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Cosmic Radiation

Rutulkumar Patel, Yulan Qing, Lucy Kennedy, Yan Yan, John Pink, Brittany Aguila, Amar Desai, Stanton L Gerson, Scott M Welford
One of the major health concerns on long-duration space missions will be radiation exposure to the astronauts. Outside the earth's magnetosphere, astronauts will be exposed to galactic cosmic rays (GCR) and solar particle events that are principally composed of protons and He, Ca, O, Ne, Si, Ca, and Fe nuclei. Protons are by far the most common species, but the higher atomic number particles are thought to be more damaging to biological systems. Evaluation and amelioration of risks from GCR exposure will be important for deep space travel...
April 14, 2018: Stem Cells Translational Medicine
Afshin Beheshti, Jack Miller, Yared Kidane, Daniel Berrios, Samrawit G Gebre, Sylvain V Costes
Accurate assessment of risks of long-term space missions is critical for human space exploration. It is essential to have a detailed understanding of the biological effects on humans living and working in deep space. Ionizing radiation from galactic cosmic rays (GCR) is a major health risk factor for astronauts on extended missions outside the protective effects of the Earth's magnetic field. Currently, there are gaps in our knowledge of the health risks associated with chronic low-dose, low-dose-rate ionizing radiation, specifically ions associated with high (H) atomic number (Z) and energy (E)...
April 13, 2018: Radiation Research
Ryley Hill, Kiyoshi W Masui, Douglas Scott
Cosmic background (CB) radiation, encompassing the sum of emission from all sources outside our own Milky Way galaxy across the entire electromagnetic spectrum, is a fundamental phenomenon in observational cosmology. Many experiments have been conceived to measure it (or its constituents) since the extragalactic Universe was first discovered; in addition to estimating the bulk (cosmic monopole) spectrum, directional variations have also been detected over a wide range of wavelengths. Here we gather the most recent of these measurements and discuss the current status of our understanding of the CB from radio to γ-ray energies...
January 1, 2018: Applied Spectroscopy
Nadia Mulinacci, Alessio Valletta, Valentina Pasqualetti, Marzia Innocenti, Camilla Giuliani, Maria Bellumori, Giulia De Angelis, Alessia Carnevale, Vittoria Locato, Cristina Di Venanzio, Laura De Gara, Gabriella Pasqua
Humans are exposed to ionizing radiations in medical radiodiagnosis and radiotherapy that cause oxidative damages and degenerative diseases. Airplane pilots, and even more astronauts, are exposed to a variety of potentially harmful factors, including cosmic radiations. Among the phytochemicals, phenols are particularly efficient in countering the oxidative stress. In the present study, different extracts obtained from plant food, plant by-products and dietary supplements, have been compared for their antioxidant properties before and after irradiation of 140 cGy, a dose absorbed during a hypothetical stay of three years in the space...
April 2, 2018: Natural Product Research
Franco Cortese, Dmitry Klokov, Andreyan Osipov, Jakub Stefaniak, Alexey Moskalev, Jane Schastnaya, Charles Cantor, Alexander Aliper, Polina Mamoshina, Igor Ushakov, Alex Sapetsky, Quentin Vanhaelen, Irina Alchinova, Mikhail Karganov, Olga Kovalchuk, Ruth Wilkins, Andrey Shtemberg, Marjan Moreels, Sarah Baatout, Evgeny Izumchenko, João Pedro de Magalhães, Artem V Artemov, Sylvain V Costes, Afshin Beheshti, Xiao Wen Mao, Michael J Pecaut, Dmitry Kaminskiy, Ivan V Ozerov, Morten Scheibye-Knudsen, Alex Zhavoronkov
While many efforts have been made to pave the way toward human space colonization, little consideration has been given to the methods of protecting spacefarers against harsh cosmic and local radioactive environments and the high costs associated with protection from the deleterious physiological effects of exposure to high-Linear energy transfer (high-LET) radiation. Herein, we lay the foundations of a roadmap toward enhancing human radioresistance for the purposes of deep space colonization and exploration...
March 6, 2018: Oncotarget
Kim Ngan Tran, Jong-Il Choi
PURPOSE: To study gene expression modulation in response to continuous whole-body exposure to low-dose-rate gamma radiation and improve our understanding of the mechanism of this impact at the molecular basis. MATERIALS AND METHODS: cDNA microarray method with complete pooling of samples was used to study expression changes in the transcriptome profile of livers from rats treated with prolonged low-dose-rate ionizing radiation relative to that of sham-irradiated rats...
March 20, 2018: International Journal of Radiation Biology
Vipan K Parihar, Mattia Maroso, Amber Syage, Barrett D Allen, Maria C Angulo, Ivan Soltesz, Charles L Limoli
Of the many perils associated with deep space travel to Mars, neurocognitive complications associated with cosmic radiation exposure are of particular concern. Despite these realizations, whether and how realistic doses of cosmic radiation cause cognitive deficits and neuronal circuitry alterations several months after exposure remains unclear. In addition, even less is known about the temporal progression of cosmic radiation-induced changes transpiring over the duration of a time period commensurate with a flight to Mars...
March 11, 2018: Experimental Neurology
Giorgia Cinelli, Tore Tollefsen, Peter Bossew, Valeria Gruber, Konstantins Bogucarskis, Luca De Felice, Marc De Cort
The European Atlas of Natural Radiation is a collection of maps displaying the levels of natural radioactivity caused by different sources. It has been developed and is being maintained by the Joint Research Centre (JRC) of the European Commission, in line with its mission, based on the Euratom Treaty: to collect, validate and report information on radioactivity levels in the environment of the EU Member States. This work describes the first version of the European Atlas of Natural Radiation, available in digital format through a web portal, as well as the methodology and results for the maps already developed...
February 26, 2018: Journal of Environmental Radioactivity
Rennan Barkana
The cosmic radio-frequency spectrum is expected to show a strong absorption signal corresponding to the 21-centimetre-wavelength transition of atomic hydrogen around redshift 20, which arises from Lyman-α radiation from some of the earliest stars. By observing this 21-centimetre signal-either its sky-averaged spectrum or maps of its fluctuations, obtained using radio interferometers-we can obtain information about cosmic dawn, the era when the first astrophysical sources of light were formed. The recent detection of the global 21-centimetre spectrum reveals a stronger absorption than the maximum predicted by existing models, at a confidence level of 3...
February 28, 2018: Nature
Judd D Bowman, Alan E E Rogers, Raul A Monsalve, Thomas J Mozdzen, Nivedita Mahesh
After stars formed in the early Universe, their ultraviolet light is expected, eventually, to have penetrated the primordial hydrogen gas and altered the excitation state of its 21-centimetre hyperfine line. This alteration would cause the gas to absorb photons from the cosmic microwave background, producing a spectral distortion that should be observable today at radio frequencies of less than 200 megahertz. Here we report the detection of a flattened absorption profile in the sky-averaged radio spectrum, which is centred at a frequency of 78 megahertz and has a best-fitting full-width at half-maximum of 19 megahertz and an amplitude of 0...
February 28, 2018: Nature
John D Boice, Elizabeth D Ellis, Ashley P Golden, David J Girardi, Sarah S Cohen, Heidi Chen, Michael T Mumma, Roy E Shore, Richard W Leggett
The purpose of this paper is to present an overview of ongoing work on the Million Worker Study (MWS), highlighting some of the key methods and progress so far as exemplified by the study of workers at the Mallinckrodt Chemical Works (MCW). The MWS began nearly 25 y ago and continues in a stepwise fashion, evaluating one study cohort at a time. It includes workers from U.S. Department of Energy (DOE) Manhattan Project facilities, U.S. Nuclear Regulatory Commission (NRC) regulated nuclear power plants, industrial radiographers, U...
April 2018: Health Physics
Olga A Smirnova, Francis A Cucinotta
A recently developed biologically motivated dynamical model of the assessment of the excess relative risk (ERR) for radiogenic leukemia among acutely/continuously irradiated humans (Smirnova, 2015, 2017) is applied to estimate the ERR for radiogenic leukemia among astronauts engaged in long-term interplanetary space missions. Numerous scenarios of space radiation exposure during space missions are used in the modeling studies. The dependence of the ERR for leukemia among astronauts on several mission parameters including the dose equivalent rates of galactic cosmic rays (GCR) and large solar particle events (SPEs), the number of large SPEs, the time interval between SPEs, mission duration, the degree of astronaut's additional shielding during SPEs, the degree of their additional 12-hour's daily shielding, as well as the total mission dose equivalent, is examined...
February 2018: Life Sciences in Space Research
Andrea Madella, Romain Delunel, Naki Akçar, Fritz Schlunegger, Marcus Christl
Terrestrial cosmogenic nuclide concentrations of detrital minerals yield catchment-wide rates at which hillslopes erode. These estimates are commonly used to infer millennial scale denudation patterns and to identify the main controls on mass-balance and landscape evolution at orogenic scale. The same approach can be applied to minerals preserved in stratigraphic records of rivers, although extracting reliable paleo-denudation rates from Ma-old archives can be limited by the target nuclide's half-life and by exposure to cosmic radiations after deposition...
February 2, 2018: Scientific Reports
M A Pereira, C A Federico, O L Gonçalez
A TLD-based dosimeter of polyethylene-lead-polyethylene, was developed and characterized with Monte Carlo simulations, using the MCNPX code. This passive system for the determination of the ambient dose equivalent (H*(10)) for neutrons over a wide energy range can be used for the dosimetry of neutrons from atmospheric cosmic radiation, on the ground, and onboard aircraft. A method assisted by Monte Carlo simulations that improves the calibration of fast neutron dosimeters based on moderation and thermalization of the incident fast flux and the measurement of the thermal flux by a sensor, which respond mainly to thermal neutrons, is presented in this work...
January 25, 2018: Radiation Protection Dosimetry
Juan García-Bellido
We test the Higgs dilaton inflation model (HDM) using the latest cosmological datasets, including the cosmic microwave background temperature, polarization and lensing data from the Planck satellite (2015), the BICEP and Keck Array experiments, the type Ia supernovae from the JLA catalogue, the baryon acoustic oscillations from CMASS, LOWZ and 6dF, the weak lensing data from the CFHTLenS survey and the matter power spectrum measurements from the latest SDSS data release. We find that the values of all cosmological parameters allowed by the HDM are well within the Planck satellite (2015) constraints...
March 6, 2018: Philosophical Transactions. Series A, Mathematical, Physical, and Engineering Sciences
Matthew J Abplanalp, Sándor Góbi, Alexandre Bergantini, Andrew M Turner, Ralf I Kaiser
Complex organic molecules are ubiquitous in star- and planet-forming regions as well as on comets such as on 67P/Churyumov-Gerasimenko, but their origins have remained largely unexplained until now. Here, we report the first laboratory detection of distinct C3 H8 O (propanol, methyl ethyl ether) and C4 H8 O (n-butanal, i-butanal) isomers formed within interstellar analog ices through interaction with ionizing radiation. This study reveals that complex organics with propyl (C3 H7 ) and butyl (C4 H9 ) groups can be synthesized easily in deep space and may act as key evolutionary tracers of a cosmic ray driven non-equilibrium chemistry in low temperature interstellar ices at 10 K...
March 5, 2018: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
Ekrem Aydiner
In this study, we consider nonlinear interactions between components such as dark energy, dark matter, matter and radiation in the framework of the Friedman-Robertson-Walker space-time and propose a simple interaction model based on the time evolution of the densities of these components. By using this model we show that these interactions can be given by Lotka-Volterra type equations. We numerically solve these coupling equations and show that interaction dynamics between dark energy-dark matter-matter or dark energy-dark matter-matter-radiation has a strange attractor for 0 > w de  >-1, w dm  ≥ 0, w m  ≥ 0 and w r  ≥ 0 values...
January 15, 2018: Scientific Reports
Qilai Zhao, Kaijun Zhou, Zisheng Wu, Changsheng Yang, Zhouming Feng, Huihui Cheng, Jiulin Gan, Mingying Peng, Zhongmin Yang, Shanhui Xu
The Earth's magnetic field has significant effects that protect us from cosmic radiation and provide navigation for biological migration. However, slow temporal variations originating in the liquid outer core invariably exist. To understand the working mechanism of the geomagnetic field and improve accuracy of navigation systems, a high-precision magnetometer is essential to measure the absolute magnetic field. A helium optically pumping magnetometer is an advanced approach, but its sensitivity and accuracy are directly limited by the low-frequency relative intensity noise and frequency stability characteristics of a light source...
January 1, 2018: Optics Letters
Munish Kumar, D Datta
No abstract text is available yet for this article.
October 2017: Journal of Medical Physics
Dae Woong Ham, Binglin Song, Jian Gao, Julien Yu, Rainer K Sachs
Customized open-source software is used to characterize, exemplify, compare and critically evaluate mathematical/computational synergy analysis methods currently used in biology, and used or potentially applicable in radiobiology. As examples, we reanalyze some published results on murine Harderian gland tumors and on in vitro chromosome aberrations induced by exposure to single-ion radiations that simulate components of the galactic cosmic ray field. Baseline no-synergy/no-antagonism-mixture dose-effect relationships are calculated for corresponding mixed fields...
March 2018: Radiation Research
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