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At least 163 records · Page 9Linked to original sources
PubMed1979

Genetic effects of cosmic radiation on bacteriophage T4Br+ (on materials of biological experiment "Soyuz-Apollo").

During the experiment "Spore-ring Forming Fungi Biorhythm" of the Apollo-Soyuz test project the Rhythm-1 apparatus contained a dried film culture of bacteriophage T4Br+, growing cultures of Actinomyces and plastic nuclear particle detectors. The following were studied: the frequency of induction of r mutations in the bacteriophage film per 2 X 10(4) surviving particles, the spectrum of mutant types obtained (rI, rII, rIII), and the possible molecular mechanisms for the occurrence of rII mutants with due regard to the registered tracks of heavy nuclear particles. The studies showed that the local radiation due to heavy nuclear particle tracks plays a major role in space radiation damage.

Bacteriophage T4↗
PubMed1997

Formation of oligopeptides on the surface of small bodies in solar system by cosmic radiation.

The present experiment indicates that oligopeptides are easily produced in solid state from mixtures of simple amino acids by irradiating with high energy charged particles. We investigated such amino acids and their mixtures as tryptophan, tyrosine and glycine. The thin films was irradiated with protons (6.6 MeV). Such dipeptides as Trp-Trp, Gly-Tyr, Tyr-Gly, and Tyr-Tyr have been detected as products of irradiation. Cosmic rays might be an effective energy source for abiotic formation of bioorganic compounds on the surface of small bodies in the solar system on early stage of formation of planets as well as at present day.

Amino Acids↗
PubMedDate not supplied

[Cytogenetic effects in experimental exposure to the heavy charged particles of galactic cosmic radiation on the Kosmos-1129 biosatellite].

The experiment was carried out on lattice (Lactuca sativa) seeds flown in a biocontainer equipped with plastic detectors to record heavy charged particles (HCP). The purpose of the experiment was to determine the yield of aberrant cells as a result of irradiation, and to identify this effect as a function of HCP topography in the seed. The cytogenetic examination of flight seedlings revealed a significant difference between the seeds which were hit with HCP and those that remained intact. This indicates a significant contribution of the heavy component of galactic cosmic rediation into the radiobiological effect. The relationship between the radiobiological effect and the HCP topography in the seed was established: zones of the root and stem meristema proved to be most sensitive targets.

Chromosome Aberrations↗
PubMedDate not supplied

[Partial shielding of the bone marrow as a method of local protection of the body from the effects of cosmic radiation].

This paper reviews existing data on bone marrow partial shielding in animal studies with reference to partial-body protection in space radiobiology and medicine. Analysis of reported data indicates the efficacy of the method to protect animals (including dogs) exposed to gamma-radiation and high-energy protons. Experimental findings that demonstrate the effectiveness of bone marrow partial shielding show that this method may be used for partial-body protection in space flight.

Animals↗
PubMed2002

Response of TL dosemeters to cosmic radiation on board passenger aircraft.

Measurements were performed with various LiF based TLDs on board seven Polish aircraft, flying long-distance or middle-distance routes. All of the 7LiF detectors used (various types of 7LiF:Mg,Ti and 7LiF:Mg,Cu,P detectors), which measure the non-neutron component of the radiation field, produced consistent results. It was found that the characteristics of the TLD response (ratio of different detector responses, glow curve shapes) after doses of radiation at flying altitudes differ from those obtained after exposure at the CERN facility (CERF), suggesting a lower contribution of densely ionising radiation. The neutron induced TL signal was also more affected by the thickness of the holder, suggesting the presence of a softer neutron energy spectrum at flight altitudes. Further in-flight and CERF exposures of detectors are planned to resolve these issues.

Aerospace Medicine↗
PubMed2004

Exposure of aircraft crew to cosmic radiation: on-board intercomparison of various dosemeters.

Owing to their professional activity, flight crews may receive a dose of some millisieverts within a year; airline passengers may also be concerned. The effective dose is to be estimated using various experimental and calculation tools. The European project DOSMAX (Dosimetry of Aircrew Exposure during Solar Maximum) was initiated in 2000 extending to 2004 to complete studies over the current solar cycle during the solar maximum phase. To compare various dosemeters in real conditions simultaneously in the same radiation field, an intercomparison was organised aboard a Paris-Tokyo round-trip flight. Both passive and active detectors were used. Good agreement was observed for instruments determining the different components of the radiation field; the mean ambient dose equivalent for the round trip was 129 +/- 10 microSv. The agreement of values obtained for the total dose obtained by measurements and by calculations is very satisfying.

Aircraft↗
PubMedDate not supplied

[Detection of pulsed cosmic radiation].

Dynamics of the oxidation rate of unithiol (sodium dimercaptopropansulfonate) by sodium nitrite was studied under perfect ecological conditions in Antarctica. Short-term spikes (signals) in optical density of the examined solution were found. Special features of these signals, such as the high penetrating ability, the obvious dependence of number of signals on the Sun' longitude, and the high speed of propagation (V > or = 300,000 km/s), indicate the astrophysical origin and possible gravitational causality of these signals.

Cosmic Radiation↗
PubMedDate not supplied

[Electrostatic protection from cosmic radiation (the current status and prospects)].

Conduction currents of the vacuum atmosphere near the spacecraft were measured in an electrostatic shielding and an electrostatic shielding module in electrostatic fields of about 10(7) Wt/m at a voltage of 3 X 10(5) V onboard Cosmos-605, 690, 732 and 936. The resultant conduction currents (less than or equal to 10(-9) A/m2) give evidence that the vacuum environment has high electroinsulation properties which contradicts the concepts derived from ground-based studies. Using up-to-date high-voltage devices, it appears possible to develop an efficient electrostatic shielding which will be of a low weight and a low power consumption.

Cosmic Radiation↗
PubMed2004

Cosmic radiation exposure of aircraft crew: compilation of measured and calculated data.

The aim of the working group has been to bring together, in particular from European research groups, the available, preferably published, experimental data and results of calculations, together with detailed descriptions of the methods of measurement and calculation. The purpose is to provide a dataset for all European Union Member States for the assessment of individual doses and/or to assess the validity of different approaches, and to provide an input to technical recommendations by the Article 31 group of experts and the European Commission. The radiation protection quantity of interest is effective dose, E (ISO), but the comparison of measurement results obtained by different methods or groups, and comparison of measurement results and the results of calculations, is done in terms of the operational quantity ambient dose equivalent, H*(10). The final report giving the results of the investigations will be published by the European Commission Directorate General Transport and Energy. This paper gives a preview of the report.

Aircraft↗
PubMed1996

Exposure to cosmic radiation of British Airways flying crew on ultralonghaul routes.

British Airways has carried out radiation monitoring in Concorde for more than 20 years and has used a heuristic model based on data quoted by the National Aeronautics and Space Administration (NASA) to model radiation exposure in all longhaul fleets. From these data it has been calculated that no flight deck crew would exceed the control level of 6 mSv/y currently under consideration by regulatory authorities, which is three tenths of the occupational dose limit of 20 mSv/y recommended by the International Commission on Radiological Protection (ICRP). The model suggested that less than 4% of cabin crew based in Tokyo flying only between London and Japan could reach or exceed the 6 mSv/y level, based on a predicted effective dose rate of 7 microSv/h. To validate this calculation a sampling measurement programme was carried out on nine round trips flown by a Boeing 747-400 between London and Tokyo. The radiation field was measured with dosimeters used for routine personal monitoring (thermoluminescence dosimeters (TLDs) and polyallydiglycol carbonate neutron dosimeters). The limitations of the methodology are acknowledged, but the results indicate that the effective dose rate was 6 microSv/h which is consistent with the predicted effective dose rate of 7 microSv/h. This result, which is in accordance with other reported studies indicates that it is unlikely that any of the cabin crew based in Tokyo exceeded the 6 mSv/y level. In accordance with "as low as reasonably achievable" principles British Airways will continue to monitor flying crew routes and hours flown to ensure compliance.

Aerospace Medicine↗
PubMed1975

The effects of cosmic radiation on pocket mice aboard Apollo XVII: V. preflight studies on tolerance of pocket mice to oxygen and heat. Part IV. observations on the brain.

Experiments designed to ascertain the effects of oxgen at 8, 10, and 12 psi partial pressure on the brains of pocket mice (Perognathus longimembris) were carried out at room temperature (24 degrees C, 75 degrees F) and at 32 degrees C (93 degrees F). The animals exposed to 8-12 psi at 32 degrees C had been in earlier KO2 oxygen tests. Five animals exposed either to 10 or 12 psi (517 mm or 620 mm HG) PO2 at 32 degrees C died during the course of the tests, possibly as a consequence of injury sustained by the earlier PO2 testing. Autopsy was not carried out. In the other 36 exposed animals, no pathological changes were observed in the brain. It is thus highly probable that oxygen pressures at the hyperbaric levels to which the pocket mice would be exposed during the Apollo XVII mission would not result in any lesions in the brain.

Adaptation, Physiological↗
PubMed1999

Cosmic radiation exposure on Canadian-based commercial airline routes.

As a result of the recent recommendations of ICRP 60 and in anticipation of possible regulation on occupational exposure of commercial aircrew, a two-part investigation was carried out over a one-year period to determine the total dose equivalent on representative Canadian-based flight routes. As part of the study, a dedicated scientific measurement flight (using both a conventional suite of powered detectors and passive dosimetry) was used to characterise the complex mixed radiation field and to intercompare the various instrumentation. In the other part of the study, volunteer aircrew carried (passive) neutron bubble detectors during their routine flight duties. From these measurements, the total dose equivalent was derived for a given route with a knowledge of the neutron fraction as determined from the scientific flight and computer code (CARI-LF) calculations. This investigation has yielded an extensive database of over 3100 measurements providing the total dose equivalent for 385 different routes. By folding in flight frequency information and the accumulated flight hours, the annual occupational exposures of 26 flight crew have also been determined. This study has indicated that most Canadian-based domestic and international aircrew will exceed the proposed annual ICRP 60 public limit of 1 mSv.y-1, but will he well below the occupational limit of 20 mSv.y-1.

Aerospace Medicine↗