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Cosmic Radiation

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https://www.readbyqxmd.com/read/28074016/cari-7a-development-and-validation
#1
Kyle Copeland
Aircrew members can be exposed to higher annual doses of natural ionizing radiation than members of the general population in most parts of the world. The principal ionizing radiation to which they are exposed is galactic cosmic radiation (GCR). Among the particles present in the primary spectrum are heavy ions: relativistic nuclei of lithium and heavier elements. These ions have very high radiation weighting factors and can contribute significantly to the effective dose at altitudes above the Pfotzer maximum...
January 10, 2017: Radiation Protection Dosimetry
https://www.readbyqxmd.com/read/28040602/investigation-of-cosmic-ray-induced-background-of-germanium-gamma-spectrometer-using-geant4-simulation
#2
Nguyen Quoc Hung, Vo Hong Hai, Masaharu Nomachi
In this article, a GEANT4 Monte Carlo simulation toolkit was used to study the response of the cosmic-ray induced background on a High-Purity Germanium (HPGe) gamma spectrometer in the wide energy range, up to 100MeV. The natural radiation background measurements of the spectrometer were carried out in the energy region from 0.04 to 50MeV. The simulated cosmic-ray induced background of the Ge detector was evaluated in comparison with the measured data. The contribution of various cosmic-ray components including muons, neutrons, protons, electrons, positrons and photons was investigated...
December 28, 2016: Applied Radiation and Isotopes
https://www.readbyqxmd.com/read/28034510/a-second-generation-low-background-gamma-ray-spectrometer
#3
Richard M Lindstrom
For the ultimate sensitivity in trace radiochemical analysis, the radiation detector must have high efficiency and low background. A low-background gamma-ray spectrometer in regular use at NIST for over twenty years is being supplemented by a new system, improved in several ways. The new detector is much larger, a shield of iron reduces cosmic neutron background compared with lead, large plastic scintillators reduce the muon continuum background, and a digital data acquisition system gives new opportunities for optimization...
December 21, 2016: Applied Radiation and Isotopes
https://www.readbyqxmd.com/read/28027166/ncrp-vision-for-the-future-and-program-area-committee-activities
#4
John D Boice
The National Council on Radiation Protection and Measurements (NCRP) believes that the most critical need for the nation in radiation protection is to train, engage, and retain radiation professionals for the future. Not only is the pipeline shrinking, but for some areas there is no longer a pipe! When the call comes to respond, there may be no one to answer the phone! The NCRP "Where are the Radiation Professionals?" initiative, Council Committee (CC) 2, and this year's annual meeting are to focus our efforts to find solutions and not just reiterate the problems...
February 2017: Health Physics
https://www.readbyqxmd.com/read/27993190/investigation-on-contribution-of-neutron-monitor-data-to-estimation-of-aviation-doses
#5
M Kákona, O Ploc, D Kyselová, J Kubančák, R Langer, K Kudela
Recently, many efforts have appeared to routinely measure radiation exposure (RE) of aircraft crew due to cosmic rays (CR). On the other hand real-time CR data measured with the ground based neutron monitors (NMs) are collected worldwide and available online. This is an opportunity for comparison of long-term observations of RE at altitudes of about 10km, where composition and energy spectra of secondary particles differ from those on the ground, with the data from NMs. Our contribution presents examples of such type of comparison...
November 2016: Life Sciences in Space Research
https://www.readbyqxmd.com/read/27993187/hibernation-for-space-travel-impact-on-radioprotection
#6
REVIEW
Matteo Cerri, Walter Tinganelli, Matteo Negrini, Alexander Helm, Emanuele Scifoni, Francesco Tommasino, Maximiliano Sioli, Antonio Zoccoli, Marco Durante
Hibernation is a state of reduced metabolic activity used by some animals to survive in harsh environmental conditions. The idea of exploiting hibernation for space exploration has been proposed many years ago, but in recent years it is becoming more realistic, thanks to the introduction of specific methods to induce hibernation-like conditions (synthetic torpor) in non-hibernating animals. In addition to the expected advantages in long-term exploratory-class missions in terms of resource consumptions, aging, and psychology, hibernation may provide protection from cosmic radiation damage to the crew...
November 2016: Life Sciences in Space Research
https://www.readbyqxmd.com/read/27886995/cosmic-radiation-exposure-of-future-hypersonic-flight-missions
#7
L Koops
Cosmic radiation exposure in air traffic grows with flight altitude, geographical latitude and flight time. For future high-speed intercontinental point-to-point travel, the trade-off between reduced flight time and enhanced dose rate at higher flight altitudes is investigated. Various representative (partly) hypersonic cruise missions are considered and in dependence on solar activity the integral route dose is calculated for envisaged flight profiles and trajectories. Our results are compared to those for corresponding air connections served by present day subsonic airliners...
November 24, 2016: Radiation Protection Dosimetry
https://www.readbyqxmd.com/read/27881872/in-vitro-and-in-vivo-assessment-of-direct-effects-of-simulated-solar-and-galactic-cosmic-radiation-on-human-hematopoietic-stem-progenitor-cells
#8
C Rodman, G Almeida-Porada, S K George, J Moon, S Soker, T Pardee, M Beaty, P Guida, S P Sajuthi, C D Langefeld, S J Walker, P F Wilson, C D Porada
Future deep space missions to Mars and near-Earth asteroids will expose astronauts to chronic solar energetic particles (SEP) and galactic cosmic ray (GCR) radiation, and likely one or more solar particle events (SPEs). Given the inherent radiosensitivity of hematopoietic cells and short latency period of leukemias, space radiation-induced hematopoietic damage poses a particular threat to astronauts on extended missions. We show that exposing human hematopoietic stem/progenitor cells (HSC) to extended mission-relevant doses of accelerated high-energy protons and iron ions leads to the following: (1) introduces mutations that are frequently located within genes involved in hematopoiesis and are distinct from those induced by γ-radiation; (2) markedly reduces in vitro colony formation; (3) markedly alters engraftment and lineage commitment in vivo; and (4) leads to the development, in vivo, of what appears to be T-ALL...
December 9, 2016: Leukemia: Official Journal of the Leukemia Society of America, Leukemia Research Fund, U.K
https://www.readbyqxmd.com/read/27815023/comparative-analysis-of-the-serum-proteome-for-biomarker-discovery-to-reveal-hepatotoxicity-induced-by-iron-ion-radiation-in-mice
#9
Hongyan Li, Yuxuan He, Cuixia Di, Jiawei Yan, Hong Zhang
AIMS: Proteomic analysis of serum biomarkers to determine liver toxicity after exposure to cosmic radiation has not been performed previously. This study was to identify serum biomarkers associated with hepatotoxicity following exposure to iron ion radiation. MAIN METHODS: Male mice were whole-body irradiated with a 2grayunit (Gy) iron ion beam, and after 3months, serum and liver samples were collected. Two-dimensional electrophoresis (2-DE) was used to separate the identified serum proteins, and matrix-assisted laser desorption/ionization tandem mass spectrometry (MALDI-TOF-TOF) was performed to identify differentially expressed proteins...
December 15, 2016: Life Sciences
https://www.readbyqxmd.com/read/27798410/comparison-of-the-effective-dose-rate-to-aircrew-members-using-hybrid-computational-phantoms-in-standing-and-sitting-postures
#10
M C Alves, D C Galeano, W S Santos, Choonsik Lee, Wesley E Bolch, John G Hunt, A X da Silva, A B Carvalho
Aircraft crew members are occupationally exposed to considerable levels of cosmic radiation at flight altitudes. Since aircrew (pilots and passengers) are in the sitting posture for most of the time during flight, and up to now there has been no data on the effective dose rate calculated for aircrew dosimetry in flight altitude using a sitting phantom, we therefore calculated the effective dose rate using a phantom in the sitting and standing postures in order to compare the influence of the posture on the radiation protection of aircrew members...
October 31, 2016: Journal of Radiological Protection: Official Journal of the Society for Radiological Protection
https://www.readbyqxmd.com/read/27776994/combined-effects-of-antiorthostatic-suspension-and-ionizing-radiation-on-the-behaviour-and-neurotransmitters-changes-in-different-brain-structures-of-rats
#11
V S Kokhan, M I Matveeva, A S Bazyan, V S Kudrin, A Mukhametov, A S Shtemberg
Space flight factors (SFF) significantly affect the operating activity of astronauts during deep space missions. In contrast to an orbital flight, leaving the Earth's magnetic field is fraught with the dangers of exposure to ionizing radiation and more specifically, the high-energy nuclei component of galactic cosmic rays. Microgravity, just another critical non-radiation factor, significantly affects the normal functioning of the CNS. Some morphological structures of the brain, such as the prefrontal cortex and the hippocampus, that are rich in monoaminergic and acetylcholinergic neurones, are the most sensitive to the effects of ionizing radiation and non-radiation spaceflight factors (SFF)...
October 21, 2016: Behavioural Brain Research
https://www.readbyqxmd.com/read/27766455/tardigrades-in-space-research-past-and-future
#12
Erdmann Weronika, Kaczmarek Łukasz
To survive exposure to space conditions, organisms should have certain characteristics including a high tolerance for freezing, radiation and desiccation. The organisms with the best chance for survival under such conditions are extremophiles, like some species of Bacteria and Archea, Rotifera, several species of Nematoda, some of the arthropods and Tardigrada (water bears). There is no denying that tardigrades are one of the toughest animals on our planet and are the most unique in the extremophiles group...
October 20, 2016: Origins of Life and Evolution of the Biosphere
https://www.readbyqxmd.com/read/27721383/cosmic-radiation-exposure-and-persistent-cognitive-dysfunction
#13
Vipan K Parihar, Barrett D Allen, Chongshan Caressi, Stephanie Kwok, Esther Chu, Katherine K Tran, Nicole N Chmielewski, Erich Giedzinski, Munjal M Acharya, Richard A Britten, Janet E Baulch, Charles L Limoli
The Mars mission will result in an inevitable exposure to cosmic radiation that has been shown to cause cognitive impairments in rodent models, and possibly in astronauts engaged in deep space travel. Of particular concern is the potential for cosmic radiation exposure to compromise critical decision making during normal operations or under emergency conditions in deep space. Rodents exposed to cosmic radiation exhibit persistent hippocampal and cortical based performance decrements using six independent behavioral tasks administered between separate cohorts 12 and 24 weeks after irradiation...
October 10, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27707907/on-the-possibility-of-galactic-cosmic-ray-induced-radiolysis-powered-life-in-subsurface-environments-in-the-universe
#14
Dimitra Atri
Photosynthesis is a mechanism developed by terrestrial life to utilize the energy from photons of solar origin for biological use. Subsurface regions are isolated from the photosphere, and consequently are incapable of utilizing this energy. This opens up the opportunity for life to evolve alternative mechanisms for harvesting available energy. Bacterium Candidatus Desulforudis audaxviator, found 2.8 km deep in a South African mine, harvests energy from radiolysis, induced by particles emitted from radioactive U, Th and K present in surrounding rock...
October 2016: Journal of the Royal Society, Interface
https://www.readbyqxmd.com/read/27693159/effects-of-etching-time-on-alpha-tracks-in-solid-state-nuclear-track-detectors
#15
Gavin Gillmore, David Wertheim, Simon Crust
Solid State Nuclear Track Detectors (SSNTDs) are used extensively for monitoring alpha particle radiation, neutron flux and cosmic ray radiation. Radon gas inhalation is regarded as being a significant contributory factor to lung cancer deaths in the UK each year. Gas concentrations are often monitored using CR39 based SSNTDs as the natural decay of radon results in alpha particles which form tracks in these detectors. Such tracks are normally etched for about 4h to enable microscopic analysis. This study examined the effect of etching time on the appearance of alpha tracks in SSNTDs by collecting 2D and 3D image datasets using laser confocal microscope imaging techniques...
January 1, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/27662785/charged-particle-spectra-measured-during-the-transit-to-mars-with-the-mars-science-laboratory-radiation-assessment-detector-msl-rad
#16
Bent Ehresmann, Donald M Hassler, Cary Zeitlin, Jingnan Guo, Jan Köhler, Robert F Wimmer-Schweingruber, Jan K Appel, David E Brinza, Scot C R Rafkin, Stephan I Böttcher, Sönke Burmeister, Henning Lohf, Cesar Martin, Eckart Böhm, Daniel Matthiä, Günther Reitz
The Mars Science Laboratory (MSL) started its 253-day cruise to Mars on November 26, 2011. During cruise the Radiation Assessment Detector (RAD), situated on board the Curiosity rover, conducted measurements of the energetic-particle radiation environment inside the spacecraft. This environment consists mainly of galactic cosmic rays (GCRs), as well as secondary particles created by interactions of these GCRs with the spacecraft. The RAD measurements can serve as a proxy for the radiation environment a human crew would encounter during a transit to Mars, for a given part of the solar cycle, assuming that a crewed vehicle would have comparable shielding...
August 2016: Life Sciences in Space Research
https://www.readbyqxmd.com/read/27651568/radiological-risk-assessment-of-cosmic-radiation-at-aviation-altitudes-a-trip-from-houston-intercontinental-airport-to-lagos-international-airport
#17
Paschal Ikenna Enyinna
Radiological risk parameters associated with aircrew members traveling from Houston Intercontinental Airport to Lagos International Airport have been computed using computer software called EPCARD (version 3.2). The mean annual effective dose of radiation was computed to be 2.94 mSv/year. This result is above the standard permissible limit of 1 mSv/year set for the public and pregnant aircrew members but below the limit set for occupationally exposed workers. The Risk of cancer mortality and excess career time cancer risk computed ranged from 3...
July 2016: Journal of Medical Physics
https://www.readbyqxmd.com/read/27650664/evaluation-of-world-population-weighted-effective-dose-due-to-cosmic-ray-exposure
#18
Tatsuhiko Sato
After the release of the Report of the United Nations Scientific Committee of the Effects of Atomic Radiation in 2000 (UNSCEAR2000), it became commonly accepted that the world population-weighted effective dose due to cosmic-ray exposure is 0.38 mSv, with a range from 0.3 to 2 mSv. However, these values were derived from approximate projections of altitude and geographic dependences of the cosmic-ray dose rates as well as the world population. This study hence re-evaluated the population-weighted annual effective doses and their probability densities for the entire world as well as for 230 individual nations, using a sophisticated cosmic-ray flux calculation model in tandem with detailed grid population and elevation databases...
2016: Scientific Reports
https://www.readbyqxmd.com/read/27649730/high-level-production-of-exopolysaccharides-by-a-cosmic-radiation-induced-mutant-m270-of-the-maitake-medicinal-mushroom-grifola-frondosa-agaricomycetes
#19
Chen Zhao, Xue-Mei Tian, Guang-Yuan Wang, Ai-Rong Song, Wen-Xing Liang
A new Grifola frondosa mutant, M270, was successfully isolated for high production of exopolysaccharides (EPSs) using cosmic radiation-induced mutagenesis. We found that the mutant M270 had a clearer and thicker EPS layer (~10 µm) adhering to mycelia than those of its parent strain 265 after Congo red staining. In the 20-L batch fermentation for M270, 10.3 g/L of EPS and 17.9 g/L of dry mycelia biomass were obtained after 204 hours of fermentation. Furthermore, a main water-soluble fraction (EP1) in the EPS was purified from M270 and then confirmed to be heteroglycan-protein complex with 91% (w/w) total carbohydrates and 9% (w/w) total proteins...
2016: International Journal of Medicinal Mushrooms
https://www.readbyqxmd.com/read/27599606/f-t-teleparallel-gravity-and-cosmology
#20
Yi-Fu Cai, Salvatore Capozziello, Mariafelicia De Laurentis, Emmanuel N Saridakis
Over recent decades, the role of torsion in gravity has been extensively investigated along the main direction of bringing gravity closer to its gauge formulation and incorporating spin in a geometric description. Here we review various torsional constructions, from teleparallel, to Einstein-Cartan, and metric-affine gauge theories, resulting in extending torsional gravity in the paradigm of f (T) gravity, where f (T) is an arbitrary function of the torsion scalar. Based on this theory, we further review the corresponding cosmological and astrophysical applications...
October 2016: Reports on Progress in Physics
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