Sample records for nrpb
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Degaki, Theri Leica; Demasi, Marcos Angelo Almeida; Sogayar, Mari Cleide
2009-11-01
Upon searching for glucocorticoid-regulated cDNA sequences associated with the transformed to normal phenotypic reversion of C6/ST1 rat glioma cells, we identified Nrp/b (nuclear restrict protein in brain) as a novel rat gene. Here we report on the identification and functional characterization of the complete sequence encoding the rat NRP/B protein. The cloned cDNA presented a 1767 nucleotides open-reading frame encoding a 589 amino acids residues sequence containing a BTB/POZ (broad complex Tramtrack bric-a-brac/Pox virus and zinc finger) domain in its N-terminal region and kelch motifs in its C-terminal region. Sequence analysis indicates that the rat Nrp/b displays a high level of identity with the equivalent gene orthologs from other organisms. Among rat tissues, Nrp/b expression is more pronounced in brain tissue. We show that overexpression of the Nrp/b cDNA in C6/ST1 cells suppresses anchorage independence in vitro and tumorigenicity in vivo, altering their malignant nature towards a more benign phenotype. Therefore, Nrp/b may be postulated as a novel tumor suppressor gene, with possible relevance for glioblastoma therapy.
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Sonawane, A U; Shirva, V K; Pradhan, A S
2010-02-01
Skin entrance doses (SEDs) were estimated by carrying out measurements of air kerma from 101 X-ray machines installed in 45 major and selected hospitals in the country by using a silicon detector-based dose Test-O-Meter. 1209 number of air kerma measurements of diagnostic projections for adults have been analysed for seven types of common diagnostic examinations, viz. chest (AP, PA, LAT), lumbar spine (AP, LAT), thoracic spine (AP, LAT), abdomen (AP), pelvis (AP), hip joints (AP) and skull (PA, LAT) for different film-screen combinations. The values of estimated diagnostic reference levels (DRLs) (third quartile values of SEDs) were compared with guidance levels/DRLs of doses published by the IAEA-BSS-Safety Series No. 115, 1996; HPA (NRPB) (2000 and 2005), UK; CRCPD/CDRH (USA), European Commission and other national values. The values of DRLs obtained in this study are comparable with the values published by the IAEA-BSS-115 (1996); HPA (NRPB) (2000 and 2005) UK; EC and CRCPD/CDRH, USA including values obtained in previous studies in India.
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ERIC Educational Resources Information Center
Council on Library and Information Resources, 2009
2009-01-01
This is the third of three studies of copyright and sound recordings commissioned by the National Recording Preservation Board (NRPB) in support of the congressionally mandated study of the state of audio preservation in the United States. All three studies have focused on how laws pertaining to sound recordings made before 1972 affect…
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Preliminary results from an indoor radon thoron survey in Hungary.
Szeiler, G; Somlai, J; Ishikawa, T; Omori, Y; Mishra, R; Sapra, B K; Mayya, Y S; Tokonami, S; Csordás, A; Kovács, T
2012-11-01
More than half of the radiation dose of natural origin comes from radon. However, according to some surveys in certain cases, the radiation dose originating from thoron may be considerable. Among the factors disturbing the measurement of radon, the presence of thoron may also influence the measured radon value, making the estimated radiation exposure imprecise. Thoron has previously been surveyed, mainly in Asia; however, recent surveys for some European locations have found that significant thoron concentrations also need to be considered. In this survey, several types of commercially available SSNTDs (solid-state nuclear track detectors) capable of measuring both radon and thoron were placed at the same time in 73 houses and 7 workplaces in Hungary with 3-month exposition periods. In order to measure thoron, the distance of the detector sets was fixed as 15-20 cm from the walls. The radon concentration was measured with five types of SSNTDs: NRPB, NRPB SSI, Raduet, DTPS and DRPS. The first four types had relatively good accordance (within ± 10 %), but the results of the DRPS detectors were considerably lower when compared with other detectors for radon concentrations over 100 Bq m(-3). The thoron averages were provided by two different types of detectors: Raduet and DTPS. The difference between their average results was more than 30 % and was six times the maximum values. Therefore, the thoron measurement results were judged to be erroneous, and their measurement protocol should be clearly established for future work.
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1982-09-15
standards should be included in the report so we approached Mr. Frank Harlen of NRPB with a request that he should contribute to the project . The original...plan was that EHG should act as editor and project tco-ordinator wi’th Frank Harlen and me assisting. For reasons, not totally unconnected with. the... projected cross-sectional area of man of 0.7 m2 , and is absorbed without reflections or scatter, the resulting thermal load is 70W. This is less than the
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Jibiri, Nnamdi N; Olowookere, Christopher J
2016-11-08
In Nigeria, a large number of radiographic examinations are conducted yearly for various diagnostic purposes. However, most examinations carried out do not have records of doses received by the patients, and the employed exposure parameters used are not documented; therefore, adequate radiation dose management is hin-dered. The aim of the present study was to estimate the dose-area product (DAP) of patients examined in Nigeria, and to propose regional reference dose levels for nine common examinations (chest PA, abdomen AP, pelvis AP, lumbar AP, skull AP, leg AP, knee AP, hand AP, and thigh AP) undertaken in Nigeria. Measurement of entrance surface dose (ESD) was carried out using thermoluminescent dosimeter (TLD). Measured ESDS were converted into DAP using the beam area of patients in 12 purposely selected hospitals. Results of the study show that the maximum/ minimum ratio ranged from 3 for thigh AP to 57 in abdomen AP. The range of determined mean and 75th percentile DAPs were 0.18-17.16, and 0.25-28.59 Gy cm2, respectively. Data available for comparison show that 75th percentile DAPs in this study (in chest PA, abdomen AP, pelvis AP, lumbar AP) are higher than NRPB-HPE reference values. The DAP in this study is higher by factor of 31.4 (chest PA), 9.9 (abdomen AP), 2.2 (pelvis AP), and 2.1 (lumbar AP) than NRPB-HPE values. The relative higher dose found in this study shows nonoptimization of practice in Nigeria. It is expected that regular dose auditing and dose optimization implementation in Nigeria would lead to lower DAP value, especially in abdomen AP. The 75th percentile DAP distribution reported in this study could be taken as regional diagnostic reference level in the Southwestern Nigeria; however, a more extensive nationwide dose survey is required to establish national reference dose. © 2016 The Authors.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Holliday, B.
Attention is drawn to the lack of information available concerning the standards of radiation protection during dental radiography in the UK. Brief summaries are presented of three cases illustrating the type of hazards that might arise from faulty x-ray equipment or bad operating techniques. It is pointed out that the NRPB service to dentists offers a survey procedure designed to reduce or eleminate radiation exposures of patients. Data concerning beam size, quality, and duration of the x-ray exposure is obtained from a combined film and filted pack sent to the dentist, and this information is supplemented by a questionnaire. Themore » results are assessed with reference to the Code of Practice for the Protection of Persons against Ionizing Radiations arising from Medical and Dental Use. (UK)« less
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Denman, Antony; Groves-Kirkby, Christopher; Coskeran, Thomas; Parkinson, Steven; Phillips, Paul; Tornberg, Roges
2005-08-01
Although previous analysis of health benefits and cost-effectiveness of radon remediation in a series of houses in Northamptonshire suggested that testing and remediation was justified, recent results indicate fewer predicted affected houses than previously assumed. Despite numerous awareness campaigns, limited numbers of householders have tested their homes, only a minority of affected householders have remediated, and those most at risk generally fail to remediate. Moreover, a recent survey shows a wide range of public perception of radon risk, not significantly influenced by public health campaigns. These observations impact our previous analysis, which has been reviewed in the light of these observations. Following the declaration of Northamptonshire, UK, as a radon Affected Area in 1992, a series of public awareness campaigns encouraged householders to assess domestic radon levels and, if appropriate, to take action to reduce them. Despite these awareness campaigns, however, only moderate numbers of householders have taken remediatory action. The costs of such remedial work in a series of domestic properties in Northamptonshire, the radon level reduction achieved, and the resultant heath benefit to the residents, have been the subject of study by our group for some years. Previous analysis, based on estimates of the total number of affected houses derived from the National Radiological Protection Board (NRPB) test data for the area, suggested that a programme of testing and remediation in Northamptonshire could be justified. The NRPB has continued to initiate and to collate radon testing, and published further results in 2003. These results include revised predictions of the numbers of affected houses, now considered to be less than the numbers previously assumed. More recently, the availability of the European Community Radon Software (ECRS) has permitted calculation of individual, rather than population-average, risk, demonstrating that those most at risk are generally those who do not take action. In addition, a recent survey of risk perception shows an extremely wide range of public perception of radon risk, a perception that has not been significantly altered by public health campaigns. These predictions have profound effects, both on our previous analysis, particularly since only limited numbers of householders test their homes and even fewer remediate if they discover raised levels, and also on the public health strategies for this risk.
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Performance assessment for low-level waste disposal in the UK
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ashworth, A.B.
1995-12-31
British Nuclear Fuels plc (BNFL) operate a site for the disposal of Low Level Radioactive Waste at Drigg in West Cumbria, in North-West England. HMIP are responsible for the regulation of the site with regard to environmental discharges of radioactive materials, both operational and post-closure. This paper is concerned with post-closure matters only. Two post-closure performance assessments have been carried out for this site: one by the National Radiological Protection Board (NRPB) in 1987; and a subsequent one carried out on behalf of HMIP, completed in 1991. Currently, BNFL are preparing a Safety Case for continued operation of the Driggmore » site, and it expected that the core of this Case will comprise BNFL`s own analysis of post-closure performance. HMIP has developed procedures for the assessment of this Case, based upon experience of the previous Drigg assessments, and also upon the experience of similar work carried out in the assessment of Intermediate Level Waste (ILW) disposal at both deep and shallow potential sites. This paper describes the more important features of these procedures.« less
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An improved MCNP version of the NORMAN voxel phantom for dosimetry studies.
Ferrari, P; Gualdrini, G
2005-09-21
In recent years voxel phantoms have been developed on the basis of tomographic data of real individuals allowing new sets of conversion coefficients to be calculated for effective dose. Progress in radiation studies brought ICRP to revise its recommendations and a new report, already circulated in draft form, is expected to change the actual effective dose evaluation method. In the present paper the voxel phantom NORMAN developed at HPA, formerly NRPB, was employed with MCNP Monte Carlo code. A modified version of the phantom, NORMAN-05, was developed to take into account the new set of tissues and weighting factors proposed in the cited ICRP draft. Air kerma to organ equivalent dose and effective dose conversion coefficients for antero-posterior and postero-anterior parallel photon beam irradiations, from 20 keV to 10 MeV, have been calculated and compared with data obtained in other laboratories using different numerical phantoms. Obtained results are in good agreement with published data with some differences for the effective dose calculated employing the proposed new tissue weighting factors set in comparison with previous evaluations based on the ICRP 60 report.
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Sulieman, A; Elzaki, M; Alkhorayef, M; Babikir, E; Abuzaid, M; Dalton, A; Bradley, D
2016-11-01
Endoscopic retrograde cholangiopancreatography (ERCP) is an invasive technique that has been used for over 30 years in the diagnosis and management of pancreaticobiliary disorders. The objectives of this study were to evaluate the patient entrance surface air kerma doses (ESAK) and estimate the organ and effective doses during ERCP in three hospitals in Khartoum. A total of 55 patients were examined in three hospitals in Khartoum state, Sudan. Calibrated thermoluinescent dosimeters (TLD) were used to measure patients' ESAK. Organ and effective doses were estimated using National Radiological Protection Board (NRPB) software. The overall mean of ESAK for all ERCP procedures was 42.4mGy. The mean patient ESAK in Fedail (A), Soba (B) and Ibn sena (C) hospitals were 26.7mGy, 26.0mGy and 72.4mGy, respectively. The effective doses in three hospitals were 1.60, 1.56 and 2.67mSv in that order and the overall mean effective dose was 1.94mSv. Patient radiation doses vary widely among the hospitals. Patient ESAK is low compared to previous studies in the light of the current practice. Patient dose was decreased significantly in the last two decades. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Radiation dose reduction in a neonatal intensive care unit in computed radiography.
Frayre, A S; Torres, P; Gaona, E; Rivera, T; Franco, J; Molina, N
2012-12-01
The purpose of this study was to evaluate the dose received by chest x-rays in neonatal care with thermoluminescent dosimetry and to determine the level of exposure where the quantum noise level does not affect the diagnostic image quality in order to reduce the dose to neonates. In pediatric radiology, especially the prematurely born children are highly sensitive to the radiation because of the highly mitotic state of their cells; in general, the sensitivity of a tissue to radiation is directly proportional to its rate of proliferation. The sample consisted of 208 neonatal chest x-rays of 12 neonates admitted and treated in a Neonatal Intensive Care Unit (NICU). All the neonates were preterm in the range of 28-34 weeks, with a mean of 30.8 weeks. Entrance Surface Doses (ESD) values for chest x-rays are higher than the DRL of 50 μGy proposed by the National Radiological Protection Board (NRPB). In order to reduce the dose to neonates, the optimum image quality was achieved by determining the level of ESD where level noise does not affect the diagnostic image quality. The optimum ESD was estimated for additional 20 chest x-rays increasing kVp and reducing mAs until quantum noise affects image quality. Copyright © 2012 Elsevier Ltd. All rights reserved.
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Radon measurements and dose estimate of workers in a manganese ore mine.
Shahrokhi, Amin; Vigh, Tamás; Németh, Csaba; Csordás, Anita; Kovács, Tibor
2017-06-01
In the new European Basic Safety Standard (EU-BSS), a new reference level for indoor radon concentration in workplaces has recommended that the annual average activity concentration of indoor radon shall not be higher than 300Bqm -3 . This paper describes the radon concentration level in an underground workplace (manganese ore mine) over long time intervals (4 years). Several common radon monitors devices - including NRPB and Raduet (as a passive method based on CR-39), AlphaGUARD PQ 2000Pro, SARAD EQF3220, TESLA and Pylon WLX (as active methods) - were used for continuous radon measurements. The output results were used, first, to comprised the result of each device, based on conditions present in underground mines; Second, to have comprehensive measurements about all factors that cause workers exposure to radiation (each monitoring device specified for a unique measurement). The results indicate that the mine's staff had successful efforts to reach the strict requirement of the new EU-BSS, and the average annual radon activity concentrations during the working hours were below 300Bqm -3 in the investigated period. The paper presents the effective dose calculations; applying different equilibrium factors suggested by the literature and calculated basing on our measurements at the site, concluding that the differences could be about threefold. Copyright © 2017 Elsevier Ltd. All rights reserved.
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A Role for MINIYO and QUATRE-QUART2 in the Assembly of RNA Polymerases II, IV, and V in Arabidopsis.
Li, Yaoxi; Yuan, Yuxiang; Fang, Xiaofeng; Lu, Xiuli; Lian, Bi; Zhao, Gaozhan; Qi, Yijun
2018-02-01
RNA polymerases IV and V (Pol IV and Pol V) are required for the generation of noncoding RNAs in RNA-directed DNA methylation (RdDM). Their subunit compositions resemble that of Pol II. The mechanism and accessory factors involved in their assembly remain largely unknown. In this study, we identified mutant alleles of MINIYO ( IYO ), QUATRE-QUART2 ( QQT2 ), and NUCLEAR RNA POLYMERASE B11/D11/E11 ( NRPB/D/E11 ) that cause defects in RdDM in Arabidopsis thaliana We found that Pol IV-dependent small interfering RNAs and Pol V-dependent transcripts were greatly reduced in the mutants. NRPE1, the largest subunit of Pol V, failed to associate with other Pol V subunits in the iyo and qqt2 mutants, suggesting the involvement of IYO and QQT2 in Pol V assembly. In addition, we found that IYO and QQT2 were mutually dependent for their association with the NRPE3 subassembly prior to the assembly of Pol V holoenzyme. Finally, we show that IYO and QQT2 are similarly required for the assembly of Pol II and Pol IV. Our findings reveal IYO and QQT2 as cofactors for the assembly of Pol II, Pol IV, and Pol V and provide mechanistic insights into how RNA polymerases are assembled in plants. © 2018 American Society of Plant Biologists. All rights reserved.
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Macías, M T; Navarro, T; Lavara, A; Robredo, L M; Sierra, I; Lopez, M A
2003-01-01
The radioisotope techniques used in molecular and cellular biology involve external and internal irradiation risk. The personal dosemeter may be a reasonable indicator for external irradiation. However, it is necessary to control the possible internal contamination associated with the development of these techniques. The aim of this project is to analyse the most usual techniques and to establish programmes of internal monitoring for specific radionuclides (32P, 35S, 14C, 3H, 125I and 131I). To elaborate these programmes it was necessary to analyse the radioisotope techniques. Two models have been applied (NRPB and IAEA) to the more significant techniques, according to the physical and chemical nature of the radionuclides, their potential importance in occupational exposure and the possible injury to the genetic material of the cell. The results allowed the identification of the techniques with possible risk of internal contamination. It was necessary to identify groups of workers that require individual monitoring. The risk groups have been established among the professionals exposed, according to different parameters: the general characteristics of receptor, the radionuclides used (the same user can work with one, two or three radionuclides at the same time) and the results of the models applied. Also a control group was established. The study of possible intakes in these groups has been made by urinalysis and whole-body counter. The theoretical results are coherent with the experimental results. They have allowed guidance to individual monitoring to be proposed. Basically, the document shows: (1) the analysis of the radiosotopic techniques, taking into account the special containment equipment; (2) the establishment of the need of individual monitoring; and (3) the required frequency of measurements in a routine programme.
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[Quality assurance in diagnostic radiology using an automated system. Experience and results].
Princivalli, M; Stea, L; Ordóñez, P L; Bussoli, L; Marchetti, C
1995-05-01
The authors report their personal experience with the use of an integrated quality control system in the radiology department. The system we used was the RTI DIGI-X Plus, a Swedish-made product, allowing a wide range of parameters to be measured on diagnostic X-ray units for general radiography, mammography and fluoroscopy. Data can be retrieved with a minimum number of measurements. The "oRTIgo" software improves the quality assurance system and ensures document compliance with international recommendations. The equipment consists of a detector unit, a processor and a display unit. The detector consists of a rotating holder with 12 combinations of metal filters of various thickness mounted in front of two photo-diodes covered with identical X-ray intensifying gadoliniumoxysulfide screens. This unit is connected to a data acquisition system controlled by a microcomputer. Peak tube voltage and total tube filtration are derived from the ratio of detector signals. The relationship between this ratio and the measured quantity is determined by a calibration procedure. Furthermore, exposure time "mAs" value, "mAs" linearity and exposure (or kerma in air) can be measured. Digital storage can be performed and input signals displayed. A serial interface is used to communicate with a PC for QC management purposes. An error propagation model is used to determine the inaccuracy of peak tube voltage measurements. With the DIGI-X Plus system, measurements can be carried out in a shorter time and the stored data reprocessed later on. After QA testing on 20 X-ray units in the radiology department, in vivo doses were measured using a TLD Harshaw 100 on 46 randomly selected patients undergoing chest examinations. The results are reported and analyzed following the NRPB protocol and show high agreement with the recommended values.
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NASA Astrophysics Data System (ADS)
Assi, Abed Al Nasser
2018-03-01
Reduction of the patient's received radiation dose to as low as reasonably achievable (ALARA) is based on recommendations of radiation protection organizations such as the International Commission on Radiological Protection (ICRP) and the National Radiological Protection Board (NRPB). The aim of this study was to explore the frequency and characteristics of rejected / repeated radiographic films in governmental and private centers in Jenin city. The radiological centers were chosen based on their high volume of radiographic studies. The evaluation was carried out over a period of four months. The collected data were compiled at the end of each week and entered into a computer for analysis at the end of study. Overall 5000 films (images) were performed in four months, The average repeat rate of radiographic images was 10% (500 films). Repetition rate was the same for both thoracic and abdominal images (42%). The main reason for repeating imaging was inadequate imaging quality (58.2%) and poor film processing (38%). Human error was the most likely reason necessitating the repetition of the radiographs (48 %). Infant and children groups comprised 85% of the patient population that required repetition of the radiographic studies. In conclusion, we have a higher repetition rate of imaging studies compared to the international standards (10% vs. 4-6%, respectively). This is especially noticeable in infants and children, and mainly attributed to human error in obtaining and processing images. This is an important issue that needs to be addressed on a national level due to the ill effects associated with excessive exposure to radiation especially in children, and to reduce cost of the care delivered.
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Reis, Pedro A A; Rosado, Gustavo L; Silva, Lucas A C; Oliveira, Luciana C; Oliveira, Lucas B; Costa, Maximiller D L; Alvim, Fátima C; Fontes, Elizabeth P B
2011-12-01
The molecular chaperone binding protein (BiP) participates in the constitutive function of the endoplasmic reticulum (ER) and protects the cell against stresses. In this study, we investigated the underlying mechanism by which BiP protects plant cells from stress-induced cell death. We found that enhanced expression of BiP in soybean (Glycine max) attenuated ER stress- and osmotic stress-mediated cell death. Ectopic expression of BiP in transgenic lines attenuated the leaf necrotic lesions that are caused by the ER stress inducer tunicamycin and also maintained shoot turgidity upon polyethylene glycol-induced dehydration. BiP-mediated attenuation of stress-induced cell death was confirmed by the decreased percentage of dead cell, the reduced induction of the senescence-associated marker gene GmCystP, and reduced DNA fragmentation in BiP-overexpressing lines. These phenotypes were accompanied by a delay in the induction of the cell death marker genes N-RICH PROTEIN-A (NRP-A), NRP-B, and GmNAC6, which are involved in transducing a cell death signal generated by ER stress and osmotic stress through the NRP-mediated signaling pathway. The prosurvival effect of BiP was associated with modulation of the ER stress- and osmotic stress-induced NRP-mediated cell death signaling, as determined in transgenic tobacco (Nicotiana tabacum) lines with enhanced (sense) and suppressed (antisense) BiP levels. Enhanced expression of BiP prevented NRP- and NAC6-mediated chlorosis and the appearance of senescence-associated markers, whereas silencing of endogenous BiP accelerated the onset of leaf senescence mediated by NRPs and GmNAC6. Collectively, these results implicate BiP as a negative regulator of the stress-induced NRP-mediated cell death response.
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Reis, Pedro A.A.; Rosado, Gustavo L.; Silva, Lucas A.C.; Oliveira, Luciana C.; Oliveira, Lucas B.; Costa, Maximiller D.L.; Alvim, Fátima C.; Fontes, Elizabeth P.B.
2011-01-01
The molecular chaperone binding protein (BiP) participates in the constitutive function of the endoplasmic reticulum (ER) and protects the cell against stresses. In this study, we investigated the underlying mechanism by which BiP protects plant cells from stress-induced cell death. We found that enhanced expression of BiP in soybean (Glycine max) attenuated ER stress- and osmotic stress-mediated cell death. Ectopic expression of BiP in transgenic lines attenuated the leaf necrotic lesions that are caused by the ER stress inducer tunicamycin and also maintained shoot turgidity upon polyethylene glycol-induced dehydration. BiP-mediated attenuation of stress-induced cell death was confirmed by the decreased percentage of dead cell, the reduced induction of the senescence-associated marker gene GmCystP, and reduced DNA fragmentation in BiP-overexpressing lines. These phenotypes were accompanied by a delay in the induction of the cell death marker genes N-RICH PROTEIN-A (NRP-A), NRP-B, and GmNAC6, which are involved in transducing a cell death signal generated by ER stress and osmotic stress through the NRP-mediated signaling pathway. The prosurvival effect of BiP was associated with modulation of the ER stress- and osmotic stress-induced NRP-mediated cell death signaling, as determined in transgenic tobacco (Nicotiana tabacum) lines with enhanced (sense) and suppressed (antisense) BiP levels. Enhanced expression of BiP prevented NRP- and NAC6-mediated chlorosis and the appearance of senescence-associated markers, whereas silencing of endogenous BiP accelerated the onset of leaf senescence mediated by NRPs and GmNAC6. Collectively, these results implicate BiP as a negative regulator of the stress-induced NRP-mediated cell death response. PMID:22007022
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Estimation of Soil Radon Concentration in Al-Qateef's Date Palm Farms, Saudi Arabia
DOE Office of Scientific and Technical Information (OSTI.GOV)
Al-Ghamdi, S. S.; Al-Garawi, M. S.; Baig, M. R.
2011-10-27
This study involves the measurement of radon concentrations in agricultural soil from two date Palm farms in Al-Qateef province using CR-39 detector. In each farm the palm trees are arranged in rows separated by the irrigation reservoirs. The first farm is about 10000 m{sup 2} and has 350 palm trees and the second farm is about 7000 m{sup 2} and has 320 palm trees. The average distance between trees is about 5.5 m. The rows are separated by an irrigation reservoir where fertilizers are added. Sixty soil samples were collected from each farm and classified in paperboard boxes. These samplesmore » were taken from different depths and positions between the trees and from the irrigation reservoir.A newly designed tag type dosimeter is used in which the alpha tracks are registered on both sides of the CR-39 detector. The tag dosimeter was calibrated against a cup type dosimeter which was calibrated at the National Radiological Protection Board (NRPB) at the U.K.The detectors were left to count for five months and then chemically treated in the standard way. Finally an optical microscope is used to count alpha tracks and the data are treated statistically.The study is set to test for significant differences in radon concentrations at different positions and depths in the barren and fertilized soils in the two farms. Measured radon concentrations ranged between 42 and 344Bq/m{sup 3}. No significant difference between the mean concentration values in soil samples taken between the trees and that taken at the depth of 50 cm from the irrigation reservoir. Significant difference was however found between radon concentrations in samples collected directly from the surface of the irrigation reservoir where fertilizers are introduced and those taken from the other two positions. The used fertilizers are found to have higher contents of uranium which is limited to the surface soil of the irrigation reservoir.« less
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Estimation of Soil Radon Concentration in Al-Qateef's Date Palm Farms, Saudi Arabia
NASA Astrophysics Data System (ADS)
Al-Ghamdi, S. S.; Al-Garawi, M. S.; Baig, M. R.; Al-Sameen, M.
2011-10-01
This study involves the measurement of radon concentrations in agricultural soil from two date Palm farms in Al-Qateef province using CR-39 detector. In each farm the palm trees are arranged in rows separated by the irrigation reservoirs. The first farm is about 10000 m2 and has 350 palm trees and the second farm is about 7000 m2 and has 320 palm trees. The average distance between trees is about 5.5 m. The rows are separated by an irrigation reservoir where fertilizers are added. Sixty soil samples were collected from each farm and classified in paperboard boxes. These samples were taken from different depths and positions between the trees and from the irrigation reservoir. A newly designed tag type dosimeter is used in which the alpha tracks are registered on both sides of the CR-39 detector. The tag dosimeter was calibrated against a cup type dosimeter which was calibrated at the National Radiological Protection Board (NRPB) at the U.K. The detectors were left to count for five months and then chemically treated in the standard way. Finally an optical microscope is used to count alpha tracks and the data are treated statistically. The study is set to test for significant differences in radon concentrations at different positions and depths in the barren and fertilized soils in the two farms. Measured radon concentrations ranged between 42 and 344Bq/m3. No significant difference between the mean concentration values in soil samples taken between the trees and that taken at the depth of 50 cm from the irrigation reservoir. Significant difference was however found between radon concentrations in samples collected directly from the surface of the irrigation reservoir where fertilizers are introduced and those taken from the other two positions. The used fertilizers are found to have higher contents of uranium which is limited to the surface soil of the irrigation reservoir.
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An assessment of the radiological impact of the Windscale reactor fire, October 1957.
Crick, M J; Linsley, G S
1984-11-01
On the 10th and 11 October 1957 a fire in the No 1 Pile at the Windscale establishment in Cumbria led to an uncontrolled release of activity to the atmosphere. The resultant cloud subsequently dispersed and radionuclides could be detected over England, Wales and parts of northern Europe. The extensive environmental measurements which were made during and after the release enabled a fairly accurate estimate to be made of the radiation doses to the most exposed individuals in the local population. Until recently, no estimates of the population dose resulting from the release had been published. This paper describes assessments which have been made by the NRPB of the population or collective dose from the release and of the possible associated health impact. In addition to the fission products that escaped, radionuclides were released from materials undergoing irradiation in the pile at the time of the fire. The assessment has included the results of a review of previously unpublished data which established the quantity of these nuclides released and considers their impact on both individual and population doses. The collective effective dose equivalent commitment from the release is estimated to have been 2.0 x 10(3) man Sv. The route of exposure which contributed the most to the collective dose was the inhalation pathway. Iodine-131 was the most important radionuclide, contributing nearly all of the collective dose to the thyroid and a large part of the collective effective dose. Polonium-210 and caesium-137 also made significant contributions; that from caesium-137 came in the longer term via external irradiation from ground deposits and the ingestion of contaminated foodstuffs. The methodology used in the study has been validated to a certain degree by comparing the predicted levels of individual thyroid activity and those measured directly in the weeks following the accident in London, Leeds and Cumbria.
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Hormann, Volker; Kirchner, Gerald
2002-04-22
For agriculturally used areas, which are contaminated by the debris from a nuclear accident, the use of chemical amendmends (e.g. potassium chloride and lime) is among the most common soil-based countermeasures. These countermeasures are intended to reduce the plant uptake of radionuclides (mainly 137Cs and 90Sr) by competitive inhibition by chemically similar ions. So far, the impacts of countermeasures on soil solution composition - and thus, their effectiveness - have almost exclusively been established experimentally, since they depend on mineral composition and chemical characteristics of the soil affected. In this study, which focuses on caesium contamination, the well-established code PHREEQC was used as a geochemical model to calculate the changes in the ionic compositions of soil solutions, which result from the application of potassium or ammonium in batch equilibrium experiments. The simple ion exchange model used by PHREEQC was improved by taking into account selective sorption of Cs+, NH4+ and K+ by clay minerals. Calculations were performed with three different initial soil solution compositions, corresponding to particular soil types (loam, sand, peat). For loamy and sandy soils, our calculational results agree well with experimental data reported by Nisbet (Effectiveness of soil-based countermeasures six months and one year after contamination of five diverse soil types with caesium-134 and strontium-90. Contract Report NRPB-M546, National Radiation Protection Board, Chilton, 1995.). For peat, discrepancies were found indicating that for organic soils a reliable set of exchange constants of the relevant cations still has to be determined experimentally. For cesium, however, these discrepancies almost disappeared if selective sites were assumed to be inaccessible. Additionally, results of sensitivity analyses are presented by which the influence of the main soil parameters on Cs+ concentrations in solution after soil treatment has been systematically studied. It is shown that calculating the impacts of soil-based chemical countermeasures on soil solution chemistry using geochemical codes such as PHREEQC offers an attractive alternative to establishing these impacts by often time-consuming and site-specific experiments.
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NASA Astrophysics Data System (ADS)
Cucos Dinu, Alexandra; Baciu, Calin; Dicu, Tiberius; Papp, Botond; Moldovan, Mircea; Bety Burghele, Denissa; Tenter, Ancuta; Szacsvai, Kinga
2017-04-01
Exposure to radon in homes and workplaces is now recognized as the most important natural factor in causing lung cancer. Radon activity is usually higher in buildings than in the outside atmosphere, as it may be released from building materials and soil beneath the constructions, and the concentration builds-up indoor, due to the low air renewal rates. Indoor radon levels can vary from one to multiple orders of magnitude over time and space, as it depends on several natural and anthropogenic factors, such us the radon concentration in soil under the construction, the weather conditions, the degree of containment in the areas where individuals are exposed, building materials, outside air, tap water and even city gas, the architecture, equipment (chimney, mechanical ventilation systems, etc.), the environmental parameters of the building (temperature, pressure, etc.), and on the occupants' lifestyle. The study presents the distribution of indoor radon in Transylvania, Romania, together with the measurements of radon in soil and soil water. Indoor radon measurements were performed by using CR-39 track detectors exposed for 3 months on ground-floor level of dwellings, according to the NRPB Measurement Protocol. Radon concentrations in soil and water were measured using the LUK3C device. A complete map was plotted at the date, based on 3300 indoor radon measurements, covering an area of about 42% of the Romanian territory. The indoor radon concentrations ranged from 5 to 3287 Bq m-3, with an updated preliminary arithmetic mean of 179 Bq m-3, and a geometric mean of 122 Bq m-3. In about 11% of the investigated grid cells the indoor radon concentrations exceed the threshold of 300 Bq m-3. The soil gas radon concentration varies from 0.8 to 169 kBq m-3, with a geometric mean of 26 kBq m-3. For water samples, the results show radon concentrations within the range of 0.3 - 352.2 kBq m-3, with a geometric mean of 7.7 Bq L-1. A weak correlation between the three sets of values (residential, soil, water) was observed, both as individual values, average values over the grid or county level. The highest concentrations of indoor radon were found in Bihor, Mures, Brasov, and Cluj. In these regions further investigation is needed on the factors influencing the accumulation of radon in high concentrations in indoor air, such as soil type and geology, ventilation, or constructive and architectural features. Acknowledgements: The research is supported by the project ID P_37_229, Contract No. 22/01.09.2016, with the title „Smart Systems for Public Safety through Control and Mitigation of Residential Radon linked with Energy Efficiency Optimization of Buildings in Romanian Major Urban Agglomerations SMART-RAD-EN" of the POC Programme.
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NASA Astrophysics Data System (ADS)
Talbot, Lee
1999-03-01
The European Union's Basic Safety Standards Directive (96/29/Euratom) lays down safety standards for the protection of workers and the general public against the effects of ionising radiations. Article 42 of the Directive deals with the protection of aircrew. It states that for crew of jet aircraft who are likely to be subject to exposure to more than 1 mSv y-1 appropriate measures must be taken, in particular: to assess the exposure of the crew concerned, to take into account the assessed exposure when organising working schedules with a view to reducing the doses of highly exposed aircrew, to inform concerned workers of the health risks involved in their work, to apply Article 10 to female aircrew. (The unborn child shall be treated like a member of the public.) This Directive must be transformed into national law of the 15 member states of the European Union by 13 May 2000. The European Commission and the Radiological Protection Institute of Ireland sponsored this International Conference. The objective of this conference was to assist both the airline industry and the national regulatory organisations in identifying the means available to comply with the requirements of the Directive. Over 200 delegates attended the conference from more than 25 countries. The welcoming addresses were made by Mary Upton (Director of the Radiological Protection Institute of Ireland), Joe Jacob (Minister for State responsible for Nuclear Safety) and James Currie (Director-General for the Environment, Nuclear Safety and Civil Protection). Mr Currie stated that there was a need for political decisions to be based on good science, and that technological trends will lead to higher and longer flights, and therefore higher radiation doses. The first day concentrated on the scientific basis of measurement, calculation and monitoring of cosmic radiation. The first speaker, Dr Heinrich from the University of Siegen, Germany, talked about the physics of cosmic radiation fields. He pointed out that of all the particles that come from outside our solar system 85% are hydrogen, 12.5% are helium and 1.5% are heavier particles. The flux of these particles changes over the 11-year solar cycle: if the solar activity is high then the cosmic radiation flux is low. The Earth's geomagnetic field affects whether or not a particle will reach the Earth. The nearer the equator, the higher the cut-off rigidity and hence the greater the shielding. At the poles the cut-off rigidity is at its lowest, hence the greater the number of particles which reach the Earth. The speaker summarised by saying that in order to make an accurate assessment of the radiation dose due to cosmic radiation one must know which primary cosmic rays are involved, the solar modulation effects, the geomagnetic shielding and particle interactions in the atmosphere. Alternatively dosimetric measurements can be made at different altitudes, latitudinal and longitudinal positions for the most relevant radiation components. The second speaker of the morning, Dr Hilton Smith, the Ex-Scientific Secretary of the ICRP, gave a talk entitled `Quantifying Radiation Risk'. The talk started by explaining that high LET radiations have a greater probability of causing DNA damage than low LET radiations and that DNA can be damaged in a number of ways: the single-strand break, two single-strand breaks, the double-strand break (the hallmark of ionising radiation) and base damage. The possible effects of these interactions are the death of the cell, inhibition of cellular division and change in cell structure. The physical and chemical effects occur over very short periods, but the biological effects may not be noticed for many years. The speaker described risk estimation based on A-bomb survivors, medical therapy, medical diagnosis of patients, occupational studies of uranium miners and radium workers. The human fatal cancer risk has been calculated by the ICRP to be 5% Sv-1 for the public. The maximum likelihood of cancer occurring is at age 70. At the end of the presentation there was a discussion on whether or not protons of a certain energy should have a quality factor of 5. It was suggested that the factor should be equal to one. Dr Bartlett of the NRPB gave the next talk on Radiation Protection Concepts and Quantities for Occupational Exposure to Cosmic Radiation. Dr Bartlett explained that there are significant differences between the exposure condition of aircrew and occupational exposure generally. There are a greater range of radiation types and energies. Half of aircrews' doses are due to neutrons. UK Classified radiation workers receive 2% of their dose from high LET radiations and aircrew receive 50%. Dose distributions and characteristics of the working populations are different, with 53% of aircrew being female, as opposed to 7% of Classified UK radiation workers. The field intensity on aircraft is predictable, and, with the exception of rare solar flare events, there is no risk of accidental exposures. The speaker highlighted the variation in cosmic radiation dose as a function of altitude illustrated by the radiation doses at 15, 10 and 6.7 km being 10, 5 and 1 µSv h-1. It was interesting to note the comparison made between the average radiation dose of 1 mSv y-1 in the nuclear industry and 2 mSv y-1 for aircrew. The speaker said that it is necessary to appreciate that people living in high radon areas in the UK receive approximately 8 mSv per year. Dr Bartlett highlighted how the requirements for the protection of aircrew from the Basic Safety Standard Directive (BSS96) differed from those for occupational exposures in general, namely that there are not explicit dose limits, other than that to be applied to the exposure of the foetus. There are no requirements for the designation of areas or classification of workers and there is no reference to the principle of ALARA, but there is a requirement to take account of the assessed exposure when arranging work schedules with a view to reducing higher doses. Dr Bartlett summed up by saying that dose assessment will probably be done by folding roster information with estimates of route doses. The last speaker of the morning session was Dr Maria Blettner, from the International Agency for Research on Cancer, Lyon, France. She talked about epidemiological studies for individuals occupationally exposed to radiation. The speaker emphasised that the results of early studies regarding cancer mortality are equivocal; elevated cancer risks have been observed in some studies, but not in others. The low cumulative dose up to 100 mSv is associated with poor statistics. Therefore it is difficult to calculate the relative risk of exposure with a high degree of confidence. The speaker also highlighted the difficulty in obtaining a comparison population since aircrews have characteristics and lifestyles that differ from the general population. The speaker stressed the need for large studies in this field of epidemiology. Dr Blettner summarised her speech by saying that the results of a cohort of some 22 000 pilots and 47 000 crewmembers can be formed from the workers in nine different countries and that pooled analyses are expected in 2001. The next speaker was Dennis O'Sullivan, from the Dublin Institute of Advanced Studies, who gave a talk entitled `Overview and Present Status of EC Research Programme'. The objectives of the EC programme were highlighted as follows: to develop and calibrate instrumentation for use at altitude, to measure flux and energy spectra of neutrons and charged particles, to measure LET spectra and ambient dose equivalent, to estimate dose contribution by solar particle events and finally to compare results with calculations. The airlines involved in these studies were Aer Lingus, Alitalia, BA, Lufthansa and Scandinavia Airlines. Tests were carried out on several routes, on both subsonic and supersonic aircraft. A detailed set of measurements were obtained over a five-year period. Professor O'Sullivan said that the NRPB used TLDs for low and high LET radiations and PADC for neutrons. The investigation of dosemeter response was carried out using Monte Carlo codes. The active instruments used for measurements were the tissue equivalent proportional counter (TEPC) and a Bonnersphere spectrometer using eight spheres. The instrumentation used was calibrated in the CERN-CEC reference field. In summary, it was found that the shape of the neutron spectrum does not change with altitudes and that the maximum dose rate was found to be under the seats of the aircraft. Dr Lindbourg of the Swedish Radiation Protection Institute gave a short talk on the importance of using the TEPC for cosmic ray measurements, as it is the only means of reading directly absorbed dose to tissue and the radiation quality (in terms of lineal energy). Dr Schewe from PTB, Germany, gave the next talk on reference fields and calibration procedures. The speaker highlighted the difficulties in measuring radiation fields onboard aircraft, as the calibration fields used are often vastly different to the radiation field the instrumentation is being exposed to. The speaker said that this could lead to errors in the measurements in excess of 50%. One way around this is to use realistic reference fields, which produce similar particle compositions and particle fluences as those present in the cosmic radiation at aircraft altitudes. For this work the reference field facility in one of the secondary beams lines of the CERN Super Proton Synchrotron was used. In summary it was shown that the TEPC could be used as a reference instrument for evaluating ambient dose equivalent in aircraft. The next speaker was Dr Tommasino of the ANPA, Rome, who talked about in-flight measurement of radiation fields and doses. He stated that the problem of radiation dose assessment has been developed within the multinational research programmes of the Commission of the European Communities. The speaker talked about the different dosimetric systems formed by the TEPC, ANPA-stack, DIAS-stack and Extended Rem-counter. The ANPA-stack and DIAS-stack detectors have been developed under the CEC research programme specifically for the measurement of cosmic radiation on aircraft. The experiments were carried out between 1994 and 1997 at the period of the solar minimum, and therefore represent an upper limit on the dose due to galactic cosmic rays. The speaker gave an example of a flight from Tokyo to Milan, where the ambient dose equivalent was 4.83 µSv h-1 and the annual dose, assuming a 700 hour year, was 3.38 mSv y-1. In conclusion the speaker said that the measurements from all four dosimetric systems were consistent. Dr Schraube from the National Research Centre for Environment and Health, Germany, gave the last presentation of the day, on the experimental verification and calculation of route doses. The verification was restricted to neutrons. The speaker showed that theoretical calculations could be matched to experimental data. Therefore the fluences at all positions of interest in the Earth's atmosphere could be calculated. It was then possible to calculate the doses on aviation routes using the computer package European Program for the Calibration of Aviation Route Dose (EPCARD). The second day of the conference concentrated on the airline industry perspective of the cosmic radiation problem. The first speaker was B Lecouturier, of the Federation des Syndicats de Transport, Brussels. She gave an introductory presentation on the view of cabin crew. The speaker highlighted the inconsistency of some EU states: for example, some states insist that pregnant workers stop flying, while others do not. In conclusion the speaker said that cabin crew wish for a correct assessment of their cosmic radiation dose, medical surveillance and further epidemiological studies. The second speaker of the day was Dr Balouet, also from the Federation des Syndicats de Transport, Brussels. His talk was entitled, `Ionising Radiations and Cabin Crew Concerns'. The main concerns of cabin crews were as follows: uncertainty in the quality factor for neutrons, heavy ions are not taken into account when calculating radiation doses, 25-60% of some routes if flown for a standard working year could exceed the 6 mSv level, European crew flying on non-European airlines, solar flares, which give relatively high radiation exposures. The next speaker was Wallace Friedberg of the Civil Aeromedical Institute, USA, who gave a talk on the guidelines provided by the FAA to promote radiation safety for Air Carrier Crewmembers. Wallace recalled the information the FAA has provided, including: (a) guidelines for air carrier training programmes on in-flight radiation exposure, including recommended radiation exposure limits; (b) estimates of the galactic radiation dose received on a wide variety of air carrier flights; (c) tables for estimating healthy risks from galactic radiation exposure; and (d) support for research on the effects of irradiation during pregnancy, including possible galactic radiation effects on the reproductive health of female flight attendants. The speaker highlighted the availability of a computer program (CARI) available to the general public, which can be used for estimating the galactic radiation dose received from a non-stop flight between any two locations in the world. Sandy Mitchell of the European Cockpit Association was the next speaker. He gave a talk on the concept of `As Low as Reasonably Achievable' in relation to cosmic radiation. The speaker began by saying that aviation activity was increasing by 5% per annum and flights below 25 000 ft pose no radiation exposure problem. The speaker then drew attention to the strategies that could be employed to reduce radiation exposure, which include restriction of altitude to 31 000 ft, restriction of annual flying hours to 500 hours, increased aircraft shielding, fitting all aircraft with active monitoring and the introduction of annual medical examinations for aircrew. It was also suggested by the speaker that pregnant flying aircrew could undertake ground duties or be given unpaid leave. Alternatively, they could be transferred to regional routes where doses are very low. The speaker concluded by performing a cost-benefit analysis of reducing the cruising altitude of aircraft. This lead to increased fuel consumption but reduced collective dose. It was shown that the collective dose reduction would not be great enough to justify the costs incurred. The session after lunch concentrated on the airlines and the air industry. Dr Oksanen of Finnair gave the fist lecture of this session in a talk entitled `The Operator: Experiences and Views'. The speaker began by summarising the Association of European Airlines (AEA) involvement in cosmic radiation, which has included dose measurement and estimation, production of educational material and epidemiological studies. The speaker talked about the differing methods of route dose estimation using active monitoring, passive monitoring and computer modelling. The AEA airlines believe that the EURATOM Directive may best be implemented by route dose estimation using a common mathematical model. This would have the advantage that modelling is accepted worldwide as a credible and practical method of dose estimates and overcomes the logistic problems, the likelihood of equipment failure and error inherent in direct measurement. In addition, it allows for consistency of route dose estimates among various airlines and finally offers the opportunity for independent scrutiny and audit required. Michael Bagshaw, the Head of Medical Services for British Airways, gave a very interesting talk on in-flight measurements. Mr Bagshaw began by talking about the cosmic ray detection methods used on the Concorde, consisting of GM tubes and boron trifluoride detectors. The information from these detectors is then fed directly to the pilot. The system alarms at 500 µSv h-1. However, since Concorde entered service in 1976 no Concorde has had to reduce altitude due to cosmic radiation. Mr BAGSHAW said the effective dose when averaged over 113 flights was 13 µSv h-1, with the London to New York route dose being 43 µSv h-1. On average flight crew get 3-4 mSv y-1 and cabin crews get 2-3 mSv y-1. Interestingly, it is BA policy to ground crew on the declaration of pregnancy. A crewmember who does not declare she is pregnant may still fly, even if she knows she is pregnant. A pregnant crewmember therefore has a choice. Christopher Hume from British Aerospace gave a short presentation regarding the manufacturer's perspective. A number of issues that are going to increase cosmic radiation dose were highlighted. Future aircraft are going to fly at much higher altitudes, the BIZ JET is going to fly at 60 000 ft and the SCT is going to fly at 70 000 ft. Some new routes may go directly over the North Pole. The speaker mentioned that shielding of the aircraft in order to reduce doses was impractical. Clive Dyer from the DERA Space Department in Farnborough made an unscheduled and very interesting presentation concerning the cosmic radiation effects on avionics. He stated that there are common links between the interaction of radiation within electronics and that within tissue at the DNA level. His talk described the different ways in which ionising radiation can interact with electronics and cause a number of different effects, including bit-flips, destructive burn-out, gate rupture and dielectric failure. Professor Dyer mentioned that the reduction in component size means larger upsets in the electronics. The speaker then concentrated on single-event effects on equipment in space, where the problems were first predicted in 1962 and observed in 1975. PCs on the Space Shuttle and Mir require frequent reboot, typically every nine hours. The speaker concluded by saying that single-event effects can now be seen at ground level because of the design of modern computer chips. The final day concentrated on regulatory aspects. L Bergau, from the Medical Department of Lufthansa German Airlines, gave the first talk on medical aspects. His study involved the comparison of female aircrew and female ground crew. The study excluded anyone who had undergone medical treatment with ionising radiation and heavy smokers. Two thousand cells from each individual were scored. The results showed that the numbers of dicentrics were the same in the cabin crew, aircrew and ground crew, demonstrating that the low cosmic radiation exposures seem not to increase cancer risk. Mr Ulback from the National Institute of Radiation Hygiene, Denmark, gave the next speech. His talk was simply entitled `Radiation Protection'. The speaker outlined how the legislation had been derived from the ICRP, through the EU commission and EU council, and finally adopted in the legislation of the member states. The final speaker, Mr Courades from the European Commission, spoke about EU legislation. Mr Courades said that the EU Directive would affect more states than are currently members because other countries wish to become part of the EU. It was highlighted that Article 42 applied only to aircrew (civilian and military) and not passengers. It was also pointed out that classification of the workplace is not required onboard aircraft. Mr Courades said that it was difficult to have a generic dose for a specific flight because of `free flight' where an aircraft changes altitude frequently. The speaker summed up by stressing the need for a common implementation of the directive.