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Research Containing: Radiation

Expression of p53-Regulated Proteins in Human Cultured Lymphoblastoid TSCE5 and WTK1 Cell Lines during Spaceflight

by on 22 August 2016in Biology & Biotechnology No comment

The aim of this study was to determine the biological effects of space radiations, microgravity, and the interaction of them on the expression of p53-regulated proteins. Space experiments were performed with two human cultured lymphoblastoid cell lines: one line (TSCE5) bears a wild-type p53 gene status, and another line (WTK1) bears a mutated p53 gene status. Under 1 gravity or microgravity conditions, the cells were grown in the cell biology experimental facility (CBEF) of the International Space Station for 8 days without experiencing the stress during launching and landing because the cells were frozen during these periods. Ground control samples were simultaneously cultured for 8 days in the CBEF on the ground for 8 days. After spaceflight, protein expression was analyzed using a PanoramaTM Ab MicroArray protein chips. It was found that p53-dependent up-regulated proteins in response to space radiations and space environment were MeCP2 (methyl CpG binding protein 2), and Notch1 (Notch homolog 1), respectively. On the other hand, p53-dependent down-regulated proteins were TGF-β, TWEAKR (tumor necrosis fac- tor-like weak inducer of apoptosis receptor), phosho-Pyk2 (Proline-rich tyrosine kinase 2), and 14-3-3θ/τ which were affected by microgravity, and DR4 (death receptor 4), PRMT1 (protein arginine methyltrans- ferase 1) and ROCK-2 (Rho-associated, coiled-coil containing protein kinase 2) in response to space radi- ations. ROCK-2 was also suppressed in response to the space environment. The data provides the p53- dependent regulated proteins by exposure to space radiations and/or microgravity during spaceflight. Our expression data revealed proteins that might help to advance the basic space radiation biology.

Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/22374402

Observation of radiation environment in the International Space Station in 2012–March 2013 by Liulin-5 particle telescope

by on 22 August 2016in Biology & Biotechnology, Earth Science and Remote Sensing

Since June 2007 the Liulin-5 charged particle telescope, located in the spherical tissue-equivalent phantom of the MATROSHKA-R project onboard the International Space Station (ISS), has been making measurements of the local energetic particle radiation environment. From 27 December 2011 to 09 March 2013 measurements were conducted in and outside the phantom located in the MIM1 module of the ISS. In this paper Liulin-5 dose rates, due to galactic cosmic rays and South Atlantic Anomaly trapped protons, measured during that period are presented. Particularly, dose rates and particle fluxes for the radiation characteristics in the phantom during solar energetic particle (SEP) events occurring in March and May 2012 are discussed. Liulin-5 SEP observations are compared with other ISS data, GOES proton fluxes as well as with solar energetic particle measurements obtained onboard the Mir space station during previous solar cycles.

Related URLs:
http://adsabs.harvard.edu/abs/2014JSWSC…4A..32S

Radiation Measurements Performed with Active Detectors Relevant for Human Space Exploration

by on 22 August 2016in Earth Science and Remote Sensing No comment

A reliable radiation risk assessment in space is a mandatory step for the development of countermeasures and long-duration mission planning in human spaceflight. Research in radiobiology provides information about possible risks linked to radiation. In addition, for a meaningful risk evaluation, the radiation exposure has to be assessed to a sufficient level of accuracy. Consequently, both the radiation models predicting the risks and the measurements used to validate such models must have an equivalent precision. Corresponding measurements can be performed both with passive and active devices. The former is easier to handle, cheaper, lighter, and smaller but they measure neither the time dependence of the radiation environment nor some of the details useful for a comprehensive radiation risk assessment. Active detectors provide most of these details and have been extensively used in the International Space Station. To easily access such an amount of data, a single point access is becoming essential. This review presents an ongoing work on the development of a tool that allows obtaining information about all relevant measurements performed with active detectors providing reliable inputs for radiation model validation.

Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/26697408

FURTHER ANALYSIS OF THE SPACE SHUTTLE EFFECTS ON THE ISS SAA DOSES

by on 22 August 2016in Biology & Biotechnology, Earth Science and Remote Sensing, Physical Sciences No comment

The data from the R3DE instrument of ESA’s EXPOSE-E mission outside the ISS at the European Technological Expose Facility (EuTEF) on the ESA Columbus module shows that the docking of the Space Shuttle with the International Space Station (ISS) decreased the South-Atlantic Anomaly (SAA) maxima dose rates from about 1500 Gy h-1 down to 600-700 Gy h-1 or by factor of 2. The dose rate data at the same time from another Bulgarian built instrument (R3DR) of the EXPOSE-R mission outside the Russian “Zvezda” module showed that: 1) before the Space Shuttle docking, the SAA dose rates measured with R3DR were higher (2500 Gy h-1) than the R3DE data; 2) The relative decrease of the SAA dose rates after the shuttle docking was only by a factor of 1.25. These differences are explained by the smaller shielding of R3DR from the body of ISS and by the larger distance of it from the body of Space Shuttle. Very similar data, but with smaller dose rates were obtained with a third Bulgarian built instrument (Liulin-5) inside Russian “Pirs” module. The analysis of the ascending/descending SAA dose rate maxima of the three instruments shows that the effect can be simply explained by the additional shielding against the 30 to 150 MeV protons of the SAA, provided by the 78 tons Shuttle to the instruments and by changing of the ISS 3D mass distribution when the ISS rotates.

Related URLs:
http://iafastro.directory/iac/archive/browse/IAC-11/A1/4/9918/

Precision Measurement of the Helium Flux in Primary Cosmic Rays of Rigidities 1.9 GV to 3 TV with the Alpha Magnetic Spectrometer on the International Space Station

by on 22 August 2016in Earth Science and Remote Sensing No comment

Knowledge of the precise rigidity dependence of the helium flux is important in understanding the origin, acceleration, and propagation of cosmic rays. A precise measurement of the helium flux in primary cosmic rays with rigidity (momentum/charge) from 1.9 GV to 3 TV based on 50 million events is presented and compared to the proton flux. The detailed variation with rigidity of the helium flux spectral index is presented for the first time. The spectral index progressively hardens at rigidities larger than 100 GV. The rigidity dependence of the helium flux spectral index is similar to that of the proton spectral index though the magnitudes are different. Remarkably, the spectral index of the proton to helium flux ratio increases with rigidity up to 45 GV and then becomes constant; the flux ratio above 45 GV is well described by a single power law.

Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/26636836

Preservation of Biomarkers from Cyanobacteria Mixed with Mars-Like Regolith Under Simulated Martian Atmosphere and UV Flux

by on 22 August 2016in Biology & Biotechnology, Earth Science and Remote Sensing No comment

The space mission EXPOSE-R2 launched on the 24th of July 2014 to the International Space Station is carrying the BIOMEX (BIOlogy and Mars EXperiment) experiment aimed at investigating the endurance of extremophiles and stability of biomolecules under space and Mars-like conditions. In order to prepare the analyses of the returned samples, ground-based simulations were carried out in Planetary and Space Simulation facilities. During the ground-based simulations, Chroococcidiopsis cells mixed with two Martian mineral analogues (phyllosilicatic and sulfatic Mars regolith simulants) were exposed to a Martian simulated atmosphere combined or not with UV irradiation corresponding to the dose received during a 1-year-exposure in low Earth orbit (or half a Martian year on Mars). Cell survival and preservation of potential biomarkers such as photosynthetic and photoprotective pigments or DNA were assessed by colony forming ability assays, confocal laser scanning microscopy, Raman spectroscopy and PCR-based assays. DNA and photoprotective pigments (carotenoids) were detectable after simulations of the space mission (570 MJ/m(2) of UV 200-400 nm irradiation and Martian simulated atmosphere), even though signals were attenuated by the treatment. The fluorescence signal from photosynthetic pigments was differently preserved after UV irradiation, depending on the thickness of the samples. UV irradiation caused a high background fluorescence of the Martian mineral analogues, as revealed by Raman spectroscopy. Further investigation will be needed to ensure unambiguous identification and operations of future Mars missions. However, a 3-month exposure to a Martian simulated atmosphere showed no significant damaging effect on the tested cyanobacterial biosignatures, pointing out the relevance of the latter for future investigations after the EXPOSE-R2 mission. Data gathered during the ground-based simulations will contribute to interpret results from space experiments and guide our search for life on Mars.

Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/26530341

Time serial analysis of the induced LEO environment within the ISS 6A

by on 9 June 2015in Technology Development & Demonstration No comment

Anisotropies in the low Earth orbit (LEO) radiation environment were found to influence the thermoluminescence detectors (TLD) dose within the (International Space Station) ISS 7A Service Module. Subsequently, anisotropic environmental models with improved dynamic time extrapolation have been developed including westward and northern drifts using AP8 Min & Max as estimates of the historic spatial distribution of trapped protons in the 1965 and 1970 era, respectively. In addition, a directional dependent geomagnetic cutoff model was derived for geomagnetic field configurations from the 1945 to 2020 time frame. A dynamic neutron albedo model based on our atmospheric radiation studies has likewise been required to explain LEO neutron measurements. The simultaneous measurements of dose and dose rate using four Liulin instruments at various locations in the US LAB and Node 1 has experimentally demonstrated anisotropic effects in ISS 6A and are used herein to evaluate the adequacy of these revised environmental models.

Related URLs:
http://www.sciencedirect.com/science/article/pii/S0273117706007885

International space station: A testbed for experimental and computational dosimetry

by on 9 June 2015in Technology Development & Demonstration No comment

The ISS and the prior station Mir provided the proving ground for future human long-duration space activity. A recent European Space Agency study recommended “Measurement campaigns on the ISS form the ideal tool for experimental validation of radiation environment models, of transport code algorithms and reaction cross sections”. Indeed, prior measurements on Shuttle have provided vital information impacting both transport code and environmental model development. Recent studies using the ISS 7A configuration with TLD area monitors demonstrated that computational dosimetry requires environmental models with accurate anisotropic and dynamic behavior, detailed information on rack loading, and an accurate 6 degree-of-freedom description of the ISS trajectory. The ISS model is now configured for 11A and uses an anisotropic and dynamic geomagnetic transmission and trapped proton models. The ISS 11A is instrumented with both passive and active dosimetric devices. Time resolved measurements have the advantage of isolating trapped proton and galactic cosmic ray components as was essential to transport code validation in Shuttle data analysis. ISS 11A model validation will begin with passive dosimetry as was used with ISS 7A. Directional dependent active measurements will play an important role in the validation of environmental model anisotropies.

Related URLs:
http://www.sciencedirect.com/science/article/pii/S0273117705001742

Embrittlement of MISSE 5 Polymers After 13 Months of Space Exposure

by on 9 June 2015in Technology Development & Demonstration No comment

Understanding space environment induced degradation of spacecraft materials is essential when designing durable and stable spacecraft components. As a result of space radiation, debris impacts, atomic oxygen interaction, and thermal cycling, the outer surfaces of space materials degrade when exposed to low Earth orbit (LEO). The objective of this study was to measure the embrittlement of 37 thin film polymers after LEO space exposure. The polymers were flown aboard the International Space Station and exposed to the LEO space environment as part of the Materials International Space Station Experiment 5 (MISSE 5). The samples were flown in a nadir-facing position for 13 months and were exposed to thermal cycling along with low doses of atomic oxygen, direct solar radiation and omni-directional charged particle radiation. The samples were analyzed for space-induced embrittlement using a bend-test procedure in which the strain necessary to induce surface cracking was determined. Bend-testing was conducted using successively smaller mandrels to apply a surface strain to samples placed on a semi-suspended pliable platform. A pristine sample was also tested for each flight sample. Eighteen of the 37 flight samples experienced some degree of surface cracking during bend-testing, while none of the pristine samples experienced any degree of cracking. The results indicate that 49% of the MISSE 5 thin film polymers became embrittled in the space environment even though they were exposed to low doses (~2.75 krad (Si) dose through 127 μm Kapton) of ionizing radiation.

Related URLs:
http://dx.doi.org/10.1007/978-3-642-30229-9_35

BRADOS – Dose determination in the Russian Segment of the International Space Station

by on 9 June 2015in Technology Development & Demonstration No comment

In the frame of the joint experiment BRADOS-1, absorbed dose and average linear energy transfer were assessed by means of 7LiF:Mg,Ti (TLD-700) thermoluminescence detectors for different panels onboard the Russian Segment of the International Space Station in the timeframe between February and October 2001 (248 days). A technique is presented to correct the measured absorbed dose values for thermoluminescent efficiency in the radiation climate onboard the spacecraft. Average linear energy transfer is determined from the high-temperature thermoluminescence emission in the TLD-700 glowcurve and used as a parameter in the thermoluminescent-efficiency correction. Depending on the shielding distribution, the efficiency–corrected absorbed dose varies between 168(2) μGy/d in panel No. 318 (core block ceiling) and 249(4) μGy/d in panel No. 443 (starboard-side commander cabin). The experimental data are compared with model calculations using detailed shielding distributions and orbit parameters as input.

Related URLs:
http://www.sciencedirect.com/science/article/pii/S0273117706000251