julie; Kiryunin, Andrey; Kishimoto, Tomoe; Kisielewska, Danuta; Kitamura, Takumi; Kittelmann, Thomas; Kiuchi, Kenji; Kladiva, Eduard; Klein, Max; Klein, Uta; Kleinknecht, Konrad; Klemetti, Miika; Klier, Amit; Klimek, Pawel; Klimentov, Alexei; Klingenberg, Reiner; Klinger, Joel Alexander; Klinkby, Esben; Klioutchnikova, Tatiana; Klok, Peter; Klous, Sander; Kluge, Eike-Erik; Kluge, Thomas; Kluit, Peter; Kluth, Stefan; Kneringer, Emmerich; Knoops, Edith; Knue, Andrea; Ko, Byeong Rok; Kobayashi, Tomio; Kobel, Michael; Kocian, Martin; Kodys, Peter; Köneke, Karsten; König, Adriaan; Koenig, Sebastian; Köpke, Lutz; Koetsveld, Folkert; Koevesarki, Peter; Koffas, Thomas; Koffeman, Els; Kogan, Lucy Anne; Kohlmann, Simon; Kohn, Fabian; Kohout, Zdenek; Kohriki, Takashi; Koi, Tatsumi; Kolachev, Guennady; Kolanoski, Hermann; Kolesnikov, Vladimir; Koletsou, Iro; Koll, James; Komar, Aston; Komori, Yuto; Kondo, Takahiko; Kono, Takanori; Kononov, Anatoly; Konoplich, Rostislav; Konstantinidis, Nikolaos; Kopeliansky, Revital; Koperny, Stefan; Korcyl, Krzysztof; Kordas, Kostantinos; Korn, Andreas; Korol, Aleksandr; Korolkov, Ilya; Korolkova, Elena; Korotkov, Vladislav; Kortner, Oliver; Kortner, Sandra; Kostyukhin, Vadim; Kotov, Sergey; Kotov, Vladislav; Kotwal, Ashutosh; Kourkoumelis, Christine; Kouskoura, Vasiliki; Koutsman, Alex; Kowalewski, Robert Victor; Kowalski, Tadeusz; Kozanecki, Witold; Kozhin, Anatoly; Kral, Vlastimil; Kramarenko, Viktor; Kramberger, Gregor; Krasny, Mieczyslaw Witold; Krasznahorkay, Attila; Kraus, Jana; Kreiss, Sven; Krejci, Frantisek; Kretzschmar, Jan; Krieger, Nina; Krieger, Peter; Kroeninger, Kevin; Kroha, Hubert; Kroll, Joe; Kroseberg, Juergen; Krstic, Jelena; Kruchonak, Uladzimir; Krüger, Hans; Kruker, Tobias; Krumnack, Nils; Krumshteyn, Zinovii; Kruse, Mark; Kubota, Takashi; Kuday, Sinan; Kuehn, Susanne; Kugel, Andreas; Kuhl, Thorsten; Kuhn, Dietmar; Kukhtin, Victor; Kulchitsky, Yuri; Kuleshov, Sergey; Kummer, Christian; Kuna, Marine; Kunkle, Joshua; Kupco, Alexander; Kurashige, Hisaya; Kurata, Masakazu; Kurochkin, Yurii; Kus, Vlastimil; Kuwertz, Emma Sian; Kuze, Masahiro; Kvita, Jiri; Kwee, Regina; La Rosa, Alessandro; La Rotonda, Laura; Labarga, Luis; Labbe, Julien; Lablak, Said; Lacasta, Carlos; Lacava, Francesco; Lacey, James; Lacker, Heiko; Lacour, Didier; Lacuesta, Vicente Ramón; Ladygin, Evgueni; Lafaye, Remi; Laforge, Bertrand; Lagouri, Theodota; Lai, Stanley; Laisne, Emmanuel; Lambourne, Luke; Lampen, Caleb; Lampl, Walter; Lancon, Eric; Landgraf, Ulrich; Landon, Murrough; Lang, Valerie Susanne; Lange, Clemens; Lankford, Andrew; Lanni, Francesco; Lantzsch, Kerstin; Lanza, Agostino; Laplace, Sandrine; Lapoire, Cecile; Laporte, Jean-Francois; Lari, Tommaso; Larner, Aimee; Lassnig, Mario; Laurelli, Paolo; Lavorini, Vincenzo; Lavrijsen, Wim; Laycock, Paul; Le Dortz, Olivier; Le Guirriec, Emmanuel; Le Menedeu, Eve; LeCompte, Thomas; Ledroit-Guillon, Fabienne Agnes Marie; Lee, Hurng-Chun; Lee, Jason; Lee, Shih-Chang; Lee, Lawrence; Lefebvre, Michel; Legendre, Marie; Legger, Federica; Leggett, Charles; Lehmacher, Marc; Lehmann Miotto, Giovanna; Leister, Andrew Gerard; Leite, Marco Aurelio Lisboa; Leitner, Rupert; Lellouch, Daniel; Lemmer, Boris; Lendermann, Victor; Leney, Katharine; Lenz, Tatiana; Lenzen, Georg; Lenzi, Bruno; Leonhardt, Kathrin; Leontsinis, Stefanos; Lepold, Florian; Leroy, Claude; Lessard, Jean-Raphael; Lester, Christopher; Lester, Christopher Michael; Levêque, Jessica; Levin, Daniel; Levinson, Lorne; Lewis, Adrian; Lewis, George; Leyko, Agnieszka; Leyton, Michael; Li, Bo; Li, Haifeng; Li, Ho Ling; Li, Shu; Li, Xuefei; Liang, Zhijun; Liao, Hongbo; Liberti, Barbara; Lichard, Peter; Lichtnecker, Markus; Lie, Ki; Liebig, Wolfgang; Limbach, Christian; Limosani, Antonio; Limper, Maaike; Lin, Simon; Linde, Frank; Linnemann, James; Lipeles, Elliot; Lipniacka, Anna; Liss, Tony; Lissauer, David; Lister, Alison; Litke, Alan; Liu, Chuanlei; Liu, Dong; Liu, Hao; Liu, Jianbei; Liu, Lulu; Liu, Minghui; Liu, Yanwen; Livan, Michele; Livermore, Sarah; Lleres, Annick; Llorente Merino, Javier; Lloyd, Stephen; Lobodzinska, Ewelina; Loch, Peter; Lockman, William; Loddenkoetter, Thomas; Loebinger, Fred; Loginov, Andrey; Loh, Chang Wei; Lohse, Thomas; Lohwasser, Kristin; Lokajicek, Milos; Lombardo, Vincenzo Paolo; Long, Robin Eamonn; Lopes, Lourenco; Lopez Mateos, David; Lorenz, Jeanette; Lorenzo Martinez, Narei; Losada, Marta; Loscutoff, Peter; Lo Sterzo, Francesco; Losty, Michael; Lou, XinChou; Lounis, Abdenour; Loureiro, Karina; Love, Jeremy; Love, Peter; Lowe, Andrew; Lu, Feng; Lubatti, Henry; Luci, Claudio; Lucotte, Arnaud; Ludwig, Andreas; Ludwig, Dörthe; Ludwig, Inga; Ludwig, Jens; Luehring, Frederick; Luijckx, Guy; Lukas, Wolfgang; Luminari, Lamberto; Lund, Esben; Lund-Jensen, Bengt; Lundberg, Björn; Lundberg, Johan; Lundberg, Olof; Lundquist, Johan; Lungwitz, Matthias; Lynn, David; Lytken, Else; Ma, Hong; Ma, Lian Liang; Maccarrone, Giovanni; Macchiolo, Anna; Maček, Boštjan; Machado Miguens, Joana; Macina, Daniela; Mackeprang, Rasmus; Madaras, Ronald; Maddocks, Harvey Jonathan; Mader, Wolfgang; Maenner, Reinhard; Maeno, Tadashi; Mättig, Peter; Mättig, Stefan; Magnoni, Luca; Magradze, Erekle; Mahboubi, Kambiz; Mahlstedt, Joern; Mahmoud, Sara; Mahout, Gilles; Maiani, Camilla; Maidantchik, Carmen; Maio, Amélia; Majewski, Stephanie; Makida, Yasuhiro; Makovec, Nikola; Mal, Prolay; Malaescu, Bogdan; Malecki, Pawel; Malecki, Piotr; Maleev, Victor; Malek, Fairouz; Mallik, Usha; Malon, David; Malone, Caitlin; Maltezos, Stavros; Malyshev, Vladimir; Malyukov, Sergei; Mameghani, Raphael; Mamuzic, Judita; Manabe, Atsushi; Mandelli, Luciano; Mandić, Igor; Mandrysch, Rocco; Maneira, José; Manfredini, Alessandro; Manhaes de Andrade Filho, Luciano; Manjarres Ramos, Joany Andreina; Mann, Alexander; Manning, Peter; Manousakis-Katsikakis, Arkadios; Mansoulie, Bruno; Mapelli, Alessandro; Mapelli, Livio; March, Luis; Marchand, Jean-Francois; Marchese, Fabrizio; Marchiori, Giovanni; Marcisovsky, Michal; Marino, Christopher; Marroquim, Fernando; Marshall, Zach; Martens, Kalen; Marti, Lukas Fritz; Marti-Garcia, Salvador; Martin, Brian; Martin, Brian Thomas; Martin, Jean-Pierre; Martin, Tim; Martin, Victoria Jane; Martin dit Latour, Bertrand; Martin-Haugh, Stewart; Martinez, Mario; Martinez Outschoorn, Verena; Martyniuk, Alex; Marx, Marilyn; Marzano, Francesco; Marzin, Antoine; Masetti, Lucia; Mashimo, Tetsuro; Mashinistov, Ruslan; Masik, Jiri; Maslennikov, Alexey; Massa, Ignazio; Massaro, Graziano; Massol, Nicolas; Mastrandrea, Paolo; Mastroberardino, Anna; Masubuchi, Tatsuya; Matricon, Pierre; Matsunaga, Hiroyuki; Matsushita, Takashi; Mattravers, Carly; Maurer, Julien; Maxfield, Stephen; Maximov, Dmitriy; Mayne, Anna; Mazini, Rachid; Mazur, Michael; Mazzaferro, Luca; Mazzanti, Marcello; Mc Donald, Jeffrey; Mc Kee, Shawn Patrick; McCarn, Allison; McCarthy, Robert; McCarthy, Tom; McCubbin, Norman; McFarlane, Kenneth; Mcfayden, Josh; Mchedlidze, Gvantsa; Mclaughlan, Tom; McMahon, Steve; McPherson, Robert; Meade, Andrew; Mechnich, Joerg; Mechtel, Markus; Medinnis, Mike; Meehan, Samuel; Meera-Lebbai, Razzak; Meguro, Tatsuma; Mehlhase, Sascha; Mehta, Andrew; Meier, Karlheinz; Meirose, Bernhard; Melachrinos, Constantinos; Mellado Garcia, Bruce Rafael; Meloni, Federico; Mendoza Navas, Luis; Meng, Zhaoxia; Mengarelli, Alberto; Menke, Sven; Meoni, Evelin; Mercurio, Kevin Michael; Mermod, Philippe; Merola, Leonardo; Meroni, Chiara; Merritt, Frank; Merritt, Hayes; Messina, Andrea; Metcalfe, Jessica; Mete, Alaettin Serhan; Meyer, Carsten; Meyer, Christopher; Meyer, Jean-Pierre; Meyer, Jochen; Meyer, Joerg; Michal, Sebastien; Micu, Liliana; Middleton, Robin; Migas, Sylwia; Mijović, Liza; Mikenberg, Giora; Mikestikova, Marcela; Mikuž, Marko; Miller, David; Miller, Robert; Mills, Bill; Mills, Corrinne; Milov, Alexander; Milstead, David; Milstein, Dmitry; Minaenko, Andrey; Miñano Moya, Mercedes; Minashvili, Irakli; Mincer, Allen; Mindur, Bartosz; Mineev, Mikhail; Ming, Yao; Mir, Lluisa-Maria; Mirabelli, Giovanni; Mitrevski, Jovan; Mitsou, Vasiliki A; Mitsui, Shingo; Miyagawa, Paul; Mjörnmark, Jan-Ulf; Moa, Torbjoern; Moeller, Victoria; Mönig, Klaus; Möser, Nicolas; Mohapatra, Soumya; Mohr, Wolfgang; Moles-Valls, Regina; Molfetas, Angelos; Monk, James; Monnier, Emmanuel; Montejo Berlingen, Javier; Monticelli, Fernando; Monzani, Simone; Moore, Roger; Moorhead, Gareth; Mora Herrera, Clemencia; Moraes, Arthur; Morange, Nicolas; Morel, Julien; Morello, Gianfranco; Moreno, Deywis; Moreno Llácer, María; Morettini, Paolo; Morgenstern, Marcus; Morii, Masahiro; Morley, Anthony Keith; Mornacchi, Giuseppe; Morris, John; Morvaj, Ljiljana; Moser, Hans-Guenther; Mosidze, Maia; Moss, Josh; Mount, Richard; Mountricha, Eleni; Mouraviev, Sergei; Moyse, Edward; Mueller, Felix; Mueller, James; Mueller, Klemens; Müller, Thomas; Mueller, Timo; Muenstermann, Daniel; Munwes, Yonathan; Murray, Bill; Mussche, Ido; Musto, Elisa; Myagkov, Alexey; Myska, Miroslav; Nackenhorst, Olaf; Nadal, Jordi; Nagai, Koichi; Nagai, Ryo; Nagano, Kunihiro; Nagarkar, Advait; Nagasaka, Yasushi; Nagel, Martin; Nairz, Armin Michael; Nakahama, Yu; Nakamura, Koji; Nakamura, Tomoaki; Nakano, Itsuo; Nanava, Gizo; Napier, Austin; Narayan, Rohin; Nash, Michael; Nattermann, Till; Naumann, Thomas; Navarro, Gabriela; Neal, Homer; Nechaeva, Polina; Neep, Thomas James; Negri, Andrea; Negri, Guido; Negrini, Matteo; Nektarijevic, Snezana; Nelson, Andrew; Nelson, Timothy Knight; Nemecek, Stanislav; Nemethy, Peter; Nepomuceno, Andre Asevedo; Nessi, Marzio; Neubauer, Mark; Neumann, Manuel; Neusiedl, Andrea; Neves, Ricardo; Nevski, Pavel; Newcomer, Mitchel; Newman, Paul; Nguyen Thi Hong, Van; Nickerson, Richard; Nicolaidou, Rosy; Nicquevert, Bertrand; Niedercorn, Francois; Nielsen, Jason; Nikiforou, Nikiforos; Nikiforov, Andriy; Nikolaenko, Vladimir; Nikolic-Audit, Irena; Nikolics, Katalin; Nikolopoulos, Konstantinos; Nilsen, Henrik; Nilsson, Paul; Ninomiya, Yoichi; Nisati, Aleandro; Nisius, Richard; Nobe, Takuya; Nodulman, Lawrence; Nomachi, Masaharu; Nomidis, Ioannis; Norberg, Scarlet; Nordberg, Markus; Norton, Peter; Novakova, Jana; Nozaki, Mitsuaki; Nozka, Libor; Nugent, Ian Michael; Nuncio-Quiroz, Adriana-Elizabeth; Nunes Hanninger, Guilherme; Nunnemann, Thomas; Nurse, Emily; O'Brien, Brendan Joseph; O'Neil, Dugan; O'Shea, Val; Oakes, Louise Beth; Oakham, Gerald; Oberlack, Horst; Ocariz, Jose; Ochi, Atsuhiko; Oda, Susumu; Odaka, Shigeru; Odier, Jerome; Ogren, Harold; Oh, Alexander; Oh, Seog; Ohm, Christian; Ohshima, Takayoshi; Okamura, Wataru; Okawa, Hideki; Okumura, Yasuyuki; Okuyama, Toyonobu; Olariu, Albert; Olchevski, Alexander; Olivares Pino, Sebastian Andres; Oliveira, Miguel Alfonso; Oliveira Damazio, Denis; Oliver Garcia, Elena; Olivito, Dominick; Olszewski, Andrzej; Olszowska, Jolanta; Onofre, António; Onyisi, Peter; Oram, Christopher; Oreglia, Mark; Oren, Yona; Orestano, Domizia; Orlando, Nicola; Orlov, Iliya; Oropeza Barrera, Cristina; Orr, Robert; Osculati, Bianca; Ospanov, Rustem; Osuna, Carlos; Otero y Garzon, Gustavo; Ottersbach, John; Ouchrif, Mohamed; Ouellette, Eric; Ould-Saada, Farid; Ouraou, Ahmimed; Ouyang, Qun; Ovcharova, Ana; Owen, Mark; Owen, Simon; Ozcan, Veysi Erkcan; Ozturk, Nurcan; Pacheco Pages, Andres; Padilla Aranda, Cristobal; Pagan Griso, Simone; Paganis, Efstathios; Pahl, Christoph; Paige, Frank; Pais, Preema; Pajchel, Katarina; Palacino, Gabriel; Paleari, Chiara; Palestini, Sandro; Pallin, Dominique; Palma, Alberto; Palmer, Jody; Pan, Yibin; Panagiotopoulou, Evgenia; Panduro Vazquez, William; Pani, Priscilla; Panikashvili, Natalia; Panitkin, Sergey; Pantea, Dan; Papadelis, Aras; Papadopoulou, Theodora; Paramonov, Alexander; Paredes Hernandez, Daniela; Park, Woochun; Parker, Michael Andrew; Parodi, Fabrizio; Parsons, John; Parzefall, Ulrich; Pashapour, Shabnaz; Pasqualucci, Enrico; Passaggio, Stefano; Passeri, Antonio; Pastore, Fernanda; Pastore, Francesca; Pásztor, Gabriella; Pataraia, Sophio; Patel, Nikhul; Pater, Joleen; Patricelli, Sergio; Pauly, Thilo; Pecsy, Martin; Pedraza Lopez, Sebastian; Pedraza Morales, Maria Isabel; Peleganchuk, Sergey; Pelikan, Daniel; Peng, Haiping; Penning, Bjoern; Penson, Alexander; Penwell, John; Perantoni, Marcelo; Perez, Kerstin; Perez Cavalcanti, Tiago; Perez Codina, Estel; Pérez García-Estañ, María Teresa; Perez Reale, Valeria; Perini, Laura; Pernegger, Heinz; Perrino, Roberto; Perrodo, Pascal; Peshekhonov, Vladimir; Peters, Krisztian; Petersen, Brian; Petersen, Jorgen; Petersen, Troels; Petit, Elisabeth; Petridis, Andreas; Petridou, Chariclia; Petrolo, Emilio; Petrucci, Fabrizio; Petschull, Dennis; Petteni, Michele; Pezoa, Raquel; Phan, Anna; Phillips, Peter William; Piacquadio, Giacinto; Picazio, Attilio; Piccaro, Elisa; Piccinini, Maurizio; Piec, Sebastian Marcin; Piegaia, Ricardo; Pignotti, David; Pilcher, James; Pilkington, Andrew; Pina, João Antonio; Pinamonti, Michele; Pinder, Alex; Pinfold, James; Pinto, Belmiro; Pizio, Caterina; Plamondon, Mathieu; Pleier, Marc-Andre; Plotnikova, Elena; Poblaguev, Andrei; Poddar, Sahill; Podlyski, Fabrice; Poggioli, Luc; Pohl, David-leon; Pohl, Martin; Polesello, Giacomo; Policicchio, Antonio; Polini, Alessandro; Poll, James; Polychronakos, Venetios; Pomeroy, Daniel; Pommès, Kathy; Pontecorvo, Ludovico; Pope, Bernard; Popeneciu, Gabriel Alexandru; Popovic, Dragan; Poppleton, Alan; Portell Bueso, Xavier; Pospelov, Guennady; Pospisil, Stanislav; Potrap, Igor; Potter, Christina; Potter, Christopher; Poulard, Gilbert; Poveda, Joaquin; Pozdnyakov, Valery; Prabhu, Robindra; Pralavorio, Pascal; Pranko, Aliaksandr; Prasad, Srivas; Pravahan, Rishiraj; Prell, Soeren; Pretzl, Klaus Peter; Price, Darren; Price, Joe; Price, Lawrence; Prieur, Damien; Primavera, Margherita; Prokofiev, Kirill; Prokoshin, Fedor; Protopopescu, Serban; Proudfoot, James; Prudent, Xavier; Przybycien, Mariusz; Przysiezniak, Helenka; Psoroulas, Serena; Ptacek, Elizabeth; Pueschel, Elisa; Purdham, John; Purohit, Milind; Puzo, Patrick; Pylypchenko, Yuriy; Qian, Jianming; Quadt, Arnulf; Quarrie, David; Quayle, William; Quinonez, Fernando; Raas, Marcel; Radeka, Veljko; Radescu, Voica; Radloff, Peter; Rador, Tonguc; Ragusa, Francesco; Rahal, Ghita; Rahimi, Amir; Rahm, David; Rajagopalan, Srinivasan; Rammensee, Michael; Rammes, Marcus; Randle-Conde, Aidan Sean; Randrianarivony, Koloina; Rauscher, Felix; Rave, Tobias Christian; Raymond, Michel; Read, Alexander Lincoln; Rebuzzi, Daniela; Redelbach, Andreas; Redlinger, George; Reece, Ryan; Reeves, Kendall; Reinsch, Andreas; Reisinger, Ingo; Rembser, Christoph; Ren, Zhongliang; Renaud, Adrien; Rescigno, Marco; Resconi, Silvia; Resende, Bernardo; Reznicek, Pavel; Rezvani, Reyhaneh; Richter, Robert; Richter-Was, Elzbieta; Ridel, Melissa; Rijpstra, Manouk; Rijssenbeek, Michael; Rimoldi, Adele; Rinaldi, Lorenzo; Rios, Ryan Randy; Riu, Imma; Rivoltella, Giancesare; Rizatdinova, Flera; Rizvi, Eram; Robertson, Steven; Robichaud-Veronneau, Andree; Robinson, Dave; Robinson, James; Robson, Aidan; Rocha de Lima, Jose Guilherme; Roda, Chiara; Roda Dos Santos, Denis; Roe, Adam; Roe, Shaun; Røhne, Ole; Rolli, Simona; Romaniouk, Anatoli; Romano, Marino; Romeo, Gaston; Romero Adam, Elena; Rompotis, Nikolaos; Roos, Lydia; Ros, Eduardo; Rosati, Stefano; Rosbach, Kilian; Rose, Anthony; Rose, Matthew; Rosenbaum, Gabriel; Rosenberg, Eli; Rosendahl, Peter Lundgaard; Rosenthal, Oliver; Rosselet, Laurent; Rossetti, Valerio; Rossi, Elvira; Rossi, Leonardo Paolo; Rotaru, Marina; Roth, Itamar; Rothberg, Joseph; Rousseau, David; Royon, Christophe; Rozanov, Alexandre; Rozen, Yoram; Ruan, Xifeng; Rubbo, Francesco; Rubinskiy, Igor; Ruckstuhl, Nicole; Rud, Viacheslav; Rudolph, Christian; Rudolph, Gerald; Rühr, Frederik; Ruiz-Martinez, Aranzazu; Rumyantsev, Leonid; Rurikova, Zuzana; Rusakovich, Nikolai; Ruschke, Alexander; Rutherfoord, John; Ruzicka, Pavel; Ryabov, Yury; Rybar, Martin; Rybkin, Grigori; Ryder, Nick; Saavedra, Aldo; Sadeh, Iftach; Sadrozinski, Hartmut; Sadykov, Renat; Safai Tehrani, Francesco; Sakamoto, Hiroshi; Salamanna, Giuseppe; Salamon, Andrea; Saleem, Muhammad; Salek, David; Salihagic, Denis; Salnikov, Andrei; Salt, José; Salvachua Ferrando, Belén; Salvatore, Daniela; Salvatore, Pasquale Fabrizio; Salvucci, Antonio; Salzburger, Andreas; Sampsonidis, Dimitrios; Samset, Björn Hallvard; Sanchez, Arturo; Sanchez Martinez, Victoria; Sandaker, Heidi; Sander, Heinz Georg; Sanders, Michiel; Sandhoff, Marisa; Sandoval, Tanya; Sandoval, Carlos; Sandstroem, Rikard; Sankey, Dave; Sansoni, Andrea; Santamarina Rios, Cibran; Santoni, Claudio; Santonico, Rinaldo; Santos, Helena; Santoyo Castillo, Itzebelt; Saraiva, João; Sarangi, Tapas; Sarkisyan-Grinbaum, Edward; Sarrazin, Bjorn; Sarri, Francesca; Sartisohn, Georg; Sasaki, Osamu; Sasaki, Yuichi; Sasao, Noboru; Satsounkevitch, Igor; Sauvage, Gilles; Sauvan, Emmanuel; Sauvan, Jean-Baptiste; Savard, Pierre; Savinov, Vladimir; Savu, Dan Octavian; Sawyer, Lee; Saxon, David; Saxon, James; Sbarra, Carla; Sbrizzi, Antonio; Scannicchio, Diana; Scarcella, Mark; Schaarschmidt, Jana; Schacht, Peter; Schaefer, Douglas; Schäfer, Uli; Schaelicke, Andreas; Schaepe, Steffen; Schaetzel, Sebastian; Schaffer, Arthur; Schaile, Dorothee; Schamberger, R. Dean; Schamov, Andrey; Scharf, Veit; Schegelsky, Valery; Scheirich, Daniel; Schernau, Michael; Scherzer, Max; Schiavi, Carlo; Schieck, Jochen; Schioppa, Marco; Schlenker, Stefan; Schmidt, Evelyn; Schmieden, Kristof; Schmitt, Christian; Schmitt, Sebastian; Schneider, Basil; Schnoor, Ulrike; Schoeffel, Laurent; Schoening, Andre; Schorlemmer, Andre Lukas; Schott, Matthias; Schouten, Doug; Schovancova, Jaroslava; Schram, Malachi; Schroeder, Christian; Schroer, Nicolai; Schultens, Martin Johannes; Schultes, Joachim; Schultz-Coulon, Hans-Christian; Schulz, Holger; Schumacher, Markus; Schumm, Bruce; Schune, Philippe; Schwanenberger, Christian; Schwartzman, Ariel; Schwegler, Philipp; Schwemling, Philippe; Schwienhorst, Reinhard; Schwierz, Rainer; Schwindling, Jerome; Schwindt, Thomas; Schwoerer, Maud; Sciacca, Gianfranco; Sciolla, Gabriella; Scott, Bill; Searcy, Jacob; Sedov, George; Sedykh, Evgeny; Seidel, Sally; Seiden, Abraham; Seifert, Frank; Seixas, José; Sekhniaidze, Givi; Sekula, Stephen; Selbach, Karoline Elfriede; Seliverstov, Dmitry; Sellden, Bjoern; Sellers, Graham; Seman, Michal; Semprini-Cesari, Nicola; Serfon, Cedric; Serin, Laurent; Serkin, Leonid; Seuster, Rolf; Severini, Horst; Sfyrla, Anna; Shabalina, Elizaveta; Shamim, Mansoora; Shan, Lianyou; Shank, James; Shao, Qi Tao; Shapiro, Marjorie; Shatalov, Pavel; Shaw, Kate; Sherman, Daniel; Sherwood, Peter; Shimizu, Shima; Shimojima, Makoto; Shin, Taeksu; Shiyakova, Mariya; Shmeleva, Alevtina; Shochet, Mel; Short, Daniel; Shrestha, Suyog; Shulga, Evgeny; Shupe, Michael; Sicho, Petr; Sidoti, Antonio; Siegert, Frank; Sijacki, Djordje; Silbert, Ohad; Silva, José; Silver, Yiftah; Silverstein, Daniel; Silverstein, Samuel; Simak, Vladislav; Simard, Olivier; Simic, Ljiljana; Simion, Stefan; Simioni, Eduard; Simmons, Brinick; Simoniello, Rosa; Simonyan, Margar; Sinervo, Pekka; Sinev, Nikolai; Sipica, Valentin; Siragusa, Giovanni; Sircar, Anirvan; Sisakyan, Alexei; Sivoklokov, Serguei; Sjölin, Jörgen; Sjursen, Therese; Skinnari, Louise Anastasia; Skottowe, Hugh Philip; Skovpen, Kirill; Skubic, Patrick; Slater, Mark; Slavicek, Tomas; Sliwa, Krzysztof; Smakhtin, Vladimir; Smart, Ben; Smestad, Lillian; Smirnov, Sergei; Smirnov, Yury; Smirnova, Lidia; Smirnova, Oxana; Smith, Ben Campbell; Smith, Douglas; Smith, Kenway; Smizanska, Maria; Smolek, Karel; Snesarev, Andrei; Snow, Steve; Snow, Joel; Snyder, Scott; Sobie, Randall; Sodomka, Jaromir; Soffer, Abner; Solans, Carlos; Solar, Michael; Solc, Jaroslav; Soldatov, Evgeny; Soldevila, Urmila; Solfaroli Camillocci, Elena; Solodkov, Alexander; Solovyanov, Oleg; Solovyev, Victor; Soni, Nitesh; Sopko, Vit; Sopko, Bruno; Sosebee, Mark; Soualah, Rachik; Soukharev, Andrey; Spagnolo, Stefania; Spanò, Francesco; Spighi, Roberto; Spigo, Giancarlo; Spiwoks, Ralf; Spousta, Martin; Spreitzer, Teresa; Spurlock, Barry; St Denis, Richard Dante; Stahlman, Jonathan; Stamen, Rainer; Stanecka, Ewa; Stanek, Robert; Stanescu, Cristian; Stanescu-Bellu, Madalina; Stanitzki, Marcel Michael; Stapnes, Steinar; Starchenko, Evgeny; Stark, Jan; Staroba, Pavel; Starovoitov, Pavel; Staszewski, Rafal; Staude, Arnold; Stavina, Pavel; Steele, Genevieve; Steinbach, Peter; Steinberg, Peter; Stekl, Ivan; Stelzer, Bernd; Stelzer, Harald Joerg; Stelzer-Chilton, Oliver; Stenzel, Hasko; Stern, Sebastian; Stewart, Graeme; Stillings, Jan Andre; Stockton, Mark; Stoerig, Kathrin; Stoicea, Gabriel; Stonjek, Stefan; Strachota, Pavel; Stradling, Alden; Straessner, Arno; Strandberg, Jonas; Strandberg, Sara; Strandlie, Are; Strang, Michael; Strauss, Emanuel; Strauss, Michael; Strizenec, Pavol; Ströhmer, Raimund; Strom, David; Strong, John; Stroynowski, Ryszard; Stugu, Bjarne; Stumer, Iuliu; Stupak, John; Sturm, Philipp; Styles, Nicholas Adam; Soh, Dart-yin; Su, Dong; Subramania, Halasya Siva; Subramaniam, Rajivalochan; Succurro, Antonella; Sugaya, Yorihito; Suhr, Chad; Suk, Michal; Sulin, Vladimir; Sultansoy, Saleh; Sumida, Toshi; Sun, Xiaohu; Sundermann, Jan Erik; Suruliz, Kerim; Susinno, Giancarlo; Sutton, Mark; Suzuki, Yu; Suzuki, Yuta; Svatos, Michal; Swedish, Stephen; Sykora, Ivan; Sykora, Tomas; Sánchez, Javier; Ta, Duc; Tackmann, Kerstin; Taffard, Anyes; Tafirout, Reda; Taiblum, Nimrod; Takahashi, Yuta; Takai, Helio; Takashima, Ryuichi; Takeda, Hiroshi; Takeshita, Tohru; Takubo, Yosuke; Talby, Mossadek; Talyshev, Alexey; Tamsett, Matthew; Tan, Kong Guan; Tanaka, Junichi; Tanaka, Reisaburo; Tanaka, Satoshi; Tanaka, Shuji; Tanasijczuk, Andres Jorge; Tani, Kazutoshi; Tannoury, Nancy; Tapprogge, Stefan; Tardif, Dominique; Tarem, Shlomit; Tarrade, Fabien; Tartarelli, Giuseppe Francesco; Tas, Petr; Tasevsky, Marek; Tassi, Enrico; Tayalati, Yahya; Taylor, Christopher; Taylor, Frank; Taylor, Geoffrey; Taylor, Wendy; Teinturier, Marthe; Teischinger, Florian Alfred; Teixeira Dias Castanheira, Matilde; Teixeira-Dias, Pedro; Temming, Kim Katrin; Ten Kate, Herman; Teng, Ping-Kun; Terada, Susumu; Terashi, Koji; Terron, Juan; Testa, Marianna; Teuscher, Richard; Therhaag, Jan; Theveneaux-Pelzer, Timothée; Thoma, Sascha; Thomas, Juergen; Thompson, Emily; Thompson, Paul; Thompson, Peter; Thompson, Stan; Thomsen, Lotte Ansgaard; Thomson, Evelyn; Thomson, Mark; Thong, Wai Meng; Thun, Rudolf; Tian, Feng; Tibbetts, Mark James; Tic, Tomáš; Tikhomirov, Vladimir; Tikhonov, Yury; Timoshenko, Sergey; Tiouchichine, Elodie; Tipton, Paul; Tisserant, Sylvain; Todorov, Theodore; Todorova-Nova, Sharka; Toggerson, Brokk; Tojo, Junji; Tokár, Stanislav; Tokushuku, Katsuo; Tollefson, Kirsten; Tomoto, Makoto; Tompkins, Lauren; Toms, Konstantin; Tonoyan, Arshak; Topfel, Cyril; Topilin, Nikolai; Torrence, Eric; Torres, Heberth; Torró Pastor, Emma; Toth, Jozsef; Touchard, Francois; Tovey, Daniel; Trefzger, Thomas; Tremblet, Louis; Tricoli, Alesandro; Trigger, Isabel Marian; Trincaz-Duvoid, Sophie; Tripiana, Martin; Triplett, Nathan; Trischuk, William; Trocmé, Benjamin; Troncon, Clara; Trottier-McDonald, Michel; True, Patrick; Trzebinski, Maciej; Trzupek, Adam; Tsarouchas, Charilaos; Tseng, Jeffrey; Tsiakiris, Menelaos; Tsiareshka, Pavel; Tsionou, Dimitra; Tsipolitis, Georgios; Tsiskaridze, Shota; Tsiskaridze, Vakhtang; Tskhadadze, Edisher; Tsukerman, Ilya; Tsulaia, Vakhtang; Tsung, Jieh-Wen; Tsuno, Soshi; Tsybychev, Dmitri; Tua, Alan; Tudorache, Alexandra; Tudorache, Valentina; Tuggle, Joseph; Turala, Michal; Turecek, Daniel; Turk Cakir, Ilkay; Turlay, Emmanuel; Turra, Ruggero; Tuts, Michael; Tykhonov, Andrii; Tylmad, Maja; Tyndel, Mike; Tzanakos, George; Uchida, Kirika; Ueda, Ikuo; Ueno, Ryuichi; Ugland, Maren; Uhlenbrock, Mathias; Uhrmacher, Michael; Ukegawa, Fumihiko; Unal, Guillaume; Undrus, Alexander; Unel, Gokhan; Unno, Yoshinobu; Urbaniec, Dustin; Urquijo, Phillip; Usai, Giulio; Uslenghi, Massimiliano; Vacavant, Laurent; Vacek, Vaclav; Vachon, Brigitte; Vahsen, Sven; Valenta, Jan; Valentinetti, Sara; Valero, Alberto; Valkar, Stefan; Valladolid Gallego, Eva; Vallecorsa, Sofia; Valls Ferrer, Juan Antonio; Van Berg, Richard; Van Der Deijl, Pieter; van der Geer, Rogier; van der Graaf, Harry; Van Der Leeuw, Robin; van der Poel, Egge; van der Ster, Daniel; van Eldik, Niels; van Gemmeren, Peter; van Vulpen, Ivo; Vanadia, Marco; Vandelli, Wainer; Vaniachine, Alexandre; Vankov, Peter; Vannucci, Francois; Vari, Riccardo; Varnes, Erich; Varol, Tulin; Varouchas, Dimitris; Vartapetian, Armen; Varvell, Kevin; Vassilakopoulos, Vassilios; Vazeille, Francois; Vazquez Schroeder, Tamara; Vegni, Guido; Veillet, Jean-Jacques; Veloso, Filipe; Veness, Raymond; Veneziano, Stefano; Ventura, Andrea; Ventura, Daniel; Venturi, Manuela; Venturi, Nicola; Vercesi, Valerio; Verducci, Monica; Verkerke, Wouter; Vermeulen, Jos; Vest, Anja; Vetterli, Michel; Vichou, Irene; Vickey, Trevor; Vickey Boeriu, Oana Elena; Viehhauser, Georg; Viel, Simon; Villa, Mauro; Villaplana Perez, Miguel; Vilucchi, Elisabetta; Vincter, Manuella; Vinek, Elisabeth; Vinogradov, Vladimir; Virchaux, Marc; Virzi, Joseph; Vitells, Ofer; Viti, Michele; Vivarelli, Iacopo; Vives Vaque, Francesc; Vlachos, Sotirios; Vladoiu, Dan; Vlasak, Michal; Vogel, Adrian; Vokac, Petr; Volpi, Guido; Volpi, Matteo; Volpini, Giovanni; von der Schmitt, Hans; von Radziewski, Holger; von Toerne, Eckhard; Vorobel, Vit; Vorwerk, Volker; Vos, Marcel; Voss, Rudiger; Vossebeld, Joost; Vranjes, Nenad; Vranjes Milosavljevic, Marija; Vrba, Vaclav; Vreeswijk, Marcel; Vu Anh, Tuan; Vuillermet, Raphael; Vukotic, Ilija; Wagner, Wolfgang; Wagner, Peter; Wahlen, Helmut; Wahrmund, Sebastian; Wakabayashi, Jun; Walch, Shannon; Walder, James; Walker, Rodney; Walkowiak, Wolfgang; Wall, Richard; Waller, Peter; Walsh, Brian; Wang, Chiho; Wang, Haichen; Wang, Hulin; Wang, Jike; Wang, Jin; Wang, Rui; Wang, Song-Ming; Wang, Tan; Warburton, Andreas; Ward, Patricia; Wardrope, David Robert; Warsinsky, Markus; Washbrook, Andrew; Wasicki, Christoph; Watanabe, Ippei; Watkins, Peter; Watson, Alan; Watson, Ian; Watson, Miriam; Watts, Gordon; Watts, Stephen; Waugh, Anthony; Waugh, Ben; Weber, Michele; Weber, Pavel; Webster, Jordan S; Weidberg, Anthony; Weigell, Philipp; Weingarten, Jens; Weiser, Christian; Wells, Phillippa; Wenaus, Torre; Wendland, Dennis; Weng, Zhili; Wengler, Thorsten; Wenig, Siegfried; Wermes, Norbert; Werner, Matthias; Werner, Per; Werth, Michael; Wessels, Martin; Wetter, Jeffrey; Weydert, Carole; Whalen, Kathleen; White, Andrew; White, Martin; White, Sebastian; Whitehead, Samuel Robert; Whiteson, Daniel; Whittington, Denver; Wicek, Francois; Wicke, Daniel; Wickens, Fred; Wiedenmann, Werner; Wielers, Monika; Wienemann, Peter; Wiglesworth, Craig; Wiik-Fuchs, Liv Antje Mari; Wijeratne, Peter Alexander; Wildauer, Andreas; Wildt, Martin Andre; Wilhelm, Ivan; Wilkens, Henric George; Will, Jonas Zacharias; Williams, Eric; Williams, Hugh; Willis, William; Willocq, Stephane; Wilson, John; Wilson, Michael Galante; Wilson, Alan; Wingerter-Seez, Isabelle; Winkelmann, Stefan; Winklmeier, Frank; Wittgen, Matthias; Wollstadt, Simon Jakob; Wolter, Marcin Wladyslaw; Wolters, Helmut; Wong, Wei-Cheng; Wooden, Gemma; Wosiek, Barbara; Wotschack, Jorg; Woudstra, Martin; Wozniak, Krzysztof; Wraight, Kenneth; Wright, Michael; Wrona, Bozydar; Wu, Sau Lan; Wu, Xin; Wu, Yusheng; Wulf, Evan; Wynne, Benjamin; Xella, Stefania; Xiao, Meng; Xie, Song; Xu, Chao; Xu, Da; Xu, Lailin; Yabsley, Bruce; Yacoob, Sahal; Yamada, Miho; Yamaguchi, Hiroshi; Yamamoto, Akira; Yamamoto, Kyoko; Yamamoto, Shimpei; Yamamura, Taiki; Yamanaka, Takashi; Yamazaki, Takayuki; Yamazaki, Yuji; Yan, Zhen; Yang, Haijun; Yang, Un-Ki; Yang, Yi; Yang, Zhaoyu; Yanush, Serguei; Yao, Liwen; Yao, Yushu; Yasu, Yoshiji; Ybeles Smit, Gabriel Valentijn; Ye, Jingbo; Ye, Shuwei; Yilmaz, Metin; Yoosoofmiya, Reza; Yorita, Kohei; Yoshida, Rikutaro; Yoshihara, Keisuke; Young, Charles; Young, Christopher John; Youssef, Saul; Yu, Dantong; Yu, Jaehoon; Yu, Jie; Yuan, Li; Yurkewicz, Adam; Zabinski, Bartlomiej; Zaidan, Remi; Zaitsev, Alexander; Zajacova, Zuzana; Zanello, Lucia; Zanzi, Daniele; Zaytsev, Alexander; Zeitnitz, Christian; Zeman, Martin; Zemla, Andrzej; Zendler, Carolin; Zenin, Oleg; Ženiš, Tibor; Zinonos, Zinonas; Zenz, Seth; Zerwas, Dirk; Zevi della Porta, Giovanni; Zhang, Dongliang; Zhang, Huaqiao; Zhang, Jinlong; Zhang, Xueyao; Zhang, Zhiqing; Zhao, Long; Zhao, Zhengguo; Zhemchugov, Alexey; Zhong, Jiahang; Zhou, Bing; Zhou, Ning; Zhou, Yue; Zhu, Cheng Guang; Zhu, Hongbo; Zhu, Junjie; Zhu, Yingchun; Zhuang, Xuai; Zhuravlov, Vadym; Zibell, Andre; Zieminska, Daria; Zimin, Nikolai; Zimmermann, Robert; Zimmermann, Simone; Zimmermann, Stephanie; Ziolkowski, Michael; Zitoun, Robert; Živković, Lidija; Zmouchko, Viatcheslav; Zobernig, Georg; Zoccoli, Antonio; zur Nedden, Martin; Zutshi, Vishnu; Zwalinski, Lukasz

2013-07-17

This paper presents a summary of beam-induced backgrounds observed in the ATLAS detector and discusses methods to tag and remove background contaminated events in data. Trigger-rate based monitoring of beam-related backgrounds is presented. The correlations of backgrounds with machine conditions, such as residual pressure in the beam-pipe, are discussed. Results from dedicated beam-background simulations are shown, and their qualitative agreement with data is evaluated. Data taken during the passage of unpaired, i.e. non-colliding, proton bunches is used to obtain background-enriched data samples. These are used to identify characteristic features of beam-induced backgrounds, which then are exploited to develop dedicated background tagging tools. These tools, based on observables in the Pixel detector, the muon spectrometer and the calorimeters, are described in detail and their efficiencies are evaluated. Finally an example of an application of these techniques to a monojet analysis is given, which demonstra...

Gamma Interferon-Induced Guanylate Binding Protein 1 Is a Novel Actin Cytoskeleton Remodeling Factor

OpenAIRE

Ostler, Nicole; Britzen-Laurent, Nathalie; Liebl, Andrea; Naschberger, Elisabeth; Lochnit, Günter; Ostler, Markus; Forster, Florian; Kunzelmann, Peter; Ince, Semra; Supper, Verena; Praefcke, Gerrit J. K.; Schubert, Dirk W.; Stockinger, Hannes; Herrmann, Christian; Stürzl, Michael

2014-01-01

Gamma interferon (IFN-γ) regulates immune defenses against viruses, intracellular pathogens, and tumors by modulating cell proliferation, migration, invasion, and vesicle trafficking processes. The large GTPase guanylate binding protein 1 (GBP-1) is among the cellular proteins that is the most abundantly induced by IFN-γ and mediates its cell biologic effects. As yet, the molecular mechanisms of action of GBP-1 remain unknown. Applying an interaction proteomics approach, we identified actin a...

GammaLog Playback 1.0 - mobile gamma ray spectrometry software

International Nuclear Information System (INIS)

Watson, R.J.; Smethurst, M.A.

2011-01-01

The Geological Survey of Norway (NGU) operates a mobile gamma ray spectrometer system which can be used in nuclear emergency situations to determine the location and type of orphan sources, or the extent and type of fallout contamination. The system consists of a 20 litre (16 litre downward and 4 litre upward looking) RSX-5 NaI detector and spectrometer, and can be mounted in fixed wing aircraft, helicopters, or vans/cars as appropriate. NGU has developed its own data acquisition and analysis software for this system. GammaLog (Smethurst 2005) controls the acquisition, display, and storage of data from the spectrometer, and performs real-time data analysis including estimation of dose rates and fallout concentrations, and separation of geological and anthropogenic components of the signal. The latter is particularly important where the geological radioisotope signal varies strongly from one place to another, and makes it easier to locate and identify anthropogenic sources which might otherwise be difficult to separate from the geological background signal. A modified version of GammaLog has been developed, GammaLog Playback, which allows the replay of previously acquired GammaLog datasets, while performing similar processing and display as the GammaLog acquisition software. This allows datasets to be reviewed and compared in the field or during post-survey analysis to help plan subsequent measurement strategies.(Au)

Lunar occultations for gamma-ray source measurements

Science.gov (United States)

Koch, David G.; Hughes, E. B.; Nolan, Patrick L.

1990-01-01

The unambiguous association of discrete gamma-ray sources with objects radiating at other wavelengths, the separation of discrete sources from the extended emission within the Galaxy, the mapping of gamma-ray emission from nearby galaxies and the measurement of structure within a discrete source cannot presently be accomplished at gamma-ray energies. In the past, the detection processes used in high-energy gamma-ray astronomy have not allowed for good angular resolution. This problem can be overcome by placing gamma-ray detectors on the moon and using the horizon as an occulting edge to achieve arcsec resolution. For purposes of discussion, this concept is examined for gamma rays above 100 MeV for which pair production dominates the detection process and locally-generated nuclear gamma rays do not contribute to the background.

gamma. -ray. Present status and problems

Energy Technology Data Exchange (ETDEWEB)

Okudaira, K [Rikkyo Univ., Tokyo (Japan). Faculty of Science

1975-01-01

As ..gamma..-ray advances straightly through space, the study on cosmic ..gamma..-ray will give the information concerning the origin directly. However, the intensity is weak, and the avoidance of background is a serious problem. The wide-spread components were studied by OSO-3. The intensity of the galactic disc component around 100 MeV was reported as (3.4+-1.0)x10/sup -5/ photons (cm/sup 2/, radian, sec)/sup -1/ by OSO-3 and 0.2x10/sup -4/ photons (cm/sup 2/, radian sec)/sup -1/ by SAS-2, and corresponds to the calculated ..gamma.. yield from ..pi../sup 0/. The strong disc component, so-called galactic center region, has been observed, and is due to the mixture of ..gamma..-ray from ..pi../sup 0/ and inverse Compton ..gamma..-ray. A peak at 476+-24 KeV was found as well as the continuous component. Special care must be taken for the observation of isotropic component, since it is hardly distinguished from the background. It is considered that the isotropic component is due to the inverse Compton scattering of 3/sup 0/K radiation in super-galactic space and the contribution from outer galaxy. The nearest point source of ..gamma..-ray is the sun. Among the other point sources, the crab nebula is the most reliable one. The energy flux of pulse component showed the spectrum of E/sup -1/. ..gamma..-ray bursts were observed by man-made satellites Vela-5 and 6. Theoretical explanation is still incomplete regarding the bursts. (Kato, T.).

Quantitative comparison between experimental and simulated gamma-ray spectra induced by 14 MeV tagged neutrons

Energy Technology Data Exchange (ETDEWEB)

Perot, B., E-mail: bertrand.perot@cea.fr [CEA, DEN, Cadarache, Nuclear Measurement Laboratory, F-13108 Saint-Paul-lez-Durance (France); El Kanawati, W.; Carasco, C.; Eleon, C. [CEA, DEN, Cadarache, Nuclear Measurement Laboratory, F-13108 Saint-Paul-lez-Durance (France); Valkovic, V. [A.C.T.d.o.o., Prilesje 4, 10000 Zagreb (Croatia); Sudac, D.; Obhodas, J. [Ruder Boskovic Institute, Bijenicka c. 54, 10000 Zagreb (Croatia); Sannie, G. [CEA, LIST, Saclay, F-91191 Gif-sur-Yvette (France)

2012-07-15

Fast neutron interrogation with the associated particle technique can be used to identify explosives in cargo containers (EURITRACK FP6 project) and unexploded ordnance on the seabed (UNCOSS FP7 project), by detecting gamma radiations induced by 14 MeV neutrons produced in the {sup 2}H({sup 3}H,{alpha})n reaction. The origin of the gamma rays can be determined in 3D by the detection of the alpha particle, which provides the direction of the opposite neutron and its time-of-flight. Gamma spectroscopy provides the relative counts of carbon, nitrogen, and oxygen, which are converted to chemical fractions to differentiate explosives from other organic substances. To this aim, Monte Carlo calculations are used to take into account neutron moderation and gamma attenuation in cargo materials or seawater. This paper presents an experimental verification that C, N, and O counts are correctly reproduced by numerical simulation. A quantitative comparison is also reported for silicon, iron, lead, and aluminium. - Highlights: Black-Right-Pointing-Pointer Gamma-ray spectra produced by 14 MeV neutrons in C, N, O, Si, Al, Fe, and Pb elements. Black-Right-Pointing-Pointer Quantitative comparison with MCNPX simulations using the ENDF/B-VII.0 library. Black-Right-Pointing-Pointer C, N, and O counts correctly reproduced and chemical proportions recovered using calculation. Black-Right-Pointing-Pointer Application to the detection of explosives or illicit drugs in cargo containers.

Production of gamma induced reactive oxygen species and damage of DNA molecule in HaCaT cells under euoxic and hypoxic condition

International Nuclear Information System (INIS)

Joseph, P.; Bhat, N.N.; Copplestone, D.; Narayana, Y.

2014-01-01

The paper deals with the study of gamma radiation induced reactive oxygen species (ROS) generation in normal human keratinocytes (HaCaT) cells and quantification of subsequent damages induced on DNA molecules. The DNA damages induced in cells after gamma irradiation has been analyzed using Alkaline comet assay. The ROS produced in the cells were quantified by measuring fluorescence after loading the cells with 2', 7' dichlorofluorescin diacetate, a dye that is oxidized into a highly fluorescent form in the presence of peroxides. Studies reveal that in HaCaT cells radical generation occurs when exposed to ionizing radiation and it increases with dose. The induced DNA damages also increases with dose and ROS generation. The study clearly shows the importance of ROS in DNA damage induction and the cells possessing elevated levels of DNA damage after radiation exposure is due to the effect of increased levels of intracellular ROS. (author)

Fluorine determination in human and animal bones by particle-induced gamma-ray emission

International Nuclear Information System (INIS)

Sastri, Chaturvedula S.; Hoffmann, Peter; Ortner, Hugo M.; Iyengar, Venkatesh; Blondiaux, Gilbert; Tessier, Yves; Petri, Hermann; Aras, Namik K.; Zaichick, Vladimir

2002-01-01

Fluorine was determined in the iliac crest bones of patients and in ribs collected from postmortem investigations by particle-induced gamma-ray emission based on the 19 F(p,pγ) 19 F reaction, using 20/2.5 MeV protons. The results indicate that for 68% of the human samples the F concentration is in the range 500-1999 μg g -1 . For comparison purposes fluorine was also determined in some animal bones; in some animal tissues lateral profiles of fluorine were measured. (abstract)

Gamma-ray induced Doppler broadening and the determination of lifetimes of excited nuclear states

International Nuclear Information System (INIS)

Boerner, H.G.; Jolie, J.; Robinson, S.J.; Kessler, E.G.; Dewey, S.M.; Greene, G.; Deslattes, R.; Ulbig, S.; Lieb, K.P.; Casten, R.F.; Krusche, B.; Cizewski, J.A.

1990-01-01

Measurements of lifetimes of excited states in nuclei yield crucial information for sensitive tests of nuclear models. Here a novel method will be discussed which involves the GRID (Gamma Ray Induced Doppler broadening) technique, in which Doppler broadening is observed in a transition from a nucleus recoiling from the emission of a previous gamma ray. As the recoil energy is extremely small, ultra-high energy resolving power has to be used. To date all such experiments have been carried out at ILL using the GAMS4 double flat crystal spectrometer which is operated in a NIST-ILL collaboration. The method can be used for all lifetimes below a few picoseconds. The wide range of applicability, together with the very exhaustive set of data often obtained, is an advantage with respect to many other methods. The characteristic features of GRID will be discussed using some selected examples. 21 refs., 8 figs

Gamma radiation induced mutant for improved yield components in sunflower

International Nuclear Information System (INIS)

Elangovan, M.

2001-01-01

Sunflower has become an important oilseed in the Indian vegetable oil pool following its introduction from Russia in 1969. It can be used for all quality products useful to humans. The need for genetic variability and new useful gene sources has necessitated that sunflower breeders and geneticists utilize a wide range of germplasm in their breeding programmes. The induction of mutations in sunflower by physical and chemical mutagens has been practiced quite intensively in the last two decades. The results recorded to date suggest that utilization of mutagenesis could be a great advantage in improving the sunflower crop. An induced mutation programme was undertaken to generate variability in the variety 'Morden' using gamma rays. The certified and genetically pure seeds were irradiated with 50, 100, and 150 Gy gamma rays and used for further studies. Selection in M 2 generations, raised from different treatments, revealed the presence of an erectophylly leaf mutant from 50 Gy treatment. The isolated mutant showed improved yield components like head diameter, 100- seed weight and yield per plant. The mutant was a plant with short petiole length and erect leaves. This type of leaf get sunlight throughout the day. From morning to afternoon, the first half of the leaf gets sunlight, and from afternoon to evening the second half of the leaf gets sunlight. As a result of getting sunlight the whole day, the plant had more photosynthetic products and grew vigorously. Plant height, head diameter and 100-seed weight had direct effect on seed yield, and the number of leaves and stem diameter influenced the seed yield indirectly. In the M 3 generation, the mutant showed an almost two-fold increase over the parent variety for all investigated characters, except that of the yield per plant where there was a three-fold increase. The present investigation has shown that there are remarkable possibilities of increasing the yield components in sunflower by induced mutations

Ionizing/displacement synergistic effects induced by gamma and neutron irradiation in gate-controlled lateral PNP bipolar transistors

Energy Technology Data Exchange (ETDEWEB)

Wang, Chenhui, E-mail: wangchenhui@nint.ac.cn [State Key Laboratory of Intense Pulsed Irradiation Simulation and Effect, Northwest Institute of Nuclear Technology, P.O. Box 69-10, Xi’an 710024 (China); Chen, Wei; Yao, Zhibin; Jin, Xiaoming; Liu, Yan; Yang, Shanchao [State Key Laboratory of Intense Pulsed Irradiation Simulation and Effect, Northwest Institute of Nuclear Technology, P.O. Box 69-10, Xi’an 710024 (China); Wang, Zhikuan [State Key Laboratory of Analog Integrated Circuit, Chongqing 400060 (China)

2016-09-21

A kind of gate-controlled lateral PNP bipolar transistor has been specially designed to do experimental validations and studies on the ionizing/displacement synergistic effects in the lateral PNP bipolar transistor. The individual and mixed irradiation experiments of gamma rays and neutrons are accomplished on the transistors. The common emitter current gain, gate sweep characteristics and sub-threshold sweep characteristics are measured after each exposure. The results indicate that under the sequential irradiation of gamma rays and neutrons, the response of the gate-controlled lateral PNP bipolar transistor does exhibit ionizing/displacement synergistic effects and base current degradation is more severe than the simple artificial sum of those under the individual gamma and neutron irradiation. Enough attention should be paid to this phenomenon in radiation damage evaluation. - Highlights: • A kind of gate-controlled lateral PNP bipolar transistor has been specially designed to facilitate the analysis of ionizing/displacement synergistic effects induced by the mixed irradiation of gamma and neutron. • The difference between ionizing/displacement synergistic effects and the simple sum of TID and displacement effects is analyzed. • The physical mechanisms of synergistic effects are explained.

THE ORIGIN OF GAMMA RAYS FROM GLOBULAR CLUSTERS

International Nuclear Information System (INIS)

Cheng, K. S.; Chernyshov, D. O.; Dogiel, V. A.; Hui, C. Y.; Kong, A. K. H.

2010-01-01

Fermi has detected gamma-ray emission from eight globular clusters (GCs). It is commonly believed that the energy sources of these gamma rays are millisecond pulsars (MSPs) inside GCs. Also it has been standard to explain the spectra of most Fermi Large Area Telescope pulsars including MSPs resulting from the curvature radiation (CR) of relativistic electrons/positrons inside the pulsar magnetosphere. Therefore, gamma rays from GCs are expected to be the collection of CR from all MSPs inside the clusters. However, the angular resolution is not high enough to pinpoint the nature of the emission. In this paper, we calculate the gamma rays produced by the inverse Compton (IC) scattering between relativistic electrons/positrons in the pulsar wind of MSPs in the GCs and background soft photons including cosmic microwave/relic photons, background star lights in the clusters, the galactic infrared photons, and the galactic star lights. We show that the gamma-ray spectrum from 47 Tucanae can be explained equally well by upward scattering of either the relic photons, the galactic infrared photons, or the galactic star lights, whereas the gamma-ray spectra from the other seven GCs are best fitted by the upward scattering of either the galactic infrared photons or the galactic star lights. We also find that the observed gamma-ray luminosity is correlated better with the combined factor of the encounter rate and the background soft photon energy density. Therefore, the IC scattering may also contribute to the observed gamma-ray emission from GCs detected by Fermi in addition to the standard CR process. Furthermore, we find that the emission region of high-energy photons from GCs produced by the IC scattering is substantially larger than the cores of GCs with a radius >10 pc. The diffuse radio and X-rays emitted from GCs can also be produced by the synchrotron radiation and IC scattering, respectively. We suggest that future observations including radio, X-rays, and gamma rays

Induced chlorophyll variation in pineapple c v. 'queen' by gamma irradiation (60Cobalt)

International Nuclear Information System (INIS)

Valencia, Lolita DC.

2012-01-01

Irradiation using gamma rays ( 60 Cobalt) coupled with in vitro culture techniques was undertaken to induce variation or mutation in pineapple. Calli from crown meristem tips of pineapple cv 'Queen' [Ananas comosus (L.) Merr.] were initiated using Murashiege and Skoog's basal meduim supplemented with 10mg/liter 4-amino-3,5,6-trichloro-2-pyrodinecarboxylic acid (Picloram). High percentage of growth and shoot proliferation was observed in basal medium supplemented with 50 μM benzene adenine purine (BAP) and 10 μM gibberrelic acid (GA) after 8 weeks in vitro. Regenerants derived from shoots using different doses of gamma rays (0, 5, 10, 15, 20, 25 and 30 Gy) were evaluated under laboratory conditions. Of the different doses, 15 Gy produced the most variegation in young shoots (chlorophyll variants) maintained in vitro. The variants appeared to have yellow and green color combinations of the young leaves of pineapple 'Queen' variety. When transplanted inside the greenhouse, high percentage of plantlets survival was observed, ranging from 90-95%. Of the different irradiation doses, variegation in young leaves was observed at 15, 20, 25 and 30 Gy. Further assessment on the effect of irradiation is currently being unertaken under screen house conditions. The variants produced could serve a basis for selection of ornamental-type pineapple. In addition, protocols developed on the use of in vitro culture techniques could be utilized as a tool for induced mutation breeding in pineapple. (author)

Action of the chlorophyllin on the genetic damage induced by gamma radiation in germinal cells of Drosophila Melanogaster; Accion de la clorofilina sobre el dano genetico inducido por radiacion gamma en celulas germinales de Drosophila Melanogaster

Energy Technology Data Exchange (ETDEWEB)

Cruces, M.P.; Pimentel, A.E.; Moreno, A.; Moreno, R. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

2003-07-01

The obtained results using somatic cells, they have evidenced that the chlorophyllin (CHLN) it can act inhibiting or increasing the damage caused by different mutagens. The objective of this investigation is to evaluate the effect of the CHLN on the damage induced by gamma radiation in germinal cells of Drosophila. Two tests were used, the lost of the X chromosome and the conventional test of lethal recessive bound to the sex (LRLS); both with a system of litters. The obtained results in both essays, indicated that the CHLN doesn't reduce the damage induced by the gamma radiation in none of the cellular monitored states. (Author)

Action of the chlorophyllin on the genetic damage induced by gamma radiation in germinal cells of Drosophila Melanogaster; Accion de la clorofilina sobre el dano genetico inducido por radiacion gamma en celulas germinales de Drosophila Melanogaster

Energy Technology Data Exchange (ETDEWEB)

Cruces, M P; Pimentel, A E; Moreno, A; Moreno, R [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

2003-07-01

The obtained results using somatic cells, they have evidenced that the chlorophyllin (CHLN) it can act inhibiting or increasing the damage caused by different mutagens. The objective of this investigation is to evaluate the effect of the CHLN on the damage induced by gamma radiation in germinal cells of Drosophila. Two tests were used, the lost of the X chromosome and the conventional test of lethal recessive bound to the sex (LRLS); both with a system of litters. The obtained results in both essays, indicated that the CHLN doesn't reduce the damage induced by the gamma radiation in none of the cellular monitored states. (Author)

Simultaneous beta and gamma spectroscopy

Science.gov (United States)

Farsoni, Abdollah T.; Hamby, David M.

2010-03-23

A phoswich radiation detector for simultaneous spectroscopy of beta rays and gamma rays includes three scintillators with different decay time characteristics. Two of the three scintillators are used for beta detection and the third scintillator is used for gamma detection. A pulse induced by an interaction of radiation with the detector is digitally analyzed to classify the type of event as beta, gamma, or unknown. A pulse is classified as a beta event if the pulse originated from just the first scintillator alone or from just the first and the second scintillator. A pulse from just the third scintillator is recorded as gamma event. Other pulses are rejected as unknown events.

Suitable gamma ray dose determination in order to induce genetic variation in kaboli chickpea (Cicer Arietinum L)

International Nuclear Information System (INIS)

Naserian Khiabani, B.; Ahari Mostafavi, H.; Fathollahi, H.; Vedadi, S.; Mosavi Shalmani, M. A.

2008-01-01

In spite of chickpea's use in Iran and its ability of being replaced to adjust the shortage of protein in dietary habits, yield production is very low. One of the main reasons for chickpea's low yield production is its sensitiveness to some diseases, pest and environmental stresses. Genetic variation in chickpea is very low, because of its self pollination. In breeding programs, genetic variation plays an essential role so that the induction of genetic variation in plant population is very important for the plant breeders. The induced mutation through different kinds of mutagens is one of the important ways of genetic variation. In this research, first the sensitiveness of four cultivars (ILC.486, Philip86, Bivinich, Jam) were assessed to different gamma ray doses (100, 200, 300, 400 Gy). The results showed that with an increase in gamma ray dose, the growth rate of chickpea's genotypes decreases. In this respect, the decrease of growth rate has a linear relationship with the gamma ray dose and it is independent from the genotypes. The root length is more sensitive to gamma ray doses than its shoot, and it was observed that at the low doses the root growth decreases, comparing to the shoot growth. On the other hand, in high doses of gamma ray growth abrasion (Ageotropism, Albinism and etc.) were observed. Some traits variation (such as leaf shape, leaf size, leaf color, Albinism, etc.) were seen in M 2 generation, and finally to continue the project, three doses of gamma ray (150,200,250) were selected for the next year

Development of a Reference Database for Particle Induced Gamma Ray Emission (PIGE) Spectroscopy

International Nuclear Information System (INIS)

2017-09-01

Ion beam analysis techniques are non-destructive analytical techniques used to identify the composition and structure of surface layers of materials. The applications of these techniques span environmental control, cultural heritage and conservation, materials and fusion technologies. The particle-induced gamma-ray emission (PIGE) spectroscopy technique in particular, is a powerful tool for detecting light elements in certain depths of surface layers. This publication describes the coordinated effort to measure and compile cross section data relevant to PIGE analysis and make these data available to the community of practice through a comprehensive online database.

Energy–angle correlation of neutrons and gamma-rays emitted from an HEU source

Energy Technology Data Exchange (ETDEWEB)

Miloshevsky, G., E-mail: gennady@purdue.edu; Hassanein, A.

2014-06-01

Special Nuclear Materials (SNM) yield very unique fission signatures, namely correlated neutrons and gamma-rays. A major challenge is not only to detect, but also to rapidly identify and recognize SNM with certainty. Accounting for particle multiplicity and correlations is one of standard ways to detect SNM. However, many parameter data such as joint distributions of energy, angle, lifetime, and multiplicity of neutrons and gamma-rays can lead to better recognition of SNM signatures in the background radiation noise. These joint distributions are not well understood. The Monte Carlo simulations of the transport of neutrons and gamma-rays produced from spontaneous and interrogation-induced fission of SNM are carried out using the developed MONSOL computer code. The energy spectra of neutrons and gamma-rays from a bare Highly Enriched Uranium (HEU) source are investigated. The energy spectrum of gamma-rays shows spectral lines by which HEU isotopes can be identified, while those of neutrons do not show any characteristic lines. The joint probability density function (JPDF) of the energy–angle association of neutrons and gamma-rays is constructed. Marginal probability density functions (MPDFs) of energy and angle are derived from JPDF. A probabilistic model is developed for the analysis of JPDF and MPDFs. This probabilistic model is used to evaluate mean values, standard deviations, covariance and correlation between the energy and angle of neutrons and gamma-rays emitted from the HEU source. For both neutrons and gamma-rays, it is found that the energy–angle variables are only weakly correlated.

Gamma ray induced chromophore modification of softwood thermomechanical pulp

International Nuclear Information System (INIS)

Robert, S.; Daneault, C.; Viel, C.; Lepine, F.

1992-01-01

This study focuses on bleaching a softwood (black spruce, balsam fur) thermomechanical pulp with gamma rays. Gamma rays are known for their enormous penetrating power, along with their ionizing properties. They can generate highly energetic radicals capable of oxidizing lignin chromophores. The authors studied the influence of isopropyl alcohol, sodium borohydride, oxygen, hydrogen peroxide, nitrogen dioxide and water along with gamma ray irradiation of the pulps. The authors measured the optimal dose and dose rate, along with the influence of the radical scavengers like oxygen on the bleaching effect of gamma irradiated pulps. They observe various degrees of bleaching of these pulps. Evidence relates this bleaching to the generation of perhydroxyl anions upon irradiation of water. Also, they were able to pinpoint the influence of the dose rate on the rate of formation and disappearance of these perhydroxyl anions and their influence on bleaching kinetics. Stability toward photoyellowing, and photoyellowing's kinetic of papers from these pulps was also studied

Effects of background radiation

International Nuclear Information System (INIS)

Knox, E.G.; Stewart, A.M.; Gilman, E.A.; Kneale, G.W.

1987-01-01

The primary objective of this investigation is to measure the relationship between exposure to different levels of background gamma radiation in different parts of the country, and different Relative Risks for leukaemias and cancers in children. The investigation is linked to an earlier analysis of the effects of prenatal medical x-rays upon leukaemia and cancer risk; the prior hypothesis on which the background-study was based, is derived from the earlier results. In a third analysis, the authors attempted to measure varying potency of medical x-rays delivered at different stages of gestation and the results supply a link between the other two estimates. (author)

Comparison of backgrounds in OSO-7 and SMM spectrometers and short-term activation in SMM

Science.gov (United States)

Dunphy, P. P.; Forrest, D. J.; Chupp, E. L.; Share, G. H.

1989-01-01

The backgrounds in the OSO-7 Gamma-Ray Monitor and the Solar Maximum Mission Gamma-Ray Spectrometer are compared. After scaling to the same volume, the background spectra agree to within 30 percent. This shows that analyses which successfully describe the background in one detector can be applied to similar detectors of different sizes and on different platforms. The background produced in the SMM spectrometer by a single trapped-radiation belt passage is also studied. This background is found to be dominated by a positron-annihilation line and a continuum spectrum with a high energy cutoff at 5 MeV.

Measurement of Background Gamma Radiation Levels at Two ...

African Journals Online (AJOL)

MICHAEL

ABSTRACT: An in-situ measurement of the background radiation level was carried out at the vicinity of three ... Soil contains small quantities of radioactive elements along with their progeny. .... assessment for soil samples from Kestanbol.

Gamma ray, EMS and sodium azide induced effectiveness and efficiency of chlorophyll mutations in basmati rice (Oryza sativa L.)

International Nuclear Information System (INIS)

Singh, Sanjeev; Singh, J.; Singh, R.K.

2001-01-01

The effectiveness and efficiency of gamma ray, EMS, sodium azide alone or in combination in relation to chlorophyll mutations in two varieties of Basmati rice (Oryza sativa L.) in M 2 generation were studied. The chlorophyll mutations were induced by all the doses of mutagens alone or in combination relatively at a fair frequency in both the varieties in M 2 generation. In general, it was found that combination treatments of gamma rays and EMS were observed to be more efficient in Taraori Basmati, while EMS alone and combination treatment of gamma rays and EMS were more efficient in Pusa Basmati 1 on sterility and growth injury basis both. Sodium azide at 0.5 mM was found as the most effective dose in both Taraori Basmati and Pusa Basmati 1 cultivars. (author)

Effect of dose of gamma-rays and ethylmethane sulphonate on the germination and survival of induced mutations in pigeonpea

Energy Technology Data Exchange (ETDEWEB)

Premsekar, S [Central Inst. for Cotton Research, Coimbatore (India). Regional Station; Appadurai, R [Tamil Nadu Agricultural Univ., Coimbatore (India)

1981-06-01

The LD/sub 50/ values for germination and survival of the induced mutants (M/sub 1/) of pigeonpea (Cajanus cajan (Linn.) Millsp.) were attained with 20 and 15 krad when gamma-rays were used, and 30 and 40 mM concentration when EMS was used. In the combination treatments the half-kill dose for germination and survival was reached even at the low dose combination of 5 krad gamma-ray + 20 mM EMS. Higher doses resulted in lower pollen and seed fertility. The sterility was much enhanced in the combined treatments. The number of pods, seed yield and weight of seeds could be stimulated with 10 and 15 krad doses of gamma-rays and 20 mM of EMS. In combination treatments such a stimulatory effect was noticed in seed weight only.

Inclusive Search for the Higgs Boson in the $H \\to \\gamma\\gamma$ Channel

CERN Document Server

Pieri, Marco; Fisk, Ian; Letts, James; Litvin, V; Branson, James G

2006-01-01

We have carried out a detailed study of the inclusive search for the Higgs boson in the H->gamma gamma channel with the CMS detector at LHC. The analysis is based on full Monte Carlo simulation. Though for the moment we have only simulated data to work with, we have designed an analysis that can determine the background from real data and will thus only depend on signal Monte Carlo when data will be available. This largely reduces the systematic error and, together with the excellent energy resolution of the CMS electromagnetic calorimeter, enables a search that would otherwise be very difficult because of the large amount of expected background. We have studied both a standard cut-based search and a more optimized analysis that takes advantage of the wide range of signal/background expectations as function of the possible selection cuts. Since discovery in this channel is expected to take one or more years of LHC running, such optimized analyses should be studied to minimize the time to discovery and to assu...

Evaluation of gamma radiation induced genetic damage in the fish Cyprinus carpio using comet assay

International Nuclear Information System (INIS)

Praveen Kumar, M.K.; Shyama, S.K.; Bhagat, S.S.; Chaubey, R.C.

2013-01-01

Radionuclides released from various sources including the industries, as well as, accidental release during a nuclear disaster can contaminate inland water bodies. Suitable bio-monitoring methods/biomarkers are the need of the day to assess the impact of high/low levels of radiation exposure in aquatic environment. Fishes are very important as a group of ecologically and commercially important non-human biota and are often used as a bioindicators of aquatic pollution. Present work was carried out to assess the genotoxic effect of gamma radiation on fresh water fish Cyprinus carpio (common carp) in vivo using comet assay. Fishes were irradiated with 2, 4, 6, 8 and 10 Gy of gamma rays using a teletherapy machine and comet assay was performed on nucleated erythrocytes after 24, 48 and 72 h of irradiation . A significant increase in % tail DNA was observed at all the doses of gamma radiation as compared to controls indicating radiation induced DNA damage in a dose-dependent manner. Maximum % tail DNA was observed at 24 h which gradually declined till 72 h, in a time-dependent manner. This decrease in damage may indicate repair of the damaged DNA and or loss of heavily damaged cells, over a period of time. The study reveals that the comet assay may be used as a sensitive and rapid method to detect genotoxicity of gamma radiation and other environmental pollutants in sentinel species. (author)

A gamma-gamma coincidence/anticoincidence spectrometer for low-level cosmogenic (22)Na/(7)Be activity ratio measurement.

Science.gov (United States)

Zhang, Weihua; Ungar, Kurt; Stukel, Matthew; Mekarski, Pawel

2014-04-01

In this study, a digital gamma-gamma coincidence/anticoincidence spectrometer was developed and examined for low-level cosmogenic (22)Na and (7)Be in air-filter sample monitoring. The spectrometer consists of two bismuth germanate scintillators (BGO) and an XIA LLC Digital Gamma Finder (DGF)/Pixie-4 software and card package. The spectrometer design allows a more selective measurement of (22)Na with a significant background reduction by gamma-gamma coincidence events processing. Hence, the system provides a more sensitive way to quantify trace amounts of (22)Na than normal high resolution gamma spectrometry providing a critical limit of 3 mBq within a 20 h count. The use of a list-mode data acquisition technique enabled simultaneous determination of (22)Na and (7)Be activity concentrations using a single measurement by coincidence and anticoincidence mode respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

Simulated and measured neutron/gamma light output distribution for poly-energetic neutron/gamma sources

Science.gov (United States)

Hosseini, S. A.; Zangian, M.; Aghabozorgi, S.

2018-03-01

In the present paper, the light output distribution due to poly-energetic neutron/gamma (neutron or gamma) source was calculated using the developed MCNPX-ESUT-PE (MCNPX-Energy engineering of Sharif University of Technology-Poly Energetic version) computational code. The simulation of light output distribution includes the modeling of the particle transport, the calculation of scintillation photons induced by charged particles, simulation of the scintillation photon transport and considering the light resolution obtained from the experiment. The developed computational code is able to simulate the light output distribution due to any neutron/gamma source. In the experimental step of the present study, the neutron-gamma discrimination based on the light output distribution was performed using the zero crossing method. As a case study, 241Am-9Be source was considered and the simulated and measured neutron/gamma light output distributions were compared. There is an acceptable agreement between the discriminated neutron/gamma light output distributions obtained from the simulation and experiment.

Fc gamma receptor activation induces the tyrosine phosphorylation of both phospholipase C (PLC)-gamma 1 and PLC-gamma 2 in natural killer cells

OpenAIRE

1992-01-01

Crosslinking of the low affinity immunoglobulin G (IgG) Fc receptor (Fc gamma R type III) on natural killer (NK) cells initiates antibody- dependent cellular cytotoxicity. During this process, Fc gamma R stimulation results in the rapid activation of phospholipase C (PLC), which hydrolyzes membrane phosphoinositides, generating inositol-1,4,5- trisphosphate and sn-1,2-diacylglycerol as second messengers. We have recently reported that PLC activation after Fc gamma R stimulation can be inhibit...

Distinguishing 'Higgs' spin hypotheses using $\\gamma \\gamma$ and $W W^*$ decays

CERN Document Server

Ellis, John; Hwang, Dae Sung; Sanz, Veronica; You, Tevong

2013-01-01

The new particle X recently discovered by the ATLAS and CMS Collaborations in searches for the Higgs boson has been observed to decay into gamma gamma, ZZ* and WW*, but its spin and parity, J^P, remain a mystery, with J^P = 0^+ and 2^+ being open possibilities. We use PYTHIA and Delphes to simulate an analysis of the angular distribution of gg to X to gamma gamma decays in a full 2012 data set, including realistic background levels. We show that this angular distribution should provide strong discrimination between the possibilities of spin zero and spin two with graviton-like couplings: ~ 3 sigma if a conservative symmetric interpretation of the log-likelihood ratio (LLR) test statistic is used, and ~ 6 sigma if a less conservative asymmetric interpretation is used. The WW and ZZ couplings of the Standard Model Higgs boson and of a 2^+ particle with graviton-like couplings are both expected to exhibit custodial symmetry. We simulate the present ATLAS and CMS search strategies for X to WW* using PYTHIA and De...

A new measurement of the $K^{\\pm} \\rightarrow \\pi^{\\pm} \\gamma \\gamma$ decay at the NA48/2 experiment

CERN Document Server

Batley, J.R.; Lazzeroni, C.; Munday, D.J.; Slater, M.W.; Wotton, S.A.; Arcidiacono, R.; Bocquet, G.; Cabibbo, N.; Ceccucci, A.; Cundy, D.; Falaleev, V.; Fidecaro, M.; Gatignon, L.; Gonidec, A.; Kubischta, W.; Norton, A.; Maier, A.; Patel, M.; Peters, A.; Balev, S.; Frabetti, P.L.; Gersabeck, E.; Goudzovski, E.; Hristov, P.; Kekelidze, V.; Kozhuharov, V.; Litov, L.; Madigozhin, D.; Molokanova, N.; Polenkevich, I.; Potrebenikov, Yu.; Stoynev, S.; Zinchenko, A.; Monnier, E.; Swallow, E.; Winston, R.; Rubin, P.; Walker, A.; Baldini, W.; Cotta Ramusino, A.; Dalpiaz, P.; Damiani, C.; Fiorini, M.; Gianoli, A.; Martini, M.; Petrucci, F.; Savrie, M.; Scarpa, M.; Wahl, H.; Bizzeti, A.; Lenti, M.; Veltri, M.; Calvetti, M.; Celeghini, E.; Iacopini, E.; Ruggiero, G.; Behler, M.; Eppard, K.; Kleinknecht, K.; Marouelli, P.; Masetti, L.; Moosbrugger, U.; Morales Morales, C.; Renk, B.; Wache, M.; Wanke, R.; Winhart, A.; Coward, D.; Dabrowski, A.; Fonseca Martin, T.; Shieh, M.; Szleper, M.; Velasco, M.; Wood, M.D.; Cenci, P.; Pepe, M.; Petrucci, M.C.; Anzivino, G.; Imbergamo, E.; Nappi, A.; Piccini, M.; Raggi, M.; Valdata-Nappi, M.; Cerri, C.; Fantechi, R.; Collazuol, G.; DiLella, L.; Lamanna, G.; Mannelli, I.; Michetti, A.; Costantini, F.; Doble, N.; Fiorini, L.; Giudici, S.; Pierazzini, G.; Sozzi, M.; Venditti, S.; Bloch-Devaux, B.; Cheshkov, C.; Cheze, J.B.; De Beer, M.; Derre, J.; Marel, G.; Mazzucato, E.; Peyaud, B.; Vallage, B.; Holder, M.; Ziolkowski, M.; Biino, C.; Cartiglia, N.; Marchetto, F.; Bifani, S.; Clemencic, M.; Goy Lopez, S.; Dibon, H.; Jeitler, M.; Markytan, M.; Mikulec, I.; Neuhofer, G.; Widhalm, L.

2014-01-01

The NA48/2 experiment at CERN collected two data samples with minimum bias trigger conditions in 2003 and 2004. A measurement of the rate and dynamic properties of the rare decay $K^\\pm\\to\\pi^\\pm\\gamma\\gamma$ from these data sets based on 149 decay candidates with an estimated background of $15.5\\pm0.7$ events is reported. The model-independent branching ratio in the kinematic range $z=(m_{\\gamma\\gamma}/m_K)^2>0.2$ is measured to be ${\\cal B}_{\\rm MI}(z>0.2) = (0.877 \\pm 0.089) \\times 10^{-6}$, and the branching ratio in the full kinematic range assuming a particular Chiral Perturbation Theory description to be ${\\cal B}(K_{\\pi\\gamma\\gamma}) = (0.910 \\pm 0.075) \\times 10^{-6}$.

Environmental gamma radiation monitoring at Visakhapatnam using thermoluminescence dosimeters

International Nuclear Information System (INIS)

Swarnkar, M.; Sahu, S.K.; Takale, R.A.; Shetty, P.G.; Pundit, G.G.; Puranik, V.D.

2012-01-01

The gamma rays are the most significant part of environmental dose due to its large range and deep penetrating power. The environmental gamma radiation is mainly originated from two sources natural radiation and artificially produced radiation. The natural radiation dose arises from the cosmic radiation (galactic and solar) and from the Earth (terrestrial) surface. In the last few decades there is a growing concern all over the world about radiation and their exposure to population. Thus it is necessary to conduct radiological environmental surveillance. The radiation survey data are useful to establish the natural background gamma radiation levels. Extensive gamma radiation survey was carried out around the surroundings of Vishakhapatnam using Thermoluminescence Dosimeters (TLDs). The CaSO 4 :(0.2 mole %) Dy Teflon TLD discs, specifically designed for environmental gamma radiation monitoring purpose were used. These TLD badge are having very high TL sensitivity, a negligible fading rate and a stable TL response. TLDs were deployed on quarterly basis for two years to obtain the cumulative gamma background radiation levels in the study area. The radiological survey was also carried out by using a calibrated radiation survey meter. The annual dose rates were computed from quarterly values actually found and normalised to 365 days. The environmental gamma radiation levels around Vishakhapatnam were found to be in the range of 0.79 mGy/y to 1.86 mGy/y. It is clearly seen from the results that location to location there is a large variation in external gamma radiation levels. During the cycle of the TLD survey, spot readings of the background radiation levels were taken, both while placing the TLDs and while removing them. The instantaneous dose rates measured using survey meter, are also following the large variation as found in TLDs. It varies between 110 nGy/hr to 210 nGy/hr. (author)

Modeling background radiation using geochemical data: A case study in and around Cameron, Arizona.

Science.gov (United States)

Marsac, Kara E; Burnley, Pamela C; Adcock, Christopher T; Haber, Daniel A; Malchow, Russell L; Hausrath, Elisabeth M

2016-12-01

This study compares high resolution forward models of natural gamma-ray background with that measured by high resolution aerial gamma-ray surveys. The ability to predict variations in natural background radiation levels should prove useful for those engaged in measuring anthropogenic contributions to background radiation for the purpose of emergency response and homeland security operations. The forward models are based on geologic maps and remote sensing multi-spectral imagery combined with two different sources of data: 1) bedrock geochemical data (uranium, potassium and thorium concentrations) collected from national databases, the scientific literature and private companies, and 2) the low spatial resolution NURE (National Uranium Resource Evaluation) aerial gamma-ray survey. The study area near Cameron, Arizona, is located in an arid region with minimal vegetation and, due to the presence of abandoned uranium mines, was the subject of a previous high resolution gamma-ray survey. We found that, in general, geologic map units form a good basis for predicting the geographic distribution of the gamma-ray background. Predictions of background gamma-radiation levels based on bedrock geochemical analyses were not as successful as those based on the NURE aerial survey data sorted by geologic unit. The less successful result of the bedrock geochemical model is most likely due to a number of factors including the need to take into account the evolution of soil geochemistry during chemical weathering and the influence of aeolian addition. Refinements to the forward models were made using ASTER visualizations to create subunits of similar exposure rate within the Chinle Formation, which contains multiple lithologies and by grouping alluvial units by drainage basin rather than age. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Induced protein polymorphisms and nutritional quality of gamma irradiation mutants of sorghum

Energy Technology Data Exchange (ETDEWEB)

Mehlo, Luke, E-mail: LMehlo@csir.co.za [CSIR Biosciences, Meiring Naude Road, P.O. Box 395, Pretoria 0001 (South Africa); Mbambo, Zodwa [CSIR Biosciences, Meiring Naude Road, P.O. Box 395, Pretoria 0001 (South Africa); Microbiology Discipline, School of Life Sciences, University of KwaZulu-Natal (Westville Campus), Private Bag X54001, Durban 4000 (South Africa); Bado, Souleymane [Plant Breeding and Genetics Laboratory – Joint FAO/IAEA Agriculture and Biotechnology Laboratory, International Atomic Energy Agency Laboratories, A-2444 Seibersdorf (Austria); Lin, Johnson [Microbiology Discipline, School of Life Sciences, University of KwaZulu-Natal (Westville Campus), Private Bag X54001, Durban 4000 (South Africa); Moagi, Sydwell M.; Buthelezi, Sindisiwe; Stoychev, Stoyan; Chikwamba, Rachel [CSIR Biosciences, Meiring Naude Road, P.O. Box 395, Pretoria 0001 (South Africa)

2013-09-15

Highlights: • We analyse kafirin protein polymorphisms induced by gamma irradiation in sorghum. • One mutant with suppressed kafirins in the endosperm accumulated them in the germ. • Kafirin polymorphisms were associated with high levels of free amino acids. • Nutritional value of sorghum can be improved significantly by induced mutations. - Abstract: Physical and biochemical analysis of protein polymorphisms in seed storage proteins of a mutant population of sorghum revealed a mutant with redirected accumulation of kafirin proteins in the germ. The change in storage proteins was accompanied by an unusually high level accumulation of free lysine and other essential amino acids in the endosperm. This mutant further displayed a significant suppression in the synthesis and accumulation of the 27 kDa γ-, 24 kDa α-A1 and the 22 kDa α-A2 kafirins in the endosperm. The suppression of kafirins was counteracted by an upsurge in the synthesis and accumulation of albumins, globulins and other proteins. The data collectively suggest that sorghum has huge genetic potential for nutritional biofortification and that induced mutations can be used as an effective tool in achieving premium nutrition in staple cereals.

Induced protein polymorphisms and nutritional quality of gamma irradiation mutants of sorghum

International Nuclear Information System (INIS)

Mehlo, Luke; Mbambo, Zodwa; Bado, Souleymane; Lin, Johnson; Moagi, Sydwell M.; Buthelezi, Sindisiwe; Stoychev, Stoyan; Chikwamba, Rachel

2013-01-01

Highlights: • We analyse kafirin protein polymorphisms induced by gamma irradiation in sorghum. • One mutant with suppressed kafirins in the endosperm accumulated them in the germ. • Kafirin polymorphisms were associated with high levels of free amino acids. • Nutritional value of sorghum can be improved significantly by induced mutations. - Abstract: Physical and biochemical analysis of protein polymorphisms in seed storage proteins of a mutant population of sorghum revealed a mutant with redirected accumulation of kafirin proteins in the germ. The change in storage proteins was accompanied by an unusually high level accumulation of free lysine and other essential amino acids in the endosperm. This mutant further displayed a significant suppression in the synthesis and accumulation of the 27 kDa γ-, 24 kDa α-A1 and the 22 kDa α-A2 kafirins in the endosperm. The suppression of kafirins was counteracted by an upsurge in the synthesis and accumulation of albumins, globulins and other proteins. The data collectively suggest that sorghum has huge genetic potential for nutritional biofortification and that induced mutations can be used as an effective tool in achieving premium nutrition in staple cereals

Background simulation for the GENIUS project

International Nuclear Information System (INIS)

Ponkratenko, O.A.; Tretyak, V.I.; Zdesenko, Yu.G.

1999-01-01

The background simulations for the GENIUS experiment were performed with the help of GEANT 3.21 package and event generator DECAY 4.Contributions from the cosmogenic activity produced in the Ge detectors and from its radioactive impurities as well as from contamination of the liquid nitrogen and other materials were calculated.External gamma and neutron background were taking into consideration also.The results of calculations evidently show feasibility of the GENIUS project,which can substantially promote development of modern astroparticle physics

Degradation of polycarbonate induced by gamma radiation

International Nuclear Information System (INIS)

Araujo, E.S. de; Guedes, S.M.L.

1992-01-01

Polycarbonate (PC) DUROLON amorphous, of molecular weight 22000 g/mol is used in medical supplies and may be sterilized by gamma radiation. The main chain scission and polymer degradation occur when this polymer is irradiated. The value G = 1.54 to DUROLON was obtained by equation: 10 6 /M v = 10 6 /M v' + 0.054 G R. The degradation without crosslinking it is not general rule to all types of polycarbonates; an comparison was realized. The infrared (FT-IR) spectra of irradiated PC by gamma rays with different doses showed the main chain scissions in carbonyl groups. The mechanism of polymeric degradation to DUROLON, observed by NMR spectra, is a recombination of phenoxy and phenyl radicals. (author)

Induced resistance to hydrogen peroxide, UV and gamma radiation in bacillus species

International Nuclear Information System (INIS)

Bashandy, A.S.

2005-01-01

The catalase activity produced in four bacillus spp.(bacillus cereus, B. laterosporus, B. pumilus and B. subtilis (Escherichia coli was used for comparison) was measured and the sensitivity of these bacteria to hydrogen peroxide was tested. Bacillus spp. had higher resistance to hydrogen peroxide than E. coil. cultures of bacillus spp . When pretreated with sublethal level of hydrogen peroxide, became relatively resistant to the lethal effects of hydrogen than untreated control cultures. These pretreated cells were also resistant to lethality mediated by UV light and gamma radiation. The obtained results suggest that bacillus spp. Possess inducible defense mechanism (s) against the deleterious effects of oxidants and /or ionizing radiation

QCD jet simulation with CMS at LHC and background studies to H to gamma gamma process

CERN Document Server

Litvin, V; Shevchenko, S; Wisniewski, N

2002-01-01

We have simulated and reconstructed one million of QCD jet events. This study was done with CMS full detector simulation, based on GEANT3 package, and object-oriented CMS C++ reconstruction program. The understanding of QCD jet background is important for the Higgs search in two-photon decay mode. The comparison with other types of backgrounds was also done. It was shown that the isolation tools were important ones to isolate the signal process from the huge background one. Using the isolation criteria based on the information from PbWO /sub 4/ electromagnetic calorimeter and the tracker we were able to reduce the QCD jet background to 15% of the total one. (9 refs).

Modulatory role of ginger on some physiological and histological changes in female rats induced by gamma radiation and/or fat

International Nuclear Information System (INIS)

Ali, S.E.

2007-01-01

The objective of this study was to determine the potential benefits of ginger against the radiation and fat hazards in female rats. This study was carried out on 42 female albino rats (100-120 g) exposed to shot dose of gamma radiation (4.5 Gy) and/or feeding on diet contain 20% fat then treated with 2% ginger solution. The results showed that ginger minimized the physiological disorders (clotting time, cholesterol, Na + , K + , lipid peroxide and progesterone hormone) induced by gamma irradiation and/or fat. The histological examination revealed that exposure to gamma radiation or fat supplementation caused vacuolar epithelial lining of renal tubules and interstitial hemorrhage with fibrosis in kidney. Ginger treatment minimized the histological changes in kidney and lung

Study of the Possible Effects of Combined Therapy of Vitamin E with Certain Anti osteoporotic Agents on Changes Induced in Gamma-Irradiated Female Rats

International Nuclear Information System (INIS)

Heba Mohamed Atef Mostafa Gheita

2015-01-01

Whole body gamma irradiation (total dose 15 Gy / week for 5 weeks) induced bone injury in rats manifested as histopathological alterations confirmed by certain biochemical changes including urinary calcium, phosphorous and hydroxyproline, serum osteocalcin, oxidative stress bio markers, as well as pain perception. Vitamin E was effective by virtue of its antioxidant activity. Although, olive oil was studied as a vehicle for vitamin E, it could ameliorate the bone injury produced by gamma irradiation. Calcitonin and clodronate each alone was effective in retarding the bone injury induced by gamma-irradiation. Combination of calcitonin or clodronate with vitamin E showed better results than each of them alone. Serum osteocalcin of the irradiated rats was unaffected by vitamin E, olive oil, calcitonin or clodronate while combination of vitamin E with either calcitonin or clodronate was showed significant effects.

Method and apparatus for neutron induced gamma ray logging for lithology identification

International Nuclear Information System (INIS)

Oliver, D.W.; Culver, R.B.

1981-01-01

The patent describes a neutron-gamma well logging technique which can distinguish between sandstone and limestone formations irrespective of water salinity in the formation. The formation surrounding a borehole is irradiated by fast neutrons and the resulting gamma rays are counted. The gamma rays are converted to electrical signals in three distinct steps; the first two signals result from gamma rays associated with calcium content of the formation and the third signal from gamma rays associated with silicon content. Gamma rays resulting from irradiation of calcium are counted at two non-contiguous energy bands. (O.T.)