Climate change and landscape development in post-closure safety assessment of solid radioactive waste disposal: Results of an initiative of the IAEA.

The International Atomic Energy Agency has coordinated an international project addressing climate change and landscape development in post-closure safety assessments of solid radioactive waste disposal. The work has been supported by results of parallel on-going research that has been published in a variety of reports and peer reviewed journal articles. The project is due to be described in detail in a forthcoming IAEA report. Noting the multi-disciplinary nature of post-closure safety assessments, here, an overview of the work is given to provide researchers in the broader fields of radioecology and radiological safety assessment with a review of the work that has been undertaken. It is hoped that such dissemination will support and promote integrated understanding and coherent treatment of climate change and landscape development within an overall assessment process. The key activities undertaken in the project were: identification of the key processes that drive environmental change (mainly those associated with climate and climate change), and description of how a relevant future may develop on a global scale; development of a methodology for characterising environmental change that is valid on a global scale, showing how modelled global changes in climate can be downscaled to provide information that may be needed for characterising environmental change in site-specific assessments, and illustrating different aspects of the methodology in a number of case studies that show the evolution of site characteristics and the implications for the dose assessment models. Overall, the study has shown that quantitative climate and landscape modelling has now developed to the stage that it can be used to define an envelope of climate and landscape change scenarios at specific sites and under specific greenhouse-gas emissions assumptions that is suitable for use in quantitative post-closure performance assessments. These scenarios are not predictions of the future, but are projections based on a well-established understanding of the important processes involved and their impacts on different types of landscape. Such projections support the understanding of, and selection of, plausible ranges of scenarios for use in post-closure safety assessments.

Surveillance and Outbreak Response Management System (SORMAS) to support the control of the Ebola virus disease outbreak in West Africa.

In the context of controlling the current outbreak of Ebola virus disease (EVD), the World Health Organization claimed that 'critical determinant of epidemic size appears to be the speed of implementation of rigorous control measures', i.e. immediate follow-up of contact persons during 21 days after exposure, isolation and treatment of cases, decontamination, and safe burials. We developed the Surveillance and Outbreak Response Management System (SORMAS) to improve efficiency and timeliness of these measures. We used the Design Thinking methodology to systematically analyse experiences from field workers and the Ebola Emergency Operations Centre (EOC) after successful control of the EVD outbreak in Nigeria. We developed a process model with seven personas representing the procedures of EVD outbreak control. The SORMAS system architecture combines latest In-Memory Database (IMDB) technology via SAP HANA (in-memory, relational database management system), enabling interactive data analyses, and established SAP cloud tools, such as SAP Afaria (a mobile device management software). The user interface consists of specific front-ends for smartphones and tablet devices, which are independent from physical configurations. SORMAS allows real-time, bidirectional information exchange between field workers and the EOC, ensures supervision of contact follow-up, automated status reports, and GPS tracking. SORMAS may become a platform for outbreak management and improved routine surveillance of any infectious disease. Furthermore, the SORMAS process model may serve as framework for EVD outbreak modeling.

Impact of liver cirrhosis on liver enhancement at Gd-EOB-DTPA enhanced MRI at 3 Tesla.

PURPOSE: The purpose of this study was to assess differences in enhancement effects of liver parenchyma between normal and cirrhotic livers on dynamic, Gd-EOB-DTPA enhanced MRI at 3T. MATERIALS AND METHODS: 93 patients with normal (n=54) and cirrhotic liver (n=39; Child-Pugh class A, n=18; B, n=16; C, n=5) underwent contrast-enhanced MRI with liver specific contrast media at 3T. T1-weighted volume interpolated breath hold examination (VIBE) sequences with fat suppression were acquired before contrast injection, in the arterial phase (AP), in the late arterial phase (LAP), in the portal venous phase (PVP), and in the hepatobiliary phase (HBP) after 20 min. The relative enhancement (RE) of the signal intensity of the liver parenchyma was calculated for all phases. RESULTS: Mean RE was significantly different among all evaluated groups in the hepatobiliary phase and with increasing severity of liver cirrhosis, a decreasing, but still significant reduction of RE could be shown. Phase depending changes of RE for each group were observed. In case of non-cirrhotic liver or Child-Pugh Score A cirrhosis mean RE showed a significant increase between AP, LAP, PVP and HBP. For Child-Pugh B+C cirrhosis RE increased until PVP, however, there was no change in case of B cirrhosis (p=0.501) and significantly reduced in case of C cirrhosis (p=0.043) during HBP. CONCLUSION: RE of liver parenchyma is negatively affected by increased severity of liver cirrhosis, therefore diagnostic value of HBP could be limited in case of Child Pugh B+C cirrhosis.

Potential consequences of the Fukushima accident for off-site nuclear emergency management: a case study for Germany.

The Fukushima accident led to high radionuclide releases into the atmosphere for more than 3 weeks. This situation has not been assumed when the concepts of nuclear emergency preparedness were developed internationally. The results of simulations studying potential implications of Fukushima-like source terms on nuclear emergency preparedness are presented. Two hypothetical source terms are considered. Radiological consequences are assessed with the decision support system RODOS. Atmospheric dispersion calculations are based on meteorological monitoring data from June and December 2010, respectively, to study potential seasonal effects. Simulations are performed for two nuclear power plant sites in Northern and Southern Germany, respectively. These sites are chosen due to their differing meteorology and topography. Predicted radiation doses of members of the population are compared with dose reference levels actually recommended for initiating protective measures in Germany. Potential implications of general interest for nuclear emergency planning are discussed.

[Secondary sclerosing cholangitis after multiple trauma and long-term intensive care treatment: case report of a characteristic course]. / Sekundär-sklerosierende Cholangitis nach Polytrauma und Langzeitintensivtherapie : Fallbericht eines charakteristischen Verlaufs.

This article reports on a patient who needed intensive care treatment because of multiple trauma. The patient had no preexisting liver disease but developed secondary sclerosing cholangitis and finally died. The etiology, diagnosis and therapeutic options of this clinical picture are discussed and a review of the literature is presented.

Radioactivity from Fukushima Dai-ichi in air over Europe; part 1: spatio-temporal analysis.

Radionuclides emitted from the Fukushima I nuclear power plant have been detected in air all over Europe. Concentrations remained far below levels which could have caused radiological concern: probably the committed thyroid dose due to inhalation remained below about 1 µSv (for 10 y children), within the investigated region. They provided, however, a spatio-temporal signal which could be used to develop and test tools to provide additional information on the large-scale situation (Europe-wide, in this case) during a nuclear emergency. In this part we discuss the spatial distribution of the contaminated air masses over Europe. Using (131)I as an example, we present a method to construct maps of the time-cumulated (131)I concentration in air and of the peak concentrations. Procedures to deal with the statistical limitations of a data set stemming from different monitoring schemes are discussed. As over all results, the mean (over the investigated region) cumulated concentration of particular (131)I is estimated about 9 mBq d/m(3), with observed maximum of about 23 mBq d/m(3). The probability that much higher concentrations occurred at unsampled locations, than have been observed anywhere, is assessed low, e.g. about 2.5% for the cumulated (131)I(part.) concentration to exceed 30 mBq d/m(3). Our method can be used in nuclear emergencies for providing spatial analyses if radionuclide concentrations of health concern are detected by atmospheric monitoring stations. We suggest considering such methods of data harmonization if synoptic assessment based on heterogeneous datasets is attempted.

Radioactivity from Fukushima Dai-ichi in air over Europe; part 2: what can it tell us about the accident?

It is shown which information can be extracted from the monitoring of radionuclides emitted from the Fukushima Dai-ichi nuclear power plant and transported to Europe. In this part the focus will be on the analysis of the concentration ratios. While (131)I, (134)Cs and (137)Cs were reported by most stations, other detected radionuclides, reported by some, are (95)Nb, (129m)Te, (132)Te, (132)I, (136)Cs and (140)La. From their activity ratios a mean burn-up of 26.7 GWd/t of the fuel from which they originated is estimated. Based on these data, inventories of radionuclides present at the time of the accident are calculated. The caesium activity ratios indicate emissions from the core of unit 4 which had been unloaded into the fuel storage pool prior to the accident.

Giant cell hepatitis: an unusual cause of fulminant liver failure.

Giant cell hepatitis is a very rare disease of unknown origin. It has been hypothesized that drugs, viral infections, or autoimmune reactions may play a pathogenetic role. Here, we describe a 33 year old patient with bacterial bronchitis who was treated with doxycycline (100 mg/d) for one week. Furthermore the patient complained of malaise and a distinct jaundice. Liver parameters increased dramatically (AST 4670 U/l, ALT 5350 U/l, bilirubin 226 µmol/l) and liver function was impaired (INR = 1,45). The ultrasound scan showed a hepatomegaly with no signs of cirrhosis, normal spleen size and normal bile ducts; liver perfusion was normal. No evidence of Wilson's disease, hemochromatosis, autoimmune hepatitis, primary sclerosing cholangitis, primary biliary cirrhosis, hepatitis A, B, C and E, HIV, CMV, VZV, adenoviral infections, or paracetamol intoxication was found. Subsequently, the patient developed acute liver failure (AST 2134 U/l, ALT 2820 U/l, bilirubin 380 µmol/l, INR 3.0) and a beginning renal failure. Therefore, he was transferred to our transplant center. Due to increasing confusion and somnolence due to cerebral edema mechanical ventilation was needed. Because of an acute renal failure and severe hepatic encephalopathia MARS-hemodialysis was performed. Three weeks after the appearance of the jaundice he underwent liver transplantation (MELD 40). Surprisingly, in the explanted liver the diagnosis of giant cell hepatitis was made. Today--2 years after successful liver transplantation--the patient is in very good condition with normal liver function. In conclusion, giant cell hepatitis is a rare cause of acute liver failure that is often recognized only histologically.

Observations and modelling of thoron and its progeny in the soil-atmosphere-plant system.

Samples of pasture vegetation, mainly Trifolium pratensis, were collected at the Botanic Garden of the University of Bologna during the period 1998-2000 and measured by gamma-spectrometry for determining thoron progeny. Concentrations of (212)Pb were between 1.5 and 20 Bq m(-2), with individual peaks up to 70 Bq m(-2). Soil samples were collected at the same location and physically characterised. Their chemical composition (particularly Th and U) was determined by X-ray fluorescence spectroscopy. Lead-212 on plants mainly originates from dry and wet deposition of this isotope generated in the lower atmosphere by the decay of its short-lived precursor (220)Rn, which is produced in the upper soil layers as a member of the natural thorium decay chain and exhales into the atmosphere. Concentrations of (220)Rn in the atmosphere depend on (1) the amount of Th present in soil, (2) the radon fraction which escapes from the soil minerals into the soil pore space, (3) its transport into the atmosphere, and (4) its redistribution within the atmosphere. The mobility of radon in soil pore space can vary by orders of magnitude depending on the soil water content, thus being the main factor for varying concentrations of (220)Rn and (212)Pb in the atmosphere. We present a simple model to predict concentrations of thoron in air and its progeny deposited from the atmosphere, which takes into account varying soil moisture contents calculated by the OPUS code. Results of this model show close agreement with our observations.

[Hepatic trauma. Interventional and conservative therapy]. / Lebertrauma. Interventionelle und konservative Therapie.

The non-operative management of hemodynamically stable patients with liver trauma has become the standard of care. Non-operative treatment has a success rate of >80%. In the majority of cases of hemodynamic instability or high grade liver injuries, however, a surgical approach is necessary. As for conservative treatment of liver trauma the surveillance of patients in the ICU is of utmost importance. Repeat CT scans are only necessary in patients with high grade injuries or in case of complications. Interventional procedures, such as the endoscopic retrograde cholangiopancreatography in cases of biliary complications or angiography for vascular complications, are increasingly being used in order to avoid surgery. The success rates of non-operative strategies have been improving continuously over the last decades.

A new approach to estimate nuclide ratios from measurements with activities close to background.

Measurements of low-level radioactivity often give results of the order of the detection limit. For many applications, interest is not only in estimating activity concentrations of a single radioactive isotope, but focuses on multi-isotope analyses, which often enable inference on the source of the activity detected (e.g. from activity ratios). Obviously, such conclusions become questionable if the measurement merely gives a detection limit for a specific isotope. This is particularly relevant if the presence of an isotope, which shows a low signal only (e.g. due to a short half-life or a small transition probability), is crucial for gaining the information of interest. This paper discusses a new approach which has the potential to solve these problems. Using Bayesian statistics, a method is presented which allows statistical inference on nuclide ratios taking into account both prior knowledge and all information collected from the measurements. It is shown that our method allows quantitative conclusion to be drawn if counts of single isotopes are low or become even negative after background subtraction. Differences to the traditional statistical approach of specifying decision thresholds or detection limits are highlighted. Application of this new approach is illustrated by a number of examples of environmental low-level radioactivity measurements. The capabilities of our approach for spectrum interpretation and source identification are demonstrated with real spectra from air filters, sewage sludge and soil samples.

Uncertainties in radioecological assessment models--their nature and approaches to reduce them.

Radioecological assessment models are necessary tools for estimating the radiation exposure of humans and non-human biota. This paper focuses on factors affecting their predictive accuracy, discusses the origin and nature of the different contributions to uncertainty and variability and presents approaches to separate and quantify them. The key role of the conceptual model, notably in relation to its structure and complexity, as well as the influence of the number and type of input parameters, are highlighted. Guidelines are provided to improve the degree of reliability of radioecological models.

A prospective cross-over study comparing the pharmacokinetics of cyclosporine A and its metabolites after oral versus short-time intravenous cyclosporine A administration in pre-heart transplant patients.

Sometimes intravenous administration of cyclosporine (CsA) is essential before oral administration is possible. There are only a few reports available on the interindividual variability of CsA metabolism and different metabolite pattern depending on intravenous versus oral administration of CsA in heart transplant (HTx) patients. For effective inhibition of calcineurin we used a short infusion reaching peak concentrations after 2 hours. In a prospective cross-over study we compared the pharmacokinetics of CsA and its metabolites after oral (2.0 mg/kg body weight) versus intravenous (0.7 mg/kg body weight; 2-hour infusion) CsA administration (single test dose) in 7 pre-HTx patients. The pharmacokinetic parameters of CsA and its metabolites were analyzed using high-pressure liquid chromatography. The pharmacokinetic parameter area under the concentration time curve (AUC(0-infinity)) of CsA after intravenous administration was significantly lower (2903 ng*h*mL(-1)) than that after oral administration (4344 ng*h*mL(-1); P=.01). Peak concentrations, time to peak concentration, and terminal elimination half life were not significantly different. Short-time infusion of CsA resulted in a significant decrease in the AUC of the metabolites AM1 (3-fold), AM9 (10-fold), and AM1c (3-fold). A 2-hour infusion of CsA is just as effective as oral administration and the reduced amount of metabolites is advantageous for the patient.

Ecological half-lives of 90Sr and 137Cs in terrestrial and aquatic ecosystems.

This paper describes the long-term behaviour of (90)Sr and (137)Cs in foods, feeds and a variety of environmental media. The long-term behaviour is quantified by means of the ecological half-life which integrates all processes that cause a decrease of activity in a given medium such as leaching, fixation and erosion. A large number of long-term time series of concentrations of radiocaesium and radiostrontium in these media have been identified and re-evaluated using a standardised statistical procedure to establish reference data sets of ecological half-lives. By example of undisturbed soils and marine water bodies it is shown that the ecological half-life concept is questionable if the distribution of the radionuclide of interest within the medium studied is non-uniform and if mixing and transport processes within this medium, therefore, are of considerable importance during the time period of observation.

[New concepts in ultrasound education in gastroenterology by simulator training]. / Neue Konzepte in der gastroenterologischen Sonographieausbildung durch Schulung am Ultraschallsimulator.

Ultrasound is one of the most important imaging methods in medicine. However, ultrasound education is complicated by varying quantities and qualities of specific pathologies resulting from distinct patient collectives. Furthermore, under current clinical conditions ultrasound educators as well as trainees frequently lack the time necessary for a sufficient ultrasound education. Finally, current ultrasound education materials including "gold standard" images are not ideally suited for teaching scanning three-dimensional pathologies. In a direct cross over study we recently proved, that the ultrasound simulator we developed simulated the real patient examination reliably and reproducibly. By using this simulator as well in the classical beginner and advanced level courses as in focused courses of abdominal emergencies for instance, ultrasound trainees are able to practice scanning of well defined pathologies under realistic conditions, which has not been possible before. Furthermore, the ultrasound simulator is well suited for a structured ultrasound training in single hospitals as well as in continuous medical education. Finally, objective, standardized ultrasound quality control has become possible with the simulator.

Modelling the vertical distribution of radionuclides in soil. Part 1: the convection-dispersion equation revisited.

The convective-dispersive transport and linear sorption model is discussed for the vertical migration of radionuclides in soil. An alternative procedure of solving the corresponding system of partial differential equations is presented as well as the special solution for the pulse-like fallout initial condition. Idealizations and simplifications of the model and properties of the solution are discussed. The model is fitted to a set of 528 measured radionuclide soil profiles and the resulting model parameters, apparent convection velocity v and apparent dispersion constant D, are evaluated statistically. Typical orders of magnitude of the velocities and the diffusion constants of Chernobyl-134Cs are 0.3 cm/year and 0.3 cm2/year, respectively. The mobilities of the radionuclides are ranked as 137Cs (global fallout) < 134Cs < 106Ru, 125Sb. Significant regional differences (related to different soils and geological properties below ground) of v and D exist. These analyses also indicate that v and D are not mere fitting parameters, but can be given a real physical interpretation. While in most cases, the convection-dispersion equation (CDE) model produces good descriptions for near-surface soil layers, potentially important limitations are its failure to describe "young" profiles shortly after fallout.

Simulation of abdomen sonography. Evaluation of a new ultrasound simulator.

AIM: We developed and evaluated a simulator for the sonography of the abdomen in order to improve the teaching quality in sonography training. METHOD: Eleven medicine residents who had received 4 to 12 months full time sonography training performed ultrasound examinations of the right upper quadrant in 5 consecutive patients and in 5 simulator cases. The correctness of their findings and the time required for the examinations were measured. The subjective confidence in their findings and the handling of the ultrasound machines were rated on a visual analogue scale. RESULTS: During patient ultrasound examination 75 % (SEM 9%) of all pathologic findings were recognized by the residents, whereas 71 % (SEM 8%) of the pathologies of the simulator cases were found. This minimal difference was not significant in the paired, two sided t-test (p = 0.15). Severe pathologies did not escape detection. The time required for patient examination(10.57 min, SEM 3.25 min) was not significantly different (p = 0.53) to the time required for the simulator cases (9.59 min, SEM 2.98 min). The subjective confidence in the sonographic findings did not differ significantly (p = 0.39) between the real patient situation (68%, SEM 6%) and the simulation (64%, SEM 12 %). Only the handling of the ultrasound machines was judged to be significantly better (p=0.008) than the simulator (74%,SEM 7% vs. 61 %, SEM 12%). CONCLUSION: In this first direct crossover comparison between real patient sonography and simulator based scanning we proved that the simulator we developed simulates the real patient examination reliably and reproducibly.

The potential of lichens as long-term biomonitors of natural and artificial radionuclides.

Lichens were used as biomonitors of Chernobyl fallout 137Cs, of cosmogenic 7Be and of radioactive members of the natural uranium and thorium decay chains. Samples were taken from two locations in France, including lichens sampled at different distances of a coal fired power plant and close to a uranium ore processing waste disposal site. All samples were analyzed gamma-spectrometrically after equilibrium concentrations of short-lived isotopes had been attained. Activity concentrations of the members of the uranium and thorium decay chains in Parmelia sulcata sampled 1994 decrease with distance from the plant, whereas in lichens taken at the waste disposal site a decrease with time was observed. Comparison of 7Be activity concentrations measured in lichens with atmospheric deposition rates confirms that P. sulcata can be used as a quantitative biomonitor of radioactive trace substances. Retention half-lives calculated with a simple one-compartment model are 2.6 +/- 1.2 years for cesium, which was detected in all samples even more than a decade after the Chernobyl accident, and of 0.7 (+/- 0.1) to 3.3 (+/- 0.7) years for lead. Consequences of our results for model identifiability and parameter estimation of a two-compartment model are discussed.

Comparative study analyzing effects of sirolimus-cyclosporin and sirolimus-tacrolimus combinations on bile flow in the rat.

The new immunosuppressive agent sirolimus is combined in transplant patients with the cholestatic substances cyclosporin and tacrolimus. Nothing is known about possible cholestatic effects of these combinations. Therefore, we compared their effects on bile flow and on important bile parameters in an acute bile fistula model in rats. Cyclosporin reduced bile flow, biliary excretion of bile salts, cholesterol, and GSH to 20-40% of basal values. Sirolimus decreased bile flow to 50% and excretion of GSH to 30% of the initial conditions but had no effect on cholesterol and bile salt excretion. In contrast, tacrolimus increased bile flow to 120% and GSH excretion to 220% of the basal levels. Sirolimus/cyclosporin decreased bile flow and bile parameters to the same extent as cyclosporin alone. Sirolimus/tacrolimus reversed sirolimus-induced reduction of bile flow and GSH excretion and resulted in a normal bile salt and cholesterol excretion, thus it may be the better alternative in cholestatic patients.