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International audience; The Central English Channel troughs correspond to elongated incisions up to 250 m-deep, at several locations at the bottom of this sea corridor. Depending on their location, they are usually interpreted as part of the submerged quaternary paleovalley network or as resulting from megaflood events. Shedding light on these features, their age, and the processes underlying their development is key for understanding their significance in terms of event geology. The interpretation of a dense grid of high-resolution marine seismic data acquired in the Bay of Seine area reveals that the extensive Quaternary paleovalley and trough network commonly as associated to the "Channel River" system is actually subdivided into at least two superimposed and unrelated incised networks. The overlying network corresponds to fluvial incisions developing during low sea-level conditions of Pleistocene time and connects to the present day fluvial network. The underlying network corresponds to the troughs and appears as a complex, deeper, relatively discontinuous and isolated network. This older network shows unexpected local incision depth up to c.350-400 m-deep and complex sedimentary infill involving several sedimentary processes and environments from fluvial to tidal and shallow-marine. We discuss these observations and their implications for understanding the origin, age and development of the troughs all over the English Channel, from the Dangeard Troughs in the Dover Strait to the Hurd Deep at the western end. We also raise questions about the significance of these large incised features in terms of source-to-sink system of northwestern Europe.

Measurements from the Large Hadron Collider (LHC) and the Relativistic Heavy Ion Collider (RHIC) can be used to study the properties of quark-gluon plasma. Systematic constraints on these properties must combine measurements from different collision systems and methodically account for experimental and theoretical uncertainties. Such studies require a vast number of costly numerical simulations. While computationally inexpensive surrogate models ("emulators") can be used to efficiently approximate the predictions of heavy ion simulations across a broad range of model parameters, training a reliable emulator remains a computationally expensive task. We use transfer learning to map the parameter dependencies of one model emulator onto another, leveraging similarities between different simulations of heavy ion collisions. By limiting the need for large numbers of simulations to only one of the emulators, this technique reduces the numerical cost of comprehensive uncertainty quantification when studying multiple collision systems and exploring different models., 15 pages, 6 figures, journal article

Retinitis pigmentosa (RP), an inherited blinding disease, is caused by a variety of different mutations that affect retinal photoreceptor function and survival. So far there is neither effective treatment nor cure. We have previously shown that poly(ADP-ribose)polymerase (PARP) acts as a common and critical denominator of cell death in photoreceptors, qualifying it as a potential target for future therapeutic intervention. A significant fraction of RP-causing mutations affect the genes for the rod photoreceptor phosphodiesterase 6A (PDE6A) subunit, but it is not known whether they all engage the same death pathway. Analysing three homozygous point mutations (Pde6a R562W, D670G, and V685M) and one compound heterozygous Pde6a (V685M/R562W) mutation in mouse models that match human RP patients, we demonstrate excessive activation of PARP, which correlated in time with the progression of photoreceptor degeneration. The causal involvement of PARP activity in the neurodegenerative process was confirmed in organotypic retinal explant cultures treated with the PARP-selective inhibitor PJ34, using different treatment time-points and durations. Remarkably, the neuroprotective efficacy of PARP inhibition correlated inversely with the strength of the genetically induced insult, with the D670G mutant showing the best treatment effects. Our results highlight PARP as a target for neuroprotective interventions in RP caused by PDE6A mutations and are a first attempt towards personalized, genotype-matched therapy development for RP. In addition, for each of the different mutant situations, our work identifies windows of opportunity for an optimal treatment regimen for further in vivo experimentation and possibly clinical studies.

In France, the present regulations on occupational exposure to asbestos fibers take into account fibers (FRp: fibers measured for industrial hygiene) with the following dimensions: L > 5 μm, D 3 where L is the length and D the diameter of the fiber. The limit value is set at 0.1 f/cm3 for 1 hr. By definition short asbestos fibers (SAFs) are the fibers with 0.5 μm < L< 5 μm, D < 3 μm, and L/D ≥ 3; thin asbestos fibers (TAFs) are the fibers with L ≥ 5 μm, D < 0.2 μm, and L/D ≥ 3. The aim assigned to the French Agency for Environmental and Occupational Health Safety (AFSSET) Occupational Exposure Limit (OEL) Committee, was essentially to evaluate the following elements: the relevance of the present French OEL, knowing that this limit excludes the counting of SAFs and TAFs; the consistency of the OEL in light of the different varieties of asbestos by studying possible differential toxicity according to the type of asbestos (chrysotile vs. amphiboles); and the assessment of different measurin...

Combustion modeling of energetic materials has undergone a tremendous amount of development in recent years. Gas-phase combustion properties predictions are possible and have been shown to agree with experimental results. For solid energetic materials, the gasification reaction products must be determined if gas-phase models are to be applied. The majority of actual models still involve a guessing step for gasification products due to the lack of knowledge in the condensed phase. Quantum dynamical calculations are presently the only way to predict initial condensed-phase reactions but require tremendous computing power, thus limiting their application. In this work, an empirical method that uses spectroscopic measurements of energetic molecules as the source for the complete modal molecular picture is presented. The method enables a qualitative prediction of the first combustion reaction in the condensed phase. The application of the methods with nitrocellulose and nitroguanidine shows that it pr...

Recent epidemiological studies of the association between lung cancer and exposure to radon and its decay products are reviewed. Particular emphasis is given to pooled case-control studies of residential exposures, and to cohorts of underground miners exposed to relatively low levels of radon. The residential and miner epidemiological studies provide consistent estimates of the risk of lung cancer, with significant associations observed at average annual concentrations of approximately 200 Bq/m³ and cumulative occupational levels of approximately 50 working level months (WLM), respectively. Based on recent results from combined analyses of epidemiological studies of miners, a lifetime excess absolute risk of 5 × 10⁻⁴ per WLM [14 × 10⁻⁵ per (mJh/m³)] should now be used as the nominal probability coefficient for radon- and radon-progeny-induced lung cancer, replacing the previous Publication 65 (ICRP, 1993) value of 2.8 × 10⁻⁴ per WLM [8 × 10⁻⁵ per (mJh/m³)]. Current knowledge of radon-associated risks for organs other than the lungs does not justify the selection of a detriment coefficient different from the fatality coefficient for radon-induced lung cancer. Publication 65 (ICRP, 2003) recommended that doses from radon and its progeny should be calculated using a dose conversion convention based on epidemiological data. It is now concluded that radon and its progeny should be treated in the same way as other radionuclides within the ICRP system of protection; that is, doses from radon and its progeny should be calculated using ICRP biokinetic and dosimetric models. ICRP will provide dose coefficients per unit exposure to radon and its progeny for different reference conditions of domestic and occupational exposure, with specified equilibrium factors and aerosol characteristics.

Sensorimotor adaptation is thought to involve a remapping of the kinematic and kinetic parameters associated with movements performed within a changing environment. Patients with Parkinson's disease (PD) are known to be affected on this type of learning process, although the specific role of dopamine depletion in these deficits has not yet been elucidated. The present study was an attempt to clarify whether dopamine depletion in PD may directly affect the capacity to internally reorganize the visuomotor remapping of a distorted environment. Fourteen PD patients were tested twice, while they were treated and while they were withdrawn from their regular levodopa treatment. Fourteen control subjects were also enrolled and tested twice. Two parallel forms of the Computed Mirror Pointing Task (CMPT), requiring making a reaching movement in a visually transformed environment (mirror inversion), were administered to each participant. Each of them had to perform 40 trials at each of the 2 testing sessions. At each trial, sensorimotor adaptation was evaluated by the initial direction angle (IDA), which reflects the direction of movement before any visually guided readjustment. Results revealed no IDA difference at baseline, between control subject and PD patients, whether they were treated or not. In all group, IDA values at that time were large, reflecting a tendency to make movements according to the real life visuomotor mapping (based on the natural direct vision). However, striking differences appeared during sensorimotor learning, in that IDA reduction along trials was poorer in patient not treated with levodopa than both control subjects and the same PD patient treated with levodopa. No difference was observed between the treated PD patients and control subjects. Given that IDA is thought to reflect the internal representation of the visuomotor mapping, it is concluded that dopamine depletion in PD would affects sensorimotor adaptation, in that it facilitates old and poorly adapted movements (real life mapping), instead of new and more adapted ones (mirror transformed mapping).

Hazardous chemical, radiological, and nuclear materials threaten public health in scenarios of accidental or intentional release which can lead to external ontamination of people. Without intervention, the contamination could cause severe adverse health effects, through systemic absorption by the contaminated casualties as well as spread of contamination to other people, medical equipment, and facilities. Timely decontamination can prevent or interrupt absorption into the body and minimize opportunities for spread of the contamination, thereby mitigating the health impact of the incident. Although the specific physicochemical characteristics of the hazardous material(s) will determine the nature of an incident and its risks, some decontamination and medical challenges and recommended response strategies are common among chemical and radioactive material incidents. Furthermore, the identity of the hazardous material released may not be known early in an incident. Therefore, it may be beneficial to compare the evidence and harmonize approaches between chemical and radioactive contamination incidents. Experts from the Global Health Security Initiative’s Chemical and Radiological/Nuclear Working Groups present here a succinct summary of guiding principles for planning and response based on current best practices, as well as research needs, to address the challenges of managing contaminated casualties in a chemical or radiological/nuclear incident.

Aerosols produced during impacts of depleted uranium (DU) penetrators against the glacis (sloping armour) and the turret of a tank were sampled. The concentration and size distribution were determined. Activity median aerodynamic diameters were 1 microm (geometric standard deviation, sigma(g) = 3.7) and 2 microm (sigma(g) = 2.5), respectively, for glacis and turret. The mean air concentration was 120 Bq m(-3), i.e. 8.5 mg m(-3) of DU. Filters analysed by scanning electron microscopy (SEM) and X ray diffraction showed two types of particles (fine particles and large molten particles) composed mainly of a mixture of uranium and aluminium. The uranium oxides were mostly U3O8, UO2.25 and probably UO3.01 and a mixed compound of U and Al. The kinetics of dissolution in three media (HCO3-, HCl and Gamble's solution) were determined using in-vitro tests. The slow dissolution rates were respectively slow, and intermediate between slow and moderate, and the rapid dissolution fractions were mostly intermediate between moderate and fast. According to the in-vitro results for Gamble's solution, and based on a hypothetical single acute inhalation of 90 Bq, effective doses integrated up to 1 y after incorporation were 0.54 and 0.56 mSv, respectively, for aerosols from glacis and turret. In comparison, the ICRP limits are 20 mSv y(-1) for workers and 1 mSv y(-1) for members of the public. A kidney concentration of approximately 0.1 microg U g(-1) was predicted and should not, in this case, lead to kidney damage.

Thefocus of the work of Committee 2 of the International Commission on Radiological Protection (ICRP) is the computation of dose coefficients compliant with Publication 103. A set of reference computational phantoms is being developed, based on medical imaging data, and used for radiation transport calculations. Biokinetic models used to describe the behaviour of radionuclides in body tissues are being updated, also leading to changes in organ doses and effective dose coefficients. Dose coefficients for external radiation exposure of adults calculated using the new reference phantoms were issued as Publication 116, jointly with the International Commission on Radiation Units and Measurements. Forthcoming reports will provide internal dose coefficients for radionuclide inhalation and ingestion by workers, and associated bioassay data. Work is in progress to revise internal dose coefficients for members of the public, and, for the first time, to provide reference values for external exposures of the public. Committee 2 is also working with Committee 3 on dose coefficients for radiopharmaceuticals, and leading a cross-Committee initiative to give advice on the use of effective dose. © 2016, © The International Society for Prosthetics and Orthotics.

The duration of cell death may allow deducing the underlying degenerative mechanism. To find out how long a photoreceptor takes to die, we used the rd1 mouse model for retinal neurodegeneration, which is characterized by phosphodiesterase-6 (PDE6) dysfunction and photoreceptor death triggered by high cGMP levels. Based on cellular data on the progression of cGMP accumulation, cell death, and survival, we created a mathematical model to simulate the temporal development of the degeneration and the clearance of dead cells. Both cellular data and modelling suggested that at the level of the individual cell, the degenerative process was rather slow, taking around 80 h to complete. Organotypic retinal explant cultures derived from wild-type animals and exposed to the selective PDE6 inhibitor zaprinast, confirmed the surprisingly long duration of an individual photoreceptor cell's death. We briefly discuss the possibility to link different cell death stages and their temporal progression to specific enzymatic activities known to be causally connected to cell death. This in turn opens up new perspectives for the treatment of inherited retinal degeneration, both in terms of therapeutic targets and temporal windows-of-opportunity.

Different strategies for the treatment of inherited photoreceptor degeneration are currently being investigated, with each of these approaches facing specific challenges. Gene therapy, for instance, may be feasible only for genetically well-defined pathologies. However, inherited retinal disorders are genetically highly heterogeneous and early onset disorders may restrict the therapeutic window. The majority of currently developed molecular approaches aim at the reconstitution of physiologically important functions in RPE and photoreceptor. Neuroprotection attempts to prolong cell survival and proper function via sustained delivery systems that fulfil a long-term dynamic reservoir function for therapeutic neuroprotective compounds. Cell-based approaches include replacement strategies such as cell transplantation, the implantation of prosthetic devices or optogenetics. They aim at replacing lost neurosensory functions of the retina. This short review aims at providing an insight into current therapeutic strategies and future treatment options for retinal disorders. Pharmacological and nutritional support strategies are only briefly discussed as we focus here on molecular and prosthetic therapeutic approaches.

3,4,3 LI 1,2 HOPO 1 or LIHOPO (1,5,10,14-tetra (1-hydroxy-2-pyridone-6-oyl)-1,5,10,14-tetraazatetradecane.) is a decorporation agent used against actinides. It was synthesised labelled with carbon 14 with a view to metabolism studies. [6,9-14C]-LIHOPO 2 was obtained in two radioactive steps through a very convenient synthesis in 50% radioactive yield from commercially available [1,4-14C]-spermine, hydrochloride and 1-benzyloxy-6-oxo-1,6-dihydropyridine-2-carbonyl chloride 7. The synthesis of 7 is also described. Copyright © 2001 John Wiley & Sons, Ltd.

RESUMELa phytoprotection des cultures maraicheres est tres importante au Quebec et au Canada. Il est donc important d'assurer une bonne surveillance des cultures mais surtout de se doter d'outils nous permettant d'elaborer des strategies d'intervention les plus appropriees. La prevision des dommages causes par les ennemis des cultures est effectuee a partir de modeles specifiques aux differents ravageurs. Les modeles utilisent comme principaux intrants les donnees meteorologiques mesurees par les reseaux meteorologiques de surface, comme la temperature de l'air, la precipitation et l'humidite. Or, les reseaux actuels de mesures ne repondent pas adequatement aux besoins et les conseillers agricoles doivent utiliser d'autres moyens pour acquerir les donnees de base et actualiser les previsions. Les intervenants ont donc recours a la modelisation spatio-temporelle des donnees agrometeorologiques et environnementales pour la phytoprotection des cultures, ce qui necessite l'estimation des parametres agrometeor...

The present paper aims to present a new approach allowing evaluation of the spatial representativity of the air temperature measured at meteorological stations. Taking into account NOAA-AVHRR derived surface temperatures and environmental data of the station surroundings, an evaluation of the meteorological network is made. A series of surface temperature maps are prepared from NOAA-AVHRR images. The spatial variability of the thermal field around each station is analysed together with the environmental conditions and as a function of the season. The zone of spatial representativity for each meteorological station is then defined. The paper presents preliminary results obtained for some meteorological stations in Andalusia in southern Spain. Le present article vise â presenter une nouvelle approche permettant d'evaluer la representativite spatiale de la temperature mesuree aux stations meteorologiques. Ainsi en considerant les donnees satellitaires NOAA-AVHRR et l'information relative au cadre environneme...

This paper presents the results of a partnership between Alstom and Hydro-Quebec for the development of a new factory robotic polishing process. The goal is to improve turbine efficiency by reducing surface roughness to a level that is unattainable with conventional methods. Three entire axial-flow turbines for Hydro-Quebec's Sarcelle power station were polished with this new technique at the Alstom manufacturing plant in Sorel-Tracy as a pilot project between July 2010 and March 2011. The surface finish was lowered from Ra = 15 μm to Ra = 0.1 μm, and the waviness left by numerical control machining was grinded away at an overall rate of 5 h/m2. The reduction of surface roughness from the standard IEC recommendation of Ra=3 μm to Ra=0.1 μm resulted in a 0.5% increase in turbine efficiency. This safe, new method proves its great potential for enhanced surface finish quality, productivity and worker safety.

The development of new techniques in nuclear industry will involve increasing actinide manipulations. As a consequence, it is necessary to define a specific treatment in case of internal contamination. A review has been carried out of 50 references relating to the biological behaviour of neptunium and the decorporation efficiency of usual treatments. As a conclusion, there is no efficient thera­ peutics to remove neptunium after internal incorporation. New studies should now be developed, with particular attention focused on the behaviour of neptu­ nium at the subcellular and molecular levels.

Recent epidemiological studies of the association between lung cancer and exposure to radon and its decay products are reviewed. Particular emphasis is given to pooled case-control studies of residential exposures, and to cohorts of underground miners exposed to relatively low levels of radon. The residential and miner epidemiological studies provide consistent estimates of the risk of lung cancer, with significant associations observed at average annual concentrations of approximately 200 Bq/m³ and cumulative occupational levels of approximately 50 working level months (WLM), respectively. Based on recent results from combined analyses of epidemiological studies of miners, a lifetime excess absolute risk of 5 × 10⁻⁴ per WLM [14 × 10⁻⁵ per (mJh/m³)] should now be used as the nominal probability coefficient for radon- and radon-progeny-induced lung cancer, replacing the previous Publication 65 (ICRP, 1993) value of 2.8 × 10⁻⁴ per WLM [8 × 10⁻⁵ per (mJh/m³)]. Current knowledge of radon-associated risks for organs other than the lungs does not justify the selection of a detriment coefficient different from the fatality coefficient for radon-induced lung cancer. Publication 65 (ICRP, 2003) recommended that doses from radon and its progeny should be calculated using a dose conversion convention based on epidemiological data. It is now concluded that radon and its progeny should be treated in the same way as other radionuclides within the ICRP system of protection; that is, doses from radon and its progeny should be calculated using ICRP biokinetic and dosimetric models. ICRP will provide dose coefficients per unit exposure to radon and its progeny for different reference conditions of domestic and occupational exposure, with specified equilibrium factors and aerosol characteristics.

This paper describes the approach taken by Alstom and Hydro-Quebec (HQ) in the development of robotic polishing to improve turbine efficiency by reducing surface roughness. Modern, large hydraulic turbines are profiled by a 5-axis milling machine and are polished manually. By robotizing the polishing, it becomes possible to obtain a better surface finish at a reasonable cost, and to reduce hydrodynamic friction loss. HQ's portable robot Scompi was used to perform the polishing. Recent developments made by the supplier of the abrasives have resulted in their increased durability and improved productivity. A technique was developed to select the polishing process parameters best suited to a given surface waviness and roughness. A polishing test was carried out on a full-scale Francis turbine blade. The surface finish was lowered from Ra=15µm to Ra=0.1µm and the waviness (scallop 0.2mm tall and 30mm wide) was grinded away at a rate of 5 hour/m2.

International audience; BACKGROUND: A pilot study was carried out in the AREVA NC Pierrelatte nuclear facility in order to investigate a possible carcinogenic effect of internal radiation exposure among nuclear workers in France. The objective of this study was to develop a method for retrospective reconstruction of the occupational exposure to internal radiation from uranium and associated chemical exposures. METHODS: A plant- and period-specific job exposure matrix (JEM) was designed. Job groups and exposure agents groups including uranium compounds and other chemical agents known as being carcinogenic, mutagenic or toxic were defined by an expert committee. Exposure was evaluated by active and retired workers included in the evaluator committee. A quantitative assignment of quantity and frequency of handling (both coded from 0 to 3) was performed for each agent groups using a method derived from the Delphi technique. RESULTS: In all, 23 experts and 353 evaluators participated to the JEM elaboration. A final JEM involved 232 "job-periods" presenting throughout the plant period 1960-2006 and 22 exposure agents groups in use at the plant. Six of them involved uranium compounds classified by their blood-transferability and toxicity characteristics. A first validation of the JEM by experts in radiological protection and industrial hygiene showed an acceptable internal consistency. CONCLUSION: In the context of missing past exposure measurement data, the plant- and period-specific job exposure matrices may be considered as a valid alternative for exposure estimation. This method may be applied to other nuclear plants and offers allowance to investigate a possible carcinogenic effect of internal radiation exposure among nuclear workers.; Objectifs : Afin d’étudier les effets cancérigènes de la contamination interne chez lestravailleurs du secteur nucléaire en France, une étude pilote est mise en place au sein del’établissement AREVA NC Pierrelatte. Son objectif est de développer une méthodepermettant d’évaluer l’exposition interne à l’uranium ainsi que les expositions chimiquesassociées.Méthodes : Une matrice emplois-expositions (MEE) période et site spécifique a été élaborée.La liste des emplois et la liste des expositions - produits uranifères et ceux classéscancérogènes, mutagènes ou toxiques pour la reproduction (CMR) - ont été définies par uncomité d’experts pluridisciplinaire. Un comité d’évaluateurs composé des travailleurs del’établissement en activité et des travailleurs retraités a évalué les expositions. Pour chaqueproduit retenu, deux paramètres d’exposition ont été évalués sur une échelle à 4 niveaux: lafréquence d’utilisation du produit et la quantité du produit avec laquelle le travailleur a été encontact. Le processus d’évaluation a été standardisé. Les notes finales de la matrice ont étéobtenues à partir des réponses du comité d’évaluateurs, en utilisant une technique dérivée dela méthode Delphi, puis validées par le comité d’experts.Résultats : La construction de la MEE spécifique de l’établissement AREVA NC Pierrelattes’appuie sur le travail de 23 experts et 353 évaluateurs. La MEE finale met en correspondance232 postes-périodes existant entre 1960 et 2006 et 22 catégories de produits utilisés dansl’établissement. Les produits uranifères sont classés en six catégories selon leur puretéchimique et leur transférabilité dans les tissus biologiques. L’examen de la MEE par le comitéd’experts montre une cohérence interne satisfaisante et constitue sa première validation.Conclusion : Dans un contexte d’absence des données individuelles d’exposition, la MEEpériode et site spécifique constitue une alternative valide d’évaluation rétrospective del’exposition. Cette méthode peut être transposée à d’autres établissements de l’industrie nucléaire et permet d’évaluer le rôle de l’exposition interne à l’uranium et des expositionsassociées chez les travailleurs.

The ICRP Task Group on Internal Dosimetry is developing new Occupational Intakes of Radionuclides (OIR) documents. Application of the Human Respiratory Tract Model (HRTM) requires a review of the lung-to-blood absorption characteristics of inhaled compounds of importance in radiological protection. Where appropriate, material-specific absorption parameter values will be given, and for other compounds, assignments to default Types will be made on current information. Publication of the OIR provides an opportunity for updating the HRTM in the light of experience and new information. The main possibilities under consideration relate to the two main clearance pathways. Recent studies provide important new data on rates of particle transport from the nasal passages, bronchial tree (slow phase) and alveolar region. The review of absorption rates provides a database of parameter values from which consideration can be given to deriving typical values for default Types F, M and S materials, and element-specific rapid dissolution rates. © The Author 2007. Published by Oxford University Press. All rights reserved.

All the existing and planned broadband access delivery systems have at least one point where some concentration takes place. This broadband node concentrates a large number of services with different behaviour such as take rates, usages and bandwidths. Then, there is a need for a dimensioning tool to size these nodes where concentration takes place. A blocking model is presented along with a relevant service set definition. This work is then used to develop a dimensioning tool for broadband nodes in the access system. The tool can be used to determine the bandwidth needed to serve a given population or, with a given bandwidth, to evaluate the population served.

The regionalization of agrometeorological parameters such as the air temperature, for a given region is limited by the meteorological network system. The Quebec meteorological network does not adequately satisfy the needs of the agro-food industry of the province. The number of stations is insufficient and some stations need to be resited to meet the needs of farmers. Interpolation of data collected at each station has always been used. Results thus obtained are not representative of real meteorological conditions. The authors have to recommend an other approach to increase the spatial resolution of the actual agrometeorological network. The integration of physiographical, agricultural and satellite data has allowed the identification of homogeneous agrometeorological zones. Each zone can have a better optimization and spatialization of agrometeorological data measured by the network. The regionalization of the air temperature at the stations in each zone is then possible.

In this paper, an experimental investigation is implemented on the abrasive waterjet polishing technique to evaluate its capability in polishing of surfaces and edges of hydraulic turbine blades. For this, the properties of this method are studied and the main parameters affecting its performance are determined. Then, an experimental test-rig is designed, manufactured and tested to be used in this study. This test-rig can be used to polish linear and planar areas on the surface of the desired workpieces. Considering the number of parameters and their levels, the Taguchi method is used to design the preliminary experiments. All experiments are then implemented according to the Taguchi L18 orthogonal array. The signal-to-noise ratios obtained from the results of these experiments are used to determine the importance of the controlled polishing parameters on the final quality of the polished surface. The evaluations on these ratios reveal that the nozzle angle and the nozzle diameter have the most important impact on the results. The outcomes of these experiments can be used as a basis to design a more precise set of experiments in which the optimal values of each parameter can be estimated.

Data on the gastrointestinal absorption of 12 elements have been reviewed. In each case, absorption is expressed as the fraction of the ingested element absorbed to blood, referred to as the f1 value, applying to intakes of unspecified chemical form by average population groups. The level of confidence in individual absorption values has been estimated in terms of lower and upper bounds, A and B, such that there is judged to be roughly a 90% probability that the true central value is no less than A and no greater than B. Ranges are proposed for intakes by adults, 10-year-old children and 3-month-old infants. Uncertainty in f1 values (B/A) ranged from 10% to factors of 100-400. The lowest uncertainties were for the well absorbed elements, H, I and Cs, for which there are good data, and the greatest uncertainties were for less well absorbed elements for which few data are available, particularly Zr and Sb. Ranges were generally wider for children and infants than for adults because of the need to allow for the likelihood of increased absorption with only limited data in support of the proposed values. The largest ranges were for 3-month-old infants, reflective lack of knowledge on the time-course and magnitude of possible increased absorption in the first few months of life. For each age group, ICRP values of absorption tend towards the upper bound of the ranges, indicating a degree of conservatism in th calculation of ingestion dose coefficients. Examination of the effect of the proposed confidence intervals for f1 values on uncertainties in dose coefficients for ingested radionuclides showed that there was no direct relationship. For some radionuclides, uncertainties in effective dose were small despite large uncertainties in f1 values while for others the uncertainties in effective doses approached the corresponding values for uncertainty in f1 values. These differences reflect the relative contributions to effective dose from cumulative activity in the contents of the alimentary tract, which in many cases is insensitive to uncertainties in f1, and cumulative activity of the absorbed radionuclide in systemic tissues, which is proportional to f1. In general, uncertainties in effective close for children and infants exceeded those in adults as a result of greater uncertainties in f1 values for the younger age groups. However, this effect was reduced in some cases by shorter retention times of absorbed nuclides in body tissues and organs.

The aim of the paper is to develop a new approach to treat uranium-contaminated wounds. The efficacy of a local uranium chelator, carballylic amido bis phosphonic acid (CAPBP) was assessed using two different uranium compounds. Rats were contaminated by intramuscular injections of uranyl nitrate or an industrial U04 compound to simulate wound contamination. CAPBP was injected intramuscularly (im) or intraperitoneally (ip) at a dosage of 30,umol kg-. In one experiment, the local administration of CAPBP was combined with a systemic administration of ethane-1-hydroxy-1,1-biphosphonate (EHBP). The local CAPBP treatment resulted in increased retention of uranium at the wound site: about 30% for uranyl nitrate or U04 after the first day and about 15% of U04 after the third day. Consequently, it reduced uranium translocation into the blood and deposition in the kidneys and bone. The combined treatment reduced the uranium deposits in the kidneys, bone and carcass to about one-half of those observed in controls 3 days after U04 contamination. The local CAPBP treatment increased the interval of time between contamination and uranium deposit in the target organs. Thus, it can increase the efficacy of nonspecific local treatments or specific systemic treatments. It could be given rapidly through spray or gel after an accident.

Purpose : The gastrointestinal absorption and systemic distribution of uranium and neptunium were determined after external gamma irradiation. Materials and methods : Rats were exposed to a single whole-body dose of gamma radiation (6 Gy; 0.75 Gy.min -1) . Three days after irradiation they were orally and/or intravenously contaminated with 100 μ g.kg -1 uranium or 3 kBq.kg -1 neptunium. The gastrointestinal absorption and organ distribution of both radionuclides were measured 6 days after irradiation. Results : External irradiation increased the intestinal transit time of uranium and neptunium but had no effect on their gastrointestinal absorption. The average fractional absorption was determined to be 0.93 and 0.98% (uranium) and 4.7 and 4.8% (neptunium) for the irradiated and non-irradiated rats respectively. The excretion of uranium and neptunium was not affected by the irradiation. Conclusion : A 6 Gy whole-body irradiation (gamma; 0.75 Gy.min -1) did not affect the absorption of uranium and neptunium...

Objective: A number of menopausal women experience skin sensitive to various environmental threats. Method: Two panels of 15 menopausal women on or without HRT were compared. We studied the response of their stratum corneum to variations in environmental humidity, either in air or in response to an emollient. Environmental dew point and electrometric measurements on the skin were recorded to search for correlations. Results: Data show that the baseline stratum corneum hydration is influenced by the dew point. HRT improves the barrier function of the skin. The use of emollient further extends the improvement in the functional properties of skin in menopausal women. Conclusion: Both HRT and an emollient can counteract in part some of the deleterious effects of cold and dry weather.

The present investigation was aimed at establishing the distribution of neptunium in blood and liver cells as a function of the mass and chemical form of the radionuclide injected. Four groups of rats received intravenous injections of 237Np(V), 237Np(IV), 239Np(V) or 239Np(IV). Twenty-four hours after injection of the radionuclide, subcellular structures of the liver were separated by ultracentrifugation and serum and liver cytosol were subjected to gel permeation chromatography. The intracellular distribution of neptunium in liver depends on the mass of the radionuclide injected; the relative specific activity for 237Np compared to 239Np was 2 in nuclei and 0.5-0.9 in cytosol. By contrast, the initial chemical form of the radionuclide has no significant effect on its intracellular distribution. In cytosol, neptunium was bound mainly by two proteins of molecular weight 450 and 200 kDa, respectively. The former was identified as ferritin, but the latter remains unidentified. In this compartment, no effect of mass or chemical form was seen. In blood, the bulk of the radionuclide was bound to transferrin whatever the mass and initial chemical form injected.

Three series of ultrastructural studies are carried out with adult male Sprague Dawley rats injected with 239plutonium citrate. Two groups of rats are used in the first series of experiments. The animals of the first group are injected with 5 x 2.3 KBq while the animals of the second group received 5 x 9.25 KBq. The animals of the second series of experiment are injected with a single dose of 1 KBq while the animals of the third series received 5 x 200 Bq. Seven days after the first injections, animals kidneys of the first series of experiments have serious mitochondrial alterations in the proximal convoluted tubular and glomerular cells. Bone marrow cells have the same type of mitochondrial alterations as the above kidney cells. The affected mitochondria are swollen and have their cristae partially or completely destroyed. Very slight subcellular alterations are noted in the livers. The same type of alterations are observed in the kidney and bone marrow samples of the animals two days after injection of 1 KBq, but 23 days later no more ultrastructural alteration are noticed. No subcellular alterations are observed in the animals of the third series. These observations suggest that the chemical origin of these cellular lesions has to be taken into consideration even if the mass of injected radionuclide is low (2.04-81.6 mg/kg).

The present investigation was aimed at establishing the distribution of 237Np within the different structures of hepatocytes. Rats were contaminated experimentally by intravenous injection of 237Np (V) and the subcellular structures of the liver were separated by ultracentrifugation. Twenty-four hours after contamination, the nuclear and cytosolic fractions bound 54 and 32%, respectively, of the total radionuclide. Purification of the nuclei followed by dissociation of the protein components in medium of increasing ionic strength showed a specific binding of neptunium to the structural proteins of the nuclear matrix.

In the lobster, most of the radionuclides ingested with contaminated food are concentrated in the digestive gland. Americium-241 accumulation in the hepatopancreas of the lobster was studied during the digestive cycle. Fractionations of cytosols at different times after ingestion of radioactive preys were performed by gel permeation chromatography to determine the distribution of 241Am in the different macromolecular components. 241Am was associated with ferritin during the whole digestive cycle. This observation suggests a correlation between 241Am distribution pathways and iron metabolism. The distribution of 241Am present in the other cytosolic proteins followed two major steps of accumulation which may be correlated to the evolution of the two main cellular types playing an important role in the digestive cycle (B and R type cells).

In previous papers, we observed that there were great differences in the subcellular accumulation and elimination of 137Cs, 99Tc and 241Am in different marine animals. In this study, we analysed and compared the behaviour of these radionuclides at the cytosolic level. We found great similarities in the cytosolic distribution of a given radionuclide in the various organisms studied. The chemical characteristics of the radionuclides seem to play a major role in the biochemical affinity and metabolic behaviour in different aquatic organisms.

Recent studies on the bio-accumulation of transuranic elements in marine invertebrates have demonstrated an intracellular concentration of radionuclides in the digestive gland. The present investigation aims to establish the distribution of [241Am] within the different structures of the cell nucleus. Lobsters were experimentally contaminated through feeding and then killed. The nuclei of hepato-pancreatic cells were isolated, purified and dissociated. The different protein categories were separated in media of increasing ionic strength. The distribution of americium in this material yielded results showing a preferential fixation onto the structural proteins of the nuclear matrix. The radiological consequences of such an affinity are discussed in terms of the life-times of the ligands concerned.

This study evaluated influences of time of administration on the response to allergy skin prick tests. There was no significant difference between the mean +/- SEM wheal diameter of positive responses obtained in the morning, 2.98 +/- 0.19 nm, or in the evening, 3.14 +/- 0.18 mm (n = 175).

Low speed wind tunnel tests have been carried out to assess the combined drag reduction effects of longitudinally grooved or “ribleted” surfaces and upstream tandem turbulence manipulators or LEBUs (Large Eddy Break-Up devices). Skin friction and surface drag measurements are presented covering the regions upstream, over and downstream of the ribleted plate, both with and without LEBUs. Surface drag surveys using servo-controlled, floating element balances indicated non-linear drag reduction effects when the two devices are used together. On their own the asymmetrically shaped triangular riblets produced an average drag reduction of 5% over the ribleted section based on local direct balance measurements.