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1

Evaluation of induced radioactivity in 10 MeV-Electron irradiated spices, (2); [beta]-ray counting  

In order to check radioactivity of beta-emmitters produced by ([gamma], n) reactions which could occur at energies up to 10 MeV, black pepper, white pepper, red pepper, ginger and turmeric were irradiated with 10 MeV electron from a linear accelerator to a dose of 100 kGy. Beta-rays were counted using a 2[pi] gas flow counter and a liquid scintillation counter. Any induced radioactivity could not be detected in irradiated samples. When inorganic compounds containing the nuclides in the list were artificially added in the samples and were irradiated, the [beta]-activities were detected. From the amount of observed radioactivities of [beta]-emmitters produced in the compounds as photonuclear products, it is concluded that the induced radioactivity in natural samples by 10 MeV-electron irradiation were far smaller than natural radioactivity from [sup 40]K contained in the samples and, hence, its biological effects should be negligible. (author).

2

Effect of ethanol and the catalase inhibitor aminotriazole on lipid peroxidation in the rat myocardium  

The authors study the effect of chronic administration of ethanol and aminotriazole on the level of lipid peroxidation in the ray myocardium. The action of natural and artificial antioxidants on alcohol-induced lipid peroxidation also was studied. To determine the level of chemiluminescence, 1 ml of a sample of nuclear free homogenate or of the total fraction of particles was introduced for radioactivity measurement. After incubation the spontaneous weak luminescence was measured.

3

Continuous measurement of the lysis of /sup 125/I-labelled fibrin clots  

Methods for continuous measurement of the dissolution of experimentally induced /sup 125/I-labelled thrombi were described. They are suited for the use in artificial circulating systems and in animal experiments. The radioactivity can be measured continuously in a circulating system by fitting a flow through cell with a well scintillator. In order to measure thrombolytic processes in vivo, a specially adapted single hole collimator was developed. By this device changes in radioactivity over a defined occluded area of the vessel could be detected. The usefulness of the methods was demonstrated by means of a thrombolytic agent.

4

Henry Becquerel, Pierre and Marie Curie and radioactivity: background, circumstances and implication of the founder discoveries; Henri Becquerel, Pierre et Marie Curie et la radioactivite: contexte, circonstances et portee des decouvertes fondatrices  

After Roentgen`s X-rays discovery in 1895, Henry Becquerel discovers a proper radiation of uranium. Then, Pierre and Marie Curie discover polonium and radium. They establish that some atoms may produce spontaneously energy under radiations form which may lead to induce radioactivity. The essential interpretation was done by Rutherford with the distinction of alpha, beta and gamma radiations, and the atomic model of Rutherford-Bohr. The first transmutations under radiations effects lead to the neutrons discovery by Bothe and Becker, Irene Curie and Frederic Joliot, and to the interpretation by Chadwick, the artificial radioactivity of phosphorous by I. Curie and F. Joliot, and to the fission. (A.B.). 7 photos.

5

Determination of beta activity in water  

Many elements have one or more naturally radioactive isotopes, and several hundred other radionuclides have been produced artificially. Radioactive substances may be present in natural water as a result of geochemical processes or the release of radioactive waste and other nuclear debris to the environment. The Geological Survey has developed methods for measuring certain of these .radioactive substances in water. \\r\

6

The table of isotopes eary story  

The first complete Table of Isotopes, entitled {open_quotes}A table of induced radioactivities,{close_quotes} consisting of 13 pages including references, was published by John J. Livingood and me in the January, 1940 issue of Reviews of Modern Physics; this publication also included a table {open_quotes}Stable Isotopes of the Elements{close_quotes} but didn`t include the natural radioactivities. This was soon followed by a similar {open_quotes}Complete list of induced radioactivities{close_quotes} included in my extensive article {open_quotes}Artificial Radioactivity{close_quotes} published in the August 1940 issue of Chemical Reviews. Then during World War II, working at the wartime Metallurgical Laboratory of the University of Chicago (but with camouflaged identification with U.C. Berkeley) I published in the January 1944 issue of Rev. Mod.-Phys. a 32-page {open_quotes}Table of Isotopes{close_quotes} which included the stable isotopes and natural radioactivities. My {open_quotes}Table of Isotopes{close_quotes} in Rev. Mod. Phys. was updated in 1948 (83 pages), 1953 (182 pages), 1959 (319 pages) with Isadore Perlman, Jack M. Hollander and Donald Strominger as various co-authors.

7

A report on CERN's radiological impact  

According to the Federal Office for Public Health, every person living in Switzerland receives an average dose of 3.68 millisieverts per year coming from both natural radioactivity (e.g. cosmic rays, radon, terrestrial radioactivity, internal exposure) and artificial radioactivity (e.g. medical procedures). CERN's activities are estimated to account for around 0.27% of this annual dose. Source: Rapport annuel radioactivité de l

8

Influence of natural radioactive aerosols on artificial radioactivity detection in the Spanish surveillance networks  

The device used for continuous measurements of artificial {alpha} and {beta} activity in Spanish radiological surveillance networks is the LB BAI 9850 monitor from the Berthold Company. The temporal variation of radon decay product equilibrium introduces a varying background signal in the artificial radioactivity in these monitors. This unwanted background signal can be significantly reduced by analyzing natural radioactive aerosols and their influence on the monitor.

9

A survey of radioactive levels of agricultural products in Saitama prefecture  

Past atmospheric nuclear testing which have been conducted frequently, have caused environmental pollution due to the diffusion of radioactive substances into the atmosphere and from the radioactive fallout. The environmental pollution from nuclear testing into the atmosphere has resulted in the radioactive contamination in agricultural products and has continued for a long time. The radioactive contamination of agricultural products occurs through air, water and soil which were contaminated by radioactive fallout. In this paper, for the purpose of analyzing the extent of the radioactive contamination levels in the agricultural products of Saitama Prefecture, spinach, green soybeans, dried shiitake and welsh onion, were selected among products, as the amount of the harvest is abundant in all of Japan. Radioactivity concentration was investigated by gamma-ray spectrometry and radiochemical analysis. The radioactivity concentrations of artificial radioactive nuclides, cesium-137 ({sup 137}Cs) and strontium-90 ({sup 90}Sr), were detected in the range which is considered to be the result of radioactive fallout. Moreover, in order to examine the effect on radioactivity concentrations in agricultural products by culinary processing, the raw agricultural products were boiled, and their radioactivity concentrations were compared with the raw produce. The radioactivity concentrations in the boiled were lower than those in the raw produce. (author)

10

Radio-phobia, fantasies and realities; Radiophobie, fantasmes et realites  

After having criticized the attitude of the media after the discovery of a higher than normal radioactivity level on a beach of Camargue, which was in fact due to a natural phenomenon and had no health consequences, the author discusses the fear associated with radioactive radiations. He recalls the critical levels expressed in Sievert, the different levels associated either with natural or artificial radioactivity. He notices that radiation is generally feared whatever its radioactive level is. He outlines that the number of natural cancers is already relatively high. He finally proposes the use of the DARI as a unit (DARI stands for annual dose due to internal radiation)

11

Labeling of rabbit neutrophils with (/sup 111/In)oxine  

The successful labeling of rabbit peripheral blood neutrophils with (/sup 111/In)oxine is reported here. Standard techniques for preparation of rabbit neutrophils, while acceptable for maintenance of in vitro function, rendered the neutrophils ineffective for in vivo use after labeling with /sup 111/In. Specifically, rabbit neutrophils were sensitive to the use of hypotonic shock for red cell elimination, centrifugation into a button during preparation, and the presence of oxine during chemotaxis in vitro. Using a carefully modified method of neutrophil preparation and labeling, it was found that /sup 111/In-labeled rabbit neutrophils retained normal in vitro function, including chemotaxis. In addition, using this method, 34% +- 5% of labeled neutrophils were recoverable in peripheral blood 5 min after intravenous injection. The half-life of circulating radiolabeled neutrophils was 5.6 +- 2 h. Continuous external imaging of radiolabeled neutrophils after intravenous injection showed initial lung uptake, followed by rapid clearance of radioactivity in the lungs (50% clearance in 10.5 +- 3.3 min.). Hepatic radioactivity was maximal by 30 min after injection and thereafter slowly declined. Finally, it was found that /sup 111/In-labeled rabbit neutrophils migrated to sites of artificially induced inflammation. These findings indicate that /sup 111/In-labeled rabbit neutrophils, if prepared under optimal conditions, should provide a useful tool for investigating the fate of neutrophils in experimental inflammatory conditions in this animal.

12

Evaluation of induced radioactivity in 10 MeV-electron irradiated spices, (1); [gamma]-ray measurement  

Black pepper, white pepper, red pepper, ginger and turmeric were irradiated with 10 MeV electrons from a linear accelerator to a dose of 100 kGy and radioactivity was measured in order to estimate induced radioactivity in the irradiated foods. Induced radioactivity could not be detected significantly by [gamma]-ray spectrometry in the irradiated samples except for spiked samples which contain some photonuclear target nuclides in the list of photonuclear reactions which could produce radioactivity below 10 MeV. From the amount of observed radioactivities of short-lived photonuclear products in the spiked samples and calculation of H[sub 50] according to ICRP Publication 30, it was concluded that the induced radioactivity and its biological effects in the 10 MeV electron-irradiated natural samples were negligible in comparison with natural radioactivity from [sup 40]K contained in the samples. (author).

13

Evaluation of induced radioactivity in 10 MeV electron-irradiated spices  

In order to make clear appreciation to induced radioactivity in the irradiated foods, photonuclear reactions which could produce radioactivity at energies up to 10 MeV were listed up from elemental compositions of black pepper, white pepper, red pepper, ginger and turmeric. The samples were irradiated with 10 MeV electron from a linear accelerator to a dose of 100 kGy and radioactivity was measured. Induced radioactivity could not be detected significantly by gamma-ray spectrometry and beta-ray counting in the irradiated samples except for spiked samples which contain some photonuclear target nuclides in the list. From the amount of observed radioactivities of short-lived photonuclear products in the spiked samples and calculation of H[sub 50] according to ICRP Publication 30, it was concluded that the induced radioactivity and its biological effects in the 10 MeV electron-irradiated natural samples were negligible in comparison with natural radioactivity from [sup 40]K contained in the samples. (J.P.N.).

14

Survey monitoring of environmental radioactivity in Daejeon area  

Systematic understanding of the distribution of environmental radioactivity and radiation level in Daejeon, including Chungchung area, in normal circumstance, and rapid detection of unusual variation of the radiation level in emergency situation thereby ensure public safety are the objectives of this project to be carried out. This report summarizes and interprets environmental radiation/radioactivity monitoring data obtained at Daejeon Radiation Monitoring Station in 2001. In conclusion, the natural environmental radiation level in Daejeon area has been preserved as usual and no significant artificial enhancement in environmental radioactivity was observed during the course of this survey and monitoring period.

15

Survey monitoring of environmental radioactivity in Daejeon area  

Systematic understanding of the distribution of environmental radioactivity and radiation level in Taejon, including Chungchung area, in normal circumstance, and rapid detection of unusual variation of the radiation level in emergency situation thereby ensure public safety are the objectives of this project to be carried out. This report summarizes and interprets environmental radiation/radioactivity monitoring data obtained at Taejon Radiation Monitoring Station in 2000. In conclusion, the natural environmental radiation level in Taejon area has been preserved as usual and no significant artificial enhancement in environmental radioactivity was observed during the course of this survey and monitoring period.

16

Survey monitoring of environmental radioactivity in Daejeon area  

Systematic understanding of the distribution of environmental radioactivity and radiation level in Daejeon, including Chungchung area, in normal circumstance, and rapid detection of unusual variation of the radiation level in emergency situation thereby ensure public safety are the objectives of this project to be carried out. This report summarizes and interprets environmental radiation/radioactivity monitoring data obtained at Daejeon Radiation Monitoring Station in 2002. In conclusion, the natural environmental radiation level in Daejeon area has been preserved as usual and no significant artificial enhancement in environmental radioactivity was observed during the course of this survey and monitoring period.

17

Isotope and machine sources for food irradiation  

Artificial radioactive sources as Co-60 and Cs- 137 are produced by bombarding Co-59 with neutrons in a nuclear reactor and by chemical separation of spent nuclear fuel respectively. Both radioactive sources emit very high frequency electromagnetic radiation called y-rays. This highly penetrating radiation is employed for preservation of food. Each y-ray emitted from a radioactive source transports energy from the source to the irradiated food. Penetration of y-rays and their intensity depend on y-energy. Inside this study the advantages and disadvantages of both sources are compared. (Author)

18

Survey monitoring of environmental radioactivity in Daejeon area  

Systematic understanding of the distribution of environmental radioactivity and radiation level in Daejeon, including Chungchung area, in normal circumstance, and rapid detection of unusual variation of the radiation level in emergency situation thereby ensure public safety are the objectives of this project to be carried out. This report summarizes and interprets environmental radiation/radioactivity monitoring data obtained at Daejeon Radiation Monitoring Station in 2002. In conclusion, the natural environmental radiation level in Daejeon area has been preserved as usual and no significant artificial enhancement in environmental radioactivity was observed during the course of this survey and monitoring period.

19

In vitro assay of thrombolysis with /sup 125/I-fibrinogen  

A radioactive method for assaying thromobolysis in vitro is described. Artificial thrombi were labelled with /sup 125/I-fibrinogen and the percentage lysis occurring in blood samples containing a thrombolytic agent was determined. This method was found to be more sensitive, accurate and convenient than an alternative assay method based on the weighing of fixed thrombi after treatment with a thrombolytic agent.

20

Study, assessment of radioactive dose on China's population  

The national population dose is defined as the radioactive dose from both natural and artificial sources which is received by the entire Chinese population. The necessity and prospects for developing ways to assess China's national population dose and some noteworthy problems in this area are described.

 
 
 
 
21

Radioactivity of dates in Saudi Arabia  

Samples of dates from three regions of Saudi Arabia were measured for the radioactivity of both natural and artificial origins. The results were compared with gross ..beta.. and /sup 187/Cs activity of coffee beans produced in different countries. No significant activity in date samples was detected.

22

Complementary results of radioactivity analysis made in Corsica following the navigation incident of the Uss Hartford submarine; Resultats complementaires des analyses de radioactivite effectuees en Corse suite a l'incident de navigation du sous-marin USS Hartford  

The results of analysis made by the Institute of radiation protection and nuclear safety in the area of the Bonifacio estuary do not reveal any increase of artificial radioactivity following the navigation incident of the Uss Hartford submarine. They confirm the previous published results. (N.C.)

23

NATURAL RADIOACTIVITY AS CLIMATE FACTOR AND FISSION PRODUCT ACTIVITY FROM ATOMIC BOMB EXPERIMENTS IN ATMOSPHERIC AEROSOLS IN THE LOWER AIR IN AUTUMN 1961  

For two different kinds of atmosphere situations (for times of 4 days) before resumption of the Russian atomic bomb tests in September 1961, mean daily variations of the natural aerosol activity were calculated and compared with the daily variations of the aerosol activity after appearance of the fission products from the bomb tests after September 1, 1961 in the northwest region of Germany for two similar atmospheric situations. Results showed that the artificial radioactivity did not exhibit the same daily variations as the natural aerosol radioactivity and about 14 days after the resumption of the bomb tests, on the average, a proportionate increase in the natural activity of the aerosols was observed. The usefulness of monitoring the aerosol activity for control systems in reactor and nuclear research installations for recognition of artificial radioactive particles is discussed. (tr-auth)

24

Progress in the controlled propagation of Glaria Lazera (Cuvier et Valenciennes)  

Subsequent to the existing work concerning the culture of Clarias lazera (C. et v.) it was tried to increase the effectiveness of it's propagation through artificial reproduction. Hypophysation to induce the release of eggs followed by stripping and artificial fertilization gave promising results. T...

25

A photocatalyst/enzyme couple that uses solar energy in the asymmetric reduction of acetophenones.  

Artificial Photosynthesis System: A novel photocatalyst/enzyme-coupled artificial photosynthesis system harvests solar energy as seen in green plants through the combination of photocatalysis and biocatalysis and induces asymmetry in an achiral substrate (see picture; ADPR=adenosine diphosphate ribose, NADP=nicotinamide adenine dinucleotide phosphate). PMID:23065709

26

Dissociation of vertical semiconductor diatomic artificial molecules  

We investigate the dissociation of few-electron circular vertical semiconductor double quantum dot artificial molecules at 0 T as a function of interdot distance. A slight mismatch introduced in the fabrication of the artificial molecules from nominally identical constituent quantum wells induces lo...

27

PLGA nanoparticle-mediated delivery of tumor antigenic peptides elicits effective immune responses.  

The peptide vaccine clinical trials encountered limited success because of difficulties associated with stability and delivery, resulting in inefficient antigen presentation and low response rates in patients with cancer. The purpose of this study was to develop a novel delivery approach for tumor antigenic peptides in order to elicit enhanced immune responses using poly(DL-lactide-co-glycolide) nanoparticles (PLGA-NPs) encapsulating tumor antigenic peptides. PLGA-NPs were made using the double emulsion-solvent evaporation method. Artificial antigen-presenting cells were generated by human dendritic cells (DCs) loaded with PLGA-NPs encapsulating tumor antigenic peptide(s). The efficiency of the antigen presentation was measured by interferon-? ELISpot assay (Vector Laboratories, Burlingame, CA). Antigen-specific cytotoxic T lymphocytes (CTLs) were generated and evaluated by CytoTox 96(®) Non-Radioactive Cytotoxicity Assay (Promega, Fitchburg, WI). The efficiency of the peptide delivery was compared between the methods of emulsification in incomplete Freund's adjuvant and encapsulation in PLGA-NPs. Our results showed that most of the PLGA-NPs were from 150 nm to 500 nm in diameter, and were negatively charged at pH 7.4 with a mean zeta potential of -15.53 ± 0.71 mV; the PLGA-NPs could be colocalized in human DCs in 30 minutes of incubation. Human DCs loaded with PLGA-NPs encapsulating peptide induced significantly stronger CTL cytotoxicity than those pulsed with free peptide, while human DCs loaded with PLGA-NPs encapsulating a three-peptide cocktail induced a significantly greater CTL response than those encapsulating a two-peptide cocktail. Most importantly, the peptide dose encapsulated in PLGA-NPs was 63 times less than that emulsified in incomplete Freund's adjuvant, but it induced a more powerful CTL response in vivo. These results demonstrate that the delivery of peptides encapsulated in PLGA-NPs is a promising approach to induce effective antitumor CTL responses in vivo. PMID:22619507

28

Relevance of Weil Felix test in diagnosis of scrub typhus in India  

The peptide vaccine clinical trials encountered limited success because of difficulties associated with stability and delivery, resulting in inefficient antigen presentation and low response rates in patients with cancer. The purpose of this study was to develop a novel delivery approach for tumor antigenic peptides in order to elicit enhanced immune responses using poly(DL-lactide-co-glycolide) nanoparticles (PLGA-NPs) encapsulating tumor antigenic peptides. PLGA-NPs were made using the double emulsion-solvent evaporation method. Artificial antigen-presenting cells were generated by human dendritic cells (DCs) loaded with PLGA-NPs encapsulating tumor antigenic peptide(s). The efficiency of the antigen presentation was measured by interferon-? ELISpot assay (Vector Laboratories, Burlingame, CA). Antigen-specific cytotoxic T lymphocytes (CTLs) were generated and evaluated by CytoTox 96® Non-Radioactive Cytotoxicity Assay (Promega, Fitchburg, WI). The efficiency of the peptide delivery was compared between the methods of emulsification in incomplete Freund’s adjuvant and encapsulation in PLGA-NPs. Our results showed that most of the PLGA-NPs were from 150 nm to 500 nm in diameter, and were negatively charged at pH 7.4 with a mean zeta potential of ?15.53 ± 0.71 mV; the PLGA-NPs could be colocalized in human DCs in 30 minutes of incubation. Human DCs loaded with PLGA-NPs encapsulating peptide induced significantly stronger CTL cytotoxicity than those pulsed with free peptide, while human DCs loaded with PLGA-NPs encapsulating a three-peptide cocktail induced a significantly greater CTL response than those encapsulating a two-peptide cocktail. Most importantly, the peptide dose encapsulated in PLGA-NPs was 63 times less than that emulsified in incomplete Freund’s adjuvant, but it induced a more powerful CTL response in vivo. These results demonstrate that the delivery of peptides encapsulated in PLGA-NPs is a promising approach to induce effective antitumor CTL responses in vivo. PMID:16941792

29

Spectroscopic investigations on the complexation of Cm(III) and Eu(III) with organic model ligands and their binding mode in human urine (in vitro); Spektroskopische Untersuchungen zur Komplexbildung von Cm(III) und Eu(III) mit organischen Modellliganden sowie ihrer chemischen Bindungsform in menschlichem Urin (in vitro)  

In case of incorporation, trivalent actinides (An(III)) and lanthanides (Ln(III)) pose a serious health risk to humans. An(III) are artificial, highly radioactive elements which are mainly produced during the nuclear fuel cycle in nuclear power plants. Via hazardous accidents or nonprofessional storage of radioactive waste, they can be released in the environment and enter the human food chain. In contrast, Ln(III) are nonradioactive, naturally occurring elements with multiple applications in technique and medicine. Consequently it is possible that humans get in contact and incorporate both, An(III) and Ln(III). Therefore, it is of particular importance to elucidate the behaviour of these elements in the human body. While macroscopic processes such as distribution, accumulation and excretion are studied quite well, knowledge about the chemical binding form (speciation) of An(III) and Ln(III) in various body fluids is still sparse. In the present work, for the first time, the speciation of Cm(III) and Eu(III) in natural human urine (in vitro) has been investigated spectroscopically and the formed complex identified. For this purpose, also basic investigations on the complex formation of Cm(III) and Eu(III) in synthetic model urine as well as with the urinary relevant, organic model ligands urea, alanine, phenylalanine, threonine and citrate have been performed and the previously unknown complex stability constants determined. Finally, all experimental results were compared to literature data and predictions calculated by thermodynamic modelling. Since both, Cm(III) and Eu(III), exhibit unique luminescence properties, particularly the suitability of time-resolved laser-induced fluorescence spectroscopy (TRLFS) could be demonstrated as a method to investigate these metal ions in untreated, complex biofluids. The results of this work provide new scientific findings on the biochemical reactions of An(III) and Ln(III) in human body fluids on a molecular scale and contribute to a better understanding of the known macroscopic effects of these elements. Furthermore, they are the basis of subsequent in vivo investigations. (orig.)

30

Survey monitoring of environmental radioactivity in Daegu area  

The objectives of the project are to monitor an abnormal radiation level in Taegu and Kyungpook region, and to enhance our ability to prepare for the radiological emergency situation by establishing the radioactivity monitoring system in Taegu and Kyungpook region. Gross beta activities were measured and gamma radionuclides were analysed for the environmental samples of air-borned dust. precipitation. fallout and drinking water collected in Taegu radioactivity monitoring center. and gamma exposure rates were also measured. To establish the basic data base on the environmental radioactivity, gamma radionuclide analyses were carried out for the samples of soil, drinking water, grain, vegetable, milk, and fish which were obtained from 31 different areas, and the spatial gamma exposure rates from 61 different points were also measured in Taegu and Kyungpook region. In conclusion, it didn't appear any evidence for newly pollution of artificial radioactivity in Taegu and Kyungpook region.

31

[Assessment of modern radioecological situation at nuclear explosion "Chagan" (Balapan Site, Semipalatinsk Nuclear Test Site, Kazakhstan)].  

Results on estimation of modern radioecological situation at nuclear explosion "Chagan" based on large-scale cartographic studies (1:25000) of a test area (4 km2) are presented. Maximum gamma-irradiation doses were observed at bulk of ground surrounded a crater and at radioactive fall-outs extended to the North-East and to the SouthWest from the crater. Based on data on artificial radionuclide specific activity most part of soil samples were attributed to radioactive wastes according to IAEA (1996) and OSPORB (1999). Natural decrease of soil radioactivity up to safety level due to 60Co, 137Cs, 90Sr, 152Eu, 154Eu radioactive decay and 241Am accumulation-decay will not take place within the next 60 years at the studied area. PMID:19004330

32

Alternative Therapies  

... treatment impairs the underlying disease or pulmonary function. Hypnosis. An artificially induced dream state that leaves the person open to suggestion, hypnosis is a legitimate technique to help people manage ...

33

Photorealism aftereffect.  

This study reports a novel visual aftereffect for photorealism judgments. Participants observed image sequences where a photograph was gradually transformed into an artificial image (a painting or a sketch). Their task was to choose the image that was the category boundary between the photograph and the artificial image among the frames of each image sequence. This task was performed before and after observing photographs or artificial images for 1 min. The chosen images were less photorealistic after the observation of artificial images, suggesting an aftereffect for photorealism judgments. However, observation of photographs did not induce an aftereffect. It is known that the observation of the norms for perceptual judgments (e.g., the prototypical face for facial judgments) does not induce aftereffects. Thus, these results suggest that photorealistic images serve as the norm for the perceptual judgment of photorealism. The human visual system may represent the photorealism of artificial images as a deviation from photorealistic images. PMID:20652589

34

Radiation control of the Rhine channel sediments, upstream and downstream of the Fessenheim CNPE; Controle de la radioactivite des sediments du Canal du Rhin, en amont et en aval du CNPE de Fessenheim  

In the framework of the Fessenheim CNPE control, the Commission of the Local Survey (CLS) decided to realize studies independent from the operating. The CRII-RAD laboratory realized this study on the environmental impacts of the nuclear power plant releases. The objectives, the methodology and the results are described. They concern the natural and artificial radioactivity, the last results of 1989, the comparison with the IPSN analysis results of 1998, the detected artificial gamma radionuclides origin and the measure interest of pure beta emitters. Tables of results for all elements are given. (A.L.B.)

35

Artificial intelligence methods applied for quantitative analysis of natural radioactive sources  

Artificial neural network (ANN) represents one of artificial intelligence methods in the field of modeling and uncertainty in different applications. The objective of the proposed work was focused to apply ANN to identify isotopes and to predict uncertainties of their activities of some natural radioactive sources. The method was tested for analyzing gamma-ray spectra emitted from natural radionuclides in soil samples detected by a high-resolution gamma-ray spectrometry based on HPGe (high purity germanium). The principle of the suggested method is described, including, relevant input parameters definition, input data scaling and networks training. It is clear that there is satisfactory agreement between obtained and predicted results using neural network.

36

Hypothetical HTLV-I induction by ionizing radiation.  

Some laboratories have reported HTLV-I genome integration in cancer patients diagnosed with neoplasms of cervix and uterus. Usually, cancer patients undergo radiotherapy besides chemotherapy and surgery. It is hypothesized that radiation exposure would induce HTLV-I genome generation/activation, nevertheless there is not any report on experimental procedures trying to demonstrate HTLV-I gene expression in cells exposed to ionizing radiation. Anyway, earlier experimental works by Lieberman and Kaplan in 1959 succeeded to isolate retroviral particles, the radiation leukemia virus (RadLV), from thymic lymphomas of X-ray-irradiated C57BL/Ka mice, assuming that RadLV activated in the host by ionizing radiation, is released and transported to the thymus, where lymphoblasts, generated during the postradiation recovery phase, constitute an optimal target cell population for both replication of and eventual transformation by virus. Recent studies claim that besides RadLV, another retrovirus (RadLV-0) also induced by ionizing radiation is expressed and would be responsible for transformed cells of bone marrow origin. Epidemiological studies coincidentally point out to high incidence of HTLV-I infection in geographic areas displaying significant levels of radioactivity contamination as in Central Africa, Japan Islands and Mururoa Atoll. In our research work, we detected HTLV-I antibodies and viral genome integration in cancer patients of cervix and uterus and health care workers, whose had been exposed to ionizing radiation during radiotherapeutic procedures. Recombinational events among endogenous retrovirus and other retrogenic elements in the host cell genome under the bombardment of ionizing radiation from different sources could have optimized the phenomena occurrence or even ignited them to happen, generating HTLV-I genome, related viral peptides and virions. Therefore, it is feasible that exposure to ionizing radiation during therapeutic procedures could generate HTLV-I genome or induce the virus to be expressed in cells of cancer patients submitted to radiotherapy as also in healthy subjects under the same conditions, in artificial or natural radiation environment. PMID:16540259

37

Nuclear physics. Fourth edition  

This book is designed to be an extension of the introductory college physics course into the realm of atomic physics: It should give students a proficiency in this field comparable to their proficiency in mechanics, heat, sound, light and electricity. Topics included: the atomic view of matter; the atomic view of electricity; the atomic view of radiation; the atomic models of Rutherford and Bohr; relativity; x-rays; waves and particles; quantum mechanics; the atomic view of solids; natural radioactivity; nuclear reactions and artificial radioactivity; nuclear energy; and high-energy physics.

38

Radon, its ancestors and descendants. On the evolution of concepts on radioactivity; Radon, seine Vorfahren und Nachkommen. Evolutionsphysikalische Betrachtungen  

Radon has - among all radionuclides, natural and artificial ones - unique properties. Radon represents paradigmatically two principles in the evolution of physical concepts from complexity to simplicity and from simplicity to complexity, which were active in the early years of radioactivity research. The two principles are: 1. The principle of a separation, collection and concentration of a simple component from a complex matrix. 2. The principle of a spontaneous regeneration of a complex matrix from a simple component. The Philion Experimental-Set presents playfully these principles and much more of radioactivity/nuclear physics in schools. It is now available in a new, improved version. (orig.)

39

Gross alpha radioactivity of drinking water in Venezuela  

Bottled mineral water is consumed by a large population in Venezuela. The alpha emitters concentration was measured in samples of bottled water and water springs collected near the surface. Approximately 30% of the total mineral water suppliers was monitored. a database on natural and artificial radioactivity in drinking water was produced. Results indicate that 54% of the waters sampled contain a total alpha radioactivity of less than 0.185 Bql{sup -1} and only 12% above 0.37 Bql{sup -1}. Our results revealed a total annual dose of 2.3 mSv year{sup -1}. (author).

40

Atom history, from intuitive ideas to reality; Histoire de l'atome de l'intuition a la realite  

This book gathers the ground scientific texts that have stood out as milestones in the way scientists have built their understanding of the atom over centuries. From the very intuitive ideas of Greek philosophers to the most recent results on ultra-cold atoms, via the discovery of natural radioactivity or the existence of the neutron, about 55 articles written by prestigious physicists have been organized into 16 chapters. Each chapter being dedicated to a topic such as molecules, spectroscopy, electrons, X-rays, atom mass, artificial radioactivity..., begins with a commentary that draws the scientific context of that time, describes the links between the articles and highlights the importance of the discoveries. (A.C.)

 
 
 
 
41

Is it necessary to raise awareness about technologically enhanced naturally occurring radioactive materials?  

Since radiation risks are usually considered to be related to nuclear energy, the majority of research on radiation protection has focused on artificial radionuclides in radioactive wastes, spent nuclear fuel or global fallout caused by A-bomb tests and nuclear power plant failures. Far less attention has been paid to the radiation risk caused by exposure to ionizing radiation originating from natural radioactivity enhanced due to human activity, despite the fact that technologically enhanced naturally occurring radioactive materials are common in many branches of the non-nuclear industry. They differ significantly from "classical" nuclear materials and usually look like other industrial waste. The derived radiation risk is usually associated with risk caused by other pollutants and can not be controlled by applying rules designed for pure radioactive waste. Existing data have pointed out a strong need to take into account the non-nuclear industry where materials containing enhanced natural radioactivity occur as a special case of radiation risk and enclose them in the frame of the formal control. But up to now there are no reasonable and clear regulations in this matter. As a result, the non-nuclear industries of concern are not aware of problems connected with natural radioactivity or they would expect negative consequences in the case of implementing radiation protection measures. The modification of widely comprehended environmental legislation with requirements taken from radiation protection seems to be the first step to solve this problem and raise awareness about enhanced natural radioactivity for all stakeholders of concern. PMID:19809704

42

Natural decrease of the intensity level of artificial radioactive isotopes in the Barents Sea  

The results of radioecological investigations carried out within the framework of the Russian-Finnish high-latitude expedition in 2007 are presented. The characteristics of the present-day accumulation level of the significant radioecological isotopes 137Cs, 90Sr and 239,240Pu in the Barents Sea are described. The comparative analysis is performed for the radiation pollution of the environment in the 1980s and 1990s and in the first decade of the 21st century. Natural purification processes in the marine environment are the main factors of the decrease in the intensity level of artificial radioactive isotopes. These processes include repeated dilution, nuclear decay, occlusion by sediments and suspended solid material, and accumulation by aquatic inhabitants. A stable decreasing trend is observed for the intensity level of artificial radioactive isotopes in the Barents Sea.

43

Distribution of natural and anthropogenic radionuclides in heavy rainfall areas in Jordan  

Soil is the main reservoir of both natural and artificial radionuclides, which are transported to the human body through the food chain. Thus, assessment of the level of radioactivity in soil is of crucial importance. Artificial radionuclide concentrations in soil depend heavily on rainfall and weather conditions. In this study, the soil of the Ras Muneef area, which has the highest rainfall in Jordan, was investigated for its natural and anthropogenic radioactive content. The area was divided into four sectors and in each sector three locations were investigated depending on the land use: undisturbed, cultivated or residential. The depth profile of 137Cs was investigated and found to depend on the land use. In the undisturbed soils, two types of depth profiles were identified: Gaussian an...

44

Radiochemical separation of actinides for their determination in environmental samples and waste products  

The determination of low level activities of actinides in environmental samples and waste products makes high demands on radiochemical separation methods. Artificial and natural actinides were analyzed in samples form the surrounding areas of NPP and of uranium mines, incorporation samples, solutions containing radioactive fuel, solutions and solids resutling from the process, and in wastes. The activities are measured by {alpha}-spectrometry and {gamma}-spectrometry. (DG)

45

Low-energy neutrino-electron scattering as a standard model probe: The potential of LENA as case study  

Several proposals for studying neutrinos with large detectors are currently under discussion. We suggest that they could provide a precise measurement of the electroweak mixing angle as well as a probe for new physics, such as nonstandard neutrino interactions, and the electroweak gauge structure. We illustrate this explicitly for the case of the LENA proposal, either with an artificial radioactive source or by using the solar neutrino flux.

46

The thorium alloys in aeronautics: from material analysis to regulation application; Les alliages thories de l'aeronautique: de l'analyse du materiel a l'application de la reglementation  

The thorium handled in aeronautics is a mixing in variable proportion of different thorium isotopes and its daughter products, but the regulation considers only two alpha emitters (Th-232 and Th-228): the thorium being considered as a natural radioactive substance, the legislation and the activities authorised are less restrictive than for artificial elements, it is a paradoxical situation because the thorium has the annual limit of intake the lowest of the regulation. (N.C.)

47

From the discovery of the neutron to the discovery of nuclear fission  

The history of nuclear physics from 1932 to 1939 is reviewed. Especially considered are the discovery of the neutron, the first studies of nuclear reactions by accelerators, the development of the neutrino hypothesis for the description of the beta decay, the production of artificial radioactivity, the study of reactions with slow neutrons, the first studies of neutron resonances and isomeric states, neutron diffraction, the development of theories of nuclear forces and the discovery of fission.

48

Radioactivity and food  

Two topics relating to radioactivity and food are discussed: food irradiation for preservation purposes, and food contamination from radioactive substances. Food irradiation involves the use of electromagnetic energy (x and gamma rays) emitted by radioactive substances or produced by machine in order to destroy the insects and microorganisms present and prevent germination. The sanitary and economic advantages of treating food in this way are discussed. Numerous studies have confirmed that under strictly controlled conditions no undesirable changes take place in food that has been irradiated nor is radioactivity induced. Reference is made to the accident at the Chernobyl nuclear power station, which aroused public concern about irradiated food. The events surrounding the accident are reviewed, and its consequences with regard to contamination of different foods with radioactive substances, particularly iodine-131 and cesium-137, are described. Also discussed are the steps that have been taken by different international organizations to set limits on acceptable radioactivity in food.15 references.

49

Studies of induced radioactivity at the AGS  

With the goals of higher proton intensities, along with the many modes the AGS now runs and those being commissioned to run, we have begun detailed studies of the beam induced radioactivity in the AGS.

50

Radiation Damage of Electronic and Optoelectronic Devices in Space  

Tsukuba, Japan, October 11-13, 2000. Radiation Damage of ... energy protons are the dominant source of ionizing radiation. .... which are not included in the standard models, can ... for the induced radioactivity to die down to levels that allow ...

51

Overview of Attached Payload Accommodations and Environments ...  

7121 Standard Drive .... Figure 3-1: JEM-EF under construction at JAXA Facility in Tsukuba, Japan. 14 ..... source. During the assembly of ISS, electrical power generation hardware ..... protons, the nuclei-induced radioactivity in most materials.

52

The prediction of induced activity levels in and around NIMROD  

Comparisons are reported between measured and predicted levels of induced radioactivity for a number of irradiation conditions. Good agreement was found between experimental measurements and fairly simple methods of prediction developed at CERN.

53

Gas density detector for use in space  

radioactively-induced currents in ionization chambers and proportional counters .... Argon. Neon. Krypton. Xenon. Air. Carbon Dioxide. Methane. 15.4. 24.6. 15.5. 12.2. 15.8. 21.6 ..... per unit volume, and a is the coefficient of recombination, n ...

54

Inducible and Constitutive ?-Galactosidase Formation in Cells Recovering from Protein Synthesis Inhibition1  

Inducible and constitutive ?-galactosidase formation and radioactive amino acid incorporation were measured in cells recovering from various treatments which inhibit protein synthesis in the cell. Undelayed ?-galactosidase formation was found in stringent auxotrophs recovering from amino acid starva...

55

Breast feeding by urban mothers.  

500 Bengali mothers mostly from the middle class attending the well-baby clinic of a Calcutta hospital were studied to determine the extent of breastfeeding practiced and the factors influencing the choice of artificial feeding. Of the mothers choosing artificial foods, 66.4% combined them with breastfeeding before the child was 3 months old. 4.4% made a complete switch to artificial feeding at 3 months. Only 1.6% did not breast feed their babies at all. The commonest factors influencing choice of artificial feeding, especially among younger women of lower socioeconomic background, who had a sufficient supply of breast milk, were misconception or wrong advice. With mothers of older age groups and with higher education, insufficient supply of breast milk, possibly due to psychological blocks or in consequence of working status, and in some cases induced by early separation of babies, was responsible for artificial feeding. PMID:701818

56

Environmental Monitoring according to the Euratom treaty of the environmental radioactivity in Sweden, 1997 to 2001; Miljoeoevervakning enligt Euratomfoerdraget av joniserande straalning i miljoen i Sverige aar 1997 till 2001  

This report presents the results for the years 1997 to 2001 from the environmental monitoring required by article 36 of the Euratom treaty. A monitoring programme has existed since the late 1950s. Monitoring is currently performed continuously on radioactive substances in outdoor air and of ambient gamma dose rates outdoors. Regular measurements are performed on radioactive substances in surface and drinking water, milk, mixed diet and in the human body. The programme considers both naturally and artificially occurring radioactive substances, with an emphasis on the latter. The internal radiation dose from {sup 137}Cs, {sup 90}Sr and {sup 3}H in foodstuffs for year 2001 was 0.005 mSv/year for an average Swede; 0.0002 mSv/year came from {sup 137}Cs, {sup 90}Sr and {sup 3}H in drinking water and 0.0006 mSv/year came from {sup 137}Cs and {sup 90}Sr in milk. Large variations occur in doses; for persons consuming nature food products, the internal dose can be up to 0.2 mSv/year in fall-out stricken areas. The internal dose for an average Swede for the year 2001 from inhaled and ingested artificially occurring radioactive substances was 0.1 percent of the total dose received. An average Swede is estimated to get 4 mSv/year from the sum of all radiation.

57

Physics and Technology for the Next Generation of Radioactive Ion Beam Facilities: EURISOL  

Since the discovery of artificial radioactivity in 1935, nuclear scientists have developed tools to study nuclei far from stability. A major breakthrough came in the eighties when the first high energy radioactive beams were produced at Berkeley, leading to the discovery of neutron halos. The field of nuclear structure received a new impetus, and the major accelerator facilities worldwide rivalled in ingenuity to produce more intense, purer and higher resolution rare isotope beams, leading to our much improved knowledge and understanding of the general evolution of nuclear properties throughout the nuclear chart. However, today, further progress is hampered by the weak beam intensities of current installations which correlate with the difficulty to reach the confines of nuclear binding where new phenomena are predicted, and where the r-process path for nuclear synthesis is expected to be located. The advancement of Radioactive Ion Beam (RIB) science calls for the development of so-called next-generation facil...

58

E.X.T.R.E.M.E. project. Launch; Projet EXTREME. Rapport de lancement  

Due to the drastic decrease in artificial radioactivity levels from primary sources such as atmospheric fallout or industrial releases, radioactive storages constituted in the past within several environmental compartments act today as non negligible secondary sources. These delayed sources are particularly active during extreme weather or climatic events such as rainfalls or atmospheric deposits, floods, storms, etc...that may remove important mass, generate activity levels higher than the predicted ones from modeling based on mean transfer process, and produce in a couple of hours or days fluxes similar to those accrued over several month or years. Extreme aims at assessing the consequences on man and its environment of natural events that generate extreme radioactive stocks and/or fluxes within several environmental compartments (atmosphere, soils, rivers, coastal marine environment and deep sea areas). (authors)

59

Birds as objects in bioindication of radioactive pollution.  

This article is a review the recent results of research in the accumulation of natural and artificial radionuclides in birds from Russia (Adigea, Krasnodar, Rostov, Astrahan and Moscow regions, Novaya Zemlya isles), Ukraine, Vietnam, Poland, Ethiophia and Mongolia after global precipitation and local pollution, such as in the East-Urals radioactive region and radioactive zones after the Chernobyl accident. Resident birds reflect local level of radionuclide contamination. The 90Sr concentration in the food of the Pied Flycatcher had a tendency to increase in dependent of age. The Common Jay and the Mallard were the most contaminated with 137Cs in the Bryansk region. The total content of various radio-isotopes of plutonium in bird bones from Southwest Russia were hundred and thousand times more, than in Mongolia. Activity levels in specimens from Ethiopia bear record to Ethiopia can notbe a "pure" control site in radioecological research and radioactive background since it does not significantly differ from Turkmenia and Mongolia. PMID:10574436

60

Natural activities of 40K, 238U and 232Th in elephant grass (Pennisetum purpureum) in Ibadan metropolis, Nigeria.  

Samples of elephant grass collected at some pasturing farmlands across different locations in Ibadan metropolis were analyzed for their natural radioactivity concentrations due to 40K, 238U and 232Th radionuclides. Radioactivity measurements were carried out using gamma-ray spectroscopy. The average radioactivity concentration of 40K was found to be 25.7+/-5.5 Bq kg(-1) for 238U and 33.4+/-3.9 Bq kg(-1) for 232Th. The radiological health implication to the population that may result from these values is found to be very low and almost insignificant. No artificial radionuclide, however, was detected in any of the samples, hence, measurements have been taken as representing baseline values of these radionuclides in the grass in the metropolis. PMID:15465183

 
 
 
 
61

Radiation-induced defects in clay minerals: A review  

Extensive information has been collected on radiation effects on clay minerals over the last 35 years, providing a wealth of information on environmental and geological processes. The fields of applications include the reconstruction of past radioelement migrations, the dating of clay minerals or the evolution of the physico-chemical properties under irradiation.The investigation of several clay minerals, namely kaolinite, dickite, montmorillonite, illite and sudoite, by Electron Paramagnetic Resonance Spectroscopy has shown the presence of defects produced by natural or artificial radiations. These defects consist mostly of electron holes located on oxygen atoms of the structure. The various radiation-induced defects are differentiated through their nature and their thermal stability. Most of them are associated with a ? orbital on a Si-O bond. The most abundant defect in clay minerals is oriented perpendicular to the silicate layer. Thermal annealing indicates this defect in kaolinite (A-center) to be stable over geological periods at ambient temperature. Besides, electron or heavy ion irradiation easily leads to an amorphization in smectites, depending on the type of interlayer cation. The amorphization dose exhibits a bell-shaped variation as a function of temperature, with a decreasing part that indicates the influence of thermal dehydroxylation. Two main applications of the knowledge of radiation-induced defects in clay minerals are derived: (i) The use of defects as tracers of past radioactivity. In geological systems where the age of the clay can be constrained, ancient migrations of radioelements can be reconstructed in natural analogues of high level nuclear waste repositories. When the dose rate may be assumed constant over time, the paleodose is used to date clay populations, an approach applied to fault gouges or laterites of the Amazon basin. (ii) The influence of irradiation over physico-chemical properties of clay minerals. An environmental application concerns the performance assessment of the engineered barrier of nuclear waste disposals. In case of a leakage of transuranic elements from the radioactive waste form, alpha recoil nuclei can amorphize smectite after periods of the order of 1000 years according to a worst case scenario, whereas amorphization from ionizing radiation is unlikely. As amorphization greatly enhances the dissolution kinetics of smectite, the sensitivity of the smectites must be taken into account in the prediction of the long term behavior of engineered barriers.

62

NATURALLY OCCURRING AND ARTIFICIALLY INDUCED MUTATIONS IN MAIZE  

Results are reported from artificial mutagenesis experiments in maize designed to investigate the nature of induced and inheritable variety. Results are summarized for the scoring about 10,000 F/sub 1/ ears for types and frequency of endosperm mutations following chemical and x radiation treatment. Differences in response to x radiation and chemical mutagens are discussed. Evidence is presented for an artificially obtained back mutation in maize. (C.H.)

63

Artificial Infection by Water Molds Following Net-shake Treatment in the Platyfish (Xiphophorus maculates)  

Artificial infection with the fungi Saprolegnia diclina BKKU 0506 and Achlya bisexualis BKKU 0616 was induced in the platyfish (Xiphophorus maculates) via exposure to zoospores following artificial injury by scale removal and net-shake or “ami-momi” treatment. The results suggested that ami-momi treatment, but not scale removal, could be used to establish severe fungal infection in small freshwater tropical fish as well as salmonids.   

64

Characterization of the Bacillus subtilis motile system driven by an artificially created proton motive force.  

Transient swimming was induced in energy-depleted cells of Bacillus subtilis by an artificial proton motive force, which was created by valinomycin addition and a pH reduction. This system did not require any ions except protons in the medium. The size of the induced motility was strongly influenced...

65

Inflammation triggers hypoferremia and de novo synthesis of serum transferrin and ceruloplasmin in mice.  

Oil of turpentine was used to induce an artificial inflammation so that we could study its effect on iron metabolism and on synthesis of serum transferrin and ceruloplasmin in mice. It was found that turpentine-induced inflammation triggered the establishment of a hypoferremic state characterized by...

66

Zinc Induction of Testicular Teratomas in Japanese Quail (Coturnix coturnix japonica) after Photo-periodic Stimulation of Testis  

Teratomas have been induced in Japanese quail (Coturnix coturnix Japonica) by intra-testicular injections of 3% zinc chloride solution during a period of testicular growth artificially stimulated by increased photoperiod. These tumours resemble those previously induced by similar methods in domestic...

67

A Review of the Geothermal Reservoir Well Stimulation Program  

Republic Geothermal, Inc., and its subcontractors have planned and executed four experimental fracture stimulation treatments under the Department of Energy-funded Geothermal Reservoir Well Stimulation Program (GRWSP). The 2-year program, begun in February 1979, is Ultimately to include six full-scale field hydraulic and chemical stimulation experiments in geothermal wells. This paper describes the overall program and the four treatments completed to date. The GRWSP is organized into two phases. Phase I consists of literature and theoretical studies, laboratory investigations, and numerical work. The main purpose of this work is to establish the technological bases for geothermal well stimulation design. Phase I1 will include the planning, execution, and evaluation of six well stimulation treatments which utilize the technology developed in Phase I. Two stimulation experiments were performed at the Raft River, Idaho, known geothermal resource area (KGRA) in late 1979. This is a naturally fractured, hard rock reservoir with a relatively low geothermal resource temperature 149 C {+-} (300 F{+-}). A conventional planar hydraulic fracture job was performed in Well RRGP-5 and a ''Kiel'' dendritic, or reverse flow, technique was utilized in Well RRGP-4. In mid-1980, two stimulation experiments were performed at the East Mesa, California, KGRA. The stimulation of Well 58-30 provided the first geothermal well fracturing experience in a moderate temperature, 177 C {+-} (350 F{+-}), reservoir with matrix-type rock properties. The two treatments consisted of a conventional hydraulic fracture of a deep, low-permeability zone and a mini-frac ''Kiel'' treatment of a shallow, high-permeability zone in the same well. The stimulation experiment results to date were evaluated using short-term production tests, conventional pressure transient analysis, interference pressure data, chemical and radioactive tracers, borehole acoustic televiewer surveys and numerical models. This combination of evaluation techniques yielded an interpretation of fracture geometry and productivity enhancement. However, the evaluation of artificially induced fractures in naturally fractured formations was found to lead to possibly non-unique solutions. In all the field experiments, artificial fractures were created and well productivity was increased. A discussion of the prestimulation and poststimulation data and their evaluation are provided for each experiment in this report.

68

Measurement of radioactive nuclides in the `Mayak` region  

The study of environmental contamination caused by anthropogenic impact and, primarily, by radioactive nuclides is one of the main scientific problems facing contemporary science. Radioecological monitoring, decision making on remediation of polluted areas need detailed information about distribution of radioactive nuclides in the terrestrial and aquatic ecosystems, knowledge about radioactive nuclide occurrence forms and migration patterns. Experimental tests of nuclear and thermonuclear weapon in atmosphere and underground, nuclear power engineering and numerous accidents that took place at the nuclear power plants (NPP), unauthorized dump of radioactive materials in various places of the ocean and pouring off the strongly dump of radioactive wastes from ships and submarine equipped with nuclear power engines made artificial radionuclides a constant and unretrievable component of the modern biosphere, becoming an additional unfavorable ecological factor. As regards Former Sovient Union (FSU) the most unfavorable regions are Southern Ural, zones suffered from Chernobyl Accident, Altay, Novaya Zemlya, some part of West Siberia near Seversk (Tomsk-7) and Zheleznogorsk (Krasnoyarsk-26). (orig.)

69

Global balance of Spitsbergen ice mass and prediction of its change due to climatic change  

Different methods of work have been used in order to measure the net balance of large ice masses across Svalbard, to estimate the present balance over the entire archipelago and to predict the change in balance induced by any future climatic change. Present accumulation and ablation are measured by direct glaciological method and recent past mean accumulation is estimated from the detection of dated artificial radioactive layers in 31 shallow ice-cores over 10 glaciers. Based on the analysis of 21 MSS Landsat images, the elevation of the late summer snow line is constructed across Svalbard. Using available echo soundings, stereoscopic analysis of satellite images and aerial photographs together with the bathymetry at glacier fronts, the total calving for the entire archipelago is estimated to be between 7.44 and 9.94 km{sup 3}yr{sup -1}. The net balances measured on 14 different glaciers provided an identical signal across Spitsbergen and the spatial distribution of winter, summer and net balances is well related to the spatial pattern of precipitation and temperature. Except for one, all the studied glaciers have a negative net balance. An empirical model and an energy balance model are constructed for the Broeggerbreen glacier by using climatic data recorded at a neighbouring meteorological station. A net balance of 0.7 m y{sup -1} in water equivalent is predicted per degree of summer temperature rise and, with a decrease of between 0.5-0.7{degree}C in summer temperature, Broeggerbreen will reach a new equilibrium. A reduction of the net balance deficit during the last 23 years is correlated to a slight decrease in summer temperature (-0.3{degree}C) and an increase in winter precipitation (+29%). 30 refs., 9 figs., 3 tabs.

70

National congress of radiation protection - SFRP 2005; Congres National de Radioprotection - SFRP 2005  

The nine tutorial sessions are: first one, the new recommendations of the ICRP; second one, effects on health of ionizing radiations with the following subjects ( the dose-response relationship and the estimation of carcinogen effects of ionizing radiation low doses; effect of dose rate on the induction and repair of radioinduced DNA double strand break; interest of global approach in radiation protection; molecular signature of the radioinduction in the thyroid tumors: example of radioinduced thyroid tumors after radiotherapy; incidence of child leukemia near the nuclear facilities: results of a multi sites study in France; genome instability and mutations induction after ionizing irradiation: consequences for the progeny; D.T.P.A encapsulation, an efficient strategy for the plutonium decorporation among the rat); the third one, non-ionizing radiation with the following subjects (can the exposure to a magnetic field of 100 {mu} T at 50 Hz be detected in the human physiological shiver; evaluation of the population exposure to the magnetic fields of 50 Hz: what indicators to choose; experimental study of the immunity of implantable defibrillators to the low frequencies electro-magnetic perturbations; DNA damages induced by the Ar F laser; dosimetry with a phantom in gel of human head); fourth session concerns the regulatory aspects; the fifth one presents the radiation protection and the radioactive waste management; the sixth session concerns the public and patients radiation protection; the seventh one treats the radiation protection in professional area with the following subjects ( optimization of radiation protection in the underground uranium mine of Cominak in Niger; revealing by multi parameters capillaroscopy, of micro vascular alterations of fingers among interventional radiologists; use of radioactive and chemical probes in biological research; uncertainties on doses and D.P.U.I.; monitoring of work areas. Evaluation of workers exposure towards a particular contamination; C.H.A.V.I.R., an interactive simulator for radiation protection; an ALARA engineering commune to the operating reactors; evolution of the radiological zoning and monitoring rules associated on the Cogema la Hague facility; an ambitious project for the nuclear park of EDF power plants : the purification project and its implementation for the Chinon B2 reactor - 2004); the eighth session concerns the environmental exposures and their consequences with the following presentations ( the concept of radioecological sensitivity and its interest in the risk management; phenomenal and analytical interpretation of the rain-deposit relationship used for the building of cesium 137 deposits in France consecutively to the Chernobyl accident; study of radioactivity source terms and transfer from medical origin in the purification network of the town of Toulouse; natural and artificial radioactivity in some marine species in manche. Case of polonium and plutonium alpha emitters. Synthesis of data acquired in the north Cotentin since 1990. elements of comparison; the role of local commissions of information (C.L.I.) in the follow up of release and monitoring of nuclear facilities); the ninth session concerns the dosimetry; the tenth session is divided in two parts radiation protection in accidental situations and radiation protection in post accidental situations with their respective presentations as follow ( evaluation of the dispersion of an aero contaminant in a ventilated area in field near an accidental source of emissions; study of the containment efficiency by gloveboxes in functioning accidental situations; the radiation protection and health; study by R.P.E. of the response of different materials in mixed field ( gamma, neutrons), application to the dosimetry reconstruction of an accident; nuclear or radiological events: organisation of medical intervention; and rehabilitation of life conditions in the contaminated territories: the contribution of radiation protection; management of post accidental situations: lessons from crisis exercises of Pierrelatte and Belleville; an example of participative approach: elaboration of a practical guide in the frame of an European project S.A.G.E.; school exchange between the secondary school Bois d Amour of Poitiers and the schools Olmany and Terebejov of the Stolyn district in Belarus). (N.C.)

71

Activation of the major constituents of tissue and air by a fast neutron radiation therapy beam  

The production of /sup 11/C, /sup 13/N, /sup 15/O from C, N, O, and of /sup 39/Cl and /sup 41/Ar from Ar by a p(66)Be(49) clinical neutron therapy beam has been measured. The results of these measurements were used to estimate the production of other radionuclides, then to estimate airborne radioactivity in a typical neutron therapy room and radioactivity induced in body tissues during treatment. Only under special circumstances would airborne radioactivity necessitate a waiting period before entering a typical treatment room. The additional dose to a treatment volume due to decay products from radioactivity induced within that volume would amount to a few thousandths of the given dose and the additional body dose outside the treated volume would be a few millionths of the given dose.

72

Effect of acute thioacetamide administration on rat brain phospholipid metabolism  

Brain phospholipid composition and the ({sup 32}P)orthophosphate incorporation into brain phospholipids of control and rats treated for 3 days with thioacetamide were studied. Brain phospholipid content, phosphatidylcholine, phosphatidylethanolamine, lysolecithin and phosphatidic acid did not show any significant change by the effect of thioacetamide. In contrast, thioacetamide induced a significant decrease in the levels of phosphatidylserine, sphingomyelin, phosphatidylinositol and diphosphatidylglycerol. After 75 minutes of intraperitoneal label injection, specific radioactivity of all the above phospholipids with the exception of phosphatidylethanolamine and phosphatidylcholine significantly increased. After 13 hours of isotope administration the specific radioactivity of almost all studied phospholipid classes was elevated, except for phosphatidic acid, the specific radioactivity of which did not change and for diphosphatidylglycerol which showed a decrease in specific radioactivity. These results suggest that under thioacetamide treatment brain phospholipids undergo metabolic transformations that may contribute to the hepatic encephalopathy induced by thioacetamide.

73

Five years of monitoring Cs-137 And Cs-134 in moss and soil samples in the campania region of Italy after the Chernobyl accident  

The Central Laboratory of The Italian Red Cross is part of the National Network for the Monitoring of the Environmental Radioactivity in Italy, coordinated by the National Environmental Agency (ANPA). The Central Laboratory took part in the national campaigns for the monitoring of the environmental gamma radioactivity in order to evaluate the deposition of artificial radioactivity on Italian territory after the Chernobyl accident. The distribution of the concentration of artificial radionuclide Cs-137 as reached, in North and Central Italy, the higher values: 2-185 kBq/m{sup 2} and 0-40 kBq/m{sup 2}. This paper presents the data of the concentration of artificial radionuclides Cs-137 and Cs-134 in mosses picked up in four different locations in the Campania Region of Italy with the help of the Department of the State Forestry Corp of S.Gregorio Matese, Vesuvio, Laviano, Piaggine from 1993 to 1998. The deposition of artificial radioactivity on the territory expected after the Chernobyl fallout was evaluated. The content of K-40 was also measured. Soil samples were also taken from the same sites. In this study Hypnum cupressiforme and Homalotecium lutescens mosses were used as bioindicators, available in all Italian ecosystems. The soil and moss samples were gathered according to a national standard procedure. These results, obtained by gamma spectrometry analyses, initially have shown values of medium concentration in mosses in the Campania Region of Cs-137 of 375 Bq/m{sup 2} and of Cs-134 of 16 Bq/m{sup 2} and K-40 of 150 Bq/m{sup 2} in line with the ones of other Italian regions. The results of the average concentrations of the Cs-137 and Cs-134 in the mosses confirm a uniform distribution of post-Chernobyl radioactivity in the regional territory, in the Department of the State Forestry Corp of Vesuvio, Laviano and Piaggine. The results of Cs-137 and Cs-134 of S.Gregorio Matese are in accordance with the previous data relative to the monitoring campaign of mosses in Italy from 1992 to 1993. Furthermore, it can be stated that whilst the values of Cs-137 remain constant, the values of Cs-134 show a decrease, due to the half-life of this radionuclide, even if measuring errors do not permit us to confirm with certainty the evidence of this phenomenon. The concentration of K-40, in all samples examined, has a constant value. This research has allowed us to investigate the possible correlation between the concentration of the Cs-137 and Cs-134 in the soil and in the mosses of the same location. (author)

74

Situation of the surveillance of radioactivity in French Polynesia in 2007. Results of the I.R.S.N. 's surveillance network; Bilan de la surveillance de la radioactivite en Polynesie francaise en 2007. Resultats du reseau de surveillance de l'IRSN  

The 543 atmospheric nuclear tests released radionuclides that have deposited themselves throughout the world. The Environmental Study and Surveillance Laboratory, 'Laboratoire d etude et de suivi de l'environnement' (L.E.S.E.) of the Institute of nuclear safety and radiation protection (I.R.S.N.), takes part, for more than 35 years, in the evaluation of the dosimetric consequences of these atmospheric depositions, especially those originating with the 41 tests realized in the territory of French polynesia from 1966 to 1974. This laboratory is established in Tahiti. The actualized dosimetric evaluation due to the foodstuff ingestion requires to collect the most representative samples of the feed ration of the Polynesians living in the 5 archipelagoes of this territory. These samples belong to the marine environment of full sea, the lagoon environment and the terrestrial environment. Certain samples of the physical environment are also taken (air, water). 355 samples collected in 2007 are measured by Hp-Ge low background gamma spectrometry in order to be able to characterize lowest possible radioactivity levels. The levels of activity of Pu isotopes and {sup 90}Sr are also given for 50 selected samples and tritium activities for 20 water samples. After a period of regular decay of radioactivity after the stop, in 1974, of the French atmospheric tests, the radiological state observed in the year 2007 is the same of that of the recent previous years, at a very low level. for example, the {sup 137}Cs rate in the polynesian air is ten times lower than the parisian rate. In fact, the residual radioactivity essentially relates to {sup 137}Cs, the only artificial radionuclide still measurable in the archipelago. In term of additional dose, this artificial and residual radioactivity is lower than 6 {mu}Sv by year. this value corresponds to less than 1% of exposure due to natural radioactivity in Polynesia (approximately 1 milli Sv). (N.C.)

75

Monitoring of radioactivity in drinking water; Control de la radiactividad en las aguas de consumo humano  

Radioactivity is a physical phenomenon whose presence in water is monitored due to its potential capability to induce deleterious effects on human health. In this article the effects that can be caused by radioactivity as well as the way in which regulations establish how to perform a monitorization of water that enables us to ascertain that the radiological quality of water is in agreement with the accepted standard of quality of life are analyzed. Finally the means available to know the content of radioactivity in water together with some clues on how to remove it from water are described. (Author) 5 refs.

76

Radioactivity-synchronized fluorescence enhancement using a radionuclide fluorescence-quenched dye.  

We demonstrate the first evidence of radioactivity-synchronized fluorescence quenching of a near-infrared light-emitting dye by a radionuclide, (64)Cu, and subsequent fluorescence enhancement upon (64)Cu decay to the daughter isotopes (64)Ni and (64)Zn. The dynamic switch from high radioactivity and low fluorescence to low radioactivity and high fluorescence is potentially useful for developing complementary multimodal imaging and detection platforms for chemical, environmental, and biomedical applications as well as for unraveling the mechanisms of metal-induced dynamic fluorescence changes. PMID:19514722

77

SPES: The INFN radioactive beam facility for nuclear physics  

The SPES project at Laboratori di Legnaro of INFN (Italy) is concentrating on the production of neutron-rich radioactive nuclei for nuclear physics experiment, by the Uranium fission at a rate of 1013 fission/s. The emphasis to neutron-rich isotopes is justified by the fact that this vast territory has been little explored. The Radioactive Ion Beam (RIB) will be produced by ISOL technique using the proton induced fission on a Direct Target of UCx.

78

Photorealism aftereffect  

This study reports a novel visual aftereffect for photorealism judgments. Participants observed image sequences where a photograph was gradually transformed into an artificial image (a painting or a sketch). Their task was to choose the image that was the category boundary between the photograph and the artificial image among the frames of each image sequence. This task was performed before and after observing photographs or artificial images for 1?min. The chosen images were less photorealistic after the observation of artificial images, suggesting an aftereffect for photorealism judgments. However, observation of photographs did not induce an aftereffect. It is known that the observation of the norms for perceptual judgments (e.g., the prototypical face for facial judgments) does not ind...

79

Generation of a synthetic memory trace.  

We investigated the effect of activating a competing, artificially generated, neural representation on encoding of contextual fear memory in mice. We used a c-fos-based transgenic approach to introduce the hM(3)D(q) DREADD receptor (designer receptor exclusively activated by designer drug) into neurons naturally activated by sensory experience. Neural activity could then be specifically and inducibly increased in the hM(3)D(q)-expressing neurons by an exogenous ligand. When an ensemble of neurons for one context (ctxA) was artificially activated during conditioning in a distinct second context (ctxB), mice formed a hybrid memory representation. Reactivation of the artificially stimulated network within the conditioning context was required for retrieval of the memory, and the memory was specific for the spatial pattern of neurons artificially activated during learning. Similar stimulation impaired recall when not part of the initial conditioning. PMID:22442487

80

Reduction of the cytotoxicity of triphenyltin chloride using cyclodextrins  

This report shows that cyclodextrins increase by up to 40% the survival of a marine nematode exposed to triphenyltin chloride. Environmental contamination by organotins has induced toxic effects such as endocrine disruption and destruction of the membrane structure of aquatic organisms. However, techniques to reduce organotin toxicity are scarce. Here, we tested ?-, ?-, and ?-cyclodextrins to reduce toxicity induced by triphenyltin chloride. We analyzed a receptor cofactor ligand assay system in vitro, parallel artificial membrane permeability assay, and the survival of Prochromadorella sp.1, one of the nematodes which is served as biomarkers for ecotoxicological assessment. The passive transport of triphenyltin chloride through the artificial membrane was suppressed about 20 and 40% by ?-...

 
 
 
 
81

Active experiments in magnetospheric physics.  

Magnetospheric physics has been and continues to be primarily an observational science, aided and guided by theory. However, increasing emphasis is being given to active experiments for the purpose of clarifying specific phenomena in the magnetospheric plasma. The earliest global scale experiments were the production of artificial radiation belts by high altitude nuclear bomb bursts in 1958-62 and the observation of their geophysical effects. Other active experiments involve the injection of ionized clouds of exotic vapors, the decay products of radioactive sources, and beams of artificially accelerated ions and electrons at selected points in the magnetosphere. The effects of such perturbations of the natural situation as well as those of very low frequency radio waves have been observed by sophisticated diagnostic instrumentation. The in situ determination of the ambient electric field point-by-point in the auroral zone is one of the most important and difficult undertakings. This paper reviews the achievements of active experiments and their future promise.

82

The transfer of natural (226Ra,?232Th, 40K) and artificial (137Cs, 90Sr) radionuclides from soil to the wood of a Scots pine (Pinus sylvestris L.)  

On the Stabatishke site near to Ignalina Nuclear Power Plant a near surface repository for low and intermediate-level short-lived radioactive waste is being constructed to store the waste which was produced during the decommissioning of the Ignalina Nuclear Power Plant. A possible spread of radionuclides from the near surface repository and the radiation level of expression are one at the most important aspects while evaluating the safety of the repository. The article examines the specific activity of artificial (137Cs, 90Sr) and natural (226Ra,?232Th, 40K) radionuclides in the soil of Stabatishke site of Ignalina NPP in pinewood; the spread of these radionuclides is determined in the system ?soil-tree?. The change of long term soil pollution with artificial radionuclides was estimated. T...

83

Fate and bioavailability of (14)C-pyrene and (14)C-lindane in sterile natural and artificial soils and the influence of aging.  

Soil organic matter is used to extrapolate the toxicity and bioavailability of organic pollutants between different soils. However, it has been shown that other factors such as microbial activity are crucial. The aim of this study was to investigate if sterilization can reduce differences in the fate and bioavailability of organic pollutants between different soils. Three natural soils with increasing total organic carbon (TOC) content were collected and three artificial soils were prepared to obtain similar TOCs. Soils were sterilized and spiked with (14)C-pyrene and (14)C-lindane. Total (14)C radioactivity, HPCD extractability, and bioaccumulation in Eisenia fetida were measured over 56 days. When compared to non-sterile soils, differences between the natural and artificial soils and the influence of soil-contaminant contact time were generally reduced in the sterile soils (especially with middle TOC). The results indicate the possibility of using sterile soils as "the worst case scenario" in soil ecotoxicity studies. PMID:22892571

84

Artificial and natural radioactivity in edible mushrooms from Sao Paulo, Brazil  

Environmental biomonitoring has demonstrated that organisms such as crustaceans, fish and mushrooms are useful to evaluate and monitor both ecosystem contamination and quality. Particularly, some mushroom species have a high capacity to retain radionuclides and some toxic elements from the soil and the air. The potential of mushrooms to accumulate radionuclides in their fruit-bodies has been well documented. However, there are no studies that determine natural and artificial radionuclide composition in edible mushrooms, in Brazil. Artificial (^1^3^7Cs) and natural radioactivity (^4^0K, ^2^2^6Ra, ^2^2^8Ra) were determined in 17 mushroom samples from 3 commercialized edible mushroom species. The edible mushrooms collected were Agaricus sp., Pleurotus sp. and Lentinula sp. species. The activi...

85

Surveillance of environmental radiation in Finland. Annual Report 2004; Ympaeristoen saeteilyvalvonta Suomessa. Vuosiraportti 2004  

The main goal of the surveillance of environmental radioactivity is to be always aware of levels of artificial radiation in the environment to which the public is exposed. Another goal is to detect all remarkable changes in levels of environmental radiation and radioactivity. Compliance with the basic safety standards laid down for protection of health of the general public against dangers arising from ionising radiation can be ensured with environmental radiation surveillance. Running of surveillance programmes on continuous basis also maintains and develops competence and readiness to respond to radiological emergencies. Surveillance of environmental radiation contains surveillance of artificial radiation and artificial radioactive elements in the environment. Natural radiation and natural radioactive elements are not associated with the surveillance programme, although the greater part of the public exposure to radiation is caused by natural radiation. Exposure to natural radiation is controlled separately if there is reason to suspect that natural radioactive elements cause unusual high exposure to the public (e.g. indoor radon and natural radionuclides in drinking water). Surveillance of environmental radioactivity in Finland is one of the official obligations of the Radiation and Nuclear Safety Authority (STUK). This obligation is based on the national and the European Communities' legislation. The Finnish radiation protection legislation appoints STUK as the national authority responsible for surveillance of environmental radioactivity, and the Euratom Treaty assumes continuous monitoring of levels of radioactivity in the air, water and soil in the Member States. In Finland, also the Finnish Meteorological Institute (FMI) and the Defence Forces are monitoring environmental radiation at their own stations. This report summarises the results of environmental radiation surveillance in 2004. The report also contains some comparisons with results from the previous years. The results are collected from monitoring programmes of STUK, FMI and the Defence Forces Research Institute of Technology. Nuclear power plant licensees are responsible for environmental surveillance in the vicinity of nuclear power plants in Finland. Those results are reported elsewhere. STUK's partners in surveillance of environmental radioactivity are collecting and delivering environmental samples for laboratory analyses, or are participating in whole-body counting. STUK would like to express its gratitude to the following institutions for the successful co-operation: Defence Forces, Finnish Meteorological Institute, Arctic Research Centre, Southeast Finland Regional Environment Centre, North Ostrobothnia Regional Environment Centre, Lapland Regional Environment Centre, Southeast Finland Frontier Guard District, Lapland Frontier Guard District, Jyvaeskylae Airport, Rescue Centre of Kotka, Water supply plants of Oulu and Turku, Valio Ltd., Health Department of Helsinki/Maria Hospital, Tampere University Central Hospital, Lapland Central Hospital, Secondary school of Helsingin yhteislyseo, Secondary school of Hatanpaeae in Tampere, and Secondary school of Korkalovaara in Rovaniemi. This report is addressed to all who are interested in environmental radioactivity in Finland. STUK delivers monitoring data also to the European Commission on regular basis, and this report is a summary of the results delivered to the Commission. The report is also available on the STUK's home pages www.stuk.fi. (orig.)

86

Surveillance of Environmental Radiation in Finland. Annual Report 2009; Ympaeristoen saeteilyvalvonta Suomessa. Vuosiraportti 2009  

The main goal of the surveillance of environmental radioactivity is to be always aware of levels of artificial radiation in the environment to which the public is exposed. Another goal is to detect all remarkable changes in levels of environmental radiation and radioactivity. Compliance with the basic safety standards laid down for protection of health of the general public against dangers arising from ionising radiation can be ensured with environmental radiation surveillance. Running of surveillance programmes on continuous basis also maintains and develops competence and readiness to ond to radiological emergencies. This report summarises the results of environmental radiation surveillance in 2009. The report also contains some comparisons with results from the previous years. Surveillance of environmental radiation contains surveillance of artificial radiation and artificial radioactive elements in the environment. Natural radiation and natural radioactive elements are not associated with the surveillance programme, although the greater part of the public exposure to radiation is caused by natural radiation. Exposure to natural radiation is controlled separately if there is reason to suspect, that natural radioactive elements cause unusual high exposure to the public (e.g. indoor radon and natural radionuclides in drinking water). Nuclear power plant licensees are responsible for environmental surveillance in the vicinity of nuclear power plants in Finland. Those results are reported elsewhere. Surveillance of environmental radioactivity in Finland is one of the official obligations of the Radiation and Nuclear Safety Authority (STUK). This obligation is based on the national and the European Communities' legislation. The Finnish radiation protection legislation appoints STUK as the national authority responsible for surveillance of environmental radioactivity, and the Euratom Treaty assumes continuous monitoring of levels of radioactivity in the air, water and soil in the Member States. In Finland, also the Finnish Meteorological Institute (FMI) and the Defence Forces are monitoring environmental radiation at their own stations. STUK's partners in surveillance of environmental radioactivity are collecting and delivering environmental samples for laboratory analyses, or are participating in whole-body counting. STUK would like to express its gratitude to the following partners for the successful co-operation: Defence Forces, Finnish Meteorological Institute, Arctic Research Centre, Southeast Finland Regional Environment Centre, North Ostrobothnia Regional Environment Centre, Lapland Regional Environment Centre, Southeast Finland Frontier Guard District, Lapland Frontier Guard District, Rescue Centre of Kotka, Water supply plants of Oulu and Turku, Valio Ltd., Health Department of Helsinki/Maria Hospital, Tampere University Central Hospital, Lapland Central Hospital, Secondary school of Helsingin yhteislyseo, Secondary school of Hatanpaeae in Tampere, and Secondary school of Korkalovaara in Rovaniemi. This report is addressed to all who are interested in environmental radioactivity in Finland. STUK delivers monitoring data also to the European Commission on regular basis, and this report is a summary of the results delivered to the Commission. (orig.)

87

Predictive Models for the Determination of Pitting Corrosion Versus Inhibitor Concentrations and Temperature for Radioactive Sludge in Carbon Steel Waste Tanks  

Statistical models have been developed to predict the occurrence of pitting corrosion in carbon steel waste storage tanks exposed to radioactive nuclear waste. The levels of nitrite concentrations necessary to inhibit pitting at various temperatures and nitrate concentrations were experimentally determined via electrochemical polarization and coupon immersion corrosion tests. Models for the pitting behavior were developed based on various statistical analyses of the experimental data. Feed-forward Artificial Neural Network (ANN) models, trained using the Back-Propagation of Error Algorithm, more accurately predicted conditions at which pitting occurred than the logistic regression models developed using the same data.

88

Neutrino oscillometry at the next generation neutrino observatory  

The large next generation liquid-scintillator detector LENA (Low Energy Neutrino Astronomy) offers an excellent opportunity for neutrino oscillometry. The characteristic spatial pattern of very low monoenergetic neutrino disappearance from artificial radioactive sources can be detected within the long length of detector. Sufficiently strong sources of more than 1 MCi activity can be produced at nuclear reactors. Oscillometry will provide a unique tool for precise determination of the mixing parameters for both active and sterile neutrinos within the broad mass region 0.01 - 2 (eV)^2. LENA can be considered as a versatile tool for a careful investigation of neutrino oscillations.

89

Radioactivity in the Surrounding of the BER in 1960; RADIOAKTIVITAT IN DER UMGEBUNG DES BER IM JAHRE 1960  

The results of measurements of Rn decay products and total fission products in air, fallout, and surface water in the surroundings of the BER during 1960 are summarized and compared with data from earlier years. The mean specific fission product activity has decreased to about 10% of the values during 1959. Similar to earlier years, the seasonal variation of artificial radioactivity, owing to the transport mechanism from stratosphere to troposphere, can be recognized. Operation of reactor and laboratories brought no detectable increase of activity and dose in the surroundings. (auth)

90

Natural and artificial radioactivity in the Svalbard glaciers  

Natural and artificial radioactivity in the snow of 10 Svalbard glaciers has been measured from 31 ice core samples, drilled between 1981 and 1993. Of these ice cores, seven exhibit the well-known level arising from the fallout of the 1961-62 atmospheric thermonuclear tests. The second level, due to the Chernobyl accident (26 April 1986), has been detected in all the studied glaciers; the maximum [sup 137]Cs fallout reaches 22 Bq kg[sup -1] and shows a high variability. The natural radioactivity, mostly due to [sup 210]Pb, shows an in-depth variation which is not governed by its half-life (22.2 years). These measurements serve many glaciological purposes: absolute dating of the snow layers; air-snow transfer and fallout studies; the determination of mean annual mass balances in the accumulation area of glaciers and their associated spatio-temporal variations. (author).

91

Neural network application for radionuclide modelling and prediction of radioactivity levels  

Existing applications of artificial neural networks in physics research and development have been analyzed as a basis for proposing new opportunities using that AI technology for data analysis in physics. A taxonomy was developed, based on an extensive literature search, for physics problems where neural network applications have been useful. Then, a particular use of neural networks was carried out to study ways to predict normal concentrations of radioactivity measured at monitoring stations in different geographic locations. The purpose of the data collection and analysis was to establish background levels that would serve as bases for detecting unusual levels of radioactivity, for example due to nuclear weapons testing, in these physical environments. Useful data sets were developed in this area and a process was discovered for modeling the background levels.

92

Surveillance of radioactivity in the atmosphere between prognosis and measurement - early alert in the Deutscher Wetterdienst; Radioaktivitaetsueberwachung der Atmosphaere zwischen Prognose und Messung - Frueherkennung im Deutschen Wetterdienst  

The Deutscher Wetterdienst (DWD) `German Meteorological Service` is legally responsible for the large-scale surveillance of radioactivity in the atmosphere. For an early alert of artificial radioactivity gamma-ray-spectrometry of aerosols is performed at selected meteorological stations of the synoptic-climatological network. Results of measurements as well as dispersion calculations are urgently required for making further decisions. The combination of measurements and forecasts combined with airborne measurements in an alert-situation is discussed. (orig.) [Deutsch] Der Deutsche Wetterdienst ist durch Gesetzesauftrag fuer die grossraeumige Ueberwachung der Umweltradioaktivitaet in der Atmosphaere verantwortlich. Mit dem Ziel, kuenstliche Radioaktivitaet fruehestmoeglich zu erfassen, wird an ausgewaehlten Messstationen des synoptisch-klimatologischen Beobachtungsnetzes des Deutschen Wetterdienstes die aerosolgebundene Radioaktivitaet rund um die Uhr gammaspektrometrisch bestimmt. Die schnelle Verfuegbarkeit von Messergebnissen und von meteorologischen Prognosen ist entscheidend fuer die Einleitung weiterer Massnahmen nach einer Alarmierung. Das Zusammenspiel zwischen Messwerterfassung im Messnetz, Flugzeugmessungen und Ausbreitungsprognosen im Uebergang vom Routine- in den Intensivbetrieb wird diskutiert. (orig.)

93

Warnings to the far future. Radioactive wastes as a communications problem. Warnungen an die ferne Zukunft. Atommuell als Kommunikationsproblem  

Inquiries were launched in the USA, in Poland, France, Hungary, Brazil, and the Federal Republic of Gemany to find semiotic solutions to problems arising from the communication of radioactive waste locations and dangers to posteriority. How can information be communicated over a period of 10000 years What has been communicated to us from the past 10000 years It seems to be sure that neither natural nor artificial barriers nor remnants (e.g. skeletons) or sources (today's communication), but only explicit messages will keep intelligent creatures from intrusion into radioactive waste depositories. Among the subjects dealt with are: Pandora's box and how to prevent its opening; mathematical coding on living sign matter; living detectors and complementary signs: ray coat, broken eye, and nuclear sirens; the three-chamber system: a way to the democratic organization of collective knowledge and conscience which can survive millennia. (orig./HSCH).

94

Rutherford, Radioactivity, and the Atomic Nucleus  

Modern atomic and nuclear physics took its start in the early part of the twentieth century, to a large extent based upon experimental investigations of radioactive phenomena. Foremost among the pioneers of the new kind of physics was Ernest Rutherford, who made fundamental contributions to the structure of matter for more than three decades and, in addition, founded important research schools in Manchester and Cambridge. This paper reviews the most important aspects of Rutherford's scientific work in the period from about 1900 to 1920, and it also refers to some of his last experiments of the 1930s. The emphasis is on his theory of radioactive disintegration (1902), the discovery of the atomic nucleus (1911), and the first artificially produced element transformation (1919). Following the transmutation experiments, Rutherford developed elaborate models of the atomic nucleus, but these turned out to be unsuccessful. Other subjects could be included, but the three mentioned are undoubtedly those of the greates...

95

Radioactivity monitoring status in French Polynesia in 2008. Results from IRSN's monitoring network; Bilan de la surveillance de la radioactivite en Polynesie francaise en 2008. Resultats du reseau de surveillance de l'IRSN  

Radiological monitoring of the French environment is one of IRSN's permanent tasks as part of public policy on nuclear safety and radiological protection. It is helping to guarantee the best possible protection of the population. The task addresses two objectives: - To monitor the levels of artificial radioactivity in all sectors of the environment and in major foodstuffs; - To estimate the exposure of the Polynesian population to this artificial radioactivity. The IRSN has monitored radioactivity levels in French Polynesia, excluding the Mururoa and Fangataufa nuclear experimentation centres, since 1962. This task is realized by the IRSN's Environmental Study and Monitoring Laboratory located in Tahiti (Vairao) This monitoring was instigated at the time when atmospheric nuclear weapons testing was being performed by the major powers (the United States, the Soviet Union, the United Kingdom, France and China), causing fallout of artificial radionuclides, over several years, on a planetary scale. In French Polynesia, the IRSN is most particularly interested in fallout resulting from the 41 tests carried out by France in this region of the globe between 1966 and 1974, and in its consequent effects on the population. Today, just as in metropolitan France, the IRSN carries out monitoring as part of its mission to constantly monitor radiological protection factors. The monitoring takes place on seven islands (Tahiti, Maupiti, Hao, Rangiroa, Hiva Oa, Mangareva and Tubuai) representing the five archipelagoes and consists of taking monthly samples of various kinds from the different environmental compartments (air, water, soil, food...) with which the population may be in contact. For more than 40 years, the IRSN takes part in the evaluation of the dosimetric consequences of these atmospheric depositions in French Polynesia. This laboratory is established in Tahiti. The ingestion component of this dosimetric evaluation requires to collect the most representative samples of the 'feed ration' of the Polynesians living in the 5 archipelagoes of this territory. These samples belong to the marine environment of full sea, the 'lagoon' environment and the terrestrial environment. Some samples of the physical environment are also taken (air, water). The 334 samples collected in 2008 were measured by Hp-Ge low background gamma spectrometry in order to be able to characterize lowest possible radioactivity levels. The levels of activity of Pu isotopes and {sup 90}Sr have also been determined for 54 selected samples and tritium activities for 20 water samples. During the year 2008 results fall under the continuity of a regular reduction of the levels of radioactivity since the stop, in 1974, of the French atmospheric tests. This residual radioactivity relates to primarily the {sup 137}Cs. In term of additional dose, this artificial and residual radioactivity is lower than 5 {mu}Sv.y{sup -1} (5 micro-Sieverts per year). This value corresponds to less than 1 % of exposure due to natural radioactivity in Polynesia (approximately 1000 {mu}Sv.y{sup -1}). (authors)

96

Use of aquatic mosses for monitoring artificial radionuclides downstream of the nuclear power plant of Bugey (River Rhone, France)  

The detection of radionuclides in water, downstream of nuclear installations located on river banks, is often very difficult notably because of their low concentrations. Thus the use of biological indicators is an interesting process to detect radioactive contamination of an aquatic ecosystem. From 1986 to 1990, artificial radionuclides were measured in freshwater mosses sampled downstream of the nuclear power station of Bugey. These field data on the whole, have shown a comparatively good qualitative and quantitative relationship between radioactive composition of liquid waste and radionuclides detected in mosses. In other respects, the results showed up a relatively clear hierarchical structure in the affinity of the different radionuclides for the mosses. To specify these relations, mesh bags containing allochtonous mosses were immersed at four stations downstream of the power plant and regularly sampled during a 10-h waste discharge period. (author).

97

The implications of particle energy and acidic media on gross alpha and gross beta determination using liquid scintillation  

The interaction of humans with radioactivity present in the environment from natural and artificial sources necessitates an evaluation of its risk on human health. Gross alpha and gross beta activities can provide a rapid evaluation of the radioactive content of a sample and can be simultaneously determined by using liquid scintillation counters. However, calibration of the liquid scintillation counter is required and is affected by many factors, such as particle energy and the acidity of the media. This study investigates what effect the particle energy used for calibration has on misclassification and how to account for this misclassification in routine measurements. The variability in measurement produced by the final pH, as well as any acids used in sample treatment, was also studied. ...

98

A Physio-anthropological Approach in Evaluation of Human Adaptability to Living Environment: In the Case of Artificial Light Environment  

Attention has been focused on human adaptability to human-adopted artificially modern and comfortable environments which may not always match the adaptability by the physiological state of humans. This discrepancy was found to induce a slight tension in the human body on evaluation with a physio-anthropological approach. Although a standard methodological approach has yet to be established, the present study attempted to evaluate human adaptability to artificial light environment, based on evaluations from three major possible perspectives: a) central nervous system, b) autonomic nervous system and c) biological rhythm. In order to detect the slight tension, human volunteers were exposed to an artificial light environment, and the appropriate physiological parameters were then examined from photic signal pathways in a brain. The findings revealed that a higher color temperature of fluorescent lamps induced a slight tension, although many other factors remained to be elucidated.   

99

Effect of Proximity and Dimension of Two Artificial Pitting Holes on the Fatigue Endurance of Aluminum Alloy AISI 6061-T6 Under Rotating Bending Fatigue Tests  

This work deals with the study of the two artificial pitting holes effects, caused by their dimensions and proximity, on the fatigue endurance of aluminum alloy AISI 6061-T6 under rotating bending fatigue tests. Stress concentration induced by artificial pitting holes is analyzed and correlated with the experimental fatigue life. It is found that the stress concentration increases exponentially when the two pitting holes approach, and this induces an important reduction in the fatigue life. Concerning the diameter variation of one pitting in regard to the second, no important influence was observed on fatigue life for a given separation between them; this implies that the separation between the two artificial pitting holes and the associated stress concentration is the principal parameter on the fatigue life under these conditions. Finally, results are discussed and conclusions are presented involving the fatigue life, proximity, and dimension of pitting holes, stress concentration factor, and fracture surfaces where the failure origin is identified.

100

A Sticky Affair: Resin Collection by Bornean Stingless Bees  

ABSTRACT Plant resins are used by stingless bees for nest construction and maintenance. To reveal factors that influence the bees' decision about where and when to collect resin, resin collection was studied in ten stingless bee species (Apidae, Meliponini) collecting resin at natural and artificially induced wounds of nine tree species in Borneo. Artificially induced wounds were found by bees within 1-2 d. The number of foragers at artificial wounds increased during the subsequent 5 d until resin secretion stopped or the resin hardened. At natural resin wounds, species identity and number of foragers remained constant during the observation period. Bees collected resin from some trees and ignored others. Agathis borneensis (Araucariaceae) was the most attractive resin source. The bees' vi...

 
 
 
 
101

Works of chemists researching radioactivity involved in two accidents this fall; Houshano wo kenkyu suru kagakusha no kataraki. Honshu no 2 jiken ni saishite  

Two accidents happened in September 1999 (meteorite dropping accident and JCO criticality accident) are linked to each other at a common point concerning radioactivity, and chemists specialized in radioactivity have been executing active researches. In this paper, a focus of discussion is put on the measurement of radioactivity induced by neutrons due to cosmic rays or criticality. Researches executed actively by the chemists during several weeks for calculating neutron fluxes around the spot of the criticality accident and estimating the meteorite matrix on the basis of nuclear reaction in outer space under absolute time restriction of radioactive half life. In the meteorite dropping falling accident, a stone fell through the roof of the second floor of a private house in Kobe, and this stone was proved to be a meteorite on the basis of a non-destructive {gamma} ray spectrum measurement carried out by the Low Level Radioactivity Experiment Facility of Science Department of Kanazawa University. Detections of Mg-28 with a radioactive half life of 21 hours and Ni-57 with a radioactive half life of 1.45 days were succeeded for the first time in the world owing to an extremely short time from finding information on the internet till carrying out the measurements. (NEDO)

102

Measurement of performances of aerosol type radioactive contamination monitors  

The EPICEA laboratory (Laboratoire d'Essais Physiques des Instruments de Mesure de la Contamination de l'Eau de de l'Air), which belongs to the Institut de Protection et de Surete Nucleaire (IPSN), was created to carry out type tests on atmospheric contamination monitors under the conditions recommended by the International Electrotechnical Commission (IEC). These tests are carried out at the request of users, scientific or industrial manufacturers, either French or foreign, to define the performance of a given aerosol radioactive contamination monitor in order to obtain type approval for the monitor by the IPSN Centre Technique d'Homologation de l'Instrumentation de Radioprotection (CTHIR). Tests can also be used for defining prototypes manufactured by the industry. There are two types of tests: (1) Static tests are performed with solid standard radioactive sources. Six different tests are used to verify the performances of the monitors and to measure their detection efficiency for solid sources. (2) Dynamic tests are performed on the ICARE bench. This bench, continuously generating natural and artificial radioactive aerosols, calibrated for size and activity, enables the true performances of the radioactive aerosols monitors to be defined under normal operating conditions. The true measurement efficiency is obtained by sampling and measuring, in real time, the activity of aerosols labelled with {sup 239}Pu and/or {sup 137}Cs. The influence of the natural activity upon the artificial activity measurement channels is determined by aerosols bearing radon decay products whose concentration and attached fraction can be adjusted. Knowledge of the factor of influence of the natural activity and the type of treatment (algorithm) used on this monitor makes it possible to calculate the monitor detection threshold under normal operating conditions. The dynamic test procedures described in this document have been adopted as an international standard by the IEC in 1995. (author)

103

Effects of Intraplantar Morphine in the Mouse Formalin Test  

We studied the effects of intraplantar morphine in the formalin test in mice.Intraplantarly administered morphine(30?300?g)induced analgesic effects at lower doses than intraperitoneally administered morphine.Following the administration of [3H]morphine, the % of radioactivity present in brain was the same by either route.In contrast, higher radioactivity values appeared in the injected paw in those mice intraplantarly injected.Since local morphine induces analgesia at doses lower than the intraperitoneally administered drug, especially in the second phase of the test, and the access to brain is undistinguishable, we propose that local morphine enhances central opiate analgesia in the formalin test in mice.   

104

Consequences of the Chernobyl accident for people and the environment; Les consequences de Tchernobyl pour l'homme et l'environnement  

This report recalls the accident scenario, discusses the dispersion of the radioactive plume, comments the contamination at the vicinity of the power station, discusses and comments data related to radioactive deposits in Europe and in France, comments available information regarding radioactive fallouts in Belarus, Ukraine and Russia (models have been used to assess radioactive deposits). It addresses the issue of food product contamination in these three countries (impact on farm products, on water streams and on forests), but also in France. It comments the health impacts, more particularly on the people who intervened on the site, but also on people who received medium doses. Thyroid cancer data are discussed for the three mainly concerned countries. Other pathologies and non-cancerous effects are also discussed. The mortality induced by the accident is commented. Effects in France are evoked as well as social and economic consequences in Ukraine, Belarus and Russia. The document provides several links to other documents for further and more detailed information

105

Study of particle size distribution and formation mechanism of radioactive aerosols generated in high-energy neutron fields  

The size distributions of sup 3 sup 8 Cl, sup 3 sup 9 Cl, sup 8 sup 2 Br and sup 8 sup 4 Br aerosols generated by irradiations of argon and krypton gases containing di-octyl phthalate (DOP) aerosols with 45 MeV and 65 MeV quasi-monoenergetic neutrons were measured in order to study the formation mechanism of radioactive particles in high energy radiation fields. The effects of the size distribution of the radioactive aerosols on the size of the added DOP aerosols, the energy of the neutrons and the kinds of nuclides were studied. The observed size distributions of the radioactive particles were explained by attachment of the radioactive atoms generated by the neutron-induced reactions to the DOP aerosols. (author)

106

Seismicity-induced groundwater level changes in boreholes around Mizunami Underground Research Laboratory (MIU), Japan: Effect of the 2011 off the Pacific coast of Tohoku Earthquake  

For improving the scientific basis for geological disposal of high-level radioactive waste, multidisciplinary researches are approached in the MIU, in which two vertical shafts are excavated in the crystalline rock mass. Groundwater levels are continuously logged in multiple boreholes, for understanding the regional groundwater flow around the MIU site. Soon after the 2011 off the Pacific coast of Tohoku Earthquake, groundwater level changes were observed in the almost boreholes. All boreholes arranged away from the MIU (approximately 1 to 5 km) showed drawdown ranging from 1 to 5 m. Several studies (e.g. Wang, 1997, JGR; Ge and Stover, 2000, JGR; Hamiel et al., 2005, EPSL) suggest that coseismic changes of groundwater level correspond to static volumetric strain changes induced by earthquakes, i.e., drawdown/elevation of groundwater level is reflected by crustal dilatation/constriction. We calculated volumetric strain changes due to the Tohoku earthquake based on the previously-reported fault models (slip models estimated by teleseismic source inversion; Yagi and Nishimura, Univ. of Tsukuba; Poiata et al., ERI, Univ. of Tokyo). We determined crustal deformation and stress change using the program Coulomb 3.0 (Lin and Stein, 2004, JGR; Toda et al., 2005, JGR). The calculation outputs approximately 2.3E-7 strain of dilatation around the MIU. Thus the drawdown observed in the boreholes arranged away from the MIU is consistent with the volumetric strain changes associated with the Tohoku earthquake. In contrast, groundwater levels were elevated up to 15 m in the boreholes localized in the vicinity of the MIU (within 600 m). These boreholes had shown successive drawdown since the shaft excavations started in the MIU, while voluminous sump water had been released successively from the shafts. Soon after the Tohoku earthquake, volume of the sump water increased approximately ten percent. Irregular elevation of water level soon after an earthquake like the case of the MIU has been reported in other excavation sites where successive drawdown is observed (e.g. Kitano and Tamai, Geoline2005, Lyon). Dilatation caused by an earthquake could induce fracture aperture opening and subsequent permeability increase, which could cause the anomalous increase of the sump water and the elevation of the groundwater level within the MIU site, as a temporal recovery of artificial drawdowned groundwater level.

107

NATURAL OCCURRENCE OF INDUCED OR ARTIFICIAL FLAGELLAR ANTIGENS IN SALMONELLA NEWPORT  

Douglas, G. W. (Communicable Disease Center, Atlanta, Ga.), Alma C. McWhorter, and P. R. Edwards. Natural occurrence of induced or artificial flagellar antigens in Salmonella newport. J. Bacteriol. 83:348–350. 1962.—Two epidemiologically related cultures of Salmonella newport, which possessed natura...

108

Electroporation: an arsenal of application  

Electroporation is a way to induce nanometersized membrane pore for exogenous substances delivery into cytoplasm using an artificial electric field. Now it was widely used for molecules transfer especially in molecular experiments and genetic aspects. In recent years, modern electroporation on the e...

109

RNAi-mediated inhibition of HIV-1 by targeting partially complementary viral sequences  

Potent antiviral RNAi can be induced by intracellular expression of short hairpin RNAs (shRNAs) and artificial microRNAs (miRNAs). Expression of shRNA and miRNA results in target mRNA degradation (perfect base pairing) or translational repression (partial base pairing). Although efficient inhibition...

110

Biotechnology of Accelerated Breeding and Improvement of Cotton Varieties  

An important factor promoting variation in natural populations is the constant changes in the micro-environment surrounding the population. This variation in the micro-environment is due to both naturally occurring and artificially induced environmental factors. These same factors influence intentio...

111

Four new Ceratocystis spp. associated with wounds on Eucalyptus, Schizolobium and Terminalia trees in Ecuador  

Species of Ceratocystis commonly infect wounds on trees. In this study, artificially induced wounds were made on the stems of Eucalyptus, Schizolobium and Terminalia trees in Ecuadorian lowland forests, in an effort to determine the presence of Ceratocystis spp. in that environment. Species belongin...

112

31P NMR characterization of terminal phosphates induced on DNA by the artificial nuclease 'Mn-TMPyP/KHSO5' in comparison with DNases I and II.  

Phosphorus-31 NMR has been applied to the characterization of terminal phosphates on fragments of calf thymus DNA induced by three different nuclease systems: DNase I, DNase II and the artificial nuclease 'Mn-TMPyP/KHSO5'. In this last case, the oxidative damage to deoxyribose leads to two monophosp...

113

Brave new fruits. [Mutation breeding in fruit trees  

Gamma rays are being used for artificially inducing mutations in deciduous fruits, so that improvements in characteristics and quality can be developed and new fruit cultivars sent out to compete on international markets. Progress in this field of research at Stellenbosch is described.

114

QUICR-learning for Multi-Agent Coordination  

dressed with temporal difference methods such as Q-learning. The second credit assignment problem is ... Copyright cO 2006, American Association for Artificial Intelli- ... the foraging domain, specific rules induce good division of labor (Jones .... mining the reward grows linearly with the number of agents, while the number ...

115

Mode of action of the staphylococcinlike peptide Pep 5: voltage-dependent depolarization of bacterial and artificial membranes.  

The cationic staphylococcinlike peptide Pep 5 is shown to depolarize bacterial and planar lipid membranes in a voltage-dependent manner. An artificial valinomycin-induced potassium diffusion potential across the cytoplasmic membrane of Staphylococcus cohnii 22 was sufficient to promote Pep 5 action....

116

N68: 163 8 9  

of waves in arteries and veins, an extensive parametric study has been carried out. A linearized .... Artificial heart sounds of controlled frequency have been induced by placing the ..... the femoral arteries. By placing one .... to the core of a solenoid driven harmonically by an electronic oscillator via a high- ... More advanced ...

117

The visual centring response in desert ants, Cataglyphis fortis.  

When negotiating their way through cluttered environments, desert ants, Cataglyphis fortis, tend to run along the midlines of the alleys formed by adjacent low shrubs. This 'centring response' was investigated by inducing foraging ants to walk through artificial channels. The sidewalls of the channe...

118

Paradoxical Effects of Short Term Triiodothyronine administration to hypothyroid broiler chickens.  

The purpose of these experiments were to determine possible relationships among certain indices of lipid metabolism and specific gene expression in chickens fed methimazole to induce a kind of artificial hypothyroidism. In both experiments, male, broiler chickens growing from 14 to 28 days of age we...

119

Polypyrrole–metal Coil Composites as Fibrous Artificial Muscles  

A polypyrrole deposited electrochemically on tungsten coil showed 11.6% strain and 0.20 N force induced electrochemically. The W coil significantly reduced iR drop of the PPy, resulting in improving performance of the actuator. The fibrelike structure was suitable for applications of artificial muscles.   

120

SigM-Responsive Genes of Bacillus subtilis and Their Promoters?  

Promoters of nine Bacillus subtilis genes (bcrC, yacK, ydaH, yfnI, yjbD, ypbG, ypuA, yraA, and ysxA), all responsive to artificially induced increases in the stress-responsive extracytoplasmic function sigma factor, SigM, were mapped by rapid amplification of cDNA ends-PCR. The resulting promoter co...

 
 
 
 
121

Influence of Biosurfactants from Probiotic Bacteria on Formation of Biofilms on Voice Prostheses  

Biofilms were grown on preconditioned voice prostheses with biosurfactants obtained from probiotic bacteria Lactococcus lactis 53 and Streptococcus thermophilus A in an artificial throat model. Both biosurfactants greatly reduced microbial numbers on prostheses and also induced a decrease in the air...

122

Analysis of Digital POSS-II Catalogs Using Hierarchical Unsupervised Learning Algorithms  

We apply techniques from the field of machine learning/ artificial intelligence to the problem of inducing meaningful structure from astronomical data. \\cobweb//95 is a concept formation system that accepts objects incrementally and organizes them into a classification tree. The system has been successfully applied to cluster sky objects which were derived from the SKICAT data cataloging/analysis system.

123

Using Biotechnology to Accelerate Breeding of Improved Cotton Varieties  

An important factor promoting variation in natural populations is the constant changes in the micro-environment surrounding the population. This variation in the micro-environment is due to both naturally occurring and artificially induced environmental factors. These same factors influence intentio...

124

Coherent control of microwave pulse storage in superconducting circuits  

Coherent pulse control for quantum memory is viable in the optical domain but nascent in microwave quantum circuits. We show how to realize coherent storage and on-demand pulse retrieval entirely within a superconducting circuit by exploiting and extending existing electromagnetically induced transparency technology in superconducting quantum circuits. Our scheme employs a linear array of superconducting artificial atoms coupled to a microwave transmission line.

125

Ginkgo Biloba Extract EGB761 Protects against Aging-Associated Diastolic Dysfunction in Cardiomyocytes of D-Galactose-Induced Aging Rat  

The aim of the present study was to make use of the artificially induced aging model cardiomyocytes to further investigate potential anti-aging-associated cellular diastolic dysfunction effects of EGB761 and explore underlying molecular mechanisms. Cultured rat primary cardiomyocytes were treated wi...

126

Bistability of the naturally induced lactose utilization system of Escherichia coli  

In the absence of the preferred sugar glucose, lactose utilization machinery in the bacterium E. coli is activated. The genetic circuit responsible for this response, lac operon, has been observed to exhibit bistability when induced by an artificial inducer, TMG. Here we investigate conditions under which bistability might be observed in response to lactose. The aim of our study is to establish whether the natural system exhibits bistability, as is often assumed despite the lack of experimental support.

127

No evidence found for induction of dominant lethal mutations and heritable translocations in male mice by calcium cyclamate  

Calcium cyclamate, an artificial sweetener, was studied for its effectiveness in inducing transmissible chromosomal aberrations in germ cells of male mice. Both the dominant-lethal and the heritable translocation tests were carried out following daily treatment (on weekdays) of males by oral intubation with the maximum tolerated dose for 6 weeks. Calcium cyclamate is negative in both tests; therefore, there is no evidence of induced chromosome breakage and exchange.

128

IRACM : A code system to calculate induced radioactivity produced by ions and neutrons  

It is essential to estimate of radioactivity induced in accelerator components and samples bombarded by energetic ion beams and the secondary neutrons of high-energy accelerator facilities in order to reduce the amount of radioactive wastes and to minimize radiation exposure to personnel. A computer code system IRACM has been developed to estimate product nuclides and induced radioactivity in various radiation environments of accelerator facilities. Nuclide transmutation with incident particles of neutron, proton, deuteron, alpha, {sup 12}C, {sup 14}N, {sup 16}O, {sup 20}Ne and {sup 40}Ar can be computed for arbitrary multi-layer target system in a one-dimensional geometry. The code system consists of calculation modules and libraries including activation cross sections, decay data and photon emission data. The system can be executed in both FACOM-M780 mainframe and DEC workstations. (author)

129

Efficient Monte Carlo simulation of delayed activation analysis experiments  

An approach is described for efficiently modelling delayed activation analysis experiments, where radioactivity is induced in a sample through irradiation with neutrons or gamma-rays and subsequently measured by a separate detection system. The continuous single-history method is used, in which a single computer code tracks both the initial irradiation quantum and the decay products of any induced radioactive nuclei in a single event using Monte Carlo methods. Key aspects of the approach include the forcing of both the irradiation and decay processes to improve efficiency and the ability to simulate complex radioactive decays producing multiple, coincident decay products. The method has been implemented in the general-purpose EGSnrc code. A comparison with experimental results for the phot...

130

Nationwide survey on the operational status of medical compact cyclotrons in Japan  

The management of induced radioactivity of the cyclotron itself and structures is an important issue in decommissioning of medical compact cyclotrons. To obtain basic data on the actual operational conditions of cyclotrons, we performed nationwide survey. The actual beam current was about half of the maximum beam current indicated in the official permits for cyclotron operation. The actual operating time was about 10% of the maximum operating time indicated in the official permits. The average daily radioactive-nuclide (18F) production was only 10% of the allowed maximum quantity. From these results, it became clear that the induced radioactivity of a cyclotron and its concrete structures based on the maximum beam current and the maximum operating time may be overestimated. These basic dat...

131

Evaluation of the radioactivity in concrete from accelerator facilities  

For evaluation of radioactivity induced in the concrete samples from accelerator facilities, the residual radioactivity in concrete sample, collected from seven accelerator facilities, was determined by ?-ray spectrometry. The tritium was extracted by the heating method using an IR furnace, and measured with a liquid scintillation counter. It was found that the major radioisotopes activated mainly by neutrons in the concrete samples were 152Eu, 60Co, 134Cs and 3H. The concentrations of radioactivities induced by thermal neutron capture are the highest at a depth of 10 cm in the concrete wall. The correlation between tritium, 60Co and 152Eu activity was investigated by measuring many concrete samples for seven accelerator facilities. The results indicate that their activities are strongly c...

132

Parkinson's disease identification through optimum-path forest.  

Artificial intelligence techniques have been extensively used for the identification of several disorders related with the voice signal analysis, such as Parkinson's disease (PD). However, some of these techniques flaw by assuming some separability in the original feature space or even so in the one induced by a kernel mapping. In this paper we propose the PD automatic recognition by means of Optimum-Path Forest (OPF), which is a new recently developed pattern recognition technique that does not assume any shape/separability of the classes/feature space. The experiments showed that OPF outperformed Support Vector Machines, Artificial Neural Networks and other commonly used supervised classification techniques for PD identification. PMID:21097130

133

Allium Test for Assessing Chromotoxic Effects of Artificial Yellow Dye  

Chromotoxic effects of artificial yellow dye, used by grocer for colouring yellow pulses has been studied on root mitosis of Allium cepa. Root tips were treated with 3 concentrations (100, 200, 400 ppm) for 1, 2, 4 h. The dye inhibited cell division and there was decline in the mitotic index with the increase in dye concentration and duration of treatment. Dye induced a wide range of mitotic abnormalities like changed nuclear morphology, nuclear death, perforation, micronuclei, fragment, bridges, nuclear bursting, giant cell, polyploidy etc. Use of such artificial dye for colouring the consumables warrants serious consideration.   

134

Neural Mechanisms of Short-term Plasticity in the Human Visual System  

Following circumscribed retinal damage, extensive reorganization of topographically organized visual cortical areas has been demonstrated in several species of mammals (including humans). Although reorganization is often studied over extended time scales, neural response properties change within seconds of retinal deafferentation. Understanding the mechanisms underlying these short-term effects is essential for developing a complete picture of representational plasticity. One approach to the study of short-term plasticity has been to use an artificial scotoma, a stimulus-induced analog of a retinal scotoma, as a model. Here, we use event-related potentials in an artificial scotoma paradigm to examine 2 aspects of short-term plasticity in the human visual system. First, we investigated the ...

135

Novel Diet for Short-Neck Clam by Using Porphyra Spheroplasts  

Spheroplasts (PS) were prepared by degradation of the cell wall of a low quality laver Porphyra yezoensis with enzymes, and were used for a new artificial diet for short-neck clams Ruditapes philippinarum. Short-neck clams in aquarium were given the PS diet or condensed natural diatom Chaetoceros gracilis for 45 days. The PS diet induced a superior nutritional effect on the growth performance and carcass composition of short-neck clams as good as the diatom. As results, PS was found to be a useful ingredient of new artificial diet for short-neck clam that can be substituted for live microalgae.   

136

Influence of the thermal route on the peak-aged microstructures in an Al-Mg-Si aluminum alloy  

The influence of the thermal route on the peak-aged microstructures in an Al-Mg-Si aluminum alloy was investigated by atom probe tomography and transmission electron microscopy. Direct artificial aging induced a monomodal size distribution of @b''-precipitates, while for artificial aging after natural pre-aging a bimodal size distribution was found. This difference can be explained by the impact of lattice defects on the @b''-nucleation. @b'' is supposed to contain Al and exhibits a high Mg/Si ratio in the studied alloy.

137

Drying of deciduous trees  

The various deciduous trees that are economically important in France are presented together with their physical and mechanical properties; the sawing market structure is then analyzed which gives evidence for the many advantages induced by drying. Natural drying is first described followed by the various artificial drying methods. Performances and costs of the various artificial drying methods and dryers are presented together with their application domains and energy source compatibility. A method for selection and technico-economical feasibility studies is proposed. Examples in industry are given.

138

Preparation and characterization of a VEGF-Fc fusion protein matrix for enhancing HUVEC growth  

To enhance vascularization of hydrophobic implants in vivo, a VEGF-Fc fusion protein consisting of vascular endothelial growth factor (VEGF) fused to the immunoglobulin G Fc domain was prepared as an artificial extracellular matrix (ECM). VEGF-Fc was stably immobilized on a polystyrene plate due to the hydrophobicity of the Fc domain, and significantly enhanced the adhesion of human umbilical vein endothelial cells (HUVECs). Additionally, the use of VEGF-Fc as an ECM markedly promoted the proliferation of HUVECs longer than 72 h and induced the reorganization of actin filaments into larger stress fibers within these cells. The VEGF-Fc fusion protein may be a promising artificial ECM for enhancing endothelial cell growth.

139

Evaluation of Terrorist Interest in Radioactive Wastes  

Since September 11, 2001, intelligence gathered from Al Qaeda training camps in Afghanistan, and the ensuing terrorist activities, indicates nuclear material security concerns are valid. This paper reviews available information on sealed radioactive sources thought to be of interest to terrorists, and then examines typical wastes generated during environmental management activities to compare their comparative 'attractiveness' for terrorist diversion. Sealed radioactive sources have been evaluated in numerous studies to assess their security and attractiveness for use as a terrorist weapon. The studies conclude that tens of thousands of curies in sealed radioactive sources are available for potential use in a terrorist attack. This risk is mitigated by international efforts to find lost and abandoned sources and bring them under adequate security. However, radioactive waste has not received the same level of scrutiny to ensure security. This paper summarizes the activity and nature of radioactive sources potentially available to international terrorists. The paper then estimates radiation doses from use of radioactive sources as well as typical environmental restoration or decontamination and decommissioning wastes in a radioactive dispersal device (RDD) attack. These calculated doses indicate that radioactive wastes are, as expected, much less of a health risk than radioactive sources. The difference in radiation doses from wastes used in an RDD are four to nine orders of magnitude less than from sealed sources. We then review the International Atomic Energy Agency (IAEA) definition of 'dangerous source' in an adjusted comparison to common radioactive waste shipments generated in environmental management activities. The highest waste dispersion was found to meet only category 1-3.2 of the five step IAEA scale. A category '3' source by the IAEA standard 'is extremely unlikely, to cause injury to a person in the immediate vicinity'. The obvious conclusion of the analysis is that environmental management generated radioactive wastes have substantially less impact than radioactive sources if dispersed by terrorist-induced explosion or fire. From a health standpoint, the impact is very small. However, there is no basis to conclude that wastes are totally unattractive for use in a disruptive or economic damage event. Waste managers should be cognizant of this potential and take measures to ensure security of stored waste and waste shipments. (authors)

140

Maximizing accuracy in half-life measurements, by minimizing error, with application to Bi-212 and Po-218  

Radon and short-lived progeny existing in all three primordial series, namely uranium, thorium and actinium, are of most significance for human exposure, since their inhalation is implicated in bronchogenic carcinoma. Because the dosimetric calculations utilize half-life, it is important to known this parameter with the maximum possible accuracy. The half-lives of Po-218 and Bi-212, radon-222 and radon-220 progeny, were measured as 3.078 {plus minus} 0.01 min and 59.81 {plus minus} 0.23 min respectively. Experimental data collected by {alpha}-counting included background from both the counter and the intrinsic radioactivity. A comparison of all mathematical methods presently employed in the analysis of experimental radioactivity decay is presented. Artificial data corresponding to three different nuclides, different total experimental duration, and different counting time intervals were generated. Testing these data showed that the WLSQ with the correct weighting factor gives the higher accuracy and precision. Without spectrometry, it is impossible to measure the quantity or half-life of Po-218 unless correction is made for the Po-214 daughter. For the measurement of Po-218, samples containing the short-lived radon-222 daughters were collected electrostatically. A method used to estimate the initial radon daughters concentration in air based on regression analysis is proposed. The comparison of this with the well known Thomas method using artificial data showed that the regression analysis method leads to more accurate results.

 
 
 
 
141

Genotoxic and reprotoxic effects of tritium and external gamma irradiation on aquatic animals.  

Aquatic ecosystems are chronically exposed to natural radioactivity or to artificial radionuclides released by human activities (e.g., nuclear medicine and biology,nuclear industry, military applications). Should the nuclear industry expand in the future, radioactive environmental releases, under normal operating conditions or accidental ones, are expected to increase, which raises public concerns about possible consequences on the environment and human health. Radionuclide exposures may drive macromolecule alterations, and among macromolecules DNA is the major target for ionizing radiations. DNA damage, if not correctly repaired, may induce mutations, teratogenesis, and reproductive effects. As such, damage at the molecular level may have consequences at the population level. In this review, we present an overview of the literature dealing with the effects of radionuclides on DNA, development, and reproduction of aquatic organisms. The review focuses on the main radionuclides that are released by nuclear power plants under normal operating conditions, ? emitters and tritium. Additionally, we fitted nonlinear curves to the dose-response data provided in the reviewed publications and manuscripts, and thus obtained endpoints commonly associated with ecotoxicological studies, such as the EDR(10). These were then used as a common metric for comparing the values and data published in the literature.The effects of tritium on aquatic organisms were reviewed for dose rates that ranged from 29 nGy/day to 29 Gy/day. Although beta emission from tritium decay presents a rather special risk of damage to DNA, genotoxicity-induced by tritium has been scarcely studied. Most of the effects studied have related to reproduction and development. Species sensitivity and the form of tritium present are important factors that drive the ecotoxicity of tritium. We have concluded from this review that invertebrates are more sensitive to the effects of tritium than are vertebrates.Because several calculated EDR10 values are ten times lower than background levels of ? irradiation the results of some studies either markedly call into question the adequacy of the benchmark value of 0.24 mGy/day for aquatic ecosystems that was recommended by Garnier-Laplace et al. (2006), or the dose rate estimates made in the original research, from which our EDR(10) values were derived, were under estimated, or were inadequate. For ? irradiation, the effects of several different dose rates on aquatic organisms were reviewed, and these ranged from 1 mGy/day to 18 Gy/day. DNA damage from exposure to y irradiation was studied more often than for tritium, but the major part of the literature addressed effects on reproduction and development. These data sets support the benchmark value of 0.24 mGy/day, which is recommended to protect aquatic ecosystems. RBEs, that describe the relative effectiveness of different radiation types to produce the same biological effect, were calculated using the available datasets. These RBE values ranged from 0.06 to 14.9, depending on the biological effect studied, and they had a mean of 3.1 ± 3.7 (standard deviation). This value is similar to the RBE factors of 2-3 recommended by international organizations responsible for providing guidance on radiation safety. Many knowledge gaps remain relative to the biological effects produced from exposure to tritium and y emitters. Among these are: Dose calculations: this review highlights several EDR(10) values that are below the normal range of background radiation. One explanation for this result is that dose rates were underestimated from uncertainties linked to the heterogenous distribution of tritium in cells. Therefore, the reliability of the concept of average dose to organisms must be addressed. Mechanisms of DNA DBS repair: very few studies address the most deleterious form of DNA damage, which are DNA DBSs. Future studies should focus on identifying impaired DNA DBS repair pathways and kinetics, in combination with developmental and reproductive effects. The transmission of genetic d

142

Cardiac and vascular imaging with labeled platelets and leukocytes  

The contribution of platelets in atherosclerosis and thrombosis in animal models and in clinical studies has been quantified with 111In-platelet scintigraphy. New in vitro quantitative techniques have been developed using 111In-labeled platelets to determine the number of adherent platelets on deendothelialized surfaces of damaged vessel walls and synthetic vascular grafts. In vivo imaging techniques are semi-quantitative in nature; in these studies 111In radioactivity on thrombotic vessels or graft surfaces of iliac, femoral, or popliteal arteries is compared with contralateral vessels. Background 111In radioactivity in the circulating blood pool of venous and capillary networks and radioactivity in marrow decreases the sensitivity of these techniques. Subtraction of blood pool radioactivity with 99mTc-labeled autologous red cells and calculation of 111In radioactivity associated with platelet thrombus on vessel walls also have been performed for coronary, carotid, and femoral arteries. Although platelet concentrates are used frequently after open heart surgery (one to six per patient), consumption of platelets in the artificial lung or oxygenator, lysis of platelets during pumping, and suction of blood only recently have been quantified with the use of 111In-labeled platelets. These studies also demonstrated far less trauma to platelets with the use of a membrane rather than a bubble oxygenator. Further reduction in platelet consumption and trauma was observed with the use of prostacyclin, a short-acting drug with significant beneficial effect on platelet thrombus reduction and disaggregation of aggregated platelets. The role of polymorphonuclear leukocytes in inflammation, infection and myocardial infarction, and in vivo evaluation with 111In-leukocyte scintigraphy in animals and humans has been described.

143

Status of 2009 radioactivity monitoring in French Polynesia. Results of IRSN's monitoring network; Bilan de la surveillance de la radioactivite en Polynesie francaise en 2009. Resultats du reseau de surveillance de l'IRSN  

Radiological monitoring of the French environment is one of IRSN's permanent tasks as part of public policy on nuclear safety and radiological protection. It is helping to guarantee the best possible protection of the population. Exercised in Polynesia since 1962, this monitoring, which takes place on seven islands (Tahiti, Maupiti, Hao, Rangiroa, Hiva Oa, Mangareva and Tubuai) representing the five archipelagoes, consists in regularly collecting samples of various kinds from the different environmental compartments (air, water, soil, food...) with which the population may be in contact. Regarding food, the samples analyzed are representative of the diet of Polynesians living in the five archipelagoes of that territory. They come from the marine environment of the open sea, from the marine lagoon environment and from the terrestrial environment. Almost all samples are measured at the IRSN Laboratory for the Environment Study and Monitoring, based in Vairao, Tahiti Island. The 239 samples collected in 2009 were measured by Hp-Ge low background gamma spectrometry in order to be able to characterize lowest possible radioactivity levels. The levels of activity of Pu isotopes have also been determined for 17 selected samples and tritium activities for 15 water samples. The results for the year 2009 are in the continuity of a regular reduction of the levels of radioactivity since the stop, in 1974, of the French atmospheric tests. This residual radioactivity relates to primarily the {sup 137}Cs. In term of additional dose, this artificial and residual radioactivity is lower than 5 {mu}Sv.y{sup -1} (5 micro Sieverts per year). This value corresponds to less than 0, 5 % of exposure due to natural radioactivity in Polynesia (approximately 1000 {mu}Sv.y{sup -1}). (authors)

144

Situation of the surveillance of radioactivity in French Polynesia in 2006. results of the I.R.S.N. 's surveillance network; Bilan de la surveillance de la radioactivite en polynesie francaise en 2006. Resultats du reseau de surveillance de l'IRSN  

The 543 atmospheric nuclear tests released radionuclides that have deposited themselves throughout the world. The Environmental Study and Surveillance Laboratory, 'Laboratoire d etude et de suivi de l environnement' (L.E.S.E.) of the Institute of nuclear safety and radiation protection (I.R.S.N.), takes part, for more than 35 years, in the evaluation of the dosimetric consequences of these atmospheric depositions, especially those originating with the 41 tests realized in the territory of French polynesia from 1966 to 1974. This laboratory is established in Tahiti. The ingestion component of this dosimetric evaluation requires to collect the most representative samples of the feed ration of the Polynesians living in the 5 archipelagoes of this territory. These samples belong to the marine environment of full sea, the lagoon environment and the terrestrial environment. Certain samples of the physical environment are also taken (air, water). 388 samples are measured by Hp-Ge low background gamma spectrometry in order to be able to characterize lowest possible radioactivity levels. The levels of activity of Pu isotopes and {sup 90}Sr are also given for 50 selected samples and tritium activities for 14 water samples. Moreover, 101 soil samples were measured by gamma spectrometry to update the external dose due to {sup 137}Cs deposition. During the year 2006 results fall under the continuity of a regular reduction in the levels of radioactivity since the stop, in 1974 of the French atmospheric tests. This residual radioactivity relates to primarily the {sup 137}Cs. In term of additional dose, this artificial and residual radioactivity, estimated from the base of these measurements, is lower than 6 {mu}Sv by year (this maximum is obtained for the adults of the Gambiers archipelago). This value corresponds to less than 1% of exposure due to natural radioactivity in Polynesia (approximately 1 milli Sv). this value is of the same order with the estimates made for the previous years. (N.C.)

145

Distribution of the carcinogenic tryptophan pyrolysis product Trp-P-1 in control, 9-hydroxyellipticine and. beta. -naphthoflavone pretreated mice  

Autoradiograms obtained 1-4 h after i.v. injection of the /sup 14/C-labelled carcinogenic tryptophan pyrolysis product Trp-P-1 to albino and pigmented mice showed a pronounced uptake of radioactivity in the lymphatic system, in the endocrine system and in the liver, kidney medulla and brain. High radioactivity was present in the excretory pathways, predominantly in the bile/intestinal contents. At longer post-injection times most of the labelled substance had left the tissues, except for the liver. Trp-P-1 is known to be activated by cytochrome P-448. The uptake of radioactivity in the liver could be reduced by pretreatment with the cytochrome P-448 inhibitor 9-hydroxyellipticine suggesting that the observed accumulation of radioactivity in the liver was partly due to metabolites of Trp-P-1. After pretreatment with the cytochrome P-448 inducer ..beta..-naphthoflavone, the administration of Trp-P-1 resulted in a highly selective accumulation of radioactivity in the lung parenchyma, exceeding all other tissues. ..beta..-Naphthoflavone pretreatment also increased the uptake of radioactivity in the kidney cortex and small intestinal mucosa. As indicated by a high labelling of the pigmented tissues of the maternal and fetal eye, the carcinogen and/or its metabolites were accumulated in melanin.

146

2-Methylthioadenosine[beta-32P]diphosphate. An agonist and radioligand for the receptor that inhibits the accumulation of cyclic AMP in intact blood platelets.  

2-Methylthio-ADP and its radioactive analogue [beta-32P]2-methylthio-ADP were synthesized and used to investigate platelet receptors for ADP. 2-Methylthio-ADP induced platelet aggregation and shape change, and inhibited cyclic AMP accumulation in platelets exposed to prostaglandin E1. Compared with ...

147

Nuclear waste disposal utilizing a gaseous core reactor  

The feasibility of a gaseous core nuclear reactor designed to produce power to also reduce the national inventories of long-lived reactor waste products through nuclear transmutation was examined. Neutron-induced transmutation of radioactive wastes is shown to be an effective means of shortening the apparent half life.

148

Artist rendering of the GLAST satellite.  

Aug 26, 2008... scientists tested and calibrated its two instruments, the Large Area ... The image's third pulsar, named Geminga and located in Gemini, is not a radio source. ... from academic institutions and partners in France, Germany, Italy, Japan, ... for his work on induced radioactivity and is today regarded as one of ...

149

Print  

Aug 26, 2008... June 11 launch, scientists tested and calibrated its two instruments, the ... The image's third pulsar, named Geminga and located in Gemini, is not a radio source. ... academic institutions and partners in France, Germany, Italy, Japan, ... for his work on induced radioactivity and is today regarded as one of ...

150

Characterization of 1-methyladenine binding in starfish oocyte cortices.  

1-Methyladenine (1MeAde) is the naturally occurring maturation-inducing hormone of starfish oocytes. We have prepared a biologically active [3H]1MeAde of high purity and relatively high specific radioactivity. This ligand binds to cortices isolated from full-grown prophase-arrested oocytes of the st...

151

Topics in radiation at accelerators: Radiation physics for personnel and environmental protection  

This report discusses the following topics: Composition of Accelerator Radiation Fields; Shielding of Electrons and Photons at Accelerators; Shielding of Hadrons at Accelerators; Low Energy Prompt Radiation Phenomena; Induced Radioactivity at Accelerators; Topics in Radiation Protection Instrumentation at Accelerators; and Accelerator Radiation Protection Program Elements.

152

I ! I I - NASA Technical Reports Server  

source strengths, doses, and dose rates due to neutron induced activation of materials. This .... isotopic atom densities to compute gamma ray source strengths as a function of time for each decay chain ...... radioactive decay chain as ...... AAEC/TM. 196. (1963). S. Podgor and. L. A.. Beach,. Regularities in. Thermal. Neutron ...

153

Effects of low-level radioactive-waste disposal on water chemistry in the unsaturated zone at a site near Sheffield, Illinois, 1982-84  

A 1982-84 field study defined the chemistry of water collected from the unsaturated zone at a low-level radioactive-waste disposal site near Sheffield, Bureau County, Illinois. Chemical data were evaluated to determine the principal naturally occurring geochemical reactions in the unsaturated zone and to evaluate waste-induced effects on pore-water chemistry.\\r\

154

ISOLDE beams of neutron-rich zinc isotopes: yields, release, decay spectroscopy  

Intense radioactive ion beams of the neutron-rich zinc isotopes 69-81Zn have been produced at the isotope separation on-line facility ISOLDE at CERN. The combined use of spallation-neutron induced fission of 238UCx targets and resonant laser ionization provided sufficient suppression of disturbing isobars (mainly gallium and rubidium) to perform decay spectroscopy up to 81Zn.

155

Study of induced valence transitions in MgEu systems by obervation of perturbed angular distribution of gamma rays  

Induced valence transitions in MgEu systems were studied by observation of the angular distribution of gamma rays in radioactive Eu. Anisotropy measurements were obtained by the measurement of statistical covariance at 90/sup 0/ and 180/sup 0/ for the 1408 kev - 122 kev gamma rays pair. Changes in typical interatomic distance, as a consequence of cold working, were obtained.

156

Mass determination of molecules of biological interest by fast heavy ions induced desorption mass spectrometry  

It has been shown recently that fast heavy ions can induce a mild desorption of organic molecules deposited on a thin foil, when passing through the foil. A time of flight mass spectrometer, originally developed to identify the mass of radioactive nuclei, has been slightly transformed to allow the d...

157

High resolution gamma-ray spectroscopy with a radioactive beam  

The gamma-rays de-exciting the yrast states in neutron deficient nuclei around A-55 have been observed from fusione-vaporation reactions induced by an intense radioactive Ne-19 beam on a Ca-40 target. An array of escape suppressed germanium detectors recorded reaction gamma-rays. Background subtract...

158

Performance of the ARES recoil separator for (p, gamma) reaction measurements  

In Louvain-la-Neuve, the Astrophysics REcoil Separator (ARES), was installed to measure (p, gamma) reactions of astrophysical interest induced by radioactive beams. ARES was coupled to the CYCLONE44 cyclotron. First tests performed with an F-19 stable beam, i.e., the H(F-19 Ne-20)gamma reaction, are...

159

Star, a Solenoid and Telescope for Astrophysical Research  

A set-up dedicated to the measurement of radiative capture reactions induced by proton-rich radioactive beams in reverse kinematics is described; this set-up was used to measure the Ne-19(p, gamma)Na-20 reaction, of astrophysical interest. In addition, the relative merits of two hydrogen targets, i....

160

expected gamma-ray emission spectra from the lunar surface as a ...  

The gamma-rays emitted from the moon or any similar body carry informa- tion on the chemical ... remains the problem of deriving the actual photon flux from the observed pulse ... gamma-rays resulting from the decay of induced-radioactive nuclei are calcu- lated here. ...... Simulation experiments using accelerators, and ...

 
 
 
 
161

Chloride permeability of membrane vesicles isolated from Torpedo californica electroplax.  

The Cl- permeability of membrane vesicles prepared from the electric organ of the marine ray Torpedo californica was studied by means of radioactive tracer exchange and by measuring the changes in the scattered-light intensity caused by osmotically induced volume changes. Both types of experiments i...

162

Defect annealing in Sb/Sn implanted diamond investigated with 119Sn Mössbauer spectroscopy  

The annealing of defects in Sb/Sn implanted diamond has been studied in 119Sn Mössbauer spectroscopy following the implantation of radioactive parent isotopes 119Xe and 119mSn. Our results show that after annealing above 1300K, 40% of the implanted ions are located at or near regular sites in the lattice. Significant implantation induced defects however remain.

163

The development and application of advanced analytical methods to commercial ICF reactor chambers. Final report  

Progress is summarized in this report for each of the following tasks: (1) multi-dimensional radiation hydrodynamics computer code development; (2) 2D radiation-hydrodynamic code development; (3) ALARA: analytic and Laplacian adaptive radioactivity analysis -- a complete package for analysis of induced activation; (4) structural dynamics modeling of ICF reactor chambers; and (5) analysis of self-consistent target chamber clearing.

164

Specific cyclotron correlations under space charge effects in the case of a spherical beam  

High intensity primary ion beams at GANIL are necessary to induce high radioactive production rates in the frame of the SPIRAL project. In this paper, we show that an intense beam can be tuned at injection in a cyclotron so as to result in a spatially spherical beam in the machine, with a reduced halo formation. (authors)

165

Gamma-Ray Induction of Malignant Tumors in Rats  

Sources of protracted gamma radiation adjacent to bone were found to induceosteogenic sarcoma in half of the exposed males. Osteogenic sarcomas appeared in 3 males remote from the radioactive sources and may not have been radiation induced. Some tumors were small enough so that the site of origin co...

166

10 CFR 20.1003 - Definitions.  

...source is defined as radioactive material that is sealed in a capsule or closely bonded, in a solid form and which is not...threshold is believed to exist. Radiation-induced cataract formation is an example of a nonstochastic effect (also called a...

167

Enzymes Induced in a Bacterium by Growth on Sodium Dodecyl Sulfate  

Alkyl sulfatase was induced by growth on nutrient broth plus sodium dodecyl sulfate (SDS) in a bacterium we have designated Pseudomonas C12B. Measurement of the radioactivity of S35O4= released from SDS35 by the enzyme in cell-free extracts provided an effective assay technique. The barium chloranil...

168

The use of EXOGAM for in-beam spectroscopy of proton drip-line nuclei with radioactive ion beams  

One of the first fusion?evaporation experiments using radioactive ion beams was performed at GANIL in order to study proton-rich nuclei of the light rare-earth region. The low production cross-section of the exotic species of interest, in combination with the low intensity of the beam and its induce...

169

Determination of representative spectra for the characterization of waste from a 450 GeV proton accelerator (SPS, CERN) Determinering av representativa spektrum för karaktärisering av avfall från en 450 GeV protonaccelerator (SPS, CERN)  

  Radioactive waste has been accumulated at CERN as unavoidable consequence of the use of particle accelerators. The elimination of this waste towards the ?nal repositories in France and Switzerland requires the determination of the radionuclide inventory. In order to calculate the residual induced ...

170

DNA-BENZO(A)PYRENE ADDUCTS FORMED IN A 'SALMONELLA TYPBIMURIUM' MUTAGENESIS ASSAY SYSTEM  

The DNA adducts formed in Salmonella typhimurium when bacteria are incubated with radioactive benzo(a)pyrene and liver microsomal enzymes from several sources has been investigated. When enzyme prepartions from Aroclor 1254 or 3-methylcholanthrene induced C57BL/6N (B6) mice were ...

171

Vitamin D3- Induced Histological Changes in the Corpuscles of Stannius of a Freshwater Catfish, Heteropneustes Fossilis Kept Either in Artificial Freshwater, Calcium-rich Freshwater or Calciumdeficient Freshwater  

Summary: Vitamin D3 (50I. U. /100 g body wt) was injected day intraperitoneally to the fish H. fossilis maintained in artificial freshwater, calcium-rich freshwater and calcium deficient freshwater. The animals were killed on day 1,3,5, and 10. The serum calcium levels were estimated and CS were fixed for histological studies.Administration of vitamin D3 induced hypercalcemia in the fish kept in all the three different media.The AF-positive cells of CS of vitamin D3 treated specimens kept in artificial freshwater, calcium-rich freshwater and calcium-deficient freshwater depict hyperactivity which is expressed by their degranulation and increased nuclear volume.The AF-negative cells of CS of vitamin D3-treated fish kept in artificial freshwater have not shown any change, however, the AF-negative cells of the fish treated with vitamin D3 and maintained in calcium-rich freshwater and calciumdeficient freshwater exhibit a decrease in their nuclear volume.   

172

Artificial photosynthesis for solar water-splitting  

Hydrogen generated from solar-driven water-splitting has the potential to be a clean, sustainable and abundant energy source. Inspired by natural photosynthesis, artificial solar water-splitting devices are now being designed and tested. Recent developments based on molecular and/or nanostructure designs have led to advances in our understanding of light-induced charge separation and subsequent catalytic water oxidation and reduction reactions. Here we review some of the recent progress towards developing artificial photosynthetic devices, together with their analogies to biological photosynthesis, including technologies that focus on the development of visible-light active hetero-nanostructures and require an understanding of the underlying interfacial carrier dynamics. Finally, we propose a vision for a future sustainable hydrogen fuel community based on artificial photosynthesis.

173

Effect of atropine and gammahydroxybutyrate on ischemically induced changes in the level of radioactivity in (/sup 3/H)inositol phosphates in gerbil brain in vivo  

Brain ischemia in gerbils was induced by ligation of both common carotid arteries for 1 min or 10 min. Sham-operated animals served as controls. Intracerebral injection of (3H)inositol into gerbil brain 16 hr before ischemic insult resulted in equilibration of the label between inositol lipids and water-soluble inositol phosphate. A short ischemic period (1 min) resulted in a statistically significant increase in the radioactivity of inositol triphosphate (IP3) and inositol monophosphate (IP), by about 48% and 79%, respectively, with little change in that of the intermediate inositol biphosphate (IP2), which increased by about 16%. When the ischemic period was prolonged (10 min), an increase in the radioactivity of inositol monophosphate exclusively, by about 84%, was observed. The level of radioactivity in inositol phosphates IP2 and IP3 decreased by about 50%, probably as a consequence of phosphatase activation by the ischemic insult. The agonist of the cholinergic receptor, carbachol, injected intracerebrally (40 micrograms per animal) increased accumulation of radioactivity in all inositol phosphates. The level of radioactivity in IP3, IP2, and IP was elevated by about 40, 23, and 147%, respectively. The muscarinic cholinergic antagonist, atropine, injected intraperitoneally in doses of 100 mg/kg body wt. depressed phosphoinositide metabolism in control animals. The level of radioactivity in water-soluble inositol metabolites in the brain of animals pretreated with atropine was evidently about 32% lower than in untreated animals. Pretreatment with atropine decreased the radioactivity of all inositol phosphates in the brain of animals subjected to 1-min ischemia and the radioactivity of IP in the case of 10-min brain ischemia.

174

General aspects of the cyclotrons and radiochemical separation of: {sup 11} C, {sup 15} O, {sup 18} F and {sup 14} N; Aspectos generales de los ciclotrones y separacion radioquimica de {sup 11} C, {sup 15} O, {sup 18} F y {sup 14} N  

The particle accelerators, as the cyclotrons, are extraordinarily important as tools for the radioisotope production and its application in the area of the medicine. In this time, another method exists for the production of artificial radioisotopes, based on the irradiation of samples with alpha particles or with neutrons coming from a natural radioisotope being obtained a neutron source (Ra + Be, Rn + Be, Po + Be). However, its can be obtained a great quantity of radioisotopes by means of cyclotrons in very short time, compared with other methods. After the second world war, artificial radioisotopes took place by means of reactors and its had many applications, not only medical and in little time the accelerators were manufactured that were more indispensable that the reactors to produce radioisotopes with medical aims. For this reason, the accelerators, in few years became in machines very important for the production of artificial radioisotopes and consequently its were developed techniques of radioactive traces progressively more sophisticated, since it is evident that the production of radioactive nuclei through nuclear reactors its cannot satisfy all the demands. In general terms, only the neutrons can be used as nuclear projectiles in reactors and as a result, the production spectra of radioisotopes is limited and as alternative it is unavoidable that the cyclotrons are a good tool for this end. The use of a cyclotron to produce radioisotopes, it can be justified, only if the following conditions are completed. 1. If the radioisotopes of an element produced in a reactor don't favor with the nuclear properties for the purposes of the traced studies, for example: if the half life is very short or very big, if the decay system not to suit him. 2. If the wanted radioisotope cannot produce in the reactor with enough specific activity. (Author)

175

Male Sterility in three crop Lupinus species  

Abstract Male sterility is described for the first time in lupin crop species Lupinus angustifolius L. and Lupinus luteus L. and is also characterized in the Andean lupin, Lupinus mutabilis Sweet. In L.angustifolius and L.luteus, male-sterile plants were identified in artificially induced mutation populations, while in L.mutabilis, both naturally occurring and induced male-sterile plants were selected. For L.angustifolius artificially induced sterility, the segregation ratios in F1, F2 and backcrosses showed a single-gene recessive inheritance and was concluded to be of a nuclear rather than cytoplasmic form. In L.luteus, male-sterile plants were recovered from an M3 mutation population derived from cv. -Wodjil-, and several were consistent with that of single recessive gene, most likely n...

176

Radiation-induced neoplasms of the brain  

The histopathology of two patients with radiation-induced neoplasms of the brain following therapeutic irradiation for intracranial malignancies is described. The second neoplasms were an atypical meningioma and a polymorphous cell sarcoma, respectively. They occurred 12 and 23 years after irradiation (4000 rad), within the original field of irradiation. In both cases, the radiation-induced tumors were histologically distinct from the initial medulloblastomas. Both patients were retreated with local irradiation using permanent implantation of radioactive iodine-125 seeds.

177

Effect of drying on argillite samples  

The ventilation in underground galleries during the exploitation phase of a radioactive waste disposal will induce an unsaturated zone in the host rock. The suction gradient due to the drying can induce tensile stress which could modify the excavation damaged zone (EDZ). Such a situation has already been evidenced at Tournemire where tensile cracks occur due to the relative humidity changes. The purpose of the study is to investigate the effects of desaturation on Bure argillite samples submitted to decreasing relative humidity. (authors)

178

Assessment of the amount of lung tumors induced by radon and radon-daughter-products in the Netherlands. Schatting van het aantal longtumoren veroorzaakt door radon en radon-dochterprodukten in Nederland  

Radon is a radioactive noble gas. After the decay of radon, the daughter products become attached to dust particles. The inhaled dust particles can induce lung tumours by the alpha radiation they emit. In this article an assessment is given for the amount of deaths caused by radon induced lung tumors in the Netherlands and the dispersion as result of the uncertainties of the risk factors. (R.B.). 22 refs.; 2 figs.; 1 tab.

179

Maximizing Accuracy in Half Life Measurements, by Minimizing Error, with Application to BISMUTH-212 and POLONIUM-218  

Radon and short-lived progeny existing in all three primordial series, namely uranium, thorium and actinium, are of most significance for human exposure, since their inhalation is implicated in bronchogenic carcinoma. Because the dosimetric calculations utilize half-life, it is important to know this parameter with the maximum possible accuracy. The half-lives of Po-218 and Bi-212, radon-222 and radon-220 progeny, were measured as 3.078 +/- 0.01 min and 59.81 +/- 0.23 min respectively. Experimental data collected by alpha-counting included background from both the counter and the intrinsic radioactivity. A comparison of all mathematical methods presently employed in the analysis of experimental radioactivity decay is presented. The most commonly used methods are, the least squares, the weighted least squares with different weighting factors and the maximum likelihood (Peierls) method. Artificial data corresponding to three different nuclides, different total experimental duration, and different counting time intervals were generated. Testing these data showed that the WLSQ with the correct weighting factor gives the higher accuracy and precision. Without spectrometry, it is impossible to measure the quantity or half-life of Po-218 unless correction is made for the Po-214 daughter. For the measurement of Po-218, samples containing the short-lived radon-222 daughters were collected electrostatically. A method used to estimate the initial radon daughters concentration in air based on regression analysis is proposed. The comparison of this with the well known Thomas method using artificial data showed that the regression analysis method leads to more accurate results. The Bi-212 samples were prepared from a Th-228 solution by spontaneous electrodeposition on platinum and nickel disks. Corrections for the curve stripping have been applied. The methods developed here have general application to the measurement of any radioactive nuclides. A review of the measured half-lives of the uranium series isotopes is presented in a summary table. All the reported values in the literature are included. Mean values were calculated and suggested as today's "best" available data.

180

Genetically controlled fusion, exocytosis and fission of artificial vesicles-a roadmap  

Artificial vesicles represent ideal candidates as a model for artificial cells. It was shown that artificial genetic programs and the required cellular machinery (cell-free expression systems) can be incorporated into vesicles and allow the synthesis of proteins (Noireaux et al. 2005). Vesicles were shown to fuse if a special class of viral proteins, termed fusogenic peptides, were added to the external medium (Nomura et al. 2004). In the present work, we intend to develop genetically controlled fusion, fission and exocytosis of vesicles by the synthesis of peptides within vesicles. First, we enclosed synthesized peptides in vesicles to induce in a next step fusion of adjacent vesicles, fission and exocytosis of nested vesicles. Second, we will replace the peptides by an enclosed cell-free expression system to internally synthesize fusion peptides. To control the gene expression, different mechanisms are available, e.g. addition of transcription factors (Kelley et al. 2010). Changes in the pH are reported to control the activity of the fusion peptides (Nomura et al. 2004). So far, we successfully enclosed a commercially available cell-free system and expressed eGFP in vesicles as a proof of principle. Furthermore, we optimized the already established protocol (Hadorn et al. 2011) to produce nested vesicles in the presence of peptides. This project may present an important step towards an artificial cell. Especially vesicle division is discussed as one of the upcoming challenges in designing an artificial cell (Noireaux et al. 2011). Moreover, it may become important in personalized drug delivery.

 
 
 
 
181

Environmental radioactivity surveillance programme. 1999 and 2000  

The Radiological Protection Institute of Ireland continued to monitor levels of radioactivity in air, drinking water and foodstuffs in 1999 and 2000 and the results are presented in this report, the sixth in a series dealing with the terrestrial environment. Radioactivity is present in the terrestrial environment due to natural processes, the testing of nuclear weapons in the atmosphere, accidents such as the Chernobyl accident and the routine discharge of radionuclides from nuclear installations. The Institute monitored airborne radioactivity at ten stations throughout the country. One site was equipped to detect the presence of krypton-85, a radionuclide which is released into the environment primarily as a result of the reprocessing of nuclear fuel at installations such as Sellafield in the UK and La Hague in France. Both in 1999 and 2000, levels of radionuclides in airborne particulates were low and consistent with measurements in previous years. Public water supplies are sampled from each county at least every four years with supplies to certain major population centres sampled annually. Water supplies from eleven counties were sampled between 1999 and 2000 and all of the waters tested were found to be within legal requirements for water quality from a radiological point of view. The levels of artificial radioactivity in milk and other foodstuffs such as milk products, baby foods, beef, lamb, poultry and vegetables continued to be very low in 1999 and 2000 and, for the majority of samples, below the detection limits. External gamma dose rates were monitored continuously at twelve locations around the country. The dose rate was recorded every twenty minutes and the readings transmitted automatically to the Institute's computer database at Clonskeagh (Dublin). No abnormally high levels were observed at any of the twelve stations in either 1999 or 2000. The data presented in this report demonstrate that the levels of artificial radioactivity in the Irish terrestrial environment, including foodstuffs, remain extremely low and do not pose a significant risk to health. Nonetheless, the Radiological Protection Institute of Ireland remains vigilant and will continue to monitor the exposure of people living in Ireland to all relevant sources of ionising radiation. (author)

182

Development and study of airborne spectrometer system being compatible with nuclear emergency monitoring  

The exploitation and use of nuclear energy are of great importance to developing of national economy and maintaining state security. But it also has a possibility of serious accident. Based on the principles of airborne gamma ray spectrometry in the uranium exploration, nuclear emergency monitoring has been developed. This method has high sensitivity to the radioactive nuclides in the air and on the ground, and with the advantage of fast measuring in large area. Hence, in the middle of 1980s, some developed countries began to survey the scope and degree of nuclear accident contamination and environmental radiation level monitoring in the surrounding nuclear facilities, it can also be used to search for the lost radioactive sources. According to the actual situation and compatible guideline, National Nuclear Emergency Office consigned this project to our Center. After development and study on the Airborne gamma ray spectrometer system associated NaI(Tl) used for the uranium exploration, a compatible spectrometer system associated NaI(Tl) was established in a short period by us, which can fulfill airborne nuclear emergency survey basically. In normal situation, it was proved that the start-up time is less than two hours including transport to the airport. The system has high sensitivity to radioactive plume of {sup 41}Ar and can respond rapidly to artificial sources, such as {sup 192}Ir, {sup 60}Co, {sup 137}Cs and {sup 131}I etc.

183

Technical Reviews on the Radioisotope Application for Leak Detection in Reservoirs  

The previous techniques on the detection of leaks from reservoirs are difficult to identify the leak points and leak pathways in reservoirs. Additionally the complexity and ambiguity of data analysis resulted from them can increase the failures of leak detection. While, The technique using radioisotope as a tracer is considered to be very promising. In the same context, systematic studies led by IAEA are being practiced by organizing the task force team. The detection technique using natural tracer can give information about the age of ground water and the interconnection between ground water and reservoir water and the seepage origin. On the other hand, the one using artificial tracer can identify the leak point in reservoirs directly, in which radioactive cloud migration method and radioactive tracer adsorption method are included. The former is using hydrophilic radioisotope tracer, and the latter adsorptive radioisotope tracer which is emitting gamma ray. The radiotracer are injected at a point of the reservoir near to the bottom. Afterwards, the migration of the radioactive tracer is followed by means of submerged scintillation detectors suspended from boats. Usually {sup 131}I, {sup 82}Br, {sup 46}Sc, and {sup 198}Au etc. can be used as tracer. The point reaching the maximum concentration of tracer corresponds to the leak point in reservoirs.

184

Environmental radioactivity and radiation exposure in Switzerland 1995; Umweltradioaktivitaet und Strahlendosen in der Schweiz 1995  

Switzerland has been performing systematic monitoring of radioactivity in the environment and in food for forty years. This report contains the results of measurements made in the course of 1995 and the consequential radiation doses for the population. The monitoring programme deals with radioactivity in the atmosphere, precipitation, aquatic systems, soil, grass, foodstuffs and the human body, but also includes natural radiation, doses due to radon inside dwellings, emissions from nuclear power stations and other operations using radionuclides, as well as miscellaneous radiation sources. All the nuclear power plants and other facilities licensed to handle radioactive substances remained within their annual release limits in 1995, and environmental measurements revealed no inadmissible immission or dose values. The population`s mean annual radiation dose totals 4 mSv, with some 40% of this due to radon in the home (but with extreme values as high as 100 mSv), another 30% coming from natural radiation, a quarter from medical applications and less than 5% from artificial radiation. (author) figs., tabs., refs.

185

Radioactivity and element concentrations in the coastal bottom sediments in the vicinity of Yonggwang nuclear power plant  

In order to evaluate the influence of nuclear power plant operation on nearby coast, the radioactivity and element concentrations in coastal bottom sediments were investigated. The coastal bottom sediments were collected at 179 sampling stations around the Yonggwang nuclear power plant and analyzed for radioactivity by HP-Ge {upsilon}-spectrophotometer and Low Background {alpha}/{beta} Counter, and heavy metals by ICP-AES and AAS. In addition, particle size distribution in a number of sediments were measured and compared with other analytical results. According to the result of grain size distribution, most sediments are classified as silt loam with 23 percent sand, 65 percent silt and 12 percent clay contents. The radioactivities of most nuclides except {sup 137}Cs are below the limit of detection, and artificial nuclide of {sup 137} Cs may derived from past nuclear weapon tests. The heavy metal concentrations are within the normal range of marine sediments and the anomaly caused by the operation of nuclear power plant has not been monitored. (author). 7 refs., 2 tabs., 3 figs.

186

Krypton gas cylinders as a source of radiation.  

A standard 40 foot shipping container with a cargo of pressurized krypton gas in 159 steel cylinders, which had triggered a radiation alarm, was investigated to address radiation safety and illicit nuclear trafficking concerns. The investigation included contamination and dose rate measurements as well as in situ high resolution gamma spectroscopy. The dose rate measurements gave a maximum value of 0.07 microSv h(-1) above background (0.08 to 0.11 microSv h(-1)) on the cylinder surface and no detectable increase above background at distances of 1 m and higher. Contamination monitor readings showed a similar relative increase (plus 8 cpm) above background (about 12 cpm) to the dose rate readings. Quantitative gamma spectroscopy revealed a contamination of the gas with 85Kr at a level of 3.5 x 10(5) Bq kg(-1). This value was found to be consistent with analytical and numerical estimates based on current data for atmospheric 85Kr, which is captured from ambient air together with stable krypton during the production process. This incident demonstrates an apparent lack of radiation-related knowledge by those who handle krypton gas, as well as by border control personnel and emergency responders. We therefore propose to improve labeling and documentation standards for such shipments. This effort may be facilitated by introducing the new category of "technically enhanced artificial radioactive material," or "TEARM" (similar to the existing "naturally occurring radioactive material" or "NORM" and "technically enhanced naturally occurring radioactive material" or "TENORM" categories). PMID:20539125

187

Contact zones and hydrothermal systems as analogues to repository conditions  

Radioactive waste isolation efforts in the US are currently focused on examining basalt, tuff, salt, and crystalline rock as candidate rock types to encompass waste repositories. As analogues to near-field conditions, the distributions of radio- and trace-elements have been examined across contacts between these rocks and dikes and stocks that have intruded them. The intensive study of the Stripa quartz monzonite has also offered the opportunity to observe the distribution of uranium and its daughters in groundwater and its relationship to U associated with fracture-filling and alteration minerals. Investigations of intrusive contact zones to date have included (1) a tertiary stock into Precambrian gneiss, (2) a stock into ash flow tuff, (3) a rhyodacite dike into Columbia River basalt, and (4) a kimberlite dike into salt. With respect to temperature and pressure, these contact zones may be considered "worst-case scenario" analogues. Results indicate that there has been no appreciable migration of radioelements from the more radioactive intrusives into the less radioactive country rocks, either in response to the intrusions or in the fracture-controlled hydrological systems that developed following emplacement. In many cases, the radioelements are locked up in accessory minerals, suggesting that artificial analogues to these would make ideal waste forms. Emphasis should now shift to examination of active hydrothermal systems, studying the distribution of key elements in water, fractures, and alteration minerals under pressure and temperature conditions most similar to those expected in the near-field environment of a repository. 14 refs.

188

Induced chemical defenses in a freshwater macrophyte suppress herbivore fitness and the growth of associated microbes.  

The freshwater macrophyte Cabomba caroliniana induces a chemical defense when attacked by either the crayfish Procambrus clarkii or the snail Pomacea canaliculata. Induction by either consumer lowers the palatability of the plant to both consumers. When offered food ad libitum, snails feeding on non-induced C. caroliniana grew 2.6-2.7 times more than those feeding on induced C. caroliniana. Because snails fed less on induced plants, this could be a behavioral effect (reduced feeding), a physiological effect of the induced metabolites on the consumer, or both. To assess these possibilities, we made artificial diets with lipid extracts of induced versus non-induced C. caroliniana and restricted control snails to consuming only as much as treatment snails consumed. Growth measured as shell diameter was significantly lower on the diet containing extract from induced, as opposed to non-induced, plants; change in snail mass was more variable and showed a similar, but non-significant, trend. Thus, snails may reduce feeding on induced plants to avoid suppression of fitness. The induced defenses also suppressed growth of co-occurring microbes that might attack the plant through herbivore-generated feeding scars. When two bacteria and three fungi isolated from C. caroliniana surfaces were cultured with the lipid extract from induced and non-induced C. caroliniana, both extracts inhibited the microbes, but the induced extract was more potent against three of the five potential pathogens. Thus, induced plant defenses can act against both direct consumers and microbes that might invade the plant indirectly through herbivore-generated wounds. PMID:20927537

189

Innovative approach to ash radioactivitiy and health impacts of lignite power plants  

In Macedonia nearly 90% of the present electricity production utilizes domestic low-calorie lignite, and this is likely to continue for the next few decades. Local and global environmental impacts of fossil fuel utilization are considered. Some innovative extensions to standard methodologies of environmental risk assessment and management are considered. They involve ash radioactivity and psychosomatic health impacts from lignite power plants. Two extensions are proposed: one comprising complete radioactive chains when determining committed effective dose from lignite ash; the other by including the psychosomatic diseases, such as peptic ulcer and arterial hypertension, due to chronic stress induced by power plants during normal operation. 7 refs., 2 figs., 3 tabs.

190

Radioactivation in ''quiet'' sections of the SSC (Superconducting Super Collider)  

Estimation of induced radioactivity in the ''quiet'' sections of the SSC is approached using elementary methods. Estimates are given of total activity and residual dose rates on the surface of magnets in the quiet regions, as well as estimates of the activation of tunnel concrete. The residual radioactivity produced in the magnets and concrete walls of the ''quiet'' regions of the SSC are found to be quite small and of little radiological impact, but that simple scaling could yield results for more ''lossy'' regions. (LEW)

191

Potential of pottery materials in manufacturing radioactive waste containers  

Various pottery materials were evaluated for possible use in manufacturing containers for radioactive waste. Their potential was examined from the viewpoints of the effectiveness of disposal and the changes induced in them by gamma rays. Samples of these materials were irradiated with high-energy neutrons and gamma rays in a reactor near its core. the physical and mechanical properties of the materials before and after gamma irradiation (in a {sup 60}Co gamma cell) were compared. The study showed that pottery materials are resistant to radiation. Therefore, they were proposed for manufacturing drums for disposal of radioactive waste of high gamma activity.

192

Operational radiation protection in high-energy physics accelerators.  

An overview of operational radiation protection (RP) policies and practices at high-energy electron and proton accelerators used for physics research is presented. The different radiation fields and hazards typical of these facilities are described, as well as access control and radiation control systems. The implementation of an operational RP programme is illustrated, covering area and personnel classification and monitoring, radiation surveys, radiological environmental protection, management of induced radioactivity, radiological work planning and control, management of radioactive materials and wastes, facility dismantling and decommissioning, instrumentation and training. PMID:19812129

193

Comparison of dna-copying fidelity during repair and semiconservative synthesis by radioactive precursor distribution analysis  

The authors compare the fidelity of DNA copying during semiconservative and reparative synthesis under normal conditions and during cortisol-induced activation of free-radical processes, by examining the distribution of radioactivity among DNA pyrimidine isopliths. Radioactivity of nucleotide material in the isopliths was measured by counting in appropriate zones of the chromatograms in toluene scintillator. The investigation shows that injury to DNA of different organs, both directly and as a result of faulty repair, leads to shortening of the pyrimidine isopliths, i.e., to changes in the primary structure of DNA. These data help to explain the simultaneously cytostatic, carcinostatic, and mutagenic action of irradiation, cortisol and hydroxyurea.

194

Gamma-ray spectroscopy of sup 3 sup 4 Mg via RI beam fragmentation  

A novel technique with a radioactive isotope beam has been employed for in-beam gamma-ray spectroscopy of a very neutron-rich isotope sup 3 sup 4 Mg. The excited sup 3 sup 4 Mg were produced by the projectile fragmentation reaction induced by a radioactive sup 3 sup 6 Si beam at 50 MeV/nucleon on a 385 mg/cm sup 2 sup 9 Be target. Deexcitation gamma rays were detected in coincidence with the sup 3 sup 4 Mg fragments. The measured excitation energy, 660+-10 keV, implies a large deformation of sup 3 sup 4 Mg.

195

Low-level counting techniques in the underground laboratory `Felsenkeller` in Dresden  

Low radioactivity measurements are characterized by low detection limits. They are mainly determined by the background. The contribution of cosmic rays may be reduced drastically by installation of measurement devices in an underground laboratory. In 1982 we installed a chamber with a shield of ultramafic rock for low-level measurements within a cave of an old brewery named `Felsenkeller`. In this laboratory we used low-level {gamma}-spectrometry for the measurement of neutron activated samples of semiconductor silicon (Niese (1986)), of cosmic induced radioactivity in meteorites, chemically separated long-lived nuclides in low-level wastes, contaminated materials and of environmental samples. (orig./DG)

196

Cationised gelatin and hyaluronic acid coating enhances polyethylene terephthalate artificial ligament graft osseointegration in porcine bone tunnels.  

PURPOSE: The aim of this study was to investigate whether cationised gelatin and hyaluronic acid (CH) coating could induce polyethylene terephthalate (PET) artificial ligament graft osseointegration in the bone tunnel. METHODS: Surface modification of PET artificial ligament graft was performed by layer-by-layer (LBL) self-assembly CH coating. Six pigs underwent anterior cruciate ligament (ACL) reconstruction on the right knees, with three pigs receiving the CH-coated PET grafts and the other three pigs non-CH-coated PET grafts as controls. They were sacrificed at three months after surgery and the graft-bone complexes were acquired for computed tomography (CT) scan and histological examination. RESULTS: CT scans showed a significant difference at the distal femoral site (p?=?0.031) or at the distal tibial site (p?=?0.0078), but no significant difference in the bone tunnel areas' enlargement at other sites (p?>?0.05) between the CH group and the control group. Histologically, application of CH coating induced new bone formation between graft and bone at three months compared with the controls at the distal site. The interface width of the CH group was significantly lower than that of the control group at the distal femoral site (p?=?0.0327) and at the distal tibial site (p?=?0.0047). CONCLUSIONS: The study has shown that CH coating on the PET artificial ligament surface has a positive biological effect in the induction of artificial ligament osseointegration within the bone tunnel at the distal site of the bone tunnel. PMID:23132501

197

UV irradiation-induced modification of photonic band gap and birefringence in artificial opal nanocomposite  

A red shift of the photonic band gap and stress-induced birefringence have been observed in the bare and ZnO infilled artificial opal samples under UV laser irradiation. The stress-induced birefringence appeared between the irradiated and non-irradiated parts of the opal. These effects were related to the irradiation-stimulated increase in the density and the refractive index of the opal. Using the obtained results, the UV illumination-induced changes in the degree of polarization, volume and refractive index of the opal were estimated.

198

UV irradiation-induced modification of photonic band gap and birefringence in artificial opal nanocomposite  

A red shift of the photonic band gap and stress-induced birefringence have been observed in the bare and ZnO infilled artificial opal samples under UV laser irradiation. The stress-induced birefringence appeared between the irradiated and non-irradiated parts of the opal. These effects were related to the irradiation-stimulated increase in the density and the refractive index of the opal. Using the obtained results, the UV illumination-induced changes in the degree of polarization, volume and refractive index of the opal were estimated.

199

Synthesis and decay properties of superheavy atoms in nuclear reactions induced by stable and radioactive ion beams  

This talk consists of two parts. The first one presents the results of investigations performed in 1998-2000 in Dubna on the synthesis of superheavy nuclei in reactions induced by {sup 48}Ca ions. The radioactive decay properties of the nuclei, indicating a considerable increase in the {alpha}-decay and spontaneous fission half-lives of the isotopes of elements 110-116 when approaching the closed neutron shell at N=184, are given. In the second part the possible ways of advancing into the region of more neutron-rich nuclei, using stable and radioactive ion beams, are discussed. Since so far no intense radioactive ion beams are available, some experiments with stable beams are considered as a test for the suggested ideas. (orig.)

200

A new method for fast neutron dosimetry with a circulating liquid  

A new approach to fast-neutron dosimetry is described. It involves circulating a liquid with dissolved chemicals between a localized neutron field and a remote area where neutron-induced radioactivities are measured continuously. This approach employs reactions which generate relatively short-lived radioactive byproducts. Sensitivity to the neutron energy spectrum is achieved by choosing several reactions with differing thresholds. Neutron field strengths and their time variations can be derived from experimental data using the known radioactive-decay properties, cross sections, detector efficiencies, liquid flow rates and composition of the liquid. The concept has been demonstrated by measurements which utilized an aqueous solution of yttrium chloride hexahydrate, a 14-MeV neutron generator and Ge gamma-ray detectors. The {sup 16}O(n,p){sup 16}N, {sup 37}Cl(n,p){sup 37}S and {sup 89}Y(n,n{prime}){sup 89m}Y activation reactions served as dosimeters.

 
 
 
 
201

Application of electron energy loss spectroscopy to microanalysis of irradiated stainless steels  

Energy dispersive X-ray spectroscopy (EDXS) has limited application to microanalysis of radioactive materials because of degraded detector performance and the intrinsic'' spectrum associated with the radioactive decay. Electron energy loss spectroscopy (EELS) is not affected by specimen radioactivity and also offers the possibility of improved spatial resolution. Measurements of radiation-induced segregation (RIS) in irradiated stainless steels have been made by both techniques. Analytical electron microscopy was performed at 100 kV in a Philips EM400T/FEG, equipped with an EDAX 9100/70 EDXS system and a Gatan 666 parallel detection EELS (PEELS). Microanalysis was performed in the STEM mode (<2-nm-diam probe with >0.5 nA) with the same acquisition time (50 s) used for both techniques.

202

Shielding calculations at dismantled synchrocyclotron  

The Space Radiation Effects Laboratory located in Newport News, Virginia, was operated by the College of William and Mary for the National Aeronautics and Space Administration. A synchrocyclotron which was formerly in operation in this building was removed in 1980. At several locations, the scattered radiation caused an induced radioactivity within the walls of the cyclotron room. A radiological survey has been performed to determine the amount of residual radioactivity on the walls. Calculations were performed to determine the thickness of the concrete walls and floor for shielding the residual radiation in the cyclotron room. Recommendations are made to minimize exposures from the residual radioactivity on the walls and floor of the cyclotron room to potential occupants working in the building. 19 refs., 1 fig., 2 tabs.

203

Blood pH and brain uptake of /sup 14/C-morphine  

/sup 14/C-Morphine was injected iv in control awake rats or in rats subjected to metabolic alkalosis or acidosis. Ten minutes later, radioactivity was determined within each of seven brain regions, after correction was made for intravascular tracer. In each region, parenchymal radioactivity was correlated positively and significantly (P less than 0.05) with arterial blood pH. Brain radioactivity was twofold to threefold greater in alkalotic rats (mean pH . 7.62) than in acidotic rats (mean pH . 7.16). The results are consistent with the pH-partition hypothesis for drug entry into the brain and indicate that morphine uptake can be increased by elevating the fraction of lipid-soluble uncharged morphine base in blood, by means of alkalosis. The observations may account for an exaggerated morphine-induced analgesia in alkalotic patients.

204

Nuclear Astrophysics  

Nuclear physics has a long and productive history of application to astrophysics which continues today. Advances in the accuracy and breadth of astrophysical data and theory drive the need for better experimental and theoretical understanding of the underlying nuclear physics. This paper will review some of the scenarios where nuclear physics plays an important role, including Big Bang Nucleosynthesis, neutrino production by our sun, nucleosynthesis in novae, the creation of elements heavier than iron, and neutron stars. Big-bang nucleosynthesis is concerned with the formation of elements with A <= 7 in the early Universe; the primary nuclear physics inputs required are few-nucleon reaction cross sections. The nucleosynthesis of heavier elements involves a variety of proton-, alpha-, neutron-, and photon-induced reactions, coupled with radioactive decay. The advent of radioactive ion beam facilities has opened an important new avenue for studying these processes, as many involve radioactive species. Nuclea...

205

LRT 2006: 2. topical workshop in low radioactivity techniques  

This second topical workshop in low radioactivity techniques is intended to bring together experts in the field of low background techniques, especially applied to dark matter experiments, double beta decay experiments and neutrino detection in underground laboratories. This workshop has been organized into 7 sessions: 1) underground facilities (where a worldwide review is made), 2) neutron and muon induced background, isotope production, 3) low background counting techniques and low background detectors, 4) techniques for radon reduction, purified noble gases and liquid scintillator purification, 5) low levels on Pb-Bi-Po{sup 210} and surface background, 6) low radioactivity detector components and material purification, and 7) low radioactive techniques in other applications (particularly to check the geographical origin of food-products or to date wine. This document is made up of the slides of the presentations.

206

Localization of volatile isotopes on a cryotrap  

Neutron-induced fission of uranium allows for the production of high-intensity neutron-rich radioactive ion beams. However, also large quantities of unwanted volatile radioactive species are produced that have to be hindered from contaminating the beamline and vacuum system of the facility. In the framework of radioprotection studies within the MAFF project at the FRM II in Garching with 1014fission events/s [D. Habs et al., The Munich accelerator for fission fragments MAFF, Nucl. Instr. and Meth. B 204 (2003) 739], the performance of a cryotrap system has been studied, designed to localize gaseous radioactivity close to its origin. These studies provide important radioprotection information for the planned EURISOL facility with 1015fission events/s. Design considerations of a compact cryo...

207

Radioecological impact of Saharan dusts fallout. Case study of a major event on the 21. of february 2004 in south part of France; Impact radioecologique des retombees de poussieres sahariennes. Episode majeur du 21/02/2004 dans le sud de la France  

Lithometeors, Sirocco or more commonly 'red mud' are all in fact related to a single phenomenon which affects France every year: the wind transport and deposit of desert particles from the Sahara. On the 21. of February 2004, the southern part of France is swept by a weather event of wind transport of Saharan particles. The recordings of atmospheric dust contamination and the deposit of dust, which results from it, make an episode of exceptional width. In a few hours, the thickness of the deposit exceeds 1 mm (up to 4 mm in Corsica) with a maximum density of surface charge of 50 g.m{sup -2} (50 tons per km{sup 2}). The loads of the PM{sub 10} type particles in the air, recorded by associations of monitoring of the quality of the air, indicate concentrations multiplied to the maximum by 10 and an influence on the ground of the plume ranging between 300 000 and 350 000 km{sup 2}. To the end, 2 million tons are deposited on a portion of the territory located at the south of a line from Nantes to Besancon. This event also had a significant radio-ecological impact, leading to significant {sup 137}Cs, {sup (239+240)}Pu, {sup 241}Am, activity levels of 38 Bq. kg{sup -1} sec, 1 Bq. kg{sup -1} sec and 0,46 Bq. kg{sup -1} sec, respectively. Quality of air monitoring organisations recorded 10-fold increases in the concentration of charged PM{sub 10} {sup 2}type particles within the cloud; ground coverage stretched over a 300 000 km{sup 2} surface area. Across this whole area, the artificial radioactivity deposits are estimated to 37.10{sup 10} Bq. In term of flow of deposit, this episode represents, with him only, i.e. in a few hours, a {sup 137}Cs deposition equivalent to that recorded on average in a cumulated time of one year. Data from this study show that these weather-climatic episodes generate today, environmental samples which on average, present the highest levels and flux of artificial radioactivities, more than those in the sediments of the Rhone river deposited by flood events, for example. Changes in artificial radionuclide activity levels in the atmospheric area close to ground level are routinely attributed to resuspension of formerly deposited aerosols. In the particular case of the Saharan dust deposits, apart from the resuspension mechanisms that caused the Saharan soil particles to be taken up, other mechanisms may have intervened during transports up until deposit on French soil. Such mechanisms, which have already been identified for other atmospheric compounds or pollutants, give a lead in attempting to understand the enhanced relative or absolute radioactivity of the mineral particles. Two hypotheses have been put forward to explain this enhanced radioactivity: either a process rather like a 'horizontal leaching' of compounds or pollutants present in the atmosphere during transport, or the early fall of the heavier and thus less radioactive mineral particles, giving rise to a relative increase in specific activity. One cannot overlook the contribution these sporadic phenomena make to atmospheric deposits on an annual basis. Further studies are needed to evaluate the weight of these phenomena on a multi-annual scale in the reduction of activity levels in the atmospheric compartment by dry or wet process and at short time scale the deposition of radioactivity with dust from remote regions. Taking into account current metrological performance devices at the IRSN (Institute for Radiological Protection and Nuclear Safety), regular monitoring of these events allow opportunity to follow the changes of plutonium isotopes in the atmosphere. (authors)

208

The use of artificial neural networks in PVT-based radiation portal monitors  

Polyvinyl toluene (PVT)-based gamma-ray scintillation detectors are cost effective for use in radiation portal monitors (RPMs) applied to screening for illicit radioactive materials at international border crossings. While such systems can provide good sensitivity for detecting the presence of radioactive materials, they have poor spectral resolution that limits their ability to identify the isotopic content of the source of radiation. Without use of spectral information, RPMs cannot distinguish innocent materials that contain low levels of normally occurring radioactive materials (NORM) from special nuclear materials of concern. Thus, to reduce the number of “nuisance” alarms produced in PVT-based RPMs by innocent materials, algorithms that analyze spectra from PVT detectors must be optimized to make use of the limited information contained in their energy spectra. This paper reports the first application of artificial neural networks (ANNs) in such an analysis. This work was performed as a feasibility study whose primary objective was to describe how an ANN-based alarm algorithm can be used to reduce the nuisance/false alarm probability while maintaining high-detection probabilities for radioactive sources of interest. The spectra used in this study were obtained from a limited set of actual PVT-based RPM data, and included cases where simulated spectra were inserted into the measured spectra. This paper also includes an analysis of spectral channel importance and shows evaluations of two methods used to reduce the initial set of energy spectra channels into smaller sets. Although not a comprehensive study, the results of this work show that it is possible to use ANNs successfully to discriminate NORM from other materials for realistic PVT-based RPM spectra. The algorithms described may also have potential application in the analysis of sodium iodide based RPM spectra.

209

Status of radioactivity monitoring in French Polynesia in 2010 and follow up of the Fukushima accident impact in French Polynesia and New Caledonia from March to May 2011; Bilan de la surveillance de la radioactivite en Polynesie francaise en 2010 et suivi de l'impact de l'accident de Fukushima en Polynesie francaise et Nouvelle-Caledonie de mars a mai 2011  

Radiological monitoring of the French environment is one of IRSN's permanent tasks as part of public policy on nuclear safety and radiological protection. It is helping to guarantee the best possible protection of the population. Exercised in Polynesia since 1962, this monitoring, which takes place on seven islands (Tahiti, Maupiti, Hao, Rangiroa, Hiva Oa, Mangareva and Tubuai) representing the five archipelagos, consists of taking regular samples of various kinds from the different environmental compartments (air, water, soil, food..) with which the population may be in contact. Regarding food, the samples analyzed are representative of the diet of Polynesians living in the five archipelagos of that territory, and from the marine environment of the open sea, marine and terrestrial lagoon. Almost all samples are measured at the Laboratory for the Study and Monitoring of the Environment IRSN, based in Vairao on the island of Tahiti. During the year 2010 results fall under the continuity of a regular reduction of the levels of radioactivity since the stop, in 1974, of the French atmospheric tests. This residual radioactivity relates to primarily the {sup 137}Cs. In term of additional dose, this artificial and residual radioactivity is lower than 5 {mu}Sv.y{sup -1} (5 micro-Sieverts per year). This value corresponds to less than 0,5 % of exposure due to natural radioactivity in Polynesia (approximately 1 000 {mu}Sv.y{sup -1}). This 2010 report also includes the special monitoring engaged during spring 2011 to evaluate a possible radiological impact in French Polynesia and New-Caledonia territories due to the nuclear accident of Fukushima that occurred on March 11, 2011 (see chapter 5). (authors)

210

Topology and shape optimization of induced-charge electro-osmotic micropumps  

For a dielectric solid surrounded by an electrolyte and positioned inside an externally biased parallel-plate capacitor, we study numerically how the resulting induced-charge electro-osmotic (ICEO) flow depends on the topology and shape of the dielectric solid. In particular, we extend existing conventional electrokinetic models with an artificial design field to describe the transition from the liquid electrolyte to the solid dielectric. Using this design field, we have succeeded in applying the method of topology optimization to find system geometries with non-trivial topologies that maximize the net induced electro-osmotic flow rate through the electrolytic capacitor in the direction parallel to the capacitor plates. Once found, the performance of the topology-optimized geometries has been validated by transferring them to conventional electrokinetic models not relying on the artificial design field. Our results show the importance of the topology and shape of the dielectric solid in ICEO systems and point to new designs of ICEO micropumps with significantly improved performance.

211

Engineering Polarization Rotation in a Ferroelectric Superlattice  

A key property that drives research in ferroelectric perovskite oxides is their strong piezoelectric response in which an electric field is induced by an applied strain, and vice versa for the converse piezoelectric effect. We have achieved an experimental enhancement of the piezoelectric response and dielectric tunability in artificially layered epitaxial PbTiO3/CaTiO3 superlattices through an engineered rotation of the polarization direction. As the relative layer thicknesses within the superlattice were changed from sample to sample we found evidence for polarization rotation in multiple x-ray diffraction measurements. Associated changes in functional properties were seen in electrical measurements and piezoforce microscopy. The results demonstrate a new approach to inducing polarization rotation under ambient conditions in an artificially layered thin film.

212

The effect of infiltration induced crack closure on crack growth retardation  

It is now well known that extra materials on the flanks of a fatigue crack will cause premature crack closure and a reduction in crack growth rate. These extra materials may be residual plastic wake, corrosion/oxidation products, phase transformation and fluid. Micro-roughness of the fatigue fracture surface is also capable of bringing about premature crack closure. The phenomenon of crack growth retardation following a single tensile overload has been attributed to some of these crack closure mechanisms. Considerable amount of research has been carried out on the mechanisms and effects of naturally occurring crack closure on fatigue crack growth. By contrast, relatively little attention has been given to artificially induced crack closure. Recently, it has been noted that artificially created crack closure may lead to the development of practical fatigue crack repair methods. This work presents the preliminary results on the effects of using alumina powder reinforced epoxy resin infiltration to induce crack closure.

213

Distribution of convective energy at upper level in South Korea and the possibility of artificial showery rain caused by activated CAPE  

This paper reports a theoretical study on the possibility of inducing artificial showery rain using the convective available potential energy, which is naturally stored in the troposphere. We calculated the environmental parameters (frequency of climatic values, extreme value of stability index, etc.) in the upper troposphere using rawinsonde data from six main stations in Korea from 2001 to 2008 and examined the temporal spatial convective energy according to region. Our results showed that convective available potential energy, which can induce artificial rainfall, existed in the troposphere mainly in summer and were low in other seasons. Its value was found to be highest during late afternoon and in inland regions. We examined the vertical structure of the atmosphere using moisture conv...

214

Numerical Simulations of Weak Lensing Measurements  

(Abridged) Weak gravitational lensing induces distortions on the images of background galaxies, and thus provides a direct measure of mass fluctuations in the universe. Since the distortions induced by lensing on the images of background galaxies are only of a few percent, a reliable measurement demands very accurate galaxy shape estimation and a careful treatment of systematic effects. Here, we present a study of a shear measurement method using detailed simulations of artificial images. The images are produced using realisations of a galaxy ensemble drawn from the HST Groth strip. We consider realistic observational effects including atmospheric seeing, PSF anisotropy and pixelisation, incorporated in a manner to reproduce actual observations with the William Herschel Telescope. By applying an artificial shear to the simulated images, we test the shear measurement method proposed by Kaiser, Squires & Broadhurst (1995, KSB). Overall, we find the KSB method to be reliable with several provisos. To guide f...

215

Topology and shape optimization of induced-charge electro-osmotic micropumps  

For a dielectric solid surrounded by an electrolyte and positioned inside an externally biased parallel-plate capacitor, we study numerically how the resulting induced-charge electro-osmotic (ICEO) flow depends on the topology and shape of the dielectric solid. In particular, we extend existing conventional electrokinetic models with an artificial design field to describe the transition from the liquid electrolyte to the solid dielectric. Using this design field, we have succeeded in applying the method of topology optimization to find system geometries with non-trivial topologies that maximize the net induced electro-osmotic flow rate through the electrolytic capacitor in the direction parallel to the capacitor plates. Once found, the performance of the topology-optimized geometries has been validated by transferring them to conventional electrokinetic models not relying on the artificial design field. Our results show the importance of the topology and shape of the dielectric solid in ICEO systems and pointto new designs of ICEO micropumps with significantly improved performance.

216

Status of JAEA KEK radioactive ion beam facility, TRIAC  

In collaboration with Japan Atomic Energy Agency (JAEA) and High Energy Accelerator Research Organization (KEK), we have been constructed an ISOL-based radioactive ion beam facility, Tokai Radioactive Ion Accelerator Complex (TRIAC), at JAEA Tokai. This facility consists of a Charge-Breeding 18 GHz Electron Cyclotron Resonance Ion-Source (CB-ECRIS), the Split-Coaxial Radio-Frequency Quadrupole (SCRFQ)- and Interdigital-H (IH)-type linacs. An Isotope Separator On-line (JAEA ISOL) is connected to the CB-ECRIS as the injector of radioactive ions which are produced in proton-induced fission of uranium and heavy-ion reaction. The primary beams are provided from the JAEA Tandem Accelerator. Radioactive singly-charged ions from the JAEA ISOL are bred to q/A ? 1/7 in the CB-ECRIS and then multi-charged ions are accelerated with the linac-complex from 2 keV/u to the energy between 0.14 and 1.1 MeV/u. So far, we successfully accelerate 8Li+ and 138Xe20+, the acceleration energy of 1.1 MeV/u was achieved. From October 2005, some radioactive ion beams of 1.1 MeV/u have become available for users.

217

Radioactive particles after different nuclear events in the USSR (overview and modern data)  

Institute of Global Climate and Ecology participated in all stages of investigations concerning spreading of the radioactive particles formed after nuclear explosions. Since 1963 the radioactive particles from the surface nuclear explosions on the Semipalatinsk Test Site were investigated. Since 1964 the study of the environmental contamination from the underground nuclear explosions (including the cratering nuclear explosions) was carried out. Simultaneously the secondary radioactive aerosols released into the atmosphere from ventilated underground explosions were investigated. Since 1986 the forming and spreading of the radioactive aerosols from Chernobyl accident was studied. An overview of retrospective data will be presented. For example, the fragmentation radionuclides {sup 90}Sr, {sup 137}Cs and {sup 155}Eu, radionuclides induced by neutrons {sup 60}Co, {sup 152}Eu, {sup 154}Eu and transuranium radionuclides {sup 238}Pu, {sup 239+240}Pu and {sup 241}Am were estimated in 15 particles of August, 29, 1949 explosion using the semiconductor spectrometry and radiochemical analysis. Data collection include the samples taken on local traces of ground and underground excavation nuclear explosions, this information will be added by the modern data from soil samples near '1004' explosion (lake Chagan), October 2003. The results of comparison of radionuclide fractionation in the radioactive particles in slag from cratering nuclear explosions and in melt samples will be presented. Main results obtained under the IAEA Research Contract no. 11468. (author)

218

Tissue localization of the carcinogenic glutamic acid pyrolysis product Glu-P-1 in control and beta-naphthoflavone-treated mice and rats  

Autoradiograms obtained after i.v. injection of the {sup 14}C-labelled carcinogenic glutamic acid pyrolysis product Glu-P-1 to mice and rats showed a pronounced uptake of radioactivity in the liver, kidney, thyroid and nasal mucosa. High concentrations of radioactivity were present in the bile and intestinal contents at short post-injection times. In the male rat, the Zymbal's gland and the preputial gland were identified as sites of high and specific binding at all post-injection times examined. The liver and nasal mucosa were identified as sites of retention of non-extractable radioactivity. In the pigmented mouse, Glu-P-1 and/or its metabolites were accumulated in melanin. Glu-P-1 is known to be activated by cytochrome P-448. Pretreatment with beta-naphthoflavone (a cytochrome P-448 inducer) did not change the tissue localization of radioactivity in either species except for the liver where the overall labelling was decreased. Neither did pretreatment of mice with the glutathione-depleting agent phorone change the distribution pattern significantly. However, combined pretreatments of mice with either phorone or beta-naphthoflavone and the cytochrome P-448 inhibitor 9-hydroxyellipticine resulted in an increased overall retention of radioactivity in the body.

219

High Density Adsorption of Porphyrins onto Clay Layer without Aggregation: Characterization of Smectite-Cationic Porphyrin Complex  

Adsorption of the +4 charged cationic porphyrins onto an artificially synthesized smectite was studied. Porphyrin molecules adsorb on the clay sheet with high density to neutralize all the minus charges of the clay surface without aggregation by a novel method of a size-matching of distances between the charge sites. An efficient energy transfer between different porphyrins was induced on the clay surface, while there was no interaction in the ground state.   

220

Kinetics and stability of the mixing flow patterns found in champagne glasses as determined by laser tomography techniques: likely impact on champagne tasting  

Laser tomography techniques were used in order to make visible the flow patterns induced by ascending bubbles in flutes poured with champagne. The stability of flow patterns was investigated in flutes showing natural (without any specific surface treatment) as well as artificial effervescence (i.e., engraved at their bottom), all along the first 15min after pouring. Engravement conditions were found to strongly influence the kinetics and the stability with time of the mixing flow phenomena found in champagne glasses.

 
 
 
 
221

Several- and Many-Electron Artificial-Atoms at Filling Factors between 2 and 1  

We introduce new phenomena that can be studied in an artificial-atom vertical single electron transistor. As we move from the few-electron regime to the several-electron regime, and then the many-electron regime, features in the conductance peaks related to magnetic field induced spin polarization evolve. This allows us to probe the spin-flip region bounded by the last single-particle crossing at low field, and the eventual formation of a maximum density droplet at high field.   

222

Laser-induced Mist and Particle Formation from Ambient Air: A Possible New Cloud Seeding Method  

A new method of water condensation is reported. A UV laser induces seed formation from the air itself for water mist or ice particles depending on the temperature of the ambient air. The possible mechanism of this new phenomenon is proposed with photochemical radical formation and following reactions. This may offer the new prospect of a simple and environmentally harmless way to create artificial rain and snow.   

223

SigM-responsive genes of Bacillus subtilis and their promoters.  

Promoters of nine Bacillus subtilis genes (bcrC, yacK, ydaH, yfnI, yjbD, ypbG, ypuA, yraA, and ysxA), all responsive to artificially induced increases in the stress-responsive extracytoplasmic function sigma factor, SigM, were mapped by rapid amplification of cDNA ends-PCR. The resulting promoter consensus suggests that overlapping control by SigX or SigW is common. PMID:17434969

224

SigM-Responsive Genes of Bacillus subtilis and Their Promoters?  

Promoters of nine Bacillus subtilis genes (bcrC, yacK, ydaH, yfnI, yjbD, ypbG, ypuA, yraA, and ysxA), all responsive to artificially induced increases in the stress-responsive extracytoplasmic function sigma factor, SigM, were mapped by rapid amplification of cDNA ends-PCR. The resulting promoter consensus suggests that overlapping control by SigX or SigW is common.

225

Monitoring of Reinforced Concrete Corrosion and Deterioration by Periodic Multi-Sensor Non-Destructive Evaluation  

The paper showcases a collaborative benchmark project evaluating NDE methods for deterioration monitoring of laboratory bridge decks. The focus of this effort is to design and build concrete test specimens, artificially induce and monitor corrosion, periodically perform multi-sensor NDE inspections, followed by 3D imaging and destructive validations. NDE methods used include ultrasonic echo array, ground penetrating radar (GPR), active infrared thermography with induction heating, and time-resolved thermography with induction heating.

226

Technical Strategies to Improve Tissue Engineering of Cartilage-Carrier-Constructs  

Technical aspects play an important role in tissue engineering. Especially an improved design of bioreactors is crucial for cultivation of artificial three-dimensional tissues in vitro. Here formation of cartilage-carrier-constructs is used to demonstrate that the quality of the tissue can be significantly improved by using optimized culture conditions (oxygen concentration, growth factor combination) as well as special bioreactor techniques to induce fluid-dynamic, hydrostatic or mechanical load during generation of cartilage.

227

The Enlightened Game of Life  

We investigate a special class of cellular automata evolving in a environment filled by an electromagnetic wave. The rules of the Conway's Game of Life are modified to account for the ability to retrieve life-sustenance from the field energy. Light-induced self-structuring and self-healing abilities and various dynamic phases are displayed by the CA. Applications are envisaged in evolutionary biology, artificial life, DNA replication, swarming, optical tweezing and field-driven soft-matter.

228

Structure transformations of endocrine system organs during adaptation to increased radioactivity  

It is well known that during ecological monitoring of contaminated territories registration of early abnormalities in an organism is hampered by man-caused influence of habitat. Under these circumstances study of both structural and functional changes in organs and tissues of rodents inhabiting radioactive contaminated territories is of great importance. Study of structural features of endocrine glands, hormones of which trigger the process of active adaptive changes in an organism, is very important in radioecological surveys. Basing on long-term study of voles we have determined that long-term living by rodents on the territories characterized by increased natural and artificial radioactivity (radium contaminated fields in the Komi Republic and 30-km zone of Chernobyl APS) substantially influences morpho-functional state of endocrine system organs, causing quantitative and qualitative changes. It is demonstrated that population processes modify biological consequences of small doze chronic ionizing radiation in habitat. We noticed the following: high heterogeneity of histological changes of thyroid gland and adrenal gland as a response to radioactive habitat contamination; disorder of interconnection among different links of endocrine system; dependence of radiation effects on gender, age, degree and character of radiation contamination of a habitat as well as duration of radioactive influence. We have got data on morphological characteristics of thyroid gland and adrenal gland during different phases of population amount of this kind of rodents. It was discovered that effectiveness of radiation influence is not the same during different periods of population cycle. Presence of voles on the territories characterized by increased radioactivity causes chronic tension of adrenal cortex (increasing of the organ mass, enlarging of thickness of zona fasciculata and zona reticularis). Destructive-necrotic processes combine with manifestation of reparative regeneration. This is best marked during peak of population amount. There are histo-functional changes in the thyroid gland with hypofunction sign: enlarging.of follicles and flattering of thyroid epithelium cells, colloid uptake and induration, proliferation of follicular epithelium into follicle lumen. We determined that more considerable structural abnormalities in endocrine system organs are discovered during their high functional activity influenced by radiation exposure. Set of morphological changes of thyroid gland tissue and adrenal cortex among voles from radioactive contaminated territories on one hand, plays significant role in adaptation, enabling organism to cope (to some extent) with negative radiation effect, on the other hand shows signs of premature ageing and is a basis for pathological abnormalities. (author)

229

Decision-Making Risks Concerning the Construction of the Goiania Waste Repository  

As it is well known, an accident with a teletherapy source made of {sup 137}CsCl with an initial activity of 59 TBq occurred in Goiania, in September of 1987. This paper will discuss the decision-making process, and the struggle that followed the decision to build the final repository for the remnants of the Goiania accident. The Goiania final repository was built as planned. The two subsurface structures under the grassy artificial hills hold the overall volume of the remnants of the Goiania accident. The near hill holds 5x10{sup 3} m3 of stabilized wastes without radioactivity, or with very low radioactivity. The far hill holds the remaining 6.5x10{sup 3} m{sup 3} of stabilized wastes with low and medium radioactivity. The central part of each subsurface hill has been shielded by wastes with less and less radioactivity. The overall fenced area occupies 1.85x10{sup 5} m{sup 2}. The external radiation levels are similar to the surrounding background, and much lower than those found in the Brazilian areas of high natural radioactivity. The site is permanently monitored by independent institutions, including Brazilian universities, and national and international organizations. As it was mentioned earlier, the final repository was build to last for at least 400 years. Although the initial decision to adopt a too conservative decontamination criterion in the case of the Goiania accident was bound to produce excessive amount of waste; such decision proved, retrospectively, not to be bad because the excess low radioactive waste produced was used as extra shielding material in final repository. The technical decision-maker should not abandon risk estimates, but should be aware that credibility is the main basis to achieve acceptability of a decision by the general public. Risk perception should be regarded as only a first step towards what may be called knowledge, or comprehension of risk estimates, but risk perception by the general public is still an open issue. The problem of a fixed, or near fixed risk coefficient applied to repositories needs to be further addressed, because it is in essence a translation of the LNT hypothesis. The decision to make the final repository for the remnants of the Goiania accident was a successful one, but one has to take into proper consideration, at least retrospectively, that the decision-making process was facilitated because the problem of Goiania was much simpler than the case of a repository for LLRW in general.

230

The radioactive ion beam production systems for the SPIRAL2 project.  

The SPIRAL2 project, currently under construction at GANIL, will include an isotope separator on line based facility for the production and acceleration of radioactive ion beams. A superconducting linear accelerator will accelerate 5 mA deuterons up to 40 MeV and 1 mA heavy ions up to 14.5 MeV/u. These primary beams will be used to bombard both thick and thin targets. We are investigating three different techniques to produce the radioactive ion beams: (1) the neutron induced fission of uranium carbide, (2) the direct interaction of deuterons in a uranium carbide target, and (3) the interaction of a heavy ion beam with a target. All these production systems will be coupled to an ion source. Four kinds of ion sources are foreseen for the ionization of the radioactive atoms: an electron cyclotron resonance ion source, a surface ionization ion source, a forced electron beam induced arc discharge ion source, and a laser ion source depending on the characteristics of the desired radioactive ion beam in terms of intensity, efficiency, purity, etc. A presentation of the SPIRAL2 project and of the different production systems is given. PMID:18315162

231

Radiologic assessment of a self-shield with boron-containing water for a compact medical cyclotron.  

The cyclotron at our hospital has a self-shield of boron-containing water. The amount of induced radioactivity in the boron-containing water shield of a compact medical cyclotron has not yet been reported. In this study, we measured the photon and neutron dose rates outside the self-shield during cyclotron operation. We estimated the induced radioactivities of the boron-containing water used for the self-shield and then measured them. We estimated the activation of concrete outside the self-shield in the cyclotron laboratory. The thermal neutron flux during cyclotron operation was estimated to be 4.72 × 10(2) cm(-2) s(-1), and the activation of concrete in a cyclotron laboratory was about three orders of magnitude lower than the clearance level of RS-G-1.7 (IAEA). The activity concentration of the boron-containing water did not exceed the concentration limit for radioactive isotopes in drainage in Japan and the exemption level for Basic Safety Standards. Consequently, the boron-containing water is treatable as non-radioactive waste. Neutrons were effectively shielded by the self-shield during cyclotron operation. PMID:22370731

232

The anaerobic corrosion of carbon steel and cast iron in artificial groundwaters  

In Sweden, high level radioactive waste will be disposed of in a canister with a copper outer and a cast iron or carbon steel inner. If the iron insert comes into contact with anoxic geological water, anaerobic corrosion leading to the generation of hydrogen will occur. This paper presents a study of the anaerobic corrosion of carbon steel and cast iron in artificial Swedish granitic groundwaters. Electrochemical methods and gas collection techniques were used to assess the mechanisms and rates of corrosion and the associated hydrogen gas production over a range of conditions. The corrosion rate is high initially but is anodically limited by the slow formation of a duplex magnetite film. The effects of key environmental parameters such as temperature and ionic strength on the anaerobic corrosion rate are discussed.

233

Release of uranium and thorium from monazite ores: implications for phosphatic wasteforms  

Monazite is an important economic source of uranium, thorium, and the rare earth elements. Economically viable concentrations occur in placer deposits and as massive ore bodies in igneous and metamorphic provinces throughout the world. This and its refractory nature has led to speculation that artificial phosphate-based matrices similar in composition to monazite may prove useful as wasteforms for high level radioactive waste. Before a detailed evaluation can be made, however, it is worthwhile to assess the long term degradation behaviour of natural monazites in diverse hydrogeochemical environments. This paper focusses on the Steenkampskraal monazite mine, South Africa and compares findings with those from monazite occurrences in the Palaeozoic rocks of Britain and Western France. In all cases where the monazite has altered, a marked fractionation of the lanthanide series elements is apparent, together with substantial redistribution of uranium and thorium. The implications for waste encapsulation are discussed in terms of the potential for groundwater transport away from the source. (orig.)

234

Study on the dynamics of halogen elements in the agro-environment and these element`s deficiency, toxicity and environmental hazards by the application of the neutron activation analysis method  

A neutron activation analysis method is an accurate and highly sensitive method for analyzing halogen elements (iodine, bromine and chlorine) except fluorine. It is unsubstitutable and valuable method especially for iodine (including radioactive {sup 129}I) and bromine which are present at lower levels. Halogen elements have high chemical and physiological activities and move widely in the environment. As a result, deficiency and an excess of halogen elements in plants and animals have occurred and artificial halogen compounds have caused environmental pollution in wide areas. We efficiently utilized the neutron activation analysis method and an activable tracer method to obtain valuable findings which contribute to the clarification of and measures against these actual problems and which are also concerned with the occurrence, distribution and migration of halogen elements in the environment, especially agricultural and forestry ecosystems in space and in time. (author)

235

Radiation Protection Research: Radioecology  

The objectives of SCK-CEN's Radioecology programme are (1) to evaluate, based on laboratory and field experiments, the mechanisms and dynamic (fluxes) of radionuclide transfers in the biosphere, considering all factors affecting the transfer parameters and their variability; (2) to develop and optimise models to predict the fate of radionuclides in the biosphere; (3) to advise on appropriate countermeasures and remediation options to reduce public exposure to artificial and man-enhanced natural radioactivity and to evaluate their feasibility, cost effectiveness and sustainable character; (4) to provide information to national and international authorities to enable these to assess the consequences of routine and accidental releases for populations and to select the most adequate mitigation actions. Main achievements in 1999 are reported.

236

Long-term tagging of elvers, Anguilla anguilla, with radioactive europium  

Elvers were labeled with 152Eu and 155Eu. Optimum conditions turned out to be incubation for 3 h at 15.degree. C in artificial sea water containing 2% NaCl and 0.1% KCl, EuCl3 at 1 mCi (37 MBq) l-1 and an eel concentration of about 15%. Laboratory experiments pointed to a biological half-life of added europium of 1.6 .+-. 0.5 years. Thirteen hundred 155Eu-labelled elvers (50 Bq per eel), each weighing on average 0.21 g, were set out near Oskarshamn on the east coast of Sweden in June 1982. Three of these were caught nearby in May 1985 and one was caught in August 1985. They weighed then on average 56 g and showed no significant loss of label other than the physical half-life (5.1 years). All the radioactivity was found in bone tissue.

237

A new NaI(Tl) four-detector layout for field contamination assessment using artificial neural networks and the Monte Carlo method for system calibration  

An NaI(Tl) multidetector layout combined with the use of Monte Carlo (MC) calculations and artificial neural networks(ANN) is proposed to assess the radioactive contamination of urban and semi-urban environment surfaces. A very simple urban environment like a model street composed of a wall on either side and the ground surface was the study case. A layout of four NaI(Tl) detectors was used, and the data corresponding to the response of the detectors were obtained by the Monte Carlo method. Two additional data sets with random values for the contamination and for detectors’ response were also produced to test the ANNs. For this work, 18 feedforward topologies with backpropagation learning algorithm ANNs were chosen and trained. The results showed that some trained ANNs were able to...

238

Workers' radioprotection: professional exposure to ionizing radiation in France: assessment for 2010; La radioprotection des travailleurs. Exposition professionnelle aux rayonnements ionisants en France: bilan 2010  

As more than 300.000 workers are potentially exposed to different artificial sources of ionizing radiation in different activity sectors in France (nuclear, industry, research, and medicine) and some others to natural radiation sources, this report proposes an assessment of these exposures for 2010. The report describes the monitoring of professional exposure (legal framework, monitoring modalities, means and actions of the IRSN), presents the methodology adopted for this annual assessment of workers' exposure to ionizing radiation. It gives this assessment for civilian activities submitted to an authorization or declaration regime and for defence activities (general results for external and internal exposures, exposure in the medical and veterinary sector, in the nuclear sector, in the industrial sector, in the research sector). It finally addresses the exposure of workers to natural radioactivity

239

The Discovery of Artificial Radioactivity  

We reconstruct Fr?d?ric Joliot and Ir?ne Curie?s discovery of artificial radioactivity in January 1934 based in part on documents preserved in the Joliot?Curie Archives in Paris, France. We argue that their discovery followed from the convergence of two parallel lines of research, on the neutron and on the positron, that were focused on a well-defined experimental problem, the nuclear transmutation of aluminum and other light elements. We suggest that a key role was played by a suggestion that Francis Perrin made at the seventh Solvay Conference at the end of October 1933, that the alpha-particle bombardment of aluminum produces an intermediate unstable isotope of phosphorus, which then decays by positron emission. We also suggest that a further idea that Perrin published in December 1933,...

240

Radioecology  

The objectives of SCK-CEN's Radioecology programme are: (1) to evaluate, based on laboratory and field experiments, the mechanisms and dynamic (fluxes) of radionuclide transfers in the biosphere, considering all factors affecting the transfer parameters and their variability; (2) to advise on appropriate countermeasures and remediation options to reduce public exposure to artificial and man-enhanced natural radioactivity and to evaluate their feasibility, cost effectiveness and sustainable character; (3) to provide information to national and international authorities to enable these to assess the consequences of routine and accidental releases for populations and to select the most adequate mitigation actions; (4) to educate professionals, students and the public on different aspects of radioecology through lectures, conferences and brochures. Main achievements in 1997 are reported.

 
 
 
 
241

Fermi: a physicist in the upheaval; Fermi: un physicien dans la tourmente  

This book summarizes the life, works and complex personality of the Italian physicist Enrico Fermi (1901-1954) whose myth is linked with the political upheaval of the 2. world war: the youth of an autodidact, the theorician and the quantum mechanics, his invention of a quantum statistics, the weak interaction theory, his works on artificial radioactivity, the end of the Fermi team and his exile in the USA, the secrete researches at the university of Columbia and the birth of the first atomic 'pile' (December 2, 1942), the building of Los Alamos center and the Alamogordo explosion test, the disagreements among the physicists of the Manhattan project and the position of Fermi, Fermi's contribution in the H-bomb construction, the creation of the physics school of Chicago, the Oppenheimer spying affair. (J.S.)

242

Natural decrease of the intensity level of artificial radioactive isotopes in the Barents Sea  

The results of radioecological investigations carried out within the framework of the Russian-Finnish high-latitude expedition in 2007 are presented. The characteristics of the present-day accumulation level of the significant radioecological isotopes 137Cs, 90Sr and 239,240Pu in the Barents Sea are described. The comparative analysis is performed for the radiation pollution of the environment in the 1980s and 1990s and in the first decade of the 21st century. Natural purification processes in the marine environment are the main factors of the decrease in the intensity level of artificial radioactive isotopes. These processes include repeated dilution, nuclear decay, occlusion by sediments and suspended solid material, and accumulation by aquatic inhabitants. A stable decreasing trend is o...

243

LIMITATIONS OF THE USE OF RADIATION FOR DIAGNOSTIC AND ENDOCRINE THERAPEUTIC PURPOSES IN GYNECOLOGY AND OBSTETRICS  

A comprehensive review deals with human responses to all sources of radiation, both natural and artificial. The rise in radioactive contaminants of air, water, and food is discussed. Emphasis is placed on data concerning the effects on genetic factors, in the general population, of the increased use of ionizing radiation, principally in the form of x rays. The use of radiation therapeutically in gynecology and obstetrics is discussed. It is concluded that in humans the immediate effects do not confirm geneticists' predictions. It is suggested that there has been an excessive tendency to extrapolate to the human, without due caution, results obtained in experiments with rats and fruit flies. It is pointed out also that in animal experiments, the same amount of radiation can produce different effects depending on how it is applied. It is concluded that the cautious use of radiation by qualified medical practitioners entails relatively low risk of somatic, and especially genetic, injury to humans. (BBB)

244

Effects of anabolic androgenic steroids on chylomicron metabolism  

ObjectiveTo evaluate the effects of anabolic androgenic steroids (AAS) on chylomicron metabolism. MethodsAn artificial lipid emulsion labeled with radioactive cholesteryl ester (CE) and triglycerides (TG) mimicking chylomicrons was intravenously injected into individuals who regularly weight trained and made regular use of AAS (WT+AAS group), normolipidemic sedentary individuals (SDT group) and individuals who also regularly weight trained but did not use AAS (WT group). Fractional clearance rates (FCR) were determined by compartmental analysis for emulsion plasma decay curves. ResultsFCR-CE for the WT+AAS group was reduced (0.0073+-0.0079min-1, 0.0155+-0.0100min-1, 0.0149+-0.0160min-1, respectively; p<0.05), FCR-TG was similar for both the WT and SDT groups. HDL-C plasma concentrations we...

245

Very low background gamma spectrometer mounted in anti-Compton with NaI(Tl) for the study of glaciers and sediment samples; Spectrometrie gamma a tres bas niveau avec anti-Compton NaI(Tl), pour l`etude des glaciers et des sediments  

The determination of natural and artificial radioactivities of snow (glaciers, polar ice-caps) or sediment samples (lakes, oceans), takes great benefit with the use of the superior resolution of high purity germanium detector, N type, in a broad energy range( 10 keV up to 1.6 MeV). This detector (relative efficiency: 20%), very low background specified, is mounted in anti-Compton with a 9`x 8` NaI(Tl) scintillator, also with low background. International standards, used with a quantitative software allows the determination of the efficiency curve and the isotopes identification and specific activity. The anti-Compton suppressed spectrometer exhibits a decrease of the background by a factor of ten, without any change in efficiencies. Applications of this spectrometer deal with samples from lake Titicaca and a glacier from Spitsbergen. (authors). 6 figs., 7 refs.

246

ADVANCED DIAGNOSTIC TECHNIQUES FOR THREE-PHASE SLURRY BUBBLE COLUMN REACTORS(SBCR)  

This report summarizes the accomplishment made during the third year of this cooperative research effort between Washington University, Ohio State University and Air Products and Chemicals. Data processing of the performed Computer Automated Radioactive Particle Tracking (CARPT) experiments in 6 inch column using air-water-glass beads (150 {micro}m) system has been completed. Experimental investigation of time averaged three phases distribution in air-Therminol LT-glass beads (150 {micro}m) system in 6 inch column has been executed. Data processing and analysis of all the performed Computed Tomography (CT) experiments have been completed, using the newly proposed CT/Overall gas holdup methodology. The hydrodynamics of air-Norpar 15-glass beads (150 {micro}m) have been investigated in 2 inch slurry bubble column using Dynamic Gas Disengagement (DGD), Pressure Drop fluctuations, and Fiber Optic Probe. To improve the design and scale-up of bubble column reactors, a correlation for overall gas holdup has been proposed based on Artificial Neural Network and Dimensional Analysis.

247

French speaking meeting on fuzzy logics and its applications; Rencontres francophones sur la logique floue et ses applications  

The LFA meeting is a opportunity for university searchers and industrialists to meet each others and to present their most recent results on the theory of fuzzy sets and/or on its applications. The domain of applications ranges from the fuzzy control of processes to classifying, pattern recognition, data analysis, decision making, reasoning, image processing and interpretation, data fusion, artificial intelligence or data management systems. This issue of the LFA meeting inaugurates some new theories of uncertainty such as the Dempster-Shafer theory of belief functions or the qualitative approaches. From the 40 communications published in this book, two fall into the Inis scope (radioactive waste management and 3-D NMR imaging of brain tissues) and one into the Etde scope (fuzzy control of an electric-powered vehicle). (J.S.)

248

In situ and laboratory investigation of the alteration of Boom Clay (Oligocene) at the air-geological barrier interface within the Mol underground facility (Belgium): Consequences on kerogen and bitumen compositions  

The Boom Clay formation (Oligocene) is studied as a reference host rock for methodological studies on deep geological disposal of radioactive waste. During excavation of galleries within the Clay formation (HADES underground research facility, Mol, Belgium), the physico-chemical conditions are significantly modified as an air-clay interface is created. In order to study the long-term impact of the air-clay contact on the organic matter contained in the Boom Clay, two types of samples were studied: (1) a reference series of clay samples having been in contact with the atmosphere of the HADES gallery for increasing times up to several years and (2) unaltered clay samples submitted to artificial oxidation in a ventilated oven at 80^oC. The evolution of geochemical data of the two series was c...

249

Illustration of constrained composition statistical methods in the interpretation of radionuclide concentrations in the moss Pleurozium schreberi.  

In this work we have used moss Pleurozium schreberi as a bioindicator of radioactive materials in environment. The following radionuclides were determined in moss samples: (137)Cs, (40)K, (210)Pb, (212)Pb, (214)Pb, (214)Bi, (231)Th, (235)U and (228)Ac, but not all of them in each sample. The highest activity concentrations were found for naturally occurring (210)Pb, (40)K and the artificial isotope (137)Cs. Activities of radioisotopes were recalculated into mass concentrations and the statistical methods intended for constrained data processing were used. Analysis of our results showed at most a weak relationship between radioisotope mass concentrations in moss. It was supposed that concentrations of some elements depended on the same, currently unknown, factors. PMID:22673224

250

The history of the discovery of nuclear fission  

Following with the discovery of the electron by J. J. Thomson at the end of the nineteenth century a steady elucidation of the structure of the atom occurred over the next 40?years culminating in the discovery of nuclear fission in 1938?1939. The significant steps after the electron discovery were: discovery of the nuclear atom by Rutherford (Philos Mag 6th Ser 21:669?688, 1911), the transformation of elements by Rutherford (Philos Mag 37:578?587, 1919), discovery of artificial radioactivity by Joliot-Curie and Joliot-Curie (Comptes Rendus Acad Sci Paris 198:254?256, 1934), and the discovery of the neutron by Chadwick (Nature 129:312, 1932a, Proc R Soc Ser A 136:692?708, 1932b; Proc R Soc Lond Ser A 136:744?748, 1932c). The neutron furnished scientists with a particle able to penetrate ato...

251

On variations of volumetric activity of 90Sr and 137Cs in the Baltic Sea coastal waters near the shore of Lithuania in 2005?2009  

The article presents the measurement results of the volumetric activity (VA) of artificial radionuclides 90Sr and 137Cs in the coastal waters of the Baltic Sea near the Curonian Peninsula in 2005?2009. The annual average values for this period of time were 12?Bq/m3 (90Sr) and 40?Bq/m3 (137Cs). Considerable variations in the VA of the radionuclide in individual measurements compared to the average results were observed. The extreme values were 6 and 16?Bq/m3 for 90Sr and for 137Cs?27 and 75?Bq/m3. It is proposed to allow such variations under the influence of a variety of external factors such as hydro meteorological situations, inflowing rivers and bays, storm activity and etc. Besides, a possibility of penetration of radionuclides into the sea waters from the additional radioactive source...

252

Forest vegetation as a sink for atmospheric particulates: Quantitative studies in rain and dry deposition  

Radionuclides in the atmosphere are associated with nonradioactive air particulates and hence serve to trace the fluxes of air particulates to various surfaces. Natural and artificial radioactivities found in the atmosphere have been measured in vegetation for 10 years to elucidate some of the mechanisms of acquirement by forest trees of atmospheric particulates. Whole tree analysis, in conjunction with soil assay, have served to establish the fraction of the flux of radionuclides retained by above-ground tissues of a forest stand. Interpretation is facilitated because most radionuclides in the atmosphere are superficially acquired. Typically 5--20% of the total open field flux is retained by the forest canopy in a moderately rainy climate (120 cm/year). Short-lived daughters of radon give a dry deposition velocity of particulates in the Aitken size range of 0.03--0.05 cm/s, thus permitting an estimate of transient removal by forest canopies by dry deposition of this size fraction.

253

In situ hybridization assays for localization of the chronic bee paralysis virus in the honey bee (Apis mellifera) brain  

Chronic bee paralysis virus (CBPV) is a common single-stranded RNA virus which may cause significant losses in honey bee colonies. As this virus seems to exhibit neurotropism, an in situ hybridization based method was developed to localize the genomic and antigenomic CBPV RNAs in infected honey bee brains. Double-stranded cDNA probes as well as genomic and antigenomic-specific single-stranded cDNA probes were prepared, using the polymerase chain reaction in presence of labelled d-UTP with non-radioactive digoxigenin. Both genomic and antigenomic RNAs were detected the brain of honey bee infected naturally or artificially. Hybridization signals were obtained in some somata and neuropile regions of the brain. In particular, high signals were observed at the level of the mushroom bodies and c...

254

On variations of volumetric activity of 90Sr and 137Cs in the Baltic Sea coastal waters near the shore of Lithuania in 2005?2009  

The article presents the measurement results of the volumetric activity (VA) of artificial radionuclides 90Sr and 137Cs in the coastal waters of the Baltic Sea near the Curonian Peninsula in 2005?2009. The annual average values for this period of time were 12 Bq/m3 (90Sr) and 40 Bq/m3 (137Cs). Considerable variations in the VA of the radionuclide in individual measurements compared to the average results were observed. The extreme values were 6 and 16 Bq/m3 for 90Sr and for 137Cs?27 and 75 Bq/m3. It is proposed to allow such variations under the influence of a variety of external factors such as hydro meteorological situations, inflowing rivers and bays, storm activity and etc. Besides, a possibility of penetration of radionuclides into the sea waters from the additional radioactive source...

255

Chemosensory basis of behavioural plasticity in response to deterrent plant chemicals in the larva of the Small Cabbage White butterfly Pieris rapae.  

Behavioural and electrophysiological responsiveness to three chemically different secondary plant substances was studied in larvae of Pieris rapae L. (Lepidoptera: Pieridae). Three groups of caterpillars were studied that during their larval development were exposed to different rearing diets: an artificial diet or one of two host-plants, cabbage, Brassica oleracea, or nasturtium, Tropaeolum majus. In dual-choice leaf disc assays, caterpillars reared on cabbage were strongly deterred by the phenolic chlorogenic acid, the flavonol glycoside naringin and the alkaloid strychnine. However, behavioural plasticity was found in caterpillars reared on nasturtium or artificial diet in that these did not discriminate against chlorogenic acid. Caterpillars reared on the artificial diet were also significantly less sensitive to naringin and strychnine in the behavioural assay. Electrophysiological studies of the maxillary sensilla styloconica revealed that the deterrent neuron in the medial sensillum, but not in the lateral sensillum, of cabbage-reared caterpillars was more sensitive than the same neuron type of caterpillars reared on nasturtium or artificial diet. We conclude that (1) the diet-induced behavioural habituation to deterrents can at least partly be explained by chemosensory desensitisation of a generalist type of maxillary deterrent neuron; (2) behavioural cross-habituation to the three structurally diverse deterrent compounds can be traced back to cross-sensitivity for these compounds in the same gustatory neuron. PMID:19414011

256

Neural Mechanisms of Short-term Plasticity in the Human Visual System.  

Following circumscribed retinal damage, extensive reorganization of topographically organized visual cortical areas has been demonstrated in several species of mammals (including humans). Although reorganization is often studied over extended time scales, neural response properties change within seconds of retinal deafferentation. Understanding the mechanisms underlying these short-term effects is essential for developing a complete picture of representational plasticity. One approach to the study of short-term plasticity has been to use an artificial scotoma, a stimulus-induced analog of a retinal scotoma, as a model. Here, we use event-related potentials in an artificial scotoma paradigm to examine 2 aspects of short-term plasticity in the human visual system. First, we investigated the changes within visual representations temporarily deprived of patterned visual input by probing the inner boundaries of an artificial scotoma. We found an enhanced early sensory P1, consistent with a reduction in inhibition (disinhibition), a proposed mechanism of short-term visual plasticity. Second, we investigated mechanisms through which representations of surrounding space invade a visually deprived area by probing the outer boundaries of an artificial scotoma. In this case, a later visual component, the N1, was enhanced, suggesting that feedback may provide a source of unmasked, or invading, activity to visually deprived representations. PMID:22235030

257

Biologically inert synthetic dural substitutes. Appraisal of a medical-grade aliphatic polyurethane and a polysiloxane-carbonate block copolymer.  

Two types of artificial membranes, a medical-grade aliphatic polyurethane and a polysiloxane-carbonate block copolymer, were tested as substitutes for dura in 24 and 12 rabbits, respectively. The films were placed either epidurally, subdurally, or as dural grafts in equal subgroups of animals. The postoperative course was uneventful with no manifestations of convulsive disorder or cerebrospinal fluid leak. The animals were sacrificed 3, 6, or 9 months after implantation of the artificial membranes. Both types of artificial membranes were easily removed from the underlying nervous and the other surrounding tissues. The histological examination failed to reveal adhesions, neomembrane formations, or any type of foreign body reactions to the polyurethane film. The implantation of the polysiloxane-carbonate film caused no reaction when it was applied epidurally. As a dural graft, the polysiloxane-carbonate copolymer induced the formation of a thin neomembrane of one to two layers of fibroblasts which formed a watertight seal of the dural defect. A similar thin neomembrane was found to encase this artificial membrane in the group of animals in which it was implanted subdurally. There was no foreign body reaction to the polysiloxane-carbonate film. The authors conclude that these materials hold promise as dural substitutes or in the prevention of spinal dural scarring, and should be evaluated clinically. PMID:2230977

258

Boundary treatment effects on molecular dynamics simulations of interface thermal resistance  

Molecular Dynamics simulations of heat conduction in liquid Argon confined in Silver nano-channels are performed subject to three different thermal conditions. Particularly, different surface temperatures are imposed on Silver domains using a thermostat in all and limited number of solid layers, resulting in heat flux in the liquid domain. Alternatively, energy is injected and extracted from solid layers to create a NVE liquid Argon system, which corresponds to heat flux specification. Imposition of a constant temperature region in the solid domain results in an unphysical temperature jump, indicating the presence of an artificial thermal resistance induced by the thermostat. Thermal resistance analyses for the components of each case are performed to distinguish the artificial and interface thermal resistance effects. Constant wall temperature simulations are shown to exhibit superposition of the artificial and interface thermal resistance values at the liquid/solid interface, while applying thermostat on wall layers sufficiently away from the liquid/solid interface results in consistent predictions of the interface thermal resistance. Injecting and extracting energy from each solid layer eliminates the artificial resistance. However, the method cannot directly specify a desired temperature difference between the two solid domains.

259

Application of {sup 137}Cs and {sup 210}Pb radionuclides to determine sedimentation rates of recent sediments from Admiralty Bay, Antarctica Peninsula  

Studies about natural and artificial radionuclides in areas such as the Antarctic are key to understand natural and dynamic processes in marine environments. These studies are important to determine levels of radioactive elements and local sedimentation rates. Five marine sediment cores were collected in different points of Admiralty Bay, in the Antarctic Peninsula. The purpose of this study was to determine {sup 137}Cs, {sup 226}Ra and {sup 210}Pb and sedimentation rates at each site. {sup 137}Cs, {sup 210}Pb and {sup 226}Ra were assayed by gamma-counting through direct measurement of the peak at 661 keV, 47 keV and 609 keV, respectively. Sedimentation rates were obtained by {sup 137}Cs and {sup 210}Pb (CIC and CRS). The activities for {sup 137}Cs ranged from 0.84 to 7.09 Bq kg{sup -1}; to {sup 226}Ra from 6.77 to 31.07 Bq kg{sup -1} for {sup 210}Pb ranged from 1.10 to 36.90 Bq kg{sup -1}. The sedimentation rates obtained by the three models ranged from 0.11+-0.01 cm y{sup -1} to 0.46+-0.05 cm y{sup -1}. The levels of {sup 137}Cs registered in this study, as well as in other studies in the Antarctic region indicate that global fallout is the main cause of artificial radionuclides present in this environment, since the Antarctic has not suffered a direct action of human activities that released radioactive elements. The possible grain size variations that occur in the studied points of Admiralty Bay may explain the differences found in the vertical distribution of radionuclides, because of the different values of sedimentation rates and respective dating determined in their profiles. (author)

260

Microbe-mineral interactions in naturally radioactive beach sands from Espirito Santo, Brazil: experiments on mutagenicity.  

Previous studies on naturally radioactive materials suggested that they can have a mutagenic effect on plants (growing in sands in Kerala, South West India), and on bats (dwelling in an abandoned underground mine of primary monazite ore in Namaqualand, Western Cape, South Africa). We hypothesised, based on previous theoretical work, that radioactive sands would not induce mutants in microorganisms over time scales typical of doubling times in the natural environment. The potential of exceptionally monazite (Th)-rich mineral sands collected from the coast of Espirito Santo, Brazil to induce single-point reversion in Escherichia coli cultures (both repair-competent and repair-deficient strains) was tested using the tryptophan reverse mutation assay. The results show that at least on a short-term scale (1-7 days), the monazite-rich sands did not cause an increase in reversion above background. PMID:17361436

 
 
 
 
261

Ion source development for the on-line isotope separator at JAEA  

A forced electron beam induced arc discharge (FEBIAD-B2) type ion source and a surface ionization type one with a uranium target have been developed for the JAEA-ISOL. The ion sources were utilized to produce medium-heavy neutron-rich radioactive ion beams for acceleration with Tokai radioactive ion accelerator complex (TRIAC). In the FEBIAD-B2 type ion source, a target container containing about 1 g/cm2 of 238UCx target is directly attached to a plasma chamber. While the surface ionization type one, 238UCx target is located inside the ion source as an internal target. With both ion sources, about 100 isotopes produced in the proton-induced fission of uranium with separation efficiencies of 0.1 30% have been mass-separated.

262

EURISOL Multi-MW Target Station - MAFF Configuration - Neutron Fluxes, Fission Rates, Dose Rates and Activation  

The EURISOL (The EURopean Isotope Separation On-Line Radioactive Ion Beam) project aims atproducing high intensity radioactive ion beams produced by neutron-induced fission on fissile targets(235U) surrounding a liquid mercury converter. A proton beam of 1GeV and 4MW impinges on theconverter, generating, by spallation reactions, high neutron fluxes that induce fission in thesurrounding fissile targets.In this work the state-of-the-art Monte Carlo codes MCNPX and FLUKA were used to assess theneutronics performance of the system, which geometry, inspired in the MAFF concept, allows aversatile manipulation of the fission targets. The first objective of the study was to optimize thegeometry and the materials used in the fuel and reflector elements of the system, in order to achievethe highest possible fission rates. Indeed, it is shown that the appropriate combination of fission targetmaterial and surrounding reflector material leads to the aimed value of 1015 fissions/s per fissiontarget. The second part of this...

263

Fast Neutron Dosimetry and Spectrometry Using Radioactivation; DOSIMETRIE ET SPECTROMETRIE DES NEUTRONS RAPIDES PAR RADIOACTIVATION  

A review of general information concerning induced radioactivity detectors is presented along with tables summarizing the properties of detector elements which may be used in radioprotection. The excitation functions found in the literature are also given. The technological characteristics of the detectors used are given, together with the counting methods. The many advantages of activation dosimetry for strong or periodic neutron fluxes and for those in the presence of gamma -radiation are stressed. The main problem in activation dosimetry is, however, the calculation of the dose absorbed from the results of the measurements. It is shown how the dose is expressed, fairly accurately, as a function of the radioactivities induced in a series of detectors. As an example, the spectrometry and the dosimetry of the neutron flux emitted by a Po -Be source are presented. (auth)

264

Rapid blood clearance of biotinylated IgG after infusion of avidin  

The techniques of immunotherapy and radioimmunoimaging suffer from the problem of background: intravenously injected antibodies remain in the circulation much longer than it is necessary for effective binding to the target. Various approaches, including the postinjection of second antibodies, were explored to overcome the problem with some success. The phenomenon of a 100-fold more rapid blood clearance of biotinylated immunoglobulins after postinjection of an equivalent dose of avidin is described. The concentration of /sup 125/I-labeled biotinylated IgG in the circulation of rats slowly decreased to 20% of initial in 24 hr. Avidin injection at any interval during this period induced 90-95% reduction of radioactivity in blood in 15 min. Up to 70% of the radioactivity was recovered in the liver. Avidin-induced blood clearance of biotinylated immunoglobulins may find applications in immunotherapy and radio- or nuclear magnetic resonance immunoimaging.

265

Toward Application of a Thick Gas Electron Multiplier (THGEM) Readout for a Dark Matter Detector  

The Yale-Weizmann collaboration aims to develop a low-radioactivity (low-background) cryogenic noble liquid detector for Dark-Matter (DM) search in measurements to be performed deep underground as for example carried out by the XENON collaboration. A major issue is the background induced by natural radioactivity of present-detector components including the Photo Multiplier Tubes (PMT) made from glass with large U-Th content. We propose to use advanced Thick Gaseous Electron Multipliers (THGEM) recently developed at the Weizmann Institute of Science (WIS). These "hole-multipliers" will measure in a two-phase (liquid/gas) Xe detector electrons extracted into the gas phase from both ionization in the liquid as well as scintillation-induced photoelectrons from a CsI photocathode immersed in LXe. We report on initial tests (in gas) of THGEM made out of Cirlex (Kapton) which is well known to have low Ra-Th content instead of the usual G10 material with high Ra-Th content.

266

Radiologic assessment of a self-shield with boron-containing water for a compact medical cyclotron  

The cyclotron at our hospital has a self-shield of boron-containing water. The amount of induced radioactivity in the boron-containing water shield of a compact medical cyclotron has not yet been reported. In this study, we measured the photon and neutron dose rates outside the self-shield during cyclotron operation. We estimated the induced radioactivities of the boron-containing water used for the self-shield and then measured them. We estimated the activation of concrete outside the self-shield in the cyclotron laboratory. The thermal neutron flux during cyclotron operation was estimated to be 4.72 ?? 102 cm???2 s???1, and the activation of concrete in a cyclotron laboratory was about three orders of magnitude lower than the clearance level of RS-G-1.7 (IAEA). The activity concentra...

267

Ploidy distribution of tumour cells derived from induced and spontaneously arising metastases of a murine radiation-induced sarcoma, RIF-1  

Flow cytometric analysis of the X-radiation-induced sarcoma RIF-1 has shown that the parent tumour is composed of diploid and tetraploid subpopulations of cells, each capable of independent proliferation. We have now examined artificially induced and spontaneously arising metastases of the RIF-1 tumour and have found in both cases that, unlike the parent tumour from which they are derived, they exhibit a single level of ploidy which is stable throughout successive in vivo and in vitro passaging. This finding suggests that at least in this tumour system metastasis is a clonal event.

268

Construction of Stress Responsive Synthetic Promoters and Analysis of Their Activity in Transgenic Arabidopsis thaliana  

To obtain strong inducible promoters to drive abiotic stress-inducible transgene expression with minimal negative effects, we constructed three artificial synthetic promoters (EKCM, EKCRM, and ECCRM) comprising multiple cis-acting stress-response elements. Each promoter was fused independently to the ?-glucuronidase (GUS) reporter gene, and GUS expression was analyzed in stable expression systems in Arabidopsis thaliana. T2 transgenic progenies showed integration of the promoter-GUS construct in their genome. RT-PCR assays and histochemical staining analysis showed that GUS expression driven by each promoter increased under desiccation, cold, and high salt conditions. The activity of synthetic promoters, assessed by fluorometric quantitative analysis of GUS enzyme activity, was significant...

269

Fibrinogen substitution improves whole blood clot firmness after dilution with hydroxyethyl starch in bleeding patients undergoing radical cystectomy: a randomized, placebo-controlled clinical trial  

Summary. Background: Infusion of artificial colloids such as hydroxyethyl starch (HES) induces coagulopathy to a greater extent than simple dilution. Several studies have suggested that the coagulopathy could be corrected by substitution with a fibrinogen concentrate. Objectives: The aims of the present prospective, randomized, placebo-controlled trial were to investigate the hemostatic effect of a fibrinogen concentrate after coagulopathy induced by hydroxyethyl starch in patients experiencing sudden excessive bleeding during elective cystectomy. Methods: Twenty patients were included. Blood loss was substituted 1:1 with HES 130/0.4. At a dilution level of 30%, patients were randomly selected for intra-operative administration of a fibrinogen concentrate or placebo. The primary endpoint w...

270

Muscle-powered Cantilever for Microtweezers with an Artificial Micro Skeleton and Rat Primary Myotubes  

A technique to attach muscle cells to artificial micro mechanical systems was studied using dog body hair and rat primary skeletal muscle. Muscle-powered cantilever for microtweezers were fabricated which consisted of a single strand of hair for the skeleton and differentiated myotubes for the actuator. The three-dimensional mechanical part of the microtweezers was fabricated using a focused ion beam-induced ion milling technique. The micro hair skeleton was used as a scaffold for the muscular cells and the mechanical structure. Electrical stimulation induced related contraction of the myotubes and displacement of the muscle-powered cantilever of the microtweezers, although the displacement was not yet enough for useful microtools.   

271

An impairment of cortical GABAergic neurons is involved in alkalosis-induced brain dysfunctions  

Acid-base imbalance leads to pathological cognition and behaviors in the clinical practices. In the comparison with acidosis, the cellular mechanisms underlying alkalosis-induced brain dysfunction remain unclear. By using electrophysiological approach, we investigated the influences of high extracellular pH environment on cortical GABAergic neurons in terms of their responsiveness to synaptic inputs and their ability to produce action potentials. Artificial cerebral spinal fluid in high pH impairs excitatory synaptic transmission and spike initiation in cortical GABAergic neurons. The alkalosis-induced dysfunction of GABAergic neurons is associated with the decrease of receptor responsiveness and the increases of spike refractory periods and threshold potentials. Our studies reveal that al...

272

PC12 polarity on biopolymer nanogratings  

Cell differentiation properties are strongly entangled with the morphology and physical properties of the extracellular environment. A complete understanding of this interaction needs artificial scaffolds with controlled nano-/micro-topography. We induced specific topographies by nanoimprint lithography (NIL) on tissue culture polystyrene (TCPS) dishes substrates and, using light microscopy and high-magnification scanning-electron-microscopy, quantitatively compared the changes in PC12 differentiation phenotype induced by the periodicity of the nanopatterns. This analysis revealed that nanogratings reduce the number of neurites produced by PC12 cells upon treatment with NGF and that neuronal bipolarity correlated with an increased stretching of the cell body and a reduced length of the cell neuronal protrusions.

273

PC12 polarity on biopolymer nanogratings  

Cell differentiation properties are strongly entangled with the morphology and physical properties of the extracellular environment. A complete understanding of this interaction needs artificial scaffolds with controlled nano-/micro-topography. We induced specific topographies by nanoimprint lithography (NIL) on tissue culture polystyrene (TCPS) dishes substrates and, using light microscopy and high-magnification scanning-electron-microscopy, quantitatively compared the changes in PC12 differentiation phenotype induced by the periodicity of the nanopatterns. This analysis revealed that nanogratings reduce the number of neurites produced by PC12 cells upon treatment with NGF and that neuronal bipolarity correlated with an increased stretching of the cell body and a reduced length of the cell neuronal protrusions.

274

Antiferromagnetism of hybrid metamaterials  

We analyze a metal-dielectric structure composed of a silicon nanoparticle coupled to a stack of split-ring resonators, and reveal the possibility of optically-induced antiferromagnetic response of such a hybrid meta-molecule with a staggered pattern of the induced magnetization. We show that a hybrid metamaterial created by a periodic lattice of the meta-molecules supports antiferromagnetic modes with a checker-board pattern and the propagation of spin waves, opening new ways for manipulating artificial antiferromagnetism at high frequencies with low-loss materials.

275

20. ATSR congress - Book of abstracts; 20eme congres ATSR - Recueil des resumes  

This document brings together the abstracts of all presentations given at the 20. congress of the French association for radiation protection techniques and sciences (ATSR). Content: - Use of radioactive sources: 1 - Role of the inter-ministry Commission of artificial radioelements (CIREA) in the medical, research and industry domains (Denis-Philippe Fages, CIREA Fontenay-aux-Roses); 2 - Radiation protection and ionic smoke detectors (Catherine Bougie, labour inspection DDTE, Montigny-Le-Bretonneux); 3 - radioactive wastes and effluents management in hospitals (Vincent Carlier, ANDRA Chatenay-Malabry); - Nuclear law and its applications: 4 - environmental effects on public health and why the environment health safety system needs to be reformed (Andre Aschieri, House of Commons); 5 - Radiation sources safety and radioactive materials security: IAEA's action plan (Robert Ouvrard, IAEA, Austria); - Radon risk: 6 - Radon risk epidemiology in France (Margot Tirmarche, Helene Baysson, Dominique Laurier, IPSN - Fontenay-aux-Roses); 7 - Radon risk: polonium effects (Jacques Pradel, Gr.COM/AEPN, Paris); 8 Training of civil engineering and public work professionals with regards to radon and its decay products (Marc Ammerich, CEA Saclay, F. Gauffre, Montpellier 2 Univ., M-C. Robe, IPSN); - Radioactive wastes: 9 - Radio-elements transmutation, status and perspectives (Thomas Kirchner - Ecole des Mines Nantes); 10 - Management of low-level radioactive wastes generated by accelerators (Manfred Hoefert, Doris Forkel-Wirth, Claude Lamberet, CERN Switzerland); 11 - Summary of the French legislation about wastes (Christian Bataille, House of Commons); - Impact on the public: 12 - Use of radionuclides in environmental studies (Xavier Vitart - CEA/DAMRI/SAR); 13 - Energy and environment (Jacques Frot - GR.COM/AEPN); - Impacts on public and on the environment: 14 - Low dose effects (Roland Masse, Academy of Sciences); 15 - The stakes of radioactivity measurements (Jean Charles Abbe, CNRS, Nantes Univ.); - Conference: 16 - Works of art expertise using X-ray spectroscopy (Albert Adam, CEA-Saclay); - Effects on the organism: 17 - health issues with high level wastes (Jacques Lafuma, Academy of Sciences, Academy of Medicine); 18 - Summary of epidemiological studies of the leukemia risk near nuclear sites (Dominique Laurier, IPSN Fontenay-aux-Roses); 19 - Quantification of leukemia risk in relation with a chronic exposure to ionising radiations: lessons learnt by the Nord-Cotentin radioecological group (Catherine Rommens, Dominique Laurier, IPSN Fontenay-aux-Roses); - Radioecology: 20 - From radiation to risk: the Nord-Cotentin radioecological group model (Aurelie Merle-Szeremeta, Catherine Rommens, Caroline Drombry, IPSN Fontenay-aux-Roses); 21 - Interpretation of calculation code results about the radiological impacts of radioactive releases (Henri Maubert, SPR/CEA Cadarache); - Use of radiations at hospitals: 22 - Improvement of the radioactive waste management of a regional cancer centre (Sandrine Laugle, Jean-Claude Houy, Eugene Marquis Centre Rennes); 23 - Detection of a radioactive source in an incineration plant dumpster: decision-making study according to the activity calculation (Jean-Claude Houy, Sandrine Laugle, Eugene Marquis Centre Rennes); - Environment: 24 - Model or measurements: what strategy for an environmental contamination estimation? (Caroline Drombry-Ringeard, Hemispheres Egly, Catherine Rommens, IPSN Fontenay-aux-Roses); 25 - Radiological risks magnitude (Jean Charles ABBe, CNRS, Nantes Univ.); 26 - Radiological monitoring of La Hague site environment (Philipp Blaise, H. Truffert, Cogema La Hague); - Posters: Po 01 - Inter-laboratory comparison of French low-energy anthropo-diametric measurements (D. Franck, Ph. Berard, C. Dubiau, R. Soulie, IPSN Fontenay-aux-Roses); Po 02 - Modification principles of the CEA Cadarache radiological monitoring plan (Elodie Panaiva-Pouzol, Serge Escallon, Henri Maubert, SPR/CEA Cadarache)

276

Enhanced excitation of Giant Pairing Vibrations in heavy-ion reactions induced by weakly-bound projectiles  

The use of radioactive ion beams is shown to offer the possibility to study collective pairing states at high excitation energy, which are not usually accessible with stable projectiles because of large energy mismatch. In the case of two-neutron stripping reactions induced by 6He, we predict a population of the Giant Pairing Vibration in 208Pb or 116Sn with cross sections of the order of a millibarn, dominating over the mismatched transition to the ground state.

277

Introduction to EFNUDAT  

Efforts are directed towards the minimization, management and disposal of highly radioactive nuclear waste. Partitioning of nuclear waste and transmutation of long-lived isotopes are subject of investigations. These studies imply the needs for the underlying nuclear databases. In this respect, accurate knowledge of neutron and proton induced nuclear reactions in the intermediate- and high-energy domains is important and EFNUDAT aims at networking European facilities for such nuclear data measurements.

278

Investigation into the safety of the nuclear power plants in the Hamburg area, sited at Brokdorf, Brunsbuettel, Kruemmel, and Stade. Pt. 2. Analysis of the consequences of selected core meltdown accidents. Expert opinion made on behalf of the Free and Hanseatic Town of Hamburg. Untersuchung ueber die Sicherheit der im Hamburger Umland gelegenen Kernkraftwerke Brokdorf, Brunsbuettel, Kruemmel und Stade. T. 2. Untersuchung der Auswirkungen ausgewaehlter Kernschmelzunfaelle. Gutachten erstellt im Auftrag der Freien und Hansestadt Hamburg  

Induced by serious doubts about the safety of the four nuclear power stations KBR, KKB, KKK, and KKS, this second part of te expert opinion examines and discusses core meltdown accidents in a BWR-type and a PWR-type reactor. The study takes into account radioactivity release and retention potentials of the reactor pressure vessel and containment building, the source terms, the radiological dose calculation models, and the resulting radiation exposure. (DG).

279

New Nuclear And Subnuclear Exotic Decays  

In this paper new nuclear and subnuclear exotic decays are investigated. Some theoretical problems of the pionic radioactivity, such as fission-like models, applicable to all kind of exotic nuclear and subnuclear decays are presented. The induced nuclear and subnuclear decays are discussed. Moreover, using the recent results on the spontaneous fission half lives T of the heavy nuclei with Z new predictions on the pionic yields in the region of superheavy elements are presented.

280

Calculation of the energy deposition in a water beam dump  

The energy deposition per interacting proton in GeV/cm/sup 3/ and the star density in star/cm/sup 3/ have been calculated in a water cylinder with a Monte Carlo computer program. These calculations permit the estimation of the temperature rise, induced radioactivity, etc., in beam dumps of high energy accelerator and storage rings. The calculation assumed a cylinder of different diameters and lengths and an incident proton beam energy of 20, 200, 300 and 400 GeV. (5 refs).

 
 
 
 
281

Radiation Shielding at High-Energy Electron and Proton Accelerators  

The goal of accelerator shielding design is to protect the workers, general public, and the environment against unnecessary prompt radiation from accelerator operations. Additionally, shielding at accelerators may also be used to reduce the unwanted background in experimental detectors, to protect equipment against radiation damage, and to protect workers from potential exposure to the induced radioactivity in the machine components. The shielding design for prompt radiation hazards is the main subject of this chapter.

282

Development of a method for analyzing traces of ruthenium in plant materials and determination of the transfer factors soil/plant for ruthenium compounds from reprocessing plants  

In an artificial humous and sandy soil spiked with /sup 106/Ru as RuO/sub 2/ and RuCl/sub 3/, pasture grass was grown under artificial illumination in our laboratory. The amounts of ruthenium taken up by the plants were determined by ..gamma..-spectrometry. For open-air investigations with pasture grass, wheat and potatoes inactive ruthenium(III) chloride and ruthenium nitrosylchloride were used. Ruthenium was determined by electrothermal atomic absorption spectrometry (ETAAS) after destroying the organic material and concentrating the solution. The concentration and chemical form of the ruthenium exert an unimportant influence on the transfer factor. For the pasture-grass, the stems of wheat and the weed of potatoes it amounts to 0.00005 to 0.0015, for the ear of wheat to about 0.00005. In peeled potatoes there was no ruthenium detectable, therefore the limit of detection leads to a transfer factor less than or equal to 0.00001. So it is evident that ruthenium is little available for the roots of the plants. In the event of an accident in a nuclear plant the uptake of radioactive ruthenium by roots has only negligible radioecological consequences. This applies even if 50 years of ruthenium enrichment in the soil are assumed.

283

LANDSAT data as a basis for regional environmental assessment within the Columbia Plateau  

LANDSAT data are being used to assist in classifying land cover for the purpose of providing regional environmental assessments of a 105,000 km/sup 2/ area within the Columbia Plateau region of the northwestern United States. The environmental assessment is being performed in conjunction with siting a radioactive waste terminal-storage facility within the federally operated Hanford Site in south-central Washington. Initial assessments involved classification of four contiguous LANDSAT scenes recorded over the region during the summer of 1975 and about 300 1978 high-altitude (U-2) photographs. The resulting mosaic was segregated into ten land-cover classes. The classified land-cover data were then machine-integrated with digital irrigation well-location data taken from the US Geological Survey's Ground-Water Site Inventory. The resulting groundwater multi-source data product was required by hydrologists to segregate potential artificial recharge areas from artificial groundwater discharge areas. Related studies have employed LANDSAT data and aerial imagery to identify linear structures and other geologic features which may have a significant bearing on the tectonic and/or hydrologic setting of the Columbia Plateau. Future plans call for attempts to correlate land-cover patterns with other physical and environmental parameters such as digital terrain and hydrometeorological data.

284

[sup 81m]Kr scintigraphic evaluation of hemodynamics in gynecologic malignancies under condition of Angiotensin II-induced hypertension  

Transcatheter arterial infusion chemotherapy is one of the most useful therapeutic procedures for gynecologic malignancies. Although reports have been published about Angiotensin II-induced hypertension chemotherapy and its efficacy, there have been no reports to evaluate an application for gynecologic malignancies. We evaluated the usefulness of the method for gynecologic malignancies demonstrating the changes of hemodynamics of the tumor using [sup 81m]Kr scintigraphy. 13 patients with pathologically confirmed gynecologic malignancies were evaluated by angiography and continuous infusion of [sup 81m]Kr via catheter with and without Angiotensin II. At first, continuous infusion of [sup 81m]Kr was performed under superselective catheterization of the uterine artery. Radioactivities in the ROI were counted. Then, withdrew the catheter from the uterine artery to the internal iliac artery, and again continuously infused [sup 81m]Kr and counted radioactivities in the same ROI. Finally, keeping the catheter in internal iliac artery, Angiotensin II and [sup 81m]Kr were infused simultaneously. And counted the radioactivities. The radioactivities were highest when the catheter tip was placed in uterine arteries and lowest when the catheter tip was placed in internal iliac arteries. But radioactivities in the ROIs were definitely increased when Angiotensin II was used, even if the catheter tip was keeping in the internal iliac arteries. The optimal catheter position of transcatheter arterial chemotherapy for gynecologic malignancies is at proximal uterine artery. Since Angiotensin II-induced hypertension may increase blood flow of tumors, it seems to have indication for postoperative cases, highly advanced cases and cases with difficulties to perform superselective catheterization. From our experience, we believe chemotherapeutic agents must be administrated via catheter within 3 minutes after infusion of Angiotensin II. (author).

285

Excretion of (3H)prednisolone in clinically normal and experimentally infected bovine udders  

The excretion rate of (3H)prednisolone from clinically normal and experimentally infected udders of 10 lactating cows was studied. Each quarter of 6 cows was injected with a single dose of (3H)prednisolone mixed with non-radioactive prednisolone equivalent to 10 mg in 10 ml of peanut oil base. Each of the remaining 4 cows was given 40 mg of nonradioactive prednisolone and (3H)prednisolone in 60% ethanol IV. Control and postadministration samples of blood, milk, and urine were examined for radioactivity. The effects of (3H)prednisolone were evaluated in the same cows, first in clinically normal udders, then 2 weeks later in udders experimentally infected with Streptococcus agalactiae. Absorption and elimination of prednisolone were the same before and after induced infection. Within 3 hours after intramammary injection, 95% of the labeled prednisolone was absorbed systemically, less than 5% of this dose was recovered in milk, and 29% was excreted in urine. After IV injection of (3H)prednisolone, less than 0.2% of the total radioactivity was recovered in milk and less than 46% was excreted in urine. Clinical mastitis induced by S agalactiae was moderate. Circulating blood leukocytes and somatic cells in the milk of normal cows remained essentially unchanged. The leukocyte response to induced infection was rapid in blood and milk. Large numbers of leukocytes were noticed in the milk and a severe leukopenia occurred. Prednisolone treatment did not alter the number of somatic cells in milk or reduce the inflammatory response of experimentally infected cows.

286

Basic Information about Radionuclides Rules  

... types have naturally occurring trace amounts of "mildly radioactive" elements (radioactive elements with very long half-lives) that serve as the "parent" of other radioactive contaminants ("daughter products"). These radioactive contaminants, depending on ...

287

Procedures for radioactive I-131  

Details of the radioactive I-131 administration and radiation safety considerations are presented. Topics covered include patient survey, radioactive labelling, levels in patients containing radioactivity, hospital discharge of radioactive patients, and nursing procedures.

288

Laboratory calibrations of airborne gamma-ray spectrometers. Measurements and discussions of important parameters  

This report is the fourth of reports from The Department of Electrophysics covering measurement and interpretation of airborne gamma-spectrometry measurements. It describes different topics concerning the construction of a suitable calibration setup in the laboratory. The goal is to build a simple and cheap laboratory setup that can produce most of the gamma-ray data needed for an interpretation of spectra measured 50 to 120 m above ground level. A simple calibration setup has been build and tested. It may produce gamma-ray spectra similar to those measured in the air - from surface contamination with artificial nuclides and from `bulk` natural radioactivity. It is possible to investigate the influence of the air above an aircraft carrying the detector (skyshine: scattering of gamma photons in the air above the detector). In order to reduce the influence of non-detected pile-up the count rates are kept low without reaching levels where the background spectra (to be subtracted) would cause unacceptable counting statistical fluctuations. Sources selected for the calibrations are heavy minerals sand (with thorium and uranium), potassium nitrate (with {sup 40}K). These sources are `bulk sources` of natural radioactivity. Cesium-137 has been selected as the basic artifical surface contamination nuclide. The report also discusses methods for comparing two spectra a priori assumed equal. Finally the properties of some materials that could be used as `air-substitutes` in the calibration setup have been tested with respect to stability against moisture sorption. (au).

289

Technical reliability of geological disposal for high-level radioactive wastes in Japan. The second progress report. Part 3. Safety assessment for geological disposal systems  

Based on the Advisory Committee Report on Nuclear Fuel Cycle Backend Policy submitted to the Japanese Government in 1997, JNC documents the progress of research and development program in the form of the second progress report (the first one published in 1992). It summarizes an evaluation of the technical reliability and safety of the geological disposal concept for high-level radioactive wastes (HLW) in Japan. The present document, the part 3 of the progress report, concerns safety assessment for geological disposal systems definitely introduced in part 1 and 2 of this series and consists of 9 chapters. Chapter I concerns the methodology for safety assessment while Chapter II deals with diversity and uncertainty about the scenario, the adequate model and the required data of the systems above. Chapter III summarizes the components of the geological disposal system. Chapter IV refers to the relationship between radioactive wastes and human life through groundwater, i.e. nuclide migration. In Chapter V is made a reference case which characterizes the geological environmental data using artificial barrier specifications. (Ohno. S.)

290

Formation of extracellular glutamate from glutamine: exclusion of pyroglutamate as an intermediate.  

A 4.6-fold increase in interstitial glutamate was observed following the reverse microdialysis of 5 mM glutamine into the rat hippocampus. Two possible mechanisms of glutamine hydrolysis were examined: (a) an enzymatic glutaminase activity and (b) a non-enzymatic mechanism. Injection of 14C-glutamine at the site of microdialysis followed by microdialysis with artificial cerebral spinal fluid allowed isolation of 14C-glutamine (63%), 14C-glutamate (14%), and a compound tentatively identified as pyroglutamate (22%). In this study, we determined if non-enzymatic pyroglutamate formation from glutamine contributed to the synthesis of glutamate. Pyroglutamate is in chemical equilibrium with glutamate, although under physiological conditions, the chemical equilibrium is strongly in the direction of pyroglutamate. In vitro stability studies indicated that 14C-glutamine and 14C-pyroglutamate are not subject to significant non-enzymatic breakdown at pH 6.5-7.5 at 37 degrees C for up to 8 h. Reverse microdialysis with 1 mM pyroglutamate did not increase interstitial glutamate levels. Following injection of 14C-pyroglutamate and microdialysis, radioactivity was recovered in 14C-pyroglutamate (88%) and 14C-glutamine (11%). Less than 1% of the radioactivity was recovered as glutamate. Our data do not support a role of pyroglutamate as an intermediate in the formation of extracellular glutamate following the infusion of glutamine. However, it confirms that pyroglutamate, a known constituent in brain, is actively metabolized in brain cells and contributes to glutamine in the interstitial space. PMID:16004974

291

The Impact of Partitioning and Transmutation on the Risk Assesment of a Spent Nuclear Fuel  

Partitioning and transmutation of radioactive and long lived component from the highly radioactive waste stream in order to reduce or probably eliminate their radiotoxic inventory was the important option for the nuclear waste management. The principal radionuclides contribution to the long term radiotoxic inventory is mostly due to Pu, minor actinides and some long-lived fission products. The conditioning operation can present artificial barriers which are potentially capable of confining the radionuclides within their package for thousands of years. After this time nothing can be predicted. The solubility of the actinides (except Np) is generally low whereas the long lived fission product. particularly {sup 137}Cs, {sup 129}I and in some case {sup 99}Tc, display high mobility In the geosphere. Conditioning of separated long-lived nuclides in appropriate matrices which could serve as irradiation matrix in a delayed transmutation option is a possible outcome for the next decades. The general strategy of introducing Partitioning and Transmutation as an additional waste management option is based on the radiological benefit which is expected from such an option. The short term impact of partitioning would be to reduce long-term radiotoxic inventory of the resulting HLW at the expense of an increase of the operational requirements for the nuclear facilities concerned. Fast neutron spectrum devices (FR or ADS facilities) are more efficient than current LWRs for recycling and transmuting long-lived radionuclides.

292

Long-Distance Radionuclide Transfer in the Arctic Seas Related to Fish Migrations  

The long-distance migrations of commercial fish in the arctic seas may lead to the biological transfer of artificial radionuclides from highly contaminated local zones in the arctic seas to remote non-contaminated areas. Based on experimental data the dynamics of {sup 137}Cs bioaccumulation in fish from the Barents Sea (arcto-norwegian cod) was analysed. It was demonstrated that the {sup 137}Cs concentration factors for arctic fish were not constant, but gradually changed from 28 {+-} 5 in 1979 up to 182 {+-} 48 in 1992 with a slow decrease in subsequent years. The conclusion reached was that the radionuclide 'concentration factor' approach to the prediction of arctic fish contamination was not very applicable. An original calculation method is proposed for modelling the dynamics of radioactive contamination of fish, with consideration of fish feeding behaviour, growth and seasonal migrations. Results of the computer simulation of the fish contamination in the Barents Sea after a hypothetical accidental release of 1 TBq of {sup 137}Cs from the radioactive waste dumping site are presented. (author)

293

{sup 137}Cs inventory in sedimentary columns from continental shelf of Sao Paulo state  

{sup 137}Cs is an artificial radioactive isotope produced by {sup 235}U fission. This radionuclide has a high fission yield and a half-life of 30 years. It has been detected in the environment since 1945 and its principal contamination source has been nuclear tests in the atmosphere. There are other sources of {sup 137}Cs contamination in the environment, such as: release from nuclear and reprocessing plants, radioactive dumping and nuclear accidents (Chernobyl, for example). This paper presents an inventory of {sup 137}Cs on the Continental Shelf of Sao Paulo State, a region located between Cabo de Santa Marta Grande (Santa Catarina state) and Cabo Frio (Rio de Janeiro state). In this area, 9 cores were collected by the Instituto Oceanografico da Universidade de Sao Paulo (Sao Paulo University Institute of Oceanography). The cores were sliced at every 2 cm; sub-samples were lyophilized, grinded and stored in plastic containers. {sup 137}Cs was determined by 661 keV photopeak using a gamma spectrometry detector (Ge hyperpure). The analysis was performed by efficiency and background in different counting times. {sup 137}Cs concentration activities varied from 0.3 to 3.6 Bq kg{sup -1} with a mean value of 1.2+-0.6 Bq kg{sup -1}. The inventory of {sup 137}Cs in this area was 13+-7 Bq m-2. Values obtained are in agreement with the Southern Hemisphere, a region contaminated by atmospheric fallout due to past nuclear explosions. (author)

294

The implications of particle energy and acidic media on gross alpha and gross beta determination using liquid scintillation.  

The interaction of humans with radioactivity present in the environment from natural and artificial sources necessitates an evaluation of its risk on human health. Gross alpha and gross beta activities can provide a rapid evaluation of the radioactive content of a sample and can be simultaneously determined by using liquid scintillation counters. However, calibration of the liquid scintillation counter is required and is affected by many factors, such as particle energy and the acidity of the media. This study investigates what effect the particle energy used for calibration has on misclassification and how to account for this misclassification in routine measurements. The variability in measurement produced by the final pH, as well as any acids used in sample treatment, was also studied. These results showed that the most commonly used acid for these types of analyses, HNO(3), produced a high amount of misclassifications at very low pH. The results improved when HCl was used to adjust the sample to low pH. PMID:22200448

295

FIELD TESTS USING RADIOACTIVE MATTER 2.  

Results of field tests with explosive dispersal of a radioactive substance (RaS) are presented. The paper deals with tests exploiting artificial obstacles as a continuation and expansion of the tests used in this study performed in free area described previously. The essential goal of the tests was to estimate the distribution of the released RaS in the case of intentional abuse of radioactive sources and to get a set of data applicable to testing physical or mathematical models of propagation. Effects of different geometrical and meteorological conditions on the distribution of dispersed RaS were studied via the assessment of dose rate, surface and volume activities, aerosol mass and activity aerodynamic diameters. The principal results can be summarised as follows: the prevalent proportion of the activity of the radionuclide dispersed by an explosion (born by the blast wave and by air convection) is transferred to the detection system/collecting pads essentially within the first minute. Enhanced aerosol mass concentrations were also detected within the same period. The RaS carried by the blast wave passed through the polygon (50 m) within <1 s. An expected crucial impact of meteorological conditions at the moment of the explosion and shortly after was proved by the tests. PMID:22923250

296

Measurement of tritiated norepinephrine metabolism in intact rat brain  

A procedure for the study of NE metabolism in the intact rat brain is described. The method involves ventriculocisternal perfusion of the adult male rat with artificial CSF containing (/sup 3/H)NE. Radioactivity in the perfusate associated with NE and its metabolites 3,4-dihydroxymandelic acid (DOMA), 3,4-dihydroxphenylethyleneglycol (DHPG), 3-methoxy-4-hydroxymandelic acid (VMA), 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG), and normetanephrine (NMN) is separated using high-performance liquid chromatography (HPLC). After 80 min the radioactivity in the perfusate reaches an apparent steady-state. Analysis of the steady-state samples shows higher activity in the fractions corresponding to DHPG and MHPG than in those corresponding to DOMA and VMA, confirming glycol formation as the major pathway of NE metabolism in the rat brain. Pretreatment with an MAO inhibitor (tranylcypromine) results in a marked decrease in the deaminated metabolites DHPG and MHPG and a concurrent increase in NMN. The results indicate this to be a sensitive procedure for the in vivo determination of changes in NE metabolism.

297

Functional remineralization of dentin lesions using polymer-induced liquid-precursor process.  

It was hypothesized that applying the polymer-induced liquid-precursor (PILP) system to artificial lesions would result in time-dependent functional remineralization of carious dentin lesions that restores the mechanical properties of demineralized dentin matrix. 140 µm deep artificial caries lesions were remineralized via the PILP process for 7-28 days at 37°C to determine temporal remineralization characteristics. Poly-L-aspartic acid (27 KDa) was used as the polymeric process-directing agent and was added to the remineralization solution at a calcium-to-phosphate ratio of 2.14 (mol/mol). Nanomechanical properties of hydrated artificial lesions had a low reduced elastic modulus (E(R) = 0.2 GPa) region extending about 70 ?m into the lesion, with a sloped region to about 140 ?m where values reached normal dentin (18-20 GPa). After 7 days specimens recovered mechanical properties in the sloped region by 51% compared to the artificial lesion. Between 7-14 days, recovery of the outer portion of the lesion continued to a level of about 10 GPa with 74% improvement. 28 days of PILP mineralization resulted in 91% improvement of E(R) compared to the artificial lesion. These differences were statistically significant as determined from change-point diagrams. Mineral profiles determined by micro x-ray computed tomography were shallower than those determined by nanoindentation, and showed similar changes over time, but full mineral recovery occurred after 14 days in both the outer and sloped portions of the lesion. Scanning electron microscopy and energy dispersive x-ray analysis showed similar morphologies that were distinct from normal dentin with a clear line of demarcation between the outer and sloped portions of the lesion. Transmission electron microscopy and selected area electron diffraction showed that the starting lesions contained some residual mineral in the outer portions, which exhibited poor crystallinity. During remineralization, intrafibrillar mineral increased and crystallinity improved with intrafibrillar mineral exhibiting the orientation found in normal dentin or bone. PMID:22719965

298

Genetically Controlled Fusion, Exocytosis and Fission of Artificial Vesicles  

Artificial vesicles represent ideal candidates as a model for artificial cells. It was shown that artificial genetic programs and the required cellular machinery (cell-free expression systems) can be incorporated into vesicles and allow the synthesis of proteins. Vesicles were shown to fuse if a special class of viral proteins, termed fusogenic peptides, were added to the external medium. In the present work, we intend to develop genetically controlled fusion, fission and exocytosis of vesicles by the synthesis of peptides within vesicles. First, we enclosed synthesized peptides in vesicles to induce in a next step fusion of adjacent vesicles, fission and exocytosis of nested vesicles. Second, we will replace the peptides by an enclosed cell-free expression system to internally synthesize fusion peptides. To control the gene expression, different mechanisms are available, e.g. addition of transcription factors. Changes in the pH are reported to control the activity of the fusion peptides. So far, we successfully enclosed a commercially available cell-free system and expressed eGFP in vesicles as a proof of principle. Furthermore, we optimized the already established protocol to produce nested vesicles in the presence of peptides. This project may present a step towards personalized drug delivery. Specific drugs or prodrugs enclosed into vesicles may be released upon an external signal related to a disease, e.g. a tumor, to activate gene expression and synthesis of fusion peptides to induce fusion, fission and exocytosis.

299

Analysis of natural and artificial ultramarine blue pigments using laser induced breakdown and pulsed Raman spectroscopy, statistical analysis and light microscopy.  

Pulsed laser induced breakdown spectroscopy (LIBS) and Raman spectroscopy were performed using a novel laboratory setup employing the same Nd:YAG laser emission at 532 nm for the analysis of five commercially available pigments collectively known as "ultramarine blue", a sodium silicate material of either mineral origin or an artificially produced glass. LIBS and Raman spectroscopy have provided information regarding the elemental and molecular composition of the samples; additionally, an analytical protocol for the differentiation between natural (lapis lazuli) and artificial ultramarine blue pigments is proposed. In particular LIBS analysis has allowed the discrimination between pigments on the basis of peaks ascribed to calcium. The presence of calcite in the natural blue pigments has been confirmed following Raman spectroscopy in specific areas of the samples, and micro-Raman and optical microscopy have further corroborated the presence of calcite inclusions in the samples of natural origin. Finally multivariate analysis of Laser induced breakdown spectra using principal component analysis (PCA) further enhanced the differentiation between natural and artificial ultramarine blue pigments. PMID:19129003

300

The bio-positive effects of burned radioactive lantern mantle powder on the wound healing in rats  

Objective: Poor educated people in some parts of Iran use burned mantles as a wound healing powder to prevent the two main threats with the injuries, bleeding and the infection. Some lantern mantles contain low levels of radioactive thorium for maximizing the light output, while non-radioactive mantles contain yttrium. Although radioactive lantern mantles present a minimal radiation health hazard, it is generally believed when inhaled or ingested, thorium containing mantle powder, will be dangerous. To evaluate the effect of burned radioactive lantern mantles on wound healing this study was conducted. Materials and Methods: Twenty rats were divided randomly into two groups of 10 animals each. After inducing general anesthesia, full thickness excision wound was made on the dorsal neck in all animals. The 1. group received topical burned radioactive lantern mantle powder at 1-3 day after making excision wounds. The 2. group received non-radioactive lantern mantle powder at the same days. Accurate blind surface measurement of the wounds by transparency tracing was used for assessment of the wound healing at 1, 3, 7, 10 and 15 days after making wounds. Results: Surface area measurement of the wounds showed a progressive surface reduction in both groups. However, for thorium treated group, the rate of recovery was significantly enhanced compared to that of the control group. Although the wound area in the thorium group was not significantly different from that of the control group at the 3. and 5. days after wounding, a statistically significant difference was observed between the thorium and the control groups at the day 7, day 10 and day 15. The mean wound surface in thorium and control groups were 150.20{+-}15.87 and 186.37{+-}12.68 mm{sup 2} at day 7 (P<0.001), 92.90{+-}15.97 and 134.12{+-}14.19 mm{sup 2} at day 10 (P<0.001), 1.4{+-}0.41 and 8.56{+-}2.04 mm{sup 2} at day 15 after wounding, respectively (P<0.01) Conclusions: These findings suggest that low-level radioactive burned mantle accelerates wound healing in rats. However, as thorium oxide is a known human carcinogen, more research is needed to clarify if low levels of radioactive burned mantle can be utilized for accelerating the healing of human wounds. (authors)

 
 
 
 
301

Design, calibration, and application of an airborne gamma spectrometer system in Switzerland  

Airborne radiometric surveys are finding increasingly wider application in environmental mapping and monitoring. They are the most efficient tool to delimit surface contamination and to locate lost radioactive sources. To secure radiometric capability in survey and emergency situations, a new sensitive airborne system has been built that includes an airborne spectrometer with 256 channels and a sodium iodide detector with a total volume of 16.8 liters. A rack-mounted PC with memory cards is used for data acquisition, with a GPS satellite navigation system for positioning. The system was calibrated with point sources using a mathematical correction to take into account the effects of gamma-ray scattering in the ground and in the atmosphere. The calibration was complemented by high precision ground gamma spectrometry and laboratory measurements on rock samples. In Switzerland, two major research programs make use of the capabilities of airborne radiometric measurements. The first one concerns nuclear power-plant monitoring. The five Swiss nuclear installations (four power plants and one research facility) and the surrounding regions of each site are surveyed annually. The project goal is to monitor the dose-rate distribution and to provide a documented baseline database. The measurements show that all sites (with the exception of the Goesgen power plant) can be identified clearly on the maps. No artificial radioactivity that could not be explained by the Chernobyl release or earlier nuclear weapons tests was detected outside of the fenced sites of the nuclear installations. The second program aims at a better evaluation of the natural radiation level in Switzerland. The survey focused on the crystalline rocks of the Central Massifs of the Swiss Alps because of their relatively high natural radioactivity and lithological variability.

302

Peace programme for evaluating the impact of accidents contaminating the environment  

The Chernobyl accident, which led to substantial release of radioactive materials in the atmosphere, demonstrated that large environmental areas may be contaminated by fall-out deposition of radioactivity. In particular, contamination by Cs and Sr of agro-ecosystems where food production is taking place is most susceptible to contribute to population radiation dose. Nuclear safety analysis shows that, although very small, the probability of an accident occurring on a pressurized water reactor (PWR) cannot be completely set aside. In such a situation, decision making and management of the contaminated agricultural surfaces largely depend on our ability to predict how, and to which extent, the initial contamination may lead to polluted foodstuffs. Furthermore, the efficiency of the prediction models relies on our level of understanding of the mechanisms governing the transfer of radionuclides in the soil-plant system. Unraveling these mechanisms from in situ observations of environmental areas contaminated by past events is difficult due to the lack of control on both, the contamination itself, which happened in a critical situation, and the natural environment, which is highly variable, temporally and spatially. Such conditions prevent a clear identification of the most relevant parameters influencing the radionuclides transfer and thereby the prediction goal. In particular, current transfer factors introduced in prediction models suffer from unresolved and poorly documented variabilities. This is why IPSN developed a unique research facility capable of generating, in closed and controlled environmental conditions, a mini-accident with release of radioactive aerosols on small-scale, but realistic, samples of crops. These crops are conducted on undisturbed soil monoliths, featuring several soil types from various European countries, managed in lysimeters with advanced water movement control, and placed in greenhouses where three typical climates can be reproduced artificially, and yearly repeated, by means of computer control. (author)

303

Radioactive contamination in the marine environment. Report No. 2 from the national surveillance programme  

During 1995 and 1996 a large number of samples of different types, collected from various fishing grounds of interest for Norwegian commercial fishing, were measured. During these years 50 pooled fish samples from a total of 2525 fish have been measured for gamma emitting radionuclides. Of these eight samples have also been measured for plutoniumisotopes. Thirteen samples of shrimps have also been measured for various radionuclides. In addition 800 samples of fish have been measured for radiocaesium on routine monitoring equipment with higher detection limit. For all those samples the content of radiocaesium fell below the detection limit. The general levels of radioactive contamination in the ocean areas surrounding Norway are low. In fish and shrimps the concentration of {sup 137}Cs is in the order of 1 Bq/kg. This is in the same range as the lowest levels found in products from the terrestrial ecosystem and far below the intervention levels for radioactive contamination of foodstuff. For most of the samples of biota measured for plutonium, the level fell below the limit of detection, a maximum of 5.6 mBq/kg og alpha emitting plutonium isotopes was found. Measurements on a number of samples of seawater, sediments and seaweed further confirms the low levels of radioactive contamination in the North Sea, the Norwegian Sea and the Barents Sea. For biota the levels of concerned radionuclides were decreasing towards north. This is due to the main sources of artificial radionuclides being located south of Norway, in the Baltic (Chernobyl fallout) and in the Irish Sea (Sellafield releases). 18 refs., 4 figs., 5 tabs.

304

Determination of the isotopic ratio {sup 234} U/{sup 238} U and {sup 235} U/{sup 238} U in uranium commercial reagents by alpha spectroscopy; Determinacion de la relacion isotopica {sup 234} U/{sup 238} U y {sup 235} U/{sup 238} U en reactivos comerciales de uranio por espectrometria alfa  

In this work the determination of the isotope ratio {sup 234} U/{sup 238} U and {sup 235} U/{sup 238} U obtained by means of the alpha spectroscopy technique in uranium reagents of commercial marks is presented. The analyzed uranium reagents were: UO{sub 2} (*) nuclear purity, UO{sub 3} (*) poly-science, metallic uranium, uranyl nitrate and uranyl acetate Merck, uranyl acetate and uranyl nitrate Baker, uranyl nitrate (*) of the Refinement and Conversion Department of the ININ, uranyl acetate (*) Medi-Lab Sigma of Mexico and uranyl nitrate Em Science. The obtained results show that the reagents that are suitable with asterisk (*) are in radioactive balance among the one {sup 234} U/{sup 238} U, since the obtained value went near to the unit. In the case of the isotope ratio {sup 235} U/{sup 238} U the near value was also obtained the one that marks the literature that is to say 0.04347, what indicates that these reagents contain the isotope of {sup 235} U in the percentage found in the nature of 0.71%. The other reagents are in radioactive imbalance among the {sup 234} U/{sup 238} U, the found values fluctuated between 0.4187 and 0.1677, and for the quotient of activities {sup 235} U/{sup 238} U its were of 0.0226, and the lowest of 0.01084. Also in these reagents it was at the {sup 236} U as impurity. The isotope of {sup 236} U is an isotope produced artificially, for what is supposed that the reagents that are in radioactive imbalance were synthesized starting from irradiated fuel. (Author)

305

A behavioral perspective on fishing-induced evolution.  

The potential for excessive and/or selective fishing to act as an evolutionary force has been emphasized recently. However, most studies have focused on evolution of life-history traits in response to size-selective harvesting. Here we draw attention to fishing-induced evolution of behavioral and underlying physiological traits. We contend that fishing-induced selection directly acting on behavioral rather than on life-history traits per se can be expected in all fisheries that operate with passive gears such as trapping, angling and gill-netting. Recent artificial selection experiments in the nest-guarding largemouth bass Micropterus salmoides suggest that fishing-induced evolution of behavioral traits that reduce exposure to fishing gear might be maladaptive, potentially reducing natural recruitment. To improve understanding and management of fisheries-induced evolution, we encourage greater application of methods from behavioral ecology, physiological ecology and behavioral genetics. PMID:18582988

306

Triple-band polarization-insensitive wide-angle ultra-miniature metamaterial transmission line absorber  

We report on the design, fabrication, and measurement of a triple-band absorber enhanced from a planar two-dimensional artificial metamaterial transmission line (TL) concept. Unlike previous multiband absorbers, this implementation incorporates fractal geometry into the artificial TL framework. As a consequence of the formed large LC values, the utilized element is compact in size, which approaches ?0/15 at the lowest fundamental resonant frequency. For independent control and design, a theoretical characterization based on a circuit model analysis (TL theory) is performed and a set of design procedures is also derived. Both numerical and experimental results have validated three strong absorption peaks across the S, C, and X bands, respectively, which are attributable to a series of self-resonances induced in the specific localized area. The absorber features near-unity absorption for a wide range of incident angles and polarization states and a great degree of design flexibility by manipulating the LC values in a straightforward way.

307

Cyclical changes of plasma sex steroids in captive breeding loggerhead turtles (Caretta caretta).  

Loggerhead turtles (Caretta caretta) have been laying eggs in an indoor artificial beach since 1995, at the Port of Nagoya Public Aquarium (PNPA). Four individuals landed and laid eggs several times during the breeding period in 1996. Blood samples from these individuals were collected monthly throughout that year in order to investigate the changes in sex steroid hormones (testosterone, estradiol, and progesterone). In addition, detailed investigations were conducted daily during the breeding period on one particular individual that landed and laid eggs five times in 1998. Each steroid hormone changed periodically based on the laying cycle, and extraordinarily high levels of estradiol were noted even during the breeding period. In reports regarding the green turtle (Chelonia mydas), extremely different results were observed. Some of the obtained data suggest that progesterone induced ovulation. Data from a completely artificial environment such as the one at the PNPA provides elucidation of the reproductive physiology in these endangered species. PMID:21370645

308

Photosynthetic responses of field-grown Pinus radiata trees to artificial and aphid-induced defoliation  

The phloem-feeding aphid Essigella californica represents a potential threat to the productivity of Pinus radiata plantations in south-eastern Australia. Five- and nine-year-old field trials were used to characterize the effects of artificial and natural aphid-induced (E. californica) defoliation, respectively, on shoot photosynthesis and growth. Photosynthetic capacity (Amax) was significantly greater following a 25% (D25) (13.8 mol m-2 s-1) and a 50% (D50) (15.9 mol m-2 s-1) single-event upper-crown artificial defoliation, 3 weeks after defoliation than in undefoliated control trees (12.9 mol m-2 s-1). This response was consistently observed for up to 11 weeks after the defoliation event; by Week 16, there was no difference in Amax between control and defoliated trees. In the D50 treatme...

309

The Single-Photon Router  

We have embedded an artificial atom, a superconducting "transmon" qubit, in an open transmission line and investigated the strong scattering of incident microwave photons ($\\sim6$ GHz). When an input coherent state, with an average photon number $N\\ll1$ is on resonance with the artificial atom, we observe extinction of up to 90% in the forward propagating field. We use two-tone spectroscopy to study scattering from excited states and we observe electromagnetically induced transparency (EIT). We then use EIT to make a single-photon router, where we can control to what output port an incoming signal is delivered. The maximum on-off ratio is around 90% with a rise and fall time on the order of nanoseconds, consistent with theoretical expectations. The router can easily be extended to have multiple output ports and it can be viewed as a rudimentary quantum node, an important step towards building quantum information networks.

310

Biomaterials and inorganic-organic composites; Seitai zairyo to muki-yuki fukugoka  

Hard structure materials such as artificial bones are demanded currently of characteristics to harmonize with human life activities. What is required particularly is such characteristics that the materials change into bones naturally in a human body, and induce necessary structures by activating cells. Biomaterials having such high functions are expected to be realized by making a hybrid of inorganic materials such as our bones and teeth and organic materials. However, compounding inorganic materials with organic materials is not an easy work. Therefore, the great barrier is the fabrication techniques of the composites. This paper introduces one of the approaches to techniques to compound inorganic materials with organic materials. A composite of collagen with apatite is thought a material having the highest possibility as a biologically active artificial bone. Electron microscopic observation and spectroscopic measurement avail an estimation that chemical bonding is executed between biological polymers and apatite crystals, and the bonding is related with self-structuring of bones. 2 refs., 7 figs.

311

Burst test of a vessel under wet sour gas conditions  

A sour burst test of a pressure vessel is described and the results given. The vessel was inspected for existing defects, material properties tested, integrity analyzed and artificial defects introduced before the vessel was subjected to a worst-case environment causing hydrogen charging. The vessel had existing hydrogen-induced cracking (HIC) and some vertical weld defects. Laboratory materials testing in the hydrogen-charging environment showed the vessel was susceptible to HIC damage, showed no yield strength reduction, reduced plastic ductility in rising load but exhibited a brittleness under high plastic strain. No existing or artificial defect initialed the final burst. Sulfide stress cracking (SSC) initiated at a weld produced with temper-bead capping passes but no post weld heat treatment. The vessel survived to 1.2 times actual yield or more than four times its license pressure but the vessel did exhibit a decrease in plastic ductility. Monitoring during the burst test showed that the vessel had been significantly charged with hydrogen.

312

Artificial Propagation of a Small Endangered Cyprinid, Golden Venus Chub Hemigrammocypris rasborella Fowler  

Rearing conditions for larvae and juveniles, including induction of spawning by human chorionic gonadotropin (HCG) were examined to establish a way of artificial propagation for endangered fish golden venus chub, Hemigrammocypris rasborella. Gonads of parental fishes were developed in six months by keeping water temperature in 27±1°C and long photoperiod treatment in 14L-10D. In order to induce the spawning, matured fish were administered by HCG at 5 IU/gBW to males, and 10 IU/gBW to females, and released into a tank with spawning bed. Incidentally, spawning was observed between 8-10 h after HCG injection. The total number of collected eggs is 1710, of which 768 hatched. It was clarified that mixture of green water and artificial feed were well efficient as early feed to growth and development of the larvae and juveniles. They rapidly grew till 120 days after hatching, after then more slowly in rearing condition 27±1°C.   

313

The effect of plum juice on the prevention of struvite calculus formation in vitro  

OBJECTIVES -- To evaluate the effect of plum juice on struvite calculus formation in vitro and to explore the effect of plum juice on urease-producing bacteria and urease activity -- The compliance of available drugs is low for struvite calculus after surgical treatment and functional food may represent a good choice as an alternative therapy. MATERIALS AND METHODS -- Antibacterial activity was assessed using a microdilution antimicrobial susceptibility test. -- Urease activity was determined by measuring ammonia production. -- Struvite crystals were induced by Proteus mirabilis in artificial urine with natural and pH-adjusted plum juice. -- The optical density (OD)600 and pH of artificial urine were examined, as well the shape and weights of crystals. RESULTS -- Natural plum juice showed ...

314

Increasing the wear resistance of UHMWPE acetabular cups by adding natural biocompatible particles  

Ultra-high molecular weight polyethylene (UHMWPE) is a kind of biomaterial applied as the acetabular cup in artificial hip joints. However, wear debris generation of UHMWPE materials after their replacements in human body has been proved to induce aseptic loosening and osteolysis, which is the main cause of long-term failure of total hip joints composed of UHMWPE and hard femoral balls. In this paper, natural coral (NC) particles in the size within 50mm were applied as reinforcement fillers into UHMWPE to increase the wear resistance of UHMWPE composites as artificial acetabular cups. The micro-hardness and scratch resistance of UHMWPE/NC composites were studied. A hip joint wear simulator was operated to investigate the wear behavior of UHMWPE/NC composites against CoCrMo balls, the wear ...

315

Magnetoelastic metamaterials  

The study of advanced artificial electromagnetic materials, known as metamaterials, provides a link from material science to theoretical and applied electrodynamics, as well as to electrical engineering. Being initially intended mainly to achieve negative refraction, the concept of metamaterials quickly covered a much broader range of applications, from microwaves to optics and even acoustics. In particular, nonlinear metamaterials established a new research direction giving rise to fruitful ideas for tunable and active artificial materials. Here we introduce the concept of magnetoelastic metamaterials, where a new type of nonlinear response emerges from mutual interaction. This is achieved by providing a mechanical degree of freedom so that the electromagnetic interaction in the metamaterial lattice is coupled to elastic interaction. This enables the electromagnetically induced forces to change the metamaterial structure, dynamically tuning its effective properties. This concept leads to a new generation of metamaterials, and can be compared to such fundamental concepts of modern physics as optomechanics of photonic structures or magnetoelasticity in magnetic materials.

316

Spent fuel cladding containment credit tests  

Preliminary tests are being conducted to evaluate the effectiveness of defected cladding as a barrier to radionuclide release from spent fuel rods stored in a geological repository. The tests are being conducted at the Hanford Engineering Development Laboratory Waste Package Task of the Nevada Nuclear Waste Storage Investigations (NNWSI) tuff repository project. In these tests, spent PWR fuel rod specimens with various artificially induced cladding defects are leach tested in a test matrix which also includes both bare fuel specimens (unclad) and undefected spent fuel rod specimens. Artificial cladding defects are made by laser drilling and sawing to give defect areas in the 10{sup 4} to 10{sup 6} {mu}m{sup 2} range. Periodic samples are taken of the leach solution and fused quartz rods contained in the test vessels. Results for the first 180 days of testing are presented. 5 references, 3 figures, 2 tables.

317

Single and joint effects of HHCB and cadmium on zebrafish (Danio rerio) in feculent water containing bedloads  

As an important type of emerging pollutants, ecological toxicity and risk of artificial musks are increasingly concerned. Thus, single and joint toxic effects of 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-gamma-2-benzopyr an (HHCB) as one of the most widely applied artificial musks and cadmium (Cd) as an toxic metal on zebrafish (Danio rerio) were investigated by the exposure of zebrafish to various concentrations of HHCB or/and Cd in feculent water containing bedloads. The results indicated that the joint effect of HHCB and Cd changed during different exposure times within 120 h. The index of the antioxidant enzyme system including superoxide dismutase (SOD) and peroxidase (POD), and malondialdehyde (MDA) were sensitive and induced in the zebrafish stressed by Cd, and content ...

318

Ketorolac inhibits choroidal neovascularization by suppression of retinal VEGF  

We assessed the effect of topical ketorolac on laser-induced choroidal neovascularization (CNV), measured retinal PGE2 and VEGF levels after laser treatment, and determined the effect of ketorolac on PGE2 and VEGF production. Six laser burns were placed in eyes of rats which then received topical ketorolac 0.4% or artificial tears four times daily until sacrifice. Fluorescein angiography (FA) was performed at 2 and 3 weeks and retinal pigment epithelium-choroid-sclera flat mounts were prepared. The retina and vitreous were isolated at 1, 3, 5, 7, and 14 days after laser treatment and tested for VEGF and PGE2. Additional animals were lasered and treated with topical ketorolac or artificial tears and tested at 3 and 7 days for retinal and vitreous VEGF and PGE2. Ketorolac reduced CNV on FA b...

319

Analysis of natural and artificial ultramarine blue pigments using laser induced breakdown and pulsed Raman spectroscopy, statistical analysis and light microscopy  

Pulsed laser induced breakdown spectroscopy (LIBS) and Raman spectroscopy were performed using a novel laboratory setup employing the same Nd:YAG laser emission at 532nm for the analysis of five commercially available pigments collectively known as "ultramarine blue", a sodium silicate material of either mineral origin or an artificially produced glass. LIBS and Raman spectroscopy have provided information regarding the elemental and molecular composition of the samples; additionally, an analytical protocol for the differentiation between natural (lapis lazuli) and artificial ultramarine blue pigments is proposed. In particular LIBS analysis has allowed the discrimination between pigments on the basis of peaks ascribed to calcium. The presence of calcite in the natural blue pigments has be...

320

Construction of a Rhizopus arrhizus glucoamylase gene suitable for expression in distinct host: introns spliced artificially by PCR  

Glucoamylase is an industrially extremely important enzyme in the fermentative production of ethanol, used in the enzymatic conversion of starch into high glucose and fructose syrups. The aim of this study is to construct a Rhizopus arrhizus glucoamylase gene (RaGA)?introns artificially spliced by PCR?suitable for expression in S. cerevisiae host and tried expressing in Picha pastoris. In previous work, we failed in amplifying glucoamylase gene from R. arrhizus by RT-PCR, so several primers were designed to splicing the introns by PCR in vitro. Sequence analysis shown that all introns in the RaGA were deleted correctly and no mutant was induced in the extrons compared with the RaGA gene originally cloned. The RaGA gene artificially constructed was transferred into P. pastoris integrative e...

 
 
 
 
321

Autologous urothelial cells transplantation onto a prefabricated capsular stent for tissue engineered ureteral reconstruction  

In this study, we have fabricated an artificial ureter by transplantation of in vitro-expanded urothelial cells onto an in vivo-prefabricated capsular stent using tissue engineering methods. Spiral poly (l-lactic acid) (PLLA) stents were transplanted into the subcutaneous of Wistar rats for a period of 1, 2 or 3?weeks to induce the formation of connective tissue capsules on their surfaces. The capsular PLLA stents were then decellularized and further recellularized with bladder epithelial cells to fabricate artificial ureters. The results showed that the entrapped cells in all capsules remained continuously proliferation and lined up in continuous layers. In addition, the urothelial cells on the capsular stents with an embedding period of 2 or 3?weeks showed higher proliferative viability ...

322

Preparation and characterization of a VEGF-Fc fusion protein matrix for enhancing HUVEC growth.  

To enhance vascularization of hydrophobic implants in vivo, a VEGF-Fc fusion protein consisting of vascular endothelial growth factor (VEGF) fused to the immunoglobulin G Fc domain was prepared as an artificial extracellular matrix (ECM). VEGF-Fc was stably immobilized on a polystyrene plate due to the hydrophobicity of the Fc domain, and significantly enhanced the adhesion of human umbilical vein endothelial cells (HUVECs). Additionally, the use of VEGF-Fc as an ECM markedly promoted the proliferation of HUVECs longer than 72 h and induced the reorganization of actin filaments into larger stress fibers within these cells. The VEGF-Fc fusion protein may be a promising artificial ECM for enhancing endothelial cell growth. PMID:22661013

323

Evaluation of radiation exposure from a consumer product. A pillow  

Radiation exposure from a pillow was analyzed. According to an advertisement of the pillow, this radioactive consumer product contains enough amounts of radioactive materials to induce radiation hormesis effects. The pillow consists of the filling chips made from kneading mineral ores and the polynosic linings contains natural radioactive ores. A {gamma}-ray analysis of the pillow using pure Ge-MCA reveals that there exist radioactivities of thorium and uranium series mixtures in it at concentration of 0.58% by the weight. The observations of a chip surface by a scanning electron microscope show that the shapes of two sides are different each other. There are lots of sharp protuberances on the outside of the chip. To determine the direct external exposures from the pillow, film badges were placed on the pillow for 210 h and 2555 h. The dose equivalents of 210 h exposure was under 0.1 mSv which is a detection limit of a {gamma}-ray by the film badges. However, that of 2555 h exposure was over 0.1 mSv less than 0.15 mSv. Quantities of internal exposures from inhalation of the vaporized Rn were measured by a Lucas Cell. It was 79 Bq/m{sup 3}. There is no necessity for anxious about being broken in health inhaling the Rn-gass. (author)

324

Radioactivity and foods  

The purpose of this article is to describe and contrast two relationships between radiation and food--on the one hand, beneficial preservation of food by controlled exposure to ionizing radiation; and, on the other, contamination of food by accidental incorporation of radioactive nuclides within the food itself. In food irradiation, electrons or electromagnetic radiation is used to destroy microorganisms and insects or prevent seed germination. The economic advantages and health benefits of sterilizing food in this manner are clear, and numerous studies have confirmed that under strictly controlled conditions no undersirable changes or induced radioactivity is produced in the irradiated food. An altogether different situation is presented by exposure of food animals and farming areas to radioactive materials, as occurred after the major Soviet nuclear reactor accident at Chenobyl. This article furnishes the basic information needed to understand the nature of food contamination associated with that event and describes the work of international organizations seeking to establish appropriate safe limits for levels of radioactivity in foods.

325

Study of the alkaline cations complexation by photo-isomerizable calixarenes; Etude de la complexation de cations alcalins par des calixarenes photoisomerisables  

The first step to reduce the volume and the toxicity of radioactive waste coming from the spent fuel reprocessing is to separate long life radioisotopes from others ones with a shorter period. The aim of this study is to show that the control of the two phenomenons, complexation of the cation by the calixarenes and its de-complexation, can be envisaged by the introduction on the molecule of a chromophore group, azo benzene, able to modify the complexing site structure of the calixarenes with an isomerization trans-cis induced by ultraviolet radiation, and isomerization cis-trans thermally induced by a visible radiation. (N.C.). 112 refs., 78 figs., 23 tabs.

326

Radiation nephritis and anaemia: a functional assay for renal damage after irradiation  

In the course of using a /sup 51/Cr-EDTA clearance assay, the authors observed that a complication of this method was the anaemia which has long been known to accompany renal insufficiency in man and other species, whether the nephropathy is radiation-induced or from other causes. During the present studies it became clear that /sup 51/Cr-EDTA clearance measurements should be based on the measurement of plasma activity rather than whole blood radioactivity. The anaemia was investigated and was found to be an easily quantitated end-point, which increased with increasing X-ray dose, making it in itself a useful tool for studying radiation-induced nephropathy in experimental animals.

327

Artificial neural networks in the evaluation of the radioactive waste drums activity  

The mathematical techniques are becoming more important to solve geometry and standard identification problems. The gamma spectrometry of radioactive waste drums would be a complex solution problem. The main difficulty is the detectors calibration for this geometry; the waste is not homogeneously distributed inside the drums, therefore there are many possible combinations between the activity and the position of these radionuclides inside the drums, making the preparation of calibration standards impracticable. This work describes the development of a methodology to estimate the activity of a 200 L radioactive waste drum, as well as a mapping of the waste distribution, using Artificial Neural Network. The neural network data set entry obtaining was based on the possible detection efficiency combination with 10 sources activities varying from 0 to 74 x 10{sup 3} Bq. The set up consists of a 200 L drum divided in 5 layers. Ten detectors were positioned all the way through a parallel line to the drum axis, from 15 cm of its surface. The Cesium -137 radionuclide source was used. The 50 efficiency obtained values (10 detectors and 5 layers), combined with the 10 source intensities resulted in a 100,000 lines for 15 columns matrix, with all the possible combinations of source intensity and the Cs-137 position in the 5 layers of the drum. This archive was divided in 2 parts to compose the set of training: input and target files. The MatLab 7.0 module of neural networks was used for training. The net architecture has 10 neurons in the input layer, 18 in the hidden layer and 5 in the output layer. The training algorithm was the 'traincgb' and after 300 'epoch s' the medium square error was 0.00108172. This methodology allows knowing the detection positions answers in a heterogeneous distribution of radionuclides inside a 200 L waste drum; in consequence it is possible to estimate the total activity of the drum in the training neural network limits. The results accuracy depends on the way that the waste drum is divided and to the amount of intensities that it is interpolated between the minimum and maximum limits. The use of the Artificial Neural Networks associated to Monte Carlo Method showed to be efficient in the isotopic characterization of radioactive waste drums. (authors)

328

Evaluation of potential induced radioactivity in medical products as a function of electron energy in electron beam sterilization  

Commercial sterilization of medical devices may be performed using electron beam irradiators at various electron energies. The potential for activating components of the devices has been discussed, with current standards stating that electron energy greater than 10 MeV requires assessment of potential induced radioactivity. This paper evaluates the potential for induced activity in medical products sterilized in electron beam as a function of the electron maximum energy. Monte Carlo simulation of a surrogate medical device was used to calculate photon and neutron fields resulting from electron irradiation, which were used to calculate concentrations for several radionuclides.The experiments confirmed that 10 MeV is a conservative assumption for limiting induced radioactivity. However, under the conditions as evaluated, which is a limited total quantity of metal in the material being irradiated and absent a limited number of elements; the amount of induced activity at 12 MeV could also be considered insignificant. The comparison of the sum-of-fractions to the US Nuclear Regulatory Commission exempt concentration limits is less than unity for all energies below 12.1 MeV, which suggests that there is minimal probability of significant induced activity at energies above the 10 MeV upper energy limit.

329

Hormonal regulation and localization of estrogen, progestin and androgen receptors in the endometrium of nonhuman primates: effects of progesterone receptor antagonists  

This article reviews the effects of estradiol (E2), progesterone (P) and P receptor antagonists (PA) on the rhesus macaque endometrium. Ovariectomized macaques can be treated with implants of estradiol (E2) and P to induce precisely controlled, artificial menstrual cycles. During these cycles, treatment with E2 alone induces an artificial proliferative phase marked by extensive endometrial epithelial cell proliferation and increased expression of stromal and epithelial estrogen receptor (ER) and P receptor (PR). Androgen receptor (AR) is also upregulated by E2 but is expressed only by the endometrial stroma. Progesterone acts on the E2 primed endometrium to induce secretory differentiation and causes suppression of epithelial and stromal ER, epithelial PR, and stromal AR in the functionalis zone. However, epithelial ER and PR are retained in the basalis zone during the secretory phase. When potent P antagonists (PA) are administered acutely at the end of an E2+P induced cycle, menses typically ensues similar to P withdrawal at the end of the menstrual cycle. When PAs are administered chronically there is significant blockage of all P- dependent effects including upregulation of ER, PR and AR and suppression of glandular secretory function. However, chronic PA administration also inhibits estrogen-dependent endometrial cell proliferation and growth. This endometrial antiproliferative effect is the basis of the clinical use of PA to control various diseases such as endometriosis.   

330

{gamma}-Globin gene expression in chemical inducer of dimerization (CID)-dependent multipotential cells established from human {beta}-globin locus yeast artificial chromosome ({beta}-YAC) transgenic mice.  

Identification of trans-acting factors or drugs capable of reactivating gamma-globin gene expression is complicated by the lack of suitable cell lines. Human K562 cells co-express epsilon- and gamma-globin but not beta-globin; transgenic mouse erythroleukemia 585 cells express predominantly human beta-globin but also gamma-globin; and transgenic murine GM979 cells co-express human gamma-and beta-globin. Human beta-globin locus yeast artificial chromosome transgenic mice display correct developmental regulation of beta-like globin gene expression. We rationalized that cells established from the adult bone marrow of these mice might express exclusively beta-globin and therefore could be employed to select or screen inducers of gamma-globin expression. A thrombopoietin receptor derivative that brings the proliferative status of primary mouse bone marrow cells under control of a chemical inducer of dimerization was employed to institute and maintain these cell populations. Human beta-globin was expressed, but gamma-globin was not; a similar expression pattern was observed in cells derived from fetal liver. gamma-Globin expression was induced upon exposure to 5-azacytidine, in cells derived from -117 Greek hereditary persistence of fetal hemoglobin human beta-globin locus yeast artificial chromosome (beta-YAC) mice, showing that the hereditary persistence of fetal hemoglobin (HPFH) phenotype was maintained in these cells or was reactivated by an artificial zinc finger-gamma-globin transcription factor and the previously identified fetal globin transactivators fetal Krüppel-like factor (FKLF) and fetal globin-increasing factor (FGIF). These cells may be useful for identifying transcription factors that reactivate gamma-globin synthesis or screening gamma-globin inducers for the treatment of sickle cell disease or beta-thalassemia. PMID:16131492

331

Can we separate the anthropogenic component from the natural component of radon in the vicinity of a uranium mill tailings storage site?  

The European directive 96/29/EURATOM (adapted to the French law, decree 2002-460) limits to 1 milli-sievert the annual exposure of the public due to the radioactivity induced by industrial activities (so called anthropogenic). A method to distinguish natural from anthropogenic radioactivity has to be developed to check that this limit is not reached. Uranium mill tailings storage sites, that induce exhalation of radon into the atmosphere, are particularly concerned by this European directive. Radon is a natural radioactive gas present everywhere on the earth. Therefore, its measured activity near such a site is the sum of two components: a natural one due to the environment and an anthropogenic one induced by the site. The exposition of the public induced by industrial activities is assessed with this anthropogenic component. In order to separate the anthropogenic component from the natural one, it is necessary to measure, as well as the radon-222 activity, the activity of bismuth-214, one of its short-life decay products. Indeed, modelization of atmospheric dispersion (FLUXRAD model) predicts that 10 km around the site, the bismuth activity induced by the site is generally negligible in comparison to the one due to the environment. The measurement of bismuth activity is used, in association with the atmospheric dispersion model PROGENY, to calculate the natural radon component. The anthropogenic component of radon is deduced from this calculation and the measurement of radon activity. This method and its application to a uranium mill tailings storage French site (Bessines-sur-Gartempe, Haute Vienne) will be presented. Attention will be given to the sensitivity of this method to different parameters, such as source description, area characteristics, and parameterization of physical phenomena. (author)

332

Radioactive beams produced by the ISOL method: development for laser ionization and for surface ionization; Faisceaux exotiques par methode ISOL: developpements pour l'ionisation par laser et l'ionisation de surface  

The works were carried out in the framework of the research program PARRNe (production of radioactive neutron-rich nuclei). This program aims to determine optimal conditions to produce intense beams of neutron-rich isotopes. This thesis treats multiple technical aspects related to the production of separate radioactive isotopes in line (ISOL). It deals mainly with the development of the target-source unit which is the key element for projects such as SPIRAL-2 or EURISOL.The first part presents the various methods using fission as production mode and compares them: fission induced by thermal neutrons, induced by fast neutrons and photofission. The experiment carried out at CERN validated the interest of the photofission as a promising production mode of radioactive ions. That is why the institute of nuclear physics of Orsay decided to build a linear electron accelerator at the Tandem d'Orsay (ALTO).The second part of this thesis deals with the development of uranium targets. The X-rays diffraction and Scanning Electron Microscopy have been used as analysis techniques. They allowed to determine the chemical and structural characteristics of uranium carbide targets as function of various heating temperatures. After the production, the process of ionization has been studied. Two types of ion source have been worked out: the first one is a surface ion source and the second one is a source based on resonant ionization by laser. These two types of sources will be used for the ALTO project. (author)

333

Report of Activity, July 1995 - June 1997; Rapport d`activite Juillet 1995 - Juin 1997  

The LPC (Laboratoire de Physique Corpusculaire) dedicated the major part of its 50 years activity to the Physics of Heavy Ions research conducted at GANIL. The activity in last two years on which this report is focused refers to this domain. Of special priority was the topics of hot and /or compressed nuclear matter aiming at understanding the physics of multifragmentation.The new ionization chambers INDRA and development of control programming required special efforts. A second direction of activity was the study of exotic nuclei particularly of halo nuclei. Specific equipment like the multi-detectors of DEMON and TAPS were designed for approaching the hot nuclei. Projects based on SPIRAL beams and collaborations dedicated to investigation of different new branches of exotic radioactivity ({beta}, xn: TONNERRE project) or mechanisms of induced fusion by radioactive nuclei to produce superheavy nuclei are reported on. The LPC was implied also in two important research programs, PRACEN and GEDEON (treatment of radioactive wastes) which made clear the evolution of research for the next two years: the correct understanding of the mechanisms of light particle production in neutron induced collisions at 20 to 200 MeV. In the frame of NEMO Collaboration that approaches topics related to the weak interactions the Laboratory has developed and tested the trigger system of NEMO3. A program utilizing ion trapping on SPIRAL for efficient studies on {beta}-neutrino angular correlations in superallowed decays will be thus feasible. Contracts like COGEMA and DAMRI oriented toward applied research are also mentioned

334

In vitro covalent binding of 3-(/sup 14/C)methylindole metabolites in goat tissues  

Covalent binding of 3-(/sup 14/C)methylindole (3(/sup 14/C)MI) in crude microsomal preparations of goat lung, liver, and kidney was measured to determine if a reactive intermediate was formed during the in vitro metabolism of 3-methylindole (3MI). The bound radioactivity was highest in lung compared to liver and kidney. The amount of bound radioactivity per nanomole of cytochrome P-450 was approximately 10 times higher in the lung compared to the liver. No detectable bound radioactivity was found when 3-(/sup 3/H)methyloxindole was used as the substrate. Cofactor requirements and the effects of inhibitors indicate that a mixed function oxidase (MFO) system is involved in formation of a reactive intermediate. Inhibitors and conjugating agents that are known to reduce the severity of 3MI-induced lung injury such as piperonyl butoxide (MFO inhibitor) and glutathione (conjugating agent) significantly decreased the in vitro binding of 3(/sup 14/C)MI. The results indicate that a reactive intermediate is produced during the metabolism of 3MI by the MFO system. The organ specificity in binding suggests that covalent binding by lung microsomes may be related to the mechanism of 3MI-induced lung injury.

335

Potential radiological impact of tornadoes on the safety of Nuclear Fuel Services' West Valley Fuel Reprocessing Plant. Volume I. Tornado effects on head-end cell airflow  

This report describes results of a parametric study of the impacts of a tornado-generated depressurization on airflow in the contaminated process cells within the presently inoperative Nuclear Fuel Services fuel reprocessing facility near West Valley, NY. The study involved the following tasks: (1) mathematical modeling of installed ventilation and abnormal exhaust pathways from the cells and prediction of tornado-induced airflows in these pathways; (2) mathematical modeling of individual cell flow characteristics and prediction of in-cell velocities induced by flows from step 1; and (3) evaluation of the results of steps 1 and 2 to determine whether any of the pathways investigated have the potential for releasing quantities of radioactively contaminated air from the main process cells. The study has concluded that in the event of a tornado strike, certain pathways from the cells have the potential to release radioactive materials of the atmosphere. Determination of the quantities of radioactive material released from the cells through pathways identified in step 3 is presented in Part II of this report.

336

Monte-Carlo simulations of neutron-induced activation in a Fast-Neutron and Gamma-Based Cargo Inspection System  

An air cargo inspection system combining two nuclear reaction based techniques, namely Fast-Neutron Resonance Radiography and Dual-Discrete-Energy Gamma Radiography is currently being developed. This system is expected to allow detection of standard and improvised explosives as well as special nuclear materials. An important aspect for the applicability of nuclear techniques in an airport inspection facility is the inventory and lifetimes of radioactive isotopes produced by the neutron radiation inside the cargo, as well as the dose delivered by these isotopes to people in contact with the cargo during and following the interrogation procedure. Using MCNPX and CINDER90 we have calculated the activation levels for several typical inspection scenarios. One example is the activation of various metal samples embedded in a cotton-filled container. To validate the simulation results, a benchmark experiment was performed, in which metal samples were activated by fast-neutrons in a water-filled glass jar. The induced activity was determined by analyzing the gamma spectra. Based on the calculated radioactive inventory in the container, the dose levels due to the induced gamma radiation were calculated at several distances from the container and in relevant time windows after the irradiation, in order to evaluate the radiation exposure of the cargo handling staff, air crew and passengers during flight. The possibility of remanent long-lived radioactive inventory after cargo is delivered to the client is also of concern and was evaluated.

337

Mechanism of pitting corrosion prevention by nitrite in carbon steel exposed to dilute salt solutions. 1998 annual progress report  

'The overall goal of this project is to develop a fundamental understanding of the role of nitrite in preventing the breakdown of protective oxide(s) on carbon steel and the onset of pitting. Pitting corrosion of carbon steel exposed to dilute alkaline salt solutions can be induced by nitrate, sulfate, and chloride ions and is prevented by sufficient concentration of nitrite. A significant example of this material/electrolyte system is the storage and processing of DOE''s high-level radioactive liquid waste in carbon steel tanks. Added nitrite in the waste has a considerable downstream impact on the immobilization of the waste in a stable glass form. Waste tank integrity and glass production efficiency may benefit from the fundamental understanding of nitrite''s role in preventing pitting. This report summarizes progress after approximately six months of effort in this three-year EMSP project. Initial experimental and theoretical work has focused on the electrochemical behavior of carbon steel in simplified non-radioactive solutions that simulate complex dilute radioactive waste solutions. These solutions contain corrosion-inducing species such as nitrate and chloride and the corrosion-inhibiting nitrite at moderately alkaline pHs. The electrochemical behavior of interest here is that of the open-circuit potential of the steel specimen at equilibrium in the experimental electrolyte and the measures of the steel''s passivity and passivity breakdown.'

338

Cellulose Degradation at Alkaline Conditions: Long-Term Experiments at Elevated Temperatures  

The degradation of pure cellulose (Aldrich cellulose) and cotton cellulose at the conditions of an artificial cement pore water (pH 13.3) has been measured at 60{sup o} and 90{sup o}C for reaction times between 1 and 2 years. The purpose of the experiments is to establish a reliable relationship between the reaction rate constant for the alkaline hydrolysis of cellulose (mid-chain scission), which is a slow reaction, and temperature. The reaction products formed in solution are analysed for the presence of the two diastereomers of isosaccharinic acid using high performance anion exchange chromatography combined with pulsed amperometric detection (HPAEC-PAD), other low-molecular weight aliphatic carboxylic acids using high performance ion exclusion chromatography (HPIEC) and for total organic carbon. The remaining cellulose solids are analysed for dry weight and degree of polymerisation. The degree of cellulose degradation as a function of reaction time is calculated based on total organic carbon and on the dry weight of the cellulose remaining. The degradation of cellulose observed as a function of time can be divided in three reaction phases observed in the experiments: (i) an initial fast reaction phase taking a couple of days, (ii) a slow further reaction taking - 100 days and (iii) a complete stopping of cellulose degradation levelling-off at -60 % of cellulose degraded. The experimental findings are unexpected in several respects: (i) The degree of cellulose degradation as a function of reaction time is almost identical for the experiments carried out at 60 {sup o}C and 90 {sup o}C, and (ii) the degree of cellulose degradation as a function of reaction time is almost identical for both pure cellulose and cotton cellulose. It can be concluded that the reaction behaviour of the materials tested cannot be explained within the classical frame of a combination of the fast endwise clipping of monomeric glucose units (peeling-off process) and the slow alkaline hydrolysis at the temperatures tested here. It may be hypothesised that the alkaline hydrolysis has even not been observed in the experiments. However, if this is true, cellulose degradation proceeded via another unknown type of reaction. Mass balances for carbon show that the large majority of reaction products found in solution can be explained by formation of isosaccharinic acids and other low-molecular weight carboxylic acids. With respect to long-term predictions for cellulose degradation at room temperature it can be concluded that the kinetic parameters for alkaline hydrolysis as proposed in the work of PAVASARS (Linkoping Studies in Arts and Science, 196, Linkoping University, Sweden, 1999) are too large and that complete cellulose degradation at these temperatures occurs only within time scales larger than hundreds of years. However, it is not possible from the experimental evidences, to corroborate the validity of a linear extrapolation (Arrhenius equation) of the reaction rates measured at temperatures between 140 and 190{sup o}C to room temperature, from which it was previously concluded that complete cellulose degradation would take time spans of the order of millions of years. An interesting observation in the present experiments is the chemical instability of aisosaccharinic acid at 90{sup o}C, which has been hypothetically interpreted as a fragmentation induced by the sorption of {alpha}-isosaccharinic acid on Ca(OH){sub 2}. Carbon mass balances show that {alpha}-isosaccharinic acid is thereby transformed to other lowmolecular weight carboxylic acids. Such a reaction would be an interesting long-term perspective for performance assessment of the disposal of cellulose-containing radioactive waste, in that it may reduce the concentration of organic compounds strongly complexing radionuclides. (author)

339

A contaminação dos oceanos por radionuclídeos antropogênicos/ The contamination of the oceans by anthropogenic radionuclides  

Abstract in english Several hundreds of artificial radionuclides are produced as the result of human activities, such as the applications of nuclear reactors and particle accelerators, testing of nuclear weapons and nuclear accidents. Many of these radionuclides are short-lived and decay quickly after their production, but some of them are longer-lived and are released into the environment. From the radiological point of view the most important radionuclides are cesium-137, strontium-90 and (more) plutonium-239, due to their chemical and nuclear characteristics. The two first radioisotopes present long half life (30 and 28 years), high fission yields and chemical behaviour similar to potassium and calcium, respectively. No stable element exists for plutonium-239, that presents high radiotoxicity, long half-life (24000 years) and some marine organisms accumulate plutonium at high levels. The radionuclides introduced into marine environment undergo various physical, chemical and biological processes taking place in the sea. These processes may be due to physical dispersion or complicated chemical and biological interactions of the radionuclides with inorganic and organic suspend matter, variety of living organisms, bottom sediments, etc. The behaviour of radionuclides in the sea depends primarily on their chemical properties, but it may also be influenced by properties of interacting matrices and other environmental factors. The major route of radiation exposure of man to artificial radionuclides occuring in the marine environment is through ingestion of radiologically contamined marine organisms. This paper summarizes the main sources of contamination in the marine environment and presents an overview covering the oceanic distribution of anthropogenic radionuclides in the FAO regions. A great number of measurements of artificial radionuclides have been carried out on various marine environmental samples in different oceans over the world, being cesium-137 the most widely measured radionuclide. Radionuclide concentrations vary from region to region, according to the specific sources of contamination. In some regions, such as the Irish Sea, the Baltic Sea and the Black Sea, the concentrations depend on the inputs due to discharges from reprocessing facilities and from Chernobyl accident. In Brazil, the artificial radioactivity is low and corresponds to typical deposition values due to fallout for the Southern Hemisphere.

340

The Italy-Japan Project - Fundamental Research on Cold Transmutation Process for Treatment of Nuclear Wastes  

The IJ Project proposes, as the first phase of research, that confirmation of the cold transmutation using radioactive isotopes such as 137Cs, 90Sr, and 135Cs to non-radioactive elements will be implemented based on the Mitsubishi Heavy Industries, Ltd. (MHI) method. A theoretical background has been given by the TSC-induced nuclear reactions (Proc. ICCF 10). Charge-neutral pseudo-particle of 4d/TSC can become as small as 10 fm radius in its minimum state of squeezing motion, and will make 4D-capture reaction with host metal (or added metal) nuclei in the surface region of permeation (Proc. ICCF 9, 10) samples. Major reaction will be: [ M(A, Z) + 4d/TSCto M(A + 8, Z + 4) + Q . ] Theoretical modeling of the process is briefly explained and resulting reaction products, their decays and final stable isotopes are predicted for 137Cs, 90Sr, and 135Cs transmutation.

 
 
 
 
341

The potential application of silver and positron emission tomography for in vivo dosimetry during radiotherapy  

The possible use of silver as a material for in vivo dosimetry in radiotherapy was investigated. The investigation was carried out using a positron emission tomography (PET) scanner, two clinical accelerators and a phantom with silver implants. The phantom was irradiated several times to doses between 6 and 45 Gy. The resulting activity of positron-emitting isotopes produced in the silver by photonuclear processes was measured. It was found that the two therapeutic beams with energies of 15 MV and 18 MV would produce approximately 8344 and 7013 atoms of the radioactive isotope 106Ag per Gy of absorbed dose per gram of silver. This demonstrates that it is possible to derive absorbed doses from the radioactivity induced in silver by radiation when measured with the PET scanner. Even though the physical basis for this method is found to be sound, its application, for instance to perform quality assurance of stereotactic radiotherapy, needs further study.

342

Simulation of remanent dose rates and benchmark measurements at the CERN-EU high energy reference field facility  

A new approach is presented for the calculation of remanent dose rates from induced radioactivity with the FLUKA Monte-Carlo code. It is based on an explicit calculation of isotope production followed by the transport of photons, positrons, and electrons from the radioactive decay to the point of interest. The approach is benchmarked with a measurement in which samples of different materials were irradiated by the stray radiation field produced by interactions of high-energy hadrons in a copper target. Remanent dose rates were measured at different cooling times with a NaI scintillator-based survey instrument. The results of the simulations are generally in good agreement with the measurements. The method is applied to the prediction of remanent dose rates around the beam cleaning insertions of the LHC. 10 Refs.

343

Low activation materials for fusion  

The viability of fusion as a future energy source may eventually be determined by safety and environmental factors. Control of the induced radioactivity characteristics of the materials used in the first wall and blanket could have a major favorable impact on these issues. In the United States, materials program efforts are focused on developing new structural alloys with radioactive decay characteristics which would greatly simplify long-term waste disposal of reactor components. A range of alloy systems is being explored in order to maintain the maximum number of design options. Significant progress has been made, and it now appears probable that reduced-activation engineering alloys with properties at least equivalent to conventional alloys can be successfully developed and commercialized.

344

The EURISOL Multi Megawatt Target Station, a liquid metal target for a High Power spallation source.  

The European Isotope Separation On-Line Radioactive Ion Beam Facility (EURISOL) is set to be the ‘next-generation’ European Isotope Separation On-Line (ISOL) Radioactive Ion Beam (RIB) facility. It will extend and amplify current research in nuclear physics, nuclear astrophysics and fundamental interactions beyond the year 2013.In EURISOL, four target stations are foreseen, three direct targets of approximately 100 kW of beam power and one multi-MW liquid metal proton-to-neutron converter, all driven by a high-power particle accelerator. In the aforementioned multi-MW target assembly, high-intensity RIBs of neutron-rich isotopes will be obtained by inducing fission in several actinide targets surrounding a liquid metal spallation neutron source.This presentation summarises the work carried out for the Multi Megawatt target station of the EURISOL Design Study with particular attention to the coupled neutronic of the liquid converter and the overall performance of the facility, which will sustain fast neutr...

345

EURISOL Multimegawatt Target Unit - MAFF Configuration: Dosimetry and Activation Studies  

The EURopean Isotope Separation On-Line Radioactive Ion Beam (EURISOL) project aims at building a facility to produce radioactive ion beams with intensities two to three orders of magnitude higher than those presently available. A 4-MW (1-GeV, 4-mA) proton beam hits a liquid mercury converter, generating, by spallation reactions, high neutron fluxes that induce fission in surrounding fissile targets. In this work, Monte Carlo calculations of dose rate and activation were carried out to identify the necessary shielding and access restrictions for each section of the facility, including maintenance, storage, and remote control spaces. These calculations allowed an optimization of the materials chosen for the assembly, based on the radioprotection issues, while taking into account the desired performance of the system. The results of the design studies indicate that the intended performance parameters (namely neutron fluxes, fission rates, and easy fission target manipulation) of the EURISOL multimegawatt target...

346

Modelling coupled chemico-osmotic and advective-diffusive transport of nitrate salts in the Callovo-Oxfordian Clay  

Chemico-osmosis is a recognized phenomenon taking place in clay mineral-rich sedimentary formations and a number of questions have been raised concerning its potential effects on pressure fields in and around underground radioactive waste repositories installed in such formations. Certain radioactive waste packages contain large quantities of nitrate salts whose release might result in the presence of highly concentrated salt solutions in the disposal cells, during their resaturation after closure of the facility. This would lead to large solute concentration gradients within the formation's porewater which could then potentially induce significant chemico-osmotic fluxes. In this paper, we assess the impact of chemico-osmotic fluxes on the water pressure during the post-closure period of a...

347

Recent progress in safety assessments of Japanese water-cooled solid breeder test blanket module  

This paper presents summary of preliminary safety assessment of the water-cooled solid breeder (WCSB) test blanket module (TBM) proposed by Japan for the ITER TBM test program. For the purpose of basic evaluation of source terms on nuclear heating and radioactivity generation, distribution of neutron flux, tritium breeding ratio, nuclear heating, decay heat and induced activity of radioactive waste are calculated. For the purpose of occupational radiological exposure evaluation, radiological isotope (RI) inventories, i.e., tritium in the breeder pebble bed, tritium in purge gas, permeated tritium in cooling system and active corrosion product (ACP) in the cooling system, are estimated. Failure mode effect analysis (FMEA) has been carried out for identification of the postulated initiating ...

348

Avalanche counter and encoder system for counting and mapping radioactive specimens  

An apparatus is described for detecting radioactive sources on a test specimen, the apparatus comprising: a counter having a gas filled chamber, the chamber being formed by an electrically conductive planar window and a parallel semiconductive surface spaced from the window, and adapted for having an electric field imposed within the chamber by a voltage differential between the window and the semiconductive surface; an encoder surface spaced form the semiconductive surface and having geometrically arrayed elements thereon for receiving an electrical charge induced on the elements by an ion avalanche occurring within the chamber in response to entry of a radioactive particle into the chamber; and a dielectric layer between the semiconductive surface and the encoder surface, the semiconductive surface forming a coating on one side of the layer and the arrayed elements forming a coating on the opposite side of the layer.

349

Excitation Functions of Product Nuclei from 40-2600 MeV Proton-Irradiated 206,207,208,natPb and 209Bi  

The work is aimed at experimental determination of the independent and cumulative yields of radioactive residual nuclei produced in intermediate-energy proton-irradiated thin targets made of highly isotopic enriched and natural lead (206,207,208,natPb) and 209Bi. 5972 radioactive product nuclide yields have been measured in 55 thin targets induced by 0.04, 0.07, 0.10, 0.15, 0.25, 0.6, 0.8, 1.2, 1.4, 1.6, and 2.6 GeV protons extracted from the ITEP U-10 proton synchrotron. The measured data have been compared with data obtained at other laboratories as well as with theoretical simulations by seven codes. We found that the predictive power of the tested codes is different but is satisfactory for most of the nuclides in the spallation region, though none of the codes agree well with the data in the whole mass region of product nuclides and all should be improved further.

350

Long-term experimental evidences of saturation of compacted bentonite under repository conditions  

This paper summarises the information gathered in the last 15years on the saturation of compacted bentonite obtained from different laboratory-scale tests, a large-scale mock-up test, and a real-scale in situ test, that were performed to simulate the conditions of the bentonite barrier in a high-level radioactive waste repository and to better understand the hydration/heating processes. In all the tests the bentonite used was the Spanish FEBEX bentonite, the maximum temperature in the system was 100^oC and the water used was of the granitic type, with low salinity. Some of the tests were running for more than thirteen years. The migration of water vapour in areas affected by the high temperature induced by the radioactive waste decay is very rapid, its extent depending on the actual temper...

351

Radiochemical aspects of liquid mercury spallation targets  

Liquid metal spallation targets using mercury as target material are used in state-of-the-art high power pulsed neutron sources that have been constructed in the USA and Japan within the last decade. Similar target concepts were also proposed for next generation ISOL, b-beam and neutrino facilities. A large amount of radioactivity will be induced in the liquid metal during operation caused by the interaction of the target material with the intense proton beam. This radioactivity - carried by a wide range of radioisotopes of all the elements of the periodic table from hydrogen up to thallium - must be considered for the assessment of safe operation and maintenance procedures as well as for a final disposal of the used target material and components. This report presents an overview on chemi...

352

Traceable measurements of the activity concentration in air  

The nuclear reactions induced by high energetic protons in heavy targets such as UC/sub 2/ and ThC cause a particular, complex radiation protection task at facilities like ISOLDE: the measurement of a mixture of different isotopes of the radioactive noble gas radon and the radon progenies in air. The knowledge of their respective activity concentration is fundamental for exposure assessments. Due to the complex mixture of activity concentrations in air, its precise determination is quite difficult. Therefore, a new procedure for taking reference samples was developed and implemented for the traceable measurement of the activity concentration of radioactive ions (e.g., radon progenies) in air. This technique is combined by measuring alpha -particles with a multi-wire ionization chamber for the parallel on-line determination of the activity concentration of different radon isotopes. (10 refs).

353

Radiological considerations on multi-MW targets. Part II: After-heat and temperature distribution in packed tantalum spheres  

CERN is designing a Superconducting Proton Linac (SPL) to provide a 2.2 GeV, 4 MW proton beam to feed facilities like, for example, a future Neutrino Factory or a Neutrino SuperBeam. One of the most promising target candidates is a stationary consisting of a Ti container filled with small Ta pellets. The power deposited as heat by the radioactive nuclides (the so-called after-heat) can considerably increase the target temperature after ceasing operation, if no active cooling is provided. An estimate of the induced radioactivity and after-heat was performed with the FLUKA Monte Carlo code. To estimate the highest temperature reached inside the target, the effective thermal conductivity of packed spheres was evaluated using the basic cell method. A method for estimating the contribution to heat transmission from radiation is also discussed.

354

Evaluation of the radioactivity of the pre-dominant gamma emitters in components used at high-energy proton accelerator facilities.  

At a high-energy, high-intensity proton accelerator facility, the accelerator components inside the beam-line tunnel and the concrete wall of the tunnel are activated due to beam loss during operation. During maintenance work inside the tunnel, radiation emitted from these activated materials can cause exposure to radiation workers. In this study, the relation between the surface dose rate of activated materials and the induced radioactivity was considered, and an evaluation of the major radioactivity using the surface dose rate was made. It has been revealed that (22)Na in Al samples and (54)Mn in Fe samples, (60)Co and (54)Mn in Fe samples, and (60)Co in Fe and Cu samples are principal residual radionuclides after a few hundred days of cooling about a few years of cooling and approximately 10 y of cooling, respectively. PMID:17164270

355

Effect of microorganisms on the plutonium oxidation states  

Particular microbes from substrates at the low-level radioactive waste repository in the Ignalina NPP territory were exposed to {sup 239}Pu (IV) at low pH under aerobic conditions. Pu(III) and Pu(IV) were separated and quantitatively evaluated using the modified anion exchange method and alpha spectrometry. Tested bacteria Bacillus mycoides and Serratia marcescens were more effective in Pu reduction than Rhodococcus fascians. Fungi Paecillomyces lilacinus and Absidia spinosa var. spinosa as well as bacterium Rhodococcus fascians did not alter the plutonium oxidation state. - Highlights: Black-Right-Pointing-Pointer Particular microbes from low-level radioactive waste repository were exposed to Pu (IV). Black-Right-Pointing-Pointer Some tested bacteria induced slight Pu (IV) reduction at low pH under aerobic conditions. Black-Right-Pointing-Pointer Tested fungi did not show peculiarities to alter Pu oxidation state. Black-Right-Pointing-Pointer The modified radiochemical method was applied to differentiate Pu oxidation states.

356

Effect of morphine on biliary dynamics. A scintigraphic study with /sup 99m/Tc-HIDA  

The effect of morphine on biliary dynamics was studied by cholescintigraphy with /sup 99m/Tc-HIDA. Among 30 normals without morphine injection 3 did not demonstrate intestinal radioactivity after 1 h, whereas all visualized the gallbladder. Eight normals with morphine injection did not demonstrate intestinal radioactivity after 2 h, but all had gallbladder visualization very early. Variables of the time-activity curves from liver areas did not point to impaired uptake or excretion. Morphine-induced increase in resistance to passage from the common duct to the intestines in normals is of a magnitude that forces the total amount of bile to accumulate in the gallbladder. Results from 11 patients after cholecystectomy indicate that the increase in pressure is less than the maximal secretory pressure of the liver. The resorptive capacity and the compliance of the gallbladder enable these events to take place without signs of secondary liver impairment.

357

SODIUM COOLING OF NUCLEAR REACTORS  

In spite of difficulties in its handling, liquid sodium could play sn important role in the future as a reactor coolant. At the present state of technological development, sodium can be considered only for fast reactors, since it does not slow down neutrons. Sodium is also of interest for thermal reactors since it allows a high temperature to be reached without pressure. The technology of sodium and its corrosive effects are described. Heat transfer by sodium and the possibility of calculating heat transfer with Nusselt's potential formulus are discussed. The radioactivity induced in the sodium by neutron beams is important in its utilization, and the radioactivity equilibrium can be calculated. The construction of heat exchangers, pumpe, and instruments for pressure, level, and flow measurements are described. Some data on the operation of the Sodium Reactor Experiment are given. (auth)

358

EURISOL-DS Multi-MWatt Hg Target: Neutron flux and fission rate calculations for the MAFF configuration  

The EURISOL (The EURopean Isotope Separation On-Line Radioactive Ion Beam) project aims at producing high intensity radioactive ion beams produced by neutron induced fission on a fissile target (235U) surrounding a liquid mercury converter. A proton beam of 1 GeV and 4 MW impinges on the Hg converter generating by spallation reactions high neutron fluxes. In this work the state-of-the-art Monte Carlo codes MCNPX and FLUKA were used to assess the neutronics performance of the system which geometry, inspired from the MAFF concept, allows a versatile manipulation of the fission targets. The objective of the study was to optimize the geometry of the system and the materials used in the fuel and reflector elements of the system, in order to achieve the highest possible fission rate.

359

Well Logging. Data Acquisitions and Applications  

This book provides information on the following topics in the petroleum domain: Review of Fundamental Notions, General Processes used for Recording Physical Parameters, Generalities on Electrical Measurements, Resistivity Measurements, Conductivity Measurements, Electromagnetic Wave Propagation and Attenuation Measurements, Magnetic Susceptibility and Total Magnetic Field Measurements, Spontaneous Potential Measurement, Generalities on Nuclear Measurements, Generalities on Natural Radioactivity, Total Natural Radioactivity Measurements, Spectrometry of Natural Activity, Density and Photoelectric Index Measurements, Generalities on Neutron Physics, Neutron Porosity Measurements, Spectrometry of Induced Gamma Rays, Thermal Neutron Die-Away Measurements, Nuclear Magnetic Resonance Measurements, Generalities on Acoustic Measurements, Sonic Transit Time Measurements, Sonic Amplitude and Attenuation Measurements, Well Seismic Techniques, Generalities on Rock Texture and Structure Determination, Dip and Image Acquisition, Interpretation and Applications, Temperature Measurements, Borehole Caliper Measurements, Wire line Rock Sampling, Fluid Sampling and Pressure Measurements, Place and Role of Logging in Petroleum Exploration, Logging Programs and''Quick-look'' Methods. (author)

360

Fast neutron therapy at Edinburgh: staff protection  

The major hazards encountered by staff using neutrons for radiotherapy are discussed. Specific reference is made to the experience gained at the MRC Cyclotron Unit at the Western General Hospital, Edinburgh, using neutrons generated by the d(15 MeV) + Be reaction. The neutron therapy facility consists of a cyclotron and both a fixed horizontal and an isocentric therapy beam, and staff protection during five years' operation is reviewed. Levels of induced activity in the cyclotron and therapy equipment are reported and problems of radioactive contamination discussed. Summaries of whole-body and finger dose equivalents received by engineering staff, and of whole-body dose equivalents received by physics and radiography staff, are presented and analysed. It is shown that, although doses received by staff are higher than for staff in an X-ray facility, they are all well below the maximum permissible levels, and it is also concluded that radioactive contamination of staff is minimal.

 
 
 
 
361

Production of high-intensity RIB at SPES  

The SPES Project at INFN Laboratori Nazionali di Legnaro SPES Technichal Design Report - (www.lnl.infn.it/approxspes/TDR2008/) is now in its early construction phase. SPES is an ISOL type Radioactive Ion Beam (RIB) J.Khalili, E. Roeckl, The Euroschool Lect. on Phys. with Exotic Beams, Vol. II, Springer (2006) facility for the production of neutron-rich radioactive nuclei by uranium fission. RIBs will be produced by proton induced fission on a UCx multi foil direct target at a rate of 10{sup 13} fps, more than one order of magnitude larger than the currently available beam intensities. The recent developments on the production, ionization and acceleration of RIBs at SPES are hereafter presented.

362

Beam dynamics design studies of a superconducting radioactive ion beam postaccelerator  

The HIE-ISOLDE project at CERN proposes a superconducting upgrade to increase the energy range and quality of the radioactive ion beams produced at ISOLDE, which are currently postaccelerated by the normal conducting radioactive ion beam experiment linac. The specification and design choices for the HIE-ISOLDE linac are outlined along with a comprehensive beam dynamics study undertaken to understand and mitigate the sources of beam emittance dilution. The dominant cause of transverse emittance growth was attributed to the coupling between the transverse and longitudinal motions through the phase dependence of the rf defocusing force in the accelerating cavities. A parametric resonance induced by the coupling was observed and its excitation surveyed as a function of transverse phase advance using numerical simulations and analytic models to understand and avoid the regions of transverse beam instability. Other sources of emittance growth were studied and where necessary ameliorated, including the beam steering...

363

Radioactive ions for solid-state investigations at magnetic surfaces and interfaces  

Hyperfine interactions observed at isomeric states of radioactive probe nuclei are used as a tool for solid-state investigations. This method is sensitive to atomic-scale properties. In recent years surface and interface investigations using radioactive probes delivered many results which can hardly be achieved by any other method. Several groups, e.g., from Konstanz, Leuven, Groningen, Aarhus, Uppsala, Tel Aviv, Pennsylvania, contributed to this field. Our group studies magnetic properties at surfaces and interfaces performing perturbed angular correlation (PAC) measurements in the UHV chamber ASPIC (Apparatus for Surface Physics and Interfaces at CERN). We take advantage of the enhanced variety of PAC probes delivered by the on-line mass separator ISOLDE. First, we report on measurements of magnetic hyperfine fields (B/sub hf/) at Se adatoms on a ferromagnetic substrate using /sup 77/Se as a PAC probe. The investigation of induced magnetic interactions in nonmagnetic materials is a further subject of our st...

364

PIXE analysis of U and Pu from hot particles: K-lines vs L-lines  

Transuranic nuclides have been released into the environment since the beginning of the nuclear age. In many of the areas so contaminated, a significant fraction of the plutonium appears under the form of radioactive particles (also called `hot' particles). In previous works, Garcia Lopez et al. (2007) [1] and Jimenez-Ramos et al. (2010) [2], radioactive particles from aircraft accidents in Palomares and Thule have been characterized. Using micro-Proton Induced X-ray Emission (m-PIXE) and confocal X-ray fluorescence microprobe (m-XRF), the L-lines of the main components in these particles, U and Pu, were analyzed. In this work, the key goal is the possibility to determine elemental ratios and concentration of transuranic elements in hot particles from the same areas but using their K-lines...

365

Spectroscopic microscopy as a powerful tool for the assessment of dermal exposure to pesticides and environmental pollutants  

FTIR Microscopy and Computerized Video Optical Imaging in Ultraviolet Induced Visible fluorescence Techniques were used to study the behavior of malathion and deltamethrin through die skin layers of rats exposed to dermal doses of the individual insecticide. The technique was also shown to be useful for monitoring penetration of pesticide through protective clothing and therefore may serve as a straight forward direct tool for assessing human dermal exposure to pesticides. One advantage of this techniques is the ability to detect both parent compounds and their metabolites by scanning for the desired wave numbers in the IR spectra or by controlling excitation and emission wavelengths. The technique was also compared to microscopic autoradiography where the skin was treated with radioactive malathion and distribution of the radioactivity was located by gel X Ray film on the microscope slide.

366

Effect of gamma-irradiation on adsorption properties of Slovak bentonites  

One of the basic prerequisites for the use of bentonite as engineering barrier in deep geological repositories for radioactive waste and spent nuclear fuel is their stability against ionizing radiation stemming from radionuclides present in radioactive waste and spent nuclear fuel. The aim of this study was to compare the changes in the adsorption properties of selected Slovak bentonites in relation to uranium fission products (137Cs and 90Sr), prior to and after irradiation of bentonites with a 60Co ?-source and specifying the changes in the structure of Slovak bentonites induced by ?-radiation. The changes in irradiated natural forms of Slovak bentonites and the changes in their natrified analogues and fractions with different grain sizes were studied from five Slovak deposits: Jelšov...

367

Calculation of Residual Dose Rates and Intervention Scenarios for the LHC Beam Cleaning Insertions-Constraints and Optimization  

Radiation protection of the personnel who will perform interventions in the LHC Beam Cleaning Insertions is mandatory and includes the design of equipment and the establishment of work procedures. Residual dose rates due to activated equipment are expected to reach significant values such that any maintenance has to be planned and optimized in advance. Three-dimensional maps of dose equivalent rates at different cooling times after operation of the LHC have been calculated with FLUKA. The simulations are based on an explicit calculation of induced radioactivity and of the transport of the radiation from the radioactive decay. The paper summarizes the results for the Beam Cleaning Insertions and discusses the estimation of individual and collective doses received by personnel during critical interventions, such as the exchange of a collimator or the installation of Phase 2. The given examples outline the potential and the need to optimize, in an iterative way, the design of components as well as the layout of ...

368

ENGINEERING DESIGN OF THE EURISOL MULTI-MW SPALLATION TARGET  

The European Isotope Separation On-Line Radioactive Ion Beam project (EURISOL) is set to design the ‘next-generation’ European Isotope Separation On-Line (ISOL) Radioactive Ion Beam (RIB) facility. It will extend and amplify current research on nuclear physics, nuclear astrophysics and fundamental interactions beyond the year 2010. In EURISOL, four target stations are foreseen, three direct targets of approximately 100 kW of beam power and one multi-MW target assembly, all driven by a high-power particle accelerator. In this high power target station, high-intensity RIBs of neutron-rich isotopes will be obtained by inducing fission in several actinide targets surrounding a liquid metal spallation neutron source. This article summarises the work carried out within Task 2 of the EURISOL Design Study, with special attention to the coupled neutronics of the mercury proton-to-neutron converter and the fission targets. The overall performance of the facility, which will sustain fast neutron fluxes of the order ...

369

The multi megawatt target station integration of the MAFF/PIAFE fission target design  

The European Isotope Separation On-Line Radioactive Ion Beam Facility (EURISOL) is set to be the ‘next-generation’ European Isotope Separation On-Line (ISOL) Radioactive Ion Beam (RIB) facility. It will extend and amplify current research on nuclear physics, nuclear astrophysics and fundamental interactions beyond the year 2010.In EURISOL, four target stations are foreseen, three direct targets of approximately 100 kW of beam power and one multi-MW liquid metal proton-to-neutron converter, all driven by a high-power particle accelerator. In the aforementioned multi-MW target assembly, high-intensity RIBs of neutron-rich isotopes will be obtained by inducing fission in several actinide targets surrounding a liquid metal spallation neutron source.This article summarises the work carried out within Task 2 of the EURISOL Design Study, with special attention to the coupled neutronics of the liquid converter and fission target (MAFF/PIAFE design like) and the overall performance of the facility, which will sust...

370

Experimental study of mechanical behaviour of a clay-stone: application to nuclear waste disposals; Etude experimentale du comportement mecanique d'argiles raides: application au stockage de dechets radio-actifs  

A study of mechanical behaviour of deep argillaceous rocks from East of France, the 'argilites de l'Est' as a potential host rock for radioactive waste disposal studied by ANDRA, (french national radioactive waste management agency) is presented. Some uniaxial and triaxial compression tests with unloading-reloading cycles were realised on samples from three different depths. Important plastic strains associated to directional degradation of elastic properties show that the two principles strain mechanisms are plasticity and induced anisotropic damage. At microscopic scale, it is related to sliding of clay sheets and oriented microcracks. The influence of mineralogy is that brittle behaviour is more important with calcite while it decreases with clay. (authors)

371

Artificial Sweeteners: Any Effect on Blood Sugar?  

... Book Question Artificial sweeteners: Any effect on blood sugar? Can I use artificial sweeteners if I have ... potassium (Sunett) Sucralose (Splenda) Artificial sweeteners, also called sugar substitutes, offer the sweetness of sugar without the ...

372

Total Artificial Heart  

... NHLBI on Twitter. What Is a Total Artificial Heart? A total artificial heart (TAH) is a device ... the chest to an outside power source. Normal Heart and CardioWest Total Artificial Heart Figure A shows ...

373

Taking the redpill: Artificial Evolution in native x86 systems  

In analogon to successful artificial evolution simulations as Tierra or avida, this text presents a way to perform artificial evolution in a native x86 system. The implementation of the artificial chemistry and first results of statistical experiments are presented.

374

Chemical toxicity of thorium in Saccharomyces cerevisiae  

Thorium(232Th), an actinoide element, is among the most common naturally-occurring radioactive materials found in the environment. Thorium was used as a radiographic contrast agent(thorotrast) from 1930 to 1955, and many studies on its effects on the human body have been reported. Once thorium is absorbed, the risk of cancer increases due to direct bombardment from alpha-particles with high linear energy transfer during thorium decay. Most of these reports focused on irradiation damage caused by long-term thorium exposure. In contrast, acute thorium toxicity derives more from thorium's chemical reactivity than its radioactive decay. Here, we report the chemical toxicity of thorium using yeast DNA microarray analysis. Thorium treatment of yeast was found to induce 136 genes. Genes involved in “C-compound and carbohydrate metabolism“,“energy”,“cell rescue, defense and virulence” and “biogenesis of cellular component” were induced significantly by thorium treatment. These genes were further classified into the following processes: oxidative stress(7 genes), glycogen and trehalose metabolism (6 genes), and cell wall damage(10 genes). However, only one gene related to DNA damage was induced. These results indicate that thorium causes cell wall damage and induces oxidative stress, and suggest that in order to overcome oxidative stress, cells promote metabolism of energy reserves in the form of glycogen and trehalose.   

375

Técnica de separação da membrana de Descemet para transplante de células endoteliais da córnea: estudo experimental em coelhos/ Technique for separating Descemet membrane for corneal endothelial cells transplantation: experimental study in rabbits  

Abstract in portuguese OBJETIVO: Avaliar a porcentagem de dano endotelial induzido por uma técnica cirúrgica para a separação da membrana de Descemet contendo endotélio sadio, analisar a viabilidade e eficácia desta técnica, e avaliar a porcentagem de dano endotelial causado pela inversão da córnea em câmara anterior artificial. MÉTODOS: As córneas de três grupos de 12 coelhos da linhagem Nova Zelândia foram avaliadas. O grupo 1 foi usado como controle; portanto, as córneas foram (more) analisadas após coletadas e trepanadas. O grupo 2 foi analisado após a inversão da córnea (endotélio para cima na posição convexa), montada em câmara anterior artificial, para o cálculo da porcentagem do dano endotelial induzido por esta inversão. O grupo 3 foi avaliado após a separação entre a membrana de Descemet e o estroma com o uso de substância viscoelástica em córneas invertidas e montadas em câmara anterior artificial. O dano endotelial foi avaliado por meio de fotografias digitais tiradas no microscópio após impregnar o endotélio com vermelho de alizarina. Amostras do grupo 3 foram processadas para avaliação histopatológica. RESULTADOS: O grupo 3 (separação viscoelástica) apresentou um índice de lesão celular endotelial de 10,06%, o grupo 2 apresentou um índice de 3,58% e o grupo controle um índice de 0,18% de lesão celular endotelial (p Abstract in english PURPOSE: To evaluate the percentage of endothelial cell damage induced during a surgical technique of Descemet's membrane separation containing healthy endothelium, analyze the viability and efficacy of this technique, and evaluate the percentage of endothelial cell damage caused by inversion of the cornea on an artificial anterior chamber. METHODS: The corneas from three groups of 12 New Zealand rabbits were evaluated. The Group one was used as the control, so the cornea (more) s were analyzed after collected and trephinated. The Group two was analyzed after inversion of the cornea (endothelial side up at a convex shape) mounted on an artificial anterior chamber to calculate the percentage of endothelial cell damage caused by this inversion. The Group three was evaluated after the separation between the Descemet's membrane and the stroma using viscoelastic substance in corneas inverted and mounted on an artificial anterior chamber. The endothelial cell damage was analyzed by digital photographs taken under a microscope after staining the endothelium with alizarin red. Group three samples were processed for histologic evaluation. RESULTS: The Group three (viscoelastic separation) showed an index of endothelial cell damage of 10.06%, the Group two showed an index of 3.58% and the control group an index of 0.18% of endothelial cell damage (p

376

Energetics of jellyfish locomotion determined from field measurements using a Self- Contained Underwater Velocimetry Apparatus (SCUVA)  

We conduct laboratory measurements of the flow fields induced by Aurelia labiata over a range of sizes using the method of digital particle image velocimetry (DPIV). The flow field measurements are used to directly quantify the kinetic energy induced by the swimming motions of individual medusae. This method provides details regarding the temporal evolution of the energetics during a swimming cycle and its scaling with bell diameter. These types of measurements also allow for the determination of propulsive efficiency, which can be used to compare various methods of propulsion, both biological and artificial. We then describe the development and application of a Self-Contained Underwater Velocimetry Apparatus (SCUVA), a device that enables a single SCUBA diver to make DPIV measurements of animal-fluid interactions in the field. Improvements and adjustments made to the original system will be presented, and a comparison between the animal-induced flow fields in the laboratory and in the field will be made.

377

Subjective visual acuity with simulated defocus  

Abstract Background:- Artificial degradation of vision by inducing dioptric blur is frequently used for evaluating diagnostic equipment. However, the use of lenses is prone to errors as it is adversely affected by eyelid squinting, pupil size, and imprecise lens position. The alternative is a degradation of the stimuli themselves based on a Fourier-optical mathematical model. With this, however, perceptual effects such as -simultaneous blur- induced by the surround may affect acuity. We tested whether both methods, lens induced defocus and mathematical stimulus degradation, yield concordant results. Methods:- We compared both methods in normal subjects, measuring Landolt C acuity at five different levels of defocus from 0 to 8 dioptres. The pupil size was determined individually, chromatic...

378

Laser-induced fluorescence of space-exposed polyurethane  

The object of this work was to utilize laser-induced fluorescence technique to characterize several samples of space-exposed polyurethane. These samples were flown on the Long Duration Exposure Facility (LDEF), which was in a shuttle-like orbit for nearly 6 years. Because of our present work to develop laser-induced-fluorescence inspection techniques for polymers, space-exposed samples and controls were lent to us for evaluation. These samples had been attached to the outer surface of LDEF; therefore, they were subjected to thermal cycling, solar ultraviolet radiation, vacuum, and atomic oxygen. It is well documented that atomic oxygen and ultraviolet exposure have detrimental effects on many polymers. This was a unique opportunity to make measurements on material that had been naturally degraded by an unusual environment. During our past work, data have come from artificially degraded samples and generally have demonstrated a correlation between laser-induced fluorescence and tensile strength or elasticity.

379

Laser-based instrumentation for the detection of chemical agents  

Several laser-based techniques are being evaluated for the remote, point, and surface detection of chemical agents. Among the methods under investigation are optoacoustic spectroscopy, laser-induced breakdown spectroscopy (LIBS), and synchronous detection of laser-induced fluorescence (SDLIF). Optoacoustic detection has already been shown to be capable of extremely sensitive point detection. Its application to remote sensing of chemical agents is currently being evaluated. Atomic emission from the region of a laser-generated plasma has been used to identify the characteristic elements contained in nerve (P and F) and blister (S and Cl) agents. Employing this LIBS approach, detection of chemical agent simulants dispersed in air and adsorbed on a variety of surfaces has been achieved. Synchronous detection of laser-induced fluorescence provides an attractive alternative to conventional LIF, in that an artificial narrowing of the fluorescence emission is obtained. The application of this technique to chemical agent simulants has been successfully demonstrated. 19 figures.

380

pH-dependent inhibition of native GABAA receptors by HEPES  

BACKGROUND AND PURPOSE Artificial buffers such as HEPES are extensively used to control extracellular pH (pHe) to investigate the effect of H+ ions on GABAA receptor function. EXPERIMENTAL APPROACH In neurones cultured from spinal cord dorsal horn (DH), dorsal root ganglia (DRG) and cerebellar granule cells (GC) of neonatal rats, we studied the effect of pHe on currents induced by GABAA receptor agonists, controlling pHe with HCO3- or different concentrations of HEPES. KEY RESULTS Changing HEPES concentration from 1 to 20-mM at constant pHe strongly inhibited the currents induced by submaximal GABA applications, but not those induced by glycine or glutamate, on DH, DRG or GC neurones, increasing twofold the EC50 for GABA in DH neurones and GC. Submaximal GABAA receptor-mediated currents we...

 
 
 
 
381

Droplet Microfluidics for Artificial Lipid Bilayers  

Droplet interface bilayer is a versatile approach that allows formation of artificial lipid bilayer membrane at the interface of two lipid monolayer coated aqueous droplets in a lipid filled oil medium. Versatility exists in the form of voltage control of DIB area, ability of forming networks of DIBs, volume control of droplets and lipid-oil, and ease of reformation. Significant effect of voltage on the area and capacitance of DIB as well as DIB networks are characterized using simultaneous optical and electrical recordings. Mechanisms behind voltage-induced effects on DIBs are investigated. Photo induced effect on the DIB membrane porosity is obtained by incorporating UVC-sensitive photo-polymerizable lipids in DIB. Photo-induced effects can be extended for in-vitro studies of triggered release of encapsulated contents across membranes. A droplet based low voltage digital microfluidic platform is developed to automate DIB formation, which could potentially be used for forming arrays of lipid bilayer membranes.

382

New estrus synchronization and artificial insemination protocol for goats based on male exposure, progesterone and cloprostenol during the non-breeding season  

This study assesses the effectiveness of a method designed to induce and synchronize ovulation in goats during the non-breeding season, allowing for systematic timed artificial insemination (AI), without the need for prior estrus detection. This method (IMA.PRO2) induces ovulation through the "male effect" and a single 25mg dose of progesterone given at the time of buck exposure, and early lysis of the induced corpus luteum by the administration of 75mg of cloprostenol 9 days later. The method was tested in three separate experiments. In experiment 1, estrus was detected in 87.5% of the treated goats 37.0+-1.4h after cloprostenol administration, with the preovulatory LH surge occurring 40.5+-1.6h after the cloprostenol injection. In experiment 2, data from 503 does revealed no significant ...

383

Modelling light-driven proton pumps in artificial photosynthetic reaction centers  

We study a model of a light-induced proton pump in artificial reaction centers. The model contains a molecular triad with four electron states (i.e., one donor state, two photosensitive group states, and one acceptor state) as well as a molecular shuttle having one electron and one proton-binding sites. The shuttle diffuses between the sides of the membrane and translocates protons energetically uphill: from the negative side to the positive side of the membrane, harnessing for this purpose the energy of the electron-charge-separation produced by light. Using methods of quantum transport theory we calculate the range of light intensity and transmembrane potentials that maximize both the light-induced proton current and the energy transduction efficiency. We also study the effect of temperature on proton pumping. The major conclusions of our work agree well with experimental results. The light-induced proton pump in our model gives an efficiency (to convert photon energy into a proton motive force) of about 10...

384

Liquefaction at Oceano, California, during the 2003 San Simeon earthquake  

The 2003 M 6.5 San Simeon, California, earthquake caused liquefaction-induced lateral spreading at Oceano at an unexpectedly large distance from the seismogenic rupture. We conclude that the liquefaction was caused by ground motion that was enhanced by both rupture directivity in the mainshock and local site amplification by unconsolidated fine-grained deposits. Liquefaction occurred in sandy artificial fill and undisturbed eolian sand and fluvial deposits. The largest and most damaging lateral spread was caused by liquefaction of artificial fill; the head of this lateral spread coincided with the boundary between the artificial fill and undisturbed eolian sand deposits. Values of the liquefaction potential index, in general, were greater than 5 at liquefaction sites, the threshold value that has been proposed for liquefaction hazard mapping. Although the mainshock ground motion at Oceano was not recorded, peak ground acceleration was estimated to range from 0.25 and 0.28g on the basis of the liquefaction potential index and aftershock recordings. The estimates fall within the range of peak ground acceleration values associated with the modified Mercalli intensity = VII reported at the U.S. Geological Survey (USGS) \\

385

Infant feeding and obesity risk in the child.  

Early nutrition in infancy may influence later child health outcomes including overweight through 'programming'. Systematic reviews suggest that breastfeeding is associated with a modest reduction in the risk of later overweight and obesity. This commentary explores some of these mechanisms behind this association. Generally breastfed infants are leaner than artificially (formula)-fed infants and behavioural and hormonal mechanisms may explain this difference. The theory is that a high nutrient diet in infancy adversely programs the principal components of the metabolic syndrome in the child (body mass index, blood pressure and blood lipids) by promoting growth acceleration, whereas slower growth benefits later cardiovascular disease and its risk factors. Artificial-feeding stimulates a higher postnatal growth velocity with the adiposity rebound occurring earlier in those children who have greater fatness later, whereas breastfeeding has been shown to promote slower growth. The adverse long-term effects of early growth acceleration emerge as fundamental in later overweight and obesity. The higher protein content of artificial baby milk compared to the lower protein content in breastmilk is responsible for the increased growth rate and adiposity during the influential period of infancy of formula-fed infants. Breastfeeding, on the other hand, has a protective effect on child overweight and obesity by inducing lower plasma insulin levels, thereby decreasing fat storage and preventing excessive early adipocyte development. Plausible biological mechanisms underlying the protective effect of breastfeeding against obesity are based on the unique composition of human milk and the metabolic and physiological responses to human milk. PMID:22946146

386

Medical Imaging of Mummies and Bog Bodies  

Mummies are human remains with preservation of nonbony tissue. Mummification by natural influences results in so-called natural mummies, while mummification induced by active (human) intervention results in so-called artificial mummies, although many cultures practiced burial rites which to some degree involved both natural and artificial mummification. Since they are so uniquely well-preserved, mummies may give many insights into mortuary practices and burial rites. Specifically, the presence of soft tissues may expand the scope of paleopathological studies. Many recent mummy studies have focused on the development and application of non-destructive methods for examining mummies, especially radiography and CT scanning with advanced 3D visualizations. Indeed, the development of commercially available CT scanners in the 1970s meant that for the first time the 3D internal structure of mummies and bog bodies could be studied non-destructively. This article describes the history of mummy radiography and CT scanning, and some of the problems and opportunities involved in applying these techniques, derived for clinical use, on naturally and artificially preserved ancient human bodies. Unless severely degraded, bone is quite readily visualized, but accurate imaging of preserved soft tissues, and pathological lesions therein, may require considerable post-image capture processing of CT data.

387

An active artificial cornea with the function of inducing new corneal tissue generation in vivo-a new approach to corneal tissue engineering  

An active artificial cornea which can perform the function of inducing new cornea generation in vivo but does not need culture cells in vitro and which has similar optical and mechanical properties to those of the human cornea was constructed. An animal keratoplasty experiment using the artificial cornea as the implant showed that the animals' corneas could keep smooth surface and clear stroma postoperatively, and that the repopulation of the host's keratocytes, the degradation of the implant and new corneal tissue generation were completed at 5-6 months after surgery. Such an artificial cornea has several advantages over other corneal equivalents constructed in the typical way of tissue engineering: in having similar mechanical and optical properties to those of the human cornea and with no exogenetic cells, it can be used universally in different implantation surgeries without immunoreaction; it is easy to prepare and process into different shapes and sizes on a large scale, and suitable for long-distance transportation and long-term storage. All these characteristics make it a new approach to cornea tissue engineering having potential in many clinical applications.

388

Induction of Fetal Hemoglobin In Vivo Mediated by a Synthetic ?-Globin Zinc Finger Activator.  

Sickle cell disease (SCD) and ?-thalassemia patients are phenotypically normal if they carry compensatory hereditary persistence of fetal hemoglobin (HPFH) mutations that result in increased levels of fetal hemoglobin (HbF, ?-globin chains) in adulthood. Thus, research has focused on manipulating the reactivation of ?-globin gene expression during adult definitive erythropoiesis as the most promising therapy to treat these hemoglobinopathies. Artificial transcription factors (ATFs) are synthetic proteins designed to bind at a specific DNA sequence and modulate gene expression. The artificial zinc finger gg1-VP64 was designed to target the -117 region of the (A)?-globin gene proximal promoter and activate expression of this gene. Previous studies demonstrated that HbF levels were increased in murine chemical inducer of dimerization (CID)-dependent bone marrow cells carrying a human ?-globin locus yeast artificial chromosome (?-YAC) transgene and in CD34(+) erythroid progenitor cells from normal donors and ?-thalassemia patients. Herein, we report that gg1-VP64 increased ?-globin gene expression in vivo, in peripheral blood samples from gg1-VP64 ?-YAC double-transgenic (bigenic) mice. Our results demonstrate that ATFs function in an animal model to increase gene expression. Thus, this class of reagent may be an effective gene therapy for treatment of some inherited diseases. PMID:22778925

389

Space physiology VI: exercise, artificial gravity, and countermeasure development for prolonged space flight.  

When applied individually, exercise countermeasures employed to date do not fully protect the cardiovascular and musculoskeletal systems during prolonged spaceflight. Recent ground-based research suggests that it is necessary to perform exercise countermeasures within some form of artificial gravity to prevent microgravity deconditioning. In this regard, it is important to provide normal foot-ward loading and intravascular hydrostatic-pressure gradients to maintain musculoskeletal and cardiovascular function. Aerobic exercise within a centrifuge restores cardiovascular function, while aerobic exercise within lower body negative pressure restores cardiovascular function and helps protect the musculoskeletal system. Resistive exercise with vibration stimulation may increase the effectiveness of resistive exercise by preserving muscle function, allowing lower intensity exercises, and possibly reducing risk of loss of vision during prolonged spaceflight. Inexpensive methods to induce artificial gravity alone (to counteract head-ward fluid shifts) and exercise during artificial gravity (for example, by short-arm centrifuge or exercise within lower body negative pressure) should be developed further and evaluated as multi-system countermeasures. PMID:23079865

390

Honey stimulates inflammatory cytokine production from monocytes.  

Clinical observations indicate that honey may initiate or accelerate the healing of chronic wounds and has, therefore, been claimed to have anti-inflammatory properties. The aim of this study was to investigate the effects of honey on the activation state of immunocompetent cells, using the monocytic cell line, MonoMac-6 (MM6), as a model. We investigated the effect of each of the three honeys (manuka, pasture and jelly bush) on the release of important inflammatory cytokines from MM6 cells. These honeys, together with a sugar syrup control (artificial honey), were incubated with MM6 cells at a concentration of 1% (w/v) for 0-24h. Cell culture supernatants were tested using specific ELISA assays for tumour necrosis factor-alpha (TNF-alpha) and interleukin (IL)-1beta and IL-6. All honeys significantly increased the TNF-alpha, IL-1beta and IL-6 release from MM6 cells (and human monocytes) when compared with untreated and artificial-honey-treated cells (Phoney significantly induced the maximal release of each cytokine compared with manuka, pasture or artificial honeys (Phoney on wound healing may in part be related to the stimulation of inflammatory cytokines from monocytic cells. Such cell types are known to play an important role in healing and tissue repair. PMID:12824009

391

Maternal milk reduces severity of necrotizing enterocolitis and increases intestinal IL-10 in a neonatal rat model.  

Necrotizing enterocolitis (NEC) is a devastating intestinal disease of premature infants. Maternal milk has been suggested to be partially protective against NEC; however, the mechanisms of this protection are not defined. The aim of this study was to examine the effect(s) of artificial feeding of rat milk (RM)-versus cow milk-based rat milk substitute (RMS) on the development of NEC in a neonatal rat model and elucidate the role of inflammatory cytokines in NEC pathogenesis. Newborn rats were artificially fed with either collected RM or RMS. Experimental NEC was induced by exposure to asphyxia and cold stress and evaluated by histologic scoring of damage in ileum. Intestinal cytokine mRNA expression was determined by real-time PCR. Cytokine histologic localization was performed by confocal microscopy. Similar to human NEC, artificial feeding of RM reduces the incidence and severity of NEC injury in neonatal rats. Freezing and thawing of collected RM did not eliminate the protective effect of maternal milk. Ileal IL-10 expression was significantly increased in the RM group compared with RMS. Increased IL-10 peptide production was detected in the RM group with signal localized predominantly in the cytoplasm of villus epithelial cells. These results suggest that the protective effect of maternal milk is associated with increased production of anti-inflammatory IL-10 in the site of injury. Better understanding of the mechanisms underlying these protective effects could be beneficial either in the prevention of NEC or in the development of future therapeutic strategies to cure NEC. PMID:12595590

392

Wear Resistance of AZ91D Magnesium Alloy with and Without Microarc Oxidation Coating and Ti6Al4V Alloy in Artificial Saliva  

The wear resistances of AZ91D magnesium alloy with and without microarc oxidation (MAO) coating and Ti6Al4V alloy in artificial saliva were investigated at room temperature. The wear resistance of AZ91D magnesium alloy in artificial saliva was significantly improved after microarc oxidation treatment. The volume loss of untreated AZ91D magnesium alloy sample was 20.95 times of that of AZ91D magnesium alloy with MAO coating, and that of Ti6Al4V was 5.42 times of that of MAO. Furthermore, the wear resistance of AZ91D magnesium alloy was lower than that of Ti6Al4V alloy in artificial saliva. The wear mechanisms of AZ91D magnesium and Ti6Al4V were discussed. It was found that the wear mechanism of the MAO was associated with abrasion and microfracture. There were two dominative wear mechanisms for AZ91D alloy and Ti6Al4V alloy under the loading conditions used in the experiment, namely, micro-machining wear and deformation-induced wear.

393

S-adenosylmethionine metabolism and DNA methylation in hydrazine-treated rats  

The treatment of rats with hepatotoxic doses of hydrazine (NH2-NH2) induces the rapid formation of 7-methylguanine and O6-methylguanine in liver DNA. The methyl moiety in these reactions might be derived from the cellular S-adenosylmethionine pool because radioactivity administered to these rats as methionine rapidly appears in the DNA as methylated guanine. An increased incorporation of radioactivity into 5-methylcytosine was previously reported followed by subsequent suppression. This increased radiolabeling of 5-methylcytosine coincided with time of maximal DNA guanine methylation. To determine the nature of S-adenosylmethionine metabolism during the period of DNA methylation induced by hydrazine treatment, and to determine if the increased radiolabeling of 5-methylcytosine at this time reflected an actual increase in 5-methylcytosine synthesis, liver DNA synthesis and S-adenosylmethionine levels and turnover were assayed. Liver S-adenosylmethionine concentrations varied slightly between control rats and hydrazinetreated rats during the first five hours after hydrazine administration, and no difference was detectable in the incorporation of administered (3H)methionine into S-adenosylmethionine. Because S-adenosylmethionine specific radioactivity in hydrazine-treated rats was not different from control rats, the previously observed increased radiolabeling of 5-methylcytosine appeared to represent an actual increase in synthesis. This conclusion was supported by finding that incorporation of radioactive thymidine into DNA was also accelerated immediately following hydrazine administration, again followed by a decrease. 5-Methylcytosine sythesis, therefore, appears to follow DNA synthesis during hydrazine toxicity, and formation of 7-methylguanine and O6-methylguanine in liver DNA of hydrazine-treated rats occurs during a short period of increased DNA sythesis and 5-methylcytosine formation very early in hydrazine toxicity.

394

Induction of reverse development in two marine Hydrozoans.  

Cnidarians are unique organisms in the animal kingdom because of their unequalled potential to undergo reverse development (RD). The life cycle of some species can temporarily shift ordinary, downstream development from zygote to adult into the opposite ontogenetic direction by back-transformation of some life stages. The potential for RD in cnidarians offers the possibility to investigate how integrative signalling networks operate to control directionality of ontogeny (reverse vs. normal development). Striking examples are found in some hydrozoans, where RD of medusa bud or liberated medusa stages leads to rejuvenation of the post-larval polyp stage. Artificial stress may determine ontogeny reversal. We describe here the results of experimental assays on artificial induction of RD by different chemical and physical inducers on two marine hydrozoans, Turritopsis dohrnii and Hydractinia carnea, showing a different potential for RD. A cascade of morphogenetic events occurs during RD by molecular mechanisms and cellular patterns recalling larval metamorphosis. For the first time, we show here that exposure to cesium chloride (CsCl), an inducer of larval metamorphosis, may also induce RD, highlighting similarities and differences between these two master ontogenetic processes in cnidarians. PMID:17183464

395

Simple Visual Assay for Evaluating the Cortex Contractility of Dictyostelium Cells  

This study presents a simple method for evaluating the cortex contractility of Dictyostelium cells. This assay is based on the artificially-induced actomyosin-mediated contraction of the cortex cytoskeleton. Simultaneous application of Triton X-100 and ATP to Dictyostelium cells induced rapid shrinkage of cell mass after cell lysis. This cellular contraction was dependent on ATP in the medium, and mutant cells lacking myosin II did not show significant contraction. Microscopic measurements of artificially-induced contraction such as this require only a small amount of cell suspension and can provide significant information on the contractile properties of the cortex in target cells. As one example analysis, the magnitude and velocity of the contraction in strains that exogenously expressed Tetrahymena actin or a chimeric actin of Dictyostelium and Tetrahymena were measured. The results revealed certain dominant negative effects of these actin variants with respect to the endogenous Dictyostelium actin. This simple method is thus considered to be a useful tool for the rapid assessment of phenotypes in various cytoskeleton-related mutants either in early-stage studies or in genetic manipulations intending to alter the cellular contractility in Dictyostelium.   

396

Artificial islands in northern Lazio (Italy): evaluation of different hydrodynamic scenarios in support of the design  

The present work shows the assessment of the hypothetical influence on the hydrodynamic field induced by the construction of three artificial islands off the northern coast of Lazio (Italy). The proposed settlements will be realized with cutting-edge techniques already used around the world, allowing to explore, develop, test and apply the possibilities of a truly sustainable development of the coast. Following the identification of suitable sites, the design and construction of these insular facilities will procede locating them in such a way as to protect the coasts, adjusting sediment transportation and encouraging the recovery and development of marine ecosystems with high ecological value. The eco-sustainable islands will be created also using (reusing and recycling) residual material from human activities, as already experienced with considerable success in projects realised worldwide. To assess the effects of artificial islands on the coastline dynamics different scenarios were considered with different design choices and weather conditions through the application of two forecasting mathematical models that calculate wind-induced currents (ADCIRC) and the propagation of waves (STWAVE) and that can also assess the variation of littoral drift effects induced by coastline modifications.

397

Hybrid image processing; Proceedings of the Meeting, Orlando, FL, Apr. 1, 2, 1986  

The conference presents papers on optical pattern recognition; optical image processing, artificial intelligence, and synthetic discrimination functions; digital image processing; and hybrid image processing. Attention is given to multiple optical filter design simulation results, acoustooptic image correlators, texture classification using the Hough transform, iteratively designed optical correlation filters for distortion invariant recognition, and an instrument-induced spatial crosstalk deconvolution algorithm. Papers are also presented on infrared power spectral density diurnal variations and clutter rejection scaling laws for focal plane arrays, the use of complementary analog and digital processing in the removal of local background in low contrast images, and the construction of low noise correlation filters.

398

Force-Free Gravitational Redshift: Proposed Gravitational Aharonov-Bohm Experiment  

We propose a feasible laboratory interferometry experiment with matter waves in a gravitational potential caused by a pair of artificial field-generating masses. It will demonstrate that the presence of these masses (and, for moving atoms, time dilation) induces a phase shift, even if it does not cause any classical force. The phase shift is identical to that produced by the gravitational redshift (or time dilation) of clocks ticking at the atom’s Compton frequency. In analogy to the Aharonov-Bohm effect in electromagnetism, the quantum mechanical phase is a function of the gravitational potential and not the classical forces.

399

Beach Changes around Artificial Reef with Crests on Kaike Coast and their Prediction  

Beach changes around an artificial reef with crests on the Kaike coast were investigated through field observations, and compared with the beach changes around the detached breakwaters. Strong shoreward currents were induced due to wave breaking on the reef, resulting in the formation of a tombolo with a scale less than that of the detached breakwater. Also rip currents were generated, and scouring was measured in the opening. These beach changes were predicted using the BG model proposed by Serizawa et al. (2006). Predicted results were in good agreement with the measured.   

400

Meiosis of autotetraploid Osmunda lancea produced by apospory  

Autotetraploid Osmunda lancea (2n=4x=88) was produced artificially by apospory. The meiotic chromosome configulation of the autotetraploid O. lancea showed the maximum 21 quadrivalent chromosomes at prophase I, in most of the spore mother cells. Their metaphase I plates additionally showed univalent, bivalent and multivalent chromosomes. Anaphase I and II plates showed frequently laggards. To make the meiosis regularly, the suppression system of multivalent chromosome formation might be obtained in the process of evolution in autoploid ferns in nature. Aposporous sporophytes could not be induced from the autotetraploid O. lancea anymore.   

 
 
 
 
401

Flower pigment mutations induced by heavy ion beam irradiation in an interspecific hybrid of Torenia  

The use of heavy ion beams is an effective method for inducing mutations in plants. After irradiation with beams of Nitrogen (N) or Neon (Ne), the frequency of flower color mutants increased through the regeneration of stem or leaf without lateral meristem in an interspecific hybrid of Torenia. From anthocyanin assay results, mutants were divided into two groups. One group involved the deletion of the blue gene (DFR). The other group involved the deletion or duplication of a gene related to pigment production. The results show that heavy ion beams are effective in obtaining artificial mutants.   

402

Thermo-induced Vesicular Dynamics of Membranes Containing Cholesterol Derivatives  

Membrane structural organization is an intrinsic property of a cell membrane. Any changes in lipid composition, and/or any stimuli that affect molecular packing induce structural re-organization. It membrane dynamics provide a means by which changes in structure organization can be determined, upon a change in the membrane internal or external environment. Here, we report on the effect of thermo-stress on membranes containing cholesterol liquid crystal (LC) compounds cholesterol benzoate (BENZO) and oxidized cholesterols. We have (1) revealed that lipid vesicles containing this artificial cholesterol derivative (BENZO) is thermo-responsive, and that this thermo-sensitivity is significantly similar to naturally oxy-cholesterols (2) elucidated the mechanism behind the membrane perturbation. ...

403

Nucleation and growth of precipitates in a Ni-based superalloy  

A study of the early stages of precipitation of the {gamma}'-phase in the commercial Ni-base superalloy Inconel X-750 is presented. Precipitation was induced by artificial aging heat treatments at 700 C during different times ranging up to 10{sup 4} min. Positron lifetime spectroscopy experiments, following the microstructural evolution, revealed a very complicated process of nucleation and growth of the second-phase particles, involving solute clustering and solute segregation. ''Frozen frames'' of the evolution process, chosen on the basis of the lifetime results, were studied by coincidence Doppler technique, which sheds information on the electronic and chemical environment around the positron trapping site. (orig.)

404

Superhydrophobic behavior achieved from hydrophilic surfaces  

The superhydrophobic behavior of a surface can be generally attributed to the combination of its chemical composition and microscale texture. The surface can be both hydrophobic and rough, and the roughness enhances its hydrophobicity. For a natural or artificial surface, superhydrophobic behavior is generally induced by a structured hydrophobic surface. This paper proposes an alternative; that is the superhydrophobic behavior can be obtained from a structured hydrophilic surface. The superhydrophobic behavior of a T-shape micropillar surface coated with diamond-like carbon has been achieved, which experimentally proved the proposed hypothesis that superhydrophobicity can be created from a hydrophilic surface through surface microstructure modification.

405

Search-Free Codebook Mapping for Artificial Bandwidth Extension  

A new codebook mapping algorithm for artificial bandwidth extension (ABE) is introduced in this paper. We design a wideband line spectrum pair (LSP) codebook which is coupled with the same index as the LSP codebook of a narrowband speech codec. The received narrowband LSP codebook indices are used to directly induce wideband LSP codewords. Thus, the proposed scheme eliminates codebook search processing to estimate the wideband spectrum envelope. We apply the proposed scheme to bandwidth extension in adaptive multi-rate (AMR) compressed domain. Its performance is assessed via the perceptual evaluation of speech quality (PESQ), informal listening tests, and weighted million operations per second (WMOPS) calculations.   

406

Leak rate measurements and detection systems  

A research program is under way to evaluate and develop improve leak detection systems. The primary focus of the work has been on acoustic emission detection of leaks. Leaks from artificial flaws, laboratory-generated IGSCCs and thermal fatigue cracks, and field-induced intergranular stress corrosion cracks (IGSCCs) from reactor piping have been examined. The effects of pressure, temperature, and leak rate and geometry on the acoustic signature are under study. The use of cross-correlation techniques for leak location and pattern recognition and autocorrelation for source discrimination is also being considered.

407

Force-free gravitational redshift: a gravitostatic Aharonov-Bohm experiment  

We propose a feasible laboratory interferometry experiment with matter waves in a gravitational potential caused by a pair of artificial field-generating masses. It will demonstrate that the presence of these masses (and, for moving atoms, time dilation) induces a phase shift, even if it does not cause any classical force. The phase shift is identical to that produced by the gravitational redshift (or time dilation) of clocks ticking at the atom's Compton frequency. In analogy to the Aharonov-Bohm effect in electromagnetism, the quantum mechanical phase is a function of the gravitational potential and not the classical forces.

408

Significance of light-induced hook exaggeration as reinforced by the concomitant anatomical change of germinating tomato seeds.  

Progression of the apical hook of tomato, Solanum lycopersicum, exaggerated by phytochrome mediation at the early germination stage is followed in detail macroscopically and anatomically, and its proposed significance, i.e. survival by securing the seed coat release in the field, is reinforced by new findings. Furthermore, after self-release or artificial removal of the seed coat and the endosperm, no hook exaggeration occurs any more. Similar light-induced hook exaggeration (LIHE) is also found in carrot, parsley, and Cryptotaenia japonica, which share some seed characteristics with tomato. These findings also support the above-stated significance. PMID:20930568

409

Signal-dependent dynamics of transcription factor translocation controls gene expression  

Information about environmental stimuli is often transmitted using common signaling molecules, but the mechanisms that ensure signaling specificity are not entirely known. Here we show that the identities and intensities of different stresses are transmitted by modulation of the amplitude, duration or frequency of nuclear translocation of the Saccharomyces cerevisiae general stress response transcription factor Msn2. Through artificial control of the dynamics of Msn2 translocation, we reveal how distinct dynamical schemes differentially affect reporter gene expression. Using a simple model, we predict stress-induced reporter gene expression from single-cell translocation dynamics. We then demonstrate that the response of natural target genes to dynamical modulation of Msn2 translocation is...

410

Prediction of radiation induced hardening of reactor pressure vessel steels using artificial neural networks  

In this paper, we use an artificial neural network approach to obtain predictions of neutron irradiation induced hardening, more precisely of the change in the yield stress, for reactor pressure vessel steels of pressurized water nuclear reactors. Different training algorithms are proposed and compared, with the goal of identifying the best procedure to follow depending on the needs of the user. The numerical importance of some input variables is also studied. Very accurate numerical regressions are obtained, by taking only four input variables into account: neutron fluence, irradiation temperature, and chemical composition (Cu and Ni content). Accurate extrapolations in term of neutron fluence are obtained.

411

Artificial neural networks for classification in metabolomic studies of whole cells using 1H nuclear magnetic resonance.  

We report the successful classification, by artificial neural networks (ANNs), of (1)H NMR spectroscopic data recorded on whole-cell culture samples of four different lung carcinoma cell lines, which display different drug resistance patterns. The robustness of the approach was demonstrated by its ability to classify the cell line correctly in 100% of cases, despite the demonstrated presence of operator-induced sources of variation, and irrespective of which spectra are used for training and for validation. The study demonstrates the potential of ANN for lung carcinoma classification in realistic situations. PMID:20886062

412

Characterization of vertical electric fields and associated voltages induced on a overhead power line from close artificially initiated lightning  

Measurements were characterized of simultaneous vertical electric fields and voltages induced at both ends of a 448 m overhead power line by artificially initiated lightning return strokes. The lightning discharges struck ground about 20 m from one end of the line. The measured line voltages could be grouped into two categories: those in which multiple, similarly shaped, evenly spaced pulses were observed, which are called oscillatory; and those dominated by a principal pulse with subsidiary oscillations of much smaller amplitude, which are called impulsive. Voltage amplitudes range from tens of kilovolts for oscillatory voltages to hundreds of kilovolts for impulsive voltages.

413

Computing the mobility of grain boundaries.  

As current experimental and simulation methods cannot determine the mobility of flat boundaries across the large misorientation phase space, we have developed a computational method for imposing an artificial driving force on boundaries. In a molecular dynamics simulation, this allows us to go beyond the inherent timescale restrictions of the technique and induce non-negligible motion in flat boundaries of arbitrary misorientation. For different series of symmetric boundaries, we find both expected and unexpected results. In general, mobility increases as the grain boundary plane deviates from (111), but high-coincidence and low-angle boundaries represent special cases. These results agree with and enrich experimental observations.

414

Hypothermia after Reperfusion Suppresses Aggravation of Acute Brain Edema following Transient Forebrain Ischemia in Mice  

In our previous paper, we reported that spontaneous hypothermia (HT) during ischemia protects against delayed neuronal death in the hippocampus but not against acute brain edema following transient forebrain ischemia, which is induced by occlusion of the bilateral common carotid arteries (BCCA) in C57BL/6J mice. We here demonstrate that artificial HT after reperfusion (rHT) suppresses the aggravation of acute brain edema in the BCCA occlusion C57BL/6J mouse model. Our results suggest that mechanisms regulated by rHT are involved in the attenuation of acute brain edema after reperfusion in this model of cerebral ischemia.   

415

Artificial geochemical barriers for additional recovery of non-ferrous metals and reduction of ecological hazard from the mining industry waste.  

Laboratory tests and physical-chemical modeling have determined that mixtures of activated silica and carbonatite, serpophite and carbonatite show considerable promise for developing artificial geochemical barriers. The obtained average contents of nickel and copper deposited on geochemical barriers in the formed mining induced ores are acceptable for their subsequent cost efficient processing using either pyro- or hydrometallurgy methods. Some tests of geochemical barriers have been carried out, involving the use of polluted water in the impact zone of the "Kol'skaya GMK" JSC. A possibility of water purification from heavy metals down to the MAC level for fishery water bodies has been displayed. PMID:22029700

416

Development of Eddy Current Technique for Reactor In-Core Flux Thimble Wear  

Since in-core flux thimble tube wear the due to flow-induced vibration could degrade the integrity of nuclear reactor, the effective detection and interpretation of the wear is important. In order to establish an inspection technique for thimble tubes, an eddy current experiment was performed to determine the optimum test frequency, defect sensitivity and evaluation accuracy. Eddy current probes were designed and fabricated with a theory. Specimens with artificial defects were fabricated using electro discharge machining method. The results from inspection technique developed and on-site inspection showed good applicability

417

Embryonic Stem Cells: A Novel Attractive Research Tool for Germ Cell Development  

Despite recent astonishing advances in the treatment of infertility by assisted reproductive technology (ART), the fundamental approaches to solving complete infertility due to congenital absence of germ cells or impaired fertility arising from gonadotoxic therapies during prepubertal childhood still remain unclear. Current findings in stem cell biology have resulted in new possibilities for the treatment of reproductive diseases, i.e., germ cell formation may be inducible in vitro. The idea of generating artificial germ cells or gametes may lead to a solution for the treatment of infertility. In this article, we review the recent advances in research into formation of primordial germ cells (PGCs), which are the precursors of gametes, in vitro.   

418

Long term culture of cells patterned on glass via membrane-tethered oligonucleotides  

Oligonucleotide-based membrane inserts can be used as tethers to control attachment of cells to patterned surfaces without interfering with internal cytoskeletal modes of adhesion. Such control can be employed as a means for study of cell-cell interactions or side-by-side co-culture of different cell types without separation/sorting. While there is utility for cell patterning methods decoupled from natural cytoskeletal mechanisms, the consequences of maintaining this artificially induced state of attachment remains unexplored. We present a method for the 2-dimensional patterning of cells via hybridization of membrane-tethered single stranded oligonucleotides to complimentary single stranded oligonucleotides bound to optically transparent glass substrates which allowed us to characterize th...

419

Formation of a misorientation band in the elastic field of a disclination dipole  

The formation of a misorientation band in the elastic field of a disclination dipole is considered and simulated using a kinetic approach. The dipole is artificially located on a grain boundary or induced by plastic deformation on a double ledge in a grain boundary in a bicrystal. The simulation results agree well with the results obtained earlier in a continuum approximation. The dislocation structure of the misorientation band that forms during accommodation slip is shown to be a dynamic steady-state structure, and its appearance has a kinetic nature.

420

Formation of a misorientation band in the elastic field of a disclination dipole  

The formation of a misorientation band in the elastic field of a disclination dipole is considered and simulated using a kinetic approach. The dipole is artificially located on a grain boundary or induced by plastic deformation on a double ledge in a grain boundary in a bicrystal. The simulation results agree well with the results obtained earlier in a continuum approximation. The dislocation structure of the misorientation band that forms during accommodation slip is shown to be a dynamic steady-state structure, and its appearance has a kinetic nature.

 
 
 
 
421

New isolates of carnation Italian ringspot virus differ from the original one by having replication-associated proteins with a typical tombusvirus-like N-terminus and by inducing peroxisome- rather than mitochondrion-derived multivesicular bodies  

Five new isolates of carnation Italian ringspot virus (CIRV) from cherry trees, Gypsophila and surface water differ from the original carnation isolate (CIRV-car) and also from Pelargonium necrotic spot virus (PelNSV) by having an ORF 1/ORF1-RT with a typical tombusvirus-like 5?end and by inducing the formation of peroxisome- rather than mitochondrion-derived multivesicular bodies (MVBs). This supports with natural isolates earlier conclusions reached by others with artificially produced hybrid viruses that the 5?end of ORF 1 determines from which organelle the MBVs will be derived. CIRV-car might have resulted from a natural recombination event with genome elements of a PelNSV-like virus.

422

Implementation and Evaluation of Multiple Adaptive Control Technologies for a Generic Transport Aircraft Simulation  

Presented here is the evaluation of multiple adaptive control technologies for a generic transport aircraft simulation. For this study, seven model reference adaptive control (MRAC) based technologies were considered. Each technology was integrated into an identical dynamic-inversion control architecture and tuned using a methodology based on metrics and specific design requirements. Simulation tests were then performed to evaluate each technology s sensitivity to time-delay, flight condition, model uncertainty, and artificially induced cross-coupling. The resulting robustness and performance characteristics were used to identify potential strengths, weaknesses, and integration challenges of the individual adaptive control technologies

423

Anisotropic Disorder in High Mobility 2D Heterostructures and its Correlation to Electron Transport  

Surface morphology of high mobility heterostructures is examined and correlated with d.c. transport. {\\it All} samples examined show evidence of lines in the [1$\\bar{1}$0] direction with roughness ranging from small amplitude features to severe anisotropic ridges. Transport in these samples is consistent with that in samples having artificially induced 1D charge modulations. The native surface properties reflect a prevalent, anisotropic disorder affecting 2D electron conduction. Importantly, the native lines are orthogonal to the stripes theoretically proposed to explain high Landau level transport anisotropies.

424

Synthetic biology for mammalian cell technology and materials sciences.  

The synthetic reconstruction of natural gene networks and the de novo design of artificial genetic circuits provide new insights into the cell's regulatory mechanisms and will open new opportunities for drug discovery and intelligent therapeutic schemes. We will present how modular synthetic biology tools like repressors, promoters and enzymes can be assembled into complex systems in order to discover small molecules to shut off antibiotic resistance in tubercle bacteria and to design self-sufficient therapeutic networks. The transfer of these synthetic biological modules to the materials science field enables the construction of novel drug-inducible biohybrid materials for biomedical applications. PMID:22286074

425

Search-Free Codebook Mapping for Artificial Bandwidth Extension  

A new codebook mapping algorithm for artificial bandwidth extension (ABE) is introduced in this paper. We design a wideband line spectrum pair (LSP) codebook which is coupled with the same index as the LSP codebook of a narrowband speech codec. The received narrowband LSP codebook indices are used to directly induce wideband LSP codewords. Thus, the proposed scheme eliminates codebook search processing to estimate the wideband spectrum envelope. We apply the proposed scheme to bandwidth extension in adaptive multi-rate (AMR) compressed domain. Its performance is assessed via the perceptual evaluation of speech quality (PESQ), informal listening tests, and weighted million operations per second (WMOPS) calculations.

426

Recent Attempts to Measure the General Relativistic Lense-Thirring Effect with Natural and Artificial Bodies in the Solar System  

According to general relativity, a spinning body of mass M and angular momentum S, like a star or a planet, generates a gravitomagnetic field which induces, among other phenomena, also the Lense-Thirring effect, i.e. secular precessions of the path of a test particle orbiting it. Direct and indisputable tests of such a relativistic prediction are still missing. We discuss some performed attempts to measure it in the gravitational fields of several bodies in the Solar System with natural and artificial objects. The focus is on the realistic evaluation of the impact of some competing classical forces regarded as sources of systematic uncertainties degrading the total accuracy obtainable.

427

Properties of light induced EPR signals in enamel and their possible interference with gamma-induced signals  

Exposure of enamel to UV light (sunlight and artificial) results in EPR signals with g-factors of 2.0018 (perpendicular),1.9975 (parallel), 2.0045, 20052, and 2.0083. The first two signals correspond to the components of the radiation induced signal and the third signal corresponds to the native signal reported in dosimetry and dating studies. The remaining signals were found to be stable and sensitive to both gamma and sunlight exposure. Their sensitivity response to light and radiation was considerably different which gives rise to the possibility that the g=2.0052 and g=2.0083 signals might be used as indicators of the dose resulting from light exposure.

428

Technical and economic feasibility of the use of discharge lamps in replacement of filament for induction of photoperiod in chrysanthemum seedlings production; Viabilidade tecnico-economica do uso de lampadas de descarga em substituicao as de filamento para inducao de fotoperiodo na producao de mudas de crisantemos  

Due to its physiological characteristics, the seedlings of chrysanthemums require supplemental light to prevent bud formation, that is done at night. This article examines the technical and economic valuation to replace the current technology of artificial lighting used by producers (incandescent bulbs) for the purpose of inducing photoperiod in a protected environment for cutting-discharge lamps, with the goal of reducing the consumption electricity used in the process. The analysis showed that the integrated compact fluorescent yellow lamp 23W is the technically and economically feasible for such replacement. (author)

429

Radiation-induced defects in clay minerals: A review  

Extensive information has been collected on radiation effects on clay minerals over the last 35years, providing a wealth of information on environmental and geological processes. The fields of applications include the reconstruction of past radioelement migrations, the dating of clay minerals or the evolution of the physico-chemical properties under irradiation. The investigation of several clay minerals, namely kaolinite, dickite, montmorillonite, illite and sudoite, by Electron Paramagnetic Resonance Spectroscopy has shown the presence of defects produced by natural or artificial radiations. These defects consist mostly of electron holes located on oxygen atoms of the structure. The various radiation-induced defects are differentiated through their nature and their thermal stability. Mos...

430

Electron transfer reactions in microporous solids  

Basic thrust the research program involves use of microporous solids (zeolites, clays, layered and tunnel structure oxide semiconductors) as organizing media for artificial photosynthetic systems. Purpose of the microporous solid is twofold. First, it induces spatial organization of photoactive and electroactive components (sensitizers, semiconductor particles, electron relays, and catalysts) at the solid-solution interface, enhancing the quantum efficiency of charge separation and separating physically the ultimate electron donor and acceptor in the electron transport chain. Second, since the microcrystalline solid admits only molecules of a certain charge and size, it is possible to achieve permanent charge separation by sieving chemical photoproducts (e.g., H[sub 2] and I[sub 3][sup [minus

431

Bio-inspired vision  

Nature still outperforms the most powerful computers in routine functions involving perception, sensing and actuation like vision, audition, and motion control, and is, most strikingly, orders of magnitude more energy-efficient than its artificial competitors. The reasons for the superior performance of biological systems are subject to diverse investigations, but it is clear that the form of hardware and the style of computation in nervous systems are fundamentally different from what is used in artificial synchronous information processing systems. Very generally speaking, biological neural systems rely on a large number of relatively simple, slow and unreliable processing elements and obtain performance and robustness from a massively parallel principle of operation and a high level of redundancy where the failure of single elements usually does not induce any observable system performance degradation. In the late 1980`s, Carver Mead demonstrated that silicon VLSI technology can be employed in implementing ``neuromorphic'' circuits that mimic neural functions and fabricating building blocks that work like their biological role models. Neuromorphic systems, as the biological systems they model, are adaptive, fault-tolerant and scalable, and process information using energy-efficient, asynchronous, event-driven methods. In this paper, some basics of neuromorphic electronic engineering and its impact on recent developments in optical sensing and artificial vision are presented. It is demonstrated that bio-inspired vision systems have the potential to outperform conventional, frame-based vision acquisition and processing systems in many application fields and to establish new benchmarks in terms of redundancy suppression/data compression, dynamic range, temporal resolution and power efficiency to realize advanced functionality like 3D vision, object tracking, motor control, visual feedback loops, etc. in real-time. It is argued that future artificial vision systems, if they are to succeed in demanding applications such as autonomous robot navigation, micro-manipulation or high-speed tracking, must exploit the power of the asynchronous, frame-free, biomimetic approach.

432

Selective Photothermolysis to target Sebaceous Glands: Theoretical Estimation of Parameters and Preliminary Results Using a Free Electron Laser  

The success of permanent laser hair removal suggests that selective photothermolysis (SP) of sebaceous glands, another part of hair follicles, may also have merit. About 30% of sebum consists of fats with copious CH2 bond content. SP was studied in vitro, using free electron laser (FEL) pulses at an infrared CH2 vibrational absorption wavelength band. Absorption spectra of natural and artificially prepared sebum were measured from 200 nm to 3000 nm, to determine wavelengths potentially able to target sebaceous glands. The Jefferson National Accelerator superconducting FEL was used to measure photothermal excitation of aqueous gels, artificial sebum, pig skin, human scalp and forehead skin (sebaceous sites). In vitro skin samples were exposed to FEL pulses from 1620 to 1720 nm, spot diameter 7-9.5 mm with exposure through a cold 4C sapphire window in contact with the skin. Exposed and control tissue samples were stained using H and E, and nitroblue tetrazolium chloride staining (NBTC) was used to detect thermal denaturation. Natural and artificial sebum both had absorption peaks near 1210, 1728, 1760, 2306 and 2346 nm. Laser-induced heating of artificial sebum was approximately twice that of water at 1710 and 1720 nm, and about 1.5x higher in human sebaceous glands than in water. Thermal camera imaging showed transient focal heating near sebaceous hair follicles. Histologically, skin samples exposed to {approx}1700 nm, {approx}100-125 ms pulses showed evidence of selective thermal damage to sebaceous glands. Sebaceous glands were positive for NBTC staining, without evidence of selective loss in samples exposed to the laser. Epidermis was undamaged in all samples. Conclusions: SP of sebaceous glands appears to be feasible. Potentially, optical pulses at {approx}1720 nm or {approx}1210 nm delivered with large beam diameter and appropriate skin cooling in approximately 0.1 s may provide an alternative treatment for acne.

433

Optimization of auto-induction medium for G-CSF production by Escherichia coli using artificial neural networks coupled with genetic algorithm.  

Granulocyte colony-stimulating factor (G-CSF) is a cytokine widely used in cancer patients receiving high doses of chemotherapeutic drugs to prevent the chemotherapy-induced suppression of white blood cells. The production of recombinant G-CSF should be increased to meet the increasing market demand. This study aims to model and optimize the carbon source of auto-induction medium to enhance G-CSF production using artificial neural networks coupled with genetic algorithm. In this approach, artificial neural networks served as bioprocess modeling tools, and genetic algorithm (GA) was applied to optimize the established artificial neural network models. Two artificial neural network models were constructed: the back-propagation (BP) network and the radial basis function (RBF) network. The root mean square error, coefficient of determination, and standard error of prediction of the BP model were 0.0375, 0.959, and 8.49 %, respectively, whereas those of the RBF model were 0.0257, 0.980, and 5.82 %, respectively. These values indicated that the RBF model possessed higher fitness and prediction accuracy than the BP model. Under the optimized auto-induction medium, the predicted maximum G-CSF yield by the BP-GA approach was 71.66 %, whereas that by the RBF-GA approach was 75.17 %. These predicted values are in agreement with the experimental results, with 72.4 and 76.014 % for the BP-GA and RBF-GA models, respectively. These results suggest that RBF-GA is superior to BP-GA. The developed approach in this study may be helpful in modeling and optimizing other multivariable, non-linear, and time-variant bioprocesses. PMID:23132252

434

Partial gamma-ray production cross sections for (n,xng) reactions in natural argon from 1 - 30 MeV  

Background: Neutron-induced backgrounds are a significant concern for experiments that require extremely low levels of radioactive backgrounds such as direct dark matter searches and neutrinoless double-beta decay experiments. Unmeasured neutron scattering cross sections are often accounted for incorrectly in Monte Carlo simulations. Purpose: Determine partial gamma-ray production cross sections for (n,xng) reactions in natural argon for incident neutron energies between 1 and 30 MeV. Methods: The broad spectrum neutron beam at the Los Alamos Neutron Science Center (LANSCE) was used used for the measurement. Neutron energies were determined using time-of-flight and resulting gamma rays from neutron-induced reactions were detected using the GErmanium Array for Neutron Induced Excitations (GEANIE). Results: Partial gamma-ray cross sections were measured for six excited states in Ar-40 and two excited states in Ar-39. Measured (n,xng) cross sections were compared to the TALYS nuclear reaction code. Conclusions: ...

435

Final report of the TRUE Block Scale project. 2. Tracer tests in the block scale  

The tracer test programme of the TRUE Block Scale Project involved 14 tracer tests campaigns, including performance of 32 tracer injections in 16 different combinations of source and sink sections (flow paths) varying in length between 10 to 130 metres, and involving one or more structures. Average, travel times varied between 1.5 and >2000 hours. Tracer dilution tests performed in conjunction with cross-hole hydraulic pumping tests were found to be a very important part of the pre-tests, where the results were used to identify and screen among possible injection points, and to verify the hydrostructural model valid at a given time. The main problem faced in the block scale tests was to select a test geometry, which gave a sufficiently high mass recovery, and at the same time enabled performance of cross-hole sorbing tracer tests within reasonable time frames. Three different injection methods were applied during the test programme; decaying pulse, finite pulse and forced pulse (unequal dipole). During the later phases of the tracer test programme it was identified that forced injection had to be employed in order to enable detection of tracer at the sink due to strong dilution, and also to avoid problems with artificially induced tailing in the injection signal. Sorbing (reactive) tracers were selected among the radioactive isotopes of the alkali and alkaline earth metals previously used in the TRUE- 1 experiments. It was decided that at least one slightly sorbing tracer and one strongly sorbing tracer should be used in each injection. Non-sorbing tracers were used for conservative reference, e.g., {sup 82}Br{sup -}, {sup 186}ReO{sub 4}, HTO (tritiated water) and {sup 131}I{sup -}. In two of the injections the radioactive non-sorbing tracers were rather short-lived and Uranine and Naphthionate were used as complementary conservative tracers. Surface distribution coefficients, K{sub a}, were evaluated from TRUE-1 and TRUE Block Scale data, making use of the retardation noted in the injection. The evaluated K{sub a} values were found to be of a magnitude equitable to the TRUE- 1 laboratory K{sub a} values. Effects of matrix diffusion, sorption kinetics model, non-linear sorption were also explored. The evaluation and interpretation of the block scale tracer breakthrough curves indicated response of a heterogeneous system, observed both from tests in single structures and in network of structures. Results from the deterministic Structure 20 were found to show a signature of a narrow and high-conductive single structure, whereas results from Structure 21 indicated that it is probably more complex than assumed at the onset of the investigation, probably made up of several sub-parallel structures, rather than a single fracture. The network flow paths generally have less steep tails (t{sup -4/2} - t{sup -3/2}) in log-log space than the single structure flow paths. The observed order of retention among the different species was found to be the same as in TRUE-1 and in the laboratory tests, i.e. Na{sup +}<Ca{sup 2{approx_equal}}Sr{sup 2+}<Ba{sup 2+}{approx_equal}Rb{sup +}<Cs{sup +}. Another similarity was tha the retardation, expressed as the ratio of the time at which 50% of the sorbing tracer was recovered compared to the conservative tracer (R{sub 50%}), was about the same for most species when comparing TRUE-1 data to the results of 17 m single structure flow paths (C1 and C4) in Structure 20. However, for the breakthroughs of sorbing tracers in the more complex flow paths C3 (Na{sup +}) and C2(Ca{sup 2+}) a 30-80% stronger retardation (expressed as R{sub 50%}) was noted. The reasons for this somewhat enhanced retardation between the two slower and more complicated flow paths (C2 and C3) and the single structure flow paths (C 1 and C4) may be several; e.g. presence of gouge material (fine-grained fault gouge) in the structures, presence of gouge material in fracture intersection zones, differences in the mineralogy along the flow paths, larger portions of stagnant water to interact with along the flow path, higher porosity in the fracture rim zone.

436

Status of LDEF ionizing radiation measurements and analysis  

At this symposium significant new data and analyses were reported in cosmic ray research, radiation dosimetry, induced radioactivity, and radiation environment modeling. Measurements of induced radioactivity and absorbed dose are nearly complete, but much analysis and modeling remains. Measurements and analyses of passive nuclear track detectors (PNTD), used to derive the cosmic ray composition and spectra, and linear energy transfer (LET) spectra, are only a few percent complete, but important results have already emerged. As one might expect at this stage of the research, some of the new information has produced questions rather than answers. Low-energy heavy nuclei detected by two experiments are not compatible with known solar or cosmic components. Various data sets on absorbed dose are not consistent, and a new trapped proton environment model does not match the absorbed dose data. A search for cosmogenic nuclei other than Be-7 on Long Duration Exposure Facility (LDEF) surfaces has produced an unexpected result, and some activation data relating to neutrons is not yet understood. Most of these issues will be resolved by the analysis of further experiment data, calibrations, or the application of the large LDEF data set that offers alternate data or analysis techniques bearing on the same problem. The scope of the papers at this symposium defy a compact technical summary. I have attempted to group the new information that I noted into the following groups: induced radioactivity; absorbed dose measurements; LET spectra and heavy ion dosimetry; environment modeling and three dimensional shielding effects; cosmogenic nuclei; and cosmic rays and other heavy ions. The papers generally are expository and have excellent illustrations, and I refer to their figures rather than reproduce them here. The general program and objectives of ionizing radiation measurements and analyses on LDEF has been described previously.

437

Assessment of the genotoxicity of {sup 137}Cs radiation using Vicia-micronucleus, Tradescantia-micronucleus and Tradescantia-stamen-hair mutation bioassays  

Since the middle of the 20th century, ionizing radiations from radioactive isotopes including {sup 137}Cs have been investigated to determine their genotoxic impact on living organisms. The present study was designed to compare the effectiveness of three plant bioassays to assess DNA damage induced by low doses of {sup 137}Cs: Vicia-micronucleus test (Vicia-MCN), Tradescantia-micronucleus test (Trad-MCN) and Tradescantia-stamen-hair mutation test (Trad-SH) were used. Vicia faba (broad bean) and Tradescantia clone 4430 (spiderwort) were exposed to {sup 137}Cs according to different scenarios: external and internal (contamination) irradiations. Experiments were conducted with various levels of radioactivity in solution or in soil, using solid or liquid {sup 137}Cs sources. The three bioassays showed different sensitivities to the treatments. Trad-MCN appeared to be the most sensitive test (significative response from 1.5 kBq/200 ml after 30 h of contamination). Moreover, at comparable doses, internal irradiations led to larger effects for the three bioassays. These bioassays are effective tests for assessing the genotoxic effects of radioactive {sup 137}Cs pollution.

438

Assessment of the genotoxicity of 137Cs radiation using Vicia-micronucleus, Tradescantia-micronucleus and Tradescantia-stamen-hair mutation bioassays.  

Since the middle of the 20th century, ionizing radiations from radioactive isotopes including 137Cs have been investigated to determine their genotoxic impact on living organisms. The present study was designed to compare the effectiveness of three plant bioassays to assess DNA damage induced by low doses of 137Cs: Vicia-micronucleus test (Vicia-MCN), Tradescantia-micronucleus test (Trad-MCN) and Tradescantia-stamen-hair mutation test (Trad-SH) were used. Vicia faba (broad bean) and Tradescantia clone 4430 (spiderwort) were exposed to 137Cs according to different scenarios: external and internal (contamination) irradiations. Experiments were conducted with various levels of radioactivity in solution or in soil, using solid or liquid 137Cs sources. The three bioassays showed different sensitivities to the treatments. Trad-MCN appeared to be the most sensitive test (significative response from 1.5 kBq/200 ml after 30 h of contamination). Moreover, at comparable doses, internal irradiations led to larger effects for the three bioassays. These bioassays are effective tests for assessing the genotoxic effects of radioactive 137Cs pollution. PMID:15795031