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Sample records for dutch elm disease

  1. Dutch elm disease

    Treesearch

    James W. Walters

    1992-01-01

    Since its discovery in the United States in 1930, Dutch elm disease has killed thousands of native elms. The three native elms, American, slippery, and rock, have little or no resistance to Dutch elm disease, but individual trees within each species vary in susceptibility to the disease. The most important of these, American elm, is scattered in upland stands but is...

  2. HOW to Differentiate Dutch Elm Disease from Elm Phloem Necrosis

    Treesearch

    Lester Paul Gibson; Arthur R. Hastings; Leon A. LeMadeliene

    1981-01-01

    Dutch elm disease (DED) and elm phloem necrosis are the two most serious diseases of elm in the United States (Figs. 1 and 2). Most native species of elm are susceptible to both diseases. Dutch elm disease is caused by a fungus, Ceratocystis u1mi (Buisman) C. Moreau, and is transmitted by two species of elm bark beetles-the smaller European elm bark beetle, Scolytus...

  3. Dutch Elm Disease (DED) and the American Elm (Pest Alert)

    Treesearch

    USDA Forest Service

    1999-01-01

    For decades the American elm was one of our most treasured trees, gracing streets and parks of many cities with beautiful form and dense foliage. The American elm was particularly well suited to urban sites because it grows quickly, is long-lived, and is tolerant of compacted soils and air pollution. However, in most communities Dutch elm disease (DED) killed a...

  4. Elms and Dutch elm disease: a quick overview

    Treesearch

    Michael. Marcotrigiano

    2017-01-01

    In the 1930s Dutch elm disease (DED) was accidentally introduced from Europe into the United States. It had a devastating impact on American elm (Ulmus americana) and its relatives in urban and riparian environments. In the United States, the three-part pathosystem for DED is unique in that the affected elm species are North American, the pathogen originated in Asia,...

  5. Modeling elm growth and Dutch elm disease susceptibility

    Treesearch

    Alberto Santini; Luisa Ghelardini

    2012-01-01

    Elm susceptibility to Dutch elm disease (DED) displays strong seasonal variation. The period during which elms can become infected and express DED symptoms is generally restricted to several weeks after growth resumption in spring, although it can vary among species, provenances, and environmental conditions. The reason for this phenomenon is not understood, but the...

  6. The Italian elm breeding program for Dutch elm disease resistance

    Treesearch

    Alberto Santini; Francesco Pecori; Luisa Ghelardini

    2012-01-01

    In the 20th century, elms across Europe and North America were devastated by two pandemics of Dutch elm disease (DED), caused by the introduction of two fungal pathogens: Ophiostoma ulmi, followed by O. novo-ulmi. At the end of 1920s, research into a resistance to DED began in Europe and then in the United States. No...

  7. Elm genetic diversity and hybridization in the presence of Dutch elm disease

    Treesearch

    Johanne Brunet; Raymond P. Guries

    2017-01-01

    The impact of Dutch elm disease (DED) on the genetic diversity of slippery elm (Ulmus rubra) is summarized and its potential impact on the genetic diversity of other North American native elms, American elm (U. americana), rock elm (U. thomasii), winged elm (U. alata), cedar elm (

  8. Dutch Elm Disease Control: Intensive Sanitation and Survey Economics

    Treesearch

    William N., Jr. Cannon; Jack H. Barger; David P. Worley

    1977-01-01

    Recent research has shown that prompt removal of diseased elms reduces the incidence of Dutch elm disease more than sanitation practice that allows diseased elms to remain standing into the dormant season. The key to prompt removal is repeated surveys to detect diseased elms as early as possible. Intensive sanitation can save more elms and cost less than the more...

  9. HOW to Save Dutch Elm Diseased Trees by Pruning

    Treesearch

    J.R. Allison; G.F. Gregory

    1979-01-01

    Dutch elm disease (DED), caused by the fungus, Ceratocystis ulmi, is the most devastating shade tree disease in the United States. Healthy elms can become diseased by 1) elm bark beetles that carry the fungus from elm to elm, or 2) through root grafting with already infected trees. Along with wilt symptoms, streaking (sapwood discoloration), a characteristic internal...

  10. Dutch elm disease control: performance and costs

    Treesearch

    William N., Jr. Cannon; David P. Worley

    1980-01-01

    Municipal programs to suppress Dutch elm disease have had highly variable results. Performance as measured by tree mortality was unrelated to control strategies. Costs for control programs were 37 to 76 percent less than costs without control programs in the 15-year time-span of the study. Only those municipalities that conducted a high-performance program could be...

  11. Dutch elm disease control: performance and costs

    Treesearch

    William N., Jr. Cannon; David P. Worley

    1976-01-01

    Municipal programs to suppress Dutch elm disease have had highly variable results. Performance as measured by tree mortality was unrelated to control strategies. Costs for control programs were 37 to 76 percent less than costs without control programs in the 15-year time-span of the study. Only those municipalities that conducted a high-performance program could be...

  12. Dutch Elm Disease and Methoxychlor

    Treesearch

    Jack H. Barger

    1976-01-01

    American elm trees, Ulmus americana L., in Milwaukee, Wisconsin, were sprayed with methoxychlor by helicopter or mist blower once each year for 3 years to control the smaller European elm bark beetle Scolytus multistriatus (Marsham). Twig crotches were collected from sprayed trees each year for bioassay. Methoxychlor residues...

  13. Dutch elm disease pathogen transmission by the banded elm bark beetle Scolytus schevyrewi

    Treesearch

    W. R. Jacobi; R. D. Koski; J. F. Negron

    2013-01-01

    Dutch Elm Disease (DED) is a vascular wilt disease of Ulmus species (elms) incited in North America primarily by the exotic fungus Ophiostoma novo-ulmi. The pathogen is transmitted via root grafts and elm bark beetle vectors, including the native North American elm bark beetle, Hylurgopinus rufipes and the exotic smaller European elm bark beetle, Scolytus multistriatus...

  14. Elm genetic diversity and hybridization in the presence of Dutch elm disease

    USDA-ARS?s Scientific Manuscript database

    Dutch elm disease (DED) has devastated native North American elm species for more than 75 years. The impact of DED on the genetic diversity of one native elm species, U. rubra or slippery elm, is summarized and its potential impact on the genetic diversity of the other four North American native elm...

  15. HOW to Identify and Manage Dutch Elm Disease

    Treesearch

    Linda Haugen

    1998-01-01

    At one time, the American elm was considered to be an ideal street tree because it was graceful, long-lived, fast growing, and tolerant of compacted soils and air pollution. Then Dutch elm disease (DED) was introduced and began devastating the elm population. Estimates of DED losses of elm in communities and woodlands across the U.S. are staggering (figure 1). Because...

  16. Genotype x environment interaction and growth stability of several elm clones resistant to Dutch elm disease

    Treesearch

    Alberto Santini; Francesco Pecori; Alessia L. Pepori; Luisa Ghelardini

    2012-01-01

    The elm breeding program carried out in Italy at the Institute of Plant Protection - Consiglio Nazionale delle Ricercje (CNR) during the last 40 years aimed to develop Dutch elm disease (DED)-resistant elm selections specific to the Mediterranean environment. The need for genotypes adapted to Mediterranean conditions was evident from the poor performance of the Dutch...

  17. Do mites phoretic on elm bark beetles contribute to the transmission of Dutch elm disease?

    Treesearch

    John Moser; Heino Konrad; Stacy Blomquist; Thomas Kirisits

    2010-01-01

    Dutch elm disease (DED) is a destructive vascular wilt disease of elm (Ulmus) trees caused by the introduced Ascomycete fungus Ophiostoma novo-ulmi. In Europe, this DED pathogen is transmitted by elm bark beetles in the genus Scolytus. These insects carry phoretic mites to new, suitable habitats. The aim of this...

  18. Improved Sanitation Practice for Control of Dutch Elm Disease

    Treesearch

    Jack H. Barger

    1977-01-01

    In Detroit, Michigan, 12 plots, each containing about 600 American elm trees, Ulmus americana L., were subjected for 3 years to intensive and conventional sanitation treatments to control Dutch elm disease. In the intensive treatment, three disease surveys were conducted each year; each followed by tree removal within 20 working days. In the...

  19. American elm clones of importance in Dutch elm disease tolerance studies

    Treesearch

    Linda M. Haugen; Susan E. Bentz

    2017-01-01

    We present the background and characteristics of American elm clones that are commercially available or of interest in research on Dutch elm disease (DED) tolerance in the United States. The characteristics of interest include origin, ploidy level, whether available in nursery trade, evidence of DED tolerance, and other comments. The list includes 10 named commercially...

  20. Generation of American elm trees with tolerance to Dutch elm disease through controlled crosses and selection

    Treesearch

    James M. Slavicek; Kathleen S. Knight

    2012-01-01

    The goal of our research and development efforts is to generate new and/or improved selections of the American elm (Ulmus americana L.) with tolerance/resistance to Dutch elm disease (DED). The approaches we are taking for this effort include: 1) controlled breeding using known DED -tolerant selections, 2) controlled breeding using DED-tolerant...

  1. Using Dutch elm disease-tolerant elm to restore floodplains impacted by emerald ash borer

    Treesearch

    Kathleen S. Knight; James M. Slavicek; Rachel Kappler; Elizabeth Pisarczyk; Bernadette Wiggin; Karen. Menard

    2012-01-01

    American elm (Ulmus Americana L.) was a dominant species in floodplains and swamps of the Midwest before Dutch elm disease (DED) (Ophiostoma ulmi and O.novo-ulmi) reduced its populations. In many areas, ash (Fraxinus spp.) became dominant in these ecosystems. Emerald ash borer (EAB) (...

  2. Birds and Dutch elm disease control

    USGS Publications Warehouse

    DeWitt, J.B.

    1958-01-01

    Brief, factual review of information on effect of DDT and other insecticides on birds. One program for control of elm disease caused 22% decrease in number of adult birds and 56% mortality of nestlings. Quail fed 3 oz. of DDT per ton of food had 16% reduction in young hatched and 500% increase in defective chicks. Quail fed same dosage during winter and breeding seasons had 30% decrease in fertile eggs and 800% increase in defective chicks. More than 90% of their chicks died in first 6 weeks although fed no insecticide. Almost equally bad results came from feeding Pheasants diets with about 1 oz. DDT per ton. Other common insecticides (chlorinated hydrocarbons) also caused lowered chick survival and higher percentages of crippled chicks. From field data we know that 2 lbs. DDT/acre can affect birds and has even worse effects on cold-blooded animals. Efforts to control elm disease have left as much as 196 lbs. DDT/acre in top 3 inches of soil. Earthworms concentrate DDT in their tissues. Thus the treated areas can be traps for birds and other animals. What can be done? 1) In control of elm disease, use minimum effective amount of insecticide; mist blowers use less than sprayers. 2) Avoid applications during migration and nesting seasons. It has been reported that adequate control can be obtained with dormant sprays and that foliar applications may not be required. Tables of this paper show effects of DDT on reproduction of Quail, relative toxicity to quail of 8 insecticides, and amounts of 7 insecticides required to cause 40% or more decrease in Quail reproduction. These comparisons demonstrate that Aldrin, Endrin, and Dieldrin are 20 to 200 times as toxic as DDT and that Heptachlor and Chlordane are only slightly less toxic than Dieldrin. Methoxychlor and Strobane are less toxic to Quail than is DDT.

  3. Elm diseases

    Treesearch

    John W. Peacock

    1989-01-01

    Dutch elm disease was found in Cleveland, Ohio, in 1930, and is now in most of the contiguous 48 states. The disease is caused by a fungus that has killed millions of wild and planted elms. Losses have been the greatest in the eastern United States. The fungus attacks all elms, but our native species, American, slippery, and rock elm have little or no resistance to the...

  4. Genome-wide analyses of the Dutch elm disease fungi

    Treesearch

    Louis. Bernier

    2017-01-01

    The Ascomycete fungi Ophiostoma ulmi and O. novo-ulmi are the pathogens respectively responsible for the two successive pandemics of Dutch elm disease (DED) since the early 1900s. The advent of the highly fit and virulent O. novo-ulmi was a landmark event in the evolution of DED during the last 100 years....

  5. Fungicide Injection to Control Dutch Elm Disease: Understanding the Options

    Treesearch

    Linda Haugen; Mark Stennes

    1999-01-01

    In some situations, injecting trees with fungicides is an effective treatment for the management of Dutch elm disease (DED). Several injection products are on the market, and various means of application are recommended. Each product and method has pros and cons. The "best" product depends on the individual tree? its current condition, the objectives of the...

  6. Leaf trait dissimilarities between Dutch elm hybrids with a contrasting tolerance to Dutch elm disease

    PubMed Central

    Ďurkovič, Jaroslav; Čaňová, Ingrid; Lagaňa, Rastislav; Kučerová, Veronika; Moravčík, Michal; Priwitzer, Tibor; Urban, Josef; Dvořák, Miloň; Krajňáková, Jana

    2013-01-01

    Background and Aims Previous studies have shown that Ophiostoma novo-ulmi, the causative agent of Dutch elm disease (DED), is able to colonize remote areas in infected plants of Ulmus such as the leaf midrib and secondary veins. The objective of this study was to compare the performances in leaf traits between two Dutch elm hybrids ‘Groeneveld’ and ‘Dodoens’ which possess a contrasting tolerance to DED. Trait linkages were also tested with leaf mass per area (LMA) and with the reduced Young's modulus of elasticity (MOE) as a result of structural, developmental or functional linkages. Methods Measurements and comparisons were made of leaf growth traits, primary xylem density components, gas exchange variables and chlorophyll a fluorescence yields between mature plants of ‘Groeneveld’ and ‘Dodoens’ grown under field conditions. A recently developed atomic force microscopy technique, PeakForce quantitative nanomechanical mapping, was used to reveal nanomechanical properties of the cell walls of tracheary elements such as MOE, adhesion and dissipation. Key Results ‘Dodoens’ had significantly higher values for LMA, leaf tissue thickness variables, tracheary element lumen area (A), relative hydraulic conductivity (RC), gas exchange variables and chlorophyll a fluorescence yields. ‘Groeneveld’ had stiffer cell walls of tracheary elements, and higher values for water-use efficiency and leaf water potential. Leaves with a large carbon and nutrient investment in LMA tended to have a greater leaf thickness and a higher net photosynthetic rate, but LMA was independent of RC. Significant linkages were also found between the MOE and some vascular traits such as RC, A and the number of tracheary elements per unit area. Conclusions Strong dissimilarities in leaf trait performances were observed between the examined Dutch elm hybrids. Both hybrids were clearly separated from each other in the multivariate leaf trait space. Leaf growth, vascular and gas

  7. Development of new Dutch Elm disease-tolerant selections for restoration of the American Elm in urban and forested landscapes

    Treesearch

    C.C. Pinchot; C.E. Flower; K.S. Knight; C. Marks; R. Minocha; D. Lesser; K. Woeste; P.G. Schaberg; B. Baldwin; D.M. Delatte; T.D. Fox; N. Hayes-Plazolles; B. Held; K. Lehtoma; S. Long; S. Mattix; A. Sipes; J.M. Slavicek

    2017-01-01

    The goal of our research and development efforts is to restore American elm (Ulmus americana) as a species in both natural and urban landscapes. Accomplishing this goal requires identification/generation of additional American elm cultivars that are tolerant to Dutch elm disease (DED) caused by Ophiostoma ulmi and O. novo-ulmi, and development of methods to reintroduce...

  8. Genetic diversity and relationships among Dutch elm disease tolerant Ulmus pumila L. accessions from China

    USDA-ARS?s Scientific Manuscript database

    Elm breeding programs worldwide have relied heavily on Asian elm germplasm, particularly U. pumila, for the breeding of Dutch elm disease tolerant cultivars. However, the extent and patterning of genetic variation in Asian elm species is unknown. Therefore, the objective of this research was to de...

  9. Do mites phoretic on elm bark beetles contribute to the transmission of Dutch elm disease?

    NASA Astrophysics Data System (ADS)

    Moser, John C.; Konrad, Heino; Blomquist, Stacy R.; Kirisits, Thomas

    2010-02-01

    Dutch elm disease (DED) is a destructive vascular wilt disease of elm ( Ulmus) trees caused by the introduced Ascomycete fungus Ophiostoma novo-ulmi. In Europe, this DED pathogen is transmitted by elm bark beetles in the genus Scolytus. These insects carry phoretic mites to new, suitable habitats. The aim of this study was to record and quantify conidia and ascospores of O. novo-ulmi on phoretic mites on the three elm bark beetle species Scolytus multistriatus, Scolytus pygmaeus, and Scolytus scolytus. Spores of O. novo-ulmi were found on four of the ten mite species phoretic on Scolytus spp. These included Elattoma fraxini, Proctolaelaps scolyti, Pseudotarsonemoides eccoptogasteri, and Tarsonemus crassus. All four species had spores attached externally to their body surfaces. However, T. crassus carried most spores within its sporothecae, two paired pocket-like structures adapted for fungal transmission. Individuals of Pr. scolyti also had O. novo-ulmi conidia and ascospores frequently in their digestive system, where they may remain viable. While E. fraxini and P. eccoptogasteri rarely had spores attached to their bodies, large portions of Pr. scolyti and T. crassus carried significant numbers of conidia and/or ascospores of O. novo-ulmi. P. scolyti and T. crassus, which likely are fungivores, may thus contribute to the transmission of O. novo-ulmi, by increasing the spore loads of individual Scolytus beetles during their maturation feeding on twigs of healthy elm trees, enhancing the chance for successful infection with the pathogen. Only S. scolytus, which is the most efficient vector of O. novo-ulmi in Europe, carried high numbers of Pr. scolyti and T. crassus, in contrast to S. multistriatus and S. pygmaeus, which are known as less efficient vectors. The high efficiency of S. scolytus in spreading Dutch elm disease may be partly due to its association with these two mites and the hyperphoretic spores of O. novo-ulmi they carry.

  10. Do mites phoretic on elm bark beetles contribute to the transmission of Dutch elm disease?

    PubMed

    Moser, John C; Konrad, Heino; Blomquist, Stacy R; Kirisits, Thomas

    2010-02-01

    Dutch elm disease (DED) is a destructive vascular wilt disease of elm (Ulmus) trees caused by the introduced Ascomycete fungus Ophiostoma novo-ulmi. In Europe, this DED pathogen is transmitted by elm bark beetles in the genus Scolytus. These insects carry phoretic mites to new, suitable habitats. The aim of this study was to record and quantify conidia and ascospores of O. novo-ulmi on phoretic mites on the three elm bark beetle species Scolytus multistriatus, Scolytus pygmaeus, and Scolytus scolytus. Spores of O. novo-ulmi were found on four of the ten mite species phoretic on Scolytus spp. These included Elattoma fraxini, Proctolaelaps scolyti, Pseudotarsonemoides eccoptogasteri, and Tarsonemus crassus. All four species had spores attached externally to their body surfaces. However, T. crassus carried most spores within its sporothecae, two paired pocket-like structures adapted for fungal transmission. Individuals of Pr. scolyti also had O. novo-ulmi conidia and ascospores frequently in their digestive system, where they may remain viable. While E. fraxini and P. eccoptogasteri rarely had spores attached to their bodies, large portions of Pr. scolyti and T. crassus carried significant numbers of conidia and/or ascospores of O. novo-ulmi. P. scolyti and T. crassus, which likely are fungivores, may thus contribute to the transmission of O. novo-ulmi, by increasing the spore loads of individual Scolytus beetles during their maturation feeding on twigs of healthy elm trees, enhancing the chance for successful infection with the pathogen. Only S. scolytus, which is the most efficient vector of O. novo-ulmi in Europe, carried high numbers of Pr. scolyti and T. crassus, in contrast to S. multistriatus and S. pygmaeus, which are known as less efficient vectors. The high efficiency of S. scolytus in spreading Dutch elm disease may be partly due to its association with these two mites and the hyperphoretic spores of O. novo-ulmi they carry.

  11. Resistance to Dutch Elm Disease Reduces Presence of Xylem Endophytic Fungi in Elms (Ulmus spp.)

    PubMed Central

    Martín, Juan A.; Witzell, Johanna; Blumenstein, Kathrin; Rozpedowska, Elzbieta; Helander, Marjo; Sieber, Thomas N.; Gil, Luis

    2013-01-01

    Efforts to introduce pathogen resistance into landscape tree species by breeding may have unintended consequences for fungal diversity. To address this issue, we compared the frequency and diversity of endophytic fungi and defensive phenolic metabolites in elm (Ulmus spp.) trees with genotypes known to differ in resistance to Dutch elm disease. Our results indicate that resistant U. minor and U. pumila genotypes exhibit a lower frequency and diversity of fungal endophytes in the xylem than susceptible U. minor genotypes. However, resistant and susceptible genotypes showed a similar frequency and diversity of endophytes in the leaves and bark. The resistant and susceptible genotypes could be discriminated on the basis of the phenolic profile of the xylem, but not on basis of phenolics in the leaves or bark. As the Dutch elm disease pathogen develops within xylem tissues, the defensive chemistry of resistant elm genotypes thus appears to be one of the factors that may limit colonization by both the pathogen and endophytes. We discuss a potential trade-off between the benefits of breeding resistance into tree species, versus concomitant losses of fungal endophytes and the ecosystem services they provide. PMID:23468900

  12. Dutch elm disease. (Latest citations from the Life Sciences Collection database). Published Search

    SciTech Connect

    Not Available

    1994-03-01

    The bibliography contains citations concerning the spread and control of Dutch elm disease. Dutch elm disease is a lethal fungal disease in elm trees which is transmitted via bark beetles. Topics included methods to treat the disease and to control the disease-carrying beetle, biochemistry and genetic information on the disease fungus and its phytotoxin, ecological effects of the disease, evidence of fungicide tolerance by the disease fungus, and attempts to breed disease resistant elm trees. Distribution of Dutch elm disease in Iran, Scotland, the United States, Yugoslavia, and Sweden is described. This information is useful, for example, in the development of methods for detection and treatment of Dutch elm disease. (Contains a minimum of 128 citations and includes a subject term index and title list.)

  13. Pressure injection of methyl 2-benzimidazole carbamate hydrochloride solution as a control for Dutch elm disease

    Treesearch

    Garold F. Gregory; Thomas W. Jones

    1973-01-01

    A preliminary evaluation of the effectiveness of injecting methyl 2-benzimidazole carbamate hydrochloride solution into elms for prevention or cure of Dutch elm disease is reported. Symptom development was diminished or prevented in elms injected with fungicide before inoculation. Symptom development was arrested in all crown-inoculated diseased trees injected with the...

  14. Relative importance of root grafts and bark beetles to the spread of Dutch elm disease

    Treesearch

    R. A. Cuthbert; W. N., Jr. Cannon; J. W. Peacock

    1975-01-01

    Root-graft transmission of Dutch elm disease (DED) is sometimes ignored in both research studies and city programs to control DED. Our results indicate that elms adjacent to 1-, 2-, or 3-year-old stumps have a disease rate three to five times higher than elms not adjacent to stumps. We conclude that in Detroit, which has elm plantings typical of many United States...

  15. Bird mortality following DDT spray for Dutch elm disease

    USGS Publications Warehouse

    Wurster, D.H.; Wurster, C.F.; Strickland, W.N.

    1965-01-01

    Avian populations in Hanover, N. H., a town that has sprayed its elms with DDT for many years in an attempt to control Dutch elm disease, were compared with those in Norwich, Vt., a town 1 mile (1.6 km) west of Hanover that has never sprayed. Hanover applied 109 lb DDT/acre (2.1 kg/hectare) in April 1963, then used Methoxychlor in April 1964. Population surveys were taken regularly during spring and early summer of these years, dead birds were collected in both towns, and 106 birds were analyzed for DDT, DDE, and DDD. Severe mortality of both resident and migrant birds occurred in Hanover during spring 1963, and the evidence implicates DDT as its cause. Robin loss was estimated at 70% of the resident population, or 350 to 400 individuals, but mortality among other species of widely varied feeding habits was also substantial. Feeding habits suggest that some birds acquired the toxicant by eating living insects carrying DDT, presenting the paradox of survival of the intended DDT victims, and death, instead, of insectivorous birds. Organ and whole bird analyses are presented and criteria for establishing cause of death are discussed. Most of the DDT had been converted to DDE and DDD, and residues were found in all organs analyzed. Robin mortality was reduced, but not eliminated following Methoxychlor application in 1964; these losses were believed caused by residual DDT in the soil. There was no evidence DDT poisoning among other species in 1964, though the dead birds collected were not analyzed.

  16. Host responses and metabolic profiles of wood components in Dutch elm hybrids with a contrasting tolerance to Dutch elm disease

    PubMed Central

    Ďurkovič, Jaroslav; Kačík, František; Olčák, Dušan; Kučerová, Veronika; Krajňáková, Jana

    2014-01-01

    Background and Aims Changes occurring in the macromolecular traits of cell wall components in elm wood following attack by Ophiostoma novo-ulmi, the causative agent of Dutch elm disease (DED), are poorly understood. The purpose of this study was to compare host responses and the metabolic profiles of wood components for two Dutch elm (Ulmus) hybrids, ‘Groeneveld’ (a susceptible clone) and ‘Dodoens’ (a tolerant clone), that have contrasting survival strategies upon infection with the current prevalent strain of DED. Methods Ten-year-old plants of the hybrid elms were inoculated with O. novo-ulmi ssp. americana × novo-ulmi. Measurements were made of the content of main cell wall components and extractives, lignin monomer composition, macromolecular traits of cellulose and neutral saccharide composition. Key Results Upon infection, medium molecular weight macromolecules of cellulose were degraded in both the susceptible and tolerant elm hybrids, resulting in the occurrence of secondary cell wall ruptures and cracks in the vessels, but rarely in the fibres. The 13C nuclear magnetic resonance spectra revealed that loss of crystalline and non-crystalline cellulose regions occurred in parallel. The rate of cellulose degradation was influenced by the syringyl:guaiacyl ratio in lignin. Both hybrids commonly responded to the medium molecular weight cellulose degradation with the biosynthesis of high molecular weight macromolecules of cellulose, resulting in a significant increase in values for the degree of polymerization and polydispersity. Other responses of the hybrids included an increase in lignin content, a decrease in relative proportions of d-glucose, and an increase in proportions of d-xylose. Differential responses between the hybrids were found in the syringyl:guaiacyl ratio in lignin. Conclusions In susceptible ‘Groeneveld’ plants, syringyl-rich lignin provided a far greater degree of protection from cellulose degradation than in ‘Dodoens’, but

  17. The pathogen causing Dutch elm disease makes host trees attract insect vectors

    PubMed Central

    McLeod, Geoff; Gries, Regine; von Reuß, Stephan H; Rahe, James E; McIntosh, Rory; König, Wilfried A; Gries, Gerhard

    2005-01-01

    Dutch elm disease is caused by the fungal pathogen Ophiostoma novo-ulmi which is transmitted by the native elm bark beetle, Hylurgopinus rufipes. We have found that four semiochemicals (the monoterpene (−)-β-pinene and the sesquiterpenes (−)-α-cubebene, (+)-spiroaxa-5,7-diene and (+)-δ-cadinene) from diseased American elms, Ulmus americana, synergistically attract H. rufipes, and that sesquiterpene emission is upregulated in elm trees inoculated with O. novo-ulmi. The fungus thus manipulates host trees to enhance their apparency to foraging beetles, a strategy that increases the probability of transportation of the pathogen to new hosts. PMID:16271975

  18. Simultaneous induction of jasmonic acid and disease-responsive genes signifies tolerance of American elm to Dutch elm disease

    PubMed Central

    Sherif , S. M.; Shukla, M. R.; Murch, S. J.; Bernier, L.; Saxena, P. K.

    2016-01-01

    Dutch elm disease (DED), caused by three fungal species in the genus Ophiostoma, is the most devastating disease of both native European and North American elm trees. Although many tolerant cultivars have been identified and released, the tolerance mechanisms are not well understood and true resistance has not yet been achieved. Here we show that the expression of disease-responsive genes in reactions leading to tolerance or susceptibility is significantly differentiated within the first 144 hours post-inoculation (hpi). Analysis of the levels of endogenous plant defense molecules such as jasmonic acid (JA) and salicylic acid (SA) in tolerant and susceptible American elm saplings suggested SA and methyl-jasmonate as potential defense response elicitors, which was further confirmed by field observations. However, the tolerant phenotype can be best characterized by a concurrent induction of JA and disease-responsive genes at 96 hpi. Molecular investigations indicated that the expression of fungal genes (i.e. cerato ulmin) was also modulated by endogenous SA and JA and this response was unique among aggressive and non-aggressive fungal strains. The present study not only provides better understanding of tolerance mechanisms to DED, but also represents a first, verified template for examining simultaneous transcriptomic changes during American elm-fungus interactions. PMID:26902398

  19. Simultaneous induction of jasmonic acid and disease-responsive genes signifies tolerance of American elm to Dutch elm disease.

    PubMed

    Sherif, S M; Shukla, M R; Murch, S J; Bernier, L; Saxena, P K

    2016-02-23

    Dutch elm disease (DED), caused by three fungal species in the genus Ophiostoma, is the most devastating disease of both native European and North American elm trees. Although many tolerant cultivars have been identified and released, the tolerance mechanisms are not well understood and true resistance has not yet been achieved. Here we show that the expression of disease-responsive genes in reactions leading to tolerance or susceptibility is significantly differentiated within the first 144 hours post-inoculation (hpi). Analysis of the levels of endogenous plant defense molecules such as jasmonic acid (JA) and salicylic acid (SA) in tolerant and susceptible American elm saplings suggested SA and methyl-jasmonate as potential defense response elicitors, which was further confirmed by field observations. However, the tolerant phenotype can be best characterized by a concurrent induction of JA and disease-responsive genes at 96 hpi. Molecular investigations indicated that the expression of fungal genes (i.e. cerato ulmin) was also modulated by endogenous SA and JA and this response was unique among aggressive and non-aggressive fungal strains. The present study not only provides better understanding of tolerance mechanisms to DED, but also represents a first, verified template for examining simultaneous transcriptomic changes during American elm-fungus interactions.

  20. Investigations of remote sensing techniques for early detection of Dutch elm disease

    NASA Technical Reports Server (NTRS)

    Hammerschlag, R. S.; Sopstyle, W. J.

    1975-01-01

    Several forms of aerial photography were pursued in quest of a technique which could provide early detection of Dutch elm disease. The two most promising techniques tested were multispectral photography with object enhancement and biband ratioing coupled with scanning microdensitometry. For practical purposes the multispectral system has the advantage of providing a readily interpretable image in a relatively short time. Laboratory studies indicated that less emphasis should be placed on the use of a red filter or the near infrared beyond 750 mm for early detection of stress within a single plant species. Color infrared film would be optimal when used for a long term detection of loss of plant vigor which results in a physical change in a plant canopy, but should find minimal practicality for early detection of specific sources of plant stress such as Dutch elm disease. Considerable discretion should be used when interpreting imagery on copy film because of loss of resolution and color definition.

  1. Bird mortality after spraying for Dutch elm disease with DDT

    USGS Publications Warehouse

    Wurster, C.F.; Wurster, D.H.; Strickland, W.N.

    1965-01-01

    In Hanover, New Hampshire, where elms were sprayed with DDT, 151 dead birds were found; 10 dead birds were found in Norwich, Vermont, where no DDT was used. Chemical analyses of dead birds, observation of symptoms of DDT poisoning, and a population decline after spraying all indicate severe mortality among certain species in Hanover.

  2. Time and materials needed to survey, inject systemic fungicides, and install root-graft barriers for Dutch elm disease management

    Treesearch

    William N., Jr. Cannon; Jack H. Barger; Charles J. Kostichka; Charles J. Kostichka

    1986-01-01

    Dutch elm disease control practice in 15 communities showed a wide range of time and material required to apply control methods. The median time used for each method was: sanitation survey, 9.8 hours per square mile; symptom survey, 96 hours per thousand elms; systemic fungicide injection, 1.4 hours per elm; and root-graft barrier installation, 2.2 hours per barrier (5...

  3. The Glenwood Estate: our 32-year experience using Arbotext® 20-S to control Dutch elm disease

    Treesearch

    William L. MacDonald; Mark L. Double; Cameron M. Stauder; Kemp. Winfree

    2017-01-01

    We report a case study that demonstrates the successful use of the fungicide Arbotect® 20-S to protect American elms (Ulmus americana) from Dutch elm disease at a historic site in Charleston, WV. Standard injection protocols were used every 3 to 4 years to deliver the chemical into the root flares. Twelve of the original 16 trees remain 34 years...

  4. Challenge inoculations to test for Dutch elm disease tolerance: a summary of methods used by various researchers

    Treesearch

    Linda M. Haugen; Garrett L. Beier; Susan E. Bentz; Raymond P. Guries; James M. Slavicek

    2017-01-01

    A variety of methods have been used by different research groups to "challenge" inoculate American elms (Ulmus americana) with the purpose of determining whether some clones may be resistant to the Dutch elm disease fungus. The methods used by seven research groups are described, along with observations on complications and benefits...

  5. Dutch elm disease: an overview of the biology and management regimens

    Treesearch

    R. Jay. Stipes

    2017-01-01

    Much of the information on the Dutch elm disease (DED) topic was generated by a large group of dedicated scientists, in several different agencies, primarily in the United States and Europe, over the last century. My work on the fungicidal management is but a modest contribution to the whole. It goes without saying that much more work needs to be done to open up new...

  6. Effects on wildlife of DDT used for control of Dutch elm disease

    USGS Publications Warehouse

    Benton, A.H.

    1951-01-01

    During the summer of 1949 studies were conducted at Princeton, New Jersey, to determine the effects on wildlife of DDT used in the control of Dutch elm disease. Direct mortality was determined by intensive search for dead birds after spraying. Twenty-six songbirds, one bat, and one gray squirrel were found. Of 11 dead birds from a study area of approximately 20 acres only one was an adult. Songbird populations were determined by censuses before and after spraying on a study area and on a similar unsprayed check area. The number of all breeding birds showed a 19.6 percent decrease on both the study and check areas during the week immediately following spraying. About two weeks after spraying the population in the treated area began to increase and within another week was back to prespray level. When only those species common to both sprayed and unsprayed areas are considered a population decline of 22 percent was measured in the sprayed area while the check area showed a 6 percent increase in numbers over the same period. Nestling mortality was studied in both areas. Among 18 young found on the study area during and following spraying 8 (44%) survived. Death of two broods of catbirds occurred four days after spraying. Of 21 young found on the check area 15 (71%) survived.

  7. Three American tragedies: chestnut blight, butternut canker, and Dutch elm disease

    Treesearch

    Scott E. Schlarbaum; Frederick Hebard; Pauline C. Spaine; Joseph C. Kamalay

    1998-01-01

    Three North American tree species, American chestnut (Castanea dentata), butternut (Juglans cinerea), and American elm (Ulmus americana), have been devastated by exotic fungal diseases over the last century. American chestnut was eliminated from eastern forests as a dominant species by chestnut blight (...

  8. Learning from history, predicting the future: the UK Dutch elm disease outbreak in relation to contemporary tree disease threats

    PubMed Central

    Potter, Clive; Harwood, Tom; Knight, Jon; Tomlinson, Isobel

    2011-01-01

    Expanding international trade and increased transportation are heavily implicated in the growing threat posed by invasive pathogens to biodiversity and landscapes. With trees and woodland in the UK now facing threats from a number of disease systems, this paper looks to historical experience with the Dutch elm disease (DED) epidemic of the 1970s to see what can be learned about an outbreak and attempts to prevent, manage and control it. The paper draws on an interdisciplinary investigation into the history, biology and policy of the epidemic. It presents a reconstruction based on a spatial modelling exercise underpinned by archival research and interviews with individuals involved in the attempted management of the epidemic at the time. The paper explores what, if anything, might have been done to contain the outbreak and discusses the wider lessons for plant protection. Reading across to present-day biosecurity concerns, the paper looks at the current outbreak of ramorum blight in the UK and presents an analysis of the unfolding epidemiology and policy of this more recent, and potentially very serious, disease outbreak. The paper concludes by reflecting on the continuing contemporary relevance of the DED experience at an important juncture in the evolution of plant protection policy. PMID:21624917

  9. Control of yeast-mycelium dimorphism in vitro in Dutch elm disease fungi by manipulation of specific external stimuli.

    PubMed

    Naruzawa, Erika Sayuri; Bernier, Louis

    2014-11-01

    Dutch elm disease (DED) fungi exhibit yeast-mycelium dimorphism both in planta and in vitro. However, previously published data on the transition between these two growth forms in vitro were mostly obtained from a single strain. We examined the effect of six factors on yeast-mycelium dimorphism in vitro in ten strains of Ophiostoma ulmi, Ophiostoma novo-ulmi and Ophiostoma himal-ulmi. Nitrogen sources, calcium, and yeast extract, altogether with inhibitors of phosphodiesterase (caffeine) and dioxygenases (propyl gallate and salicylic acid) were tested in defined culture media. Morphological response to manipulation of several of these factors varied according to the strain of Ophiostoma being analysed. Responses ranged from no statistical differences in morphological transitions to stimulation or reversion of yeast-mycelium dimorphism with the treatments that were tested. These results suggest that different mechanisms and pathways operate in the control of the yeast-mycelium transition in DED pathogens. Oxylipins could be involved in the yeast-to-mycelium transition, since the addition of a dioxygenase inhibitor, salicylic acid, reduced mycelium production in all strains that were tested.

  10. Can vessel dimension explain tolerance toward fungal vascular wilt diseases in woody plants? Lessons from Dutch elm disease and esca disease in grapevine.

    PubMed

    Pouzoulet, Jérôme; Pivovaroff, Alexandria L; Santiago, Louis S; Rolshausen, Philippe E

    2014-01-01

    This review illuminates key findings in our understanding of grapevine xylem resistance to fungal vascular wilt diseases. Grapevine (Vitis spp.) vascular diseases such as esca, botryosphaeria dieback, and eutypa dieback, are caused by a set of taxonomically unrelated ascomycete fungi. Fungal colonization of the vascular system leads to a decline of the plant host because of a loss of the xylem function and subsequent decrease in hydraulic conductivity. Fungal vascular pathogens use different colonization strategies to invade and kill their host. Vitis vinifera cultivars display different levels of tolerance toward vascular diseases caused by fungi, but the plant defense mechanisms underlying those observations have not been completely elucidated. In this review, we establish a parallel between two vascular diseases, grapevine esca disease and Dutch elm disease, and argue that the former should be viewed as a vascular wilt disease. Plant genotypes exhibit differences in xylem morphology and resistance to fungal pathogens causing vascular wilt diseases. We provide evidence that the susceptibility of three commercial V. vinifera cultivars to esca disease is correlated to large vessel diameter. Additionally, we explore how xylem morphological traits related to water transport are influenced by abiotic factors, and how these might impact host tolerance of vascular wilt fungi. Finally, we explore the utility of this concept for predicting which V. vinifera cultivars are most vulnerable of fungal vascular wilt diseases and propose new strategies for disease management.

  11. Can vessel dimension explain tolerance toward fungal vascular wilt diseases in woody plants? Lessons from Dutch elm disease and esca disease in grapevine

    PubMed Central

    Pouzoulet, Jérôme; Pivovaroff, Alexandria L.; Santiago, Louis S.; Rolshausen, Philippe E.

    2014-01-01

    This review illuminates key findings in our understanding of grapevine xylem resistance to fungal vascular wilt diseases. Grapevine (Vitis spp.) vascular diseases such as esca, botryosphaeria dieback, and eutypa dieback, are caused by a set of taxonomically unrelated ascomycete fungi. Fungal colonization of the vascular system leads to a decline of the plant host because of a loss of the xylem function and subsequent decrease in hydraulic conductivity. Fungal vascular pathogens use different colonization strategies to invade and kill their host. Vitis vinifera cultivars display different levels of tolerance toward vascular diseases caused by fungi, but the plant defense mechanisms underlying those observations have not been completely elucidated. In this review, we establish a parallel between two vascular diseases, grapevine esca disease and Dutch elm disease, and argue that the former should be viewed as a vascular wilt disease. Plant genotypes exhibit differences in xylem morphology and resistance to fungal pathogens causing vascular wilt diseases. We provide evidence that the susceptibility of three commercial V. vinifera cultivars to esca disease is correlated to large vessel diameter. Additionally, we explore how xylem morphological traits related to water transport are influenced by abiotic factors, and how these might impact host tolerance of vascular wilt fungi. Finally, we explore the utility of this concept for predicting which V. vinifera cultivars are most vulnerable of fungal vascular wilt diseases and propose new strategies for disease management. PMID:24971084

  12. Massive sequencing of Ulmus minor's transcriptome provides new molecular tools for a genus under the constant threat of Dutch elm disease.

    PubMed

    Perdiguero, Pedro; Venturas, Martin; Cervera, María Teresa; Gil, Luis; Collada, Carmen

    2015-01-01

    Elms, especially Ulmus minor and U. americana, are carrying out a hard battle against Dutch elm disease (DED). This vascular wilt disease, caused by Ophiostoma ulmi and O. novo-ulmi, appeared in the twentieth century and killed millions of elms across North America and Europe. Elm breeding and conservation programmes have identified a reduced number of DED tolerant genotypes. In this study, three U. minor genotypes with contrasted levels of tolerance to DED were exposed to several biotic and abiotic stresses in order to (i) obtain a de novo assembled transcriptome of U. minor using 454 pyrosequencing, (ii) perform a functional annotation of the assembled transcriptome, (iii) identify genes potentially involved in the molecular response to environmental stress, and (iv) develop gene-based markers to support breeding programmes. A total of 58,429 putative unigenes were identified after assembly and filtering of the transcriptome. 32,152 of these unigenes showed homology with proteins identified in the genome from the most common plant model species. Well-known family proteins and transcription factors involved in abiotic, biotic or both stresses were identified after functional annotation. A total of 30,693 polymorphisms were identified in 7,125 isotigs, a large number of them corresponding to single nucleotide polymorphisms (SNPs; 27,359). In a subset randomly selected for validation, 87% of the SNPs were confirmed. The material generated may be valuable for future Ulmus gene expression, population genomics and association genetics studies, especially taking into account the scarce molecular information available for this genus and the great impact that DED has on elm populations.

  13. Massive sequencing of Ulmus minor’s transcriptome provides new molecular tools for a genus under the constant threat of Dutch elm disease

    PubMed Central

    Perdiguero, Pedro; Venturas, Martin; Cervera, María Teresa; Gil, Luis; Collada, Carmen

    2015-01-01

    Elms, especially Ulmus minor and U. americana, are carrying out a hard battle against Dutch elm disease (DED). This vascular wilt disease, caused by Ophiostoma ulmi and O. novo-ulmi, appeared in the twentieth century and killed millions of elms across North America and Europe. Elm breeding and conservation programmes have identified a reduced number of DED tolerant genotypes. In this study, three U. minor genotypes with contrasted levels of tolerance to DED were exposed to several biotic and abiotic stresses in order to (i) obtain a de novo assembled transcriptome of U. minor using 454 pyrosequencing, (ii) perform a functional annotation of the assembled transcriptome, (iii) identify genes potentially involved in the molecular response to environmental stress, and (iv) develop gene-based markers to support breeding programmes. A total of 58,429 putative unigenes were identified after assembly and filtering of the transcriptome. 32,152 of these unigenes showed homology with proteins identified in the genome from the most common plant model species. Well-known family proteins and transcription factors involved in abiotic, biotic or both stresses were identified after functional annotation. A total of 30,693 polymorphisms were identified in 7,125 isotigs, a large number of them corresponding to single nucleotide polymorphisms (SNPs; 27,359). In a subset randomly selected for validation, 87% of the SNPs were confirmed. The material generated may be valuable for future Ulmus gene expression, population genomics and association genetics studies, especially taking into account the scarce molecular information available for this genus and the great impact that DED has on elm populations. PMID:26257751

  14. Functional Annotation of the Ophiostoma novo-ulmi Genome: Insights into the Phytopathogenicity of the Fungal Agent of Dutch Elm Disease

    PubMed Central

    Comeau, André M.; Dufour, Josée; Bouvet, Guillaume F.; Jacobi, Volker; Nigg, Martha; Henrissat, Bernard; Laroche, Jérôme; Levesque, Roger C.; Bernier, Louis

    2015-01-01

    The ascomycete fungus Ophiostoma novo-ulmi is responsible for the pandemic of Dutch elm disease that has been ravaging Europe and North America for 50 years. We proceeded to annotate the genome of the O. novo-ulmi strain H327 that was sequenced in 2012. The 31.784-Mb nuclear genome (50.1% GC) is organized into 8 chromosomes containing a total of 8,640 protein-coding genes that we validated with RNA sequencing analysis. Approximately 53% of these genes have their closest match to Grosmannia clavigera kw1407, followed by 36% in other close Sordariomycetes, 5% in other Pezizomycotina, and surprisingly few (5%) orphans. A relatively small portion (∼3.4%) of the genome is occupied by repeat sequences; however, the mechanism of repeat-induced point mutation appears active in this genome. Approximately 76% of the proteins could be assigned functions using Gene Ontology analysis; we identified 311 carbohydrate-active enzymes, 48 cytochrome P450s, and 1,731 proteins potentially involved in pathogen–host interaction, along with 7 clusters of fungal secondary metabolites. Complementary mating-type locus sequencing, mating tests, and culturing in the presence of elm terpenes were conducted. Our analysis identified a specific genetic arsenal impacting the sexual and vegetative growth, phytopathogenicity, and signaling/plant–defense–degradation relationship between O. novo-ulmi and its elm host and insect vectors. PMID:25539722

  15. RNAseq Analysis Highlights Specific Transcriptome Signatures of Yeast and Mycelial Growth Phases in the Dutch Elm Disease Fungus Ophiostoma novo-ulmi.

    PubMed

    Nigg, Martha; Laroche, Jérôme; Landry, Christian R; Bernier, Louis

    2015-09-17

    Fungal dimorphism is a complex trait and our understanding of the ability of fungi to display different growth morphologies is limited to a small number of model species. Here we study a highly aggressive dimorphic fungus, the ascomycete Ophiostoma novo-ulmi, which is a model in plant pathology and the causal agent of Dutch elm disease. The two growth phases that this fungus displays, i.e., a yeast phase and mycelial phase, are thought to be involved in key steps of disease development. We used RNAseq to investigate the genome-wide gene expression profiles that are associated with yeast and mycelial growth phases in vitro. Our results show a clear molecular distinction between yeast and mycelial phase gene expression profiles. Almost 12% of the gene content is differentially expressed between the two phases, which reveals specific functions related to each growth phase. We compared O. novo-ulmi transcriptome profiles with those of two model dimorphic fungi, Candida albicans and Histoplasma capsulatum. Few orthologs showed similar expression regulation between the two growth phases, which suggests that, globally, the genes associated with these two life forms are poorly conserved. This poor conservation underscores the importance of developing specific tools for emerging model species that are distantly related to the classical ones. Taken together, our results provide insights into transcriptome regulation and molecular specificity in O. novo-ulmi and offer a new perspective for understanding fungal dimorphism. Copyright © 2015 Nigg et al.

  16. Report from the street: elm reintroduction

    Treesearch

    Tom. Zetterstrom

    2017-01-01

    Since the introduction of Dutch elm disease (DED) to North America, heritage elm preservation was paramount, but elm restoration is held as the long-term solution. Various elm restoration efforts have been advanced and encouraged over the past half century, and all have inspired the euphoria of the "Return of the American Elm." The changing cast of characters...

  17. Hybridization and introgression patterns between native red elm (Ulmus rubra Muhl.) and exotic, invasive Siberian elm (Ulmus pumila L.) examined using species-specific microsatellite markers

    USDA-ARS?s Scientific Manuscript database

    Ulmus pumila (Siberian elm) is an invasive elm species, non-native to the United States, which hybridizes with Ulmus rubra (red elm), a U.S. native. While Siberian elm is highly tolerant to Dutch elm disease (DED), red elm populations in North America have been decimated by DED. In order to study ...

  18. Field response of the dutch elm disease vectors,Scolytus multistriatus (Marsham) andS. scolytus (F.) (Coleoptera: Scolytidae) to 4-methyl-3-heptanol baits containing α-, β-,δ-, or δ-multistriatin.

    PubMed

    Blight, M M; Fielding, N J; King, C J; Ottridge, A P; Wadhams, L J; Wenham, M J

    1983-01-01

    The field responses of English populations of the Dutch elm disease vectors,Scolytus multistriatus andS. scolytus to baits containing 4-methyl-3-heptanol, a host synergist [(-)-α-cubebene or (-)-limonene] and (±)-α-, (+)-β-, (-)-β-, (±)-γ-, or (±)-δ-multistriatin were examined. (±)-α-Multistriatin, released at 5-10 μg/day, enhanced the response ofS. multistriatus to baits containing 4-methyl-3-heptanol and either of the host synergists but had no effect on the capture ofS. scolytus. The release of larger amounts (57 or 365 μg/day) of (±)-α-multistriatin interrupted the response of both species to the 4-methyl-3-heptanol baits. It appears that α-multistriatin has multiple functions as a behavior-modifying substance for the two beetles. The (+)-β-, (-)-β-, (±)-γ-, and (±)-δ-multistriatins were inactive when released at 5-10 μg/day. The results of these field experiments suggest that one bait can be formulated to capture both species.

  19. Response of smaller European elm bark beetles to pruning wounds on American elm

    Treesearch

    Jack H. Barger; William N. Cannon

    1987-01-01

    From 1982 to 1984, inflight smaller European elm bark beetles, Scolytus multistriatus, were captured on American elms, Ulmus americana, that were therapeutically pruned for Dutch elm disease control. Pruning wounds were treated with wound dressing or left untreated to determine effects of the treatments on beetle attraction....

  20. Establishment and characterization of American elm cell suspension cultures

    Treesearch

    Steven M. Eshita; Joseph C. Kamalay; Vicki M. Gingas; Daniel A. Yaussy

    2000-01-01

    Cell suspension cultures of Dutch elm disease (DED)-tolerant and DED-susceptible American elms clones have been established and characterized as prerequisites for contrasts of cellular responses to pathogen-derived elicitors. Characteristics of cultured elm cell growth were monitored by A700 and media conductivity. Combined cell growth data for all experiments within a...

  1. Hybridization and introgression between the exotic Siberian elm, Ulmus pumila, and the native Field elm, U. minor, in Italy

    USDA-ARS?s Scientific Manuscript database

    In response to the first Dutch elm disease (DED) pandemic, Siberian elm, Ulmus pumila, was planted to replace the native elm, U. minor, in Italy. The potential for hybridization between these two species is high and repeated hybridization could result in the genetic swamping of the native species an...

  2. Ten-year performance of the United States national elm trial

    Treesearch

    Jason J. Griffin; William R. Jacobi; E. Gregory McPherson; Clifford S. Sadof; James R. McKenna; Mark L. Gleason; Nicole Ward Gauthier; Daniel A. Potter; David R. Smitley; Gerard C. Adams; Ann Brooks Gould; Christian R. Cash; James A. Walla; Mark C. Starrett; Gary Chastagner; Jeff L. Sibley; Vera A. Krischik; Adam F. Newby

    2017-01-01

    Ulmus americana (American elm) was an important urban tree in North America prior to the introduction of the Dutch elm disease pathogen in 1930. Subsequently, urban and community forests were devastated by the loss of large canopies. Tree improvement programs produced disease tolerant American and Eurasian elm cultivars and introduced them into the...

  3. Long-term impact of Ophiostoma novo-ulmi on leaf traits and transpiration of branches in the Dutch elm hybrid ‘Dodoens’

    PubMed Central

    Plichta, Roman; Urban, Josef; Gebauer, Roman; Dvořák, Miloň; Ďurkovič, Jaroslav

    2016-01-01

    To better understand the long-term impact of Ophiostoma novo-ulmi Brasier on leaf physiology in ‘Dodoens’, a Dutch elm disease-tolerant hybrid, measurements of leaf area, leaf dry mass, petiole anatomy, petiole hydraulic conductivity, leaf and branch water potential, and branch sap flow were performed 3 years following an initial artificial inoculation. Although fungal hyphae were detected in fully expanded leaves, neither anatomical nor morphological traits were affected, indicating that there was no impact from the fungal hyphae on the leaves during leaf expansion. In contrast, however, infected trees showed both a lower transpiration rate of branches and a lower sap flow density. The long-term persistence of fungal hyphae inside vessels decreased the xylem hydraulic conductivity, but stomatal regulation of transpiration appeared to be unaffected as the leaf water potential in both infected and non-infected trees was similarly driven by the transpirational demands. Regardless of the fungal infection, leaves with a higher leaf mass per area ratio tended to have a higher leaf area-specific conductivity. Smaller leaves had an increased number of conduits with smaller diameters and thicker cell walls. Such a pattern could increase tolerance towards hydraulic dysfunction. Measurements of water potential and theoretical xylem conductivity revealed that petiole anatomy could predict the maximal transpiration rate. Three years following fungal inoculation, phenotypic expressions for the majority of the examined traits revealed a constitutive nature for their possible role in Dutch elm disease tolerance of ‘Dodoens’ trees. PMID:26843210

  4. Long-term impact of Ophiostoma novo-ulmi on leaf traits and transpiration of branches in the Dutch elm hybrid 'Dodoens'.

    PubMed

    Plichta, Roman; Urban, Josef; Gebauer, Roman; Dvořák, Miloň; Ďurkovič, Jaroslav

    2016-03-01

    To better understand the long-term impact of Ophiostoma novo-ulmi Brasier on leaf physiology in 'Dodoens', a Dutch elm disease-tolerant hybrid, measurements of leaf area, leaf dry mass, petiole anatomy, petiole hydraulic conductivity, leaf and branch water potential, and branch sap flow were performed 3 years following an initial artificial inoculation. Although fungal hyphae were detected in fully expanded leaves, neither anatomical nor morphological traits were affected, indicating that there was no impact from the fungal hyphae on the leaves during leaf expansion. In contrast, however, infected trees showed both a lower transpiration rate of branches and a lower sap flow density. The long-term persistence of fungal hyphae inside vessels decreased the xylem hydraulic conductivity, but stomatal regulation of transpiration appeared to be unaffected as the leaf water potential in both infected and non-infected trees was similarly driven by the transpirational demands. Regardless of the fungal infection, leaves with a higher leaf mass per area ratio tended to have a higher leaf area-specific conductivity. Smaller leaves had an increased number of conduits with smaller diameters and thicker cell walls. Such a pattern could increase tolerance towards hydraulic dysfunction. Measurements of water potential and theoretical xylem conductivity revealed that petiole anatomy could predict the maximal transpiration rate. Three years following fungal inoculation, phenotypic expressions for the majority of the examined traits revealed a constitutive nature for their possible role in Dutch elm disease tolerance of 'Dodoens' trees.

  5. Development of methods for the restoration of the American elm in forested landscapes

    Treesearch

    James M. Slavicek

    2013-01-01

    A project was initiated in 2003 to establish test sites to develop methods to reintroduce the American elm (Ulmus americana L.) in forested landscapes. American elm tree strains with high levels of tolerance to Dutch elm disease (DED) were established in areas where the trees can naturally regenerate and spread. The process of regeneration will...

  6. The ecological role of American elm (Ulmus americana L.) in floodplain forests of northeastern North America

    Treesearch

    Christian O. Marks

    2017-01-01

    Before Dutch elm disease, the American elm (Ulmus americana L.) was a leading dominant tree species in the better drained parts of floodplain forests where flooding occurs about 1 percent of the time. Although still common in these habitats today, U. americana now rarely lives long enough to reach the forest canopy because elm...

  7. Genome size variation in elms (Ulmus spp.) and related genera

    USDA-ARS?s Scientific Manuscript database

    The elms (the genus Ulmus) are one of the most important tree crops for the $4.7-billion per year U.S. nursery industry. Utilization of these plants has been limited in recent decades by diseases introduced from the Old World, especially Dutch elm disease. Past research and breeding have been based ...

  8. Pruning cycles and storm damage: are young American elms failing prematurely?

    Treesearch

    Chad P. Giblin

    2017-01-01

    The use of Dutch elm disease-resistant elms as a common replacement tree in municipal planting schedules has amassed a large population of these trees in many cities throughout the eastern half of the United States. Reports from practitioners have suggested that this population is vulnerable to catastrophic losses due to severe canopy failures during wind-loading...

  9. Elm leaf beetle performance on ozone-fumigated elm. Forest Service research paper (Final)

    SciTech Connect

    Barger, J.H.; Hall, R.W.; Townsend, A.M.

    1992-01-01

    Leaves (1986) from elm hybrids ('Pioneer', 'Homestead', '970') previously fumigated in open-top chambers with ozone or with charcoal-filtered air (CFA) were evaluated for water and nitrogen content or were fed to adult elm leaf beetles (ELB), Xanthogaleruca = (Pyrrhalta) luteola (Muller), to determine host suitability for beetle fecundity and survivorship. ELB females fed ozone-fumigated leaves laid significantly fewer eggs than females fed CFA-fumigated leaves. Leaf nitrogen or water content was unaffected. Hybrid '970' (1988) was fumigated with CFA or with ozone concentrations to determine effects on ELB fecundity, leaf consumption, and survivorship. Significantly fewer eggs were laid at the higher concentration of ozone. Because higher levels of ozone are found in urban areas and because municipalities often replace American elms, Ulmus americana L., with Dutch elm disease-resistant elm hybrids that are susceptible to ELB defoliation, it is important to explore the relationships between ozone sensitivity of elm and susceptibility to ELB herbivory before recommending replacement use of these elms to municipal arborists. The study was conducted to determine whether ozone pollution influences host quality of elm for ELB and how ELB fecundity, leaf consumption rate, and survivorship are affected.

  10. Restoring ecosystem resilience to urban forests using Dutch elm disease-tolerant American elm trees

    Treesearch

    Charles E. Flower; Cornelia C. Pinchot; James M. Slavicek

    2017-01-01

    Urban forests contribute significantly to human health and environmental quality (Sanesi et al. 2011). As such, maintaining healthy urban forests resilient to pollution (atmospheric and soil), high temperatures, compacted soils, and poor drainage is critical. However, these forests have been hard hit by development, pests, and pathogens, consequently reshaping their...

  11. How contagious is Dutch disease

    SciTech Connect

    Laney, L.O.

    1982-03-01

    Into the vernacular of economists has come the term Dutch Disease from the Netherland's experience as a net energy exporter. After outlining characterisics of the affliction and the ways in which it can be manifested, this article looks at the economies of United Kingdom, Norway, and Mexico. While the stage of economic development, the structure of the balance of payments, and the exchange-rate regime are at least somewhat different for each, all have economies that are feeling the impact of the energy sector. Common factors are a higher value for the exchange rate than would otherwise be the case and a squeeze on nonenergy sectors of the economy. 4 figures.

  12. Use of culture filtrates of Ceratocystis ulmi as a bioassay to screen for disease tolerant Ulmus americana

    Treesearch

    Paula M. Pijut; Subash C. Domir; R. Daniel Lineberger; Lawrence R. Schreiber

    1990-01-01

    Callus cultures of elm (Ulmus americana L.) derived from Dutch elm disease susceptible, intermediate-resistant, and resistant genotypes were exposed to the culture filtrates of three pathogenic isolates of Ceratocystis ulmi, the causal agent of Dutch elm disease. Callus fresh weights, cell viability, and reactions of stem cuttings...

  13. Canopy decline assessment in American elm after inoculation with different doses of Ophiostoma ulmi and O. novo-ulmi

    Treesearch

    Charles E. Flower; James M. Slavicek; Dale Lesser; Steven Eshita; Cornelia C. Pinchot

    2017-01-01

    Restoration of American elm (Ulmus americana L.) in natural and urban landscapes necessitates the development of new selections that not only exhibit Dutch elm disease (DED, caused by the fungal pathogen Ophiostoma novo-ulmi and O. ulmi) tolerance, but also an increase the genetic variability of tolerant...

  14. Trap trees for elm bark beetles : Augmentation with pheromone baits and chlorpyrifos.

    PubMed

    Lanier, G N; Jones, A H

    1985-01-01

    European elm bark beetles,Scolytus multistriatus (Marsh.), were strongly attracted to American elms,Ulmus americana L., baited with theS. multistriatus attractant, multilure, or killed by injection of the arboricide, cacodylic acid; a combination of the two treatments was most attractive. Comparisons of beetle catches on sticky bands affixed to the trees with samples of bark from the same trees showed that the number of beetles landing on cacodylic acid-treated trees was approximately 40 times greater than the number boring into them. Spraying the bark with the insecticide chlorpyrifos had no direct effect on attraction. No live bark beetle brood was found in trees that had been treated with cacodylic acid or chlorpyrifos, but trees that were only baited or left untreated (check) were attacked, killed, and colonized. We suggest that the contribution of the cacodylic acid trap tree technique to Dutch elm disease control will be enhanced by baiting treated trees with multilure and spraying their lower boles with 0.5% chlorpyrifos. This treatment will eliminate diseased and unwanted elms as potential breeding material and kill large numbers of elm bark beetles that might otherwise innoculate healthy elms with the Dutch elm disease fungus.

  15. Components of moribund American elm trees as attractants to elm bark beetles,Hylurgopinus rufipes and Scolytus multistriatus.

    PubMed

    Millar, J G; Zhao, C H; Lanier, G N; O'Callaghan, D P; Griggs, M; West, J R; Silverstein, R M

    1986-03-01

    Hylurgopinus rufipes male and female beetles were attracted to American elms infected with Dutch elm disease, and to American elms killed by injection of cacodylic acid.H. rufipes was also attracted to solvent extracts of elm, or to Porapak Q-trapped volatiles from elm. The major components of attractive fractions of Porapak Q-trapped volatiles were isolated, identified, and tested in field bioassays. Several artificially compounded mixtures of sesquiterpenes were attractive toH. rufipes, although no bait tested was as attractive as diseased tree controls. Laboratory bioassays with H. rufipes were marginally successful. In laboratory bioassays, nine of 14 sequiterpenes identified from active fractions of Porapak extracts elicited significant response from Scolytus multistriatus male and female beetles: δ- and γ-cadinene, α-cubebene, γ-muurolene, and β-elemene were most active. However, in field tests, none of the sesquiterpenes alone or in combination significantly attracted S. multistriatus, nor did they significantly enhance the attraction of S. multistriatus to female-produced pheromone components (4-methyl-3-heptanol [H] and α-multistriatin [M]). In other field tests, α-cubebene (C) significantly enhanced response of S. multistriatus to H plus M, but foliage, logs, or chips of healthy elm did not enhance trap catch to HMC.

  16. Conservation of genetic diversity in slippery elm (Ulmus rubra) in Wisconsin despite the devastating impact of Dutch elm disease

    USDA-ARS?s Scientific Manuscript database

    Forest trees tend to be genetically diverse, a condition related to their longevity, outcrossing mating system and extensive gene flow that maintains high levels of genetic diversity within populations. Forest pest epidemics are responsible for many historic and contemporary population declines repo...

  17. PERKINELMER ELM

    EPA Science Inventory

    The PerkinElmer Elm (formerly the AirBase CanarIT) is a multi-sensor air quality monitoring device that measures particulate matter (PM), total volatile organic compounds (VOCs), nitrogen dioxide (NO2), and several other atmospheric components. PM, VOCs, and NO2

  18. PERKINELMER ELM

    EPA Science Inventory

    The PerkinElmer Elm (formerly the AirBase CanarIT) is a multi-sensor air quality monitoring device that measures particulate matter (PM), total volatile organic compounds (VOCs), nitrogen dioxide (NO2), and several other atmospheric components. PM, VOCs, and NO2

  19. Plant signals during beetle (Scolytus multistriatus) feeding in American elm (Ulmus americana Planch).

    PubMed

    Saremba, Brett M; Tymm, Fiona J M; Baethke, Kathy; Rheault, Mark R; Sherif, Sherif M; Saxena, Praveen K; Murch, Susan J

    2017-05-04

    American Elms were devastated by an outbreak of Dutch Elm Disease is caused by the fungus Ophiostoma novo-ulmi Brasier that originated in Asia and arrived in the early 1900s. In spite of decades of study, the specific mechanisms and disease resistance in some trees is not well understood. the fungus is spread by several species of bark beetles in the genus Scolytus, during their dispersal and feeding. Our objective was to understand elm responses to beetle feeding in the absence of the fungus to identify potential resistance mechanisms. A colony of Scolytus multistriatus was established from wild-caught beetles and beetles were co-incubated with susceptible or resistant American elm varieties in a controlled environment chamber. Beetles burrowed into the auxillary meristems of the young elm shoots. The trees responded to the beetle damage by a series of spikes in the concentration of plant growth regulating compounds, melatonin, serotonin, and jasmonic acid. Spikes in melatonin and serotonin represented a 7,000-fold increase over resting levels. Spikes in jasmonic acid were about 10-fold higher than resting levels with one very large spike observed. Differences were noted between susceptible and resistant elms that provide new understanding of plant defenses.

  20. Preventing the Dutch Disease: The case of Indonesia

    SciTech Connect

    Ramli, R.

    1992-01-01

    Indonesia has been more successful than other oil exporters in mitigating the effects of the Dutch Disease, the decline in non-oil production associated with an oil boom. Typically sharp increases in oil revenues promote the accumulation of international reserves, increasing monetization, and raising prices of non-traded relative to traded goods. The latter causes contraction of output and employment in the traded sector. This study analyzes the magnitude of the boom and its fiscal, monetary, and production effects. Proxies of the real exchange rate, defined as the relative price of traded to non-traded goods, were constructed. The effect of the exchange rate on the Dutch Disease problems were examined. The movement of the real exchange rate and the remarkable growth of production of traded goods indicate that the effects of the Dutch Disease on the Indonesian economy were remarkably limited. Structural and policy-induced factors, such as exchange rate protection and micro interventions, that mitigated the anticipated effects of the Dutch Disease are examined.

  1. Progress and issues in understanding the physics of ELM dynamics, ELM mitigation, and ELM control

    NASA Astrophysics Data System (ADS)

    Oyama, N.

    2008-07-01

    Recent experimental progress in understanding the dynamics of type I ELM, small/no ELM regimes to achieve ELM mitigation and active ELM controls is reviewed. As for the type I ELM dynamics, the smaller growth rate of the ELM precursor relative to the Alfvén frequency, the importance of ELM filaments to evaluate the ELM heat load, the evolution of pedestal pressure in the recovery phase, and the effects of edge toroidal rotation and toroidal field ripple on ELM energy loss have been observed in many devices. In low collisionality (ve*) small/no ELM regimes, the type V ELM has been obtained with one or two filaments in ve*<1 condition. Small normalized ELM energy loss less than 1% has been achieved in the grassy ELM regime in non-rotating plasmas. The highest pedestal pressure has been achieved with smaller edge toroidal rotation counter to the plasma current in the QH-mode. ELM control/suppression by pellet pacing and external magnetic field perturbation has been demonstrated, and so that a design activity of ELM control coils for ITER has started. Various effects of the edge toroidal rotation upon ELM characteristics have been found such as ELM energy loss (ELM frequency) in the type I ELM regime and the grassy ELM regime, changes in edge harmonic oscillation and achievable pedestal pressure in the QH-mode regime, and a screening effect in evaluation of island formation by ELM control coils.

  2. The nutritional status of Dutch elderly patients with Parkinson's disease.

    PubMed

    van Steijn, J; van Harten, B; Flapper, E; Droogsma, E; van Walderveen, P; Blaauw, M; van Asselt, D

    2014-01-01

    To assess the prevalence of (risk of) undernutrition in Dutch elder Parkinson's disease patients as well as it's risk factors. Observational cross-sectional study. An outpatient clinic at the department Neurology of Medical Centre Leeuwarden, a large teaching hospital. 102 outpatients with Parkinson's disease aged 65 years and older were recruited. Data regarding various aspects of undernutrition including socio-demographic aspect, disease characterisitics, nutritional status, appetite and overall-physical and psychological functioning were collected. Undernutrition was diagnosed in 2.0% and 20.5% of the patients were categorized as being at risk of undernutrition. Care dependency and appetite were the two risk factors with the highest predictive value for an unfavorable nutritional status. Of Dutch elderly patients with Parkinson's Disease 22.5% had an unfavourable nutritional status. Dependency and appetite were the two risk factors with the highest predictive value fort his outcome. Because undernutrition can be regarded as a geriatric syndrome a comprehensive nutritional assessment should be done followed by nutritional interventions next to interventions focused on the risk factors. Further studies are needed to evaluate these interventions.

  3. Ulmus crassifolia Nutt. Cedar Elm

    Treesearch

    John J. Stransky; Sylvia M. Bierschenk

    1990-01-01

    Cedar elm (Ulmus cassifolia) grows rapidly to medium or large size in the Southern United States and northeastern Mexico, where it may sometimes be called basket elm, red elm, southern rock elm, or olmo (Spanish) It usually is found on moist, limestone soils along water courses with other bottomland trees, but it also paws on dry limestone hills. The...

  4. Dutch Disease model of a natural resource export boom: coal in Columbia

    SciTech Connect

    Seidelman, J.E.

    1987-01-01

    This dissertation examines the economic adjustments of a natural resource export boom in a developing country using a Dutch Disease approach. It surveys the existing literature on general-equilibrium Dutch Disease models. In addition, intermediate goods are introduced, and the changes this brings in Dutch Disease adjustment of an export boom are explored. The Colombian coffee and drug booms of the 1970s are analyzed using a Dutch Disease framework. Econometric estimations of several key Dutch Disease variables are conducted. Furthermore, Colombia's policy response to the coffee and drug booms is examined as a means to identify appropriate policy responses for developing countries in the event of an export boom. This study explicitly integrates many of the socio-economic characteristics and policy problems peculiar to developing countries with Dutch Disease analysis of a boom. This integration is extended by examining how a booming export such as Cerrejon coal may affect factor incomes and sectoral allocations in Colombia. Finally, Colombia's policy options are explored given the introduction of Colombia's newest booming export (Cerrejon Coal), along with some concluding thoughts about Dutch Disease adjustment, natural resource export booms and developing countries.

  5. Inhibition of phenylpropanoid biosynthesis increases cell wall digestibility, protoplast isolation, and facilitates sustained cell division in American elm (Ulmus americana)

    PubMed Central

    2012-01-01

    Background Protoplast technologies offer unique opportunities for fundamental research and to develop novel germplasm through somatic hybridization, organelle transfer, protoclonal variation, and direct insertion of DNA. Applying protoplast technologies to develop Dutch elm disease resistant American elms (Ulmus americana L.) was proposed over 30 years ago, but has not been achieved. A primary factor restricting protoplast technology to American elm is the resistance of the cell walls to enzymatic degradation and a long lag phase prior to cell wall re-synthesis and cell division. Results This study suggests that resistance to enzymatic degradation in American elm was due to water soluble phenylpropanoids. Incubating tobacco (Nicotiana tabacum L.) leaf tissue, an easily digestible species, in aqueous elm extract inhibits cell wall digestion in a dose dependent manner. This can be mimicked by p-coumaric or ferulic acid, phenylpropanoids known to re-enforce cell walls. Culturing American elm tissue in the presence of 2-aminoindane-2-phosphonic acid (AIP; 10-150 μM), an inhibitor of phenylalanine ammonia lyase (PAL), reduced flavonoid content, decreased tissue browning, and increased isolation rates significantly from 11.8% (±3.27) in controls to 65.3% (±4.60). Protoplasts isolated from callus grown in 100 μM AIP developed cell walls by day 2, had a division rate of 28.5% (±3.59) by day 6, and proliferated into callus by day 14. Heterokaryons were successfully produced using electrofusion and fused protoplasts remained viable when embedded in agarose. Conclusions This study describes a novel approach of modifying phenylpropanoid biosynthesis to facilitate efficient protoplast isolation which has historically been problematic for American elm. This isolation system has facilitated recovery of viable protoplasts capable of rapid cell wall re-synthesis and sustained cell division to form callus. Further, isolated protoplasts survived electrofusion and viable

  6. VIEW OF ELM DRIVE FROM ITS INTERSECTION WITH ELM CIRCLE. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF ELM DRIVE FROM ITS INTERSECTION WITH ELM CIRCLE. VIEW FACING SOUTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  7. American elm (Ulmus americana) in restoration plantings: a review

    Treesearch

    Kathleen S. Knight; Linda M. Haugen; Cornelia C. Pinchot; Paul G. Schaberg; James M. Slavicek

    2017-01-01

    The development of disease-tolerant American elm (Ulmus americana) trees has led to a need for reintroduction and restoration methods for the species. Here we review the current state of experimental work to inform reintroduction biology and restoration ecology of American elm. Much of this work is ongoing, and within several years the results will...

  8. Elm leaf beetle performance on ozone-fumigated elm

    Treesearch

    Jack H. Barger; Richard W. Hall; Alden M. Townsend; Alden M. Townsend

    1992-01-01

    Leaves (1986) from elm hybrids ('Pioneer', 'Homestead', '970') previously fumigated in open-top chambers with ozone or with charcoal-filtered air (CFA) were evaluated for water and nitrogen content or were fed to adult elm leaf beetles (ELB), Xanthogaleruca = (Pyrrhallta) luteola (Muller), to determine host suitability for beetle fecundity...

  9. Temporal fluctuations and the role of disturbance in disease progression of the sudden oak death epidemic

    Treesearch

    Melina Kozanitas; Todd W. Osmundson; Matteo Garbelotto

    2013-01-01

    With its high host mortality and ability to cause landscape-scale alterations in forest cover and composition, sudden oak death (SOD) (etiological agent Phytophthora ramorum, Stramenopila, Oomycota) mirrors past forest disease epidemics such as Chestnut Blight and Dutch Elm Disease. In contrast with these past epidemics, however, the appearance of...

  10. Compliance of disease awareness campaigns in printed Dutch media with national and international regulatory guidelines.

    PubMed

    Leonardo Alves, Teresa; Martins de Freitas, Auramarina F; van Eijk, Martine E C; Mantel-Teeuwisse, Aukje K

    2014-01-01

    The European legislation prohibits prescription-only medicines' advertising but allows pharmaceutical companies to provide information to the public on health and diseases, provided there is no direct or indirect reference to a pharmaceutical product. Various forms of promotion have become increasingly common in Europe including "disease-oriented" campaigns. To explore examples of disease awareness campaigns by pharmaceutical companies in the Netherlands, by assessing their compliance with the World Health Organization (WHO) Ethical Criteria for medicinal drug promotion and the Dutch guidelines for provision of information by pharmaceutical companies. Materials referring to health/disease and treatments published in the most widely circulated newspapers and magazines were collected from March to May 2012. An evaluation tool was developed based on relevant underlying principles from the WHO ethical criteria and Dutch self-regulation guidelines. Collected disease awareness advertisements were used to pilot the evaluation tool and to explore the consistency of information provided with the WHO and Dutch criteria. Eighty materials met our inclusion criteria; 71 were published in newspapers and 9 in magazines. The large majority were news items but 21 were disease awareness advertisements, of which 5 were duplicates. Fifteen out of the 16 disease awareness campaigns were non-compliant with current guidelines mainly due to lack of balance (n = 12), absence of listed author and/or sponsor (n = 8), use of misleading or incomplete information (n = 5) and use of promotional information (n = 5). None mentioned a pharmaceutical product directly. Disease Awareness Campaigns are present in Dutch printed media. Although no brand names were mentioned, the lack of compliance of disease awareness campaigns with the current regulations is alarming. There were information deficiencies and evidence of information bias. A key concern is that the context in which the information is

  11. Compliance of Disease Awareness Campaigns in Printed Dutch Media with National and International Regulatory Guidelines

    PubMed Central

    Leonardo Alves, Teresa; Martins de Freitas, Auramarina F.; van Eijk, Martine E. C.; Mantel-Teeuwisse, Aukje K.

    2014-01-01

    Background The European legislation prohibits prescription-only medicines' advertising but allows pharmaceutical companies to provide information to the public on health and diseases, provided there is no direct or indirect reference to a pharmaceutical product. Various forms of promotion have become increasingly common in Europe including “disease-oriented” campaigns. Objectives To explore examples of disease awareness campaigns by pharmaceutical companies in the Netherlands, by assessing their compliance with the World Health Organization (WHO) Ethical Criteria for medicinal drug promotion and the Dutch guidelines for provision of information by pharmaceutical companies. Methods Materials referring to health/disease and treatments published in the most widely circulated newspapers and magazines were collected from March to May 2012. An evaluation tool was developed based on relevant underlying principles from the WHO ethical criteria and Dutch self-regulation guidelines. Collected disease awareness advertisements were used to pilot the evaluation tool and to explore the consistency of information provided with the WHO and Dutch criteria. Findings Eighty materials met our inclusion criteria; 71 were published in newspapers and 9 in magazines. The large majority were news items but 21 were disease awareness advertisements, of which 5 were duplicates. Fifteen out of the 16 disease awareness campaigns were non-compliant with current guidelines mainly due to lack of balance (n = 12), absence of listed author and/or sponsor (n = 8), use of misleading or incomplete information (n = 5) and use of promotional information (n = 5). None mentioned a pharmaceutical product directly. Conclusion Disease Awareness Campaigns are present in Dutch printed media. Although no brand names were mentioned, the lack of compliance of disease awareness campaigns with the current regulations is alarming. There were information deficiencies and evidence of information

  12. ELM frequency feedback control on JET

    NASA Astrophysics Data System (ADS)

    Lennholm, M.; Beaumont, P. S.; Carvalho, I. S.; Chapman, I. T.; Felton, R.; Frigione, D.; Garzotti, L.; Goodyear, A.; Graves, J.; Grist, D.; Jachmich, S.; Lang, P.; Lerche, E.; de la Luna, E.; Mooney, R.; Morris, J.; Nave, M. F. F.; Rimini, F.; Sips, G.; Solano, E.; Tsalas, M.; EFDA Contributors, JET

    2015-06-01

    This paper describes the first development and implementation of a closed loop edge localized mode (ELM) frequency controller using gas injection as the actuator. The controller has been extensively used in recent experiments on JET and it has proved to work well at ELM frequencies in the 15-40 Hz range. The controller responds effectively to a variety of disturbances, generally recovering the requested ELM frequency within approximately 500 ms. Controlling the ELM frequency has become of prime importance in the new JET configuration with all metal walls, where insufficient ELM frequency is associated with excessive tungsten influx. The controller has allowed successful operation near the minimum acceptable ELM frequency where the best plasma confinement can be achieved. Use of the ELM frequency controller in conjunction with pellet injection has enabled investigations of ELM triggering by pellets while maintaining the desired ELM frequency even when pellets fail to trigger ELMs.

  13. ELM Studies on DIII--D

    NASA Astrophysics Data System (ADS)

    Osborne, T. H.; Leonard, A. W.; Porter, G. D.

    1996-11-01

    Three classes of Edge Localized Modes, or ELMs, simply labeled Types I, II, and III, in the DIII--D work, are widely observed. Type I ELMs are distinguished by the fact that their frequency increases with increasing input power. A scaling for the Type I ELM energy loss predicts 3% for ITER. The frequency of Type III ELMs decreases with increasing input power. The energy loss per Type III ELM is a factor of 2 to 4 below that for Type I at the same input power. Experiments on DIII--D suggest that proximity to the H--mode threshold power is the critical parameter for Type III ELMs. In contrast to Type I ELMs, the pressure gradient near the separatrix at a Type III ELM is often well below the ideal ballooning mode limit. Medium n magnetic precursor oscillations are observed with Type III ELMs, while no magnetic precursors are observe with Type I ELMs. Type II ELMs have very high frequency and low energy loss compared to Type I ELMs. Type II ELMs do not require low input power in contrast to Type III ELMs. Type II ELMs are associated with edge second stability in combination with either high q or high β_P.

  14. Celiac Disease in The Netherlands: Demographic Data of Members of the Dutch Celiac Society.

    PubMed

    van Gils, Tom; Rootsaert, Bianca; Bouma, Gerd; Mulder, Chris J J

    2016-12-01

    Celiac disease is an autoimmune disease induced by the intake of gluten with a female to male ratio of 2-4:1. Female predominance has not been recognized in serological mass screening studies. Limited data are available on gender and age distribution in the daily clinical practice of celiac disease. The aim of this study is to describe differences in gender and age at the time of celiac disease diagnosis in the Netherlands. Data was obtained from a prospectively maintained database of members of the Dutch Celiac Society in whom celiac disease was diagnosed between 1980 and August 2015. retrospective database study; Setting: database of members of the Dutch Celiac Society; Participants: out of the total number of 26,986 current and ex-members, the data of 7,886 members could be used for analysis. Age at celiac disease diagnosis ranged between 0 and 88 years; the minority (36%) were diagnosed in childhood. In children, the majority (52%) were diagnosed before the age of 4 years. Median age did not differ in children when compared for gender (3 years). In adults, median age differed between males (52 years, IQR 41-61) and females (44 years, IQR 32-56), p<0.001. Female to male ratio was 2.4:1. The majority of celiac disease patients are diagnosed during adulthood, with males diagnosed at an older age. Only one-third of the patients were diagnosed at childhood. Celiac disease is less frequently diagnosed in young adult males.

  15. Proceedings of the American elm restoration workshop 2016

    Treesearch

    Cornelia C. Pinchot; Kathleen S. Knight; Linda M. Haugen; Charles E. Flower; James M. Slavicek

    2017-01-01

    Proceedings from the 2016 American Elm Restoration Workshop in Lewis Center, OH. The published proceedings include 16 papers pertaining to elm pathogens, American elm ecology, and American elm reintroduction.

  16. An annotated list of the cicadellidae and fulgoridae of elm

    Treesearch

    Lester P. Gibson

    1973-01-01

    This annotated list includes 87 cicadellid and 13 fulgorid entries that were found on and probably feed on elm to some extent. Thirteen of the cicadellid species listed are known vectors of virus or mycoplasmalike diseases of plants. Also, the following 18 cicadellid genera contain known vectors of virus or mycoplasmalike diseases of plants: Aceratagallia...

  17. Hereditary cerebral hemorrhage with amyloidosis in patients of Dutch origin is related to Alzheimer disease

    SciTech Connect

    van Duinen, S.G.; Castano, E.M.; Prelli, F.; Bots, G.T.A.B.; Luyendijk, W.; Frangione, B.

    1987-08-01

    Hereditary cerebral hemorrhage with amyloidosis in Dutch patients is an autosomal dominant form of vascular amyloidosis restricted to the leptomeninges and cerebral cortex. Clinically the disease is characterized by cerebral hemorrhages leading to an early death. Immunohistochemical studies of five patients revealed that the vascular amyloid deposits reacted intensely with an antiserum raised against a synthetic peptide homologous to the Alzheimer disease-related ..beta..-protein. Silver stain-positive, senile plaque-like structures were also labeled by the antiserum, yet these lesions lacked the dense amyloid cores present in typical plaques of Alzheimer disease. No neurofibrillary tangles were present. Amyloid fibrils were purified from the leptomeningeal vessels of one patient who clinically had no signs of dementia. The protein had a molecular weight of approx. 4000 and its partial amino acid sequence to position 21 showed homology to the ..beta..-protein of Alzheimer disease and Down syndrome. These results suggest that hereditary cerebral hemorrhage with amyloidosis of Dutch origin is pathogenetically related to Alzheimer disease and support the concept that the initial amyloid deposition in this disorder occurs in the vessel walls before damaging the brain parenchyma. Thus, deposition of ..beta..-protein in brain tissue seems to be related to a spectrum of diseases involving vascular syndromes, progressive dementia, or both.

  18. Peeling mode relaxation ELM model

    SciTech Connect

    Gimblett, C. G.

    2006-11-30

    This paper discusses an approach to modelling Edge Localised Modes (ELMs) in which toroidal peeling modes are envisaged to initiate a constrained relaxation of the tokamak outer region plasma. Relaxation produces both a flattened edge current profile (which tends to further destabilise a peeling mode), and a plasma-vacuum negative current sheet which has a counteracting stabilising influence; the balance that is struck between these two effects determines the radial extent (rE) of the ELM relaxed region. The model is sensitive to the precise position of the mode rational surfaces to the plasma surface and hence there is a 'deterministic scatter' in the results that has an accord with experimental data. The toroidal peeling stability criterion involves the edge pressure, and using this in conjunction with predictions of rE allows us to evaluate the ELM energy losses and compare with experiment. Predictions of trends with the edge safety factor and collisionality are also made.

  19. The Dutch functional performance inventory: validity and reliability in patients with chronic obstructive lung disease.

    PubMed

    Weldam, Saskia W M; Lammers, Jan-Willem J; de Bruin-Veelers, M C Caroline; Schuurmans, Marieke J

    2015-01-01

    Performing activities of daily living (ADLs) is an important outcome measure in chronic obstructive pulmonary disease (COPD). The functional performance inventory (FPI) can be used to measure ADL performance in people with COPD. The aims are to report translation of the FPI into the Dutch language and evaluate the validity and reliability of the translated version in a Dutch COPD population. The FPI was translated, after which validation and test-retest reliability studies were conducted. The Consensus-Based Standards for Selection of Health Status Measurement Instruments checklist was used. The Clinical COPD Questionnaire (CCQ), the self-administered Chronic Respiratory Questionnaire-Standardized, and the Medical Research Council Dyspnea Scale were used in the validation study. Test-retest reliability was estimated across 2 weeks in patients with stable COPD. Participants were patients with COPD from the Netherlands who took part in either the validation (n = 90) or reliability study (n = 60). The validity analyses showed that, as hypothesized, the household maintenance and physical exercise subscales of the Dutch version of the FPI had high correlations with the CCQ functional status domain; the total FPI had a correlation of -.44, with CCQ functional status domain. Across the subscales, score reliability estimated with Cronbach's alpha ranged from .55 (Body Care) to .97 (Household Maintenance); total score alpha was .98. Intraclass correlations (ICCs) ranged from .84 (Social Activities) to .97 (Body Care and Household Maintenance); total scale ICC was .98. Recreation and Spiritual Activity subscales varied significantly on retesting at 2 weeks. Scores on the Dutch FPI were reliable and reproducible. Evidence for validity was reasonable, but less strong than that reported in studies from other populations.

  20. Energy and resource allocation: a dynamic model of the Dutch disease. [Monograph

    SciTech Connect

    Bruno, M.; Sachs, J.

    1982-01-01

    It is well known that a domestic-response discovery gives rise to wealth effects that cause a squeeze of the tradeable-good sector of an open economy. The decline of the manufacturing sector following an energy discovery has been termed the Dutch disease, and has been investigated in many recent studies. The authors' model extends the principally static analyses to date by allowing for: (1) short-run capital specificity and long-run capital mobility; (2) international capital flows; and (3) far-sighted intertemporal optimzing behavior by households and firms. The model is solved by numerical simulation. 9 references, 4 figures, 6 tables.

  1. No genetic association of the human prolyl endopeptidase gene in the Dutch celiac disease population.

    PubMed

    Diosdado, Begoña; Stepniak, Dariusz T; Monsuur, Alienke J; Franke, Lude; Wapenaar, Martin C; Mearin, Maria Luisa; Koning, Frits; Wijmenga, Cisca

    2005-09-01

    Celiac disease (CD) is a complex genetic disorder of the small intestine. The DQ2/DQ8 human leucocyte antigen (HLA) genes explain approximately 40% of the genetic component of the disease, but the remaining non-HLA genes have not yet been identified. The key environmental factor known to be involved in the disease is gluten, a major protein present in wheat, barley, and rye. Integrating microarray data and linkage data from chromosome 6q21-22 revealed the prolyl endopeptidase (PREP) gene as a potential CD candidate in the Dutch population. Interestingly, this gene encodes for the only enzyme that is able to cleave the proline-rich gluten peptides. To investigate the role of the human PREP gene as a primary genetic factor in CD, we conducted gene expression, sequence analysis, and genetic association studies of the PREP gene and determined PREP enzyme activity in biopsies from CD patients and controls. Sequence analysis of the coding region of the PREP gene revealed two novel polymorphisms. Genetic association studies using two novel polymorphisms and three known PREP variants excluded a genetic association between PREP and CD. Determination of PREP activity revealed weak but significant differences between treated and untreated CD biopsies (P < 0.05). Our results from the association study indicate that PREP is not a causative gene for CD in the Dutch population. These are further supported by the activity determinations in which we observed no differences in PREP activity between CD patients and controls.

  2. Effects of prenatal exposure to the Dutch famine on adult disease in later life: an overview.

    PubMed

    Roseboom, T J; van der Meulen, J H; Ravelli, A C; Osmond, C; Barker, D J; Bleker, O P

    2001-12-20

    Chronic diseases are the main public health problem in Western countries. There are indications that these diseases originate in the womb. It is thought that undernutrition of the fetus during critical periods of development would lead to adaptations in the structure and physiology of the fetal body, and thereby increase the risk of diseases in later life. The Dutch famine--though a historical disaster--provides a unique opportunity to study effects of undernutrition during gestation in humans. This thesis describes the effects of prenatal exposure to the Dutch famine on health in later life. We found indications that undernutrition during gestation affects health in later life. The effects on undernutrition, however, depend upon its timing during gestation and the organs and systems developing during that critical time window. Furthermore, our findings suggest that maternal malnutrition during gestation may permanently affect adult health without affecting the size of the baby at birth. This may imply that adaptations that enable the fetus to continue to grow may nevertheless have adverse consequences of improved nutrition of pregnant women will be underestimated if these are solely based on the size of the baby at birth. Little is known about what an adequate diet for pregnant women might be. In general, women are especially receptive to advice about diet and lifestyle before and during a pregnancy. This should be exploited to improve the health of future generations.

  3. Extinguishing ELMs in detached radiative divertor plasmas

    NASA Astrophysics Data System (ADS)

    Pigarov, Alexander; Krasheninnikov, Sergei; Rognlien, Thomas

    2016-10-01

    In order to avoid deleterious effects of ELMs on PFCs in next-step fusion devices it has been suggested to operate with small-sized ELMs naturally extinguishing in the divertor. Our modeling effort is focusing at extinguishing type-I ELMs: conditions for expelled plasma dissipation; efficiency of ELM power handling by detached radiative divertors; and the ELM impact on detachment state. Here time-dependent modeling of a sequence of many ELMs was performed with 2-D edge plasma transport code UEDGE-MB-W which incorporates the Macro-Blob (MB) approach to simulate non-diffusive filamentary transport and various ``Wall'' (W) models for time-dependent hydrogen wall inventory and recycling. Three cases were modeled, in which extinguishing ELMs are achieved due to: (i) intrinsic impurities via graphite sputtering, (ii) extrinsic impurity gas puff (Ne), and (iii) =(i) +(ii). For each case, we performed a series of UEDGE-MB-W runs scanning the deuterium and impurity inventories, pedestal losses and ELM frequency. Temporal variations of the degree of detachment, ionization front shape, recombination sink strength, radiated fraction, peak power loads, OSP, impurity charge states, and in/out asymmetries were analyzed. We discuss the onset of extinguishing ELMs, conditions for not burning through and enhanced plasma recombination as functions of scanned parameters. Efficiencies of intrinsic and extrinsic impurities in ELM extinguishing are compared.

  4. Predictive testing for Huntington disease: nonparticipants compared with participants in the Dutch program.

    PubMed Central

    van der Steenstraten, I. M.; Tibben, A.; Roos, R. A.; van de Kamp, J. J.; Niermeijer, M. F.

    1994-01-01

    Attitudes toward predictive testing programs, in individuals who choose not to undertake the test (i.e., nonparticipants), may be influenced by fears of an unfavorable result. The reasons not to participate in predictive testing programs for Huntington disease (HD) were studied in members of the Dutch Huntington Association who were at 50% risk. They had completed the same baseline psychological questionnaires as had the participants in the Dutch DNA-testing program. The group of 34 nonparticipants was similar to the tested participants in the Dutch predictive testing program, with respect to average age (31.1 years), male:female ratio (1:2), the frequency of a stable relationship (70%), and level of education (67% had high school education or higher). Testing did not seem to be a realistic option for nonparticipants for improving their quality of life. In comparison with participants, nonparticipants had a significantly more pessimistic outlook on themselves and their futures. When asked to consider the possibility of an unfavorable result, nonparticipants expected more difficulties in their families; more problems for their children, their partners, and themselves; a lowered quality of life; and, more often, a depressive reaction. In their opinion, a favorable result would reduce the problems for their children but not for themselves, a result that was found more often in the nonparticipant than in the participant group. Nonparticipants learned about their being at risk for HD during adolescence (mean age 15.6 years), whereas participants did so in adulthood (mean age 22.7 years). The nonparticipants' attitude toward the test might be explained by the influence of HD in the adolescent's separation-individuation process and personality development. This finding could be relevant for future research and for the discussion about testing minors for delayed-onset disorders. PMID:7942839

  5. Alpha-chain disease with involvement of the respiratory tract in a Dutch child

    PubMed Central

    Stoop, J. W.; Ballieux, R. E.; Hijmans, W.; Zegers, B. J. W.

    1971-01-01

    A description is given of an 8-year-old girl of pure Dutch extraction who, since age 4, has shown unclassifiable skin changes, marked eosinophilia and diffuse infiltrative pulmonary changes with enlarged mediastinal lymph glands, dyspnoea and impaired diffusion. The patient's serum contained a large amount of proteins related to the Fc-fragment of IgA. She developed a pharyngeal tumour with the histological characteristics of a paragranuloma. The mucosa of the lower air passages is regarded as a possible site of origin of the abnormal serum protein. The disease was therefore interpreted as a disorder of the secretory IgA system, and this patient could well represent the respiratory form of the alpha-chain disease, described so far. ImagesFig. 3Fig. 4Fig. 5Fig. 1Fig. 2 PMID:4111693

  6. Retrospective analysis of old-age colitis in the Dutch inflammatory bowel disease population.

    PubMed

    Hadithi, Muhammed; Cazemier, Marcel; Meijer, Gerrit-A; Bloemena, Elisabeth; Felt-Bersma, Richel-J; Mulder, Chris-J; Meuwissen, Stephan-Gm; Pena, Amado-Salvador; van Bodegraven, Adriaan-A

    2008-05-28

    To describe the characteristics of Dutch patients with chronic inflammatory bowel disease (IBD) first diagnosed above 60 years of age-a disease also known as old-age colitis (OAC) and to highlight a condition that has a similar appearance to IBD, namely segmental colitis associated with diverticular disease (SCAD). A retrospective longitudinal survey of patient demographic and clinical characteristics, disease characteristics, diagnostic methods, management and course of disease was performed. The median follow-up period was 10 years. Of a total of 1100 IBD patients attending the Department of Gastroenterology, 59 (5%) [median age 82 years (range 64-101); 25 male (42%)] were identified. These patients were diagnosed with ulcerative colitis (n = 37, 61%), Crohn's disease (n = 14, 24%), and indeterminate colitis (n = 8, 15%). Remission was induced in 40 (68%) patients within a median interval of 6 mo (range 1-21) and immunosuppressive therapy was well tolerated. Histological evaluation based on many biopsy samples and the course of the disease led to other diagnosis, namely SCAD instead of IBD in five (8%) patients. OAC is not an infrequent problem for the gastroenterologist, and should be considered in the evaluation of older patients with clinical features suggestive of IBD. Extra awareness and extensive biopsy sampling are required in order to avoid an erroneous diagnosis purely based on histological mimicry of changes seen in SCAD, when diagnosing IBD in the presence of diverticulosis coli.

  7. The Dutch Parelsnoer Institute--Neurodegenerative diseases; methods, design and baseline results.

    PubMed

    Aalten, Pauline; Ramakers, Inez H G B; Biessels, Geert Jan; de Deyn, Peter Paul; Koek, Huiberdina L; OldeRikkert, Marcel G M; Oleksik, Ania M; Richard, Edo; Smits, Lieke L; van Swieten, John C; Teune, Laura K; van der Lugt, Aad; Barkhof, Frederik; Teunissen, Charlotte E; Rozendaal, Nico; Verhey, Frans R J; van der Flier, Wiesje M

    2014-12-31

    The Parelsnoer Institute is a collaboration between 8 Dutch University Medical Centers in which clinical data and biomaterials from patients suffering from chronic diseases (so called "Pearls") are collected according to harmonized protocols. The Pearl Neurodegenerative Diseases focuses on the role of biomarkers in the early diagnosis, differential diagnosis and in monitoring the course of neurodegenerative diseases, in particular Alzheimer's disease. The objective of this paper is to describe the design and methods of the Pearl Neurodegenerative Diseases, as well as baseline descriptive variables, including their biomarker profile. The Pearl Neurodegenerative Diseases is a 3-year follow-up study of patients referred to a memory clinic with cognitive complaints. At baseline, all patients are subjected to a standardized examination, including clinical data and biobank materials, e.g. blood samples, MRI and cerebrospinal fluid. At present, in total more than 1000 patients have been included, of which cerebrospinal fluid and DNA samples are available of 211 and 661 patients, respectively. First descriptives of a subsample of the data (n = 665) shows that patients are diagnosed with dementia (45%), mild cognitive impairment (31%), and subjective memory complaints (24%). The Pearl Neurodegenerative Diseases is an ongoing large network collecting clinical data and biomaterials of more than 1000 patients with cognitive impairments. The project has started with data analyses of the baseline characteristics and biomarkers, which will be the starting point of future specific research questions that can be answered by this unique dataset.

  8. ELM heat flux in the ITER divertor

    SciTech Connect

    Leonard, A.W.; Osborne, T.H.; Hermann, A.; Suttrop, W.; Itami, K.; Lingertat, J.; Loarte, A.

    1998-07-01

    Edge-Localized-Modes (ELMs) have the potential to produce unacceptable levels of erosion of the ITER divertor. Ablation of the carbon divertor target will occur if the surface temperature rises above about 2,500 C. Because a large number of ELMs, {ge}1000, are expected in each discharge it is important that the surface temperature rise due to an individual ELM remain below this threshold. Calculations that have been carried out for the ITER carbon divertor target indicate ablation will occur for ELM energy {ge}0.5MJ/m{sup 2} if it is deposited in 0.1 ms, or 1.2 MJ/m{sup 2} if the deposition time is 1.0 ms. Since {Delta}T{proportional_to}Q{Delta}t{sup {minus}1/2}, an ablation threshold can be estimated at Q{Delta}t{sup {minus}1/2}{approx}45 MJm{sup {minus}2} s{sup {minus}1/2} where Q is the divertor ELM energy density in J-m{sup {minus}2} and {Delta}t is the time in seconds for that deposition. If a significant fraction of ELMs exceed this threshold then an unacceptable level of erosion may take place. The ablation parameter in ITER can be determined by scaling four factors from present experiments: the ELM energy loss from the core plasma, the fraction of ELM energy deposited on the divertor target, the area of the ELM profile onto the target, and the time for the ELM deposition. ELM data from JET, ASDEX-Upgrade, JT-60U, DIII-D and Compass-D have been assembled by the ITER Divertor Modeling and Database expert group into a database for the purpose of predicting these factors for ELMs in the ITER divertor.

  9. LETTER: Toroidally asymmetric ELM precursors in TCV

    NASA Astrophysics Data System (ADS)

    Reimerdes, H.; Pochelon, A.; Suttrop, W.

    1998-03-01

    Coherent magnetic oscillations precede edge localized modes (ELMs) in TCV. The precursor has been detected prior to ELMs considered to be of type III and others previously referred to as TCV large ELMs. This permits the identification of both as type III ELMs according to the usual classification scheme. The strong localization of these precursors on the bad curvature side of the plasma and their medium toroidal mode numbers indicate their ballooning character. Unlike conventional MHD modes, these modes start toroidally localized and grow in amplitude and toroidal extent. When the precursor encompasses the whole toroidal circumference, the increased transport phase, as indicated by the characteristic Dα spike, begins.

  10. ELM mitigation with pellet ELM triggering and implications for PFCs and plasma performance in ITER

    DOE PAGES

    Baylor, Larry R.; Lang, P. T.; Allen, Steve L.; ...

    2014-10-05

    The triggering of rapid small edge localized modes (ELMs) by high frequency pellet injection has been proposed as a method to prevent large naturally occurring ELMs that can erode the ITER plasma facing components. Deuterium pellet injection has been used to successfully demonstrate the on-demand triggering of edge localized modes (ELMs) at much higher rates and with much smaller intensity than natural ELMs. The proposed hypothesis for the triggering mechanism of ELMs by pellets is the local pressure perturbation resulting from reheating of the pellet cloud that can exceed the local high-n ballooning mode threshold where the pellet is injected.more » Nonlinear MHD simulations of the pellet ELM triggering show destabilization of high-n ballooning modes by such a local pressure perturbation. A review of the recent pellet ELM triggering results from ASDEX Upgrade (AUG), DIII-D, and JET reveals that a number of uncertainties about this ELM mitigation technique still remain. These include the heat flux impact pattern on the divertor and wall from pellet triggered and natural ELMs, the necessary pellet size and injection location to reliably trigger ELMs, and the level of fueling to be expected from ELM triggering pellets and synergy with larger fueling pellets. The implications of these issues for pellet ELM mitigation in ITER and its impact on the PFCs are presented along with the design features of the pellet injection system for ITER.« less

  11. ELM mitigation with pellet ELM triggering and implications for PFCs and plasma performance in ITER

    SciTech Connect

    Baylor, Larry R.; Lang, P. T.; Allen, Steve L.; Combs, S. K.; Commaux, N.; Evans, Todd E.; Fenstermacher, Max E.; Huijsmans, G.; Jernigan, T. C.; Lasnier, Charles J.; Leonard, Anthony W.; Loarte, Alberto; Maingi, Rajesh; Maruyama, S.; Meitner, S. J.; Moyer, Richard A.; Osborne, Thomas H.

    2014-10-05

    The triggering of rapid small edge localized modes (ELMs) by high frequency pellet injection has been proposed as a method to prevent large naturally occurring ELMs that can erode the ITER plasma facing components. Deuterium pellet injection has been used to successfully demonstrate the on-demand triggering of edge localized modes (ELMs) at much higher rates and with much smaller intensity than natural ELMs. The proposed hypothesis for the triggering mechanism of ELMs by pellets is the local pressure perturbation resulting from reheating of the pellet cloud that can exceed the local high-n ballooning mode threshold where the pellet is injected. Nonlinear MHD simulations of the pellet ELM triggering show destabilization of high-n ballooning modes by such a local pressure perturbation. A review of the recent pellet ELM triggering results from ASDEX Upgrade (AUG), DIII-D, and JET reveals that a number of uncertainties about this ELM mitigation technique still remain. These include the heat flux impact pattern on the divertor and wall from pellet triggered and natural ELMs, the necessary pellet size and injection location to reliably trigger ELMs, and the level of fueling to be expected from ELM triggering pellets and synergy with larger fueling pellets. The implications of these issues for pellet ELM mitigation in ITER and its impact on the PFCs are presented along with the design features of the pellet injection system for ITER.

  12. Elm yellows: a widespread and overlooked killer of elm trees across the United States

    Treesearch

    Charles E. Flower; Nancy Hayes-Plazolles; Christina Rosa; James M. Slavicek

    2017-01-01

    The elm yellows phytoplasma (Candidatus Phytoplasma ulmi) is a geographically widespread pathogen that poses a significant threat to most native wild elms in North America (Ulmus americana, U. rubra, U. alata, U. crassifolia, and U. serotina) (Mäurer et al. 1993), as well as to the success of American elm...

  13. Mutation of the Alzheimer's Disease Amyloid Gene in Hereditary Cerebral Hemorrhage, Dutch Type

    NASA Astrophysics Data System (ADS)

    Levy, Efrat; Carman, Mark D.; Fernandez-Madrid, Ivan J.; Power, Michael D.; Lieberburg, Ivan; van Duinen, Sjoerd G.; Bots, Gerard Th. A. M.; Luyendijk, Willem; Frangione, Blas

    1990-06-01

    An amyloid protein that precipitates in the cerebral vessel walls of Dutch patients with hereditary cerebral hemorrhage with amyloidosis is similar to the amyloid protein in vessel walls and senile plaques in brains of patients with Alzheimer's disease, Down syndrome, and sporadic cerebral amyloid angiopathy. Cloning and sequencing of the two exons that encode the amyloid protein from two patients with this amyloidosis revealed a cytosine-to-guanine transversion, a mutation that caused a single amino acid substitution (glutamine instead of glutamic acid) at position 22 of the amyloid protein. The mutation may account for the deposition of this amyloid protein in the cerebral vessel walls of these patients, leading to cerebral hemorrhages and premature death.

  14. Novel insights into the elm yellows phytoplasma genome and into the metagenome of elm yellows-infected elms

    Treesearch

    Christina Rosa; Paolo Margaria; Scott M. Geib; Erin D. Scully

    2017-01-01

    In North America, American elms were historically present throughout the northeastern United States and southeastern Canada. The longevity of these trees, their resistance to the harsh urban environment, and their aesthetics led to their wide use in landscaping and streetscaping over several decades. American elms were one of most cultivated plants in the United States...

  15. Modelling of edge localised modes and edge localised mode control [Modelling of ELMs and ELM control

    DOE PAGES

    Huijsmans, G. T. A.; Chang, C. S.; Ferraro, N.; ...

    2015-02-07

    Edge Localised Modes (ELMs) in ITER Q = 10 H-mode plasmas are likely to lead to large transient heat loads to the divertor. In order to avoid an ELM induced reduction of the divertor lifetime, the large ELM energy losses need to be controlled. In ITER, ELM control is foreseen using magnetic field perturbations created by in-vessel coils and the injection of small D2 pellets. ITER plasmas are characterised by low collisionality at a high density (high fraction of the Greenwald density limit). These parameters cannot simultaneously be achieved in current experiments. Thus, the extrapolation of the ELM properties andmore » the requirements for ELM control in ITER relies on the development of validated physics models and numerical simulations. Here, we describe the modelling of ELMs and ELM control methods in ITER. The aim of this paper is not a complete review on the subject of ELM and ELM control modelling but rather to describe the current status and discuss open issues.« less

  16. Modelling of edge localised modes and edge localised mode control [Modelling of ELMs and ELM control

    SciTech Connect

    Huijsmans, G. T. A.; Chang, C. S.; Ferraro, N.; Sugiyama, L.; Waelbroeck, F.; Xu, X. Q.; Loarte, A.; Futatani, S.

    2015-02-07

    Edge Localised Modes (ELMs) in ITER Q = 10 H-mode plasmas are likely to lead to large transient heat loads to the divertor. In order to avoid an ELM induced reduction of the divertor lifetime, the large ELM energy losses need to be controlled. In ITER, ELM control is foreseen using magnetic field perturbations created by in-vessel coils and the injection of small D2 pellets. ITER plasmas are characterised by low collisionality at a high density (high fraction of the Greenwald density limit). These parameters cannot simultaneously be achieved in current experiments. Thus, the extrapolation of the ELM properties and the requirements for ELM control in ITER relies on the development of validated physics models and numerical simulations. Here, we describe the modelling of ELMs and ELM control methods in ITER. The aim of this paper is not a complete review on the subject of ELM and ELM control modelling but rather to describe the current status and discuss open issues.

  17. Elm-ash-cottonwood forest type bibliography.

    Treesearch

    Stephen R Shifley; Kenneth M. Brown

    1978-01-01

    Lists 679 references, arranged by author's names, on the biology, ecology, silviculture and mensuration of the elm-ash-cottonwood type and its component species. Indices for species, subjects, and second authors are appended.

  18. Characteristics of ELM precursors on NSTX

    NASA Astrophysics Data System (ADS)

    Ridha, Philipp; Menard, Jonathan; Stutman, Dan

    2005-10-01

    The precursor characteristics of Edge Localized Modes (ELMs) on NSTX were analyzed with Mirnov and USXR diagnostics in terms of toroidal mode number, growth rate, oscillation frequency, growth times before crash, and edge localization. Mode identification is especially difficult for most ELMs studied, as the precursor growth rates are often comparable to the oscillation period. Details of the mode identification process will be described. The Mirnov diagnostic does not tell whether the ELM is edge localized or not, thus the USXR array was used to discriminate between the edge and core plasma using an analysis of the X-ray emission with different metallic filters (Ti 0.4μm - E > 100eV, Be 10μm - E > 500eV, Be 100 μm - E > 1.2keV). Using the titanium filter, a strong correlation between Mirnov and USXR data during an ELM crash was observed. Analysis of the USXR data using a constrained tomographic inversion shows relative USXR fluctuation amplitudes from ELM precursors in the range of 1% to 5%. This analysis combined with an edge displacement model provides an estimate of the transient boundary displacements for typical ELMs of < 5 mm.

  19. Discussing sexuality with patients with Parkinson's disease: a survey among Dutch neurologists.

    PubMed

    van Hees, Petra J M; van der Plas, Anton A; van Ek, Gaby F; Putter, Hein; Den Oudsten, Brenda L; den Ouden, Marjolein E M; Elzevier, Henk W

    2017-03-01

    Sexual functioning is often impaired in patients with Parkinson's disease (PD) and may affect quality of life of patients and their spouse. However, little is known about the practice patterns of neurologists with regard to discussing sexuality in this field. The aim of this cross-sectional study was to evaluate to what extent neurologists discuss sexuality with PD patients. A 22-item questionnaire was sent to 139 neurologists specializing in PD. The survey contained questions about their attitudes, knowledge, and practice patterns with respect to sexual dysfunction (SD) in patients with PD. The response rate of the survey was 66.9%. Most participants (56.8%) stated that they address sexuality in less than half of their PD patients. High age of patients (42.0%), insufficient consultation time (37.5%), and a lack of patients' initiative to raise the topic themselves (36.4%) were frequently reported barriers towards discussing sexuality. The majority of participants considered that discussing sexuality is a responsibility that lay with neurologists (85.2%), nurses (73.9%), and patients (72.7%). One quarter of the neurologists reported to have insufficient or no knowledge on SD. The majority of participants regarded screening for SD important or slightly important (85.2%). A large proportion of Dutch neurologists specializing in PD do not routinely discuss sexuality with their PD patients. Sexual healthcare in PD patients may benefit from time-efficient tools and agreements on who is responsible for discussing SD. Furthermore, recommendations in PD guidelines on screening and managing SD should be adapted to fit everyday practice.

  20. The polypill in the primary prevention of cardiovascular disease: cost-effectiveness in the Dutch population.

    PubMed

    van Gils, Paul F; Over, Eelco A B; Hamberg-van Reenen, Heleen H; de Wit, G Ardine; van den Berg, Matthijs; Schuit, Albertine J; Engelfriet, Peter M

    2011-01-01

    Objectives The aim of the present study was to estimate the cost-effectiveness of the polypill in the primary prevention of cardiovascular disease. Design A health economic modelling study. Setting Primary healthcare in the Netherlands. Participants Simulated individuals from the general Dutch population, aged 45-75 years. Interventions Opportunistic screening followed by prescription of the polypill to eligible individuals. Eligibility was defined as having a minimum 10-year risk of cardiovascular death as assessed with the Systematic Coronary Risk Evaluation function of alternatively 5%, 7.5% or 10%. Different versions of the polypill were considered, depending on composition: (1) the Indian polycap, with three different types of blood pressure-lowering drugs, a statin and aspirin; (2) as (1) but without aspirin and (3) as (2) but with a double statin dose. In addition, a scenario of (targeted) separate antihypertensive and/or statin medication was simulated. Primary outcome measures Cases of acute myocardial infarction or stroke prevented, quality-adjusted life years (QALYs) gained and the costs per QALY gained. All interventions were compared with usual care. Results All scenarios were cost-effective with an incremental cost-effectiveness ratio between €7900 and 12 300 per QALY compared with usual care. Most health gains were achieved with the polypill without aspirin and containing a double dose of statins. With a 10-year risk of 7.5% as the threshold, this pill would prevent approximately 3.5% of all cardiovascular events. Conclusions Opportunistic screening based on global cardiovascular risk assessment followed by polypill prescription to those with increased risk offers a cost-effective strategy. Most health gain is achieved by the polypill without aspirin and a double statin dose.

  1. The polypill in the primary prevention of cardiovascular disease: cost-effectiveness in the Dutch population

    PubMed Central

    Over, Eelco A B; Hamberg-van Reenen, Heleen H; de Wit, G Ardine; van den Berg, Matthijs; Schuit, Albertine J; Engelfriet, Peter M

    2011-01-01

    Objectives The aim of the present study was to estimate the cost-effectiveness of the polypill in the primary prevention of cardiovascular disease. Design A health economic modelling study. Setting Primary healthcare in the Netherlands. Participants Simulated individuals from the general Dutch population, aged 45–75 years. Interventions Opportunistic screening followed by prescription of the polypill to eligible individuals. Eligibility was defined as having a minimum 10-year risk of cardiovascular death as assessed with the Systematic Coronary Risk Evaluation function of alternatively 5%, 7.5% or 10%. Different versions of the polypill were considered, depending on composition: (1) the Indian polycap, with three different types of blood pressure-lowering drugs, a statin and aspirin; (2) as (1) but without aspirin and (3) as (2) but with a double statin dose. In addition, a scenario of (targeted) separate antihypertensive and/or statin medication was simulated. Primary outcome measures Cases of acute myocardial infarction or stroke prevented, quality-adjusted life years (QALYs) gained and the costs per QALY gained. All interventions were compared with usual care. Results All scenarios were cost-effective with an incremental cost-effectiveness ratio between €7900 and 12 300 per QALY compared with usual care. Most health gains were achieved with the polypill without aspirin and containing a double dose of statins. With a 10-year risk of 7.5% as the threshold, this pill would prevent approximately 3.5% of all cardiovascular events. Conclusions Opportunistic screening based on global cardiovascular risk assessment followed by polypill prescription to those with increased risk offers a cost-effective strategy. Most health gain is achieved by the polypill without aspirin and a double statin dose. PMID:22189351

  2. The impact of ELMs on the ITER divertor

    SciTech Connect

    Leonard, A.W.; Osborne, T.H.; Suttrop, W.; Hermann, A.; Itami, K.; Lingertat, J.; Loarte, A.

    1998-07-01

    Edge-Localized-Modes (ELMs) are expected to present a significant transient flux of energy and particles to the ITER divertor. The threshold for ablation of the graphite target will be reached if the ELM transient exceeds Q/t{sup 1/2} {approximately} 45 MJ-m{sup {minus}2}-s{sup {minus}1/2} where Q is the ELM deposition energy density and t is the ELM deposition time. The ablation parameter in ITER can be determined by scaling four factors from present experiments: the ELM energy loss from the core plasma, the fraction of ELM energy deposited on the divertor target, the area of the ELM profile onto the target, and finally the time for the ELM deposition. Review of the ELM energy loss of Type 1 ELM data suggests an ITER ELM energy loss of 2--6% of the stored energy or 25--80 MJ. The fraction of heating power crossing the separatrix due to ELMs is nearly constant (20--40%) resulting in an inverse relationship between ELM amplitude and frequency. Measurements on DIII-D and ASDEX-Upgrade indicate that 50--80% of the ELM energy is deposited on the target. There is currently no evidence for a large fraction of the ELM energy being dissipated through radiation. Profiles of the ELM heat flux are typically 1--2 times the width of steady heat flux between ELMs, with the ELM amplitude usually larger on the inboard target. The ELM deposition time varies from about 0.1 ms in JET to as high as 1.0 ms in ASDEX-Upgrade and DIII-D. The ELM deposition time for ITER will depend upon the level of conductive versus convective transport determined by the ratio of energy to particles released by the ELM. Preliminary analysis suggests that large Type 1 ELMs for low recycling H-mode may exceed the ablation parameter by a factor of 5. Promising regimes with smaller ELMS have been found at other edge operational regimes, including high density with gas puffing, use of rf heating and operation with Type 3 ELMs.

  3. The role of ELM filaments in setting the ELM wetted area in MAST and the implications for future devices

    NASA Astrophysics Data System (ADS)

    Thornton, A. J.; Allan, S. Y.; Dudson, B. D.; Elmore, S. D.; Fishpool, G. M.; Harrison, J. R.; Kirk, A.; The MAST Team; The EUROfusion MST1 Team

    2017-01-01

    The ELM wetted area is a key factor in the peak power load during an ELM, as it sets the region over which the ELM energy is deposited. The deposited heat flux at the target is seen to have striations in the profiles that are generated by the arrival of filaments ejected from the confined plasma. The effect of the filaments arriving at the target on the ELM wetted area, and the relation to the midplane mode number is investigated in this paper using infrared (IR) thermography and high speed visible imaging (>10 kHz). Type I ELMs are analysed, as these have the largest heat fluxes and are observed to have toroidal mode numbers of between 5 and 15. The IR profiles during the ELMs show clear filamentary structures that evolve during the ELM cycle. An increasing number of striations at the target is seen to correspond to an increase in the wetted area. Analysis shows that the ratio of the ELM wetted area to the inter-ELM wetted area, a key parameter for ITER, for the type I ELMs is between 3 and 6 for lower single null plasmas and varies with the ELM midplane mode number, as determined by visible measurements. Monte-Carlo modelling of the ELMs is used to understand the variation seen in the wetted area and the effect of an increased mode number; the modelling replicates the trends seen in the experimental data and supports the observation of increased toroidal mode number generating larger target ELM wetted areas. ITER is thought to be peeling unstable which would imply a lower ELM mode number compared to MAST which is peeling-ballooning unstable. The results of this analysis suggest that the lower n peeling unstable ELMs expected for ITER will have smaller wetted areas than peeling-ballooning unstable ELMs. A smaller wetted area will increase the level of ELM control required, therefore a key prediction required for ITER is the expected ELM mode number.

  4. Solitary magnetic perturbations at the ELM onset

    NASA Astrophysics Data System (ADS)

    Wenninger, R. P.; Zohm, H.; Boom, J. E.; Burckhart, A.; Dunne, M. G.; Dux, R.; Eich, T.; Fischer, R.; Fuchs, C.; Garcia-Munoz, M.; Igochine, V.; Hölzl, M.; Luhmann N., C., Jr.; Lunt, T.; Maraschek, M.; Müller, H. W.; Park, H. K.; Schneider, P. A.; Sommer, F.; Suttrop, W.; Viezzer, E.; the ASDEX Upgrade Team

    2012-11-01

    Tokamak H-mode plasmas frequently exhibit edge-localized modes (ELMs). ELMs allow maintaining sufficient plasma purity and thus enable stationary H-mode. On the other hand in a future device ELMs may cause divertor power flux densities far in excess of tolerable material limits. The size of the energy loss per ELM is determined by saturation effects in the non-linear phase of the ELM, which at present is hardly understood. ASDEX Upgrade is now equipped with a set of fast sampling diagnostics, which is well suited to investigate the chain of events around the ELM crash with appropriate temporal resolution (⩽10 µs). Solitary magnetic perturbations (SMPs) are identified as dominant features in the radial magnetic fluctuations below 100 kHz. They are typically observed close (±100 µs) to the onset of pedestal erosion. SMPs are field aligned structures rotating in the electron diamagnetic drift direction with perpendicular velocities of about 10 km s-1. A comparison of perpendicular velocities suggests that the perturbation evoking SMPs is located at or inside the separatrix. Analysis of very pronounced examples showed that the number of peaks per toroidal turn is 1 or 2, which is clearly lower than the corresponding numbers in linear stability calculations. In combination with strong peaking of the magnetic signals this results in a solitary appearance resembling modes like palm tree modes, edge snakes or outer modes. This behaviour has been quantified as solitariness and correlated with main plasma parameters. SMPs may be considered as a signature of the non-linear ELM phase originating at the separatrix or further inside. Thus they provide a handle to investigate the transition from linear to non-linear ELM phase. By comparison with data from gas puff imaging processes in the non-linear phase at or inside the separatrix and in the scrape-off layer (SOL) can be correlated. A connection between the passing of an SMP and the onset of radial filament propagation has

  5. Foot-and-Mouth disease control using vaccination: the Dutch experience in 2001.

    PubMed

    Pluimers, F H

    2004-01-01

    A first case of foot-and-mouth disease (FMD) was confirmed on a farm in Oene on 21 March 2001. The Dutch eradication strategy for the area which is densely populated with susceptible animals was immediately applied: stamping out the infected herd and pre-emptive culling of all susceptible animals on farms within a radius of 1 km around an infected farm. If the organisation was unable to cull infected herds within 24 hours after detection and the neighbouring farms within four days, emergency ring vaccination would be applied. By 26 March it was clear that capacity problems prevented the required rapid culling and therefore the decision to apply emergency vaccination was taken. On 28 March vaccination of all susceptible animals was started in 2 km zones around infected farms. In the area where the first outbreak occurred, by 1 April 11 farms were found to be infected. Tracing the links between these infections was difficult, the farms being at a greater distance than 4 km from each other and fear increased that the disease could not be contained in this area. It was therefore decided to vaccinate a larger area: "Vaccination area Noord Veluwe". Suppressive vaccination was chosen. This implied that all vaccinated animals should be killed and destroyed. Vaccination rapidly reduced the number of new infections. In total 26 farms became infected with FMD. The last affected farm was confirmed on 22 April 2001. The last vaccinated animal was culled on 25 May 2001. EU rules also gave the option of choosing protective vaccination. The consequence was that only vaccinated cattle could stay alive. The status 'FMD-free without vaccination' however would then be recovered 12 months after the last outbreak. This consequence was too damaging to the export interests of the country. The killing of healthy vaccinated animals became the predominant factor in the discussion of farmers, politicians and the general public. The need for adjustments in the FMD eradication strategy and in

  6. Effects of prenatal exposure to the Dutch famine on adult disease in later life: an overview.

    PubMed

    Roseboom, T J; van der Meulen, J H; Ravelli, A C; Osmond, C; Barker, D J; Bleker, O P

    2001-10-01

    People who were small at birth have been shown to have an increased risk of CHD and chronic bronchitis in later life. These findings have led to the fetal origins hypothesis that proposes that the fetus adapts to a limited supply of nutrients, and in doing so it permanently alters its physiology and metabolism, which could increase its risk of disease in later life. The Dutch famine--though a historical disaster--provides a unique opportunity to study effects of undernutrition during gestation in humans. People who had been exposed to famine in late or mid gestation had reduced glucose tolerance. Whereas people exposed to famine in early gestation had a more atherogenic lipid profile, somewhat higher fibrinogen concentrations and reduced plasma concentrations of factor VII, a higher BMI and they appeared to have a higher risk of CHD. Though the latter was based on small numbers, as could be expected from the relatively young age of the cohort. Nevertheless, this is the first evidence in humans that maternal undernutrition during gestation is linked with the risk of CHD in later life. Our findings broadly support the hypothesis that chronic diseases originate through adaptations made by the fetus in response to undernutrition. The long-term effects of intrauterine undernutrition, however, depend upon its timing during gestation and on the tissues and systems undergoing critical periods of development at that time. Furthermore, our findings suggest that maternal malnutrition during gestation may permanently affect adult health without affecting the size of the baby at birth. This gives the fetal origins hypothesis a new dimension. It may imply that adaptations that enable the fetus to continue to grow may nevertheless have adverse consequences for health in later life. CHD may be viewed as the price paid for successful adaptations to an adverse intra-uterine environment. It also implies that the long-term consequences of improved nutrition of pregnant women will be

  7. The global build-up to intrinsic ELM bursts and comparison with pellet triggered ELMs seen in JET

    NASA Astrophysics Data System (ADS)

    Chapman, S. C.; Dendy, R. O.; Lang, P. T.; Watkins, N. W.; Calderon, F. A.; Romanelli, M.; Todd, T. N.; Contributors, JET

    2017-02-01

    We focus on JET plasmas in which ELMs are triggered by pellets in the presence of ELMs which occur naturally. We perform direct time domain analysis of signals from fast radial field coils and toroidal full flux azimuthal loops. These toroidally integrating signals provide simultaneous high time resolution measurements of global plasma dynamics and its coupling to the control system. We examine the time dynamics of these signals in plasmas where pellet injection is used to trigger ELMs in the presence of naturally occurring ELMs. Pellets whose size and speed are intended to provide maximum local perturbation for ELM triggering are launched at pre-programmed times, without correlation to the occurrence times of intrinsic ELMs. Pellet rates were sufficiently low to prevent sustained changes of the underlying plasma conditions and natural ELM behaviour. We find a global signature of the build-up to natural ELMs in the temporal analytic phase of both the full flux loops and fast radial field coil signals. Before a natural ELM, the signal phases align to the same value on a ˜ 2-5 ms timescale. This global build up to a natural ELM occurs whilst the amplitude of the full flux loop and fast radial field coil signals are at their background value: it precedes the response seen in these signals to the onset of ELMing. In contrast these signals do not clearly phase align before the ELM for ELMs which are the first to occur following pellet injection. This provides a direct test that can distinguish when an ELM is triggered by a pellet as opposed to occurring naturally. It further supports the idea [1-4] of a global build up phase that precedes natural ELMs; pellets can trigger ELMs even when the signal phase is at a value when a natural ELM is unlikely to occur.

  8. ELM-induced W sputtering sources in JET

    NASA Astrophysics Data System (ADS)

    Brezinsek, S.; den Harder, N.; Guillemaut, C.

    2015-11-01

    JET equipped with Be wall and W divertor showed after one year of operation intact W surfaces at the target plates. Eroded W from both divertor legs contributes to the total W source and content in the plasma. Detailed analysis of the intra-ELM and inter-ELM W source in H-mode discharges has been carried out using spectroscopy of W, D and Be emission and, independently, using ECE and LP to determine respectively the ion impact energies and fluxes to the target plate. The inter-ELM W source can be eliminated in detached conditions due to impact energies below the sputtering threshold, leaving the intra-ELM source to be the dominant one (80%). Comparison between inner and outer divertor showed that both sources are comparable in the intra-ELM phase. Dedicated composition analysis reveals that sputtering by Be ions can account for the residual inter-ELM source, but cannot explain the intra-ELM source due to the low Be concentration in the plasma (1%). D + with energies above 1keV dominate the intra-ELM W sputtering whereas in the inter-ELM phase energies of D + are below the threshold. These energetic ions are transported from the pedestal region to the target plate during ELM excursion. The W source and content as function of the ELM frequency and ion impact energy has been studied for a set of plasmas showing initially a linear increase before decoupling due to ELM-flushing of W from the confined region sets in at about 40Hz. The range of ELM frequencies in JET covers the frequencies predicted for the ITER H-mode baseline scenarios with ELM pacing and detached inter-ELM phase. The W source in ITER will be determined by the intra-ELM phase.

  9. 1. EXTERIOR VIEW OF ELM CITY PLANT (A. FRANCIS WALKER, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. EXTERIOR VIEW OF ELM CITY PLANT (A. FRANCIS WALKER, 1905-07) FROM SECOND AVENUE ON OPPOSITE SIDE OF ENTRANCE. THIS STRUCTURE WAS ORIGINALLY BUILT AS THE ELM CITY COTTON MILL OF CALLAWAY MILLS. NOTE RESERVOIR IN FOREGROUND. THIS PHOTOGRAPH IS THE LEFT SIDE OF A PANORAMA VIEW THAT INCLUDES HAER Nos. GA-128-2 AND GA-128-3. - Elm City Cotton Mill, 1000 Elm Street, La Grange, Troup County, GA

  10. 3. RIGHT SIDE OF PANORAMA VIEW OF REAR OF ELM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. RIGHT SIDE OF PANORAMA VIEW OF REAR OF ELM CITY PLANT FROM SECOND AVENUE. NOTE BOILER STACK ON LEFT. THE FULLER E. CALLAWAY MEMORIAL CLOCK TOWER IS THE POINTED STRUCTURE IN THE DISTANCE TO THE RIGHT OF THE TELEPHONE POLE. - Elm City Cotton Mill, 1000 Elm Street, La Grange, Troup County, GA

  11. 2. CENTER PORTION OF PANORAMA VIEW OF REAR OF ELM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. CENTER PORTION OF PANORAMA VIEW OF REAR OF ELM CITY PLANT FROM SECOND AVENUE. NOTE ORIGINAL WATER TANK TOWER IN CENTER AND NEWER ADDITIONS TO THIS STILL OPERATIONAL TEXTILE MILL. - Elm City Cotton Mill, 1000 Elm Street, La Grange, Troup County, GA

  12. Antibiotic Injections Control Elm Phloem Necrosis in the Urban Ecosystem

    Treesearch

    T. H. Filer

    1976-01-01

    When nine American and cedar elms showing symptoms of elm phloem necrosis were given repeated injections of tetracycline antibiotics for several years, all treated trees recovered and appeared healthy by 1976. All but one of the untreated checks died. Of 10 severely infected American elms treated only during the summer of 1972, seven died and the other three showed...

  13. Energy loss for grassy ELMs and effects of plasma rotation on the ELM characteristics in JT-60U

    NASA Astrophysics Data System (ADS)

    Oyama, N.; Sakamoto, Y.; Isayama, A.; Takechi, M.; Gohil, P.; Lao, L. L.; Snyder, P. B.; Fujita, T.; Ide, S.; Kamada, Y.; Miura, Y.; Oikawa, T.; Suzuki, T.; Takenaga, H.; Toi, K.; JT-60 Team

    2005-08-01

    The energy loss for grassy edge localized modes (ELMs) has been studied to investigate the applicability of the grassy ELM regime to ITER. The grassy ELM regime is characterized by high frequency periodic collapses of 800-1500 Hz, which is ~15 times faster than that for type I ELMs. The divertor peak heat flux due to grassy ELMs is less than 10% of that for type I ELMs. This smaller heat flux is caused by a narrower radial extent of the collapse of the temperature pedestal. The different radial extent between type I ELMs and grassy ELMs agrees qualitatively with the different radial distribution of the eigenfunctions as determined from ideal MHD stability analysis. The dominant ELM energy loss for grassy ELMs appears to be caused by temperature reduction, and its ratio to the pedestal stored energy was 0.4-1%. This ratio is lower by a factor of about 10 than that for type I ELMs, which typically have between 2-10% fractional loss of the pedestal energy. A systematic study of the effects of counter (CTR) plasma rotation on the ELM characteristics has been performed using a combination of tangential and perpendicular neutral beam injections (NBIs) in JT-60U. In the high plasma triangularity (δ) regime, ELM characteristics (e.g. amplitude, frequency and type) can be changed from type I ELMs to high frequency grassy ELMs as the CTR plasma rotation is increased. On the other hand, in the low δ regime, complete ELM suppression (QH-mode) can be sustained for long periods up to 3.4 s (~18τE or energy confinement times), when the plasma position in terms of the clearance between the first wall and the plasma separatrix is optimized during the application of CTR-NBIs. In JT-60U, a transient QH phase was also observed during the CO-NBI phase with almost no net toroidal rotation at the plasma edge.

  14. The banded elm bark beetle: A new threat to elms in North America

    Treesearch

    Jose F. Negron; Jeffrey J. Witcosky; Robert J. Cain; James R. LaBonte; Donald A. Duerr; Sally J. McElwey; Jana C. Lee; Steven J. Seybold

    2005-01-01

    An exotic bark beetle from Asia, the banded elm bark beetle, Scolytus schevyrewi, has been discovered in 21 states of the United States. Although its point of entry is not known, a survey of museum specimens suggests that it has been in the US for at least 10 years. It is most abundant in western states, attacks primarily American and Siberian elms, and carries spores...

  15. ELM experimental study on the EAST Tokamak

    NASA Astrophysics Data System (ADS)

    Liu, Zixi; Gao, Xiang; Xu, Xueqiao; Li, Jiangang; EAST Team

    2013-10-01

    Atypical Type III ELM is observed on EAST tokamak. This type of ELM has MHD precursor and high collisionality at the edge, and also the threshold power is close to the scaling law. But the frequency of the ELM does not decrease with the injected power. Power threshold is lower with the molybdenum wall in double null (DN) on EAST. Considering the effects of the plasma surface (S) to the threshold power, Double Null has the lowest power threshold. Better energy confinement has been observed in DN compared to Single-null (SN) at same power loss. But with the same power loss, Upper Single Null (USN) with the grad-B drift pointing backwards the active X-point (favorable direction) on EAST has the lower energy confinement time than Lower Single Null (LSN). Low Hybrid Wave (LHW) can mitigate ELMs. The power deposition should be near the edge in the H-mode phase. Not only the LHW decreases the max gradient of the density in the pedestal region, but also brings the density oscillations. Low X-point configurations in Lower single null have a lower power threshold. The low X-point discharges on EAST is closer to the DN. Approaching to the DN configuration should be the reason of the lower power threshold caused by the lower X-point on EAST.

  16. ELM structure in the boundary plasma on COMPASS-D

    NASA Astrophysics Data System (ADS)

    Fielding, S. J.; Axon, K. B.; Booth, M. G.; Buttery, R. J.; Dowling, J.; Gates, D.; Hunt, C.; Silva, C.; Valovic, M.

    1997-02-01

    ELM experimental analysis on COMPASS-D, which has previously catalogued magnetic precursor behaviour, has been extended to consider effects in the SOL. ELM precursors are observed at the divertor. Profile changes are measured with high resolution and power and particle losses in ELMs are estimated. High speed videos of an ELM show a turbulent edge extending to the outboard limiter, in broad agreement with reciprocating probe observations. A model which describes well the magnetic features of the ELM, is being extended to include predictions of power deposition structure at the divertor target, for comparison with experimental data.

  17. Statistical physics of inter-ELM time interval sequences

    NASA Astrophysics Data System (ADS)

    Webster, Anthony; Dendy, Richard; Chapman, Sandra; JET-EFDA Team

    2013-10-01

    We report recent studies of the statistical properties of the sequence of time intervals between successive edge localised modes (ELMs). We have compared theoretically derived and empirical probability density functions (pdfs) for the waiting time intervals between ELMs from 85 long steady H-mode plasmas from the Joint European Torus (JET). The Weibull distribution provides a good fit to both type I and type III ELMs, with different parameters. We infer (A J Webster and R O Dendy, Phys Rev Lett 110, 155004 (2013)) that the type III ELMs were generated by a memoryless process, whereas the type I ELMs were consistent with build-up and release. Delay time analysis (F A Calderon, R O Dendy, S C Chapman, A J Webster et al., Phys. Plasmas 20, 042306 (2013)) of six similar JET H-mode plasmas with different levels of gas puffing strongly suggests that the underlying ELMing process is low dimensional. A current study of a dataset of 15,000 ELMs from two weeks of equivalent JET plasmas yields a combined pdf for inter-ELM time intervals which, surprisingly, displays a series of sharp maxima. All three studies show that rigorous statistical analysis of inter-ELM time intervals can contribute to quantitative classification of ELM types and to physical insight into the ELMing processes.

  18. Diseases of flounder ( Platichthys Flesus L.) in the Dutch Wadden Sea, and their relation to stress factors

    NASA Astrophysics Data System (ADS)

    Dick Vethaak, A.

    In 1988 a survey was conducted on the occurrence of gross pathologies in flounder ( Platichthys flesus L.) in the Dutch Wadden Sea in relation to stress factors, especially near fresh-water drainage sluices. A total of 9608 flounder were collected from 16 sites in June and September. Diseases recorded were: skin ulcers (affecting 7.7% of fish); fin rot (2.8%; only included in the study in September); lymphocystis (3.7%); skeletal deformities (0.3%); liver nematode infections (5.0%); intestinal cysts of the parasite Glugea sp. (0.4%); and liver nodules (pre-neoplastic and neoplastic lesions) (< 0.1%). Prevalences of skin ulcers and fin rot in Wadden Sea flounder are considerably higher than in those captured off the Dutch North Sea coast or in the Elbe estuary in Germany. These high disease levels in the Wadden Sea, however, are largely due to extremely high prevalences of skin ulcers observed near the drainage sluices of Lake IJssel, indicating a localized effect. Fin rot occurs at relatively high prevalences over the whole study area, but the data should be interpreted with some caution, due to diagnostic problems. Associations with possible disease determinants were investigated and causal hypotheses formulated. In general fish seem to develop skin diseases at sites with strong salinity fluctuations. Nutritional deficiencies possibly related to strong salinity fluctuations, high bacterial loads in the environment and obstacles to fish migration through sluices are amongst the most likely factors determining the locally high levels of skin ulcers. Although not established, it is possible that pollution-related factors and contaminant bioavailability are important. The stress imposed by a combination of these factors may adversely affect the immune system, making the fish vulnerable to opportunistic bacterial infection.

  19. OP-ELM: optimally pruned extreme learning machine.

    PubMed

    Miche, Yoan; Sorjamaa, Antti; Bas, Patrick; Simula, Olli; Jutten, Christian; Lendasse, Amaury

    2010-01-01

    In this brief, the optimally pruned extreme learning machine (OP-ELM) methodology is presented. It is based on the original extreme learning machine (ELM) algorithm with additional steps to make it more robust and generic. The whole methodology is presented in detail and then applied to several regression and classification problems. Results for both computational time and accuracy (mean square error) are compared to the original ELM and to three other widely used methodologies: multilayer perceptron (MLP), support vector machine (SVM), and Gaussian process (GP). As the experiments for both regression and classification illustrate, the proposed OP-ELM methodology performs several orders of magnitude faster than the other algorithms used in this brief, except the original ELM. Despite the simplicity and fast performance, the OP-ELM is still able to maintain an accuracy that is comparable to the performance of the SVM. A toolbox for the OP-ELM is publicly available online.

  20. Validation of BOUT++ ELM simulations for the EAST Tokamak discharges

    NASA Astrophysics Data System (ADS)

    Liu, Zixi; Xu, Xueqiao; Gao, Xiang; Liu, Shaocheng; Xia, Tianyang; Xu, Guosheng; Li, Jianggang; EAST Team

    2013-10-01

    EAST ELM experiments validate BOUT++ predictions that low-n modes become dominant at high plasma current, and the bright stripes from visible camera on EAST match ELM filamentary structures of BOUT++ simulations. Four phases of the ELM dynamics including linear growth, nonlinear saturation, pedestal crash, and L-mode-like post-ELM state have been observed in BOUT++ simulations. The simulated radial velocity of ELM explosive event is consistent with the experimental data by Gas Puffing Image (GPI). Energy loss is about 2 percent; more particle and power fluxes are deposited on the outer divertor plate. The small ELMs on EAST are resistive ballooning modes, and higher plasma current and the pressure result in higher growth rate for the lower toroidal numbers. Effect of the diamagnetic drift is stronger than the ballooning instability drive when the pressure gradient increases and the ELM crashes start at the outer mid-plane.

  1. Transport and MHD simulations of intrinsic and pellet induced ELMs

    NASA Astrophysics Data System (ADS)

    Kim, Ki Min; Na, Yong-Su; Yi, Sumin; Kim, Hyunseok; Kim, Jin Yong

    2010-11-01

    Verification of ELM mechanism and demonstration of ELM control are important issues in current fusion researches targeting ITER and DEMO. This work investigates the physics and operational characteristics of intrinsic and pellet induced ELMs throughout transport simulations using 1.5 D transport codes (C1.5/ASTRA) and MHD simulations using M3D code. Transport simulations are focused on prediction of the global parameters such as ELM energy loss in the type-I ELMy H-mode discharges with and without pellet pace making to examine an applicability of pellet injection for ELM mitigation in KSTAR and ITER. On the other hand, MHD simulations are conducted to explore the physics of intrinsic and pellet induced ELMs by applying the artificial free energy sources of velocity stream and density perturbations on the marginally stable equilibrium, respectively. Similarities and differences of triggering phenomena between intrinsic and pellet induced ELMs are discussed from the MHD approach.

  2. Use of protoplast, cell, and shoot tip culture in an elm germ plasm improvement program

    Treesearch

    R. Daniel Lineberger; M.B. Sticklen; P.M. Pijut; Mark A. Kroggel; C.V.M. Fink; S.C. Domir

    1990-01-01

    An elm germplasm improvement program was established using three distinct approaches: (1) development of protoplast regeneration protocols with the goal of attempting somatic hybridization between Ulmus americana and disease resistant hybrids; (2) evaluation of the extent of somaclonal variation in plants regenerated from protoplasts; and (3)...

  3. Colloquial Dutch.

    ERIC Educational Resources Information Center

    Bloomfield, Leonard

    This course in colloquial Dutch was originally prepared for use by American Armed Forces personnel who needed to develop a working command of the spoken language in a short period of time. Thirty-one lessons, based on activities common to Dutch culture, are contained in the text. Each lesson provides three parallel columns of sentences: the…

  4. Colloquial Dutch.

    ERIC Educational Resources Information Center

    Bloomfield, Leonard

    This course in colloquial Dutch was originally prepared for use by American Armed Forces personnel who needed to develop a working command of the spoken language in a short period of time. Thirty-one lessons, based on activities common to Dutch culture, are contained in the text. Each lesson provides three parallel columns of sentences: the…

  5. Edge Localised Modes (ELMs): Experiments and Theory

    SciTech Connect

    Connor, J. W.; Kirk, A.

    2008-05-14

    Edge Localised Modes (ELMs) are periodic disturbances of the plasma periphery occurring in tokamaks with an H-mode edge transport barrier. As a result, a fraction of the plasma energy present in the confined hot edge plasma is transferred to the open field lines in the divertor region, ultimately appearing at the divertor target plates. These events can result in high transient heat loads being deposited on the divertor target plates in large tokamaks, potentially causing damage in devices such as ITER. Consequently it is important to find means to mitigate their effects, either avoiding them or, at least, controlling them. This in turn means it is essential to understand the physics causing ELMs so that appropriate steps can be taken. It is generally agreed that ELMs originate as MHD instability caused by the steep plasma pressure gradients or edge plasma current present in H-mode, the so-called 'peeling-ballooning' model. Normally this is considered to be an ideal MHD instability but resistivity may be involved. Much less clear is the non-linear evolution of these instabilities and the mechanisms by which the confined edge plasma is transferred to the divertor plasma. There is evidence for the non-linear development of 'filamentary' structures predicted by theory, but the reconnection processes by which these are detached from the plasma core remain uncertain. In this paper the experimental and theoretical evidence for the peeling-ballooning model is presented, drawing data from a number of tokamaks, e.g. JET, DIII-D, ASDEX-Upgrade, MAST etc. Some theoretical models for the non-linear evolution of ELMs are discussed; as well as ones related to the 'peeling-ballooning' model, other candidate models for the ELM cycle are mentioned. The consequential heat loads on divertor target plates are discussed. Based on our current understanding of the physics of ELMs, means to avoid them, or mitigate their consequences, are described, e.g. the use of plasma shaping or

  6. Toward integrated multi-scale simulations for a full ELM cycle with ELM dynamics

    NASA Astrophysics Data System (ADS)

    Xu, Xueqiao

    2015-11-01

    The high-fidelity BOUT + + two-fluid and Gyro-Landau-Fluid code suites have demonstrated significant recent progresses toward integrated multi-scale simulations for a full ELM cycle with ELM dynamics. In order to improve the computational efficiency for a full ELM cycle with ELM dynamics, the basic set of dynamical equations has been separated into equations in the fluctuating and averaged parts over binormal direction. The two parts are advanced together in time but with different time steps, and dynamically exchange the turbulence fluxes and averaged profiles. Nonlinear ELM simulations show three stages of an ELM event: (1) a linear growing phase; (2) a fast crash phase; and (3) a slow inward propagation phase lasting until the core heating flux balances the ELM energy loss and the ELM is terminated. To better understand the inter-ELM pedestal dynamics during the pedestal recovery, BOUT + + simulations started from a kinetic equilibrium reconstruction using measured plasma profiles from DIII-D show that quasi-coherent fluctuations (QCFs) can provide the necessary transport to limit and saturate the H-mode pedestal gradient. The simulations predict that (1) QCFs are localized in the pedestal region as observed on DIII-D; (2) the QCFs are near marginal instability for ideal ballooning modes combined with drift-Alfven wave modes; (3) the dominant mode is around n =15, kθρi = 0.034, comparable to the measured value of 0.04; (4) the frequency of the mode is around 80kHz, close to that of the measured QCF; and (5) particle transport is smaller than the heat transport. BOUT + + simulations have also been performed to elucidate the nature and underlying physics mechanisms of the weakly-quasi-coherent mode (WCM) with higher collisionality, which causes particle transport in I-mode pedestals of Alcator C-Mod. Key simulation results are that (1) there is no ideal peeling-ballooning mode instability for the I-mode studied; (2) a strong instability exists at n >= 20; (3

  7. Climate Change and Infectious Disease Risk in Western Europe: A Survey of Dutch Expert Opinion on Adaptation Responses and Actors

    PubMed Central

    Akin, Su-Mia; Martens, Pim; Huynen, Maud M.T.E.

    2015-01-01

    There is growing evidence of climate change affecting infectious disease risk in Western Europe. The call for effective adaptation to this challenge becomes increasingly stronger. This paper presents the results of a survey exploring Dutch expert perspectives on adaptation responses to climate change impacts on infectious disease risk in Western Europe. Additionally, the survey explores the expert sample’s prioritization of mitigation and adaptation, and expert views on the willingness and capacity of relevant actors to respond to climate change. An integrated view on the causation of infectious disease risk is employed, including multiple (climatic and non-climatic) factors. The results show that the experts consider some adaptation responses as relatively more cost-effective, like fostering interagency and community partnerships, or beneficial to health, such as outbreak investigation and response. Expert opinions converge and diverge for different adaptation responses. Regarding the prioritization of mitigation and adaptation responses expert perspectives converge towards a 50/50 budgetary allocation. The experts consider the national government/health authority as the most capable actor to respond to climate change-induced infectious disease risk. Divergence and consensus among expert opinions can influence adaptation policy processes. Further research is necessary to uncover prevailing expert perspectives and their roots, and compare these. PMID:26295247

  8. Climate Change and Infectious Disease Risk in Western Europe: A Survey of Dutch Expert Opinion on Adaptation Responses and Actors.

    PubMed

    Akin, Su-Mia; Martens, Pim; Huynen, Maud M T E

    2015-08-18

    There is growing evidence of climate change affecting infectious disease risk in Western Europe. The call for effective adaptation to this challenge becomes increasingly stronger. This paper presents the results of a survey exploring Dutch expert perspectives on adaptation responses to climate change impacts on infectious disease risk in Western Europe. Additionally, the survey explores the expert sample's prioritization of mitigation and adaptation, and expert views on the willingness and capacity of relevant actors to respond to climate change. An integrated view on the causation of infectious disease risk is employed, including multiple (climatic and non-climatic) factors. The results show that the experts consider some adaptation responses as relatively more cost-effective, like fostering interagency and community partnerships, or beneficial to health, such as outbreak investigation and response. Expert opinions converge and diverge for different adaptation responses. Regarding the prioritization of mitigation and adaptation responses expert perspectives converge towards a 50/50 budgetary allocation. The experts consider the national government/health authority as the most capable actor to respond to climate change-induced infectious disease risk. Divergence and consensus among expert opinions can influence adaptation policy processes. Further research is necessary to uncover prevailing expert perspectives and their roots, and compare these.

  9. Risk factors of work disability in patients with inflammatory bowel disease--a Dutch nationwide web-based survey: work disability in inflammatory bowel disease.

    PubMed

    van der Valk, Mirthe E; Mangen, Marie-Josée J; Leenders, Max; Dijkstra, Gerard; van Bodegraven, Ad A; Fidder, Herma H; de Jong, Dirk J; Pierik, Marieke; van der Woude, C Janneke; Romberg-Camps, Mariëlle J L; Clemens, Cees H M; Jansen, Jeroen M; Mahmmod, Nofel; van de Meeberg, Paul C; van der Meulen-de Jong, Andrea E; Ponsioen, Cyriel Y; Bolwerk, Clemens J M; Vermeijden, J Reinoud; Siersema, Peter D; van Oijen, Martijn G H; Oldenburg, Bas

    2014-07-01

    Inflammatory bowel disease (IBD) is associated with high costs to society. Few data on the impact of IBD on work disability and potential predictive factors are available. To assess the prevalence of and predictive factors for work disability in Crohn's disease (CD) and ulcerative colitis (UC). A web-based questionnaire was sent out in seven university hospitals and seven general hospitals in the Netherlands. Initially, 3050 adult IBD patients were included in this prospective, nationwide cohort study, whereof 2629 patients were within the working-age (18-64 years). We used the baseline questionnaire to assess the prevalence rates of work disability in CD and UC patients within working-age. Prevalence rates were compared with the Dutch background population using age- and sex-matched data obtained from Statistics Netherlands. Multivariable logistic regression analyses were performed to identify independent demographic- and disease-specific risk factors for work disability. In CD, 18.3% of patients was fully disabled and 8.8% partially disabled, compared to 9.5% and 5.4% in UC patients (p<0.01), respectively. Compared to Dutch controls, the prevalence was significantly higher, especially in CD patients. Higher age, low education, depression, chronic back pain, joint manifestations and typical disease-related risk factors such as penetrating disease course and surgery in the past were all found to be associated with work disability. We report high work disability rates in a large sample of IBD patients in the Netherlands. CD patients suffer more frequently from work disability than UC patients. A combination of demographic and disease-related factors is predictive of work disability. Copyright © 2013 European Crohn's and Colitis Organisation. All rights reserved.

  10. Making Sense Out of Pulsating Pre-ELM and ELM White Dwarfs

    NASA Astrophysics Data System (ADS)

    Fontaine, G.; Istrate, A.; Gianninas, A.; Brassard, P.; Van Grootel, V.

    2017-03-01

    We present a unified view of pulsations in both pre-ELM and ELM white dwarfs within the framework of state-of-the-art binary evolution calculations that take into account the combined effects of diffusion and rotational mixing. We find that rotational mixing is able to maintain against settling a sufficient amount of helium in the envelope in order to fuel pulsations through He II-He III ionization on the pre-ELM branch of the evolutionary track in the spectroscopic HR diagram. By the time such a low-mass white dwarf enters the ZZ Ceti instability strip on the cooling branch, settling has taken over rotational mixing and produced a pure H envelope. Such a star then pulsates again, but, this time, as a DA white dwarf of the ZZ Ceti type.

  11. ELM studies on the COMPASS-D tokamak

    NASA Astrophysics Data System (ADS)

    Colton, A. L.; Buttery, R. J.; Fielding, S. J.; Gates, D. A.; Hender, T. C.; Hugill, J.; Morris, A. W.; Valovic, M.; COMPASS-D, the; ECRH Teams

    1996-08-01

    A description of the various ELM types observed in single null divertor plasmas in COMPASS-D is given, including type I and type III ELMs in both ECRH and ohmically heated plasmas. Precursor oscillations to both type I and type III ELMs have been observed. The large variation in the precursor mode structure is discussed, as well as models of the effect on the plasma.

  12. ELM behavior in ASDEX Upgrade with and without nitrogen seeding

    NASA Astrophysics Data System (ADS)

    Frassinetti, L.; Dunne, M. G.; Beurskens, M.; Wolfrum, E.; Bogomolov, A.; Carralero, D.; Cavedon, M.; Fischer, R.; Laggner, F. M.; McDermott, R. M.; Meyer, H.; Tardini, G.; Viezzer, E.; the EUROfusion MST1 Team; the ASDEX-Upgrade Team

    2017-02-01

    The Type I ELM behavior in ASDEX Upgrade with full W plasma facing components is studied in terms of time scales and energy losses for a large set of shots characterized by similar operational parameters but different nitrogen seeding rate and input power. ELMs with no nitrogen can have two typical behaviors, that can be classified depending on their duration, the long and the short ELMs. The work shows that both short and long ELMs have a similar first phase, but the long ELMs are characterized by a second phase with further energy losses. The second phase disappears when nitrogen is seeded with a flux rate above 1022 (e s-1). The phenomenon is compatible with a threshold effect. The presence of the second phase is related to a high divertor/scrape-off layer (SOL) temperature and/or to a low pedestal temperature. The ELM energy losses of the two phases are regulated by different mechanisms. The energy losses of the first phase increase with nitrogen which, in turn, produce the increase of the pedestal temperature. So the energy losses of the first phase are regulated by the pedestal top parameters and the increase with nitrogen is due to the decreasing pedestal collisionality. The energy losses of the second phase are related to the divertor/SOL conditions. The long ELMs energy losses increase with increasing divertor temperature and with the number of the expelled filaments. In terms of the power lost by the plasma, the nitrogen seeding increases the power losses of the short ELMs. The long ELMs have a first phase with power losses comparable to the short ELMs losses. Assuming no major difference in the wetted area, these results suggest that (i) the nitrogen might increase the divertor heat fluxes during the short ELMs and that (ii) the long ELMs, despite the longer time scale, are not beneficial in terms of divertor heat loads.

  13. Advances in understanding and utilising ELM control in JET

    NASA Astrophysics Data System (ADS)

    Chapman, I. T.; de la Luna, E.; Lang, P. T.; Liang, Y.; Alper, B.; Denner, P.; Frigione, D.; Garzotti, L.; Ham, C. J.; Huijsmans, G. T. A.; Jachmich, S.; Kocsis, G.; Lennholm, M.; Lupelli, I.; Rimini, F. G.; Sips, A. C. C.; Contributors, JET

    2016-01-01

    Edge localised mode (ELM) control may be essential to develop ITER scenarios with a reasonable lifetime of divertor components, whilst ELM pacing may be essential to develop stationary ITER scenarios with a tungsten divertor. Resonant magnetic perturbations (RMPs) have mitigated ELMs in high collisionality plasmas in JET. The efficacy of RMPs in mitigating the ELMs is found to depend on plasma shaping, with the change in magnetic boundary achieved when non-axisymmetric fields are applied facilitating access to small ELM regimes. The understanding of ELM pacing by vertical kicks or pellets has also been improved in a range of pedestal conditions in JET ({{T}\\text{ped}}=0.7 -1.3 keV) encompassing the ITER-expected domain ({β\\text{N}}=1.4 -2.4, H 98(y, 2)  =  0.8-1.2, {{f}\\text{GW}}˜ 0.7 ). ELM triggering is reliable provided the perturbation is above a threshold which depends on pedestal parameters. ELM triggering is achieved even in the first 10% of the natural ELM cycle suggesting no inherent maximum frequency. At high normalised pressure, the peeling-ballooning modes are stabilised as predicted by ELITE, necessitating a larger perturbation from either kicks or pellets in order to trigger ELMs. Both kicks and pellets have been used to pace ELMs for tungsten flushing. This has allowed stationary plasma conditions with low gas injection in plasmas where the natural ELM frequency is such that it would normally preclude stationary conditions.

  14. Adaptive Online Sequential ELM for Concept Drift Tackling

    PubMed Central

    Basaruddin, Chan

    2016-01-01

    A machine learning method needs to adapt to over time changes in the environment. Such changes are known as concept drift. In this paper, we propose concept drift tackling method as an enhancement of Online Sequential Extreme Learning Machine (OS-ELM) and Constructive Enhancement OS-ELM (CEOS-ELM) by adding adaptive capability for classification and regression problem. The scheme is named as adaptive OS-ELM (AOS-ELM). It is a single classifier scheme that works well to handle real drift, virtual drift, and hybrid drift. The AOS-ELM also works well for sudden drift and recurrent context change type. The scheme is a simple unified method implemented in simple lines of code. We evaluated AOS-ELM on regression and classification problem by using concept drift public data set (SEA and STAGGER) and other public data sets such as MNIST, USPS, and IDS. Experiments show that our method gives higher kappa value compared to the multiclassifier ELM ensemble. Even though AOS-ELM in practice does not need hidden nodes increase, we address some issues related to the increasing of the hidden nodes such as error condition and rank values. We propose taking the rank of the pseudoinverse matrix as an indicator parameter to detect “underfitting” condition. PMID:27594879

  15. Inboard and outboard observations of ELMs on EAST tokamak

    NASA Astrophysics Data System (ADS)

    Yan, Ning; Li, Jie; Xu, Sheng; Chen, Liang

    2016-10-01

    Understanding the edge-localized modes (ELMs) are considered essential for the H-mode operation such as impurity transport and safety of the first wall of future magnetic fusion devices Over last decades, important information on ELMs has been gained from a variety of diagnostics. However, the ELM behavior on high field side is still poorly understood due to less diagnostic there. Recently, two sweeping probes have been set up near inboard mid-plane of EAST tokamak, which provides a unique capability on characterizing the in-out asymmetry of ELMs together with fast reciprocating probe on outboard mid-plane. In our measurements, ELMs are manifested as propagating filaments in the outboard scrape-off layer (SOL). However plasma in the inboard SOL react as density pumping during ELM crash. Two bands of coherent fluctuations preceding ELMs are observed at outboard mid-plane. They are propagating in opposite poloidal direction in the plasma frame The fluctuations saturate before ELM crash, and their frequency alter with pedestal pressure The coherence of higher frequency band fluctuations are significantly reduced on high field side, and plasma appear as broad turbulence instead. These findings can potentially improve our understanding on ELM dynamics.

  16. Patterns of Hybridization and Introgression Between Invasive Ulmus Pumila (Ulmaceae) and Native U. Rubra

    USDA-ARS?s Scientific Manuscript database

    Ulmus pumila (Siberian elm) is an invasive elm species, non-native to the United States, which hybridizes with Ulmus rubra (red elm), a U.S. native. While Siberian elm is highly tolerant to Dutch elm disease (DED), red elm populations in North America have been strongly affected by DED. Putative p...

  17. A concept for a decision support system based on practical experiences from a national disease emergency. The Dutch experience.

    PubMed

    Crauwels, A P; de Koning, R; Nielen, M; Elbers, A R; Dijkhuizen, A A; Tielen, M J

    2001-01-01

    In 1997-1998, the Netherlands experienced a large epidemic of classical swine fever (CSF). The magnitude of this epidemic stressed the role information systems could play in supporting the management during an eradication campaign. The enforcement of an eradication strategy can become very complicated, especially with large epidemics, due to time pressure and many different procedures that have to be executed at the same time. The application of comprehensive information systems may result in more control over the process and in a relief of the operational management. After a brief description of the Dutch epidemic the authors provide an overview and the general application of four different types of information systems, classified as decision support systems. The application of these information systems in animal disease control is illustrated by providing concepts for a system architecture for transaction processing, management and executive information support and decision support. The application of a data warehouse as part of this systems architecture is explained. The eradication of CSF from the Netherlands was complicated by several factors. It is important to notice that information systems cannot prevent these factors. However, information systems can support disease control authorities in controlling these factors.

  18. 'A necessary evil that does not "really" cure disease': The domestication of biomedicine by Dutch holistic general practitioners.

    PubMed

    Raaphorst, Nadine; Houtman, Dick

    2016-05-01

    Against the background of studies about the domestication of complementary and alternative medicine into biomedical settings, this article studies how biomedicine is integrated into holistic settings. Data from 19 in-depth interviews with Dutch holistic general practitioners who combine complementary and alternative medicine with conventional treatments demonstrate that they do not believe that conventional biomedicine 'really' cures patients. They feel that it merely suppresses the physical symptoms of a disease, leaving the more fundamental and non-physical causes intact. As a consequence, they use conventional biomedicine for strictly practical and instrumental reasons. This is the case in life-threatening or acute situations, understood as non-physical causes of disease having been left untreated with complementary and alternative medicine for too long. More mundane reasons for its use are the need to take patients' demands for biomedical treatment seriously or to obey authoritative rules, regulations and protocols. The integration of biomedicine into complementary and alternative medicine, then, follows the same logic of domestication of complementary and alternative medicine into biomedicine: it is made subordinate to the prevailing model of health and illness and treated as a practical add-on that does not 'really' cure people.

  19. Rabies in the Dutch East Indies a century ago - a spatio-temporal case study in disease emergence.

    PubMed

    Ward, Michael P

    2014-04-01

    Rabies continues to spread through the Indonesian archipelago. During the past 20 years, several islands - including Flores, Ambon and Bali - that had historically been free of rabies have become infected. However, the Dutch East Indies (a Dutch colony that became modern Indonesia following World War II) had been infected since the 1880s. The spread of rabies is a lesson in the emergence of an infectious disease. Reports of human cases treated for rabies and livestock rabies cases from the 1880s to 1917 were compiled. The spatial and temporal distribution of these cases was analyzed using maps, spatial statistics and time-series techniques. The first confirmed case of rabies was reported in 1889 from the Batavia [Jakarta] district (although disease suspicion was reported as early as 1884). During the 1890s rabies was already commonly reported from Java and the east coast of Sumatra, and by the late 1890s, from Celebes [Sulawesi]. Between 1900 and 1916, cases were reported from other parts of Java, Sumatra and Sulawesi, and from Borneo, the Moluccas and other outlying islands. Between 1897 and 1916, a total of 8826 human cases treated for rabies were reported and between 1908 and 1917, 1033 livestock cases were reported. Most (97.5%) human cases treated were attributed to rabid dogs. Increasing numbers of reports were observed during the period. Between 1908 and 1916 the correlation between human and livestock case reports was 64.2%, and at the district level it was 75.9%. Moderate correlations (>40%) were found between human cases and livestock cases reported up to six months previously. Based on year of first report from each district, human cases were strongly clustered (Moran's autocorrelation 0.47, P=0.005). The most likely spatio-temporal cluster of reported cases of humans treated for rabies originated from the west coast of Sumatra between 1899 and 1905, and other clusters were identified in west Java (1898-1899), the district of Batavia and in east Java

  20. Investigation of ELMs on Alcator C-Mod

    NASA Astrophysics Data System (ADS)

    Terry, J. L.

    2005-10-01

    C-Mod typically operates in regimes without large ELMs. Recently, discrete ELMs have been routinely produced by making plasmas with large lower triangularity (i.e. >0.75), compared to the more typical C-Mod values <0.6. The ELM character was substantially modified as the triangularity was reduced, changing from discrete ELMs of ˜60 μsec duration, to H-to-L mode back transitions, lasting ˜4msec. The discrete ELMs are most apparent when the density is just above the low-density H-mode threshold, ne˜8x10^19m-3. Pedestal Te up to 1 keV was measured early in the H-mode phase. The spatial structure and propagation of the discrete ELMs are studied using fast-framing (˜250 kHz) cameras and other high resolution optical diagnostics. The magnetics and the optical diagnostics show a rapidly-growing precursor oscillation (100-200 kHz just prior to the ELM crash) that is localized radially to around the top of the pedestal. Outside the LCFS the enhanced emission from the ELM propagates radially outward with a complicated spatial structure, similar in many respects to `blobs.'

  1. Establishment patterns of water-elm at Catahoula Lake, Louisiana

    Treesearch

    Karen S. Doerr; Sanjeev Joshi; Richard F. Keim

    2015-01-01

    At Catahoula Lake in central Louisiana, an internationally important lake for water fowl, hydrologic alterations to the surrounding rivers and the lake itself have led to an expansion of water-elm (Planera aquatic J.F. Gmel.) into the lake bed. In this study, we used dendrochronology and aerial photography to quantify the expansion of water-elm in the lake and identify...

  2. [The Dutch College of General Practitioners' practice guideline 'Parkinson's disease' in summary].

    PubMed

    Draijer, Willem; Eizenga, Wietze H; Sluiter, Alja; Opstelten, Wim; Goudswaard, A N Lex

    2011-01-01

    Parkinson's disease is characterised by bradykinesia in combination with one or more of the following symptoms: rigidity, resting tremor and disorders of posture and balance. Refer a patient with suspected Parkinson's disease (or parkinsonism) for diagnosis and treatment preferably to a neurologist with expertise in movement disorders. The treatment of Parkinson's disease is symptomatic; to date, there is no treatment that slows disease progression. The treatment of patients with Parkinson's disease and its related disorders involves collaboration of the neurologist, Parkinson's disease nurse and general practitioner. In addition to recognizing the hypokinetic-rigid syndrome, the general practitioner has a role in diagnosing and treating associated symptoms and disorders, and in supporting and counseling the patient and their partner or caregiver.

  3. ELM filament interaction with the JET main chamber

    NASA Astrophysics Data System (ADS)

    Jakubowski, M. W.; Fundamenski, W.; Arnoux, G.; Eich, Th.; Pitts, R. A.; Reiter, D.; Wolf, R. C.; JET-EFDA contributors

    2009-06-01

    This work constitutes the first extended analysis of the spatial structure of Type-I ELM filament footprints on the JET outer limiters and upper dump plates. The data is obtained using a wide angle infrared diagnostic (with time resolution of 125 Hz) and concerns ELMs with energy in the range 0.07⩽ΔW/W⩽0.32. Type-III ELM filaments are not observed to deposit significant heat loads. The typical poloidal width of an ELM filament footprint is of order of 4-10° on the outer limiters and of order of 1-4° on the upper dump plates with weak linear dependence on the ELM size. Their quasi-toroidal mode numbers are in the range of 30-60 and 20-30, respectively.

  4. Evaluation of a large scale implementation of disease management programmes in various Dutch regions: a study protocol.

    PubMed

    Lemmens, Karin M M; Rutten-Van Mölken, Maureen P M H; Cramm, Jane M; Huijsman, Robbert; Bal, Roland A; Nieboer, Anna P

    2011-01-10

    Disease management programmes (DMPs) have been developed to improve effectiveness and economic efficiency within chronic care delivery by combining patient-related, professional-directed, and organisational interventions. The benefits of DMPs within different settings, patient groups, and versions remain unclear. In this article we propose a protocol to evaluate a range of current DMPs by capturing them in a single conceptual framework, employing comparable structure, process, and outcome measures, and combining qualitative and quantitative research methods. To assess DMP effectiveness a practical clinical trial will be conducted. Twenty-two disease management experiments will be studied in various Dutch regions consisting of a variety of collaborations between organisations and/or professionals. Patient cohorts include those with cardiovascular diseases, chronic obstructive pulmonary disease, diabetes, stroke, depression, psychotic diseases, and eating disorders. Our methodological approach combines qualitative and quantitative research methods to enable a comprehensive evaluation of complex programmes. Process indicators will be collected from health care providers' data registries and measured via physician and staff questionnaires. Patient questionnaires include health care experiences, health care utilisation, and quality of life. Qualitative data will be gathered by means of interviews and document analysis for an in depth description of project interventions and the contexts in which DMPs are embedded, and an ethnographic process evaluation in five DMPs. Such a design will provide insight into ongoing DMPs and demonstrate which elements of the intervention are potentially (cost)-effective for which patient populations. It will also enable sound comparison of the results of the different programmes. The study will lead to a better understanding of (1) the mechanisms of disease management, (2) the feasibility, and cost-effectiveness of a disease management

  5. Evaluation of a large scale implementation of disease management programmes in various Dutch regions: a study protocol

    PubMed Central

    2011-01-01

    Background Disease management programmes (DMPs) have been developed to improve effectiveness and economic efficiency within chronic care delivery by combining patient-related, professional-directed, and organisational interventions. The benefits of DMPs within different settings, patient groups, and versions remain unclear. In this article we propose a protocol to evaluate a range of current DMPs by capturing them in a single conceptual framework, employing comparable structure, process, and outcome measures, and combining qualitative and quantitative research methods. Methods To assess DMP effectiveness a practical clinical trial will be conducted. Twenty-two disease management experiments will be studied in various Dutch regions consisting of a variety of collaborations between organisations and/or professionals. Patient cohorts include those with cardiovascular diseases, chronic obstructive pulmonary disease, diabetes, stroke, depression, psychotic diseases, and eating disorders. Our methodological approach combines qualitative and quantitative research methods to enable a comprehensive evaluation of complex programmes. Process indicators will be collected from health care providers' data registries and measured via physician and staff questionnaires. Patient questionnaires include health care experiences, health care utilisation, and quality of life. Qualitative data will be gathered by means of interviews and document analysis for an in depth description of project interventions and the contexts in which DMPs are embedded, and an ethnographic process evaluation in five DMPs. Such a design will provide insight into ongoing DMPs and demonstrate which elements of the intervention are potentially (cost)-effective for which patient populations. It will also enable sound comparison of the results of the different programmes. Discussion The study will lead to a better understanding of (1) the mechanisms of disease management, (2) the feasibility, and cost

  6. Spoken Dutch.

    ERIC Educational Resources Information Center

    Bloomfield, Leonard

    This course in spoken Dutch is intended for use in introductory conversational classes. The book is divided into five major parts, each containing five learning units and one unit devoted to review. Each unit contains sections including (1) basic sentences, (2) word study and review of basic sentences, (3) listening comprehension, and (4)…

  7. Model of ELM suppression by RMPs in DIII-D

    NASA Astrophysics Data System (ADS)

    Callen, J. D.; Nazikian, R.; Ferraro, N. M.; Beidler, M. T.; Hegna, C. C.; La Haye, R. J.; Paz-Soldan, C.

    2016-10-01

    Recent DIII-D experiments explored effects of resonant magnetic perturbations (RMPs) near the minimum applied n=2 RMP amplitude required for ELM suppression in ITER-relevant low collisionality pedestals. Comprehensive tokamak forced magnetic reconnection (FMR) theory is used to describe and quantify the many physical processes involved in stages of RMP effects and an ELM crash response that lead to bifurcation into an ELM-suppressed state: 1) in ELMing equilibrium, flow-screening is strong with little magnetic reconnection; 2) the RMP at q=8/2 penetrates via FMR induced by an ELM crash and locks toroidal flow to the lab frame (like error field mode locking); 3) the ELM crash provides a 8/2 seed island (like NTMs) governed by a modified Rutherford equation; 4) if the total 8/2 RMP is large enough the internal tearing response and flow bifurcate and grow; and 5) flutter transport reduces pedestal top gradients which stabilizes P-B modes and hence suppresses ELMs. This analysis is for discharge 158115 in DIII-D; its potential universality is yet to be determined. Work supported by OFES/DOE under DE-FG02-92ER54139, DE-FG02-86ER53218, DE-AC02-09CH11466 and DE-FC02-04ER54698.

  8. The ELM Survey. VI. Eleven New Double Degenerates

    NASA Astrophysics Data System (ADS)

    Gianninas, A.; Kilic, Mukremin; Brown, Warren R.; Canton, Paul; Kenyon, Scott J.

    2015-10-01

    We present the discovery of 11 new double degenerate systems containing extremely low-mass white dwarfs (ELM WDs). Our radial velocity observations confirm that all of the targets have orbital periods ≤slant 1 day. We perform spectroscopic fits and provide a complete set of physical and binary parameters. We review and compare recent evolutionary calculations and estimate that the systematic uncertainty in our mass determinations due to differences in the evolutionary models is small (≈ 0.01 M⊙). Five of the new systems will merge due to gravitational wave radiation within a Hubble time, bringing the total number of merger systems found in the ELM Survey to 38. We examine the ensemble properties of the current sample of ELM WD binaries, including the period distribution as a function of effective temperature, and the implications for the future evolution of these systems. We also revisit the empirical boundaries of instability strip of ELM WDs and identify new pulsating ELM WD candidates. Finally, we consider the kinematic properties of our sample of ELM WDs and estimate that a significant fraction of the WDs from the ELM Survey are members of the Galactic halo. Based on observations obtained at the MMT Observatory, a joint facility of the Smithsonian Institution and the University of Arizona.

  9. Relational coordination promotes quality of chronic care delivery in Dutch disease-management programs.

    PubMed

    Cramm, Jane Murray; Nieboer, Anna Petra

    2012-01-01

    Previous studies have shown that relational coordination is positively associated with the delivery of hospital care, acute care, emergency care, trauma care, and nursing home care. The effect of relational coordination in primary care settings, such as disease-management programs, remains unknown. This study examined relational coordination between general practitioners and other professionals in disease-management programs and assessed the impact of relational coordination on the delivery of chronic illness care. Professionals (n = 188; response rate = 57%) in 19 disease-management programs located throughout the Netherlands completed surveys that assessed relational coordination and chronic care delivery. We used a cross-sectional study design. Our study demonstrated that the delivery of chronic illness care was positively related to relational coordination. We found positive relationships with community linkages (r = .210, p < .01), self-management support (r = .217, p < .01), decision support (r = .190, p < .01), delivery system design (r = .278, p < .001), and clinical information systems (r = .193, p < .01). Organization of the health delivery system was not significantly related to relational coordination. The regression analyses showed that even after controlling for all background variables, relational coordination still significantly affected chronic care delivery (β = .212, p ≤ .01). As expected, our findings showed a lower degree of relational coordination among general practitioners than between general practitioners and other core disease-management team members: practice nurses (M = 2.69 vs. 3.73; p < .001), dieticians (M = 2.69 vs. 3.07; p < .01), physical therapists (M = 2.69 vs. 3.06; p < .01), medical specialists (M = 2.69 vs. 3.16; p < .01), and nurse practitioners (M = 2.69 vs. 3.19; p < .001). The enhancement of relational coordination among core disease-management professionals with different disciplines is expected to improve chronic

  10. ELM transport in the JET scrape-off layer

    NASA Astrophysics Data System (ADS)

    Pitts, R. A.; Andrew, P.; Arnoux, G.; Eich, T.; Fundamenski, W.; Huber, A.; Silva, C.; Tskhakaya, D.; EFDA Contributors, JET

    2007-11-01

    This contribution summarizes a number of aspects of the experimental and modelling programme at JET aimed at improving the characterization and understanding of edge localized mode (ELM) transport in the scrape-off layer (SOL). Divertor target energy deposition asymmetries favouring the inner target for the ion B × ∇B drift directed towards the X-point are observed with infra-red (IR) thermography. Similar trends are seen in the ELM resolved energy radiated in the divertor volume. Particle-in-cell kinetic calculations of the parallel ELM heat transport have been made for a range of ELM energies, revealing the detailed time response of target sheath heat transmission factors and indicating that electrons deposit ~30% of the ELM energy. The simulation results are in good agreement with experimental measurements of the integral energy deposited at the outer target up to the peak in target heat loads. A transient model of ELM filament energy evolution has been developed at JET and is able to reproduce a number of experimental observations, including the high ion energies observed in the far SOL using an electrostatic retarding field electrostatic analyser (RFA) and estimates of ELM heat fluxes deposited on main chamber limiters. During the ELM, the RFA and a second, SOL turbulence probe, clearly show the presence of coherent spikes in the hot ion flux, the plasma flux and the electron temperature. Field aligned structures have also been seen for the first time on JET in the power deposition on main wall limiters and upper dump plate surfaces using a new wide angle IR camera system. The probe signals are interpreted as the arrival of interspaced plasma filaments, with successive filaments carrying less energy. They are also consistent with the ELM out flux entering the SOL primarily on the outboard side and launching a sound wave disturbance along field lines.

  11. First Observation Of ELM Pacing With Vertical Jogs In A Spherical Torus

    SciTech Connect

    Gerhardt, S P; Canik, J M; Maingi, R; Bell, R; Gates, d; Goldston, R; Hawryluk, R; Le Blanc, B P; Menard, J; Sontag, A C; Sabbagh, S

    2010-07-15

    Experiments in a number of conventional aspect ratio tokamaks have been successful in pacing edge localized modes (ELMs) by rapid vertical jogging of the plasma. This paper demonstrates the first pacing of ELMs in a spherical torus plasma. Applied 30 Hz vertical jogs synchronized the ELMs with the upward motion of the plasma. 45 Hz jogs also lead to an increase in the ELM frequency, though the synchronization of the ELMs and jogs was unclear. A reduction in the ELM energy was observed at the higher driven ELM frequencies. __________________________________________________

  12. Development and validation of a short version of the Assessment of Chronic Illness Care (ACIC) in Dutch disease management programs.

    PubMed

    Cramm, Jane M; Strating, Mathilde M H; Tsiachristas, Apostolos; Nieboer, Anna P

    2011-07-04

    In the Netherlands the extent to which chronically ill patients receive care congruent with the Chronic Care Model is unknown. The main objectives of this study were to (1) validate the Assessment of Chronic Illness Care (ACIC) in the Netherlands in various Disease Management Programmes (DMPs) and (2) shorten the 34-item ACIC while maintaining adequate validity, reliability, and sensitivity to change. The Dutch version of the ACIC was tested in 22 DMPs with 218 professionals. We tested the instrument by means of structural equation modelling, and examined its validity, reliability and sensitivity to change. After eliminating 13 items, the confirmatory factor analyses revealed good indices of fit with the resulting 21-item ACIC (ACIC-S). Internal consistency as represented by Cronbach's alpha ranged from 'acceptable' for the 'clinical information systems' subscale to 'excellent' for the 'organization of the healthcare delivery system' subscale. Correlations between the ACIC and ACIC-S subscales were also good, ranging from .87 to 1.00, indicating acceptable coverage of the core areas of the CCM. The seven subscales were significantly and positively correlated, indicating that the subscales were conceptually related but also distinct. Paired t-tests results show that the ACIC scores of the original instrument all improved significantly over time in regions that were in the process of implementing DMPs (all components at p < 0.0001). We conclude that the psychometric properties of the ACIC and the ACIC-S are good and the ACIC-S is a promising alternate instrument to assess chronic illness care.

  13. Sexual behaviour and sexually transmitted diseases in Dutch marines and naval personnel on a United Nations mission in Cambodia.

    PubMed Central

    Hopperus Buma, A P; Veltink, R L; van Ameijden, E J; Tendeloo, C H; Coutinho, R A

    1995-01-01

    OBJECTIVES--To determine the sexual risk behaviour and the incidence of sexually transmitted diseases (STD) among Dutch marines and naval personnel during a United Nations (UN) deployment. METHODS--Surveillance by post deployment questionnaire, administered to 2289 persons in three successive battalions who served for 6 months on a UN deployment in Cambodia during June 1992-November 1993. On site the medical history of all individuals was kept up to date in a database. All personnel received extra education on STD prevention prior to deployment. Condoms were freely obtainable during deployment. RESULTS--1885 persons (82%) handed in the questionnaire of whom 842 (45%) reported to have had sexual contacts with prostitutes or local population. Being younger and single were independent risk factors for having contact. Out of these 842 persons, 750 (89.1%) reported condom use at all times, while 82 (9.7%) reported inconsistent use and 10 persons (1.2%) reported not to have used condoms. Risk factors for inconsistent and non use were being 40 years or older and a higher number of contacts. From the 832 (750 + 82) condom users, 248 (30%) reported condom failure. Risk factors for failure were: inconsistent condom use, having had more than six contacts and being in the second battalion. The patient recording database showed 43 STD cases registered in the total population of 2289 persons (1.9%). CONCLUSIONS--A low STD incidence was found despite a considerable number of reported sexual contacts. The reported condom use was high but the failure rate was considerable and needs further attention. PMID:7635494

  14. Development and validation of a short version of the Assessment of Chronic Illness Care (ACIC) in Dutch Disease Management Programs

    PubMed Central

    2011-01-01

    Background In the Netherlands the extent to which chronically ill patients receive care congruent with the Chronic Care Model is unknown. The main objectives of this study were to (1) validate the Assessment of Chronic Illness Care (ACIC) in the Netherlands in various Disease Management Programmes (DMPs) and (2) shorten the 34-item ACIC while maintaining adequate validity, reliability, and sensitivity to change. Methods The Dutch version of the ACIC was tested in 22 DMPs with 218 professionals. We tested the instrument by means of structural equation modelling, and examined its validity, reliability and sensitivity to change. Results After eliminating 13 items, the confirmatory factor analyses revealed good indices of fit with the resulting 21-item ACIC (ACIC-S). Internal consistency as represented by Cronbach's alpha ranged from 'acceptable' for the 'clinical information systems' subscale to 'excellent' for the 'organization of the healthcare delivery system' subscale. Correlations between the ACIC and ACIC-S subscales were also good, ranging from .87 to 1.00, indicating acceptable coverage of the core areas of the CCM. The seven subscales were significantly and positively correlated, indicating that the subscales were conceptually related but also distinct. Paired t-tests results show that the ACIC scores of the original instrument all improved significantly over time in regions that were in the process of implementing DMPs (all components at p < 0.0001). Conclusion We conclude that the psychometric properties of the ACIC and the ACIC-S are good and the ACIC-S is a promising alternate instrument to assess chronic illness care. PMID:21726439

  15. Relationships between fatty liver and fertility and some periparturient diseases in commercial Dutch dairy herds.

    PubMed

    Jorritsma, R; Jorritsma, H; Schukken, Y H; Wentink, G H

    2000-10-15

    Declining fertility in dairy cows is frequently suggested to arise from the occurrence of a more negative energy balance and/or the concomitant increased accumulation of triacylglycerol in the liver. Therefore, we performed a field study to assess the clinical effects of postpartum fatty liver in dairy cows on fertility and reproductive disease. Data were collected from 360 cows from nine dairy herds on fertility, diseases, and the liver triacylglycerol content on two occasions during lactation: 6 to 17 days and 38 to 50 days postpartum. The mean concentration of triacylglycerol in the liver was 54.6 mg/g from 6 to 17 days and 38.4 mg/g from 38 to 50 days postpartum. The probability of pregnancy was 30% lower for cows with higher contents of triacylglycerol in the liver compared to the probability for cows with low liver triacylglycerol (P = 0.049). The probability of estrus was also 35% lower for the cows with high triacylglycerol in the liver. This resulted in larger intervals between parturition and first heat and parturition and pregnancy for these cows. There was no effect observed on the first insemination conception rate. Given a certain level of triacylglycerol, recorded milk production had a positive effect on time to pregnancy. The incidences of endometritis, lochiometra and cystic ovarian follicles were not higher in cows with higher liver triacylglycerol contents. Endometritis was associated with a lower first insemination conception rate and more days open (chi2 = 4.26, P = 0.03 and T-test = -2.02, P= 0.04 respectively). We concluded that our results support the idea that differences in the negative energy balance or the accumulation of triacylglycerol in the liver of postpartum dairy cows affect fertility performance. The data also indicate that an increase in milk production has no negative impact on fertility as long as the amount of triacylglycerol in the liver remains the same.

  16. Revisiting the Dutch hypothesis.

    PubMed

    Postma, Dirkje S; Weiss, Scott T; van den Berge, Maarten; Kerstjens, Huib A M; Koppelman, Gerard H

    2015-09-01

    The Dutch hypothesis was first articulated in 1961, when many novel and advanced scientific techniques were not available, such as genomics techniques for pinpointing genes, gene expression, lipid and protein profiles, and the microbiome. In addition, computed tomographic scans and advanced analysis techniques to dissect (small) airways disease and emphysema were not available. At that time, the group of researchers under the visionary guidance of Professor N. G. M. Orie put forward that both genetic and environmental factors can determine whether one would have airway obstructive diseases, such as asthma and chronic obstructive pulmonary disease (COPD). Moreover, they stipulated that the phenotype of obstructive airway disease could be affected by sex and changes with aging. Orie and colleagues' call to carefully phenotype patients with obstructive airways diseases has been adopted by many current researchers in an attempt to determine the heterogeneity of both asthma and COPD to better define these diseases and optimize their treatment. The founders of the Dutch hypothesis were far ahead of their time, and we can learn from their insights. We should fully characterize all patients in our clinical practice and not just state that they have asthma, COPD, or asthma and COPD overlap syndrome. This detailed phenotyping can help in understanding these obstructive airway diseases and provide guidance for disease management.

  17. Pheromone Chemistry of the Smaller European Elm Bark Beetle.

    ERIC Educational Resources Information Center

    Beck, Keith

    1978-01-01

    Discusses the aggregation pheromone of the smaller European elm bark beetle, Scolytus multistriatus (Marsham), with emphasis on information that could be used in the classroom as a practical application of organic chemistry. (Author/GA)

  18. VIEW OF ELM DRIVE WITH FACILITY 708 ON LEFT. VIEW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF ELM DRIVE WITH FACILITY 708 ON LEFT. VIEW FACING EAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  19. VIEW OF ELM DRIVE WITH NORFOLK PINE ON RIGHT. VIEW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF ELM DRIVE WITH NORFOLK PINE ON RIGHT. VIEW FACING WEST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  20. Comparison of ELM heat loads in snowflake and standard divertors

    SciTech Connect

    Rognlien, T D; Cohen, R H; Ryutov, D D; Umansky, M V

    2012-05-08

    An analysis is given of the impact of the tokamak divertor magnetic structure on the temporal and spatial divertor heat flux from edge localized modes (ELMs). Two configurations are studied: the standard divertor where the poloidal magnetic field (B{sub p}) varies linearly with distance (r) from the magnetic null and the snowflake where B{sub p} varies quadratrically with r. Both one and two-dimensional models are used to analyze the effect of the longer magnetic field length between the midplane and the divertor plate for the snowflake that causes a temporal dilation of the ELM divertor heat flux. A second effect discussed is the appearance of a broad region near the null point where the poloidal plasma beta can substantially exceed unity, especially for the snowflake configuration during the ELM; such a condition is likely to drive additional radial ELM transport.

  1. 46. VIEW LOOKING EAST FROM THE OLMSTED ELM IN THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    46. VIEW LOOKING EAST FROM THE OLMSTED ELM IN THE SOUTH LAWN TO THE ROCK GARDEN. (NOTE: HISTORIC ENGLISH YEW ON RIGHT, CRAB APPLE IN CENTER VIEW). - Fairsted, 99 Warren Street, Brookline, Norfolk County, MA

  2. Pheromone Chemistry of the Smaller European Elm Bark Beetle.

    ERIC Educational Resources Information Center

    Beck, Keith

    1978-01-01

    Discusses the aggregation pheromone of the smaller European elm bark beetle, Scolytus multistriatus (Marsham), with emphasis on information that could be used in the classroom as a practical application of organic chemistry. (Author/GA)

  3. ELM induced tungsten melting and its impact on tokamak operation

    NASA Astrophysics Data System (ADS)

    Coenen, J. W.; Arnoux, G.; Bazylev, B.; Matthews, G. F.; Jachmich, S.; Balboa, I.; Clever, M.; Dejarnac, R.; Coffey, I.; Corre, Y.; Devaux, S.; Frassinetti, L.; Gauthier, E.; Horacek, J.; Knaup, M.; Komm, M.; Krieger, K.; Marsen, S.; Meigs, A.; Mertens, Ph.; Pitts, R. A.; Puetterich, T.; Rack, M.; Stamp, M.; Sergienko, G.; Tamain, P.; Thompson, V.

    2015-08-01

    In JET-ILW dedicated melt exposures were performed using a sequence of 3MA/2.9T H-Mode JET pulses with an input power of PIN = 23 MW, a stored energy of ∼6 MJ and regular type I ELMs at ΔWELM = 0.3 MJ and fELM ∼ 30 Hz. In order to assess the risk of starting ITER operations with a full W divertor, one of the task was to measure the consequences of W transients melting due to ELMs. JET is the only tokamak able to produce transients/ ELMs large enough (>300 kJ per ELM) to facilitate melting of tungsten. Such ELMs are comparable to mitigated ELMs expected in ITER. By moving the outer strike point (OSP) onto a dedicated leading edge the base temperature was raised within ∼1 s to allow transient ELM-driven melting during the subsequent 0.5 s. Almost 1 mm (∼6 mm3) of W was moved by ∼ 150 ELMs within 5 subsequent discharges. Significant material losses in terms of ejections into the plasma were not observed. There is indirect evidence that some small droplets (∼ 80 μm) were ejected. The impact on the main plasma parameters is minor and no disruptions occurred. The W-melt gradually moved along the lamella edge towards the high field side, driven by j × B forces. The evaporation rate determined is 100 times less than expected from steady state melting and thus only consistent with transient melting during individual ELMs. IR data, spectroscopy, as well as melt modeling point to transient melting. Although the type of damage studied in these JET experiments is unlikely to be experienced in ITER, the results do strongly support the design strategy to avoid exposed edges in the ITER divertor. The JET experiments required a surface at normal incidence and considerable pre-heating to produce tungsten melting. They provide unique experimental evidence for the absence of significant melt splashing at events resembling mitigated ELMs on ITER and establish a unique experimental benchmark for the simulations being used to study transient shallow melting on ITER W

  4. The impact of peeling-ballooning turbulence on ELMs

    NASA Astrophysics Data System (ADS)

    Xi, Pengwei

    2013-10-01

    Although the onset of ELMs has possibly been determined by linear peeling-ballooning (P-B) instabilities and, the nonlinear BOUT + + simulations show that nonlinear mode coupling starts before the onset of ELMs, which can lead to finite amplitude peeling-ballooning (P-B) turbulence at the H-mode pedestal and play a crucial role in ELM dynamics in two aspects: (1) since the P-B turbulence can suppress ELM crash, for a given power input, pedestal can keep evolving to a state with larger pedestal pressure and current gradients. Accordingly, the drives of P-B modes also keep increasing. Therefore the onset of ELM is determined by the competition between linear drive and nonlinear mode coupling. We find that only when a single mode can overcome the nonlinear damping to become dominant, an ELM crash is triggered by this mode. This means with the P-B turbulence, the onset of ELM is determined by a nonlinear criterion γ >γc rather than the previous linear criterion γ > 0 , where γc is the critical growth rate which depends on the P-B turbulence. (2) We find that the P-B turbulence can generate enough self-constant hyper-resistivity needed in ELM simulations when electron inertial is included in Ohm's law. This hyper-resistivity represents anomalous current transport and can set the limit of the narrow current layer width resolved in the simulations. Except the P-B turbulence, the impact of other micro-turbulence, such as KBM turbulence, will be presented via a newly developed electro-magnetic Gyro-Landau-Fluid extension of BOUT + + code. Work was performed for USDOE by LLNL under DE-AC52-07NA27344, LLNL LDRD project 12-ERD-022, and also supported by the NSFC under Grant Nos.10935004, 11261140326.

  5. A genomewide screen for late-onset Alzheimer disease in a genetically isolated Dutch population.

    PubMed

    Liu, Fan; Arias-Vásquez, Alejandro; Sleegers, Kristel; Aulchenko, Yurii S; Kayser, Manfred; Sanchez-Juan, Pascual; Feng, Bing-Jian; Bertoli-Avella, Aida M; van Swieten, John; Axenovich, Tatiana I; Heutink, Peter; van Broeckhoven, Christine; Oostra, Ben A; van Duijn, Cornelia M

    2007-07-01

    Alzheimer disease (AD) is the most common cause of dementia. We conducted a genome screen of 103 patients with late-onset AD who were ascertained as part of the Genetic Research in Isolated Populations (GRIP) program that is conducted in a recently isolated population from the southwestern area of The Netherlands. All patients and their 170 closely related relatives were genotyped using 402 microsatellite markers. Extensive genealogy information was collected, which resulted in an extremely large and complex pedigree of 4,645 members. The pedigree was split into 35 subpedigrees, to reduce the computational burden of linkage analysis. Simulations aiming to evaluate the effect of pedigree splitting on false-positive probabilities showed that a LOD score of 3.64 corresponds to 5% genomewide type I error. Multipoint analysis revealed four significant and one suggestive linkage peaks. The strongest evidence of linkage was found for chromosome 1q21 (heterogeneity LOD [HLOD]=5.20 at marker D1S498). Approximately 30 cM upstream of this locus, we found another peak at 1q25 (HLOD=4.0 at marker D1S218). These two loci are in a previously established linkage region. We also confirmed the AD locus at 10q22-24 (HLOD=4.15 at marker D10S185). There was significant evidence of linkage of AD to chromosome 3q22-24 (HLOD=4.44 at marker D3S1569). For chromosome 11q24-25, there was suggestive evidence of linkage (HLOD=3.29 at marker D11S1320). We next tested for association between cognitive function and 4,173 single-nucleotide polymorphisms in the linked regions in an independent sample consisting of 197 individuals from the GRIP region. After adjusting for multiple testing, we were able to detect significant associations for cognitive function in four of five AD-linked regions, including the new region on chromosome 3q22-24 and regions 1q25, 10q22-24, and 11q25. With use of cognitive function as an endophenotype of AD, our study indicates the that the RGSL2, RALGPS2, and C1orf49 genes

  6. Occupational exposures and Parkinson's disease mortality in a prospective Dutch cohort.

    PubMed

    Brouwer, Maartje; Koeman, Tom; van den Brandt, Piet A; Kromhout, Hans; Schouten, Leo J; Peters, Susan; Huss, Anke; Vermeulen, Roel

    2015-06-01

    We investigated the association between six occupational exposures (ie, pesticides, solvents, metals, diesel motor emissions (DME), extremely low frequency magnetic fields (ELF-MF) and electric shocks) and Parkinson's disease (PD) mortality in a large population-based prospective cohort study. The Netherlands Cohort Study on diet and cancer enrolled 58,279 men and 62,573 women aged 55-69 years in 1986. Participants were followed up for cause-specific mortality over 17.3 years, until December 2003, resulting in 402 male and 207 female PD deaths. Following a case-cohort design, a subcohort of 5,000 participants was randomly sampled from the complete cohort. Information on occupational history and potential confounders was collected at baseline. Job-exposure matrices were applied to assign occupational exposures. Associations with PD mortality were evaluated using Cox regression. Among men, elevated HRs were observed for exposure to pesticides (eg, ever high exposed, HR 1.27, 95% CI 0.86 to 1.88) and ever high exposed to ELF-MF (HR 1.54, 95% CI 1.00 to 2.36). No association with exposure duration or trend in cumulative exposure was observed for any of the occupational exposures. Results among women were unstable due to small numbers of high-exposed women. Associations with PD mortality were observed for occupational exposure to pesticides and ELF-MF. However, the weight given to these findings is limited by the absence of a monotonic trend with either duration or cumulative exposure. No associations were found between PD mortality and occupational exposure to solvents, metals, DME or electric shocks. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  7. ['Variant of Creutzfeldt-Jacob disease and blood transfusion'; report of the Dutch Health Council].

    PubMed

    van Aken, W G

    2001-07-28

    The new variant form of Creutzfeldt-Jakob Disease (vCJD), which has been diagnosed in about 100 patients--mostly in the United Kingdom (UK)--is considered to be associated with the consumption of beef contaminated with the agent bovine spongi-form encephalopathy (BSE). Although no cases of vCJD have been reported until now in the Netherlands, large quantities of beef have been imported from the UK in previous years; furthermore about 17 cattle with BSE have been detected in the Netherlands. Concern about the possible transmission of vCJD via blood and blood-products has led to a number of countries taking precautionary measures. Following questions raised by the Minister of Health, Welfare and Sport, the Health Council of the Netherlands issued a report to address the need for certain precautionary measures such as the leukodepletion of blood and the exclusion of donors at risk for vCJD. The Health Council recommends the routine leukodepletion of cellular blood components. The exclusion of donors who have resided in the UK for six or more months during the period 1980-1996, was considered to be insufficient to contribute to risk reduction. The Minister has recently decided to follow these two recommendations. However, she is of the opinion that the Health Council's recommendation to exclude all donors who have previously been transfused with cellular blood components is unnecessary. A common European position regarding such precautionary measures is deemed to be necessary. This would allow the exchange of blood components between countries and would also prevent donors, patients and the public at large from being confused or uncertain about the safety of blood components.

  8. Long-term time series prediction using OP-ELM.

    PubMed

    Grigorievskiy, Alexander; Miche, Yoan; Ventelä, Anne-Mari; Séverin, Eric; Lendasse, Amaury

    2014-03-01

    In this paper, an Optimally Pruned Extreme Learning Machine (OP-ELM) is applied to the problem of long-term time series prediction. Three known strategies for the long-term time series prediction i.e. Recursive, Direct and DirRec are considered in combination with OP-ELM and compared with a baseline linear least squares model and Least-Squares Support Vector Machines (LS-SVM). Among these three strategies DirRec is the most time consuming and its usage with nonlinear models like LS-SVM, where several hyperparameters need to be adjusted, leads to relatively heavy computations. It is shown that OP-ELM, being also a nonlinear model, allows reasonable computational time for the DirRec strategy. In all our experiments, except one, OP-ELM with DirRec strategy outperforms the linear model with any strategy. In contrast to the proposed algorithm, LS-SVM behaves unstably without variable selection. It is also shown that there is no superior strategy for OP-ELM: any of three can be the best. In addition, the prediction accuracy of an ensemble of OP-ELM is studied and it is shown that averaging predictions of the ensemble can improve the accuracy (Mean Square Error) dramatically. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Improving Diamagnetic Flux Temporal Resolution to Measure ELM Energy Loss

    NASA Astrophysics Data System (ADS)

    Sieck, P. E.; Baylor, L. R.; Evans, T. E.; Leonard, A. W.; Osborne, T. H.; Strait, E. J.

    2010-11-01

    When an ELM occurs in a tokamak, a substantial loss of stored thermal energy can occur in a very short time, resulting in a change in the plasma diamagnetism. A diamagnetic loop is therefore an attractive diagnostic for characterizing the change in energy during ELMs. A loop external to the vessel can be used but it is bandwidth-limited by the vessel wall, therefore the signal is severely attenuated above 40 Hz in DIII-D. The temporal resolution can be improved by combining the (slow) diamagnetic signal with a properly scaled internal (fast) toroidal BT signal. The results agree with finely-spaced EFIT equilibrium reconstructions to within 10% before each ELM, but the diamagnetic calculation often shows up to twice the drop in energy at the ELM. The BT signal reveals the magnetic change completes in 0.5 ms or less with occasional dynamics above 10 kHz. This improved temporal resolution allows comparison of phenomenology in natural vs. pellet-triggered ELMs, and also effects of partial ELM suppression under resonant magnetic perturbation.

  10. Features of spontaneous and pellet-induced ELMs on the HL-2A tokamak

    NASA Astrophysics Data System (ADS)

    Huang, Y.; Liu, C. H.; Nie, L.; Feng, Z.; Ji, X. Q.; Yao, K.; Zhu, G. L.; Liu, Yi; Cui, Z. Y.; Yan, L. W.; Wang, Q. M.; Yang, Q. W.; Ding, X. T.; Dong, J. Q.; Duan, X. R.

    2012-11-01

    The pellet pacing ELM mitigation concept is being tested in some tokamaks such as ASDEX Upgrade, DIII-D and JET. By increasing the ELM frequency, the ELM size can be reduced and eventually suppressed to meet the lifetime requirements on ITER target plates. In the HL-2A tokamak, ELMy H-mode operation is routinely performed and small type-III ELMs with a high repetition rate and some type-I (or possibly large type-III) ELM events are observed. Large ELMs are often preceded by strong coherent magnetic oscillations, and produce obvious perturbations on plasma current Ip, electron density \\bar {n}_{edge} at the edge, stored energy WE, etc. The coherent magnetic oscillations before an ELM crash or during the ELM are measured by toroidal and poloidal Mirnov coils and analysed by the wavelet technique to study the spectral characteristics of the short time ELM events. Pellet injection experiments are performed in type-III ELMy H-mode plasmas and ELM-free H-mode plasmas to study the physics of pellet triggering ELM. The analyses of pellet-induced ELMs and spontaneous ELMs are presented. Because the pellet size is relatively large, it induces magnetic oscillations lasting longer than that of a natural ELM.

  11. Dutch audiology.

    PubMed

    Grobben, L M; van Ligtenberg, C L

    1977-01-01

    In the Netherlands audiological care is given at different stages. An attempt is made to screen the hearing of all Dutch babies between the ages of 8 and 12 months. At the age of 4 or over, general audiological care is given by the school medical service; referral is first to a family doctor, who may refer to an otolaryngologist. Curative medical care (examination and therapy) is the province of the family doctor and the otolaryngologist. Otolaryngologists and pediatricians can refer patients to one of 19 Audiological Centers distributed around the country, where a number of workers in different disciplines cooperate for habilitation and rehabilitation. These may include an otolaryngologist in charge, a psychologist, a speech and hearing therapist, an audiologist (usually a physicist or university-trained engineer), social worker, technician, ortho-pedagogue, audiology assistant, and teacher. There are at the moment 25 schools for the hard of hearing and 5 institutes for the deaf. These are often found in conjunction with Audiological Centers, the latter providing paramedical assistance to the pupils by agreement. Finally, the Dutch Organization for Preventive Medicine works to prevent hearing loss in noisy industries.

  12. Construct Validity of the Dutch Version of the 12-Item Partners in Health Scale: Measuring Patient Self-Management Behaviour and Knowledge in Patients with Chronic Obstructive Pulmonary Disease

    PubMed Central

    Lenferink, Anke; Effing, Tanja; Harvey, Peter; Battersby, Malcolm; Frith, Peter; van Beurden, Wendy; van der Palen, Job; Paap, Muirne C. S.

    2016-01-01

    Objective The 12-item Partners in Health scale (PIH) was developed in Australia to measure self-management behaviour and knowledge in patients with chronic diseases, and has undergone several changes. Our aim was to assess the construct validity and reliability of the latest PIH version in Dutch COPD patients. Methods The 12 items of the PIH, scored on a self-rated 9-point Likert scale, are used to calculate total and subscale scores (knowledge; coping; recognition and management of symptoms; and adherence to treatment). We used forward-backward translation of the latest version of the Australian PIH to define a Dutch PIH (PIH(Du)). Mokken Scale Analysis and common Factor Analysis were performed on data from a Dutch COPD sample to investigate the psychometric properties of the Dutch PIH; and to determine whether the four-subscale solution previously found for the original Australian PIH could be replicated for the Dutch PIH. Results Two subscales were found for the Dutch PIH data (n = 118); 1) knowledge and coping; 2) recognition and management of symptoms, adherence to treatment. The correlation between the two Dutch subscales was 0.43. The lower-bound of the reliability of the total scale equalled 0.84. Factor analysis indicated that the first two factors explained a larger percentage of common variance (39.4% and 19.9%) than could be expected when using random data (17.5% and 15.1%). Conclusion We recommend using two PIH subscale scores when assessing self-management in Dutch COPD patients. Our results did not support the four-subscale structure as previously reported for the original Australian PIH. PMID:27564410

  13. Construct Validity of the Dutch Version of the 12-Item Partners in Health Scale: Measuring Patient Self-Management Behaviour and Knowledge in Patients with Chronic Obstructive Pulmonary Disease.

    PubMed

    Lenferink, Anke; Effing, Tanja; Harvey, Peter; Battersby, Malcolm; Frith, Peter; van Beurden, Wendy; van der Palen, Job; Paap, Muirne C S

    2016-01-01

    The 12-item Partners in Health scale (PIH) was developed in Australia to measure self-management behaviour and knowledge in patients with chronic diseases, and has undergone several changes. Our aim was to assess the construct validity and reliability of the latest PIH version in Dutch COPD patients. The 12 items of the PIH, scored on a self-rated 9-point Likert scale, are used to calculate total and subscale scores (knowledge; coping; recognition and management of symptoms; and adherence to treatment). We used forward-backward translation of the latest version of the Australian PIH to define a Dutch PIH (PIH(Du)). Mokken Scale Analysis and common Factor Analysis were performed on data from a Dutch COPD sample to investigate the psychometric properties of the Dutch PIH; and to determine whether the four-subscale solution previously found for the original Australian PIH could be replicated for the Dutch PIH. Two subscales were found for the Dutch PIH data (n = 118); 1) knowledge and coping; 2) recognition and management of symptoms, adherence to treatment. The correlation between the two Dutch subscales was 0.43. The lower-bound of the reliability of the total scale equalled 0.84. Factor analysis indicated that the first two factors explained a larger percentage of common variance (39.4% and 19.9%) than could be expected when using random data (17.5% and 15.1%). We recommend using two PIH subscale scores when assessing self-management in Dutch COPD patients. Our results did not support the four-subscale structure as previously reported for the original Australian PIH.

  14. Disease prevalence in flounder (Platichthys flesus) from the Dutch Wadden Sea as indicator of environmental quality: A summary of 1988-2005 surveys

    NASA Astrophysics Data System (ADS)

    Vethaak, A. D.

    2013-09-01

    In 1988, epizootics of ulcer disease in the flatfish flounder in the Dutch Wadden Sea were reported near freshwater drainage sluices of IJsselmeer Lake, locally affecting up to 38.9% of fish. Other diseases such as fin rot and lymphocystis were less frequent, but followed a similar pattern. Results of follow-up surveys in the Wadden Sea in 1994-2005 confirm previous findings and also show significantly elevated ulcer prevalences at other smaller drainage works. The most likely stress factors that contributed to the development of the epizootics at these sites include osmotic stress, adverse water quality conditions including chemical contaminants, nutritional deficiencies, and obstruction to fish migration. It was shown that discharges of IJsselmeer Lake freshwater in 1988-96 had a wide effect on the prevalence and distribution of ulcers and lymphocystis in the western Wadden Sea. A general reduction in disease prevalence in flounder in the entire Dutch Wadden Sea was observed during 1988-2005, which was most likely due to a general improvement in water quality and locally improved habitat conditions for flounder near drainage sluices. Ulcer prevalences outside the two IJsselmeer Lake sluices (Den Oever and Kornwerderzand) declined in this period from approximately 30% to 10% for medium-sized fish. Other skin diseases have also displayed a downward trend at both sites in recent years, with prevalences falling sharply to below 1%. Elsewhere in the Wadden Sea and the Ems-Dollard estuary, disease prevalences have declined towards natural background levels (< 1%). It is concluded that skin diseases, especially ulcers, are useful indicators of environmental quality in the Wadden Sea.

  15. Effects of induced water stress on leaf trichome density and foliar nutrients of three elm (Ulmus) species: implications for resistance to the elm leaf beetle.

    PubMed

    Bosu, Paul P; Wagner, Michael R

    2007-06-01

    Seedlings of three elm species with variable susceptibility to the elm leaf beetle (Pyrrhalta luteola Müller) (Coleoptera: Chrysomelidae) were subjected to three water stress treatments (no stress, low stress, and high stress) in a greenhouse experiment. The species tested were Ulmus pumila L. (Siberian elm = highly susceptible), U. parvifolia Jacq. (Chinese elm = resistant), and U. americana L. (American elm = intermediate). The seedlings were analyzed for changes in the levels of selected host traits (trichome density, foliar concentration of nitrogen [N], phosphorus [P], potassium [K], calcium [Ca], magnesium [Mg], iron [Fe], and manganese [Mn]), some of which had previously been implicated in resistance to the elm leaf beetle. Density of leaf abaxial surface trichomes (simple, bulbous, and total trichomes) and foliar Fe and Mg concentrations increased significantly in the highly susceptible Siberian elms under water stress. In contrast, stress reduced trichome density in the moderately susceptible American elms, but it had no effect on levels of foliar mineral nutrients. The stress treatments had no influence on host traits in the resistant Chinese elms. The results suggest that environmental stress can alter plant traits that are likely involved in determining resistance of elms to the elm leaf beetle.

  16. Functional categorization of unique expressed sequence tags obtained from the yeast-like growth phase of the elm pathogen Ophiostoma novo-ulmi

    PubMed Central

    2011-01-01

    Background The highly aggressive pathogenic fungus Ophiostoma novo-ulmi continues to be a serious threat to the American elm (Ulmus americana) in North America. Extensive studies have been conducted in North America to understand the mechanisms of virulence of this introduced pathogen and its evolving population structure, with a view to identifying potential strategies for the control of Dutch elm disease. As part of a larger study to examine the genomes of economically important Ophiostoma spp. and the genetic basis of virulence, we have constructed an expressed sequence tag (EST) library using total RNA extracted from the yeast-like growth phase of O. novo-ulmi (isolate H327). Results A total of 4,386 readable EST sequences were annotated by determining their closest matches to known or theoretical sequences in public databases by BLASTX analysis. Searches matched 2,093 sequences to entries found in Genbank, including 1,761 matches with known proteins and 332 matches with unknown (hypothetical/predicted) proteins. Known proteins included a collection of 880 unique transcripts which were categorized to obtain a functional profile of the transcriptome and to evaluate physiological function. These assignments yielded 20 primary functional categories (FunCat), the largest including Metabolism (FunCat 01, 20.28% of total), Sub-cellular localization (70, 10.23%), Protein synthesis (12, 10.14%), Transcription (11, 8.27%), Biogenesis of cellular components (42, 8.15%), Cellular transport, facilitation and routes (20, 6.08%), Classification unresolved (98, 5.80%), Cell rescue, defence and virulence (32, 5.31%) and the unclassified category, or known sequences of unknown metabolic function (99, 7.5%). A list of specific transcripts of interest was compiled to initiate an evaluation of their impact upon strain virulence in subsequent studies. Conclusions This is the first large-scale study of the O. novo-ulmi transcriptome. The expression profile obtained from the yeast

  17. Observations of Harmonic Oscillations and ELM Magnetic Precursors in NSTX

    NASA Astrophysics Data System (ADS)

    Kelly, F.; Fredrickson, E.; Bell, R.; Tritz, K.; Maingi, R.; Takahashi, H.

    2010-11-01

    Recent experiments in the National Spherical Torus Experiment (NSTX) demonstrated the progressive suppression of edge localized modes (ELMs) with increasing lithium deposition. Sufficient lithium suppressed ELMs and made the occurrence of low-frequency, low-n harmonics more frequent. Signatures of these harmonic oscillations with a significant edge component were observed in both the high-n Mirnov magnetic and soft X-ray diagnostics of NSTX. Two distinct sets of harmonic oscillations can be observed during some ELM-free periods. The harmonic oscillations are consistent with modes localized in the edge with the frequency of the n = 1 harmonic near the rotation frequency of the edge plasma. NSTX magnetic diagnostics also observe distinctive signatures of ELMs. Transient n = 1 and n = 2 mode bursts and occasional higher n modes with frequency in the 30 to 90 kHz range occurred simultaneous with the increase in fast Da signal. These bursts of n = 1 and n = 2 modes resemble a model simulation of ELMs by T. Evans in which a bifurcation of magnetic topology is driven by nonlinear feedback amplification of thermoelectric currents from linear peeling-ballooning modes.

  18. Scaling Relationships for ELM Diverter Heat Flux on DIII D

    NASA Astrophysics Data System (ADS)

    Peters, E. A.; Makowski, M. A.; Leonard, A. W.

    2015-11-01

    Edge Localized Modes (ELMs) are periodic plasma instabilities that occur during H-mode operation in tokamaks. Left unmitigated, these instabilities result in concentrated particle and heat fluxes at the divertor and stand to cause serious damage to the plasma facing components of tokamaks. The purpose of this research is to find scaling relationships that predict divertor heat flux due to ELMs based on plasma parameters at the time of instability. This will be accomplished by correlating characteristic ELM parameters with corresponding plasma measurements and analyzing the data for trends. One early assessment is the effect of the heat transmission coefficient ? on the in/out asymmetry of the calculated ELM heat fluxes. Using IR camera data, further assessments in this study will continue to emphasize in/out asymmetry in ELMs, as this has important implications for ITER operation. Work supported in part by the US DOE, DE-AC52-07NA27344, DE-FC02-04ER54698, Office of Workforce Development for Teachers and Scientists (WDTS) under the Science Undergraduate Laboratory Internships Program (SULI).

  19. Modeling of extinguishing ELMs in detached divertor plasmas

    NASA Astrophysics Data System (ADS)

    Pigarov, A.; Krasheninnikov, S.; Hollmann, E.; Rognlien, T.

    2015-11-01

    Detached plasmas, the primary operational regime for divertors in next-step fusion devices, should be compatible with both good H-mode confinement and relatively small ELMs providing tolerable heat power loads on divertor targets. Here, dynamics of boundary plasma, impurities and material walls over a sequence of many type-I ELM events under detached divertor plasma conditions is studied with UEGDE-MB-W, the newest version of 2D edge plasma transport code, which incorporates Macro-Blob (MB) approach to simulate non-diffusive filamentary transport and various ``Wall'' (W) models for time-dependent hydrogen wall inventory and recycling. We present the results of multi-parametric analysis on the impact of the size and frequency of ELMs on the divertor plasma parameters where we vary the MB characteristics under different pedestals and divertor configurations. We discuss the conditions, under which small but frequent type-I ELMs (typical for high-power H-mode discharges on current tokamaks with hard deuterium gas puff) are not ``burning through'' the formed detached divertor plasma. In this case, the inner and outer divertors are filled by sub-eV, recombining, highly-impure plasma. Variations of impurity plasma content, radiation pattern, and deuterium wall inventory over the ELM cycle are analyzed. UEDGE-MB-W modeling results are compared to available experimental data.

  20. Comparing magnetic triggering of ELMs in TCV and ASDEX Upgrade

    NASA Astrophysics Data System (ADS)

    Kim, S. H.; Cavinato, M. M.; Dokuka, V.; Ivanov, A. A.; Khayrutdinov, R. R.; Lang, P. T.; Lister, J. B.; Lukash, V. E.; Martin, Y. R.; Medvedev, S. Yu; Villard, L.

    2009-05-01

    Frequency locking of edge localized modes (ELMs) to the vertical plasma movements induced by magnetic perturbations first demonstrated in TCV was successfully repeated in ASDEX Upgrade. However, the ELMs were triggered in ASDEX Upgrade when the plasma was moving down towards the X-point with a consequent decrease in the plasma current density in the edge region, in contrast to the previous observation on TCV in which ELMs were triggered when the edge current was increased by an upward plasma movement. This opposite behaviour observed in the magnetic triggering of ELMs has been investigated by using a free-boundary tokamak simulator, DINA-CH. The passive stabilization loops (PSLs) located inside the vacuum vessel of ASDEX Upgrade produce similar external linking flux changes to those generated by the G-coil sets in TCV for opposite vertical plasma movements. Therefore, both plasmas experience similar local flux surface expansions near the upper G-coil set and PSL when the ELMs are triggered. In ASDEX Upgrade, however, the localized expansion of the plasma flux surfaces near the upper PSL is observed with the global shrinkage of the plasma column accompanied by the downward plasma movement.

  1. Stability and ELM Characterization in I-Mode Pedestals

    NASA Astrophysics Data System (ADS)

    Walk, J. R.; Hughes, J. W.; Snyder, P. B.; Hubbard, A. E.; Terry, J. L.; White, A. E.; Whyte, D. G.; Baek, S. G.; Cziegler, I.; Edlund, E.

    2014-10-01

    The I-mode is a novel high-confinement regime explored on Alcator C-Mod, notable for its formation of an H-mode-like temperature pedestal without the accompanying density pedestal, maintaining L-mode particle confinement. I-mode exhibits a number of desirable properties for a reactor regime: among them, it naturally lacks large ELMs, avoiding the need for externally-applied ELM suppression. However, under certain conditions small, intermittent ELM-like events are seen. These events exhibit a range of phenomena in terms of edge and pedestal behavior, particularly for the ELM trigger - the majority of events are synchronized with the sawtooth heat pulse reaching the edge. The stationary pedestal structure is stable against peeling-ballooning MHD as calculated by ELITE in all cases, necessitating treatment of transient pedestal modification to characterize these events. We characterize these ELM events in terms of edge behavior, particularly the modification of the temperature pedestal, edge turbulence and fluctuations, and peeling-ballooning MHD stability. This work is supported by USDoE Award DE-FC02-99ER54512.

  2. ELM-KNN for photometric redshift estimation of quasars

    NASA Astrophysics Data System (ADS)

    Zhang, Yanxia; Tu, Yang; Zhao, Yongheng; Tian, Haijun

    2017-06-01

    We explore photometric redshift estimation of quasars with the SDSS DR12 quasar sample. Firstly the quasar sample is separated into three parts according to different redshift ranges. Then three classifiers based on Extreme Learning Machine (ELM) are created in the three redshift ranges. Finally k-Nearest Neighbor (kNN) approach is applied on the three samples to predict photometric redshifts of quasars with multiwavelength photometric data. We compare the performance with different input patterns by ELM-KNN with that only by kNN. The experimental results show that ELM-KNN is feasible and superior to kNN (e.g. rms is 0.0751 vs. 0.2626 for SDSS sample), in other words, the ensemble method has the potential to increase regressor performance beyond the level reached by an individual regressor alone and will be a good choice when facing much more complex data.

  3. Investigation of dynamics of ELM crashes and their mitigation techniques

    SciTech Connect

    Pankin, Alexei Y.

    2015-08-14

    The accurate prediction of H-mode pedestal dynamics is critical for planning experiments in existing tokamaks and in the design of future tokamaks such as ITER and DEMO. The main objective of the proposed research is to advance the understanding of the physics of H-mode pedestal. Through advances in coupled kinetic-MHD simulations, a new model for H-mode pedestal and ELM crashes as well as an improved model for the bootstrap current will be developed. ELMmitigation techniques will also be investigated. The proposed research will help design efficient confinement scenarios and reduce transient heat loads on the divertor and plasma facing components. During the last two years, the principal investigator (PI) of this proposal actively participated in physics studies related to the DOE Joint Research Targets. These studies include the modeling of divertor heat load in the DIII-D, Alcator C-Mod, and NSTX tokamaks in 2010, and the modeling of H-mode pedestal structure in the DIII-D tokamak in 2011. It is proposed that this close collaboration with experimentalists from major US tokamaks continue during the next funding period. Verification and validation will be a strong component of the proposed research. During the course of the project, advances will be made in the following areas; Dynamics of the H-mode pedestal buildup and recovery after ELM crashes – The effects of neutral fueling, particle and thermal pinches will be explored; Dynamics of ELM crashes in realistic tokamak geometries – Heat loads associated with ELM crashes will be validated against experimental measurements. An improved model for ELM crashes will be developed; ELM mitigation – The effect of resonant magnetic perturbations on ELMs stability and their evolution will be investigated; Development of a new bootstrap current model – A reduced model for will be developed through careful verification of existing models for bootstrap current against first-principle kinetic neoclassical simulations

  4. ELM: an Algorithm to Estimate the Alpha Abundance from Low-resolution Spectra

    NASA Astrophysics Data System (ADS)

    Bu, Yude; Zhao, Gang; Pan, Jingchang; Bharat Kumar, Yerra

    2016-01-01

    We have investigated a novel methodology using the extreme learning machine (ELM) algorithm to determine the α abundance of stars. Applying two methods based on the ELM algorithm—ELM+spectra and ELM+Lick indices—to the stellar spectra from the ELODIE database, we measured the α abundance with a precision better than 0.065 dex. By applying these two methods to the spectra with different signal-to-noise ratios (S/Ns) and different resolutions, we found that ELM+spectra is more robust against degraded resolution and ELM+Lick indices is more robust against variation in S/N. To further validate the performance of ELM, we applied ELM+spectra and ELM+Lick indices to SDSS spectra and estimated α abundances with a precision around 0.10 dex, which is comparable to the results given by the SEGUE Stellar Parameter Pipeline. We further applied ELM to the spectra of stars in Galactic globular clusters (M15, M13, M71) and open clusters (NGC 2420, M67, NGC 6791), and results show good agreement with previous studies (within 1σ). A comparison of the ELM with other widely used methods including support vector machine, Gaussian process regression, artificial neural networks, and linear least-squares regression shows that ELM is efficient with computational resources and more accurate than other methods.

  5. ELM: AN ALGORITHM TO ESTIMATE THE ALPHA ABUNDANCE FROM LOW-RESOLUTION SPECTRA

    SciTech Connect

    Bu, Yude; Zhao, Gang; Kumar, Yerra Bharat; Pan, Jingchang E-mail: gzhao@nao.cas.cn

    2016-01-20

    We have investigated a novel methodology using the extreme learning machine (ELM) algorithm to determine the α abundance of stars. Applying two methods based on the ELM algorithm—ELM+spectra and ELM+Lick indices—to the stellar spectra from the ELODIE database, we measured the α abundance with a precision better than 0.065 dex. By applying these two methods to the spectra with different signal-to-noise ratios (S/Ns) and different resolutions, we found that ELM+spectra is more robust against degraded resolution and ELM+Lick indices is more robust against variation in S/N. To further validate the performance of ELM, we applied ELM+spectra and ELM+Lick indices to SDSS spectra and estimated α abundances with a precision around 0.10 dex, which is comparable to the results given by the SEGUE Stellar Parameter Pipeline. We further applied ELM to the spectra of stars in Galactic globular clusters (M15, M13, M71) and open clusters (NGC 2420, M67, NGC 6791), and results show good agreement with previous studies (within 1σ). A comparison of the ELM with other widely used methods including support vector machine, Gaussian process regression, artificial neural networks, and linear least-squares regression shows that ELM is efficient with computational resources and more accurate than other methods.

  6. VizieR Online Data Catalog: The ELM survey. VI. 11 new ELM WD binaries (Gianninas+, 2015)

    NASA Astrophysics Data System (ADS)

    Gianninas, A.; Kilic, M.; Brown, W. R.; Canton, P.; Kenyon, S. J.

    2016-02-01

    We used the 6.5m MMT telescope equipped with the Blue Channel spectrograph, the 200 inch Hale telescope equipped with the Double spectrograph, the Kitt Peak National Observatory 4m telescope equipped with the R-C spectrograph, and more recently with Kitt Peak Ohio State Multi-Object Spectrograph (KOSMOS), to obtain spectroscopy of our 11 targets in several observing runs. We have also been obtaining radial-velocity measurements for candidates from other sources including the Large Sky Area Multi-Object Spectroscopy Telescope (LAMOST). Those 11 new Extremely low-mass white dwarf (ELM WD) binaries bring the total of ELM WDs identified by the ELM Survey up to 73. (4 data files).

  7. ELM-induced transient tungsten melting in the JET divertor

    NASA Astrophysics Data System (ADS)

    Coenen, J. W.; Arnoux, G.; Bazylev, B.; Matthews, G. F.; Autricque, A.; Balboa, I.; Clever, M.; Dejarnac, R.; Coffey, I.; Corre, Y.; Devaux, S.; Frassinetti, L.; Gauthier, E.; Horacek, J.; Jachmich, S.; Komm, M.; Knaup, M.; Krieger, K.; Marsen, S.; Meigs, A.; Mertens, Ph.; Pitts, R. A.; Puetterich, T.; Rack, M.; Stamp, M.; Sergienko, G.; Tamain, P.; Thompson, V.; Contributors, JET-EFDA

    2015-02-01

    The original goals of the JET ITER-like wall included the study of the impact of an all W divertor on plasma operation (Coenen et al 2013 Nucl. Fusion 53 073043) and fuel retention (Brezinsek et al 2013 Nucl. Fusion 53 083023). ITER has recently decided to install a full-tungsten (W) divertor from the start of operations. One of the key inputs required in support of this decision was the study of the possibility of W melting and melt splashing during transients. Damage of this type can lead to modifications of surface topology which could lead to higher disruption frequency or compromise subsequent plasma operation. Although every effort will be made to avoid leading edges, ITER plasma stored energies are sufficient that transients can drive shallow melting on the top surfaces of components. JET is able to produce ELMs large enough to allow access to transient melting in a regime of relevance to ITER. Transient W melt experiments were performed in JET using a dedicated divertor module and a sequence of IP = 3.0 MA/BT = 2.9 T H-mode pulses with an input power of PIN = 23 MW, a stored energy of ˜6 MJ and regular type I ELMs at ΔWELM = 0.3 MJ and fELM ˜ 30 Hz. By moving the outer strike point onto a dedicated leading edge in the W divertor the base temperature was raised within ˜1 s to a level allowing transient, ELM-driven melting during the subsequent 0.5 s. Such ELMs (δW ˜ 300 kJ per ELM) are comparable to mitigated ELMs expected in ITER (Pitts et al 2011 J. Nucl. Mater. 415 (Suppl.) S957-64). Although significant material losses in terms of ejections into the plasma were not observed, there is indirect evidence that some small droplets (˜80 µm) were released. Almost 1 mm (˜6 mm3) of W was moved by ˜150 ELMs within 7 subsequent discharges. The impact on the main plasma parameters was minor and no disruptions occurred. The W-melt gradually moved along the leading edge towards the high-field side, driven by j × B forces. The evaporation rate determined

  8. [Diagnosis and treatment of gastroesophageal reflux disease in the mentally retarded: guidelines of a multidisciplinary consensus work group. Dutch Association of Physicians in Care of Mentally Handicapped].

    PubMed

    Gimbel, H

    2000-06-10

    Gastroesophageal reflux disease (GORD) is more frequent among people with intellectual disability than among the intellectually normal population. Also GORD is more serious in this population. The diagnosis is often missed, because most intellectually disabled cannot express their complaints of GORD. For that reason a multidisciplinary working group of the Dutch Association of physicians active in the care of persons with a mental handicap has developed guidelines. The working group recommends endoscopy in case of a (alarm) symptoms: haematemesis, prolonged vomiting, irondeficiency anaemia e.c.i., and a 24 hour oesophageal pH test in case of b (aspecific) symptoms: recurrent pneumonia, refusal of food, regurgitation, rumination, dental erosions. In general most patients are cured with drug treatment (omeprazol or another proton pump inhibitor). If symptoms are not improved after 6 months of optimal treatment, surgical treatment may be considered.

  9. Significant linkage disequilibrium between the Huntington disease gene and the loci D4S10 and D4S95 in the Dutch population

    SciTech Connect

    Skraastad, M.I.; Van de Vosse, E.; Belfroid, R.; Hoeld, K.; Vegter-van der Vlis, M.; Bakker, E.; van Ommen, G.J.B. ); Sandkuijl, L.A. )

    1992-10-01

    Significant linkage disequilibrium has been found between the Huntington disease (HD) gene and DNA markers located around D4S95 and D4S98. The linkage-disequilibrium studies favor the proximal location of the HD gene, in contrast to the conflicting results of recombination analyses. The authors have analyzed 45 Dutch HD families with 19 DNA markers and have calculated the strength of linkage disequilibrium. Highly significant linkage disequilibrium has been detected with D4S95, consistent with the studies in other populations. In contrast with most other studies, however, the area of linkage disequilibrium extends from D4S10 proximally to D4S95, covering 1,100 kb. These results confirm that the HD gene most likely maps near D4S95. 28 refs., 1 fig., 2 tabs.

  10. Psychometric validation of the Dutch translation of the quality of life in reflux and dyspepsia (QOLRAD) questionnaire in patients with gastroesophageal reflux disease.

    PubMed

    Engels, Leopold G J B; Klinkenberg-Knol, Elly C; Carlsson, Jonas; Halling, Katarina

    2010-08-17

    The Quality of Life in Reflux and Dyspepsia (QOLRAD) questionnaire is one of the best-characterized disease-specific instruments that captures health-related problems and symptom-patterns in patients with gastroesophageal reflux disease (GERD). This paper reports the psychometric validation of a Dutch translation of the QOLRAD questionnaire in gastroenterology outpatients with GERD. Patients completed the QOLRAD questionnaire at visit 1 (baseline), visit 2 (after 2, 4 or 8 weeks of acute treatment with esomeprazole 40 mg once daily), and visit 4 (after 6 months with on-demand esomeprazole 40 mg once daily or continuous esomeprazole 20 mg once daily). Symptoms were assessed at each visit, and patient satisfaction was assessed at visits 2 and 4. Of the 1166 patients entered in the study, 97.3% had moderate or severe heartburn and 55.5% had moderate or severe regurgitation at baseline. At visit 2, symptoms of heartburn and regurgitation were mild or absent in 96.7% and 97.7%, respectively, and 95.3% of patients reported being satisfied with the treatment. The internal consistency and reliability of the QOLRAD questionnaire (range: 0.83-0.92) supported construct validity. Convergent validity was moderate to low. Known-groups validity was confirmed by a negative correlation between the QOLRAD score and clinician-assessed severity of GERD symptoms. Effect sizes (1.15-1.93) and standardized response means (1.17-1.86) showed good responsiveness to change. GERD symptoms had a negative impact on patients' lives. The psychometric characteristics of the Dutch translation of the QOLRAD questionnaire were found to be satisfactory, with good reliability and responsiveness to change, although convergent validity was at best moderate.

  11. Annual incidence of non-specific low back pain as an occupational disease attributed to whole-body vibration according to the National Dutch Register 2005-2012.

    PubMed

    Kuijer, P Paul F M; van der Molen, Henk F; Schop, Astrid; Moeijes, Fred; Frings-Dresen, Monique H W; Hulshof, Carel T J

    2015-01-01

    Non-specific low back pain (nLBP) is the second most important reason for sick leave in the Netherlands, and more than 50% of the workers on sick leave attribute these complaints to their work. To stimulate recognition and prevention, an occupational disease (OD) registration-guideline was implemented for the assessment of the work-relatedness of nLBP in the Netherlands in 2005. The aim of this study is to present the annual incidence of nLBP as an OD and specifically for whole-body vibration (WBV) including patient characteristics such as age, sick leave and actions initiated by the occupational physician (OP). The data were retrieved from the National Dutch Register for 2005-2012. Each year about 118 OPs reported 509 cases (SD 139) of nLBP as an OD in a Dutch working population of 7.5 million workers (8% of all annual reported ODs). Less than 1% of these cases were attributed to WBV: 94% were men, 45% were between 51 and 60 years and 35% were on sick leave for more than 2 weeks. Most initiated actions were ergonomic interventions (35%). The number of notified cases of nLPB as an occupational disease attributed to whole-body vibration is low with less than 1% of all cases in the Netherlands. An explanation is that other work-related risk factors for nLBP such as lifting are more frequently occurring, more visible and have a higher attributable risk than WBV. However, continuing attention for WBV remains warranted given a higher percentage of cases with sick leave of more than 2 weeks.

  12. VIEW OF ELM CIRCLE, FROM BETWEEN FACILITIES 750 AND 750. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF ELM CIRCLE, FROM BETWEEN FACILITIES 750 AND 750. VIEW FACING EAST/NORTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  13. VIEW OF PLAYGROUND #4 NEAR ELM CIRCLE, SHOWING PICNIC TABLE. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF PLAYGROUND #4 NEAR ELM CIRCLE, SHOWING PICNIC TABLE. VIEW FACING EAST/NORTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  14. Phloem Necrosis of American Elm in the Mississippi Delta

    Treesearch

    T. H. Filer

    1966-01-01

    Phloem necrosis in elms, caused by the virus Morsus ulmi Holmes, has been found at Rolling Fork, Mississippi, 60 miles northwest of Jackson and 47 miles north of Vicksburg, in the Delta hardwoods area. It was first reported in Mississippi in 1941, when it was found at Jackson, and it appeared in the northeastern part of the State in 1945.

  15. Intra- and interspecific hybridization in invasive Siberian elm

    USDA-ARS?s Scientific Manuscript database

    Although numerous studies have examined the invasion history of herbaceous plants, few studies have investigated the invasion biology of woody plants. In this study, we determined whether inter-specific hybridization was necessary before invasiveness could evolve in the Siberian elm, Ulmus pumila. P...

  16. Formulation and application of methoxychlor for elm bark beetle control

    Treesearch

    R. A. Cuthbert; J. H. Barger; A. C. Lincoln; P. A. Reed

    1973-01-01

    American elm trees, Ulmus americana L., were sprayed with different formulations of methoxychlor by mistblower, hydraulic sprayer or helicopter. Twig-crotches were collected from sprayed trees for GLC assay and Scolytus multistriatus (Marsham) bioassay. Hydraulic deposits were heaviest but the mistblower was more efficient in terms...

  17. VIEW FROM CENTER OF ELM AVENUE, LOOKING WEST INTO SECTION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM CENTER OF ELM AVENUE, LOOKING WEST INTO SECTION L. AT LEFT STANDS THE PONDEROUS MCDANIEL MAUSOLEUM, WHICH SHOWS THE INFLUENCE OF FRANK FURNESS ON H. Q. FRENCH’S 1887 DESIGN - Woodlands Cemetery, 4000 Woodlands Avenue, Philadelphia, Philadelphia County, PA

  18. 65. VIEW OF THE OLMSTED ELM, SOUTH LAWN, AND WEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    65. VIEW OF THE OLMSTED ELM, SOUTH LAWN, AND WEST SLOPE. SHOWN IN THE LEFT FOREGROUND ARE THE RESTORED LAWN EDGE AND THE HISTORIC ENGLISH YEW. (DUPLICATE OF HABS No. MA-1168-31) - Fairsted, 99 Warren Street, Brookline, Norfolk County, MA

  19. 67. VIEW FROM BENEATH THE OLMSTED ELM LOOKING TO THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    67. VIEW FROM BENEATH THE OLMSTED ELM LOOKING TO THE SOUTH LAWN AND WEST SLOPE. THERE IS A NEW GRASS BAY ON THE WEST SLOP, SHOWN IN THE BACKGROUND. (DUPLICATE OF HABS No. ma-1168-33) - Fairsted, 99 Warren Street, Brookline, Norfolk County, MA

  20. 75. VIEW LOOKING EAST FROM THE OLMSTED ELM IN THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    75. VIEW LOOKING EAST FROM THE OLMSTED ELM IN THE SOUTH LAWN TO THE ROCK GARDEN. VIEW INCLUDES HISTORIC ENGLISH YEW ON RIGHT, CRAB APPLE IN CENTER. (DUPLICATE OF HABS No. MA-1168-46) - Fairsted, 99 Warren Street, Brookline, Norfolk County, MA

  1. Characteristics of pre-ELM structures during ELM control experiment on JET with n  =  2 magnetic perturbations

    NASA Astrophysics Data System (ADS)

    Gao, Y.; Rack, M.; Liang, Y.; Sieglin, B.; Denner, P.; Contributors, JET

    2016-09-01

    Radially propagating pre-ELM (edge localized mode) structures in the heat flux profile on the outer divertor have been observed both with and without magnetic perturbations on Joint European Torus. Recently pre-ELM structures over 80% of the ELM cycle are observed. The effects of n  =  2 fields on pre-ELM structures are presented and analysed in detail. Redistribution of the inter-ELM heat load with the appearances of pre-ELM structures suggest that a wider energy wetted area could be achieved by the application of n  =  2 fields. The influences of q 95 and gas puffing position on the change of pre-ELM structures are studied. Pre-ELM structures are normally long lived (several milliseconds) and appear consecutively with n  =  2 fields, but do not necessarily lead to an ELM crash. The experimental observations suggest that the changed magnetic topology might be a possible explanation for the propagating structures.

  2. On Equivalence of FIS and ELM for Interpretable Rule-Based Knowledge Representation.

    PubMed

    Wong, Shen Yuong; Yap, Keem Siah; Yap, Hwa Jen; Tan, Shing Chiang; Chang, Siow Wee

    2015-07-01

    This paper presents a fuzzy extreme learning machine (F-ELM) that embeds fuzzy membership functions and rules into the hidden layer of extreme learning machine (ELM). Similar to the concept of ELM that employed the random initialization technique, three parameters of F-ELM are randomly assigned. They are the standard deviation of the membership functions, matrix-C (rule-combination matrix), and matrix-D [don't care (DC) matrix]. Fuzzy if-then rules are formulated by the rule-combination Matrix of F-ELM, and a DC approach is adopted to minimize the number of input attributes in the rules. Furthermore, F-ELM utilizes the output weights of the ELM to form the target class and confidence factor for each of the rules. This is to indicate that the corresponding consequent parameters are determined analytically. The operations of F-ELM are equivalent to a fuzzy inference system. Several benchmark data sets and a real world fault detection and diagnosis problem have been used to empirically evaluate the efficacy of the proposed F-ELM in handling pattern classification tasks. The results show that the accuracy rates of F-ELM are comparable (if not superior) to ELM with distinctive ability of providing explicit knowledge in the form of interpretable rule base.

  3. High prevalence of low bone mineral density in patients with Inflammatory Bowel Disease in the setting of a peripheral Dutch hospital.

    PubMed

    Van Schaik, Fiona D M; Verhagen, Marc A M T; Siersema, Peter D; Oldenburg, Bas

    2008-09-01

    Osteopenia and osteoporosis are frequently encountered in patients with Inflammatory Bowel Disease (IBD). Our aims were to evaluate the actual practice of screening for low bone mineral density (BMD) by dual energy X-ray absorptiometry (DEXA), to determine the prevalence of low BMD and to investigate the risk factors associated with a low BMD in the IBD population of a regional Dutch hospital. A retrospective chart review was performed in 474 patients (259 with ulcerative colitis, 210 with Crohn's disease and 5 with indeterminate colitis). DEXA results and potential predictive factors of low BMD were documented. Predictive factors of low BMD were assessed by logistic regression. DEXA was performed in 168 IBD patients (35.4%). A low BMD (T-score<-1) was present in 64.3%. Osteoporosis (T-score<-2.5) was found in 23.8%. Low BMI, older age at the moment of diagnosis and male gender were found to be predictive factors of low BMD. For patients with osteoporosis, disease duration was an additional predictive factor. After subgroup analysis predictive factors were found to be the same in patients with Crohn's disease. The prevalence of osteopenia and osteoporosis in IBD patients in a regional centre is as high as the prevalence rates reported from tertiary referral centres. A low BMI, an older age at the moment of diagnosis and male gender were predictive factors of low BMD. Prediction of osteoporosis and osteopenia using risk factors identified in this and previous studies is presently not feasible.

  4. Type-I ELM substructure on the divertor target plates in ASDEX Upgrade

    NASA Astrophysics Data System (ADS)

    Eich, T.; Herrmann, A.; Neuhauser, J.; Dux, R.; Fuchs, J. C.; Günter, S.; Horton, L. D.; Kallenbach, A.; Lang, P. T.; Maggi, C. F.; Maraschek, M.; Rohde, V.; Schneider, W.; ASDEX Upgrade Team

    2005-06-01

    In the ASDEX Upgrade tokamak, the power deposition structures on the divertor target plates during type-I edge localized modes (ELMs) have been investigated by infrared thermography. In addition to the axisymmetric strike line, several poloidally displaced stripes are resolved, identifying an ELM as a composite of several subevents. This pattern is interpreted as being a signature of the helical perturbations in the low field side edge during the non-linear ELM evolution. Based on this observation, the ELM related magnetic perturbation in the midplane can be derived from the target load pattern. In the start phase of an ELM collapse, average toroidal mode numbers around n ap 3-5 are found evolving to values of n ap 12-14 during the ELM power deposition maximum. Further information about the non-linear evolution of the ELM mode structure is obtained from statistical analyses of the spatial distribution, heat flux amplitudes and number of single stripes.

  5. ELM Destabilization by Externally Applied Non-Axisymmetric Magnetic Perturbations in NSTX

    SciTech Connect

    Canik, John; Maingi, Rajesh; Evans, T.E.; Bell, R. E.; Gerhardt, S. P.; Kugel, H. W.; LeBlanc, B. P.; Manickam, J.; Menard, J. E.; Osborne, T. H.; Park, Jin Myung; Paul, S.; Snyder, P. B.; Sabbagh, S. A.; Unterberg, Ezekial A

    2010-01-01

    We report on a recent set of experiments performed in NSTX to explore the effects of non-axisymmetric magnetic perturbations on the stability of edge-localized modes (ELMs). The application of these 3D fields in NSTX was found to have a strong effect on ELM stability, including the destabilization of ELMs in H-modes otherwise free of large ELMs. Exploiting the effect of the perturbations, ELMs have been controllably introduced into lithium-enhanced ELM-free H-modes, causing a reduction in impurity accumulation while maintaining high confinement. Although these experiments show the principle of the combined use of lithium coatings and 3D fields, further optimization is required in order to reduce the size of the induced ELMs.

  6. Characteristics of type I and type III ELM precursors in ASDEX upgrade

    NASA Astrophysics Data System (ADS)

    Kass, T.; Günter, S.; Maraschek, M.; Suttrop, W.; Zohm, H.; ASDEX Upgrade Team

    1998-01-01

    The temporal evolution of the edge electron pressure gradient during the development of a type I ELM shows that proximity of ∇pedge to the ideal ballooning limit is not sufficient to trigger a type I ELM. Thus, the MHD structure of ELMs is investigated further. The present discussion focuses on the phenomenology of type I and type III ELM precursors. The ELM precursor types are well distinguished by their frequency behaviour and mode structure. The type I ELM precursor oscillation originates from a thin layer close to the plasma edge. For type III ELMs, on the contrary, ∇pedge has a much stronger influence as indicated by their occurrence during L mode.

  7. Effects of simulated acid rain, ozone and sulfur dioxide on suitability of elms for elm leaf beetle

    Treesearch

    Richard W. Hall; Jack H. Barger; Alden M. Townsend

    1988-01-01

    Cuttings from two clonally propagated elm hybrids ('Pioneer' and 'Homestead') were treated with ozone (03), sulfur dioxide (S02), simulated acid rain or left untreated. Fumigants were applied 7 hours per day, 5 days per week for 9 weeks in open-top chambers. Fumigation treatments were: 0.1 ppm 0

  8. ELM PARTICLE AND ENERGY TRANSPORT IN THE SOL AND DIVERTOR OF DIII-D

    SciTech Connect

    FENSTERMACHER,ME; LEONARD,AW; SNYDER,PB; BOEDO,JA; COLCHIN,RJ; GROEBNER,RJ; GRAY,DS; GROTH,M; HOLLMANN,E; LASNIER,CJ; OSBORNE,TH; PETRIE,TW; RUDAKOV,DL; TAKAHASHI,H; WATKINS,JG; ZENG,L

    2003-04-01

    A271 ELM PARTICLE AND ENERGY TRANSPORT IN THE SOL AND DIVERTOR OF DIII-D. Results from a series of dedicated experiments measuring the effect of particle and energy pulses from Type-I Edge Localized Modes (ELMs) in the DIII-D scrape-off layer (SOL) and divertor are compared with a simple model of ELM propagation in the boundary plasma. The simple model asserts that the propagation of ELM particle and energy perturbations is dominated by ion parallel convection along SOL fields lines and the recovery from the ELM perturbation is determined by recycling physics. Time scales associated with the initial changes of boundary plasma parameters are expected to be on the order of the ion transit time from the outer midplane, where the ELM instability is initiated, to the divertor targets. To test the model, the ion convection velocity is changed in the experiment by varying the plasma density. At moderate to high density, n{sub e}/n{sub Gr} = 0.5-0.8, the delays in the response of the boundary plasma to the midplane ELM pulses, the density dependence of those delays and other observations are consistent with the model. However, at the lowest densities, n{sub e}/n{sub Gr} {approx} 0.35, small delays between the response sin the two divertors, and changes in the response of the pedestal thermal energy to ELM events, indicate that additional factors including electron conduction in the SOL, the pre-ELM condition of the divertor plasma, and the ratio of ELM instability duration to SOL transit time, may be playing a role. The results show that understanding the response of the SOL and divertor plasmas to ELMs, for various pre-ELM conditions, is just as important to predicting the effect of ELM pulses on the target surfaces of future devices as is predicting the characteristics of the ELM perturbation of the core plasma.

  9. High coronary heart disease rates among Dutch women of the baby boom, born 1945-1959: age-cohort analysis and projection.

    PubMed

    Bonneux, L; Looman, C W N

    2003-09-01

    After a steep decline in older generations, coronary heart disease mortality is stagnating in female cohorts born after the Second World War. We analysed past trends and predicted future health care needs for coronary heart disease in the Dutch population. A loglinear age-cohort model relates numbers of deaths and hospital admissions for coronary heart disease to sex, age, birth cohort and population size, and projects age-cohort changes over the future population. Population size, population forecasts and coronary heart disease mortality (period 1970-1999) are from vital statistics. Numbers of hospitalised acute coronary events are from the nationwide hospital register (period 1980-1999). Among men, the rate ratios of deaths and hospital admissions were, respectively, 0.21 (death) and 0.78 (survivors at discharge) in the cohorts born in the period 1948-1962 compared to the period 1918-1922. Among women, the same rate ratios were 0.41 and 1.89. The projection model predicts 22% less deaths from coronary heart disease and 22% more survivors of an infarction in 2015, among men. Among women, there will be 5% less deaths and 70% more survivors of an infarction, most of these being middle age members of the baby boom cohorts. Stagnating all-cause mortality is correlated with an upward trend in coronary heart disease risk in the female baby boomers. Heart health care needs among middle-aged women will increase sharply. These changes are correlated to high lung cancer mortality and high smoking rates in these cohorts.

  10. Dutch surgery in Japan.

    PubMed

    van Gulik, Thomas M; Nimura, Yuji

    2005-01-01

    An isolation policy was adopted in feudal Japan from 1639 to 1853 owing to the fear of foreign influence. During those 200 years of isolation, all foreigners were withheld from the country with the exception of the Dutch, who were permitted to establish a trading post on a small island in the Bay of Nagasaki, called Decima. Western culture and science reached the Japanese exclusively through the Dutch on Decima. Health care on Decima was provided by Dutch barber-surgeons, who introduced Western surgical practice in Japan. Official interpreters were the only Japanese allowed on Decima. It was from among these interpreters that the first Japanese surgeons arose who, having mastered the Dutch language, translated several Dutch anatomic and surgical texts. Genpaku Sugita translated a Dutch anatomy textbook into Japanese, which was completed in 1774. This book, entitled Kaitai Shinsho [New Book on Anatomy], was the first Western scientific monograph to be translated entirely into Japanese. Several Dutch surgical schools were founded through which Dutch surgery, known in Japan as "surgery of the red-haired" was propagated. According to the custom of the surgical guilds in Holland, certificates were granted to Japanese apprentices who had completed their training in Dutch surgery. About 60 Dutch surgeons had served on Decima up to 1850, providing the basis for surgery to develop in Japan. Among them, Philipp Franz von Siebold was an exceptional scholar who also had a great impact in making Japanese culture known to the Western world.

  11. Characterization of density fluctuations during ELMs in the DIII-D tokamak

    NASA Astrophysics Data System (ADS)

    Coda, S.; Porkolab, M.; Burrell, K. H.

    2001-12-01

    Bursts of turbulence associated with ELMs have been studied systematically in DIII-D with a multichannel phase contrast imaging (PCI) diagnostic, which is sensitive to the long poloidal wavelength components of the density fluctuations in the outer edge of the tokamak. A comparison of the temporal dynamics of the turbulence with the signature Dα signal from the divertor has revealed systematic differences between type I and type III ELMs: even though precursor fluctuations are sometimes seen before type I ELMs, the PCI signal level remains high until the peak in the Dα signal; by contrast, in type III ELMs the fluctuation burst precedes the Dα peak by 0.4-0.6 ms. Type I ELMs can generate `echoes', i.e. secondary bursts, in the scrape-off layer. Coherent modes are observed during type III ELMs only. The radial and temporal correlation structures and the spectral properties of the turbulence during the transient ELM phase have been reconstructed by averaging over multiple ELMs, in order to improve the statistical accuracy. ELM turbulence is found to share many properties with L mode turbulence, including the main qualitative features of radial wavenumber and frequency spectra and radial dispersion relations. However, features unique to ELM turbulence are also identified.

  12. Real-time control of the period of individual ELMs by EC power on TCV

    NASA Astrophysics Data System (ADS)

    Felici, F.; Rossel, J. X.; Duval, B. P.; Coda, S.; Goodman, T. P.; Martin, Y.; Moret, J.-M.; Sauter, O.; the TCV Team

    2013-11-01

    The period of individual type-I edge-localized modes (ELMs) in TCV H-mode plasmas is controlled by real-time controlled application of electron cyclotron (EC) power close to the plasma pedestal. An ELM pacing algorithm, closely related to sawtooth pacing (Goodman et al (2011 Phys. Rev. Lett. 106 245002)) has been implemented in the TCV control system. This algorithm switches the EC power to a low level after detecting an ELM, and subsequently increases the power to a higher level after a pre-set time interval, stimulating the advent of the next ELM. While the mean ELM period is observed to depend only on the mean power applied, ELM pacing is shown to significantly regularize the ELM period with respect to the case of continuously applied power. It is also shown that the ELM period can be changed from one ELM to the next on time scales shorter than the global energy confinement time. These results present a challenging benchmark to physics-based pedestal models and can point towards obtaining a deeper understanding of the physics of individual ELM cycles.

  13. Extensive statistical analysis of ELMs on JET with a carbon wall

    NASA Astrophysics Data System (ADS)

    Murari, A.; Pisano, F.; Vega, J.; Cannas, B.; Fanni, A.; Gonzalez, S.; Gelfusa, M.; Grosso, M.; EFDA Contributors, JET

    2014-11-01

    Edge localized modes (ELMs) are bursts of instabilities which deteriorate the confinement of H mode plasmas and can cause damage to the divertor of next generation of devices. On JET individual discharges can exhibit hundreds of ELMs but typically in the literature, mainly due to the lack of automatic analysis tools, single papers investigate only the behaviour of tens of individual ELMs. In this paper, an original tool, the universal event locator (UMEL), is applied to the problem of automatically identifying the time location of ELMs. With this approach, databases of hundreds of thousands of ELMs can be built with reasonable effort. The analysis has then been focused on the investigation of the statistical distribution of the inter-ELM intervals at steady state for type I ELMs. Numerous probability distributions have been tested to perform the data analysis and different distributions provide a best fit for sets of data from different experiments. This result constitutes robust experimental confirmation that type I ELMs are not all necessarily the same type of instability. Moreover, the most likely distributions are not memoryless, meaning that the waiting time, from a particular instant until the next ELM, does depend on the time elapsed from the previous event. These properties, confirmed by this investigation on JET, pose important constraints on the models aimed at describing the ELM dynamics. This work also demonstrates the widespread applicability of the UMEL tool.

  14. Mexican Hat Wavelet Kernel ELM for Multiclass Classification

    PubMed Central

    Wang, Jie; Ma, Tian-Lei

    2017-01-01

    Kernel extreme learning machine (KELM) is a novel feedforward neural network, which is widely used in classification problems. To some extent, it solves the existing problems of the invalid nodes and the large computational complexity in ELM. However, the traditional KELM classifier usually has a low test accuracy when it faces multiclass classification problems. In order to solve the above problem, a new classifier, Mexican Hat wavelet KELM classifier, is proposed in this paper. The proposed classifier successfully improves the training accuracy and reduces the training time in the multiclass classification problems. Moreover, the validity of the Mexican Hat wavelet as a kernel function of ELM is rigorously proved. Experimental results on different data sets show that the performance of the proposed classifier is significantly superior to the compared classifiers. PMID:28321249

  15. Mexican Hat Wavelet Kernel ELM for Multiclass Classification.

    PubMed

    Wang, Jie; Song, Yi-Fan; Ma, Tian-Lei

    2017-01-01

    Kernel extreme learning machine (KELM) is a novel feedforward neural network, which is widely used in classification problems. To some extent, it solves the existing problems of the invalid nodes and the large computational complexity in ELM. However, the traditional KELM classifier usually has a low test accuracy when it faces multiclass classification problems. In order to solve the above problem, a new classifier, Mexican Hat wavelet KELM classifier, is proposed in this paper. The proposed classifier successfully improves the training accuracy and reduces the training time in the multiclass classification problems. Moreover, the validity of the Mexican Hat wavelet as a kernel function of ELM is rigorously proved. Experimental results on different data sets show that the performance of the proposed classifier is significantly superior to the compared classifiers.

  16. Development and validation of a short version of the Partnership Self-Assessment Tool (PSAT) among professionals in Dutch disease-management partnerships.

    PubMed

    Cramm, Jane M; Strating, Mathilde Mh; Nieboer, Anna P

    2011-06-30

    The extent to which partnership synergy is created within quality improvement programmes in the Netherlands is unknown. In this article, we describe the psychometric testing of the Partnership Self-Assessment Tool (PSAT) among professionals in twenty-two disease-management partnerships participating in quality improvement projects focused on chronic care in the Netherlands. Our objectives are to validate the PSAT in the Netherlands and to reduce the number of items of the original PSAT while maintaining validity and reliability. The Dutch version of the PSAT was tested in twenty-two disease-management partnerships with 218 professionals. We tested the instrument by means of structural equation modelling, and examined its validity and reliability. After eliminating 14 items, the confirmatory factor analyses revealed good indices of fit with the resulting 15-item PSAT-Short version (PSAT-S). Internal consistency as represented by Cronbach's alpha ranged from acceptable (0.75) for the 'efficiency' subscale to excellent for the 'leadership' subscale (0.87). Convergent validity was provided with high correlations of the partnership dimensions and partnership synergy (ranged from 0.512 to 0.609) and high correlations with chronic illness care (ranged from 0.447 to 0.329). The psychometric properties and convergent validity of the PSAT-S were satisfactory rendering it a valid and reliable instrument for assessing partnership synergy and its dimensions of partnership functioning.

  17. A second case of Gerstmann-Sträussler-Scheinker disease linked to the G131V mutation in the prion protein gene in a Dutch patient.

    PubMed

    Jansen, Casper; Parchi, Piero; Capellari, Sabina; Strammiello, Rosaria; Dopper, Elise G P; van Swieten, John C; Kamphorst, Wouter; Rozemuller, Annemieke J M

    2011-08-01

    A rare case of Gerstmann-Sträussler-Scheinker disease in a 36-year-old Dutch man is reported. The clinical phenotype was characterized by slowly progressive cognitive decline, later followed by ataxia and parkinsonism. Neuropathologic findings consisted of numerous amyloid plaques in the cerebellum, which showed positive staining for the abnormal prion protein (PrP(Sc)). In addition, there were tau accumulations around numerous amyloid deposits in the cerebral cortex, striatum, hippocampal formation, and midbrain. There was no spongiform degeneration. Western blot analysis showed the co-occurrence of 2 distinct abnormal prion protein species comprising an unglycosylated, protease-resistant fragment of approximately 8 kd, which was found to be truncated at both N- and C-terminal ends by epitope mapping, and a detergent-insoluble but protease-sensitive form of full-length PrP(Sc). Sequence analysis disclosed a mutation at codon 131 of the prion protein gene (PRNP), resulting in a valine-for-glycine substitution (G131V). The patient was heterozygous at the polymorphic codon 129 and carried the mutation on the methionine allele. To our knowledge, this is the second family worldwide in which this mutation has been identified. Gerstmann-Sträussler-Scheinker disease should be considered in patients with a clinical diagnosis of familial frontotemporal dementia.

  18. Development and validation of a short version of the Partnership Self-Assessment Tool (PSAT) among professionals in Dutch disease-management partnerships

    PubMed Central

    2011-01-01

    Background The extent to which partnership synergy is created within quality improvement programmes in the Netherlands is unknown. In this article, we describe the psychometric testing of the Partnership Self-Assessment Tool (PSAT) among professionals in twenty-two disease-management partnerships participating in quality improvement projects focused on chronic care in the Netherlands. Our objectives are to validate the PSAT in the Netherlands and to reduce the number of items of the original PSAT while maintaining validity and reliability. Methods The Dutch version of the PSAT was tested in twenty-two disease-management partnerships with 218 professionals. We tested the instrument by means of structural equation modelling, and examined its validity and reliability. Results After eliminating 14 items, the confirmatory factor analyses revealed good indices of fit with the resulting 15-item PSAT-Short version (PSAT-S). Internal consistency as represented by Cronbach's alpha ranged from acceptable (0.75) for the 'efficiency' subscale to excellent for the 'leadership' subscale (0.87). Convergent validity was provided with high correlations of the partnership dimensions and partnership synergy (ranged from 0.512 to 0.609) and high correlations with chronic illness care (ranged from 0.447 to 0.329). Conclusion The psychometric properties and convergent validity of the PSAT-S were satisfactory rendering it a valid and reliable instrument for assessing partnership synergy and its dimensions of partnership functioning. PMID:21714931

  19. Preliminary Process Design of ITER ELM Coil Bracket Brazing

    NASA Astrophysics Data System (ADS)

    LI, Xiangbin; SHI, Yi

    2015-03-01

    With the technical requirement of the International Thermonuclear Experimental Reactor (ITER) project, the manufacture and assembly technology of the mid Edge Localized Modes (ELM) coil was developed by the Institute of Plasma Physics, Chinese Academy of Science (ASIPP). As the gap between the bracket and the Stainless Steel jacketed and Mineral Insulated Conductor (SSMIC) can be larger than 0.5 mm instead of 0.01 mm to 0.1 mm as in normal industrial cases, the process of mid ELM coil bracket brazing to the SSMICT becomes quiet challenging, from a technical viewpoint. This paper described the preliminary design of ELM coil bracket brazing to the SSMIC process, the optimal bracket brazing curve and the thermal simulation of the bracket furnace brazing method developed by ANSYS. BAg-6 foil (Bag50Cu34Zn16) plus BAg-1a paste (Bag45CuZnCd) solders were chosen as the brazing filler. By testing an SSMICT prototype, it is shown that the average gap between the bracket and the SSMIC could be controlled to 0.2-0.3 mm, and that there were few voids in the brazing surface. The results also verified that the preliminary design had a favorable heat conducting performance in the bracket.

  20. Edge Stability in ELM-free QH and RMP Plasmas

    NASA Astrophysics Data System (ADS)

    Snyder, P. B.; Burrell, K. H.; Chu, M. S.; Osborne, T. H.; Wilson, H. R.; Konz, C.

    2006-10-01

    The peeling-ballooning model proposes that intermediate wavelength MHD instabilities cause edge localized modes (ELMs) and impose constraints on the pedestal height. In typical discharges, the pedestal goes unstable to coupled peeling-ballooning modes shortly before an ELM is observed. However, in ELM-free discharges, such as in the promising Quiescent (QH) and resonant magnetic perturbation (RMP) H-mode regimes, the edge collisionality is low, and the resulting large bootstrap current in the pedestal region drives kink/peeling modes (n˜,1-10). Both flows and the conducting wall have significant impact in this regime, and an edge localized resistive wall mode can be unstable. We present a theory for the occurrence of QH-mode, in which the observed edge harmonic oscillation (EHO) is a saturated low-n kink/peeling mode, which drives particle transport and allows a steady quiescent pedestal. In RMP discharges, we find that the imposed magnetic perturbation plays the role of the EHO, similarly allowing steady state quiescent discharges.

  1. Observations of ELM Magnetic Precursors and Harmonic Oscillations in NSTX

    NASA Astrophysics Data System (ADS)

    Kelly, F.; Frederickson, E.; Bell, R.; Tritz, K.; Takahashi, H.; Maingi, R.; NSTX Collaboration

    2011-10-01

    Recent experiments on NSTX have shown n=1 dominant and n=2 mode ELM magnetic precursors with mode frequency in the 30 to 90 kHz range. The growing magnetic oscillations measured with the NSTX high-n Mirnov diagnostic occurred simultaneous with the onset of the increase in fast D α signal. These bursts of dominantly n=1, some n=2 and fewer higher modes resemble the predictions of a model simulation of ELMs by T. Evans in which a feedback amplification mechanism causes explosive growth of the separatrix topology driven by thermoelectric currents in flux tubes connecting the divertor plates. The n=1 mode remained dominant as wall recycling was reduced with lithium conditioning and n=3 RMP was applied, suggesting the trigger mechanism remained the same. Sufficient lithium suppressed ELMs and made the occurrence of low-frequency, low-n Harmonics Oscillations (HOs) more frequent. The HOs are consistent with modes localized in the edge with the frequency of the n = 1 harmonic near the rotation frequency of the edge plasma. Work supported in part by US DOE contract no. DE-AC02-09CH11466.

  2. ELM suppression in helium plasmas with 3D magnetic fields

    DOE PAGES

    Evans, T. E.; Loarte, A.; Orlov, D. M.; ...

    2017-06-21

    Experiments in DIII-D, using non-axisymmetric magnetic perturbation fields in high-purity low toroidal rotation, 4He plasmas have resulted in Type-I edge localized mode (ELM) suppression and mitigation. Suppression is obtained in plasmas with zero net input torque near the L–H power threshold using either electron cyclotron resonant heating (ECRH) or balanced co- and counter-I p neutral beam injection (NBI) resulting in conditions equivalent to those expected in ITER's non-active operating phase. In low-power ECRH H-modes, periods with uncontrolled density and impurity radiation excursions are prevented by applying n = 3 non-axisymmetric magnetic perturbation fields. ELM suppression results from a reduction andmore » an outward shift of the electron pressure gradient peak compared to that in the high-power ELMing phase. Here, the change in the electron pressure gradient peak is primarily due to a drop in the pedestal temperature rather than the pedestal density.« less

  3. Effects of ELMs and disruptions on ITER divertor armour materials

    NASA Astrophysics Data System (ADS)

    Federici, G.; Zhitlukhin, A.; Arkhipov, N.; Giniyatulin, R.; Klimov, N.; Landman, I.; Podkovyrov, V.; Safronov, V.; Loarte, A.; Merola, M.

    2005-03-01

    This paper describes the response of plasma facing components manufactured with tungsten (macro-brush) and CFC to energy loads characteristic of Type I ELMs and disruptions in ITER, in experiments conducted (under an EU/RF collaboration) in two plasma guns (QSPA and MK-200UG) at the TRINITI institute. Targets were exposed to a series of repetitive pulses in QSPA with heat loads in a range of 1-2 MJ/m 2 lasting 0.5 ms. Moderate tungsten erosion, of less than 0.2 μm per pulse, was found for loads of ˜1.5 MJ/m 2, consistent with ELM erosion being determined by tungsten evaporation and not by melt layer displacement. At energy densities of ˜1.8 MJ/m 2 a sharp growth of tungsten erosion was measured together with intense droplet ejection. MK-200UG experiments were focused on studying mainly vapor plasma production and impurity transport during ELMs. The conditions for removal of thin metal deposits from a carbon substrate were characterized.

  4. ELM suppression in helium plasmas with 3D magnetic fields

    NASA Astrophysics Data System (ADS)

    Evans, T. E.; Loarte, A.; Orlov, D. M.; Grierson, B. A.; Knölker, M. M.; Lyons, B. C.; Cui, L.; Gohil, P.; Groebner, R. J.; Moyer, R. A.; Nazikian, R.; Osborne, T. H.; Unterberg, E. A.

    2017-08-01

    Experiments in DIII-D, using non-axisymmetric magnetic perturbation fields in high-purity low toroidal rotation, 4He plasmas have resulted in Type-I edge localized mode (ELM) suppression and mitigation. Suppression is obtained in plasmas with zero net input torque near the L-H power threshold using either electron cyclotron resonant heating (ECRH) or balanced co- and counter-I p neutral beam injection (NBI) resulting in conditions equivalent to those expected in ITER’s non-active operating phase. In low-power ECRH H-modes, periods with uncontrolled density and impurity radiation excursions are prevented by applying n  =  3 non-axisymmetric magnetic perturbation fields. ELM suppression results from a reduction and an outward shift of the electron pressure gradient peak compared to that in the high-power ELMing phase. The change in the electron pressure gradient peak is primarily due to a drop in the pedestal temperature rather than the pedestal density.

  5. Imaging divertor strike point splitting in RMP ELM suppression experiments

    NASA Astrophysics Data System (ADS)

    Moyer, R. A.; Bykov, I.; Orlov, D. M.; Lee, J. S.; Evans, T. E.; Nazikian, R.; Makowski, M.; Lasnier, C. S.; Wang, H.; Abrams, T.; Watkins, J. G.

    2016-10-01

    Fast visible imaging of the lower divertor has been implemented at DIII-D to study the structure and dynamics of lobes induced by 3D fields in RMP ELM suppression experiments. The sharpest imaging was obtained with spatially localized molecular D2 emission indicative of the D flux to the surface. Multiple D2 emission peaks are readily resolved during RMPs, in contrast to the heat flux profile (from IR), which often shows little structure. The brightest D2 lobe is often farthest from the primary inner strike point (ISP). Mitigated ELMs perturb the position and intensity of the ISP lobes and spread the outer strike point emission into the far SOL, where it may be caused by ELM filament propagation. RMP current ramps affect the lobe locations and separations. Implications of the lobe dynamics for plasma response is being studied. Work supported by U.S. DOE under Grants DE-FG02-07ER54917 and DE-FG02-05ER54809, and Contracts DE-FC02-04ER54698, DE-AC52-07NA27344, DE-AC04-94AL85000, DE-AC05-06OR23100 and DE-AC02-09CH11466.

  6. Coupled simulation of kinetic pedestal growth and MHD ELM crash

    SciTech Connect

    Park, G.; Cummings, J.; Chang, C. S.; Klasky, Scott A; Ku, S.; Podhorszki, Norbert; Pankin, A.; Samtaney, Ravi; Shoshani, A.; Snyder, P.; Strauss, H.; Sugiyama, L.; CPES Team, the

    2007-01-01

    Edge pedestal height and the accompanying ELM crash are critical elements of ITER physics yet to be understood and predicted through high performance computing. An entirely self-consistent first principles simulation is being pursued as a long term research goal, and the plan is planned for completion in time for ITER operation. However, a proof-of-principle work has already been established using a computational tool that employs the best first principles physics available at the present time. A kinetic edge equilibrium code XGC0, which can simulate the neoclassically dominant pedestal growth from neutral ionization (using a phenomenological residual turbulence diffusion motion superposed upon the neoclassical particle motion) is coupled to an extended MHD code M3D, which can perform the nonlinear ELM crash. The stability boundary of the pedestal is checked by an ideal MHD linear peeling-ballooning code, which has been validated against many experimental data sets for the large scale (type I) ELMs onset boundary. The coupling workflow and scientific results to be enabled by it are described.

  7. Coupled simulation of kinetic pedestal growth and MHD ELM crash

    SciTech Connect

    Park, G-Y; Cummings, J.; Chang, C S; Podhorszki, Norbert; Klasky, Scott A; Ku, S.; Pankin, A.; Samtaney, Ravi; Shoshani, A.; Snyder, P.; Sugiyama, L.

    2009-01-01

    Edge pedestal height and the accompanying ELM crash are critical elements of ITER physics yet to be understood and predicted through high performance computing. An entirely self-consistent first principles simulation is being pursued as a long term research goal, and the plan is planned for completion in time for ITER operation. However, a proof-of-principle work has already been established using a computational tool that employs the best first principles physics available at the present time. A kinetic edge equilibrium code XGC0, which can simulate the neoclassically dominant pedestal growth from neutral ionization (using a phenomenological residual turbulence diffusion motion superposed upon the neoclassical particle motion) is coupled to an extended MHD code M3D, which can perform the nonlinear ELM crash. The stability boundary of the pedestal is checked by an ideal MHD linear peeling-ballooning code, which has been validated against many experimental data sets for the large scale (type I) ELMs onset boundary. The coupling workflow and scientific results to be enabled by it are described.

  8. PROGRESS IN THE PEELING-BALLOONING MODEL OF ELMS: NUMERICAL STUDIES OF 3D NONLINEAR ELM DYNAMICS

    SciTech Connect

    SNYDER,P.B; WILSON,H.R; XU,X.Q

    2004-11-01

    Nonlinear simulations with the 3D electromagnetic two-fluid BOUT code are employed to study the dynamics of edge localized modes (ELMs) driven by intermediate wavelength peeling-ballooning modes. It is found that the early behavior of the modes is similar to expectations from linear, ideal peeling-ballooning mode theory, with the modes growing linearly at a fraction of the Alfven frequency. In the nonlinear phase, the modes grow explosively, forming a number of extended filaments which propagate rapidly from the outer closed flux region into the open flux region toward the outboard wall. Similarities to non-linear ballooning theory, as well as additional complexities are observed. Comparison to observations reveals a number of similarities. Implications of the simulations and proposals for the dynamics of the full ELM crash are discussed.

  9. Progress in the Peeling-Ballooning Model of ELMs: Numerical Studies of 3D Nonlinear ELM Dynamics

    SciTech Connect

    Snyder, P B; Wilson, H R; Xu, X Q

    2004-12-13

    Nonlinear simulations with the 3D electromagnetic two-fluid BOUT code are employed to study the dynamics of edge localized modes (ELMs) driven by intermediate wavelength peeling-ballooning modes. It is found that the early behavior of the modes is similar to expectations from linear, ideal peeling-ballooning mode theory, with the modes growing linearly at a fraction of the Alfven frequency. In the non-linear phase, the modes grow explosively, forming a number of extended filaments which propagate rapidly from the outer closed flux region into the open flux region toward the outer wall. Similarities to non-linear linear ballooning theory, as well as additional complexities are observed. Comparison to observations reveals a number of similarities. Implications of the simulations and proposals for the dynamics of the full ELM crash are discussed.

  10. NSTX ELM Pacing and L-H Threshold Experiments for ITER

    NASA Astrophysics Data System (ADS)

    Canik, J. M.; Maingi, R.; Sontag, A. C.; Gerhardt, S. P.; Kaye, S.; Bell, R. E.; Gates, D.; Goldston, R.; Leblanc, B. P.; Menard, J.; Park, J.-K.; Evans, T.; Osborne, T.; Sabbagh, S.; Unterberg, E. A.

    2009-11-01

    We present a summary of recent edge-localized mode (ELM) pacing and L-H power threshold (PLH) experiments performed in NSTX in support of ITER. ELM triggering using 3D magnetic perturbations was used to perform pacing during ELM-free H-modes induced by lithium conditioning, mitigating the impurity accumulation typically observed in these conditions. The waveform of the applied field has been tailored to provide high reliability triggering at frequencies of >60 Hz to reduce the average ELM size. ELM pacing was also performed using vertical position oscillations, with the ELM frequency increased to ˜30 Hz from a natural frequency of ˜15 Hz. PLH is reduced by ˜50% at low triangularity, and also decreased by ˜50% during discharge with thick lithium wall coatings. PLH was observed to increase strongly with plasma current during sustained H-modes. The influence of heating method, non-axisymmetric fields, and magnetic balance on PLH will be presented.

  11. QUANTITATIVE TESTS OF ELMS AS INTERMEDIATE N PEELING-BALOONING MODES

    SciTech Connect

    LAO,LL; SNYDER,PB; LEONARD,AW; OIKAWA,T; OSBORNE,TH; PETRIE,TW; FERRON,JR; GROEBNER,RJ; HORTON,LD; KAMADA,Y; MURAKAMI,M; SAARELMA,S; STJOHN,HE; TURNBULL,AD; WILSON,HR

    2003-03-01

    A271 QUANTITATIVE TESTS OF ELMS AS INTERMEDIATE N PEELING-BALOONING MODES. Several testable features of the working model of edge localized modes (ELMs) as intermediate toroidal mode number peeling-ballooning modes are evaluated quantitatively using DIII-D and JT-60U experimental data and the ELITE MHD stability code. These include the hypothesis that ELM sizes are related to the radial widths of the unstable MHD modes, the unstable modes have a strong ballooning character localized in the outboard bad curvature region, and ELM size generally becomes smaller at high edge collisionality. ELMs are triggered when the growth rates of the unstable MHD modes become significantly large. These testable features are consistent with many ELM observations in DIII-D and JT-60U discharges.

  12. Fast dynamics of type I and grassy ELMs in JT-60U

    NASA Astrophysics Data System (ADS)

    Kojima, A.; Oyama, N.; Sakamoto, Y.; Kamada, Y.; Urano, H.; Kamiya, K.; Fujita, T.; Kubo, H.; Aiba, N.; JT-60 Team

    2009-11-01

    In order to understand the physics of the ELM trigger and determine the ELM size, the fast ELM dynamics of type I and grassy ELMs have been studied in JT-60U, using new fast diagnostics with high spatial and temporal resolutions such as a lithium beam probe (Δt ~ 0.5 ms) and a charge exchange recombination spectroscopy (Δt ~ 2.5 ms), which can measure the electron density and the ion temperature, respectively. The evolution of the ion pressure profile in the pedestal region has been evaluated for the first time by detailed edge profile measurements. Then, the dynamics of the density, the ion temperature and the ion pressure in the ELM cycle has been investigated. The co-rotating plasmas are compared with the counter (ctr)-rotating plasmas for the understanding of the toroidal rotation effects. Type I ELMs observed in co-rotating plasmas exhibit a larger and wider ELM affected area (Δnped/nped ~ 30%, radial extent >15 cm) than ctr-rotating plasmas (Δnped/nped ~ 20%, radial extent ~10 cm). Just before a type I ELM crash, the pedestal ion pressure and its maximum gradient in co-rotating plasmas are 20% and 12% higher than those in ctr-rotating plasmas, respectively. It is found that the radial extent of the ion pressure gradient at the pedestal region in co-rotating plasmas is 14% wider than that in ctr-rotating plasmas. The experimental results suggest that the ELM size is connected with the structure of the plasma pressure in the whole pedestal region. As for the dynamics of grassy ELMs, the collapse of density pedestal is smaller (<20%) and narrower (~5 cm) than those of type I ELMs, as observed in the collapse of the electron temperature pedestal. Thus, it is confirmed that both conductive and convective losses due to grassy ELMs are small.

  13. VizieR Online Data Catalog: The ELM survey. VII. 15 new ELM white dwarf cand. (Brown+, 2016)

    NASA Astrophysics Data System (ADS)

    Brown, W. R.; Gianninas, A.; Kilic, M.; Kenyon, S. J.; Allende Prieto, C.

    2016-05-01

    We present observations of 15 new extremely low-mass white dwarf (ELM WD) candidates. Ten objects are selected by color for our targeted spectroscopic ELM Survey program as described in Brown et al. (2012ApJ...744..142B). Five objects come from follow-up spectroscopy of the completed Hypervelocity Star survey. We acquire spectra for the 15 ELM WD candidates using the Blue Channel spectrograph on the 6.5m MMT telescope. We configured the Blue Channel spectrograph to obtain 3650-4500Å spectral coverage with 1.0Å spectral resolution. We acquire additional spectra for 5 objects using the KOSMOS spectrograph on the Kitt Peak National Observatory 4m Mayall telescope on program numbers 2014B-0119 and 2015A-0082. We configured the KOSMOS spectrograph to obtain 3500-6200Å spectral coverage with 2.0Å spectral resolution. We also acquire spectra for objects with g<17mag using the FAST spectrograph on the Fred Lawrence Whipple Observatory 1.5m Tillinghast telescope. We configured the FAST spectrograph to obtain 3500-5500Å spectral coverage with 1.7Å spectral resolution. (3 data files).

  14. Identification of characteristic ELM evolution patterns with Alfven-scale measurements and unsupervised machine learning analysis

    NASA Astrophysics Data System (ADS)

    Smith, David R.; Fonck, R. J.; McKee, G. R.; Diallo, A.; Kaye, S. M.; Leblanc, B. P.; Sabbagh, S. A.

    2016-10-01

    Edge localized mode (ELM) saturation mechanisms, filament dynamics, and multi-mode interactions require nonlinear models, and validation of nonlinear ELM models requires fast, localized measurements on Alfven timescales. Recently, we investigated characteristic ELM evolution patterns with Alfven-scale measurements from the NSTX/NSTX-U beam emission spectroscopy (BES) system. We applied clustering algorithms from the machine learning domain to ELM time-series data. The algorithms identified two or three groups of ELM events with distinct evolution patterns. In addition, we found that the identified ELM groups correspond to distinct parameter regimes for plasma current, shape, magnetic balance, and density pedestal profile. The observed characteristic evolution patterns and corresponding parameter regimes suggest genuine variation in the underlying physical mechanisms that influence the evolution of ELM events and motivate nonlinear MHD simulations. Here, we review the previous results for characteristic ELM evolution patterns and parameter regimes, and we report on a new effort to explore the identified ELM groups with 2D BES measurements and nonlinear MHD simulations. Supported by U.S. Department of Energy Award Numbers DE-SC0001288 and DE-AC02-09CH11466.

  15. Important role of pedestal ion temperature in the ELM mitigation by supersonic molecular beam injection

    NASA Astrophysics Data System (ADS)

    Ma, Q.; Yu, D. L.; Chen, C. Y.; Wei, Y. L.; Zhong, W. L.; Zou, X. L.; Zuo, H. Y.; Du, J. L.; Liu, L.; Dong, C. F.; Shi, Z. B.; Zhao, K. J.; Feng, B. B.; Zhou, Y.; Wang, Z. H.; Xu, M.; Liu, Yi; Yan, L. W.; Yang, Q. W.; Yao, L. H.; Ding, X. T.; Dong, J. Q.; Duan, X. R.; Liu, Yong; HL-2A Team

    2016-12-01

    Edge localized mode (ELM) is successfully mitigated by helium and deuterium supersonic molecular beam injections (SMBIs) on HL-2A. During the ELM mitigation by SMBIs, gradients of ion temperature (T i) and electron density are softened in the pedestal. It has been observed that the averaged gradient of the T i decreases around 44% and the well depth of radial electric field (E r) is reduced by the SMBI during ELM mitigation. Furthermore, at least 20% decrements of T i have to be attained to achieve a noticeable increase (decrease) of the ELM frequency (amplitude). In addition, the duration of ELM mitigation with helium SMBI is much longer than that with deuterium, likely due to the higher level of recycling neutral gas compared to that of deuterium; in the case of ELM mitigation by helium SMBI, the recovery duration of the density gradient is much shorter (10-20 ms) than that of T i (up to 40 ms or longer), indicating the importance of the T i in the ELM mitigation by SMBI. Finally, it has been observed that the T i is reduced before the beginning of the ELM mitigation, suggesting that the mechanism of the ELM mitigation by SMBI is closely related to the cooling effect.

  16. Confinement and ELM characteristics of H-mode plasmas in KSTAR

    NASA Astrophysics Data System (ADS)

    Ahn, J.-W.; Kim, H.-S.; Park, Y. S.; Terzolo, L.; Ko, W. H.; Park, J.-K.; England, A. C.; Yoon, S. W.; Jeon, Y. M.; Sabbagh, S. A.; Bae, Y. S.; Bak, J. G.; Hahn, S. H.; Hillis, D. L.; Kim, J.; Kim, W. C.; Kwak, J. G.; Lee, K. D.; Na, Y. S.; Nam, Y. U.; Oh, Y. K.; Park, S. I.

    2012-11-01

    The latest results of confinement and edge-localized mode (ELM) characteristics of Korea Superconducting Tokamak Advanced Research (KSTAR) H-mode plasmas are reported. The estimation of fast ion contribution to the total stored energy, calculated by both the NUBEAM and ASTRA simulations, and of the effective total heating power is used to derive the thermal energy confinement time (τE,thermal), which is compared with a multi-machine database. The measured power threshold for the L-H transition (Pthr) as a function of density shows a roll-over with minimum value at \\bar{n}_e \\sim 2\\times 10^{19}\\,m^{-3} . KSTAR H-mode plasmas exhibit three distinctive types of ELMs: large type-I ELMs, intermediate ELMs and a mixed (type-I and small ELM peaks) ELM regime. Power scans show that the frequency of the large ELMs increases with increasing heating power, a feature of type-I ELMs. The quality of confinement is higher for type-I and mixed ELMy H-mode (H98(y,2) ˜ 0.9-1) than for the intermediate ELM regime (H98(y,2) ˜ 0.7). Type-I ELMs have precursor-like signals from the magnetics measurement, while the other two ELM types do not. The low-field side (LFS) profile of electron temperature (Te), from the ECE measurement, and the pedestal profile of the toroidal velocity (Vt), from charge-exchange spectroscopy, show a continuous build up on the LFS during the inter-ELM period. However, the pedestal ion temperature (Ti) remains unchanged for most of the inter-ELM period until it rapidly rises in the last stage of the ELM cycle (⩾70-80%). The estimated electron pedestal collisionality for a type-I ELMy regime is v_e^\\ast \\sim 0.5{{--}}0.6 . The confinement and ELM characteristics for the ELM suppression discharges by the application of an n = 1 magnetic perturbation (MP) have also been investigated for each of the identified stages during the MP application. A second L-H transition during the L-mode phase after the end of first H-mode stage occurs for some discharges

  17. Resistance to Antibiotics and Antifungal Medicinal Products: Can Complementary and Alternative Medicine Help Solve the Problem in Common Infection Diseases? The Introduction of a Dutch Research Consortium

    PubMed Central

    Kok, Esther T.; Jong, Miek C.; Gravendeel, Barbara; Van Leeuwen, Willem B.; Baars, Erik W.

    2015-01-01

    The increase of antibiotic resistance worldwide, rising numbers of deaths and costs associated with this, and the fact that hardly any new antimicrobial drugs have been developed during the last decade have increased the interest in Complementary and Alternative Medicine (CAM) therapeutic interventions, if proven safe and effective. Observational studies on clinical CAM practices demonstrate positive effects of treatment of infections with CAM therapies (clinical effects, patient satisfaction) in combination with small percentages of antibiotics prescription. However, Cochrane reviews and other studies demonstrate that in most instances the quality of clinical trials on CAM treatment of infections is currently too low to provide sufficient evidence. Therefore a Dutch consortium on (in vitro and clinical) scientific research on CAM and antibiotic resistance has been formed. The aim and objective of the consortium is to establish an enduring partnership and to develop expertise to further develop and investigate safe and effective CAM treatments for infectious diseases of humans (and animals). A first ongoing project on the development of safe and effective biobased CAM antimycotics in women with (recurrent) vaginal candidiasis infection is introduced. PMID:26539227

  18. Nonlinear interaction between edge-localized modes (ELMs) and edge turbulence during ELM-crash-suppression phase under n=1 RMP

    NASA Astrophysics Data System (ADS)

    Lee, Jaehyun; Yun, Gunsu; Choi, Minjun; Kwon, Jae-Min; Jeon, Young-Mu; Lee, Woochang; Luhmann, Neville C., Jr.; Park, Hyeon K.

    2016-10-01

    Mutual interactions between edge-localized modes (ELMs) and turbulent eddies have been investigated in 2-D by using the KSTAR electron cyclotron emission imaging (ECEI) system. ECEI shows that ELM filaments still exist in the edge when the usual large scale collapse of the edge pedestal, i.e., the ELM crash, is completely suppressed by n = 1 resonant magnetic perturbation (RMP). Correlation analysis among ECEI channels reveals that the RMP enhances turbulent fluctuations in the edge and that ELM crashes are suppressed when the RMP exceeds a certain threshold. The spectral power distribution of turbulence shows a clear dispersion for a wide range of wavenumber (kθ < 1 cm-1) and frequency (f < 70 kHz). The radial velocity and ECE intensity fluctuations of the turbulent eddies are approximately in-phase and thus the turbulence involves a net radial energy transport. Bispectral analysis indicates the coexisting ELMs and turbulent eddies nonlinearly interact with each other. Both the enhancement of radial transport and the nonlinear interaction with ELMs may be the key to the physics mechanism of ELM-crash-suppression by low-n RMP. This work was supported by National Research Foundation of Korea under Grant No. NRF-2014M1A7A1A03029865 and NRF-2014M1A7AA03029881.

  19. High prevalence of autoimmune disease in the rare inflammatory bone disorder sternocostoclavicular hyperostosis: survey of a Dutch cohort.

    PubMed

    Valkema, Pieter A; Luymes, Clare H; Witteveen, Janneke E; le Cessie, Saskia; Appelman-Dijkstra, Natasha M; Hogendoorn, Pancras C W; Hamdy, Neveen A T

    2017-01-25

    Sternocostoclavicular hyperostosis (SCCH; ORPHA178311) is a rare inflammatory disorder of the axial skeleton, the precise pathophysiology of which remains to be established. We addressed the potential association of SCCH with autoimmune processes by evaluating the lifetime prevalence of autoimmune disease in 70 patients with adult-onset SCCH and 518 SCCH-unaffected first-degree relatives (parents, siblings and children). Danish hospital registry data for autoimmune diseases were used as reference data. The mean age of interviewed patients was 56.3 years (range 26-80 years) and 86% were female. Interviewed patients belonged to 63 families, with four families having clusters of 2-3 patients. A diagnosis of at least one autoimmune disease was reported in 20 SCCH patients (29%) and in 47 relatives (9.1%), compared to an estimated 3.9% prevalence of autoimmune disease in the Danish reference population. A diversity of autoimmune diseases was reported in SCCH patients and relatives, most frequently psoriasis vulgaris (14%). Palmoplantar pustulosis was reported by 28 patients (40%). In SCCH patients, inclusion of palmoplantar pustulosis as putative autoimmune disease increased the overall prevalence to 54%. The high prevalence of autoimmune disease in patients with sternocostoclavicular hyperostosis and their first-degree relatives suggests that autoimmunity may play a role in the still elusive pathophysiology of the intriguing osteogenic response to inflammation observed in this rare bone disorder.

  20. Latest investigations on fluctuations, ELM filaments and turbulent transport in the SOL of ASDEX Upgrade

    NASA Astrophysics Data System (ADS)

    Müller, H. W.; Adamek, J.; Cavazzana, R.; Conway, G. D.; Fuchs, C.; Gunn, J. P.; Herrmann, A.; Horaček, J.; Ionita, C.; Kallenbach, A.; Kočan, M.; Maraschek, M.; Maszl, C.; Mehlmann, F.; Nold, B.; Peterka, M.; Rohde, V.; Schweinzer, J.; Schrittwieser, R.; Vianello, N.; Wolfrum, E.; Zuin, M.; ASDEX Upgrade Team

    2011-07-01

    This paper presents turbulence investigations in the scrape-off layer (SOL) of ASDEX Upgrade in ohmic, L-mode and H-mode discharges using electrostatic and electromagnetic probes. Detailed studies are performed on small scale turbulence and on ELM filaments. Simultaneous measurements of floating and plasma potential fluctuations revealed significant differences between these quantities. Large errors can occur when the electric field is extracted from floating potential measurements, even in ohmic discharges. Turbulence studies in ohmic plasmas show the existence of density holes inside the separatrix and blobs outside. Close to the separatrix a reversal of the poloidal blob propagation velocity occurs. Investigations on the Reynolds stress in the scrape-off layer (SOL) show its importance for the momentum transport in L-mode while its impact for momentum transport during ELMs in H-mode is rather small. In the far SOL the electron density and temperature were measured during type-I ELMy H-mode at ASDEX Upgrade resolving ELM filaments. Strong density peaks and temperatures of several 10 eV were detected during the ELM events. Additional investigations on the ions in ELM filaments by a retarding field analyser indicate ion temperatures of 50-80 eV. ELMs also expel current concentrated in filaments into the SOL. Furthermore, discharges with small ELMs were studied. In N2 seeded discharges the type-I ELM frequency rises and the ELM duration decreases. For discharges with small type-II ELMs the mean turbulent radial particle flux is increased over the mean particle flux in type-I ELM discharges at otherwise similar plasma parameters.

  1. Impact of a pulsed supersonic deuterium gas jet on the ELM behaviour in ASDEX Upgrade

    NASA Astrophysics Data System (ADS)

    Lang, P. T.; Neuhauser, J.; Bucalossi, J.; Chankin, A.; Coster, D. P.; Drube, R.; Dux, R.; Haas, G.; Horton, L. D.; Kalvin, S.; Kocsis, G.; Maraschek, M.; Mertens, V.; Rohde, V.; Rozhansky, V.; Schneider, R.; Senichenkov, I.; Veselova, I.; Wolfrum, E.; ASDEX Upgrade Team

    2005-09-01

    The possibility for pacing of type-I edge localized modes (ELMs) in H-mode plasmas by intermittent gas injection was investigated in ASDEX Upgrade as a possible alternative to, and in comparison with, ELM control by pellets. A Laval nozzle type molecular deuterium injector was used, delivering 1.7 ms long jets with up to about 1020D per pulse at a supersonic flow velocity of 2.2 km s-1. With a repetition rate of 2 Hz and a fast rise time of ap25 µs, comparable to typical ELM rise times, the injector seemed to be well-suited for single ELM trigger tests. When applied to H-mode discharges with a moderate type-I ELM frequency of 40-60 Hz, no prompt (<0.5 ms) ELM triggering could be achieved, in contrast to the experience with pellets. There was, however, clear evidence for a delayed effect in the form of an inverse correlation of the gas pulse amplitude with the time interval between the gas pulse and the next ELM. The apparent lack of prompt ELM triggering seems to be due to a self-blocking of the gas jet by an extremely fast formation of a high density plasma layer in the separatrix vicinity, while the delayed effect may be simply caused by the jet-induced axisymmetric edge profile modification, similar to the delayed ELM cascade observed after a prompt ELM in case of large pellet injection. The delayed trigger effect observed might still be useful for ELM control in future machines, but the related high gas fuelling at elevated pulse frequency could make it unattractive in view of overall plasma performance.

  2. Pacing control of sawtooth and ELM oscillations in tokamaks

    NASA Astrophysics Data System (ADS)

    Lauret, M.; Lennholm, M.; de Baar, M. R.; Heemels, W. P. M. H.

    2016-12-01

    In tokamak plasmas, the sawtooth oscillation (ST) and the edge-localized-mode (ELM) are characterized by a phase of a slow evolution of the plasma conditions, followed by a crash-like instability that resets the plasma conditions when certain criteria of the plasma conditions are satisfied. Typically, the crashes induce losses of heat and energetic particles and may also trigger secondary instabilities. As the amplitude of the crash-like perturbation scales with the period between two crashes, period control of these oscillations is important for operations of large fusion facilities such as ITER and DEMO. In several present-day experimental facilities, a pacing control algorithm has been successfully applied for controlling the sawtooth period and the ELM period. However, a formal analysis has been lacking so far, which therefore forms the objective of the present paper. For this purpose, a reset model for the sawtooth period is introduced and, after a proper transformation a nonlinear discrete-time system is obtained, which is used for the formal analysis of pacing control. By representing the model in a Lur’e (or Lurie) form, we can derive conditions under which global asymptotic stability of the closed-loop (pacing) period control system is guaranteed. Moreover, we will show that the controller exhibits inherent robustness for model uncertainties. We envision that the analytical results in the area of pacing control of the sawtooth are also applicable to pacing period control of the ELM oscillation period. The presented reset model also explains why in recent experiments the sawtooth period locks with a periodically modulated power.

  3. Impurity radiation and the theory of ELMs in a tokamak

    SciTech Connect

    Morozov, D.K.; Roitman, A.V.

    1994-11-01

    A modification of the theory proposed by Kukharkin, Osipenko, and Pogutse is presented. An account of impurity radiation allows the authors to explain the absence of ELMs in the VH-mode of operation, and their arising during the transition to the ordinary H-mode. It is demonstrated that the radiation, whose intensity and temperature dependence are functions of the base gas neutral atom concentration, plays an essential destabilizing role. In the VH-mode, when the neutral atom concentration is low, the flute mechanism of the instability is suppressed, the radiation does not play a substantial role, and the mode is stable. 4 refs., 2 figs.

  4. ELM Meets Urban Big Data Analysis: Case Studies

    PubMed Central

    Chen, Huajun; Chen, Jiaoyan

    2016-01-01

    In the latest years, the rapid progress of urban computing has engendered big issues, which creates both opportunities and challenges. The heterogeneous and big volume of data and the big difference between physical and virtual worlds have resulted in lots of problems in quickly solving practical problems in urban computing. In this paper, we propose a general application framework of ELM for urban computing. We present several real case studies of the framework like smog-related health hazard prediction and optimal retain store placement. Experiments involving urban data in China show the efficiency, accuracy, and flexibility of our proposed framework. PMID:27656203

  5. ELM Suppression and Pedestal Structure in I-Mode Plasmas

    NASA Astrophysics Data System (ADS)

    Walk, John

    2013-10-01

    The I-mode regime is characterized by the formation of a temperature pedestal and enhanced energy confinement (H98 up to 1.2), without an accompanying density pedestal or drop in particle transport. Unlike ELMy H-modes, I-mode operation appears to have naturally-occurring suppression of large ELMs in addition to its highly favorable scalings of pedestal structure (and therefore overall performance). Instead, continuous Weakly Coherent Modes help to regulate density. Extensive study of the ELMy H-mode has led to the development of the EPED model, which utilizes calculations of coupled peeling-ballooning MHD modes and kinetic-ballooning mode (KBM) stability limits to predict the pedestal structure preceding an ELM crash. We apply similar tools to the structure and ELM stability of I-mode pedestals. Peeling-ballooning MHD calculations are completed using the ELITE code, showing I-mode pedestals to be generally MHD-stable. Under certain conditions, intermittent ELMs are observed in I-mode at reduced field, typically triggered by sawtooth crashes; modification of the temperature pedestal (and therefore the pressure profile stability) by sawtooth heat pulses is being examined in ELITE. Modeled stability to KBM turbulence in I-mode and ELMy H-mode suggests that typical I-modes are stable against KBM turbulence. Measured I-mode pedestals are significantly wider (more stable) than the width scaling with the square root of poloidal beta characteristic of the KBM-limited pedestals in ELMy H-mode. Finally, we explore scalings of pedestal structure with engineering parameters compared to ELMy H-modes on C-Mod. In particular, we focus on scalings of the pressure pedestal with heating power (and its relation to the favorable scaling of confinement with power in I-mode) and on relationships between heat flux and pedestal temperature gradients. This work is supported by DOE agreement DE-FC02-99ER54512. Theory work at General Atomics is supported by DOE agreement DE-FG02-99ER54309.

  6. Prevalence and determinants of non-alcoholic fatty liver disease in lifelines: A large Dutch population cohort

    PubMed Central

    Schreuder, Tim C. M. A.; Dullaart, Robin P. F.; Faber, Klaas Nico; Alizadeh, Behrooz Z.; Blokzijl, Hans

    2017-01-01

    Background & aims Non-alcoholic fatty liver disease is an increasing health issue that develops rather unnoticed with obesity, type 2 diabetes mellitus and metabolic syndrome. We investigated prevalence, determinants and associated metabolic abnormalities of non-alcoholic fatty liver disease in the largest population-based cohort to date. Methods Biochemical characteristics, type 2 diabetes mellitus and metabolic syndrome were determined in the Lifelines Cohort Study (N = 167,729), a population-based cohort in the North of the Netherlands. Non-alcoholic fatty liver disease was defined as Fatty Liver Index (FLI)≥60. Exclusion criteria were age <18 years, immigrants, missing data to assess FLI and metabolic syndrome, excessive alcohol use, previous-diagnosed hepatitis or cirrhosis and non-fasting blood sampling. Results Out of 37,496 included participants (median age 44 years, 62.1% female), 8,259 (22.0%) had a FLI≥60. Individuals with a FLI≥60 were more often male, older, obese, had higher levels of hemoglobinA1c, fasting glucose, liver enzymes, total cholesterol, low-density lipoprotein cholesterol, triglycerides, c-reactive protein and leucocytes and lower high-density lipoprotein cholesterol (all P<0.0001). Participants with a FLI≥60 showed higher prevalence of type 2 diabetes mellitus (9.3% vs. 1.4%), metabolic syndrome (54.2% vs. 6.2%), impaired renal function (20.1% vs. 8.7%) and cardiovascular disease (4.6% vs. 1.6%) (all P<0.0001). Multivariable logistic analysis showed that smoking, hemoglobin, leucocytes, c-reactive protein, platelets, alanine aminotransferase, alkaline phosphatase, albumin, impaired renal function (OR 1.27, 95%CI 1.15–1.41), metabolic syndrome (OR 11.89, 95%CI 11.03–12.82) and its individual components hyperglycemia (OR 2.53, 95%CI 2.34–2.72), hypertension (OR 1.89, 95%CI 1.77–2.01) and reduced high-density lipoprotein cholesterol (OR 3.44, 95%CI 3.22–3.68) were independently associated with suspected non-alcoholic fatty

  7. Strengthening infectious disease surveillance in a Dutch-German crossborder area using a real-time information exchange system.

    PubMed

    ter Waarbeek, Henriëtte; Hoebe, Christian; Freund, Hermann; Bochat, Verena; Kara-Zaïtr, Chakib

    2011-06-01

    International outbreaks are occurring much faster than before and require rapid trans-national detection and response. Never before has there been a more urgent need for improved crossborder collaboration on harmonisation of surveillance and response systems despite varying legislations. In the Euregion Maas Rhine, the Public Health Services of South Limburg in the Netherlands and Aachen in Germany agreed to join forces to work on a collaborative tool for sharing real-time infectious disease data. Both units had already implemented an adapted version of HPZone (a web-based software suite for managing infectious diseases at the local level). The collaborative work was realised through finding solutions to five key challenges. First, Euregional disease protocols were agreed commensurate with national guidelines. Secondly, a minimal dataset for infectious disease exchange information was negotiated taking into consideration international health regulations and differences in legislation. Thirdly, a mature risk assessment model for infectious disease was augmented to account for transborder spread and Euregional impact. Fourthly, protocol alert rules were negotiated on triggers for early warning. Finally, a crossborder dashboard, as a component of HPVista and encapsulating the four previous deliverables into a secure web-based system, was developed. HPVista is the parent application to HPZone and enables wider incident command and control regionally, nationally and internationally. The dashboard has facilities for displaying what, when, where and how cases, contacts and outbreaks happen in the crossborder area. It also provides secure communications for further discussion and exchange of other key information not currently shared electronically. The collaborative work embedded in the modified HPZone and HPVista versions with real-time surveillance and geographical information system mapping readily facilitates the systematic analysis of crossborder health incidents in

  8. Co-occurence of Two Invasive Species: The Banded and European Elm Bark Beetles (Coleoptera: Scolytidae)

    USDA-ARS?s Scientific Manuscript database

    The invasive European elm bark beetle, Scolytus multistriatus (Marsham), was first detected a century ago and now occurs in most of the continental United States. The invasive banded elm bark beetle, Scolytus schevyrewi Semenov, native to Asia, was discovered in the United States in 2003 and is now...

  9. Toroidal mode number determination of ELM associated phenomena on ASDEX Upgrade

    NASA Astrophysics Data System (ADS)

    Mink, Felician; Wolfrum, Elisabeth; Maraschek, Marc; Zohm, Hartmut; Horváth, László; Laggner, Florian M.; Manz, Peter; Viezzer, Eleonora; Stroth, Ulrich; the ASDEX Upgrade Team

    2016-12-01

    In highly confined tokamak plasmas periodically appearing edge localized modes (ELMs) are accompanied by mode-like magnetohydrodynamic (MHD) activities with defined toroidal mode numbers. Here the method of determining toroidal mode numbers n on the ASDEX Upgrade tokamak with a toroidally spread magnetic pick-up coil array is reviewed and improved by taking into account intrinsic coil phases. ELM synchronization is used to characterize inter-ELM MHD activity and their development during the ELM cycle in terms of their mode numbers. The mode number development is correlated with the development of the pedestal parameters which shows that the inter-ELM modes cause transport across the pedestal. An estimation of the position of the modes is done via a comparison between the mode velocities and the plasma rotation profile at the edge. Results show that during the ELM cycle MHD modes appear at several positions in the strong gradient region with clearly defined toroidal structures in the range of n  =  1-10. These structures of inter-ELM modes are preserved during the ELM crash where also a strong n  =  0 phenomenon occurs.

  10. THE ELM SURVEY. III. A SUCCESSFUL TARGETED SURVEY FOR EXTREMELY LOW MASS WHITE DWARFS

    SciTech Connect

    Brown, Warren R.; Kenyon, Scott J.; Kilic, Mukremin; Allende Prieto, Carlos E-mail: skenyon@cfa.harvard.edu E-mail: callende@iac.es

    2012-01-10

    Extremely low mass (ELM) white dwarfs (WDs) with masses < 0.25 M{sub Sun} are rare objects that result from compact binary evolution. Here, we present a targeted spectroscopic survey of ELM WD candidates selected by color. The survey is 71% complete and has uncovered 18 new ELM WDs. Of the seven ELM WDs with follow-up observations, six are short-period binaries and four have merger times less than 5 Gyr. The most intriguing object, J1741+6526, likely has either a pulsar companion or a massive WD companion making the system a possible supernova Type Ia or an Ia progenitor. The overall ELM survey has now identified 19 double degenerate binaries with <10 Gyr merger times. The significant absence of short orbital period ELM WDs at cool temperatures suggests that common envelope evolution creates ELM WDs directly in short period systems. At least one-third of the merging systems are halo objects, thus ELM WD binaries continue to form and merge in both the disk and the halo.

  11. ELM-ART--An Interactive and Intelligent Web-Based Electronic Textbook

    ERIC Educational Resources Information Center

    Weber, Gerhard; Brusilovsky, Peter

    2016-01-01

    This paper present provides a broader view on ELM-ART, one of the first Web-based Intelligent Educational systems that offered a creative combination of two different paradigms--Intelligent Tutoring and Adaptive Hypermedia technologies. The unique dual nature of ELM-ART contributed to its long life and research impact and was a result of…

  12. Comparison of Small ELM Characteristics and Regimes in Alcator C-Mod, MAST, and NSTX

    SciTech Connect

    Maingi, Rajesh; Hubbard, A.E.; Meyer, H.; Kirk, A.; Maqueda, R.; Terry, J. L.

    2011-01-01

    We report on the status of a set of ITPA-coordinated experiments between the Alcator C-Mod, MAST and NSTX devices to compare the characteristics and access conditions of discharges with small edge-localized modes (ELMs). The small ELMs in C-Mod, MAST and one of the two small ELM types in NSTX exist when {beta}{sub ped}{sup pol} approached 10-15%, although the lower/upper limits of the operational windows differ. These small ELM regimes appear in diverted configurations very close to balanced double-null in each device. We classify these small ELMs as type II, based on the published characteristics from a number of previous studies. In addition, these type II ELMs in each device had multiple filaments with propagation in the co-I{sub p} or ion diamagnetic drift direction. Moreover, we conclude that these type II ELMs are distinct from the type V ELMs routinely observed in NSTX, which have one or two filaments and propagate in the electron diamagnetic drift direction.

  13. Biology of the invasive banded elm bark beetle (Coleoptera: Scolytidae) in the western United States

    Treesearch

    Jana C. Lee; Jose F. Negron; Sally J. McElwey; Livy Williams; Jeffrey J. Witcosky; John B. Popp; Steven J. Seybold

    2011-01-01

    The banded elm bark beetle, Scolytus schevyrewi Semenov (Coleoptera: Scolytidae), native to Asia, was detected in the United States in 2003, and as of 2011 it is known to occur in 28 states and four Canadian provinces. S. schevyrewi infests the same elm (Ulmus spp.) hosts as the longestablished invasive...

  14. ELM-ART--An Interactive and Intelligent Web-Based Electronic Textbook

    ERIC Educational Resources Information Center

    Weber, Gerhard; Brusilovsky, Peter

    2016-01-01

    This paper present provides a broader view on ELM-ART, one of the first Web-based Intelligent Educational systems that offered a creative combination of two different paradigms--Intelligent Tutoring and Adaptive Hypermedia technologies. The unique dual nature of ELM-ART contributed to its long life and research impact and was a result of…

  15. Use Correlation Coefficients in Gaussian Process to Train Stable ELM Models

    DTIC Science & Technology

    This paper proposes a new method to train stable extreme learning machines (ELM). The new method, called StaELM, uses correlation coefficients in...handle hidden layer outputs, using correlation coefficients can quantify the similarity of hidden layer outputs with real numbers in (0, 1] and avoid

  16. Structure, Stability and ELM Dynamics of the H-Mode Pedestal in DIII-D

    SciTech Connect

    Fenstermacher, M E; Leonard, A W; Osborne, T H; Snyder, P B; Thomas, D M; Boedo, J A; Casper, T A; Colchin, R J; Groebner, R J; Groth, M; Kempenaars, M H; Loarte, A; Saibene, G; VanZeeland, M A; Zeng, L; Xu, X Q

    2004-10-13

    Experiments are described that have increased understanding of the transport and stability physics that set the H-mode edge pedestal width and height, determine the onset of Type-I edge localized modes (ELMs), and produce the nonlinear dynamics of the ELM perturbation in the pedestal and scrape-off layer (SOL). Predictive models now exist for the n{sub e} pedestal profile and the p{sub e} height at the onset of Type-I ELMs, and progress has been made toward predictive models of the T{sub e} pedestal width and nonlinear ELM evolution. Similarity experiments between DIII-D and JET suggested that neutral penetration physics dominates in the relationship between the width and height of the n{sub e} pedestal while plasma physics dominates in setting the T{sub e} pedestal width. Measured pedestal conditions including edge current at ELM onset agree with intermediate-n peeling-ballooning (P-B) stability predictions. Midplane ELM dynamics data show the predicted (P-B) structure at ELM onset, large rapid variations of the SOL parameters, and fast radial propagation in later phases, similar to features in nonlinear ELM simulations.

  17. Impact of ELM filaments on divertor heat flux dynamics in NSTX

    SciTech Connect

    Ahn, J. -W.; Maingi, Rajesh; Canik, John M.; Gan, K. F.; Gray, Travis K.; McLean, A. G.

    2015-01-01

    In this study, the ELM induced change in wetted area (Awet) and peak heat flux (qpeak) of divertor heat flux is investigated as a function of the number of striations, which represent ELM filaments, observed in the heat flux profile in NSTX. More striations are found to lead to larger Awet and lower qpeak. The typical number of striations observed in NSTX is 0–9, while 10–15 striations are normally observed in other machines such as JET, and the ELM contracts heat flux profile when the number of striations is less than 3–4 but broadens it with more of them. The smaller number of striations in NSTX is attributed to the fact that NSTX ELMs are against kink/peeling boundary with lower toroidal mode number (n = 1–5), while typical peeling–ballooning ELMs have higher mode number of n = 10–20. For ELMs with smaller number of striations, relative Awet change is rather constant and qpeak change rapidly increases with increasing ELM size, while Awet change slightly increases leading to a weaker increase of qpeak change for ELMs with larger number of striations, both of which are unfavourable trend for the material integrity of divertor tiles.

  18. The Relationships Between ELM Suppression, Pedestal Profiles, and Lithium Wall Coatings in NSTX

    SciTech Connect

    D.P. Boyle, R. Maingi, P.B. Snyder, J. Manickam, T.H. Osborne, R.E. Bell, B.P. LeBlanc, and the NSTX Team

    2012-08-17

    Recently in the National Spherical Torus Experiment (NSTX), increasing lithium wall coatings suppressed edge localized modes (ELMs), gradually but not quite monotonically. This work details profile and stability analysis as ELMs disappeared throughout the lithium scan. While the quantity of lithium deposited between discharges did not uniquely determine the presence of ELMs, profile analysis demonstrated that lithium was correlated to wider density and pressure pedestals with peak gradients farther from the separatrix. Moreover, the ELMy and ELM-free discharges were cleanly separated by their density and pedestal widths and peak gradient locations. Ultimately, ELMs were only suppressed when lithium caused the density pedestal to widen and shift inward. These changes in the density gradient were directly reflected in the pressure gradient and calculated bootstrap current. This supports the theory that ELMs in NSTX are caused by peeling and/or ballooning modes, as kink/peeling modes are stabilized when the edge current and pressure gradient shift away from the separatrix. Edge stability analysis using ELITE corroborated this picture, as reconstructed equilibria from ELM-free discharges were generally farther from their kink/peeling stability boundaries than ELMy discharges. We conclude that density profile control provided by lithium is the key first step to ELM suppression in NSTX

  19. Theory and Modeling of ELMs and Constraints on the H-Mode Pedestal

    NASA Astrophysics Data System (ADS)

    Snyder, P. B.; Ferron, J. R.; Lao, L. L.; Leonard, A. W.; Osborne, T. H.; Turnbull, A. D.; Wilson, H. R.; Webster, A. J.; Xu, X. Q.; Mossessian, D.; Murakami, M.

    2002-11-01

    We present a theory of edge localized modes (ELMs) and constraints on the H-mode pedestal, based on the stability of intermediate wavelength peeling-ballooning modes driven by the strong pressure gradient and resulting bootstrap current in the pedestal region. Detailed studies of ideal MHD pedestal stability bounds are presented using the ELITE code, and are compared to data from multiple tokamaks. Observed ELM onset times and characteristics, as well as variation in pedestal behavior with discharge shape and collisionality, are studied. In addition, the impact of diamagnetic stabilization and rotation shear are assessed, and progress on dynamic modeling of the ELM cycle which couples transport codes to stability calculations and ELM crash models is briefly discussed. Nonlinear simulations using the BOUT code are used to provide further insight on non-ideal effects and ELM crash dynamics.

  20. Critical aspects of ELM crash suppression by magnetic perturbations in KSTAR

    NASA Astrophysics Data System (ADS)

    Kim, Jayhyun; Jeon, Y. M.; Park, G. Y.; Choi, M. J.; in, Y.; Yoon, S. W.; Bae, C.; Lee, J.; Park, J.-K.; Ahn, J.; The Kstar Team Team

    2016-10-01

    ELM crash suppressions have been achieved by low n (n = 1, 2, and mixture of them) magnetic perturbations (MPs) with using various configurations of in-vessel perturbation coils in KSTAR. So far, the suppressed periods are extended longer than 10 seconds. In KSTAR, the complete suppression of ELM crashes almost always accompany with the increase of edge fluctuations which are likely to be excited by applied MPs. The excitation of edge fluctuation exhibited the bifurcation-like feature depending on the strength of MPs. The conditions to excite edge fluctuations were investigated with including well known q95 window. On the other hand, ELM mitigation does not come with the increase of edge fluctuations. Instead, it seems that applied MPs directly trigger small frequent ELMs since the mitigated ELMs suddenly disappear when turning MPs off. The results stress the importance of stability analysis with the use of perturbed equilibrium since most stability studies have assumed unperturbed/undistorted equilibrium.

  1. Biology of the invasive banded elm bark beetle, Scolytus schevyrewi Semenov (Coleoptera: Scolytidae), in the western United States

    USDA-ARS?s Scientific Manuscript database

    The invasive banded elm bark beetle, Scolytus schevyrewi Semenov, native to Asia, was detected in the United States in 2003 and is now known to occur in 28 states and four Canadian Provinces. S. schevyrewi infests the same elm hosts as the long-established invasive, and smaller European elm bark be...

  2. Can the Non-linear Ballooning Model describe ELMs?

    NASA Astrophysics Data System (ADS)

    Henneberg, S. A.; Cowley, S. C.; Wilson, H. R.

    2015-11-01

    The explosive, filamentary plasma eruptions described by the non-linear ideal MHD ballooning model is tested quantitatively against experimental observations of ELMs in MAST. The equations describing this model were derived by Wilson and Cowley for tokamak-like geometry which includes two differential equations: the linear ballooning equation which describes the spatial distribution along the field lines and the non-linear ballooning mode envelope equation, which is a two-dimensional, non-linear differential equation which can involve fractional temporal-derivatives, but is often second-order in time and space. To employ the second differential equation for a specific geometry one has to evaluate the coefficients of the equation which is non-trivial as it involves field line averaging of slowly converging functions. We have solved this system for MAST, superimposing the solutions of both differential equations and mapping them onto a MAST plasma. Comparisons with the evolution of ELM filaments in MAST will be reported in order to test the model. The support of the EPSRC for the FCDT (Grant EP/K504178/1), of Euratom research and training programme 2014-2018 (No 633053) and of the RCUK Energy Programme [grant number EP/I501045] is gratefully acknowledged.

  3. The ELM Survey: Finding the Shortest Period Binary White Dwarfs

    NASA Astrophysics Data System (ADS)

    Canton, Paul; Gianninas, Alexandros; Kilic, Mukremin; Brown, Warren; Kenyon, Scott

    2014-08-01

    A new discovery space for short period binary white dwarfs has opened up with the availability of 14,600 deg^2 of SDSS Data Release 9 photometry. The Extremely Low-Mass (ELM) Survey takes advantage of this photometry and SDSS spectroscopy to identify compact systems with 1 hour or shorter orbital periods. To significantly increase the number of merging white dwarf systems known, we have proposed to obtain follow- up spectroscopic observations of all candidates with g ≤ 19 mag and photometric colors consistent with extremely low-mass (≤ 0.3 M_⊙) white dwarfs. Most of our 2012A Hale and 2012B KP 4m observing runs were lost to weather, yet we managed to identify at least one new short period binary. Our 2013A run on the KP 4m was successful in identifying many new ELM white dwarfs, and in our 2013B follow-up run we observed two new 3 hour binaries while also obtaining further data on a number of other merging systems. Here we propose to continue our program by observing our fall targets on the KP 4m telescope to constrain their binary orbital periods. Our two major science goals are to discover detached gravitational wave sources for fundamental tests of general relativity, and to constrain the formation rate and space density of merging white dwarfs. The latter is important for constraining the contribution of double degenerates to Type Ia and underluminous supernovae.

  4. A Fully Noninductive, ELM-Suppressed Scenario for ITER

    NASA Astrophysics Data System (ADS)

    Petty, C. C.; Petrie, T. W.; Nazikian, R.; Turco, F.; Lasnier, C.

    2016-10-01

    An attractive regime with beta, collisionality and plasma shape relevant to the ITER steady-state mission has been attained in DIII-D using the hybrid scenario, including complete ELM suppression using resonant magnetic perturbation (RMP) coils. Fully noninductive hybrids with simultaneous high beta (βN <= 3.1) and high confinement (H98 y 2 <= 1.4) have achieved zero surface loop voltage for up to two current relaxation times using efficient central current drive from ECCD and NBCD. This steady-state regime has been successfully integrated with ELM suppression by applying an odd parity n=3 RMP, which has only a minor impact on the pedestal pressure ( 15 %) and H98 y 2 ( 10 %) In radiating divertor experiments in hybrids, the combination of Argon seeding and strong Deuterium puffing more than doubles the plasma radiative power, up to 55% of the input power, with less than 10% increase in Zeff. IR camera measurements find that the peak heat flux in the upper, outer divertor falls by a factor of 2 (from 4.6 to 2.3 MW /m2). Work supported by USDOE under DE-FC02-04ER54698, DE-AC02-09CH11466, DE-FG02-04ER54761, and DE-AC52-07NA27344.

  5. The position of the Dutch Farmers' Union on lessons learned and future prevention and control of foot and mouth disease.

    PubMed

    Cuijpers, M P; Osinga, K J

    2002-12-01

    Foot and mouth disease (FMD) has devastated animal husbandry in The Netherlands frequently in the past and still constitutes a threat. The use of vaccination reduced the number of outbreaks in The Netherlands in the 20th Century. However, the desire of some member states of the European Community not to use vaccination led to a new strategy based on stamping-out of infected and contagious farms and to strict transportation regulations. In 2001, this proved very disruptive to the wider rural economy, such as the recreational and tourism sectors. The policy also caused severe animal welfare problems and psychological problems among farmers and their families. This raised questions about the wider, and not only veterinary or agricultural, implications of control strategies of foot and mouth disease virus (FMDV). The technology seems to be in place for a return to the use of protective vaccination against FMDV during an outbreak, provided the Office International des Epizooties (OIE: World organisation for animal health) and European Commission (EC) receive data that substantiate the reliability of differentiating tests such as the 3ABC enzyme-linked immunosorbent assay (ELISA) for use in individual animals. Research is in progress but may not be able to produce these data until 2003 or 2004. High potency vaccines should be used to elicit sufficient immunity within three to four days. During an FMD crisis, farmers should be assisted to find markets for products from areas affected by FMDV. The human dimension of any FMD outbreak must be dealt with sufficiently in any contingency plan.

  6. Paraoxonase (PON1) and the risk for coronary heart disease and myocardial infarction in a general population of Dutch women.

    PubMed

    van Himbergen, Thomas M; van der Schouw, Yvonne T; Voorbij, Hieronymus A M; van Tits, Lambertus J H; Stalenhoef, Anton F H; Peeters, Petra H M; Roest, Mark

    2008-08-01

    There is strong evidence from both animal- and in vitro-models that paraoxonase (PON1) is involved in the onset of cardiovascular disease. In humans there is no consensus on this issue and therefore we investigated the effect of PON1 genotype and activity on the incidence of coronary heart disease (CHD) and acute myocardial infarction (AMI) in a large prospective cohort of 17,357 middle-aged women. We applied a case-cohort design using the CHD (n=211) and AMI cases (n=71) and a random sample from the baseline cohort (n=1527). A weighted Cox proportional hazards model was used to estimate age- and multivariate-adjusted hazard ratios (HR) for the PON1 genetic variants (192Q > R and -107C > T) and tertiles of the PON1 arylesterase- and paraoxonase activities. Neither the PON1 genetic variants, nor the PON1 activities affected the incidence of CHD in general, but, an increased paraoxonase activity was associated with a higher risk of AMI: the second and third tertile HR were 1.31 and 2.07, respectively (P-trend=0.029, multivariate model). In the subgroup of never-smokers, paraoxonase activity was associated with an increased risk for AMI: the second and third tertile HR were 4.1 and 4.7, respectively (P-trend=0.009, multivariate model). Additionally, when compared to the lowest paraoxonase tertile in never-smokers, the highest paraoxonase tertile in current-smokers showed a 19.2-fold higher risk for AMI (95%CI: 5.3-69.5, P < 0.0001, multivariate model). In conclusion, this study shows that in middle-aged women paraoxonase activity was associated with an increased risk for AMI and that the risk was modified by the effects of smoking.

  7. Prosthetic valves in adult patients with congenital heart disease: Rationale and design of the Dutch PROSTAVA study.

    PubMed

    Freling, H G; van Slooten, Y J; van Melle, J P; Mulder, B J M; van Dijk, A P J; Hillege, H L; Post, M C; Sieswerda, G Tj; Jongbloed, M R M; Willems, T P; Pieper, P G

    2012-10-01

    Data on long-term complications in adult patients with congenital heart disease (ACHD) and a prosthetic valve are scarce. Moreover, the influence of prosthetic valves on quality of life (QoL) and functional outcome in ACHD patients with prosthetic valves has not been studied. The primary objective of the PROSTAVA study is to investigate the relation between prosthetic valve characteristics (type, size and location) and functional outcome as well as QoL in ACHD patients. The secondary objectives are to investigate the prevalence and predictors of prosthesis-related complications including prosthesis-patient mismatch. The PROSTAVA study, a multicentre cross-sectional observational study, will include approximately 550 ACHD patients with prosthetic valves. Primary outcome measures are maximum oxygen uptake during cardiopulmonary exercise testing and QoL. Secondary outcomes are the prevalence and incidence of valve-related complications including prosthesis-patient mismatch. Other evaluations are medical history, physical examination, echocardiography, MRI, rhythm monitoring and laboratory evaluation (including NT-proBNP). Identification of the relation between prosthetic valve characteristics in ACHD patients on one hand and functional outcome, QoL, the prevalence and predictors of prosthesis-related complications on the other hand may influence the choice of valve prosthesis, the indication for more extensive surgery and the indication for re-operation.

  8. H-mode and ELM Characteristics at Ultralow Aspect Ratio in the Pegasus Experiment

    NASA Astrophysics Data System (ADS)

    Fonck, R. J.; Barr, J. L.; Bongard, M. W.; Kriete, D. M.; Perry, J. M.; Reusch, J. A.; Thome, K. E.

    2016-10-01

    Operation at low BT and A < 1.3 allows access to the H-mode regime in the Pegasus experiment using only Ohmic heating. Modest plasma parameters in this regime permit detailed probe measurements of the edge pedestal region. H-mode plasmas have standard L-H transition phenomena: a drop in Dα radiation; formation of pressure and current pedestals; field-aligned filament ejection during ELMs; and a doubling of τE from H98 0.5 to 1 . The L-H power threshold PLH increases monotonically with ne, consistent with both the ITPA08 scaling, PITPA 08 , used for ITER and the theoretical FM3 power threshold model. Unlike at high A, PLH is comparable in limited and single-null diverted topologies at A 1.2 , consistent with FM3 predictions. PLH /PITPA 08 increases rapidly as A -> 1 , and is > 10 for A < 1.3 . Multiple- n modes are observed during ELMs, consistent with excitation of multiple peeling-ballooning modes. Small, Type-III-like ELMs occur at POH PLH with n <= 4 . Large, Type-I-like ELMs occur with POH >PLH and intermediate 5 < n < 15 . High-resolution spatiotemporal measurements of Jedge(R , t) across single ELMs show the nonlinear generation and expulsion of current-carrying filaments during the large ELM crash. Helical edge current injection appears to suppress small ELM activity. Work supported by US DOE Grant DE-FG02-96ER54375.

  9. Study of ELM Density Turbulence using the Upgraded Phase Contrast Imaging on DIII-D

    NASA Astrophysics Data System (ADS)

    Rost, J. C.; Davis, E. M.; Marinoni, A.; Porkolab, M.; Burrell, K. H.

    2016-10-01

    Recent studies of the turbulent density fluctuations accompanying ELMs in mixed ELM-type discharges have exploited the expanded wavenumber range of the upgraded Phase Contrast Imaging (PCI) diagnostic. The PCI data demonstrate the difference between the fluctuations generated by Type I ELMs, which are broadband in frequency and wavelength, and those generated by Type III ELMs, which are similar in amplitude but restricted to long wavelengths, suggesting that turbulence may play a significant role in Type I ELM transport. The high frequency response of PCI makes it ideal for studying the ELM-associated density fluctuations, which are observed at frequencies up to several MHz, evolve on time scales of 10s of μs, and persist after the magnetic component of the ELM has decayed away. The upgraded PCI, with independent systems for long and short wavelength detection (k < 5 cm-1 and 1 < k < 30 cm-1 respectively), demonstrated coverage of the full wavenumber range of interest. Work supported in part by the US Department of Energy under DE-FG02-94ER54235, DE-FC02-04ER54698, and DE-FC02-99ER54512.

  10. Calibration of Model for Tokamak H-mode Pedestal and ELMs

    NASA Astrophysics Data System (ADS)

    MacDonald, C.; Bateman, G.; Kritz, A. H.; McElhenny, J.; Osborne, T.; Pankin, A. Y.

    2004-11-01

    Experimental data is used to calibrate a model for the pedestal and Edge Localized Modes (ELMs) implemented in the ASTRA integrated code. The model is calibrated to predict the frequency of the ELMs and the height of the electron and ion temperature pedestals just before an ELM crash. Detailed comparisons are made with experimental data from the DIII-D 98889 discharge, in which the noise in the data is reduced by overlaying the plasma profiles from a sequence of consecutive, nearly identical ELM cycles. The model includes neoclassical transport and transport driven by ion drift modes, resistive ballooning modes, and the electron gradient temperature mode. The criterion for triggering ELM crashes allows for access to second stability. The calibration is carried out by adjusting: (1) The flow shear rates for individual modes of long wavelength turbulent transport; (2) the stability criterion that is used to trigger ELM crashes; and (3) the shapes of the plasma profiles and plasma energy lost after each ELM crash. The calibration is presented as well as the sensitivity to the coefficients in the model.

  11. Modeling carbon production and transport during ELMs in DIII-D

    NASA Astrophysics Data System (ADS)

    Hogan, J.; Wade, M.; Coster, D.; Lasnier, C.

    2004-11-01

    Large-scale Type I ELM events could provide a significant C source in ITER, and C production rates depend on incident D flux density and surface temperature, quantities which can vary significantly during an ELM event. Recent progress on DIII-D has improved opportunities for code comparison. Fast time-scale measurements of divertor CIII evolution [1] and fast edge CER measurements of C profile evolution during low-density DIII-D LSN ELMy H-modes (type I) [2] have been modeled using the solps5.0/Eirene99 coupled edge code and time dependent thermal analysis codes. An ELM model based on characteristics of MHD peeling-ballooning modes reproduces the pedestal evolution. Qualitative agreement for the CIII evolution during an ELM event is found using the Roth et al annealing model for chemical sputtering and the sensitivity to other models is described. Significant ELM-to-ELM variations in observed maximum divertor target IR temperature during nominally identical ELMs are investigated with models for C emission from micron-scale dust particles. [1] M Groth, M Fenstermacher et al J Nucl Mater 2003, [2] M Wade, K Burrell et al PSI-16

  12. Non-linear MHD Simulation of ELMs including Pellet Triggered ones for KSTAR tokamak

    NASA Astrophysics Data System (ADS)

    Han, Hyunsun; Park, G.; Strauss, H.; Kim, J. Y.

    2011-10-01

    Three-dimensional non-linear MHD simulations have been conducted to investigate the qualitative characteristics of ELM(Edge Localized Mode)s including pellet induced ones using the M3D code. A linearized velocity perturbation of initial equilibrium is employed to trigger the ELM instability for the simulation of natural ELM, while a density blob, which represents the ionized pellet ablation and is located within the edge pedestal, is adopted in an adiabatic condition for that of pellet induced one. The initial equilibrium is constructed based on a H-mode plasma of KSTAR(Korea Superconducting Tokamak Advanced Research) device. It is found that characteristics of natural ELM simulation are in qualitative agreement with the experimental observations including that density perturbation is much larger than temperature one during ELM instability. Regarding the pellet induced ELM, it is observed that the locally increased pressure due to the fast parallel heat conduction compared to the spread of density perturbation triggers the peeling-ballooning instability resulting in ELM-like relaxation. Detailed results will be presented in the discussion of underlying mechanism and application to KSTAR tokamak.

  13. Optimization of Density and Radiated Power Evolution Control using Magnetic ELM Pace-making in NSTX

    SciTech Connect

    Canik, John; Maingi, Rajesh; Sontag, Aaron C; Bell, R. E.; Gates, D.A.; Gerhardt, S.P.; Kugel, H.; LaBlanc, B. P.; Menard, J.; Paul, S.F.; Sabbagh, S. A.; Soukhanovskii, V. A.

    2010-01-01

    Recent experiments at the National Spherical Torus Experiment (NSTX) have shown that lithium coating of the plasma facing components leads to improved energy confinement, and also the complete suppression of edge-localized modes (ELMs). Due to the lack of ELMs, however, such plasmas suffer from density and radiated power that increase throughout the discharge, often leading to a radiative collapse. Previous experiments have shown that ELMs can be controllably restored into these lithium-conditioned discharges using 3D magnetic perturbations, which reduces impurity accumulation. The use of magnetic ELM pace-making has been optimized to control the evolution of the density and impurity content. Short duration large amplitude 3D field pulses are used, so that the threshold field for destabilization is reached and ELMs triggered quickly, and the field is then removed. A second improvement was made by adding a negative-going pulse to each of the triggering pulses to counteract the vessel eddy currents and reduce time-averaged rotation braking. With these improvements to the triggering waveform, the frequency of the triggered ELMs was increased to over 60 Hz, reducing the average ELM size. The optimum frequency for attaining impurity control while minimizing energy confinement reduction was determined: fairly low frequency ELMs (20 Hz triggering) are sufficient to keep the total radiation fraction below 25% throughout the discharge and avoid radiative collapse, with little reduction in the plasma stored energy. When combined with improved particle fueling, the ELM-pacing technique has been successful in achieving stationary conditions in the line-averaged electron density and total radiated power.

  14. Advances in the physics understanding of ELM suppression using resonant magnetic perturbations in DIII-D

    SciTech Connect

    Wade, M. R.; Nazikian, R.; deGrassie, J. S.; Evans, T. E.; Ferraro, N. M.; Moyer, R. A.; Orlov, D. M.; Buttery, R. J.; Fenstermacher, M. E.; Garofalo, A. M.; Lanctot, M. A.; McKee, G. R.; Osborne, T. H.; Shafer, M. A.; Solomon, W. M.; Snyder, P. B.; Suttrop, W.; Wingen, A.; Unterberg, E. A.; Zeng, L.

    2015-01-14

    Here, recent experiments on DIII-D have increased confidence in the ability to suppress edge-localized modes (ELMs) using edge-resonant magnetic perturbations (RMPs) in ITER, including an improved physics basis for the edge response to RMPs as well as expansion of RMP ELM suppression to more ITER-like conditions. Complete ELM suppression has been achieved utilizing n = 3 RMPs in the ITER baseline scenario. In addition, RMP ELM suppression has been expanded to include plasmas with helium concentrations near 25% and the use of n = 2 RMPs. Analysis of the kinetic profile response suggests that ELM suppression is correlated with the co-alignment of the ω⊥e = 0 location, an n = 3 rational surface, and the top of the pedestal. Modelling predicts that such a co-alignment could potentially lead to island (or island chain) formation just inside the top of the pedestal, inhibiting the growth of the pedestal and thereby maintaining the ELM-free state. Detailed analysis of data obtained during toroidal phase variations of the applied n = 3 RMPs have provided further evidence of an island-like structure at the top of the pedestal. In addition, nearly matched discharges with co-neutral-beam-injection (co-NBI) and counter-NBI have demonstrated the importance of the presence of the ω⊥e = 0 location for ELM suppression. In the counter-NBI cases, the toroidal rotation profile is such that there is no ω⊥e = 0 location and ELMs are not suppressed in conditions in which ELM suppression is generally observed with co-NBI.

  15. Real-time control of ELM and sawtooth frequencies: similarities and differences

    NASA Astrophysics Data System (ADS)

    Lennholm, M.; Frigione, D.; Graves, J. P.; Beaumont, P. S.; Blackman, T.; Carvalho, I. S.; Chapman, I.; Dumont, R.; Felton, R.; Garzotti, L.; Goniche, M.; Goodyear, A.; Grist, D.; Jachmich, S.; Johnson, T.; Lang, P.; Lerche, E.; de la Luna, E.; Monakhov, I.; Mooney, R.; Morris, J.; Nave, M. F. F.; Reich, M.; Rimini, F.; Sips, G.; Sheikh, H.; Sozzi, C.; Tsalas, M.; Contributors, JET

    2016-01-01

    ELMs and Sawteeth, located in different parts of the plasma, are similar from a control engineering point of view. Both manifest themselves through quiescent periods interrupted by periodic collapses. For both, large collapses, following long quiescent periods, have detrimental effects while short periods are associated with decreased confinement. Following the installation of the all metal ‘ITER like wall’ on JET, sawteeth and ELMs also play an important role by expelling tungsten from the core and edge of the plasma respectively. Control of tungsten has therefore been added to divertor heat load reduction, NTM avoidance and helium ash removal as reasons for requiring ELM and sawtooth control. It is therefore of interest to implement control systems to maintain the sawtooth and ELM frequencies in the desired ranges. On JET, ELM frequency control uses radial field ‘kicks’ and pellet and gas injection as actuators, while sawtooth control uses ion cyclotron resonance heating (ICRH). JET experiments have, for the first time, established feedback control of the ELM frequency, via real time variation of the injected gas flow [1]. Using this controller in conjunction with pellet injection allows the ELM frequency to be kept as required despite variations in pellet ELM triggering efficiency. JET Sawtooth control experiments have, for the first time, demonstrated that low field side ICRH, as foreseen for ITER, can shorten sawteeth lengthened by central fast ions [2]. The development of ELM and sawtooth control could be key to achieve stable high performance JET discharges with minimal tungsten content. Integrating such schemes into an overall control strategy will be required in future tokamaks and gaining experience on current tokamaks is essential.

  16. Advances in the physics understanding of ELM suppression using resonant magnetic perturbations in DIII-D

    DOE PAGES

    Wade, M. R.; Nazikian, R.; deGrassie, J. S.; ...

    2015-01-14

    Here, recent experiments on DIII-D have increased confidence in the ability to suppress edge-localized modes (ELMs) using edge-resonant magnetic perturbations (RMPs) in ITER, including an improved physics basis for the edge response to RMPs as well as expansion of RMP ELM suppression to more ITER-like conditions. Complete ELM suppression has been achieved utilizing n = 3 RMPs in the ITER baseline scenario. In addition, RMP ELM suppression has been expanded to include plasmas with helium concentrations near 25% and the use of n = 2 RMPs. Analysis of the kinetic profile response suggests that ELM suppression is correlated with themore » co-alignment of the ω⊥e = 0 location, an n = 3 rational surface, and the top of the pedestal. Modelling predicts that such a co-alignment could potentially lead to island (or island chain) formation just inside the top of the pedestal, inhibiting the growth of the pedestal and thereby maintaining the ELM-free state. Detailed analysis of data obtained during toroidal phase variations of the applied n = 3 RMPs have provided further evidence of an island-like structure at the top of the pedestal. In addition, nearly matched discharges with co-neutral-beam-injection (co-NBI) and counter-NBI have demonstrated the importance of the presence of the ω⊥e = 0 location for ELM suppression. In the counter-NBI cases, the toroidal rotation profile is such that there is no ω⊥e = 0 location and ELMs are not suppressed in conditions in which ELM suppression is generally observed with co-NBI.« less

  17. THE ELM SURVEY. V. MERGING MASSIVE WHITE DWARF BINARIES

    SciTech Connect

    Brown, Warren R.; Kenyon, Scott J.; Kilic, Mukremin; Gianninas, A.; Allende Prieto, Carlos E-mail: skenyon@cfa.harvard.edu E-mail: alexg@nhn.ou.edu

    2013-05-20

    We present the discovery of 17 low-mass white dwarfs (WDs) in short-period (P {<=} 1 day) binaries. Our sample includes four objects with remarkable log g {approx_equal} 5 surface gravities and orbital solutions that require them to be double degenerate binaries. All of the lowest surface gravity WDs have metal lines in their spectra implying long gravitational settling times or ongoing accretion. Notably, six of the WDs in our sample have binary merger times <10 Gyr. Four have {approx}>0.9 M{sub Sun} companions. If the companions are massive WDs, these four binaries will evolve into stable mass transfer AM CVn systems and possibly explode as underluminous supernovae. If the companions are neutron stars, then these may be millisecond pulsar binaries. These discoveries increase the number of detached, double degenerate binaries in the ELM Survey to 54; 31 of these binaries will merge within a Hubble time.

  18. LETTER TO THE EDITOR: Were the chaotic ELMs in TCV the result of an ARMA process?

    NASA Astrophysics Data System (ADS)

    Degeling, A. W.; Lister, J. B.; Martin, Y. R.; Zvejnieks, G.

    2004-10-01

    The results of a previous paper claiming the demonstration that edge localized mode (ELM) dynamics on TCV are chaotic in a number of cases has recently been called into question, because the statistical test employed was found to also identify linear auto regressive—moving average (ARMA) models as chaotic. The TCV ELM data has therefore been re-examined with an improved method that is able to make this distinction, and the ARMA model is found to be an inappropriate description of the dynamics on TCV. The hypothesis that ELM dynamics are chaotic on TCV in a number of cases is therefore still favoured.

  19. ELM behaviour and linear MHD stability of edge ECRH heated ASDEX Upgrade plasmas

    NASA Astrophysics Data System (ADS)

    Burckhart, A.; Dunne, M.; Wolfrum, E.; Fischer, R.; McDermott, R.; Viezzer, E.; Willensdorfer, M.; the ASDEX Upgrade Team

    2016-05-01

    In order to test the peeling-ballooning ELM model, ECRH heating was applied to the edge of ASDEX Upgrade type-I ELMy H-mode plasmas to alter the pedestal pressure and current density profiles. The discharges were analysed with respect to ideal MHD stability. While the ELM frequency increased and the pedestal gradients relaxed with edge ECRH, the MHD stability boundary did not change. The results indicate that the peeling-ballooning model is insufficient to fully explain the triggering of ELM instabilities in the presence of edge ECRH heating.

  20. The Relationship between Type I ELM Severity and Perturbed Electron Transport in NSTX

    NASA Astrophysics Data System (ADS)

    Tritz, Kevin

    2007-11-01

    NSTX provides a unique test bed for probing electron transport due both to its significant role in the steady-state power balance and features of the electron response to transient perturbations. In neutral-beam-heated plasmas in NSTX, most of the heating power is deposited on the electrons. Following large Type I ELMs in some H-mode NSTX discharges, global Te profile declines of 10-30% amplitude are observed. While the soft X-ray data indicates that the ELM itself is causing only a peripheral Te perturbation, the inward propagation of the cold pulse initiated by the ELM is unusually fast (˜ms timescale) and can extend to the core of the plasma. The perturbed electron thermal diffusivity is ˜300 m^2/s for r/a > 0.4, and ˜30 m^2/s for r/a < 0.4. However, in high-triangularity regimes, which exhibit smaller Type I ELM perturbations and an energy loss of a few percent, the perturbation propagation time of several ms implies a perturbed electron thermal diffusivity of 10-20 m^2/s across the plasma radius. Comparison of the ELM energy loss with the electron thermal diffusivity inferred from both ELM and pellet induced `cold pulses', shows a rough proportionality between the ELM magnitude and the perturbed electron thermal diffusivity. Furthermore, comparisons of the linear growth rates of instabilities calculated with the GS2 code show large differences between the large and small Type I ELM regimes. In particular, the ETG mode is the dominant instability following large ELMs, but absent during the small Type I ELM. Interestingly, high-k measurements during ELM events show an increase of short wavelength fluctuations in both the core and edge regions of the plasma, with the increase in amplitude most prominent at wavenumbers of 14-16 cm-1. These results suggest that electron thermal transport plays an important role in determining the total energy loss from Type I ELMs.

  1. Hydrologic data for Little Elm Creek, Trinity River basin, Texas, 1976

    USGS Publications Warehouse

    Slade, R.M.; Hays, T.H.; Schoultz, C.T.

    1976-01-01

    This report contains rainfall, runoff, and storage data collected during the 1976 water year for a 75.5 sq mi area above the stream-gaging station Little Elm Creek near Aubrey, Texas. Floodflows from 35.7 sq mi of the area are regulated by 16 floodwater-retarding structures constructed by the Soil Conservation Service. During the 1976 water year, five storm periods were selected for detailed computations and analyses. Beginning with the 1975 water year, water-quality data is given for Little Elm Creek. Investigations in the Little Elm Creek watershed were terminated on September 30, 1976. (Woodard-USGS)

  2. ELM 2016—data update and new functionality of the eukaryotic linear motif resource

    PubMed Central

    Dinkel, Holger; Van Roey, Kim; Michael, Sushama; Kumar, Manjeet; Uyar, Bora; Altenberg, Brigitte; Milchevskaya, Vladislava; Schneider, Melanie; Kühn, Helen; Behrendt, Annika; Dahl, Sophie Luise; Damerell, Victoria; Diebel, Sandra; Kalman, Sara; Klein, Steffen; Knudsen, Arne C.; Mäder, Christina; Merrill, Sabina; Staudt, Angelina; Thiel, Vera; Welti, Lukas; Davey, Norman E.; Diella, Francesca; Gibson, Toby J.

    2016-01-01

    The Eukaryotic Linear Motif (ELM) resource (http://elm.eu.org) is a manually curated database of short linear motifs (SLiMs). In this update, we present the latest additions to this resource, along with more improvements to the web interface. ELM 2016 contains more than 240 different motif classes with over 2700 experimentally validated instances, manually curated from more than 2400 scientific publications. In addition, more data have been made available as individually searchable pages and are downloadable in various formats. PMID:26615199

  3. ELM Suppression through density profile modification with lithium wall coatings in the National Spherical Torus Experiment

    SciTech Connect

    Maingi, Rajesh; Osborne, T.; LeBlanc, B; Bell, R. E.; Manickam, J.; Snyder, P.; Menard, J.; Mansfield, D.K.; Kugel, H.; Kaita, R.; Gerhardt, S.P.; Sabbagh, S. A.; Kelly, F.A.

    2009-01-01

    Reduction or elimination of edge localized modes (ELMs) while maintaining high confinement is essential for future fusion devices, e.g. the ITER. An ELM-free regime was recently obtained in the National Spherical Torus Experiment, following lithium (li) evaporation onto the plasma facing components. Edge stability calculations indicate that the pre-li discharges were unstable to low-n peeling/ballooning modes, while broader pressure profiles stabilized the post-li discharges. Normalized energy confinement increased by 50% post-li, with no sign of ELMs up to the global stability limit.

  4. A New Dutch Spelling Guide.

    ERIC Educational Resources Information Center

    Kruyt, J. G.; van Sterkenburg, P. G. J.

    This paper describes the development of two new corpus-based Dutch spelling guides using language data gathered by the Institute for Dutch Lexicology, a research institute subsidized by the Dutch and Belgian governments. The guides were produced in 1990 and 1995. The guides are based on two earlier ones, published in 1866 and 1954, but attempt to…

  5. The spindle position checkpoint is coordinated by the Elm1 kinase

    PubMed Central

    Moore, Jeffrey K.; Chudalayandi, Prakash; Heil-Chapdelaine, Richard A.

    2010-01-01

    How dividing cells monitor the effective transmission of genomes during mitosis is poorly understood. Budding yeast use a signaling pathway known as the spindle position checkpoint (SPC) to ensure the arrival of one end of the mitotic spindle in the nascent daughter cell. An important question is how SPC activity is coordinated with mother–daughter polarity. We sought to identify factors at the bud neck, the junction between mother and bud, which contribute to checkpoint signaling. In this paper, we show that the protein kinase Elm1 is an obligate regulator of the SPC, and this function requires localization of Elm1 to the bud neck. Furthermore, we show that Elm1 promotes the activity of the checkpoint kinase Kin4. These findings reveal a novel function for Elm1 in the SPC and suggest how checkpoint activity may be linked to cellular organization. PMID:21041444

  6. Numerical analysis of key factors for the appearance of grassy ELMs in tokamak plasmas

    NASA Astrophysics Data System (ADS)

    Aiba, N.; Oyama, N.

    2012-11-01

    Numerical stability analysis of edge-localized MHD mode is performed to identify the origin of small-amplitude ‘grassy ELMs’ on the basis of current understanding of kinetic effects on ballooning mode stability. These qualitative and quantitative analyses show that short wavelength ballooning mode can play an important role in a grassy ELM stability even when kinetic effects are taken into account. After showing the importance of kinetic effects for discussing grassy ELM physics, impacts of plasma parameters important for realizing a grassy ELM plasma experimentally are investigated numerically from the viewpoint of the edge-localized MHD stability including these kinetic effects. These analyses show that low plasma ellipticity is preferable to realize a grassy ELM plasma due to destabilizing ballooning mode by preventing access to the second stability region of the ballooning mode.

  7. Study on Sawtooth and ELM activities in DIII-D and KSTAR Plasmas

    NASA Astrophysics Data System (ADS)

    Bak, J.-G.; Kim, H. S.; Lee, S. G.; Lee, K. D.; Ko, W. H.; Kim, J.; Jeon, Y. M.; Kim, W. C.; Bae, Y. S.; Strait, E. J.; La Haye, R. J.; Buttery, R. J.; Wade, M. R.; Park, J. K.; Hanson, J. M.

    2012-10-01

    Sawtooth precursor oscillations (SPOs) are studied in neutral beam heated plasmas on DIII-D and KSTAR. The characteristics of the SPO (5-20 kHz, m/n=1/1) are investigated using magnetic sensors along with electron cyclotron emission (ECE) and soft x-ray diagnostics. In addition, the Type I edge localized mode (ELM) precursors (8-40 kHz, n=2,3) are detected before the ELM burst in neutral beam heated plasmas. The characteristics of the ELM precursors are investigated by using magnetic sensor data. In this work, the experimental investigations of the SPOs and ELM precursors in DIII-D and KSTAR plasmas will be presented.

  8. ECE imaging of modified edge localized modes (ELMs) under n=1 magnetic perturbations in KSTAR

    NASA Astrophysics Data System (ADS)

    Lee, Jaehyun; Yun, G. S.; Kim, M.; Choi, M. J.; Lee, W.; Park, H. K.; Lee, J. H.; Jeon, Y. M.; Domier, C. W.; Luhmann, N. C., Jr.; Donné, A. J. H.

    2012-10-01

    In order to control the ELMs in KSTAR H-mode plasmas, magnetic perturbations (MPs) of toroidal mode number n=1 were introduced through three sets of field error correction (FEC) coils [1] during the 2011 campaign. The plasma response was studied in 2-D using electron cyclotron emission imaging (ECEI) diagnostic [2], which showed alteration of both the spatial structure and temporal dynamics of the ELMs. The characteristics of the ELMs such as the growth rate, filament size, and poloidal flow are compared before and after the n=1 MP for various configurations of the FEC coil currents. In particular, the ELM suppression by resonant MP condition is characterized by occasional (non-periodic) tiny transport events, which involve the appearance and crash of transient filament structure localized near the separatrix.[4pt] [1] Y. Jeon et al., accepted for publication in Phys. Rev. Lett.[0pt] [2] G.S. Yun et al., Phys. Rev. Lett., 107, 045004 (2011).

  9. Suitability of thirteen different host species for elm leaf beetle, Xanthogaleruca luteola (Coleoptera: Chrysomelidae)

    Treesearch

    Richard W. Hall; Alden M. Townsend; Jack H. Barger

    1987-01-01

    Thirteen different host species for elm leaf beetle, Xanthogaleruca luteola (Muller), were assayed to determine their relative suitability. Species examined were Ulmus parvifolia Jacq., U. thomasii Sarg., U. laevis Pall., U. wilsoniana Schneid., U....

  10. Recent progress in the quantitative validation of JOREK simulations of ELMs in JET

    NASA Astrophysics Data System (ADS)

    Pamela, S. J. P.; Huijsmans, G. T. A.; Eich, T.; Saarelma, S.; Lupelli, I.; Maggi, C. F.; Giroud, C.; Chapman, I. T.; Smith, S. F.; Frassinetti, L.; Becoulet, M.; Hoelzl, M.; Orain, F.; Futatani, S.; Contributors, JET

    2017-07-01

    Future devices like JT-60SA, ITER and DEMO require quantitative predictions of pedestal density and temperature levels, as well as inter-ELM and ELM divertor heat fluxes, in order to improve global confinement capabilities while preventing divertor erosion/melting in the planning of future experiments. Such predictions can be obtained from dedicated pedestal models like EPED, and from non-linear MHD codes like JOREK, for which systematic validation against current experiments is necessary. In this paper, we show progress in the quantitative validation of the JOREK code using JET simulations. Results analyse the impact of diamagnetic terms on the dynamics and size of the ELMs, and evidence is provided that the onset of type-I ELMs is not governed by linear MHD stability alone, but that a nonlinear threshold could be responsible for large MHD events at the plasma edge.

  11. ELM suppression by resonant magnetic perturbation in high-performance, stationary plasmas

    SciTech Connect

    Hudson, B.; Evans, T. E.; Osborne, T. H.; Petty, C C.; Snyder, P. B.; Unterberg, Ezekial A

    2010-01-01

    The method of resonant magnetic perturbation (RMP) has been shown to suppress edge-localized modes (ELMs) in the high-performance, stationary (or 'hybrid') scenario in the DIII-D tokamak. Calculations of stability to peeling-ballooning (P-B) modes are shown to be consistent with the observed suppression of type-I ELMs, while the ELM suppression, dependence on edge safety factor and density pump-out are similar for hybrids and standard H-mode discharges. However, other small ELMs can appear when the edge safety factor is outside the resonance window or when the H-mode pedestal is perturbed, which are not related to P-B stability. The role of the edge bootstrap current in determining stochastic heat transport during RMP is discussed.

  12. Hydrologic data for Little Elm Creek, Trinity River basin, Texas, 1975

    USGS Publications Warehouse

    Slade, R.M.; Taylor, J.M.

    1977-01-01

    This report contains rainfall, runoff, and storage data collected during the 1975 water year for a 75.5 sq mi area above the stream-gaging station Little Elm Creek near Aubrey, Texas. Floodflows from 35.7 sq mi of the area are regulated by 16 floodwater-retarding structures constructed by the Soil Conservation Service. Six storm periods were selected for detailed computations and analyses. Water-quality data is given for Little Elm Creek. (Woodard-USGS)

  13. ELM-related fluctuations in PBX-M H-modes

    SciTech Connect

    Kaye, S.M.; Hahm, T.S.; Sesnic, S.; Tang, W.; Roney, P.; Davis, W.; Dunlap, J.L.; Harris, J.H.

    1994-04-01

    Edge Localized Modes, or ELMs, are at the same time both disadvantageous and advantageous features of H-modes. ELMs can cause energy and particle losses from the plasma, with instantaneous energy losses reaching 40% of the total stored energy in the case of large-amplitude ELMs. The energy loss from these ELMs, or closely spaced smaller ELMs, may result in what is known as a beta-collapse, an event in which energy is lost over a substantial duration of the discharge. On the other hand, if controlled, the ELM related energy and, especially, impurity losses can lead to near steady-state discharge conditions with relatively low radiative power losses. The importance of ELMs in the development of the H-phase has led to numerous studies which attempt to uncover their nature. The purpose of the present work is to present additional observations of, most notably, high frequency magnetic fluctuations associated with ELMS. There are some observations here that are consistent with previously reported ones, namely the appearance of high frequency ({ge}250 kHz) activity prior to the D{sub {alpha}} increase, suggesting again that the rise in D{sub {alpha}} is some delayed response to an instability occurring farther inside the plasma edge. While this high frequency activity is global, with high coherence for all coil pairs both on the inside and outside midplane, there is no identifiable mode structure. Reported here for the first time are observations of a very intense outward ballooning feature that appears simultaneously with the D{sub {alpha}} increase and lasts for about 5 msec. The toroidal mode structure of this feature is clearly identifiable, consisting of a series of toroidal harmonics from n=3 to 8, at frequencies given by f{sub n}=f{sub 0}+n{Delta}f, with f{sub 0}=30 to 50 kHz and A{Delta}=20 to 30 kHz.

  14. Suppression of type-I ELMs with reduced RMP coil set on DIII-D

    DOE PAGES

    Orlov, Dmitriy M.; Moyer, Richard A.; Evans, Todd E.; ...

    2016-02-19

    Recent experiments on DIII-D have demonstrated that having a toroidally-monochromatic spectral content of edge-resonant magnetic perturbations (RMPs) is not a necessary condition for suppression of Edge Localized Modes (ELMs). Robust ELM suppression has been reproducibly obtained on DIII-D during experiments in which various non-axisymmetric coil loops were turned off pseudo-randomly producing a variety of n=1, n=2, and n=3 spectral contributions. It was shown that RMP ELM suppression could be achieved with as few as 5 out of 12 internal coil loops (I-coils) on DIII-D at similar coil currents and with good plasma confinement. Linear MHD plasma response (M3DC1, IPEC, MARS)more » and vacuum (SURFMN, TRIP3D) modeling have been performed in order to understand the effects of the perturbation spectrum on the plasma response and ELM suppression. The results suggest that reduction of the dominant n=3 perturbation field is compensated by increased n=2 field in the plasma that may lead to RMP ELM suppression at lower levels of n=3 perturbative magnetic flux from the I-coils. These results provide additional confidence that ITER may be capable of RMP ELM suppression in the event of multiple internal coil failures.« less

  15. ELM triggering by energetic particle driven mode in wall-stabilized high-β plasmas

    NASA Astrophysics Data System (ADS)

    Matsunaga, G.; Aiba, N.; Shinohara, K.; Asakura, N.; Isayama, A.; Oyama, N.; the JT-60 Team

    2013-07-01

    In the JT-60U high-β plasmas above the no-wall β limit, a triggering of an edge localized mode (ELM) by an energetic particle (EP)-driven mode has been observed. This EP-driven mode is thought to be driven by trapped EPs and it has been named EP-driven wall mode (EWM) on JT-60U (Matsunaga et al 2009 Phys. Rev. Lett. 103 045001). When the EWM appears in an ELMy H-mode phase, ELM crashes are reproducibly synchronized with the EWM bursts. The EWM-triggered ELM has a higher repetition frequency and less energy loss than those of the natural ELM. In order to trigger an ELM by the EP-driven mode, some conditions are thought to be needed, thus an EWM with large amplitude and growth rate, and marginal edge stability. In the scrape-off layer region, several measurements indicate an ion loss induced by the EWM. The ion transport is considered as the EP transport through the edge region. From these observations, the EP contributions to edge stability are discussed as one of the ELM triggering mechanisms.

  16. Identification and control of nonlinear system based on Laguerre-ELM Wiener model

    NASA Astrophysics Data System (ADS)

    Tang, Yinggan; Han, Zhenzhen; Liu, Fucai; Guan, Xinping

    2016-09-01

    In this paper, a new Wiener model is presented for identification and control of single-input single-output (SISO) nonlinear systems. The proposed Wiener model consists of a linear Laguerre filter in cascaded with an extreme learning machine (ELM) neural network (called Laguerre-ELM Wiener model). Laguerre filter can approximate a stable linear system to any degree of accuracy with a small number of Laguerre filters, which provides a parsimony structure and high level accuracy simultaneously. To determine the appropriated number of Laguerre filters in Laguerre-ELM Wiener model, Lipschitz quotient criterion is adapted to determine the order of linear part. A generalized ELM algorithm is proposed to estimate the parameters of Laguerre-ELM Wiener model. Once the unknown nonlinear system is identified using Laguerre-ELM Wiener model, a generalized predictive control (GPC) algorithm is designed for control of nonlinear system. The advantage of the proposed control method is that it transfers a nonlinear control problem to a linear one by inserting the inverse of static nonlinear section. Simulation results demonstrate the effectiveness of the proposed identification and control algorithms.

  17. Study of the spectral properties of ELM precursors by means of wavelets

    NASA Astrophysics Data System (ADS)

    Poli, F. M.; Sharapov, S. E.; Chapman, S. C.; Contributors, JET-EFDA

    2008-09-01

    The high confinement regime (H-mode) in tokamaks is accompanied by the occurrence of bursts of MHD activity at the plasma edge, so-called edge localized modes (ELMs), lasting less than 1 ms. These modes are often preceded by coherent oscillations in the magnetic field, the ELM precursors, whose mode numbers along the toroidal and the poloidal directions can be measured from the phase shift between Mirnov pickup coils. When the ELM precursors have a lifetime shorter than a few milliseconds, their toroidal mode number and their nonlinear evolution before the ELM crash cannot be studied reliably with standard techniques based on Fourier analysis, since averaging in time is implicit in the computation of the Fourier coefficients. This work demonstrates significant advantages in studying spectral features of the short-lived ELM precursors by using Morlet wavelets. It is shown that the wavelet analysis is suitable for the identification of the toroidal mode numbers of ELM precursors with the shortest lifetime, as well as for studying their nonlinear evolution with a time resolution comparable to the acquisition rate of the Mirnov coils.

  18. Suppression of type-I ELMs with reduced RMP coil set on DIII-D

    SciTech Connect

    Orlov, Dmitriy M.; Moyer, Richard A.; Evans, Todd E.; Paz-Soldan, Carlos; Ferraro, Nathaniel M.; Nazikian, Raffi; deGrassie, John S.; Grierson, Brian A.; Eldon, David; Fenstermacher, Max E.; King, J. D.; Logan, N. C.; Lanctot, M. J.; Maingi, R.; Snyder, P. B.; Strait, E. J.; Wingen, A.

    2016-02-19

    Recent experiments on DIII-D have demonstrated that having a toroidally-monochromatic spectral content of edge-resonant magnetic perturbations (RMPs) is not a necessary condition for suppression of Edge Localized Modes (ELMs). Robust ELM suppression has been reproducibly obtained on DIII-D during experiments in which various non-axisymmetric coil loops were turned off pseudo-randomly producing a variety of n=1, n=2, and n=3 spectral contributions. It was shown that RMP ELM suppression could be achieved with as few as 5 out of 12 internal coil loops (I-coils) on DIII-D at similar coil currents and with good plasma confinement. Linear MHD plasma response (M3DC1, IPEC, MARS) and vacuum (SURFMN, TRIP3D) modeling have been performed in order to understand the effects of the perturbation spectrum on the plasma response and ELM suppression. The results suggest that reduction of the dominant n=3 perturbation field is compensated by increased n=2 field in the plasma that may lead to RMP ELM suppression at lower levels of n=3 perturbative magnetic flux from the I-coils. These results provide additional confidence that ITER may be capable of RMP ELM suppression in the event of multiple internal coil failures.

  19. Divertor load footprint of ELMs in pellet triggering and pacing experiments at JET

    NASA Astrophysics Data System (ADS)

    Frigione, D.; Garzotti, L.; Lennholm, M.; Alper, B.; Artaserse, G.; Bennett, P.; Giovannozzi, E.; Eich, T.; Kocsis, G.; Lang, P. T.; Maddaluno, G.; Mooney, R.; Rack, M.; Sips, G.; Tvalashvili, G.; Viola, B.; Wilkes, D.

    2015-08-01

    An investigation of pellet pacing and triggering of Edge Localized Modes (ELMs) was carried out in the frame of ELM mitigation studies aimed at reducing their damaging effects on the plasma-facing components (PFCs). The divertor power load footprint of triggered ELMs was compared with gas puffing controlled ELMs. Small pellets, corresponding to a few per cent of the target plasma particle inventory, were used to minimize the fueling effect and the total particle throughput. There is no evidence that pellets can reduce the divertor power load with respect to gas fueling when operating at the same ELM frequency. The line average density and the energy confinement time remained constant when the gas was progressively substituted by pellets. The launch from the Vertical High Field Side (VHFS) confirmed to be more efficient in ELM triggering than from the Low Field Side (LFS) while the power load footprint remained the same both in time evolution and in spatial distribution when changing the injection geometry.

  20. Antenna loading impedance changes during arcs and ELMs on DIII-D

    SciTech Connect

    Baity, F.W.; DeGrassie, J.; Goulding, R.H.; Hoffman, D.J.; Phelps, D.R.; Pinsker, R.I.

    1997-04-01

    RF heating of ELMing H-mode plasmas poses the problem of discriminating between arcs and ELMs. Excessive reflected power or VSWR is typically used as the indication that an arc has occurred. ELMs also can result in large reflected power levels; however, it is not presumed desirable to shut off the RF power during ELMs. DIII-D and other tokamaks have investigated several different techniques to deal with this issue. A complicating factor is the variety of antenna matching circuits in use or proposed. In some instances, such as DIII-D, reflections due to ELMs are shunted to the dummy load only, whereas arcs reflect power also to the transmitter. The ideal system would have a response time on the order of 10 {mu}s and would neither miss arcs nor produce false alarms. Measurements of loading caused by arcs and ELMs have been made to determine whether a technique based on the differences in the reactive component is feasible. {copyright} {ital 1997 American Institute of Physics.}

  1. Divertor heat loads in RMP ELM controlled H-mode plasmas on DIII-D*

    SciTech Connect

    Jakubowski, M; Lasnier, C; Schmitz, O; Evans, T; Fenstermacher, M; Groth, M; Watkins, J; Eich, T; Moyer, R; Wolf, R; Baylor, L; Boedo, J; Burrell, K; Frerichs, H; deGrassie, J; Gohil, P; Joseph, I; Lehnen, M; Leonard, A; Petty, C; Pinsker, R; Reiter, D; Rhodes, T; Samm, U; Snyder, P; Stoschus, H; Osborne, T; Unterberg, B; West, W

    2008-10-13

    In this paper the manipulation of power deposition on divertor targets at DIII-D by application of resonant magnetic perturbations (RMPs) is analyzed. It has been found that heat transport shows a different reaction to the applied RMP depending on the plasma pedestal collisionality. At pedestal electron collisionality above 0.5 the heat flux during the ELM suppressed phase is of the same order as the inter-ELM in the non-RMP phase. Below this collisionality value we observe a slight increase of the total power flux to the divertor. This can be caused by much more negative potential at the divertor surface due to hot electrons reaching the divertor surface from the pedestal area and/or so called pump out effect. In the second part we discuss modification of ELM behavior due to the RMP. It is shown, that the width of the deposition pattern in ELMy H-mode depends linearly on the ELM deposited energy, whereas in the RMP phase of the discharge those patterns seem to be controlled by the externally induced magnetic perturbation. D{sub 2} pellets injected into the plasma bulk during ELM-free RMP H-mode lead in some cases to a short term small transients, which have very similar properties to ELMs in the initial RMP-on phase.

  2. Numerical investigation of plasma-wall interaction during burst of ELMs in a tokamak device

    NASA Astrophysics Data System (ADS)

    Ou, Jing; Lin, Binbin; Zhao, Xiaoyun

    2017-01-01

    In the tokamak high confinement mode (H-mode), the transient heat fluxes caused by edge localized modes (ELMs) will eventually irradiate the plasma-facing components and may erode, even melt them. To study the performance of the plasma-wall interaction during ELMs, interactions among heat flux from plasma, surface temperature, and electron emission are simulated by considering self-consistency among plasma transport in the sheath, deposited heat at the wall, and material thermal response for carbon (C) and tungsten (W) walls. It is found that the sheath structure determines the surface temperature, which may in turn influence on the sheath. A large amount of electron emission can change the heat load from the plasma to the material surface due to the variation of the ELMs-induced electron temperature and the surface temperature. During the burst of ELMs, the surface temperature rises rapidly at first and then reaches a saturation state with a certain range of fluctuation. The development of these processes depends strongly on the characteristic of ELMs, deposited heat at the wall, and material properties. Simulation results also show that the erosion of the Experimental Advanced Superconducting Tokamak (EAST) divertor target is of no concern in H-mode operation with ELMs for the current and possible future operation parameters.

  3. Effect of Island Overlap on ELM Suppression by Resonant Magnetic Perturbations in DIII-D

    SciTech Connect

    Fenstermacher, M E; Evans, T E; Osborne, T H; Schaffer, M J; Aldan, M P; deGrassie, J S; Gohil, P; Joseph, I; Moyer, R A; Snyder, P B; Groebner, R J; Jakubowski, M; Leonard, A W; Schmitz, O

    2007-11-08

    Recent DIII-D [J.L. Luxon, et al., Nucl. Fusion 43, 1813 (2003)] experiments show a correlation between the extent of overlap of magnetic islands induced in the edge plasma by perturbation coils and complete suppression of Type-I edge localized modes (ELMs) in plasmas with ITER-like electron pedestal collisionality {nu}*{sub e} {approx} 0.1, flux surface shape and low edge safety factor (q{sub 95} {approx} 3.6). With fixed n = 3 resonant magnetic perturbation (RMP) strength, ELM suppression is obtained only in a finite window in the edge safety factor (q{sub 95}) consistent with maximizing the resonant component of the applied helical field. ELM suppression is obtained over an increasing range of q{sub 95} by either increasing the n = 3 RMP strength, or by adding n = 1 perturbations to 'fill in' gaps between islands across the edge plasma. The suppression of Type-I ELMs correlates with a minimum width of the edge region having magnetic islands with Chirikov parameter >1.0, based on vacuum calculations of RMP mode components excluding the plasma response or rotational shielding. The fraction of vacuum magnetic field lines that are lost from the plasma, with connection length to the divertor targets comparable to an electron-ion collisional mean free path, increases throughout the island overlap region in the ELM suppressed case compared with the ELMing case.

  4. Evolution of the 2D Spatial Profile of Visible Emission During an ELM in the DIII-D Divertor

    NASA Astrophysics Data System (ADS)

    Fenstermacher, M. E.; Groth, M.; Lasnier, C. J.; Boedo, J. C.; Leonard, A. W.

    2001-10-01

    The transient particle and energy loads due to Edge Localized Modes (ELMs) are a significant problem for the design of divertors in future tokamak reactors. Detailed understanding of the effect of the ELM perturbation on the 2D distribution of radiation in the divertor is needed to validate computer simulations and investigate mitigation schemes. Gated, intensified, tangentially viewing cameras with wavelength filters were used in combination with tomographic reconstruction techniques to provide 2D profiles of carbon and deuterium emission during ELM evolution in the DIII-D divertor. Preliminary 2D reconstructions of D_α and CIII visible emission during large Type-I ELMs will be shown. The dramatic broadening of the D_α emission profile near the target will be compared with the broadening of the heat flux profiles during ELMs from IRTV. Plans for obtaining the detailed temporal evolution of the 2D spatial profile of the divertor emission throughout an ELM will be described.

  5. Experimental Demonstration of High Frequency ELM Pacing by Pellet Injection on DIII-D and Extrapolation to ITER

    SciTech Connect

    Baylor, Larry R; Commaux, Nicolas JC; Jernigan, Thomas C; Meitner, Steven J; Brooks, N. H.; Combs, Stephen Kirk; Evans, T.E.; Fenstermacher, M. E.; Lasnier, C. J.; Moyer, R.A.; Osborne, T. H.; Parks, P. B.; Strait, E. J.; Unterberg, Ezekial A; Loarte, A.

    2012-01-01

    . The injection of high repetition rate deuterium pellets is shown to trigger high-frequency edge localized modes (ELMs) in otherwise low natural ELM frequency H-mode deuterium discharges in the DIII-D tokamak. The resulting triggered ELMs have significantly lower energy and particle fluxes to the divertor than the natural ELMs. The plasma global energy confinement and density are not strongly affected by the pellet perturbations. The plasma core impurity density is strongly reduced with the application of the pellets. These experiments were performed in plasmas designed to match the ITER baseline configuration in shape and normalized operation with input power just above the H-mode power threshold. This strongly reduced ELM intensity shows promise for exploitation in ITER to control ELM size while maintaining high plasma purity and performance.

  6. Turbulence Dynamics During RMP-ELM Suppressed Discharges

    NASA Astrophysics Data System (ADS)

    McKee, G. R.; Yan, Z.; Schmitz, O.; Buttery, R. J.; Evans, T. E.; Wade, M. R.; Schmitz, L.; Moyer, R. A.

    2011-10-01

    Long-wavelength density fluctuations in the plasma edge region (0 . 75 < r / a < 1 . 0) change markedly in response to applied resonant magnetic field perturbations, used to suppress ELMs. The RMP-enhanced fluctuations, measured with a 2D array of BES channels, have a radial correlation length of a few cm and span 50-400 kHz in frequency. Modulated RMPs are used to examine the fast temporal dynamics of the turbulence and related parameters. Inside of the pedestal (0 . 8 < r / a < 0 . 9), turbulence is found to change rapidly with the applied RMP, with a few ms response time, suggesting that enhanced turbulence may play a causative role in the observed increased particle and momentum transport. Fluctuations in the pedestal region exhibit a more complex response, initially decreasing with reduced RMP, but subsequently increasing as the pedestal pressure gradient increases. New measurements from upcoming experiments on the q95 dependence of the turbulence and flow response to RMPs will also be presented. Work supported in part by US DOE under DE-FG02-08ER54999, DE-FG02-89ER53296, DE-FC02-04ER54698, DE-FG02-08ER54984, and DE-FG02-07ER54917.

  7. Effects of ELMs on ITER divertor armour materials

    NASA Astrophysics Data System (ADS)

    Zhitlukhin, A.; Klimov, N.; Landman, I.; Linke, J.; Loarte, A.; Merola, M.; Podkovyrov, V.; Federici, G.; Bazylev, B.; Pestchanyi, S.; Safronov, V.; Hirai, T.; Maynashev, V.; Levashov, V.; Muzichenko, A.

    2007-06-01

    This paper is concerned with investigation of an erosion of the ITER-like divertor plasma facing components under plasma heat loads expected during the Type I ELMs in ITER. These experiments were carried out on plasma accelerator QSPA at the SRC RF TRINITI under EU/RF collaboration. Targets were exposed by series repeated plasma pulses with heat loads in a range of 0.5-1.5 MJ/m2 and pulse duration 0.5 ms. Erosion of CFC macrobrushes was determined mainly by sublimation of PAN-fibres that was less than 2.5 μm per pulse. The CFC erosion was negligible at the energy density less than 0.5 MJ/m2 and was increased to the average value 0.3 μm per pulse at 1.5 MJ/m2. The pure tungsten macrobrushes erosion was small in the energy range of 0.5-1.3 MJ/m2. The sharp growth of tungsten erosion and the intense droplet ejection were observed at the energy density of 1.5 MJ/m2.

  8. A Mechanism of ELM Mitigation by External Magnetic Field Perturbations

    NASA Astrophysics Data System (ADS)

    Singh, Raghvendra; Jhang, H.; Kim, J.-H.; Hahm, T. S.

    2016-10-01

    We study the impact of external magnetic perturbations (EMP) on the stability of ballooning mode (BM). We use: 1) the two-step process; 2) standard four wave interactions. In two-step process, we consider EMP are long wave-length perturbations interacting with short scale BM and generating side-bands of higher harmonics. This calculates contributions from all the high toroidal mode numbers. EMP can modify the dispersion characteristics of BM - the growth spectrum becomes broader in kBM space. The increase in high kBM can lead to the mitigation of an ELM crash by increasing turbulent transport. New nonlinear instability is also found even below the BM threshold at large EMP amplitude. In four wave interaction, EMP act like a short scale pump wave interacting with BM and creating two sidebands. The side-bands couple with the pump and produce the ponderomotive force, magnetic stress at BM frequency. EMP may enhance the BM instability threshold if RMP K->BM <=K->RMP and reduce the threshold if K->BM >K->RMP .

  9. H-Mode Turbulence, Power Threshold, ELM, and Pedestal Studies in NSTX

    SciTech Connect

    R. Maingi; C.E. Bush; E.D. Fredrickson; D.A. Gates; S.M. Kaye; B.P. LeBlanc; J.E. Menard; H. Meyer; D. Mueller; N. Nishino; A.L. Roquemore; S.A. Sabbagh; K. Tritz; S.J. Zweben; M.G. Bell; R.E. Bell; T. Biewer; J.A. Boedo; D.W. Johnson; R. Kaita; H.W. Kugel; R.J. Maqueda; T. Munsat; R. Raman; V.A. Soukhanovskii; T. Stevenson; D. Stutman

    2004-10-28

    High-confinement mode (H-mode) operation plays a crucial role in NSTX [National Spherical Torus Experiment] research, allowing higher beta limits due to reduced plasma pressure peaking, and long-pulse operation due to high bootstrap current fraction. Here, new results are presented in the areas of edge localized modes (ELMs), H-mode pedestal physics, L-H turbulence, and power threshold studies. ELMs of several other types (as observed in conventional aspect ratio tokamaks) are often observed: (1) large, Type I ELMs, (2) ''medium'' Type II/III ELMs, and (3) giant ELMs which can reduce stored energy by up to 30% in certain conditions. In addition, many high-performance discharges in NSTX have tiny ELMs (newly termed Type V), which have some differences as compared with ELM types in the published literature. The H-mode pedestal typically contains between 25-33% of the total stored energy, and the NSTX pedestal energy agrees reasonably well with a recent international multi-machine scaling. We find that the L-H transition occurs on a {approx}100 {micro}sec timescale as viewed by a gas puff imaging diagnostic, and that intermittent quiescent periods precede the final transition. A power threshold identity experiment between NSTX and MAST shows comparable loss power at the L-H transition in balanced double-null discharges. Both machines require more power for the L-H transition as the balance is shifted toward lower single null. High field side gas fueling enables more reliable H-mode access, but does not always lead to a lower power threshold e.g., with a reduction of the duration of early heating. Finally the edge plasma parameters just before the L-H transition were compared with theories of the transition. It was found that while some theories can separate well-developed L- and H-mode data, they have little predictive value.

  10. Pruning The ELM Survey: Characterizing Candidate Low-mass White Dwarfs through Photometric Variability

    NASA Astrophysics Data System (ADS)

    Bell, Keaton J.; Gianninas, A.; Hermes, J. J.; Winget, D. E.; Kilic, Mukremin; Montgomery, M. H.; Castanheira, B. G.; Vanderbosch, Z.; Winget, K. I.; Brown, Warren R.

    2017-02-01

    We assess the photometric variability of nine stars with spectroscopic Teff and log g values from the ELM Survey that locates them near the empirical extremely low-mass (ELM) white dwarf instability strip. We discover three new pulsating stars: SDSS J135512.34+195645.4, SDSS J173521.69+213440.6, and SDSS J213907.42+222708.9. However, these are among the few ELM Survey objects that do not show radial velocity (RV) variations that confirm the binary nature expected of helium-core white dwarfs. The dominant 4.31 hr pulsation in SDSS J135512.34+195645.4 far exceeds the theoretical cut-off for surface reflection in a white dwarf, and this target is likely a high-amplitude δ Scuti pulsator with an overestimated surface gravity. We estimate the probability to be less than 0.0008 that the lack of measured RV variations in four of eight other pulsating candidate ELM white dwarfs could be due to low orbital inclination. Two other targets exhibit variability as photometric binaries. Partial coverage of the 19.342 hr orbit of WD J030818.19+514011.5 reveals deep eclipses that imply a primary radius >0.4 R⊙—too large to be consistent with an ELM white dwarf. The only object for which our time series photometry adds support to ELM white dwarf classification is SDSS J105435.78‑212155.9, which has consistent signatures of Doppler beaming and ellipsoidal variations. We conclude that the ELM Survey contains multiple false positives from another stellar population at Teff ≲ 9000 K, possibly related to the sdA stars recently reported from SDSS spectra.

  11. Dutch perfusion incident survey.

    PubMed

    Groenenberg, Ingrid; Weerwind, Patrick W; Everts, Peter A M; Maessen, Jos G

    2010-09-01

    Cardiopulmonary bypass procedures remain complex, involving many potential risks. Therefore, a nationwide retrospective study was conducted to gain insight into the number of incidents and accidents in Dutch adult perfusion practice. An anonymous postal survey (85 questions about hardware, disposables, fluids and medication, air emboli, anticoagulation, practice, and safety measures) was sent to all Dutch perfusionists involved in adult cardiovascular perfusion during 2006 and 2007. To guarantee complete anonymity, respondents were asked to return the survey to a notary who discarded personal information. The net response rate was 72% and covered 23,500 perfusions. Individual respondents performed 240 ± 103 perfusions during the 2-year study period and had 13.8 ± 8.7 years of practical experience. The incident rate was 1 per 15.6 perfusions and the adverse event rate was 1 per 1,236 perfusions. The three most reported incidents were: (1) persistent inability to raise the activated coagulation time above 400s during perfusion (184 incidents); (2) an allergic or anaphylactic reaction to drugs, fluids, or blood products (114 incidents); and (3) clotting formation in the extracorporeal circuit (74 incidents). Furthermore, pre-bypass safety measures showed no statistically significant association with the reported incidents. In comparison with data from the recent literature, the reported number of incidents is high. Nevertheless, the adverse outcome rate is well matched to other published surveys. The relatively high response rate conveys the impression that the Dutch perfusionist is vigilant and willing to report incidents. Hence, a web-based Dutch perfusion incident registration system is recommended.

  12. Dutch euthanasia revisited.

    PubMed

    Fenigsen, R

    1997-01-01

    The results of a follow-up study of euthanasia by the Dutch government, five years after the first study, were published on November 26, 1996. This article provides a detailed review of the two reports comparing and contrasting the statistics cited therein. The author notes that the "rules of careful conduct" proposed by the courts and by the Royal Dutch Society of Medicine were frequently disregarded. Special topics included for the first time in the second study were the notification and non-prosecution procedure, euthanasia of newborns and infants, and assisted suicide in psychiatric practice. The authors of the follow-up report state that it would be desirable to reduce the number of "terminations of life without patients' request," but this must be the common responsibility of the doctor and the patient. They suggest that the person who does not wish to have his life terminated should declare this clearly, in advance, verbally and in writing, preferably in the form of a living will. Involuntary euthanasia was rampant in 1990 and equally rampant in 1995. The author concludes that Dutch doctors who practice euthanasia are not on the slippery slope. From the very beginning, they have been at the bottom.

  13. Broadening of divertor heat flux profile with increasing number of ELM filaments in NSTX

    DOE PAGES

    Ahn, J. -W.; Maingi, R.; Canik, J. M.; ...

    2014-11-13

    Edge localized modes (ELMs) represent a challenge to future fusion devices, owing to cyclical high peak heat fluxes on divertor plasma facing surfaces. One ameliorating factor has been that the heat flux characteristic profile width has been observed to broaden with the size of the ELM, as compared with the inter-ELM heat flux profile. In contrast, the heat flux profile has been observed to narrow during ELMs under certain conditions in NSTX. Here we show that the ELM heat flux profile width increases with the number of filamentary striations observed, i.e., profile narrowing is observed with zero or very fewmore » striations. Because NSTX often lies on the long wavelength current-driven mode side of ideal MHD instabilities, few filamentary structures can be expected under many conditions. Lastly, ITER is also projected to lie on the current driven low-n stability boundary, and therefore detailed projections of the unstable modes expected in ITER and the heat flux driven in ensuing filamentary structures is needed.« less

  14. A stationary long-pulse ELM-absent H-mode regime in EAST

    NASA Astrophysics Data System (ADS)

    Ye, Y.; Xu, G. S.; Wan, B. N.; Chen, R.; Yan, N.; Guo, H. Y.; Shao, L. M.; Yang, Q. Q.; Wang, H. Q.; Zhang, W.; Xia, T. Y.; Zhang, T.; Li, Y. Y.; Wang, T. F.; Zang, Q.; Hu, Y. J.; Wu, G. J.; Zhang, L.; Hao, B. L.; Wang, L.; Li, Y. L.; Wu, X. Q.; Chen, L.; Lan, H.; Wang, Y. F.; Xu, J. C.; Hu, G. H.; Ding, S. Y.; Zhang, H.; Zhao, N.; Li, J.; The EAST Team

    2017-08-01

    A stationary edge-localized mode (ELM)-absent H-mode regime, with an electrostatic edge coherent mode (ECM) which resides in the pedestal region, has been achieved in the EAST tokamak recently. This regime allows the operation of a nearly fully noninductive long pulse (>15 s), exhibiting a relatively high pedestal and good global energy confinement with {{H}98,y2} near 1.2, and excellent impurity control. Furthermore, this regime is mostly obtained with a 4.6 GHz lower hybrid current drive (LHCD) or counter-current neutral beam injection (NBI), plus electron cyclotron resonance heating, and an extensive lithium wall coating. This stationary ELM-absent H-mode regime transits to a stationary small ELM H-mode regime, and upon additional heating power from the 2.45 GHz LHCD, an ion cyclotron resonant frequency or co-current NBI is applied (under 4.6 GHz LHCD heating background). A slight change of the plasma configuration also makes the small ELMs reappear. The experimental observations suggest that a long-pulse ELM-absent regime can be induced by the ECM, which exhibits strong electrostatic fluctuations and may provide a channel for continuous particle (especially impurities) and heat exhaust across the pedestal. The ECM exists in the collisionality of ν e*   =  2.5-4 and the pressure gradient |\

  15. Nonlinear simulation of ELM dynamics in the presence of resonant magnetic perturbations

    NASA Astrophysics Data System (ADS)

    Chandra, D.; Thyagaraja, A.; Sen, A.; Kaw, P.

    2017-07-01

    We report on nonlinear simulation studies on the dynamical behaviour of ELMs under the influence of resonant magnetic perturbations (RMPs) using a two-fluid initial value electromagnetic nonlinear global code (CUTIE). To simulate ELMs we introduce a particle source in the confinement region and a particle sink in the edge region. To study ELM control using RMPs we have applied an n  =  2 static external magnetic perturbation at the edge and made detailed parametric studies under varying conditions for the machine and plasma parameters typical of COMPASS-D. Our results show that ELM mitigation is possible for RMP powers beyond a specific threshold. The results also provide valuable insights into the RMP induced modifications of the complex nonlinear dynamics of the ELMs, in particular on the redistribution of mode energy and the cascading of energy to shorter scale lengths. We also observe a hysteresis in states as we increase the amplitude of RMPs and then decrease it to the same value.

  16. Broadening of divertor heat flux profile with increasing number of ELM filaments in NSTX

    NASA Astrophysics Data System (ADS)

    Ahn, J.-W.; Maingi, R.; Canik, J. M.; Gan, K. F.; Gray, T. K.; McLean, A. G.

    2014-12-01

    Edge localized modes (ELMs) represent a challenge to future fusion devices, owing to cyclical high peak heat fluxes on divertor plasma facing surfaces. One ameliorating factor has been that the heat flux characteristic profile width has been observed to broaden with the size of the ELM, as compared with the inter-ELM heat flux profile. In contrast, the heat flux profile has been observed to narrow during ELMs under certain conditions in NSTX. Here we show that the ELM heat flux profile width increases with the number of filamentary striations observed, i.e. profile narrowing is observed with zero or very few striations. Because NSTX often lies on the long wavelength current-driven mode side of ideal MHD instabilities, few filamentary structures can be expected under many conditions. ITER is also projected to lie on the current driven low-n stability boundary, and therefore detailed projections of the unstable modes expected in ITER and the heat flux driven in ensuing filamentary structures is needed.

  17. Turbulence, flows and edge localized mode (ELM) dynamics in limiter H-mode plasmas in TEXTOR

    NASA Astrophysics Data System (ADS)

    Soldatov, S.; Krämer-Flecken, A.; Kantor, M.; Unterberg, B.; Sun, Y.; Van Oost, G.; Reiter, D.; TEXTOR Team

    2010-08-01

    The turbulence, plasma flow and edge localized mode (ELM) dynamics in the limiter H-mode TEXTOR plasmas are investigated. Properties of both ambient turbulence within 0 < k⊥ < 4.2 cm-1 and coherent modes are studied on the ELM time scale in detail. The turbulence level near the pedestal is shown to evolve several times with the period of ELMs. Within the inter-ELM period the 'silent stage' is found which is characterized by an extremely low (below that for Ohmic plasmas) turbulence level and a phase growth in the reflectometry signal. The silent stage is associated with the quasi-steady state when the pedestal is formed and confinement is improved between two successive ELMs. Quasi-coherent density oscillations near the pedestal region with m ≈ 3, 5, 16 and 38 are measured with correlation reflectometry. Low-m modes are found to reveal the signatures of precursor mode. At first, the radial structure of the rotation shear and radial electric field Er in limiter H-mode in TEXTOR is presented. The characteristic negative electric field well with the sharp gradient ∇Er ≈ 250 V cm-2 at ≈2 cm inside separatrix is resolved. The Er × B rotation profile defines both the resulting plasma rotation in the electron diamagnetic drift direction and a significant rotation shear near the separatrix which exceeds the decorrelation rate of ambient turbulence by several times.

  18. Broadening of divertor heat flux profile with increasing number of ELM filaments in NSTX

    SciTech Connect

    Ahn, J. -W.; Maingi, R.; Canik, J. M.; Gan, K. F.; Gray, T. K.; McLean, A. G.

    2014-11-13

    Edge localized modes (ELMs) represent a challenge to future fusion devices, owing to cyclical high peak heat fluxes on divertor plasma facing surfaces. One ameliorating factor has been that the heat flux characteristic profile width has been observed to broaden with the size of the ELM, as compared with the inter-ELM heat flux profile. In contrast, the heat flux profile has been observed to narrow during ELMs under certain conditions in NSTX. Here we show that the ELM heat flux profile width increases with the number of filamentary striations observed, i.e., profile narrowing is observed with zero or very few striations. Because NSTX often lies on the long wavelength current-driven mode side of ideal MHD instabilities, few filamentary structures can be expected under many conditions. Lastly, ITER is also projected to lie on the current driven low-n stability boundary, and therefore detailed projections of the unstable modes expected in ITER and the heat flux driven in ensuing filamentary structures is needed.

  19. ELM Behavior in High- βp EAST-Demonstration Plasmas on DIII-D

    NASA Astrophysics Data System (ADS)

    Li, G. Q.; Gong, X. Z.; Garofalo, A. M.; Lao, L. L.; Meneghini, O.; Snyder, P. B.; Ren, Q. L.; Ding, S. Y.; Guo, W. F.; Qian, J. P.; Wan, B. N.; Xu, G. S.; Holcomb, C. T.; Solomon, W. M.

    2015-11-01

    In the DIII-D high- βp EAST-demonstration experiment, for several similar discharges when the experimental parameters such as the toroidal magnetic field or ECH power are varied slightly, the changes in ELM frequency response are observed to be much larger. Kinetic EFIT equilibrium reconstructions for these discharges have been performed, which suggest that the ELM frequency changes are likely due to the variations of pedestal width, height, and edge current density. Kinetic profile analyses further indicate that the strong ITB that are located at large minor radii (rho=0.6 ~0.7) in these discharges are affecting the pedestal structure. The ITB could broaden the pedestal width and decrease the pedestal height, thus changing the ELM frequency and size. With the GATO and ELITE MHD codes, the linear growth rates and mode structures of these ELMs are analyzed. The impact of ITB on the ELMs behavior will be discussed. Work supported by China MOST under 2014GB106001 and 2015GB102001 and US DOE under DE-FC02-04ER54698 and DE-FG03-95ER54309.

  20. DRP3 and ELM1 are required for mitochondrial fission in the liverwort Marchantia polymorpha.

    PubMed

    Nagaoka, Nagisa; Yamashita, Akihiro; Kurisu, Rina; Watari, Yuta; Ishizuna, Fumiko; Tsutsumi, Nobuhissro; Ishizaki, Kimitsune; Kohchi, Takayuki; Arimura, Shin-Ichi

    2017-07-04

    Mitochondria increase in number by the fission of existing mitochondria. Mitochondrial fission is needed to provide mitochondria to daughter cells during cell division. In Arabidopsis thaliana, four kinds of genes have been reported to be involved in mitochondrial fission. Two of them, DRP3 (dynamin-related protein3) and FIS1 (FISSION1), are well conserved in eukaryotes. The other two are plant-specific ELM1 (elongated mitochondria1) and PMD (peroxisomal and mitochondrial division). To better understand the commonality and diversity of mitochondrial fission factors in land plants, we examined mitochondrial fission-related genes in a liverwort, Marchantia polymorpha. As a bryophyte, M. polymorpha has features distinct from those of the other land plant lineages. We found that M. polymorpha has single copies of homologues for DRP3, FIS1 and ELM1, but does not appear to have a homologue of PMD. Citrine-fusion proteins with MpDRP3, MpFIS1 and MpELM1 were localized to mitochondria in M. polymorpha. MpDRP3- and MpELM1-defective mutants grew slowly and had networked mitochondria, indicating that mitochondrial fission was blocked in the mutants, as expected. However, knockout of MpFIS1 did not affect growth or mitochondrial morphology. These results suggest that MpDRP3 and MpELM1 but neither MpFIS1 nor PMD are needed for mitochondrial fission in M. polymorpha.

  1. Comparative investigation of ELM control based on toroidal modelling of plasma response to RMP fields

    NASA Astrophysics Data System (ADS)

    Liu, Yueqiang; Kirk, A.; Li, Li; In, Y.; Nazikian, R.; Sun, Youwen; Suttrop, W.; Lyons, B.; Ryan, D.; Wang, Shuo; Yang, Xu; Zhou, Lina

    2017-05-01

    Extensive modelling efforts of the plasma response to the resonant magnetic perturbation fields, utilized for controlling the edge localized mode (ELM), help to identify the edge-peeling response as a key factor, which correlates to the observed ELM mitigation in several tokamak devices, including MAST, ASDEX Upgrade, EAST, and HL-2A. The recently observed edge safety factor window for ELM mitigation in HL-2A experiments is explained in terms of the edge-peeling response. The computed plasma response, based on toroidal single fluid resistive plasma model with different assumption of toroidal flows, is found generally larger in ELM suppressed cases as compared to that of the ELM mitigated cases, in ASDEX Upgrade and DIII-D. The plasma shaping, in particular, the plasma triangularity, contributes to the enhanced plasma response. But the shaping does not appear to be the sole factor—other factors such as the (higher) pedestal pressure and/or current can also lead to increased edge-peeling response.

  2. ELM Suppression in DIII-D ITER-like Plasmas Using n = 2 Magnetic Perturbations

    NASA Astrophysics Data System (ADS)

    Nazikian, R.; Grierson, B. A.; Okabayashi, M.; Tobias, B. J.; Eldon, D.; Evans, T. E.; Ferraro, N. M.; Groebner, R. J.; Paz-Soldan, C.; Strait, E. J.; Haskey, S. R.; King, J. D.; McKee, G. R.; Moyer, R. A.; Orlov, D. M.; Shafer, M. W.

    2014-10-01

    A robust window of edge localized mode (ELM) suppression was observed at elevated magnetic safety factor (q95 ~ 4.1) in ITER-like plasmas with even parity n = 2 resonant magnetic perturbation (RMP) using the internal I-coils. Variation of the upper and lower I-coil phasing was used to explore the importance of pitch alignment vs kink alignment for ELM suppression. Both the pedestal density and ELM suppression were strongly dependent on I-coil phasing and a large variation in the plasma response amplitude was measured on multiple diagnostics. Surprisingly, toroidal rotation of the even parity n = 2 RMP led to the loss of ELM suppression, indicating that components of the residual error field orthogonal to the kink mode may be important near the threshold for ELM suppression. Work supported by the US Department of Energy under DE-AC02-09CH11466, DE-FC02-04ER54698, DE-AC05-06OR23100, DE-FG02-89ER53296, DE-FG02-08ER54999, DE-FG02-07ER54917, and DE-AC05-00OR22725.

  3. Comparison of Plasma Parameters Between QH and ELMing Phases of the Same Discharges

    SciTech Connect

    Lasnier, C; West, W; Burrell, K; deGrassie, J; Doyle, E; Osborne, T

    2004-05-24

    H-mode confinement is observed for many energy confinement times without edge localized modes (ELMs) in QH (quiescent high-confinement)-mode discharges in DIII-D. To find critical differences between ELMing and QH modes we compared electron temperature (T{sub e}), density (n{sub e}), and ion temperature (T{sub i}), in the pedestal and scrape-off layer (SOL) for a group of discharges. We also compared the electron pressures P{sub ped}, and maximum pressure gradients P{sub e,ped,max grad} because of their importance in confinement and stability. Experimental results show that the core line averaged density, median T{sub e} (pedestal), SOL T{sub e}, and T{sub e} pedestal width, and SOL T{sub i} are nearly the same in QH mode as that during ELMs. The n{sub e} (average pedestal), n{sub e} pedestal width, P{sub ped}, and P{sub e,ped,max grad} are similar to corresponding values in QH mode and at various times between ELMs. However, the pedestal T{sub i} is 1.6 times higher in QH mode than during ELMing.

  4. Will Dutch Become Flemish? Autonomous Developments in Belgian Dutch

    ERIC Educational Resources Information Center

    Van de Velde, Hans; Kissine, Mikhail; Tops, Evie; van der Harst, Sander; van Hout, Roeland

    2010-01-01

    In this paper a series of studies of standard Dutch pronunciation in Belgium and the Netherlands is presented. The research is based on two speech corpora: a diachronic corpus of radio speech (1935-1995) and a synchronic corpus of Belgian and Netherlandic standard Dutch from different regions at the turn of the millennium. It is shown that two…

  5. Will Dutch Become Flemish? Autonomous Developments in Belgian Dutch

    ERIC Educational Resources Information Center

    Van de Velde, Hans; Kissine, Mikhail; Tops, Evie; van der Harst, Sander; van Hout, Roeland

    2010-01-01

    In this paper a series of studies of standard Dutch pronunciation in Belgium and the Netherlands is presented. The research is based on two speech corpora: a diachronic corpus of radio speech (1935-1995) and a synchronic corpus of Belgian and Netherlandic standard Dutch from different regions at the turn of the millennium. It is shown that two…

  6. Elm1 kinase activates the spindle position checkpoint kinase Kin4.

    PubMed

    Caydasi, Ayse Koca; Kurtulmus, Bahtiyar; Orrico, Maria I L; Hofmann, Astrid; Ibrahim, Bashar; Pereira, Gislene

    2010-09-20

    Budding yeast asymmetric cell division relies upon the precise coordination of spindle orientation and cell cycle progression. The spindle position checkpoint (SPOC) is a surveillance mechanism that prevents cells with misoriented spindles from exiting mitosis. The cortical kinase Kin4 acts near the top of this network. How Kin4 kinase activity is regulated and maintained in respect to spindle positional cues remains to be established. Here, we show that the bud neck-associated kinase Elm1 participates in Kin4 activation and SPOC signaling by phosphorylating a conserved residue within the activation loop of Kin4. Blocking Elm1 function abolishes Kin4 kinase activity in vivo and eliminates the SPOC response to spindle misalignment. These findings establish a novel function for Elm1 in the coordination of spindle positioning with cell cycle progression via its control of Kin4.

  7. Collapse of density pedestal by giant ELM on JT-60U

    NASA Astrophysics Data System (ADS)

    Oyama, N.; Shinohara, K.; Kamada, Y.; Miura, Y.; Oikawa, T.; Takeji, S.

    2001-05-01

    In JT-60U ELMy H-mode discharges, the detailed behaviour of giant (type I) ELMs was measured using a heterodyne reflectometer system in order to understand the collapse mechanism of the pedestal structure and consequences on the core/edge plasma. The phase signal of the reflectometer exhibits the movement of the cutoff layer (density layer) due to the collapse of the pedestal in a density profile by an ELM. An ELM event can be classified into a precursor phase, collapse phase, recovery phase and a relaxation phase. A certain density layer measured near the shoulder of the pedestal moves about 7 cm inside the plasma in the collapse phase. The precursor oscillation in a pedestal density and the relationship between the collapse of the pedestal structure and a Dα burst are also studied.

  8. New Grid of Models for ELM WDs Including Element Diffusion and Rotational Mixing

    NASA Astrophysics Data System (ADS)

    Istrate, A. G.

    2017-03-01

    We present our latest results for the modelling of extremely low-mass white dwarfs (ELM WDs) in which, for the first time, we study the combined effects of rotational mixing and element diffusion. In particular, we investigate how their general properties, such as their evolutionary timescales, the hydrogen envelope mass and their surface composition are affected compared to the case when just element diffusion is included. The formation of ELM WDs through the LMXB channel in environments with different metallicities is modelled using the state-of-the-art stellar evolution code MESA. Rotational mixing is found to counteract the effect of gravitational settling in the surface of young, bloated ELM proto-WDs suggesting that it is the key process needed to explain the observed metals (especially calcium) abundances in their atmospheres.

  9. Compound feature selection and parameter optimization of ELM for fault diagnosis of rolling element bearings.

    PubMed

    Luo, Meng; Li, Chaoshun; Zhang, Xiaoyuan; Li, Ruhai; An, Xueli

    2016-11-01

    This paper proposes a hybrid system named as HGSA-ELM for fault diagnosis of rolling element bearings, in which real-valued gravitational search algorithm (RGSA) is employed to optimize the input weights and bias of ELM, and the binary-valued of GSA (BGSA) is used to select important features from a compound feature set. Three types fault features, namely time and frequency features, energy features and singular value features, are extracted to compose the compound feature set by applying ensemble empirical mode decomposition (EEMD). For fault diagnosis of a typical rolling element bearing system with 56 working condition, comparative experiments were designed to evaluate the proposed method. And results show that HGSA-ELM achieves significant high classification accuracy compared with its original version and methods in literatures.

  10. Biomass properties and gasification behavior of 7-year-old Siberian elm

    SciTech Connect

    Geyer, W.A.; Argent, R.M.; Walawender, W.P.

    1987-04-01

    Studies were conducted to establish baseline information for use in characterizing Siberian elm as energy or fiber feedstock. Biomass properties were determined. Calorific value (4698 cal/g) and specific gravity (0.55) of Siberian elm are similar to those of soft elms, and its fiber length is relatively short (1.00 mm). Ash content was 1.65%. Gasification produces a medium energy gas (3 x 10/sup 6/ cal/cubic m) with yield varying from 0.17 to 0.96 cubic m/kg over a gasification temperature range of 600 to 700 C. Oven-dry yields were 9.8 t/ha annually at 700 trees/ha. 23 references.

  11. Elm1 kinase activates the spindle position checkpoint kinase Kin4

    PubMed Central

    Caydasi, Ayse Koca; Kurtulmus, Bahtiyar; Orrico, Maria I.L.; Hofmann, Astrid; Ibrahim, Bashar

    2010-01-01

    Budding yeast asymmetric cell division relies upon the precise coordination of spindle orientation and cell cycle progression. The spindle position checkpoint (SPOC) is a surveillance mechanism that prevents cells with misoriented spindles from exiting mitosis. The cortical kinase Kin4 acts near the top of this network. How Kin4 kinase activity is regulated and maintained in respect to spindle positional cues remains to be established. Here, we show that the bud neck–associated kinase Elm1 participates in Kin4 activation and SPOC signaling by phosphorylating a conserved residue within the activation loop of Kin4. Blocking Elm1 function abolishes Kin4 kinase activity in vivo and eliminates the SPOC response to spindle misalignment. These findings establish a novel function for Elm1 in the coordination of spindle positioning with cell cycle progression via its control of Kin4. PMID:20855503

  12. A novel classification method based on ICA and ELM: a case study in lie detection.

    PubMed

    Xiong, Yijun; Luo, Yu; Huang, Wentao; Zhang, Wenjia; Yang, Yong; Gao, Junfeng

    2014-01-01

    The classification of EEG tasks has drawn much attention in recent years. In this paper, a novel classification model based on independent component analysis (ICA) and Extreme learning machine (ELM) is proposed to detect lying. Firstly, ICA and its topography information were used to automatically identify the P300 ICs. Then, time and frequency-domain features were extracted from the reconstructed P3 waveforms. Finally, two classes of feature samples were used to train ELM, Back-propagation network (BPNN) and support vector machine (SVM) classifiers for comparison. The optimal number of P3 ICs and the values of classifier parameter were optimized by the cross-validation procedures. Experimental results show that the presented method (ICA_ELM) achieves the highest training accuracy of 95.40% with extremely less training and testing time on detecting P3 components for the guilty and the innocent subjects. The results indicate that the proposed method can be applied in lie detection.

  13. Half a century of Dutch transplant immunology.

    PubMed

    van Rood, Jon J; Claas, Frans H J; Brand, Anneke; Tilanus, Marcel G J; van Kooten, Cees

    2014-12-01

    The sixties have not only witnessed the start of the Dutch Society for Immunology (NvvI), but were also the flourishing beginning of the discipline of transplant immunology. The interest in immunology in the Netherlands had its start in the context of blood transfusions and not for instance in the field of infectious disease, as in many other countries. It began in the 1950-ties thanks to Joghem van Loghem at that time director of the Central Laboratory of Blood Transfusion in Amsterdam. The discoveries of these times have had major impact for transfusion medicine, hematopoietic stem cell transplantation and organ transplantation. In this review we will look back at some early highlights of Dutch transplant immunology and put them in the perspective of some recent developments.

  14. Semiochemical-MediatedFlight Strategies of Two Invasive Elm Bark Beetles: A Potential Factor in Competitive Displacement

    USDA-ARS?s Scientific Manuscript database

    A recent seven-state survey revealed that the newly invasive banded elm bark beetle, Scolytus schevyrewi, was abundant in areas of Colorado and Wyoming, USA, whereas the long-established European elm bark beetle, S. multistriatus was not as abundant. Behavioral trials were conducted by hanging sm...

  15. Co-occurrence of the invasive banded and European elm bark beetles (Coleoptera: Scolytidae) in North America

    Treesearch

    Janna C. Lee; Ingrid Aguayo; Ray Aslin; Gail Durham; Shakeeb M. Hamud; Beruce D. Moltzan; A. Steve Munson; Jose F. Negron; Travis Peterson; Iral R. Ragenovich; Jeffrey J. Witcosky; Steven J. Seybold

    2009-01-01

    The invasive European elm bark beetle, Scolytus multistriatus (Marsham), was detected in Massachusetts a century ago, and it now occurs throughout the continental United States and southern Canada. The Asian banded elm bark beetle, Scolytus schevyrewi Semenov, was discovered in the United States in 2003, and now occurs in 28 states...

  16. Improving germination of red elm (Ulmus rubra), gray alder (Alnus incana), and buffaloberry (Shepherdia canadensis) seeds with gibberellic acid

    Treesearch

    Brenda Morales; Charles Barden; Cheryl Boyer; Jason Griffin; Lillian Fisher; Joni Thompson

    2012-01-01

    Red elm (Ulmus rubra), gray alder (Alnus incana), and buffaloberry (Shepherdia canadensis) are considered important plants for many Native American tribes in the United States. Native Americans use these 3 species for a variety of traditional and medicinal purposes. For example, red elm is still the preferred firewood for the cultural ceremonies of several tribes....

  17. Explaining Electronic Learning Management Systems (ELMS) Continued Usage Intentions among Facilitators in Higher Education Institutions (HEIs) in Tanzania

    ERIC Educational Resources Information Center

    Muries, Bruckse; Masele, Juma James

    2017-01-01

    This study sought to explain ELMS continued usage intentions among HEIs in Tanzania. The study was guided by main research question, "What explains ELMS continued usage intentions among facilitators in HEIs in Tanzania?" The study used descriptive cross sectional design administered to 264 respondents drawn from five universities…

  18. Semiochemical-mediated flight strategies of two invasive elm bark beetles: A potential factor in competitive displacement

    Treesearch

    Jana C. Lee; Shakeeb M. Hamud; Jose F. Negron; Jeffrey J. Witcosky; Steven J. Seybold

    2010-01-01

    A seven-state survey showed that the recently detected invasive Asian banded elm bark beetle, Scolytus schevyrewi Semenov, was abundant in areas of Colorado and Wyoming, whereas the long-established European elm bark beetle, S. multistriatus (Marsham), was not as abundant. In one of a series of studies to evaluate whether S. schevyrewi is competitively displacing S....

  19. Numerical Analysis of the Effects of Normalized Plasma Pressure on RMP ELM Suppression in DIII-D

    SciTech Connect

    Orlov, D. M.; Moyer, R.A.; Evans, T. E.; Mordijck, S.; Osborne, T. H.; Fenstermacher, M. E.; Snyder, P. B.; Unterberg, Ezekial A

    2010-01-01

    The effect of normalized plasma pressure as characterized by normalized pressure parameter (beta(N)) on the suppression of edge localized modes (ELMs) using resonant magnetic perturbations (RMPs) is studied in low-collisionality (nu* <= 0.2) H-mode plasmas with low-triangularity ( = 0.25) and ITER similar shapes ( = 0.51). Experimental results have suggested that ELM suppression by RMPs requires a minimum threshold in plasma pressure as characterized by beta(N). The variations in the vacuum field topology with beta(N) due to safety factor profile and island overlap changes caused by variation of the Shafranov shift and pedestal bootstrap current are examined numerically with the field line integration code TRIP3D. The results show very small differences in the vacuum field structure in terms of the Chirikov (magnetic island overlap) parameter, Poincare sections and field line loss fractions. These differences do not appear to explain the observed threshold in beta(N) for ELM suppression. Linear peeling-ballooning stability analysis with the ELITE code suggests that the ELMs which persist during the RMPs when beta(N) is below the observed threshold are not type I ELMs, because the pedestal conditions are deep within the stable regime for peeling-ballooning modes. These ELMs have similarities to type III ELMs or low density ELMs.

  20. Toroidal Rotation and 3D Nonlinear Dynamics in the Peeling-Ballooning Model of ELMs

    NASA Astrophysics Data System (ADS)

    Snyder, P. B.

    2004-11-01

    Maximizing the height of the edge transport barrier (or ``pedestal'') while maintaining acceptably small edge localized modes (ELMs) is a critical issue for tokamak performance. The peeling-ballooning model proposes that intermediate wavelength MHD instabilities are responsible for ELMs and impose constraints on the pedestal. Recent studies of linear peeling-ballooning stability have found encouraging agreement with observations [e.g. 1]. To allow more detailed prediction of mode characteristics, including eventually predictions of the ELM energy loss and its deposition, we consider effects of sheared toroidal rotation, as well as 3D nonlinear dynamics. An eigenmode formulation for toroidal rotation shear is developed and incorporated into the framework of the ELITE stability code [2], resolving the low rotation discontinuity in previous high-n results. Rotation shear is found to impact the structure of peeling-ballooning modes, causing radial narrowing and mode shearing. The calculated mode frequency is found to agree with observed rotation in the edge region in the early stages of the ELM crash. Nonlinear studies with the 3D BOUT and NIMROD codes reveal detailed characteristics of the early evolution of these edge instabilities, including the impact of non-ideal effects. The expected linear growth phase is followed by a fast crash event in which poloidally narrow, filamentary structures propagate radially outward from the pedestal region, closely resembling observed ELM events. Comparisons with ELM observations will be discussed. \\vspace0.25em [1] P.B. Snyder et al., Nucl. Fusion 44, 320 (2004); P.B. Snyder et al., Phys. Plasmas 9, 2037 (2002). [2] H.R. Wilson et al., Phys. Plasmas 9, 1277 (2002).

  1. Pedestal Characterization and Stability of Small-ELM Regimes in NSTX

    SciTech Connect

    Sontag, Aaron C; Canik, John; Maingi, Rajesh; Manickam, J.; Snyder, P.; Bell, R. E.; Gerhardt, S.P.; Kubota, S.; LaBlanc, B. P.; Mueller, D.; Osborne, T.; Tritz, K.

    2010-01-01

    An instability near the plasma edge known as the edge harmonic oscillation (EHO) is thought to enable access to the ELM-free quiescent H-mode (QH-mode) in tokamaks, which is a highly desirable operational regime for ITER because of the avoidance of periodic ELM heat loads. The EHO has been hypothesized to be a saturated kink driven unstable by toroidal rotational shear that provides sufficient transport near the plasma edge to keep the edge plasma below the peeling-ballooning stability limit. NSTX has observed unstable modes with similar characteristics to the EHO coincident with transition to a small-ELM regime (called Type-V). These small ELMs do not have a measurable effect on the plasma stored energy (< 1%). Transition to this regime is associated with a downward biased plasma as evidenced by drsep < -5 mm. Soft x-ray emission indicates that these modes are localized just inside the pedestal and are correlated with increased density fluctuations in the pedestal as measured by microwave reflectometry. The lowest order mode rotates at the plasma rotation frequency, indicating n=1, and harmonics up to n=6 have been observed simultaneously with the n=1, as determined by the rotation frequency of the higher harmonics. Increased edge collisionality is required to access Type-V ELMs. Stability analysis during the observed modes indicates instability to n=1-3 with n=3 having the highest growth rate and unstable mode eigenfunctions peaked near the plasma edge. Discharges with Type-V and Type-I ELMs are both calculated to be on the peeling unstable side of the peeling ballooning stability curve, with the Type-V case at higher normalized pressure gradient.

  2. Pedestal characterization and stability of small-ELM regimes in NSTX

    SciTech Connect

    Sontag, Aaron C; Canik, John; Maingi, Rajesh; Manickam, J.; Snyder, P.; Bell, R. E.; Gerhardt, S.P.; Kubota, S.; LaBlanc, B. P.; Mueller, D.; Osborne, T.; Tritz, K.

    2011-01-01

    An instability near the plasma edge known as the edge harmonic oscillation (EHO) is thought to enable access to the ELM-free quiescent H-mode (QH-mode) in tokamaks, which is a highly desirable operational regime for ITER because of the avoidance of periodic ELM heat loads. The EHO has been hypothesized to be a saturated kink driven unstable by toroidal rotational shear that provides sufficient transport near the plasma edge to keep the edge plasma below the peeling-ballooning stability limit. NSTX has observed unstable modes with similar characteristics to the EHO coincident with transition to a small-ELM regime (called Type-V). These small ELMs do not have a measurable effect on the plasma stored energy (< 1%). Transition to this regime is associated with a downward biased plasma as evidenced by drsep < -5 mm. Soft x-ray emission indicates that these modes are localized just inside the pedestal and are correlated with increased density fluctuations in the pedestal as measured by microwave reflectometry. The lowest order mode rotates at the plasma rotation frequency, indicating n=1, and harmonics up to n=6 have been observed simultaneously with the n=1, as determined by the rotation frequency of the higher harmonics. Increased edge collisionality is required to access Type-V ELMs. Stability analysis during the observed modes indicates instability to n=1-3 with n=3 having the highest growth rate and unstable mode eigenfunctions peaked near the plasma edge. Discharges with Type-V and Type-I ELMs are both calculated to be on the peeling unstable side of the peeling ballooning stability curve, with the Type-V case at higher normalized pressure gradient.

  3. QUANTITATIVE TESTS OF ELMS AS INTERMEDIATE N PEELING-BALLOONING MODES

    SciTech Connect

    LAO, LL; SNYDER, PB; LEONARD, AW; OSBORNE, TH; PETRIE, TW; FERRON, JR; GROEBNER, RJ; HORTON, LD; KAMADA, Y; MURAKAMI, M; OIKAWA, T; PEARLSTEIN, LD; SAARELMA, S; STJOHN, HE; THOMAS, DM; TURNBULL, AD; WILSON, HR

    2002-07-01

    OAK A271 QUANTITATIVE TESTS OF ELMS AS INTERMEDIATE N PEELING-BALLOONING MODES. Two of the major issues crucial for the design of the next generation tokamak burning plasma devices are the predictability of the edge pedestal height and control of the divertor heat load in H-mode configurations. Both of these are strongly impacted by edge localized modes (ELMs) and their size. A working model for ELMs is that they are intermediate toroidal mode number, n {approx} 5-30, peeling-ballooning modes driven by the large edge pedestal pressure gradient P{prime} and the associated large edge bootstrap current density J{sub BS}. the interplay between P{prime} and J{sub BS} as a discharge evolves can excite peeling-ballooning modes over a wide spectrum of n. The pedestal current density plays a dual role by stabilizing the high n ballooning modes via opening access to second stability but providing free energy to drive the intermediate n peeling modes. This makes a systematic evaluation of this model particularly challenging. This paper describes recent quantitative tests of this model using experimental data from the DIII-D and the JT-60U tokamaks. These tests are made possible by recent improvements to the ELITE MHD stability code, which allow an efficient evaluation of the unstable peeling-ballooning modes, as well as by improvements to other diagnostic and analysis techniques. Some of the key testable features of this model are: (1) ELMs are triggered when the growth rates of intermediate n MHD modes become significantly large; (2) ELM sizes are related to the radial widths of the unstable modes; (3) the unstable modes have a strong ballooning character localized in the outboard bad curvature region; (4) at high collisionality, ELM size generally becomes smaller because J{sub BS} is reduced.

  4. Regulation of dimorphism in Saccharomyces cerevisiae: involvement of the novel protein kinase homolog Elm1p and protein phosphatase 2A.

    PubMed Central

    Blacketer, M J; Koehler, C M; Coats, S G; Myers, A M; Madaule, P

    1993-01-01

    The Saccharomyces cerevisiae genes ELM1, ELM2, and ELM3 were identified on the basis of the phenotype of constitutive cell elongation. Mutations in any of these genes cause a dimorphic transition to a pseudohyphal growth state characterized by formation of expanded, branched chains of elongated cells. Furthermore, elm1, elm2, and elm3 mutations cause cells to grow invasively under the surface of agar medium. S. cerevisiae is known to be a dimorphic organism that grows either as a unicellular yeast or as filamentous cells termed pseudohyphae; although the yeast-like form usually prevails, pseudohyphal growth may occur during conditions of nitrogen starvation. The morphologic and physiological properties caused by elm1, elm2, and elm3 mutations closely mimic pseudohyphal growth occurring in conditions of nitrogen starvation. Therefore, we propose that absence of ELM1, ELM2, or ELM3 function causes constitutive execution of the pseudohyphal differentiation pathway that occurs normally in conditions of nitrogen starvation. Supporting this hypothesis, heterozygosity at the ELM2 or ELM3 locus significantly stimulated the ability to form pseudohyphae in response to nitrogen starvation. ELM1 was isolated and shown to code for a novel protein kinase homolog. Gene dosage experiments also showed that pseudohyphal differentiation in response to nitrogen starvation is dependent on the product of CDC55, a putative B regulatory subunit of protein phosphatase 2A, and a synthetic phenotype was observed in elm1 cdc55 double mutants. Thus, protein phosphorylation is likely to regulate differentiation into the pseudohyphal state. Images PMID:8395007

  5. Pennsylvania Dutch Crafts and Culture

    ERIC Educational Resources Information Center

    Turner, Dianne

    2008-01-01

    Many people hold two common misconceptions about the Pennsylvania Dutch: first, that these people live exclusively in the state of Pennsylvania; second, that their ancestors came from Holland. However, neither assumption is correct. One can find large Pennsylvania Dutch communities in Mary land, West Virginia, Virginia, the Carolinas, Ohio,…

  6. Pennsylvania Dutch Crafts and Culture

    ERIC Educational Resources Information Center

    Turner, Dianne

    2008-01-01

    Many people hold two common misconceptions about the Pennsylvania Dutch: first, that these people live exclusively in the state of Pennsylvania; second, that their ancestors came from Holland. However, neither assumption is correct. One can find large Pennsylvania Dutch communities in Mary land, West Virginia, Virginia, the Carolinas, Ohio,…

  7. The Extent of Hybridization and Its Impact on the Genetic Diversity and Population Structure of an Invasive Tree, Ulmus Pumila (Ulmaceae)

    USDA-ARS?s Scientific Manuscript database

    Siberian elm (Ulmus pumila L.), native to East Asia, was introduced in the U.S. in the 1900’s because of its high tolerance to Dutch elm disease (DED). Siberian elm has spread following its introduction and has now become one of the most invasive woody species in the U.S., alongside Russian olive a...

  8. Ulmus americana is a polyploid complex

    USDA-ARS?s Scientific Manuscript database

    The elms (the genus Ulmus) are one of the most important tree crops for the $4.7-billion per year nursery industry. The commercial importance of the genus centers on the American elm, Ulmus americana. Once decimated by Dutch Elm Disease, the recent introduction of cultivars resistant to the diseas...

  9. Comparative investigation of ELM control based on toroidal modelling of plasma response to RMP fields

    NASA Astrophysics Data System (ADS)

    Liu, Yueqiang

    2016-10-01

    The type-I edge localized mode (ELM), bursting at low frequency and with large amplitude, can channel a substantial amount of the plasma thermal energy into the surrounding plasma-facing components in tokamak devices operating at the high-confinement mode, potentially causing severe material damages. Learning effective ways of controlling this instability is thus an urgent issue in fusion research, in particular in view of the next generation large devices such as ITER and DEMO. Among other means, externally applied, three-dimensional resonant magnetic perturbation (RMP) fields have been experimentally demonstrated to be successful in mitigating or suppressing the type-I ELM, in multiple existing devices. In this work, we shall report results of a comparative study of ELM control using RMPs. Comparison is made between the modelled plasma response to the 3D external fields and the observed change of the ELM behaviour on multiple devices, including MAST, ASDEX Upgrade, EAST, DIII-D, JET, and KSTAR. We show that toroidal modelling of the plasma response, based on linear and quasi-linear magnetohydrodynamic (MHD) models, provides essential insights that are useful in interpreting and guiding the ELM control experiments. In particular, linear toroidal modelling results, using the MARS-F code, reveal the crucial role of the edge localized peeling-tearing mode response during ELM mitigation/suppression on all these devices. Such response often leads to strong peaking of the plasma surface displacement near the region of weak equilibrium poloidal field (e.g. the X-point), and this provides an alternative practical criterion for ELM control, as opposed to the vacuum field based Chirikov criteria. Quasi-linear modelling using MARS-Q provides quantitative interpretation of the side effects due to the ELM control coils, on the plasma toroidal momentum and particle confinements. The particular role of the momentum and particle fluxes, associated with the neoclassical toroidal

  10. Advances in the Understanding of ELM Suppression by Resonant Magnetic Perturbations (RMPs) in DIII-D and Implications for ITER

    SciTech Connect

    Nazikian, R.

    2014-09-01

    Experiments on DIII-D have expanding the operating window for RMP ELM suppression to higher q95 with dominant electron heating and fully non-inductive current drive relevant to advanced modes of ITER operation. Robust ELM suppression has also been obtained with a reduced coil set, mitigating the risk of coil failure in maintaining ELM suppression in ITER. These results significantly expand the operating space and reduce risk for obtaining RMP ELM suppression in ITER. Efforts have also been made to search for 3D cause of ELM suppression. No internal non-axisymmetric structure is detected at the top of the pedestal, indicating that the dominant effect of the RMP is to produce an n=0 transport modification of the profiles. Linear two fluid MHD simulations using M3D-C1 indicate resonant field penetration and significant magnetic stochasticity at the top of the pedestal, consistent with the absence of detectable 3D structure in that region. A profile database was developed to compare the scaling of the pedestal and global confinement with the applied 3D field strength in ELM suppressed and ELM mitigated plasmas. The EPED pedestal model accurately predicts the measured pedestal pressure at the threshold of ELM suppression, increasing confidence in theoretical projections to ITER pedestal conditions. Both the H-factor (H(sub)98y2) and thermal energy confinement time do not degrade substantially with applied RMP fields near the threshold of ELM suppression, enhancing confidence in the compatibility of ITER high performance operation with RMP ELM suppression.

  11. Investigation of ELM [edge localized mode] Dynamics with the Resonant Magnetic Perturbation Effects

    SciTech Connect

    Pankin, Alexei Y.; Kritz, Arnold H.

    2011-07-19

    Topics covered are: anomalous transport and E x B flow shear effects in the H-mode pedestal; RMP (resonant magnetic perturbation) effects in NSTX discharges; development of a scaling of H-mode pedestal in tokamak plasmas with type I ELMs (edge localized modes); and divertor heat load studies.

  12. Prediction of aromatase inhibitory activity using the efficient linear method (ELM).

    PubMed

    Shoombuatong, Watshara; Prachayasittikul, Veda; Prachayasittikul, Virapong; Nantasenamat, Chanin

    2015-01-01

    Aromatase inhibition is an effective treatment strategy for breast cancer. Currently, several in silico methods have been developed for the prediction of aromatase inhibitors (AIs) using artificial neural network (ANN) or support vector machine (SVM). In spite of this, there are ample opportunities for further improvements by developing a simple and interpretable quantitative structure-activity relationship (QSAR) method. Herein, an efficient linear method (ELM) is proposed for constructing a highly predictive QSAR model containing a spontaneous feature importance estimator. Briefly, ELM is a linear-based model with optimal parameters derived from genetic algorithm. Results showed that the simple ELM method displayed robust performance with 10-fold cross-validation MCC values of 0.64 and 0.56 for steroidal and non-steroidal AIs, respectively. Comparative analyses with other machine learning methods (i.e. ANN, SVM and decision tree) were also performed. A thorough analysis of informative molecular descriptors for both steroidal and non-steroidal AIs provided insights into the mechanism of action of compounds. Our findings suggest that the shape and polarizability of compounds may govern the inhibitory activity of both steroidal and non-steroidal types whereas the terminal primary C(sp3) functional group and electronegativity may be required for non-steroidal AIs. The R code of the ELM method is available at http://dx.doi.org/10.6084/m9.figshare.1274030.

  13. A Disposable Cage for Obtaining Individual Eggs of the Elm Spanworm

    Treesearch

    A.T. Drooz

    1969-01-01

    A waxed paper cage in the shape of a paper coffee creamer (tetrahedron) is easy to make, inexpensive, and ideal for collecting individual eggs or small groups of eggs from the egg-mass depositing elm spanworm. The moths and eggs can be readily observed through the translucent waxed paper.

  14. Some Guides to Discovery About Elm Trees, Owls, Cockroaches, Earthworms, Cement and Concrete.

    ERIC Educational Resources Information Center

    Busch, Phyllis S.

    The introduction emphasizes the need for environmental and conservation education, and advocates an inquiry approach. Outdoor resources available to every school are listed. Detailed suggestions are made for investigating cement and concrete, cockroaches, earthworms, elm trees, and owls. In each case general background information and a list of…

  15. VIEW FROM EAST SIDE OF ELM DRIVE/BIRCH CIRCLE BLOCK, SHOWING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM EAST SIDE OF ELM DRIVE/BIRCH CIRCLE BLOCK, SHOWING SLOPING TOPOGRAPHY. VIEW FACING WEST. - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  16. Using ELM-based weighted probabilistic model in the classification of synchronous EEG BCI.

    PubMed

    Tan, Ping; Tan, Guan-Zheng; Cai, Zi-Xing; Sa, Wei-Ping; Zou, Yi-Qun

    2017-01-01

    Extreme learning machine (ELM) is an effective machine learning technique with simple theory and fast implementation, which has gained increasing interest from various research fields recently. A new method that combines ELM with probabilistic model method is proposed in this paper to classify the electroencephalography (EEG) signals in synchronous brain-computer interface (BCI) system. In the proposed method, the softmax function is used to convert the ELM output to classification probability. The Chernoff error bound, deduced from the Bayesian probabilistic model in the training process, is adopted as the weight to take the discriminant process. Since the proposed method makes use of the knowledge from all preceding training datasets, its discriminating performance improves accumulatively. In the test experiments based on the datasets from BCI competitions, the proposed method is compared with other classification methods, including the linear discriminant analysis, support vector machine, ELM and weighted probabilistic model methods. For comparison, the mutual information, classification accuracy and information transfer rate are considered as the evaluation indicators for these classifiers. The results demonstrate that our method shows competitive performance against other methods.

  17. Effect of RMP spectrum on ELM suppression and the divertor plasma in KSTAR

    NASA Astrophysics Data System (ADS)

    Ahn, Joon-Wook; Park, J.-K.; in, Y.; Loarte, A.; Kim, J.; Jeon, Y. M.; Park, G. Y.; Choe, W.; Hong, J. H.; Hong, S. H.; Lee, H. H.; Kang, C. S.; Ko, W. H.; Yoon, S. W.

    2016-10-01

    ELM suppression by n =1 and n =2 magnetic perturbations have been robustly obtained in KSTAR, and effects of various coil configurations for applied magnetic perturbations (MPs) on ELM suppression as well as divertor plasma conditions have been investigated. The 4 toroidal and 3 poloidal sectors of internal coils allow to fully scan the phase difference (Δφ) of n =1 between different rows of coils, where it is shown that ideal plasma response can either shield or amplify applied MPs, depending on Δφ , which leads respectively to the weakening and strengthening of divertor footprint striations compared to the vacuum case. On the other hand, shielding is found to be the dominant plasma response for all possible cases of n =2 configuration (Δφ =0o and 90o, and mid-plane coil only), which weakens footprint striations. Spectra of applied MPs have been varied by changing Δφ as well as modifying the ratio of coil currents between different row of coils, e.g. IU/IL, in order to find optimal conditions for ELM suppression and divertor heat and particle flux dispersal. Effects of divertor conditions in various density and impurity levels on the ELM behavior and footprint striations are also being investigated. Work supported by the U.S. DOE, contract # DE-AC05-00OR22725.

  18. Pedestal density fluctuation dynamics during the inter-ELM cycle in DIII-D a)

    NASA Astrophysics Data System (ADS)

    Yan, Z.; McKee, G. R.; Groebner, R. J.; Snyder, P. B.; Osborne, T. H.; Beurskens, M. N.; Burrell, K. H.

    2011-05-01

    Detailed 2D measurements of long-wavelength density fluctuations in the pedestal region with beam emission spectroscopy during the period between edge localized modes (ELMs) indicate two distinct bands of fluctuations propagating in opposite poloidal directions in the plasma frame: one lower frequency band (50-150 kHz) advects in the ion-diamagnetic drift direction (ion mode) and a higher frequency band (200-400 kHz) advects in the electron diamagnetic drift direction (electron mode). The ion mode amplitude is modulated with the ELM cycle: it increases rapidly after an ELM and then saturates, similar to the evolution of the pedestal electron pressure and density gradients. The electron mode, in contrast, has no significant time evolution between ELMs. The decorrelation time of the ion mode is <5 μs [τc(cs/csa a)≤1], the radial correlation length is of order 10 ρi and has poloidal wave-number kθρi~0.1, and the mode advects at near the ion diamagnetic velocity in the plasma frame. These spatiotemporal dynamics are qualitatively similar to features predicted for kinetic ballooning modes.

  19. Dependence of ELM Control Using RMPs in DIII-D on Plasma Shape and Toroidal Rotation

    NASA Astrophysics Data System (ADS)

    Allen, S. L.; Fenstermacher, M. E.; Lasnier, C. J.; Evans, T. E.; Burrell, K. H.; Leonard, A. W.; Osborne, T. H.; West, W. P.; Moyer, R. A.; Joseph, I.; Watkins, J. G.

    2006-10-01

    The size and frequency of Type-I ELMs has been controlled in DIII-D H-mode plasmas using n=3 resonant magnetic perturbations (RMPs) produced by an internal coil. The operating space of ELM control has been expanded to include both low and high triangularity shapes for both low and high pedestal collisionalities. The dependence of the ELM control on density, power, plasma beta and RMP amplitude in an ITER similar shape (ISS) will be compared with previous results [1-3] in a lower average triangularity (LAT) shape. New results showing the effect of toroidal rotation on the RMP assisted ELM control will also be presented and compared with available theories [4] for the screening of the RMP fields by a rotating plasma. 6pt [1] T.E. Evans, Nat. Phys. 2, 419 (2006). [2] T.E. Evans, Phys. Plasmas 13, 056121 (2006). [3] R.A. Moyer, Phys. Plasmas 12, 056119 (2005). [4] R. Fitzpatrick, Phys. Plasmas 5, 3325 (1998)

  20. Prediction of aromatase inhibitory activity using the efficient linear method (ELM)

    PubMed Central

    Shoombuatong, Watshara; Prachayasittikul, Veda; Prachayasittikul, Virapong; Nantasenamat, Chanin

    2015-01-01

    Aromatase inhibition is an effective treatment strategy for breast cancer. Currently, several in silico methods have been developed for the prediction of aromatase inhibitors (AIs) using artificial neural network (ANN) or support vector machine (SVM). In spite of this, there are ample opportunities for further improvements by developing a simple and interpretable quantitative structure-activity relationship (QSAR) method. Herein, an efficient linear method (ELM) is proposed for constructing a highly predictive QSAR model containing a spontaneous feature importance estimator. Briefly, ELM is a linear-based model with optimal parameters derived from genetic algorithm. Results showed that the simple ELM method displayed robust performance with 10-fold cross-validation MCC values of 0.64 and 0.56 for steroidal and non-steroidal AIs, respectively. Comparative analyses with other machine learning methods (i.e. ANN, SVM and decision tree) were also performed. A thorough analysis of informative molecular descriptors for both steroidal and non-steroidal AIs provided insights into the mechanism of action of compounds. Our findings suggest that the shape and polarizability of compounds may govern the inhibitory activity of both steroidal and non-steroidal types whereas the terminal primary C(sp3) functional group and electronegativity may be required for non-steroidal AIs. The R code of the ELM method is available at http://dx.doi.org/10.6084/m9.figshare.1274030. PMID:26535037

  1. Pedestal density fluctuation dynamics during the inter-ELM cycle in DIII-D

    SciTech Connect

    Yan, Z.; McKee, G. R.; Groebner, R. J.; Snyder, P. B.; Osborne, T. H.; Burrell, K. H.; Beurskens, M. N.

    2011-05-15

    Detailed 2D measurements of long-wavelength density fluctuations in the pedestal region with beam emission spectroscopy during the period between edge localized modes (ELMs) indicate two distinct bands of fluctuations propagating in opposite poloidal directions in the plasma frame: one lower frequency band (50-150 kHz) advects in the ion-diamagnetic drift direction (ion mode) and a higher frequency band (200-400 kHz) advects in the electron diamagnetic drift direction (electron mode). The ion mode amplitude is modulated with the ELM cycle: it increases rapidly after an ELM and then saturates, similar to the evolution of the pedestal electron pressure and density gradients. The electron mode, in contrast, has no significant time evolution between ELMs. The decorrelation time of the ion mode is <5 {mu}s[{tau}{sub c}(c{sub s}/c{sub s}aa){<=}1], the radial correlation length is of order 10 {rho}{sub i} and has poloidal wave-number k{sub {theta}{rho}i{approx}}0.1, and the mode advects at near the ion diamagnetic velocity in the plasma frame. These spatiotemporal dynamics are qualitatively similar to features predicted for kinetic ballooning modes.

  2. Emission characteristics of elm bark beetle aggregation attractants from controlled-release dispensers

    Treesearch

    Roy A. Cuthbert; John W. Peacock; Susan L. Wright

    1983-01-01

    Release rates of the aggregation attractants of the smaller European elm bark beetle, Scolytus multistriatus (Marsham), from laboratory-aged and field-aged Conrel and Hercon dispensers were monitored for 85 days by GLC analysis of cold-trapped volatiles. Both dispensers had relatively low and constant rates of decay for all three attractant...

  3. Expansion of the American elm restoration effort to the upper Midwest

    Treesearch

    James M. Slavicek

    2007-01-01

    The Forestry Sciences Laboratory, Northeastern Research Station, initiated a project in 2003 to restore the American elm in the state of Ohio. This effort has been expanded to the upper Midwest through establishment of a restoration site in Decorah, IA, Eagle Island, WI, and Hastings, MN.

  4. Microbial Decomposition of Elm and Oak Leaves in a Karst Aquifer †

    PubMed Central

    Eichem, Angela C.; Dodds, Walter K.; Tate, Cathy M.; Edler, Chris

    1993-01-01

    Dry Chinquapin oak (Quercus macrocarpa) and American elm (Ulmus americana) leaves were placed in four microcosms fed by groundwater springs to monitor changes in dry mass, ash-free dry mass, and microbial activity over a 35-day period. Oxygen microelectrodes were used to measure microbial activity and to estimate millimeter-scale heterogeneity in that activity. Oak leaves lost mass more slowly than elm leaves. Generally, there was a decrease in total dry weight over the first 14 days, after which total dry weight began to increase. However, there were consistent decreases in ash-free dry mass over the entire incubation period, suggesting that the material remaining after initial leaf decomposition trapped inorganic particles. Microbial activity was higher on elm leaves than on oak leaves, with peak activity occurring at 6 and 27 days, respectively. The level of oxygen saturation on the bottom surface of an elm leaf ranged between 0 and 75% within a 30-mm2 area. This spatial heterogeneity in O2 saturation disappeared when the water velocity increased from 0 to 6 cm s-1. Our results suggest that as leaves enter the groundwater, they decompose and provide substrate for microorganisms. The rate of decomposition depends on leaf type, small-scale variations in microbial activity, water velocity, and the length of submersion time. During the initial stages of decomposition, anoxic microzones are formed that could potentially be important to the biogeochemistry of the otherwise oxic aquifer. PMID:16349078

  5. Micropropagation of juvenile and mature American elms from stem nodal sections

    Treesearch

    Ann M. Chanon; Joseph C. Kamalay; Pablo Jourdan

    1997-01-01

    A micropropagation system has been established for the regeneration of superior trees of Ulmus americana L., the American elm. The development of a reliable regeneration system is also required as a prelude to genetic transformation of selected genotypes. The effects of explant source, media formulations, and plant growth regulator concentrations on...

  6. Clitocybe tabescens associated with decline and death of Chinese elm and water oak

    Treesearch

    T. H. Filer; F. I. McCracken

    1969-01-01

    In 1964, decline symptoms were found on 48 Chinese elms (Ulmus parvifolia) and 2 water oaks (Quercus nigra) in Washington County, Mississippi. Some of their foliage was yellowish, and small lateral branches were dying in parts of the crowns. Large branches later died and the entire crowns were infected.

  7. Statistical correlations between GLC assay and smaller European elm bark beetle bioassay

    Treesearch

    Jack H. Barger; Roy A. Cuthbert; Donald G. Seegrist

    1973-01-01

    American elm trees, Ulmus americana L., were sprayed with methoxychlor by helicopter or mist blower, and twig crotches were collected from sprayed trees for bioassay of Scolytus multistriatus (Marsham) and GLC assay. Correlations established between the 2 assays were dependent on method of application and amount of methoxychlor...

  8. ELM suppression in high-purity DIII-D helium plasmas

    NASA Astrophysics Data System (ADS)

    Evans, T. E.; Gohil, P.; Groebner, R. J.; Osborne, T. H.; Loarte, A.; Unterberg, E.; Grierson, B.; Fenstermacher, M.

    2015-11-01

    ELM suppression in He plasmas with D core concentrations of less than 20 % have been obtained in ECR heated, ITER Similar Shaped plasmas with low pedestal toroidal rotation (vϕ < 10 km/s). Here, n=3 RMP fields are used to suppress large type-I ELMs at power levels marginally above the PL-H threshold (PECRH=2.9 MW). ELM suppression in He plasmas has also been obtained using balanced co- and counter-Ip injected D neutral beams, with PNBI=1.7 MW which is near the PL-H threshold, resulting in vϕ ~ 0. The electron perpendicular rotation frequency during ELM suppression does not cross zero, assuming no uncertainty in the measurement, but remains slightly negative, with an average frequency of -5 krad/s, between 0.80 and 0.94 in normalized poloidal flux. This suggests that magnetic island screening is weak or nonexistent from the top of the H-mode pedestal inward to surfaces relatively deep in the core plasma. Work supported by the U.S. DOE, Office of Science, under DE-FC02-04ER54698, DE-AC05-00OR22725, DE-AC02-09CH11466, DE-AC52-07NA27344.

  9. Validation of BOUT + + ELM simulation by Comparison with ECEI Measurements in the KSTAR tokamak

    NASA Astrophysics Data System (ADS)

    Kim, Minwoo; Lee, Jaehyun; Choi, Minjun; Yun, Gunsu; Xu, X. Q.; Lee, Woochang; Park, Hyeon; Domier, C. W.; Luhmann, N. C., Jr.; Kstar Team

    2013-10-01

    Details of ELM dynamics has been measured in 2D using an electron cyclotron emission imaging (ECEI) diagnostic in the KSTAR tokamak. The observed ELM dynamics show complex evolution stages including linear growth, saturation, changes in mode number and rotation velocity, and localized crash. We studied the mode structure of the observed ELMs in the linear growth phase using 3-field BOUT + + simulations. The toroidal mode number (n) of ELMs, which was experimentally determined by an array of toroidal Mirnov coils, was fixed in the simulation. On the other hand, the pressure profile was adjusted to make the linear growth rate finite at the given n number. For direct comparison with the observed images, the simulation results were converted to synthetic ECEI images by taking into account instrumental broadening, intrinsic ECE broadening in the pedestal region, and system noises. The synthetic images were qualitatively well matched with the observations. As a next step, a simulation study in linear phase is planned for a self-consistent equilibrium including bootstrap current. Work supported by NRF Korea under contract no. 2013035905 and US DoE under contract no. DE-FG-02-99ER54531.

  10. A Possible Connection of Plasma Response to RMP ELM Suppression in DIII-D

    NASA Astrophysics Data System (ADS)

    Wingen, A.; Shafer, M. W.; Unterberg, E. A.; Hillis, D. L.; Ferraro, N. M.; Evans, T. E.; Snyder, P. B.

    2013-10-01

    A hypothesis of a possible relation between the so-called kink-response, a flux surface oscillation which is driven by amplification of non-resonant components of the resonant magnetic perturbation (RMP) spectrum, and the re-appearance of edge localized modes (ELMs) in the presence of RMPs is presented. Several DIII-D discharges with different responses show that those with stronger kink-response are closer to the peeling-ballooning stability limit and eventually cross into the unstable region, causing ELMs to re-appear. Simulations of the magnetic topology for all cases are compared. The topology consists of a kinetic equilibrium reconstruction, the RMP fields and a linear plasma response, calculated by resistive, 2-fluid MHD. It is found that the kink response is correlated to the edge current density while screening/amplification of resonant field components is related to flows. A transition from a tearing dominated edge to a kink dominated edge is demonstrated. A kink dominated discharge with intermittent ELMs is found to be marginally unstable in an ELITE simulation while ELM suppressed, tearing dominated discharges are inside the stability limit. Work supported by the US Department of Energy under DE-AC05-00OR22725, DE-FC02-04ER54698, and DE-FG02-95ER54309.

  11. Response of the european elm bark beetle,Scolytus multistriatus, to host bacterial isolates.

    PubMed

    French, J R; Robinson, P J; Minko, G; Pahl, P J

    1984-07-01

    The response of the European elm bark beetle,Scolytus multistriatus, to host bacterial isolates was studied qualitatively under field conditions. Initial experiments indicated that such isolates were attractive to in-flight beetles. These isolates, identified asBacillus subtilis (five strains),B. pumilus, andEnterobacter cloacae, were grown on nutrient agar in glass vials and attached to sticky traps in elm woods. Although beetles were caught on the bacterial isolate-baited traps, the catches were variable, inconsistent, and often contradictory from one experiment to another. High numbers ofS. multistriatus were caught on traps baited with three strains ofB. subtilis, but in addition to thesubtilis strains, there were also aerial contaminants in the treatments, namelyE. aerogenes, Corynebacterium sp., andFlavobacterium sp. Also, relatively high catches were recorded on nutrient agar controls. When elm wood-bark plugs, sterilized (by gamma irradiation) and unsterilized, were placed in vials with the host bacterial isolates, the presence or absence of fresh elm, gamma irradiated or not, had no noticeable effect on beetle attractancy.

  12. Electron temperature fluctuations changes associated with ELM suppression by RMP in DIII-D

    NASA Astrophysics Data System (ADS)

    Sung, C.; Wang, G.; Rhodes, T.; Peebles, W.

    2015-11-01

    New results in this presentation show an increase in broadband electron temperature fluctuations (T~e) during ELM suppression by resonant magnetic perturbations (RMP). This measurement is obtained via correlation ECE (CECE) near the top of the pedestal (ρ ~ 0.9 - 0.96). This T~e increase is significant, (>40%), and occurs after the ELM suppression but not between ELMS. This may imply an increase in thermal transport facilitated by the increased T~e levels. Considering that the changes in gradient scale length during ELMs with RMP are complicated, it is possible that the mechanism responsible for changing T~e is different compared to previously observed changes in ñe [G. R. McKee et al NF 2013]. This possibility, and the nature of the T~e , will be studied through profile analysis and linear gyrokinetic analysis using TGLF [J. E. Kinsey et al PoP 2008]. In addition, the relation between the T~e and an observed low frequency coherent mode will be investigated. Work supported by the US DOE under DE-FG02-08ER54984 and DE-FC02-04ER54698.

  13. An elm EST database for identifying leaf beetle egg-induced defense genes

    PubMed Central

    2012-01-01

    Background Plants can defend themselves against herbivorous insects prior to the onset of larval feeding by responding to the eggs laid on their leaves. In the European field elm (Ulmus minor), egg laying by the elm leaf beetle ( Xanthogaleruca luteola) activates the emission of volatiles that attract specialised egg parasitoids, which in turn kill the eggs. Little is known about the transcriptional changes that insect eggs trigger in plants and how such indirect defense mechanisms are orchestrated in the context of other biological processes. Results Here we present the first large scale study of egg-induced changes in the transcriptional profile of a tree. Five cDNA libraries were generated from leaves of (i) untreated control elms, and elms treated with (ii) egg laying and feeding by elm leaf beetles, (iii) feeding, (iv) artificial transfer of egg clutches, and (v) methyl jasmonate. A total of 361,196 ESTs expressed sequence tags (ESTs) were identified which clustered into 52,823 unique transcripts (Unitrans) and were stored in a database with a public web interface. Among the analyzed Unitrans, 73% could be annotated by homology to known genes in the UniProt (Plant) database, particularly to those from Vitis, Ricinus, Populus and Arabidopsis. Comparative in silico analysis among the different treatments revealed differences in Gene Ontology term abundances. Defense- and stress-related gene transcripts were present in high abundance in leaves after herbivore egg laying, but transcripts involved in photosynthesis showed decreased abundance. Many pathogen-related genes and genes involved in phytohormone signaling were expressed, indicative of jasmonic acid biosynthesis and activation of jasmonic acid responsive genes. Cross-comparisons between different libraries based on expression profiles allowed the identification of genes with a potential relevance in egg-induced defenses, as well as other biological processes, including signal transduction, transport and

  14. An Efficient Leave-One-Out Cross-Validation-Based Extreme Learning Machine (ELOO-ELM) With Minimal User Intervention.

    PubMed

    Shao, Zhifei; Er, Meng Joo; Wang, Ning

    2016-08-01

    It is well known that the architecture of the extreme learning machine (ELM) significantly affects its performance and how to determine a suitable set of hidden neurons is recognized as a key issue to some extent. The leave-one-out cross-validation (LOO-CV) is usually used to select a model with good generalization performance among potential candidates. The primary reason for using the LOO-CV is that it is unbiased and reliable as long as similar distribution exists in the training and testing data. However, the LOO-CV has rarely been implemented in practice because of its notorious slow execution speed. In this paper, an efficient LOO-CV formula and an efficient LOO-CV-based ELM (ELOO-ELM) algorithm are proposed. The proposed ELOO-ELM algorithm can achieve fast learning speed similar to the original ELM without compromising the reliability feature of the LOO-CV. Furthermore, minimal user intervention is required for the ELOO-ELM, thus it can be easily adopted by nonexperts and implemented in automation processes. Experimentation studies on benchmark datasets demonstrate that the proposed ELOO-ELM algorithm can achieve good generalization with limited user intervention while retaining the efficiency feature.

  15. Effect of Aspect Ratio on H-mode and ELM Characteristics

    NASA Astrophysics Data System (ADS)

    Thome, K. E.; Bodner, G. M.; Bongard, M. W.; Burke, M. G.; Fonck, R. J.; Kriete, D. M.

    2015-11-01

    The H-mode confinement regime is achieved at near-unity aspect ratio (A < 1 . 2) in the Pegasus Toroidal Experiment via high-field-side fueling and low edge recycling. Ohmic H-mode is attained in both limited and diverted magnetic topologies. This regime is characterized by: reduced Dα emissions; increased core rotation; increased central heating; formation of edge current and pressure pedestals; and measured energy confinement consistent with the ITER98pb(y,2) scaling. The H-mode power threshold, PLH , behaves quite differently at low- A when compared with high- A operations. PLH /PLH_ITPA 08 increases sharply as A is lowered and no difference in PLH for limited and diverted plasmas is observed at A ~ 1 . 2 . No minimum in PLH with density is observed. Some of these results are consistent with the FM3 model for the L-H transition. Two classes of ELMs have been observed. Small, Type III-like ELMs are present at low input power and have n <= 4 . At POH >>PLH , they transition to large, Type-I-like ELMs with intermediate 5 < n < 15 . The Type III ELM magnetic structures behave opposite that of high- A plasmas, with n much higher, presumably due to the naturally higher J / B peeling mode drive at low- A . Long-sought measurements of the Jedge (R , t) pedestal collapse during an ELM event show a complex, multimodal pedestal collapse and the subsequent ejection of a current-carrying filament. Work supported by US DOE grant DE-FG02-96ER54375.

  16. Tree and stand transpiration in a Midwestern bur oak savanna after elm encroachment and restoration thinning

    USGS Publications Warehouse

    Asbjornsen, H.; Tomer, M.D.; Gomez-Cardenas, M.; Brudvig, L.A.; Greenan, C.M.; Schilling, K.

    2007-01-01

    Oak savannas, once common in the Midwest, are now isolated remnants within agricultural landscapes. Savanna remnants are frequently encroached by invasive trees to become woodlands. Thinning and prescribed burning can restore savanna structure, but the ecohydrological effects of managing these remnants are poorly understood. In this study, we measured sap flow (Js) to quantify transpiration in an Iowa bur oak (Quercus macrocarpa) savanna woodland encroached by elms (Ulmus americana), and in an adjacent restored savanna after thinning to remove elms, during summer 2004. Savanna oaks had greater mean daily Js (35.9 L dm-2 day-1) than woodland oaks (20.7 L dm-2 day-1) and elms (12.4 L dm-2 day-1). The response of Js to vapor pressure deficit (D) was unexpectedly weak, although oaks in both stands showed negative correlation between daily Js and D for D > 0.4 kPa. An earlier daily peak in Js in the elm trees showed a possible advantage for water uptake. As anticipated, the woodland's stand transpiration was greater (1.23 mm day-1) than the savanna's (0.35 mm day-1), yet the savanna achieved 30% of the woodland's transpiration with only 11% of its sapwood area. The difference in transpiration influenced water table depths, which were 2 m in the savanna and 6.5 m in the woodland. Regionally, row-crop agriculture has increased groundwater recharge and raised water tables, providing surplus water that perhaps facilitated elm encroachment. This has implications for restoration of savanna remnants. If achieving a savanna ecohydrology is an aim of restoration, then restoration strategies may require buffers, or targeting of large or hydrologically isolated remnants. ?? 2007.

  17. Spatial Distribution and Site-Specific Spraying of Main Sucking Pests of Elm Trees.

    PubMed

    Karimzadeh, R; Iranipour, S

    2016-11-09

    Elm trees are important landscape trees and sucking insects weaken the elm trees and produce large amounts of honeydew. The main objectives of this study were to identify main honeydew-producing pests of elm trees and do site-specific spraying against these pests. To map the spatial distribution of the sucking pests in the large scale, the study area was divided into 40 × 40 m grids and one tree was chosen randomly from each grid (a total of 55 trees). These trees were sampled twice a year in 2011 and 2012. Each sample was a 30-cm branch terminal. Eight samples were taken from each tree in four cardinal directions and two canopy levels. The number of sucking insects and leaves of each sample were counted and recorded. Spatial analysis of the data was carried out using geostatistics. Kriging was used for producing prediction maps. Insecticide application was restricted to the regions with populations higher than threshold. To identify within-tree distribution of the honeydew-producing pests, six and four elm trees were chosen in 2011 and 2012 respectively, and sampled weekly. These trees were sampled as described previously. European elm scale (EES), Gossyparia spuria (Modeer) and two species of aphids were the dominant honeydew-producing pests. The results revealed that the effects of direction, canopy level and their interactions on insect populations were not statistically significant (P < 0.05). Site-specific spraying decreased the amount of insecticides used by ca. 20%, while satisfactory control of the sucking pests and honeydew excretion was obtained. Considering the environmental and economic benefits of site-specific spraying, it is worth doing more complementary works in this area.

  18. Impact of Te and ne on edge current density profiles in ELM mitigated regimes on ASDEX Upgrade

    NASA Astrophysics Data System (ADS)

    Dunne, M. G.; Rathgeber, S.; Burckhart, A.; Fischer, R.; Giannone, L.; McCarthy, P. J.; Schneider, P. A.; Wolfrum, E.; the ASDEX Upgrade Team

    2015-01-01

    ELM resolved edge current density profiles are reconstructed using the CLISTE equilibrium code. As input, highly spatially and temporally resolved edge electron temperature and density profiles are used in addition to data from the extensive set of external poloidal field measurements available at ASDEX Upgrade, flux loop difference measurements, and current measurements in the scrape-off layer. Both the local and flux surface averaged current density profiles are analysed for several ELM mitigation regimes. The focus throughout is on the impact of altered temperature and density profiles on the current density. In particular, many ELM mitigation regimes rely on operation at high density. Two reference plasmas with type-I ELMs are analysed, one with a deuterium gas puff and one without, in order to provide a reference for the behaviour in type-II ELMy regimes and high density ELM mitigation with external magnetic perturbations at ASDEX Upgrade. For type-II ELMs it is found that while a similar pedestal top pressure is sustained at the higher density, the temperature gradient decreases in the pedestal. This results in lower local and flux surface averaged current densities in these phases, which reduces the drive for the peeling mode. No significant differences between the current density measured in the type-I phase and ELM mitigated phase is seen when external perturbations are applied, though the pedestal top density was increased. Finally, ELMs during the nitrogen seeded phase of a high performance discharge are analysed and compared to ELMs in the reference phase. An increased pedestal pressure gradient, which is the source of confinement improvement in impurity seeded discharges, causes a local current density increase. However, the increased Zeff in the pedestal acts to reduce the flux surface averaged current density. This dichotomy, which is not observed in other mitigation regimes, could act to stabilize both the ballooning mode and the peeling mode at the

  19. [Effects of aboveground and belowground competition between grass and tree on elm seedlings growth in Horqin Sandy Land].

    PubMed

    Tang, Yi; Jiang, De-ming; Chen, Zhuo; Toshio, Oshida

    2011-08-01

    Elm sparse woodland steppe plays an important role in vegetation restoration and landscape protection in Horqin Sandy Land. In this paper, a two-factor and two-level field experiment was conducted to explore the effects of aboveground and belowground competition between grass and tree on the growth of elm seedlings in the Sandy Land. Five aspects were considered, i.e., seedling biomass, belowground biomass/aboveground biomass, stem height, ratio of root to stem, and leaf number. For the one-year-old elm seedlings, their biomass showed a trend of no competition > aboveground competition > full competition > belowground competition, belowground biomass / aboveground biomass showed a trend of belowground competition > full competition > no competition > aboveground competition, stem height showed a trend of aboveground competition > no competition > full competition > belowground competition, root/stem ratio showed a trend of belowground competition > full competition > no competition > aboveground competition, and leaf number showed a trend of aboveground competition > no competition > belowground competition > full competition. Belowground competition had significant effects on the growth of one-year-old elm seedlings, while aboveground competition did not have. Neither belowground competition nor aboveground competition had significant effects on the growth of two-year-old elm seedlings. It was suggested that in Horqin Sandy Land, grass affected the growth of elm seedlings mainly via below-ground competition, but the belowground competition didn' t affect the resource allocation of elm seedlings. With the age increase of elm seedlings, the effects of grass competition on the growth of elm seedlings became weaker.

  20. Recent progress in understanding the processes underlying the triggering of and energy loss associated with type I ELMs

    NASA Astrophysics Data System (ADS)

    Kirk, A.; Dunai, D.; Dunne, M.; Huijsmans, G.; Pamela, S.; Becoulet, M.; Harrison, J. R.; Hillesheim, J.; Roach, C.; Saarelma, S.

    2014-11-01

    The type I ELMy H-mode is the baseline operating scenario for ITER. While it is known that the type I edge-localized mode (ELM) ultimately results from the peeling-ballooning instability, there is growing experimental evidence that a mode grows up before the ELM crash that may modify the edge plasma, which then leads to the ELM event due to the peeling-ballooning mode. The triggered mode results in the release of a large number of particles and energy from the core plasma but the precise mechanism by which these losses occur is still not fully understood and hence makes predictions for future devices uncertain. Recent progress in understanding the processes that trigger type I ELMs and the size of the resultant energy loss are reviewed and compared to experimental data and ideas for further development are discussed.

  1. Progress on the application of ELM control schemes to ITER scenarios from the non-active phase to DT operation

    NASA Astrophysics Data System (ADS)

    Loarte, A.; Huijsmans, G.; Futatani, S.; Baylor, L. R.; Evans, T. E.; Orlov, D. M.; Schmitz, O.; Becoulet, M.; Cahyna, P.; Gribov, Y.; Kavin, A.; Sashala Naik, A.; Campbell, D. J.; Casper, T.; Daly, E.; Frerichs, H.; Kischner, A.; Laengner, R.; Lisgo, S.; Pitts, R. A.; Saibene, G.; Wingen, A.

    2014-03-01

    Progress in the definition of the requirements for edge localized mode (ELM) control and the application of ELM control methods both for high fusion performance DT operation and non-active low-current operation in ITER is described. Evaluation of the power fluxes for low plasma current H-modes in ITER shows that uncontrolled ELMs will not lead to damage to the tungsten (W) divertor target, unlike for high-current H-modes in which divertor damage by uncontrolled ELMs is expected. Despite the lack of divertor damage at lower currents, ELM control is found to be required in ITER under these conditions to prevent an excessive contamination of the plasma by W, which could eventually lead to an increased disruptivity. Modelling with the non-linear MHD code JOREK of the physics processes determining the flow of energy from the confined plasma onto the plasma-facing components during ELMs at the ITER scale shows that the relative contribution of conductive and convective losses is intrinsically linked to the magnitude of the ELM energy loss. Modelling of the triggering of ELMs by pellet injection for DIII-D and ITER has identified the minimum pellet size required to trigger ELMs and, from this, the required fuel throughput for the application of this technique to ITER is evaluated and shown to be compatible with the installed fuelling and tritium re-processing capabilities in ITER. The evaluation of the capabilities of the ELM control coil system in ITER for ELM suppression is carried out (in the vacuum approximation) and found to have a factor of ˜2 margin in terms of coil current to achieve its design criterion, although such a margin could be substantially reduced when plasma shielding effects are taken into account. The consequences for the spatial distribution of the power fluxes at the divertor of ELM control by three-dimensional (3D) fields are evaluated and found to lead to substantial toroidal asymmetries in zones of the divertor target away from the separatrix

  2. ELM - A SIMPLE TOOL FOR THERMAL-HYDRAULIC ANALYSIS OF SOLID-CORE NUCLEAR ROCKET FUEL ELEMENTS

    NASA Technical Reports Server (NTRS)

    Walton, J. T.

    1994-01-01

    ELM is a simple computational tool for modeling the steady-state thermal-hydraulics of propellant flow through fuel element coolant channels in nuclear thermal rockets. Written for the nuclear propulsion project of the Space Exploration Initiative, ELM evaluates the various heat transfer coefficient and friction factor correlations available for turbulent pipe flow with heat addition. In the past, these correlations were found in different reactor analysis codes, but now comparisons are possible within one program. The logic of ELM is based on the one-dimensional conservation of energy in combination with Newton's Law of Cooling to determine the bulk flow temperature and the wall temperature across a control volume. Since the control volume is an incremental length of tube, the corresponding pressure drop is determined by application of the Law of Conservation of Momentum. The size, speed, and accuracy of ELM make it a simple tool for use in fuel element parametric studies. ELM is a machine independent program written in FORTRAN 77. It has been successfully compiled on an IBM PC compatible running MS-DOS using Lahey FORTRAN 77, a DEC VAX series computer running VMS, and a Sun4 series computer running SunOS UNIX. ELM requires 565K of RAM under SunOS 4.1, 360K of RAM under VMS 5.4, and 406K of RAM under MS-DOS. Because this program is machine independent, no executable is provided on the distribution media. The standard distribution medium for ELM is one 5.25 inch 360K MS-DOS format diskette. ELM was developed in 1991. DEC, VAX, and VMS are trademarks of Digital Equipment Corporation. Sun4 and SunOS are trademarks of Sun Microsystems, Inc. IBM PC is a registered trademark of International Business Machines. MS-DOS is a registered trademark of Microsoft Corporation.

  3. ELM - A SIMPLE TOOL FOR THERMAL-HYDRAULIC ANALYSIS OF SOLID-CORE NUCLEAR ROCKET FUEL ELEMENTS

    NASA Technical Reports Server (NTRS)

    Walton, J. T.

    1994-01-01

    ELM is a simple computational tool for modeling the steady-state thermal-hydraulics of propellant flow through fuel element coolant channels in nuclear thermal rockets. Written for the nuclear propulsion project of the Space Exploration Initiative, ELM evaluates the various heat transfer coefficient and friction factor correlations available for turbulent pipe flow with heat addition. In the past, these correlations were found in different reactor analysis codes, but now comparisons are possible within one program. The logic of ELM is based on the one-dimensional conservation of energy in combination with Newton's Law of Cooling to determine the bulk flow temperature and the wall temperature across a control volume. Since the control volume is an incremental length of tube, the corresponding pressure drop is determined by application of the Law of Conservation of Momentum. The size, speed, and accuracy of ELM make it a simple tool for use in fuel element parametric studies. ELM is a machine independent program written in FORTRAN 77. It has been successfully compiled on an IBM PC compatible running MS-DOS using Lahey FORTRAN 77, a DEC VAX series computer running VMS, and a Sun4 series computer running SunOS UNIX. ELM requires 565K of RAM under SunOS 4.1, 360K of RAM under VMS 5.4, and 406K of RAM under MS-DOS. Because this program is machine independent, no executable is provided on the distribution media. The standard distribution medium for ELM is one 5.25 inch 360K MS-DOS format diskette. ELM was developed in 1991. DEC, VAX, and VMS are trademarks of Digital Equipment Corporation. Sun4 and SunOS are trademarks of Sun Microsystems, Inc. IBM PC is a registered trademark of International Business Machines. MS-DOS is a registered trademark of Microsoft Corporation.

  4. Scrape-off layer ion temperature measurements at the divertor target during type III and type I ELMs in MAST measured by RFEA

    NASA Astrophysics Data System (ADS)

    Elmore, S.; Allan, S. Y.; Fishpool, G.; Kirk, A.; Thornton, A. J.; Walkden, N. R.; Harrison, J. R.; the MAST Team

    2016-06-01

    In future nuclear fusion reactors high heat load events, such as edge-localised modes (ELMs), can potentially damage divertor materials and release impurities into the main plasma, limiting plasma performance. The most difficult to handle are type I ELMs since they carry the largest fraction of energy from the plasma and therefore deposit the largest heat flux at the target and on first wall materials. Knowing the temperature of the ions released from ELM events is important since it determines the potential sputtering they would cause from plasma facing materials. To make measurements of T i by retarding field energy analyser (RFEA) during type I ELMs a new operational technique has been used to allow faster measurements to be made; this is called the fast swept technique (FST). The FST method allows measurements to be made within the time of the ELM event which has previously not been possible with T i measurements. This new technique has been validated by comparing it with a slower average measurement previously used to make ion temperature measurements of ELMs. Presented here are the first T i measurements during Type I ELMs made at a tokamak divertor. Temperatures as high as 20 eV are measured more than 15 cm from the peak heat flux of an ELM, in a region where no inter-ELM current is measured by the RFEA; showing that ELM events cause hot ions to reach the divertor target far into the scrape off layer. Fast camera imaging has been used to investigate the type of ELM filaments that have been measured by the divertor RFEA. It is postulated that most of the ion temperatures measured in type I ELMs are from secondary ELM filaments which have not been previously identified in MAST plasmas.

  5. 77 FR 19967 - Safety Zone, Port of Dutch Harbor; Dutch Harbor, AK

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-03

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone, Port of Dutch Harbor; Dutch Harbor, AK... temporary safety zones in the Port of Dutch Harbor, Alaska, and adjacent U.S. territorial sea from 12:01 a.m... high volume of vessel traffic in the Port of Dutch Harbor, Alaska, and the adjacent territorial sea due...

  6. Dry deposition of sulfur dioxide and nitric acid to oak, elm and pine leaves

    SciTech Connect

    Dash, J.M. )

    1988-01-01

    In this study, the deposition of SO{sub 2} and HNO{sub 3} was measured to three tree species, elm, oak and pine. Earlier work has shown that these three species cover of physical types (smooth oak leaves, rough elm leaves, and needles) and chemical types (acid and alkaline leaves) The total deposition is compared to the deposition measured through the stomata. After deposition, removal by revolatilization or extraction was determined. The data is used to estimate dry deposition fluxes of SO{sub 2} and HNO{sub 3} to forests that can then be combined with wet fluxes to determine total atmospheric inputs. Based on these results, a preliminary estimate is made of the possible detrimental effects to forests from atomspheric inputs.

  7. Fault Diagnosis for Analog Circuits by Using EEMD, Relative Entropy, and ELM

    PubMed Central

    Tian, Shulin

    2016-01-01

    This paper presents a novel fault diagnosis method for analog circuits using ensemble empirical mode decomposition (EEMD), relative entropy, and extreme learning machine (ELM). First, nominal and faulty response waveforms of a circuit are measured, respectively, and then are decomposed into intrinsic mode functions (IMFs) with the EEMD method. Second, through comparing the nominal IMFs with the faulty IMFs, kurtosis and relative entropy are calculated for each IMF. Next, a feature vector is obtained for each faulty circuit. Finally, an ELM classifier is trained with these feature vectors for fault diagnosis. Via validating with two benchmark circuits, results show that the proposed method is applicable for analog fault diagnosis with acceptable levels of accuracy and time cost. PMID:27698663

  8. Target Plate Profiles During ELM Suppression Experiments on DIII-D

    NASA Astrophysics Data System (ADS)

    Watkins, J. G.; Evans, T. E.; Murphy, C. J.; Martin, M. J.; Nelson, A.; Jakubowski, M.; Joseph, I.; Moyer, R. A.; Lasnier, C. J.; Fenstermacher, M. E.

    2007-11-01

    Radial profiles of target plate plasma conditions during ELM suppressed conditions have been measured with the new DIII-D lower divertor Langmuir probe array. ELM suppression was accomplished using n=3 resonant magnetic perturbations [1]. Evidence of the n=3 mode structure of the perturbation can be seen most clearly in the Vf profile on the target plate. The spacing of the multiple peaks in the Vf profile is similar to predictions of the TRIP3D field line integration code. Te values >100 eV and Vf values down to --150 V were measured. We observe resonant behavior of the target plate parameters near the q95 value for maximum magnetic perturbation. Heat flux from the Langmuir probe measurements will be compared with infrared cameras and thermocouples. The resulting sheath power transmission factor profile will be shown. [1] T.E. Evans, et al., Phys. Rev. Lett. 92, 235003 (2004).

  9. Fault Diagnosis for Analog Circuits by Using EEMD, Relative Entropy, and ELM.

    PubMed

    Xiong, Jian; Tian, Shulin; Yang, Chenglin

    2016-01-01

    This paper presents a novel fault diagnosis method for analog circuits using ensemble empirical mode decomposition (EEMD), relative entropy, and extreme learning machine (ELM). First, nominal and faulty response waveforms of a circuit are measured, respectively, and then are decomposed into intrinsic mode functions (IMFs) with the EEMD method. Second, through comparing the nominal IMFs with the faulty IMFs, kurtosis and relative entropy are calculated for each IMF. Next, a feature vector is obtained for each faulty circuit. Finally, an ELM classifier is trained with these feature vectors for fault diagnosis. Via validating with two benchmark circuits, results show that the proposed method is applicable for analog fault diagnosis with acceptable levels of accuracy and time cost.

  10. Stabilizing effect of resistivity towards ELM-free H-mode discharge in lithium-conditioned NSTX

    NASA Astrophysics Data System (ADS)

    Banerjee, Debabrata; Zhu, Ping; Maingi, Rajesh

    2017-07-01

    Linear stability analysis of the national spherical torus experiment (NSTX) Li-conditioned ELM-free H-mode equilibria is carried out in the context of the extended magneto-hydrodynamic (MHD) model in NIMROD. The purpose is to investigate the physical cause behind edge localized mode (ELM) suppression in experiment after the Li-coating of the divertor and the first wall of the NSTX tokamak. Besides ideal MHD modeling, including finite-Larmor radius effect and two-fluid Hall and electron diamagnetic drift contributions, a non-ideal resistivity model is employed, taking into account the increase of Z eff after Li-conditioning in ELM-free H-mode. Unlike an earlier conclusion from an eigenvalue code analysis of these equilibria, NIMROD results find that after reduced recycling from divertor plates, profile modification is necessary but insufficient to explain the mechanism behind complete ELMs suppression in ideal two-fluid MHD. After considering the higher plasma resistivity due to higher Z eff, the complete stabilization could be explained. A thorough analysis of both pre-lithium ELMy and with-lithium ELM-free cases using ideal and non-ideal MHD models is presented, after accurately including a vacuum-like cold halo region in NIMROD to investigate ELMs.

  11. Comparison study between the observed ELM dynamics in the KSTAR H-mode and simulation results from BOUT++

    NASA Astrophysics Data System (ADS)

    Kim, Minwoo; Xu, Xueqiao; Yun, Gunsu S.; Lee, Jaehyun; Park, Hyeon K.

    2012-10-01

    The BOUT++ simulations [1] of edge localized modes (ELMs) have been quantitatively compared with high resolution 2D images of ELMs observed in typical KSTAR H-mode plasmas through an electron cyclotron emission imaging (ECEI) system [2]. The poloidal structure of the most unstable mode predicted by the linear 3-field simulation qualitatively matches with the observed ELM structure. As the next step, simulation studies for the nonlinear aspects of the ELM dynamics are planned; in particular, the transient mode structure change prior to the ELM crash [2] will be investigated. In addition, the parametric dependence of the observed ELM suppression/mitigation process during resonant magnetic perturbation (RMP) [2, 3] and supersonic molecular beam injection (SMBI) experiments will be studied using 5-field BOUT++ simulation.[4pt] [1] X.Q. Xu et al., PRL, 105 (2010).[0pt] [2] G.S. Yun et al., Phys. Plasmas, 19 (2012).[0pt] [3] Y.M. Jeon et al., accepted for publication in PRL.

  12. Stabilizing effect of resistivity towards ELM-free H-mode discharge in lithium-conditioned NSTX

    DOE PAGES

    Banerjee, Debabrata; Zhu, Ping; Maingi, Rajesh

    2017-05-12

    Linear stability analysis of the national spherical torus experiment (NSTX) Li-conditioned ELM-free H-mode equilibria is carried out in the context of the extended magneto-hydrodynamic (MHD) model in NIMROD. Our purpose is to investigate the physical cause behind edge localized mode (ELM) suppression in experiment after the Li-coating of the divertor and the first wall of the NSTX tokamak. Besides ideal MHD modeling, including finite-Larmor radius effect and two-fluid Hall and electron diamagnetic drift contributions, a non-ideal resistivity model is employed, taking into account the increase of Z eff after Li-conditioning in ELM-free H-mode. And unlike an earlier conclusion from anmore » eigenvalue code analysis of these equilibria, NIMROD results find that after reduced recycling from divertor plates, profile modification is necessary but insufficient to explain the mechanism behind complete ELMs suppression in ideal two-fluid MHD. After considering the higher plasma resistivity due to higher Z eff, the complete stabilization could be explained. Furthermore, a thorough analysis of both pre-lithium ELMy and with-lithium ELM-free cases using ideal and non-ideal MHD models is presented, after accurately including a vacuum-like cold halo region in NIMROD to investigate ELMs.« less

  13. Comparative ELM study between the observation by ECEI and linear/nonlinear simulation in the KSTAR plasmas

    NASA Astrophysics Data System (ADS)

    Kim, Minwoo; Park, Hyeon K.; Yun, Gunsu; Lee, Jaehyun; Lee, Jieun; Lee, Woochang; Jardin, Stephen; Xu, X. Q.; Kstar Team

    2015-11-01

    The modeling of the Edge-localized-mode (ELM) should be rigorously pursued for reliable and robust ELM control for steady-state long-pulse H-mode operation in ITER as well as DEMO. In the KSTAR discharge #7328, a linear stability of the ELMs is investigated using M3D-C1 and BOUT + + codes. This is achieved by linear simulation for the n = 8 mode structure of the ELM observed by the KSTAR electron cyclotron emission imaging (ECEI) systems. In the process of analysis, variations due to the plasma equilibrium profiles and transport coefficients on the ELM growth rate are investigated and simulation results with the two codes are compared. The numerical simulations are extended to nonlinear phase of the ELM dynamics, which includes saturation and crash of the modes. Preliminary results of the nonlinear simulations are compared with the measured images especially from the saturation to the crash. This work is supported by NRF of Korea under contract no. NRF-2014M1A7A1A03029865, US DoE by LLNL under contract DE-AC52-07NA27344 and US DoE by PPPL under contract DE-AC02-09CH11466.

  14. Neonicotinoid Insecticide Imidacloprid Causes Outbreaks of Spider Mites on Elm Trees in Urban Landscapes

    PubMed Central

    Szczepaniec, Adrianna; Creary, Scott F.; Laskowski, Kate L.; Nyrop, Jan P.; Raupp, Michael J.

    2011-01-01

    Background Attempts to eradicate alien arthropods often require pesticide applications. An effort to remove an alien beetle from Central Park in New York City, USA, resulted in widespread treatments of trees with the neonicotinoid insecticide imidacloprid. Imidacloprid's systemic activity and mode of entry via roots or trunk injections reduce risk of environmental contamination and limit exposure of non-target organisms to pesticide residues. However, unexpected outbreaks of a formerly innocuous herbivore, Tetranychus schoenei (Acari: Tetranychidae), followed imidacloprid applications to elms in Central Park. This undesirable outcome necessitated an assessment of imidacloprid's impact on communities of arthropods, its effects on predators, and enhancement of the performance of T. schoenei. Methodology/Principal Findings By sampling arthropods in elm canopies over three years in two locations, we document changes in the structure of communities following applications of imidacloprid. Differences in community structure were mostly attributable to increases in the abundance of T. schoenei on elms treated with imidacloprid. In laboratory experiments, predators of T. schoenei were poisoned through ingestion of prey exposed to imidacloprid. Imidacloprid's proclivity to elevate fecundity of T. schoenei also contributed to their elevated densities on treated elms. Conclusions/Significance This is the first study to report the effects of pesticide applications on the arthropod communities in urban landscapes and demonstrate that imidacloprid increases spider mite fecundity through a plant-mediated mechanism. Laboratory experiments provide evidence that imidacloprid debilitates insect predators of spider mites suggesting that relaxation of top-down regulation combined with enhanced reproduction promoted a non-target herbivore to pest status. With global commerce accelerating the incidence of arthropod invasions, prophylactic applications of pesticides play a major role in

  15. External kink modes as a model for MHD activity associated with ELMs

    SciTech Connect

    Manickam, J.

    1992-01-01

    Tokamak plasmas in the high confinement mode of operation are known to exhibit edge localized activity referred to as ELMs. A model is proposed for the underlying cause in terms of the external kink mode. The build up of the current density near the plasma edge is shown to decrease the shear in the safety-factor, q, profile and lead to destabilization of the kink mode. The role of the plasma geometry and equilibrium profiles is discussed.

  16. PROGRESS IN THE PEELING-BALLOONING MODEL OF ELMS: TOROIDAL ROTATION AND 3D NONLINEAR DYNAMICS

    SciTech Connect

    SNYDER,P.B; WILSON,H.R; XU,X.Q; WEBSTER,A.J

    2004-06-01

    Understanding the physics of the H-Mode pedestal and edge localized modes (ELMs) is very important to next-step fusion devices for two primary reasons: (1) The pressure at the top of the edge barrier (''pedestal height'') strongly impacts global confinement and fusion performance, and (2) large ELMs lead to localized transient heat loads on material surfaces that may constrain component lifetimes. The development of the peeling-ballooning model has shed light on these issues by positing a mechanism for ELM onset and constraints on the pedestal height. The mechanism involves instability of ideal coupled ''peeling-ballooning'' modes driven by the sharp pressure gradient and consequent large bootstrap current in the H-mode edge. It was first investigated in the local, high-n limit [1], and later quantified for non-local, finite-n modes in general toroidal geometry [2,3]. Important aspects are that a range of wavelengths may potentially be unstable, with intermediate n's (n {approx} 3-30) generally limiting in high performance regimes, and that stability bounds are strongly sensitive to shape [Fig l(a)], and to collisionality (i.e. temperature and density) [4] through the bootstrap current. The development of efficient MHD stability codes such as ELITE [3,2] and MISHKA [5] has allowed detailed quantification of peeling-ballooning stability bounds (e.g. [6]) and extensive and largely successful comparisons with observation (e.g. [2,6-9]). These previous calculations are ideal, static, and linear. Here we extend this work to incorporate the impact of sheared toroidal rotation, and the non-ideal, nonlinear dynamics which must be studied to quantify ELM size and heat deposition on material surfaces.

  17. Treatment and prevention of coronary heart disease by lowering serum cholesterol levels; from the pioneer work of C.D. de Langen to the third "Dutch Consensus on Cholesterol".

    PubMed

    Jukema, J W; Simoons, M L

    1999-06-01

    In the beginning of this century a possible relation was observed between cholesterol-rich foods, blood cholesterol levels and atherosclerosis by "pioneers" in this field as Anitschkow and De Langen. In the second half of this century a definite link was established between serum cholesterol levels and development of coronary heart disease (CHD). In angiographic studies it has recently been shown that a decrease in total cholesterol as well as in low-density lipoprotein cholesterol level results in a retardation of the progression of vascular disease. Furthermore, clinical event intervention trials demonstrated that therapy with cholesterol synthesis inhibitors reduces not only cardiovascular and total mortality, but also other manifestations of CHD. These recent results prompted to revise, for the second time, the Dutch consensus text for lipid lowering therapy, with the following conclusions. Hypercholesterolaemia is treated with a low-saturated fat diet and normalisation of weight. For individuals, this might result in a reduction of the risk for myocardial infarction or death and for the population in a decrease of the mean serum cholesterol concentration and a reduction of the incidence of CHD. The indication for drug therapy is founded on the expected effectiveness to reduce the incidence of (new manifestations of) CHD, which is related to the level of the absolute risk of vascular disease. Treatment with cholesterol synthesis inhibitors must be considered in (a) patients with familial hypercholesterolaemia; (b) all patients with a history of myocardial infarction or other symptomatic vascular disease with a total cholesterol concentration above 5.0 mmol/l and a life expectancy of at least five years; (c) persons without known vascular disease with a combination of diabetes mellitus, hypertension, hypercholesterolaemia, cigarette smoking and high risk for development of CHD, rising from 25% per 10 years at the age of 40 years to 35-40% per 10 years at the age

  18. Characteristics of the TFTR limiter H-mode: The transition, ELMs, transport and confinement

    SciTech Connect

    Bush, C.E. ); Bretz, N.; Nazikian, R.; Stratton, B.C.; Synakowski, E.; Taylor, G. Budny, R.; Ramsey, A.T.; Scott, S.D.; Bell, M.; Bell, R.; Biglari, H.; Bitter, M.; Darrow, D.S.; Efthimion, P.; Fredrickson, E.D.; Hill, K.; Hsuan, H.; Kilpatrick, S.; McGuire, K.M.; Manos, D.; Mansfield, D.; Medley, S.S.; Mueller, D.; Park, H.; Paul, S.; Sabbagh, S.; Schivell, J.; Thompson, M.; Town

    1992-11-01

    H-Modes obtained through transitions from the supershot regime have been studied on TFTR. The characteristics of these H-modes are similar to those found on other tokamaks with one main exception, the density prof:des can be highly peaked. In the best cases the enhanced confinement in the core of the initial supershot is retained in the H-mode phase, while the confinement in a broad edge region is enhanced. Thus in TFTR, all of the important physics of H-modes such as transitions, enhanced edge confinement, ELMs and other phenomena are studied in a large circular limiter tokamak with the added feature of centrally peaked density profiles and the advantage of an extensive set of diagnostics. The threshold power for the transition is found to be a linear function of plasma current. Transitions and ELMs are affected by the mix of co-and counter-neutral beam injection (NBI) and by perturbations introduced by pellet injection, gas puffing, and current ramping before and during NBI. Fluctuations near both transition and ELM events have been characterized. High frequency magnetic fluctuations in the range [ge] 100--250 kHz usually decrease during the transition. Microwave scattering spectra of density fluctuations in the plasma edge show a feature at high frequency during the H-mode, which is not observed in the plasma core and which is consistent with an edge poloidal rotation velocity, V[sub [theta

  19. Toroidal drift modes in tokamaks: a new model for small ELMs

    NASA Astrophysics Data System (ADS)

    Bokshi, Arkaprava; Dickinson, David; Wilson, Howard

    2014-10-01

    Toroidal drift instabilities, such as the ion-temperature gradient (ITG) mode, are likely drivers of turbulent transport in tokamaks. Depending on the radial drive profile, two distinct mode structures can emerge: for a peaked profile, the violent Isolated Mode (IM) exists on the outboard-midplane, whereas for a linear profile, the more benign General Mode (GM) sits at the top/bottom of the plasma. The IM only exists in special conditions, so we expect the GM to usually drive turbulence. A new global code, based on an electrostatic gyrokinetic toroidal ITG model, has been developed and benchmarked to study the time-evolution of these linear modes. While we consider the ITG mode, the results are expected to be valid for most microinstabilities. A key result is that as the flow-shear evolves through a critical value, the GM evolves into the IM and then back to the GM. Curiously, the mode structure transiently passes through the violent IM phase independent of how fast the equilibrium evolves! For a pedestal evolving between ELMs, if a GM-IM-GM transition occurs, the burst in linear growth during the IM phase could drive a small ELM. The associated transport would maintain the pedestal pressure gradient below the peeling-ballooning limit, avoiding Type I ELMs.

  20. Hierarchical multi-class SVM with ELM kernel for epileptic EEG signal classification.

    PubMed

    Murugavel, A S Muthanantha; Ramakrishnan, S

    2016-01-01

    In this paper, a novel hierarchical multi-class SVM (H-MSVM) with extreme learning machine (ELM) as kernel is proposed to classify electroencephalogram (EEG) signals for epileptic seizure detection. A clinical EEG benchmark dataset having five classes, obtained from Department of Epileptology, Medical Center, University of Bonn, Germany, is considered in this work for validating the clinical utilities. Wavelet transform-based features such as statistical values, largest Lyapunov exponent, and approximate entropy are extracted and considered as input to the classifier. In general, SVM provides better classification accuracy, but takes more time for classification and also there is scope for a new multi-classification scheme. In order to mitigate the problem of SVM, a novel multi-classification scheme based on hierarchical approach, with ELM kernel, is proposed. Experiments have been conducted using holdout and cross-validation methods on the entire dataset. Metrics namely classification accuracy, sensitivity, specificity, and execution time are computed to analyze the performance of the proposed work. The results show that the proposed H-MSVM with ELM kernel is efficient in terms of better classification accuracy at a lesser execution time when compared to ANN, various multi-class SVMs, and other research works which use the same clinical dataset.

  1. Simulations of ELMs in realistic tokamak geometry with the nonlinear MHD code JOREK

    NASA Astrophysics Data System (ADS)

    Krebs, Isabel; Hoelzl, Matthias; Jardin, Stephen; Lackner, Karl; Guenter, Sibylle; Max-Planck/Princeton CenterPlasma Physics Collaboration

    2013-10-01

    Edge-localized modes (ELMs) are relaxation-oscillation instabilities which occur at the edge of high confinement (H-mode) plasmas, ejecting particles and energy. The suitability of H-mode as operational regime for future fusion devices depends crucially on the occurrence and detailed dynamics of ELMs. We simulate ELMs in realistic ASDEX Upgrade geometry including the scrape-off layer using the nonlinear MHD code JOREK. Emphasis is put on including many toroidal Fourier harmonics in the simulations in order to study nonlinear interaction between these. Several experimental observations, such as a toroidal and poloidal localization of the perturbation and a drive of Fourier components with low toroidal mode numbers, are reproduced by the simulations. A simple model describing the three-wave interaction by quadratic terms in the equations is used to explain and interpret the nonlinear evolution of the toroidal Fourier spectrum in the simulations. It is investigated how sheared toroidal plasma rotation influences the nonlinear coupling between the toroidal Fourier harmonics. A benchmark of the two-fluid versions of JOREK and M3D-C1 is in progress.

  2. Lithium granule ablation and penetration during ELM pacing experiments at DIII-D

    SciTech Connect

    Lunsford, R.; Bortolon, A.; Roquemore, A. L.; Mansfield, D. K.; Nagy, A.; Maingi, R.; Parks, P. B.; Jackson, G.; Gilson, E.; Chrobak, C. P.

    2016-05-25

    At DIII-D, lithium granules were radially injected into the plasma at the outer midplane to trigger and pace edge localized modes (ELMs). Granules ranging in size from 300 to 1000 microns were horizontally launched into H-mode discharges with velocities near 100 m/s, and granule to granule injection frequencies less than 500 Hz. While the smaller granules were only successful in triggering ELMs approximately 20% of the time, the larger granules regularly demonstrated ELM triggering efficiencies of greater than 80%. A fast visible camera looking along the axis of injection observed the ablation of the lithium granules. We used the duration of ablation as a benchmark for a neutral gas shielding calculation, and approximated the ablation rate and mass deposition location for the various size granules, using measured edge plasma profiles as inputs. In conclusion, this calculation suggests that the low triggering efficiency of the smaller granules is due to the inability of these granules to traverse the steep edge pressure gradient region and reach the top of the pedestal prior to full ablation.

  3. The Calibration of High-Speed Camera Imaging System for ELMs Observation on EAST Tokamak

    NASA Astrophysics Data System (ADS)

    Fu, Chao; Zhong, Fangchuan; Hu, Liqun; Yang, Jianhua; Yang, Zhendong; Gan, Kaifu; Zhang, Bin; East Team

    2016-09-01

    A tangential fast visible camera has been set up in EAST tokamak for the study of edge MHD instabilities such as ELM. To determine the 3-D information from CCD images, Tsai's two-stage technique was utilized to calibrate the high-speed camera imaging system for ELM study. By applying tiles of the passive stabilizers in the tokamak device as the calibration pattern, transformation parameters for transforming from a 3-D world coordinate system to a 2-D image coordinate system were obtained, including the rotation matrix, the translation vector, the focal length and the lens distortion. The calibration errors were estimated and the results indicate the reliability of the method used for the camera imaging system. Through the calibration, some information about ELM filaments, such as positions and velocities were obtained from images of H-mode CCD videos. supported by National Natural Science Foundation of China (No. 11275047), the National Magnetic Confinement Fusion Science Program of China (No. 2013GB102000)

  4. Lithium granule ablation and penetration during ELM pacing experiments at DIII-D

    DOE PAGES

    Lunsford, R.; Bortolon, A.; Roquemore, A. L.; ...

    2016-05-25

    At DIII-D, lithium granules were radially injected into the plasma at the outer midplane to trigger and pace edge localized modes (ELMs). Granules ranging in size from 300 to 1000 microns were horizontally launched into H-mode discharges with velocities near 100 m/s, and granule to granule injection frequencies less than 500 Hz. While the smaller granules were only successful in triggering ELMs approximately 20% of the time, the larger granules regularly demonstrated ELM triggering efficiencies of greater than 80%. A fast visible camera looking along the axis of injection observed the ablation of the lithium granules. We used the durationmore » of ablation as a benchmark for a neutral gas shielding calculation, and approximated the ablation rate and mass deposition location for the various size granules, using measured edge plasma profiles as inputs. In conclusion, this calculation suggests that the low triggering efficiency of the smaller granules is due to the inability of these granules to traverse the steep edge pressure gradient region and reach the top of the pedestal prior to full ablation.« less

  5. Lithium granule ablation and penetration during ELM pacing experiments at DIII-D

    SciTech Connect

    Lunsford, R.; Bortolon, A.; Roquemore, A. L.; Mansfield, D. K.; Nagy, A.; Maingi, R.; Parks, P. B.; Jackson, G.; Gilson, E.; Chrobak, C. P.

    2016-05-25

    At DIII-D, lithium granules were radially injected into the plasma at the outer midplane to trigger and pace edge localized modes (ELMs). Granules ranging in size from 300 to 1000 microns were horizontally launched into H-mode discharges with velocities near 100 m/s, and granule to granule injection frequencies less than 500 Hz. While the smaller granules were only successful in triggering ELMs approximately 20% of the time, the larger granules regularly demonstrated ELM triggering efficiencies of greater than 80%. A fast visible camera looking along the axis of injection observed the ablation of the lithium granules. We used the duration of ablation as a benchmark for a neutral gas shielding calculation, and approximated the ablation rate and mass deposition location for the various size granules, using measured edge plasma profiles as inputs. In conclusion, this calculation suggests that the low triggering efficiency of the smaller granules is due to the inability of these granules to traverse the steep edge pressure gradient region and reach the top of the pedestal prior to full ablation.

  6. Coupled Kinetic-MHD Simulations of Divertor Heat Load with ELM Perturbations

    NASA Astrophysics Data System (ADS)

    Cummings, Julian; Chang, C. S.; Park, Gunyoung; Sugiyama, Linda; Pankin, Alexei; Klasky, Scott; Podhorszki, Norbert; Docan, Ciprian; Parashar, Manish

    2010-11-01

    The effect of Type-I ELM activity on divertor plate heat load is a key component of the DOE OFES Joint Research Target milestones for this year. In this talk, we present simulations of kinetic edge physics, ELM activity, and the associated divertor heat loads in which we couple the discrete guiding-center neoclassical transport code XGC0 with the nonlinear extended MHD code M3D using the End-to-end Framework for Fusion Integrated Simulations, or EFFIS. In these coupled simulations, the kinetic code and the MHD code run concurrently on the same massively parallel platform and periodic data exchanges are performed using a memory-to-memory coupling technology provided by EFFIS. The M3D code models the fast ELM event and sends frequent updates of the magnetic field perturbations and electrostatic potential to XGC0, which in turn tracks particle dynamics under the influence of these perturbations and collects divertor particle and energy flux statistics. We describe here how EFFIS technologies facilitate these coupled simulations and discuss results for DIII-D, NSTX and Alcator C-Mod tokamak discharges.

  7. The Rock Elm meteorite impact structure, Wisconsin: Geology and shock-metamorphic effects in quartz

    USGS Publications Warehouse

    French, B.M.; Cordua, W.S.; Plescia, J.B.

    2004-01-01

    The Rock Elm structure in southwest Wisconsin is an anomalous circular area of highly deformed rocks, ???6.5 km in diameter, located in a region of virtually horizontal undeformed sedimentary rocks. Shock-produced planar microstructures (PMs) have been identified in quartz grains in several lithologies associated with the structure: sandstones, quartzite pebbles, and breccia. Two distinct types of PMs are present: P1 features, which appear identical to planar fractures (PFs or cleavage), and P2 features, which are interpreted as possible incipient planar deformation features (PDFs). The latter are uniquely produced by the shock waves associated with meteorite impact events. Both types of PMs are oriented parallel to specific crystallographic planes in the quartz, most commonly to c(0001), ??112??2, and r/z101??1. The association of unusual, structurally deformed strata with distinct shock-produced microdeformation features in their quartz-bearing rocks establishes Rock Elm as a meteorite impact structure and supports the view that the presence of multiple parallel cleavages in quartz may be used independently as a criterion for meteorite impact. Preliminary paleontological studies indicate a minimum age of Middle Ordovician for the Rock Elm structure. A similar age estimate (450-400 Ma) is obtained independently by combining the results of studies of the general morphology of complex impact structures with estimated rates of sedimentation for the region. Such methods may be applicable to dating other old and deeply eroded impact structures formed in sedimentary target rocks.

  8. Power Law Regression Analysis of Heat Flux Width in Type I ELMs

    NASA Astrophysics Data System (ADS)

    Stephens, C. D.; Makowski, M. A.; Leonard, A. W.; Osborne, T. H.

    2014-10-01

    In this project, a database of Type I ELM characteristics has been assembled and will be used to investigate possible dependencies of the heat flux width on physics and engineering parameters. At the edge near the divertor, high impulsive heat loads are imparted onto the surface. The impact of these ELMs can cause a reduction in divertor lifetime if the heat flux is great enough due to material erosion. A program will be used to analyze data, extract relevant, measurable quantities, and record the quantities in the table. Care is taken to accurately capture the complex space/time structure of the ELM. Then correlations between discharge and equilibrium parameters will be investigated. Power law regression analysis will be used to help determine the dependence of the heat flux width on these various measurable quantities and parameters. This will enable us to better understand the physics of heat flux at the edge. Work supported in part by the National Undergraduate Fellowship Program in Plasma Physics and Fusion Energy Sciences and the US DOE under DE-FG02-04ER54761, DE-AC52-07NA27344, DE-FC02-04ER54698.

  9. Pedestal structure and inter-ELM evolution for different main ion species in ASDEX Upgrade

    NASA Astrophysics Data System (ADS)

    Laggner, F. M.; Wolfrum, E.; Cavedon, M.; Mink, F.; Bernert, M.; Dunne, M. G.; Schneider, P. A.; Kappatou, A.; Birkenmeier, G.; Fischer, R.; Willensdorfer, M.; Aumayr, F.

    2017-05-01

    In tokamak plasmas with different main ion species, a change in confinement occurs, known as the isotope effect. Experiments comparing hydrogen (H), deuterium (D), and helium (4He) plasmas have been performed to identify processes that define the pedestal structure and evolution in between the crashes of edge localized modes (ELMs). The pedestal top electron densities and temperatures have been matched to compare the pedestal shape and stability. In the D and H discharges, the pedestal electron temperature profiles do not differ, whereas the density profile in H has shallower gradients. Furthermore, the heat flux across the pedestal in H is roughly a factor of two higher than in D. In 4He plasmas at similar stored energy, the pedestal top electron density is roughly a factor of 1.5 larger than in the references owing to the larger effective charge. The peeling-ballooning theory, which is independent of the main ion species mass, can sufficiently describe the pedestal stability in the hydrogenic plasmas. The inter-ELM pedestal evolution has the same sequence of recovery phases for all investigated species, giving evidence that similar mechanisms are acting in the pedestals. This is further supported by a similar evolution of the inter-ELM magnetic signature and the corresponding toroidal structure.

  10. English Language Teaching Profile: Belgium (Dutch Speaking).

    ERIC Educational Resources Information Center

    British Council, London (England). English-Teaching Information Centre.

    This profile in outline form discusses the English language teaching situation in the Dutch-speaking and French-speaking areas of Belgium. The situation in the Dutch-speaking region, which includes Flanders and Brussels (the latter having both Dutch and French as official languages), is described in terms of the extent of English instruction…

  11. Connection between plasma response and resonant magnetic perturbation (RMP) edge localized mode (ELM) suppression in DIII-D [Connection between plasma response and RMP ELM suppression in DIII-D

    SciTech Connect

    Wingen, Andreas; Ferraro, Nathaniel M.; Shafer, Morgan W.; Unterberg, Ezekial A.; Canik, John M.; Evans, Todd E.; Hillis, Donald Lee; Hirshman, Steven Paul; Seal, Sudip K.; Snyder, Philip B.; Sontag, Aaron C.

    2015-09-03

    Calculations of the plasma response to applied non-axisymmetric fields in several DIII-D discharges show that predicted displacements depend strongly on the edge current density. This result is found using both a linear two-fluid-MHD model (M3D-C1) and a nonlinear ideal-MHD model (VMEC). Furthermore, it is observed that the probability of a discharge being edge localized mode (ELM)-suppressed is most closely related to the edge current density, as opposed to the pressure gradient. It is found that discharges with a stronger kink response are closer to the peeling–ballooning stability limit in ELITE simulations and eventually cross into the unstable region, causing ELMs to reappear. Thus for effective ELM suppression, the RMP has to prevent the plasma from generating a large kink response, associated with ELM instability. Experimental observations are in agreement with the finding; discharges which have a strong kink response in the MHD simulations show ELMs or ELM mitigation during the RMP phase of the experiment, while discharges with a small kink response in the MHD simulations are fully ELM suppressed in the experiment by the applied resonant magnetic perturbation. The results are cross-checked against modeled 3D ideal MHD equilibria using the VMEC code. The procedure of constructing optimal 3D equilibria for diverted H-mode discharges using VMEC is presented. As a result, kink displacements in VMEC are found to scale with the edge current density, similar to M3D-C1, but the displacements are smaller. A direct correlation in the flux surface displacements to the bootstrap current is shown.

  12. Intermediate-k density and magnetic field fluctuations during inter-ELM pedestal evolution in MAST

    NASA Astrophysics Data System (ADS)

    Hillesheim, J. C.; Dickinson, D.; Roach, C. M.; Saarelma, S.; Scannell, R.; Kirk, A.; Crocker, N. A.; Peebles, W. A.; Meyer, H.; the MAST Team

    2016-01-01

    Measurements of local density and magnetic field fluctuations near the pedestal top, conditionally averaged over the edge localized mode (ELM) cycle, have been made in Mega Amp Spherical Tokamak (MAST). A Doppler backscattering (DBS) system installed at MAST was used to measure intermediate-k ≤ft({{k}\\bot}{ρi}≈ 3~\\text{to}~4\\right) density fluctuations at the top of the pedestal. A novel diagnostic technique combining DBS with cross-polarization scattering (CP-DBS) enabled magnetic field fluctuations to also be locally measured at similar wave numbers. Polarization isolation and other effects for CP-DBS are discussed. Both measurements were used in a series of high-β ≤ft({βn}≈ 4.0\\right. -4.5) MAST plasmas with large type-I ELMs with an ˜ 8~\\text{to}~9~\\text{ms} period where microtearing modes (MTMs) had been predicted to be unstable in similar conditions (Dickinson 2012 Phys. Rev. Lett. 108 135002). The measured density fluctuation level increased by a factor of about 4 between 2 and 4 ms after the ELM, which was correlated with the recovery of the density profile while the temperature pedestal height continued to increase slowly. Magnetic field fluctuations showed different temporal behaviors, slowly increasing throughout the ELM cycle as the local β increased. Linear GS2 calculations show both MTM and electron temperature gradient (ETG) modes unstable at similar wave numbers as the measurements (although with more overlap between ETG wave numbers and diagnostic spectral resolution) at the top of the pedestal, along with kinetic ballooning modes are unstable lower in the pedestal (at larger wavelengths). The inferred ratio of fluctuation levels from experiment was ≤ft(δ B/B\\right)/≤ft(δ n/n\\right)≈ 1/20 . The comparable ratios from GS2 were ≤ft(δ B/B\\right)/≤ft(δ n/n\\right)≈ 0.4 for the MTM and ≤ft(δ B/B\\right)/≤ft(δ n/n\\right)≈ 0.02 for the ETG. Both the experimental wave number range and the fluctuation ratio

  13. Impact of impurity seeding and divertor conditions on transitions, pedestal structure and ELMs

    NASA Astrophysics Data System (ADS)

    Dunne, M. G.

    2017-02-01

    Future devices will require a high scrape-off later (SOL) density and impurity seeding to avoid high-Z sputtering. However, these operational parameters are not included in present-day scaling laws, making extrapolations to larger devices difficult. As such, understanding the physics of such effects is vital in order to design the operational scenarios most favorable to high fusion gain. This review presents the favorable lowering of L-H transition power by changing to metal walled devices and sumarises the effects currently thought to be responsible for how SOL geometry can play a role in determining this threshold. Experimental observations on changes to the pedestal structure with main ion fuelling and low-, medium-, and high-Z impurity seeding are presented. These results, from several devices, show that main ion fuelling or high density operation can result in a lower pedestal top pressure, and hence reduced stored energy, while impurity seeding can recover this lost pressure. Particular focus is given to nitrogen seeded discharges and the recovery of pedestal parameters (notably high {{T}\\text{e,\\text{ped}}} ) in JET and AUG since the changeover to metal walls in these devices. Lithium seeding is also emerging as a strong actuator in pedestal dynamics, with results ranging from a prolonged inter-ELM period to completely ELM-free scenarios on different devices. ELM dynamics are also presented in each section, with nitrogen seeding offering a probe into the structure of the ELM and demonstrating the difference between the initial ELM crash, likely due to a sharp MHD event, and a prolonged second phase, the origin of which remains unkown. Finally, modelling of the pedestal in impurity seeded scenarios reveals a common effect in the position of the density profile. Either through mode excitation near to the separatrix or an altered fuelling profile, seeding of impurities results in an inward shift of the density profile. This inward shift improves MHD stability

  14. Experimental estimation of tungsten impurity sputtering due to Type I ELMs in JET-ITER-like wall using pedestal electron cyclotron emission and target Langmuir probe measurements

    NASA Astrophysics Data System (ADS)

    Guillemaut, C.; Jardin, A.; Horacek, J.; Borodkina, I.; Autricque, A.; Arnoux, G.; Boom, J.; Brezinsek, S.; Coenen, J. W.; De La Luna, E.; Devaux, S.; Eich, T.; Harting, D.; Kirschner, A.; Lipschultz, B.; Matthews, G. F.; Meigs, A.; Moulton, D.; O'Mullane, M.; Stamp, M.; contributors, JET

    2016-02-01

    The ITER baseline scenario, with 500 MW of DT fusion power and Q = 10, will rely on a Type I ELMy H-mode and will be achieved with a tungsten (W) divertor. W atoms sputtered from divertor targets during mitigated ELMs are expected to be the dominant source in ITER. W impurity concentration in the plasma core can dramatically degrade its performance and lead to potentially damaging disruptions. Understanding the physics of the target W source due to sputtering during ELMs and inter-ELMs is important and can be helped by experimental measurements with improved precision. It has been established that the ELMy target ion impact energy has a simple linear dependence with the pedestal electron temperature measured by Electron Cyclotron Emission (ECE). It has also been shown that Langmuir Probes (LP) ion flux measurements are reliable during ELMs due to the surprisingly low electron temperature. Therefore, in this paper, LP and ECE measurements in JET-ITER-Like-Wall (ILW) unseeded Type I ELMy H-mode experiments have been used to estimate the W sputtering flux from divertor targets in ELM and inter-ELM conditions. Comparison with similar estimates using W I spectroscopy measurements shows a reasonable agreement for the ELM and inter-ELM W source. The main advantage of the method involving LP measurements is the very high time resolution of the diagnostic (˜10 μs) allowing very precise description of the W sputtering source during ELMs.

  15. Connection between plasma response and resonant magnetic perturbation (RMP) edge localized mode (ELM) suppression in DIII-D

    NASA Astrophysics Data System (ADS)

    Wingen, A.; Ferraro, N. M.; Shafer, M. W.; Unterberg, E. A.; Canik, J. M.; Evans, T. E.; Hillis, D. L.; Hirshman, S. P.; Seal, S. K.; Snyder, P. B.; Sontag, A. C.

    2015-10-01

    Calculations of the plasma response to applied non-axisymmetric fields in several DIII-D discharges show that predicted displacements depend strongly on the edge current density. This result is found using both a linear two-fluid-MHD model (M3D-C1) and a nonlinear ideal-MHD model (VMEC). Furthermore, it is observed that the probability of a discharge being edge localized mode (ELM)-suppressed is most closely related to the edge current density, as opposed to the pressure gradient. It is found that discharges with a stronger kink response are closer to the peeling-ballooning stability limit in ELITE simulations and eventually cross into the unstable region, causing ELMs to reappear. Thus for effective ELM suppression, the RMP has to prevent the plasma from generating a large kink response, associated with ELM instability. Experimental observations are in agreement with the finding; discharges which have a strong kink response in the MHD simulations show ELMs or ELM mitigation during the RMP phase of the experiment, while discharges with a small kink response in the MHD simulations are fully ELM suppressed in the experiment by the applied resonant magnetic perturbation. The results are cross-checked against modeled 3D ideal MHD equilibria using the VMEC code. The procedure of constructing optimal 3D equilibria for diverted H-mode discharges using VMEC is presented. Kink displacements in VMEC are found to scale with the edge current density, similar to M3D-C1, but the displacements are smaller. A direct correlation in the flux surface displacements to the bootstrap current is shown.

  16. Mini-Mental State Examination subscores indicate visuomotor deficits in Alzheimer's disease patients: A cross-sectional study in a Dutch population.

    PubMed

    de Boer, Casper; Mattace-Raso, Francesco; van der Steen, Johannes; Pel, Johan J M

    2014-10-01

    In diagnostics of Alzheimer's disease (AD), the Mini-Mental State Examination (MMSE) questionnaire is frequently used to test cognitive decline. The final subtest of the MMSE, in which patients have to copy two interlocking pentagons, tests a variety of visuomotor functions. Recent imaging studies suggest that visuomotor function could decline in early stage AD, as a result of degeneration of the brain networks involved. The goal of the present study was to compare memory and visuomotor function in AD patients, reflected by the MMSE subscores for orientation, recall and interlocking pentagons. The MMSE subscores for orientation, recall and interlocking pentagons of 125 AD patients was extracted from their medical history. Patients were divided into three groups based on disease duration. Using related-samples Wilcoxon signed-rank tests, the performance between subtests using normalized subscores was compared within each group. In all three groups, the subscores of recall and interlocking pentagons were significantly lower than orientation. No differences were found between the subscores of recall and interlocking pentagons. The presented data suggest that memory function and visuomotor function are equally impaired in the present study population. This could indicate that visuomotor dysfunction might be a more important clinical feature of AD than is currently assumed. This knowledge can be used to develop new tests and markers for AD reflecting deficits in visuomotor functions, such as quantification of eye and hand movements. © 2013 Japan Geriatrics Society.

  17. Dutch museum marks Einstein anniversary

    NASA Astrophysics Data System (ADS)

    van Calmthout, Matijn

    2016-01-01

    A new painting of Albert Einstein's field equation from his 1915 general theory of relativity was unveiled in a ceremony in November 2015 by the Dutch physicist Robbert Dijkgraaf, who is director of the Princeton Institute for Advanced Study in the US.

  18. Metalinguistic Awareness in Dutch Immigrants.

    ERIC Educational Resources Information Center

    de Bot, Kees

    1992-01-01

    Data are presented on some aspects of metalinguistic awareness in Dutch adults who emigrated to Australia at least 25 years ago. The findings show that the migrants do not differ significantly from a control group in the Netherlands, suggesting that first-language metalinguistic skills are extremely resistant to attrition. (Contains nine…

  19. An Expert Diagnosis System for Parkinson Disease Based on Genetic Algorithm-Wavelet Kernel-Extreme Learning Machine.

    PubMed

    Avci, Derya; Dogantekin, Akif

    2016-01-01

    Parkinson disease is a major public health problem all around the world. This paper proposes an expert disease diagnosis system for Parkinson disease based on genetic algorithm- (GA-) wavelet kernel- (WK-) Extreme Learning Machines (ELM). The classifier used in this paper is single layer neural network (SLNN) and it is trained by the ELM learning method. The Parkinson disease datasets are obtained from the UCI machine learning database. In wavelet kernel-Extreme Learning Machine (WK-ELM) structure, there are three adjustable parameters of wavelet kernel. These parameters and the numbers of hidden neurons play a major role in the performance of ELM. In this study, the optimum values of these parameters and the numbers of hidden neurons of ELM were obtained by using a genetic algorithm (GA). The performance of the proposed GA-WK-ELM method is evaluated using statical methods such as classification accuracy, sensitivity and specificity analysis, and ROC curves. The calculated highest classification accuracy of the proposed GA-WK-ELM method is found as 96.81%.

  20. Recurrent stroke after transient ischaemic attack or minor ischaemic stroke: does the distinction between small and large vessel disease remain true to type? Dutch TIA Trial Study Group.

    PubMed Central

    Kappelle, L J; van Latum, J C; van Swieten, J C; Algra, A; Koudstaal, P J; van Gijn, J

    1995-01-01

    The incidence and vascular type of recurrent ischaemic stroke was studied in patients with supratentorial transient ischaemic attacks or non-disabling ischaemic strokes, who were treated with aspirin (30 or 283 mg). Patients were divided into groups with small vessel disease (SVD) (n = 1216) or large vessel disease (LVD) (n = 1221) on the grounds of their clinical features and CT at baseline. Patients with evidence of both SVD and LVD (n = 180) were excluded from further analyses. During follow up (mean 2.6 years) annual stroke rate was 3.6% in both groups. Of the 107 patients with SVD at baseline who had recurrent strokes, 83 proved to have an identifiable infarct: 30 (28%) again had a small vessel infarct, 39 (36%) had a large vessel ischaemic stroke and in 14 (13%) the recurrent ischaemic stroke was in the posterior fossa. Of the 110 patients with LVD at baseline and recurrent stroke, 91 had an identifiable infarct: 67 (61%) again had a large vessel ischaemic stroke, 16 (15%) had a small vessel ischaemic stroke, and eight (7%) had the recurrent ischaemic stroke in the posterior fossa. Thus patients with a transient ischaemic attack or non-disabling ischaemic stroke caused by LVD were more likely to have an ischaemic stroke of the same vessel type during follow up than patients with SVD (relative risk 2.2; 95% confidence interval 1.5-3.4). Possible explanations for this difference are: (1) patients with a small vessel ischaemic stroke at baseline had both SVD and LVD or were misdiagnosed; (2) recurrent small vessel ischaemic stroke may have occurred more often than reported, because they were silent or only minimally disabling; (3) recurring large vessel ischaemic strokes occurring in patients initially diagnosed as having SVD might have been related to potential cardiac sources of emboli that had not been previously recognized; (4) the antiplatelet drug aspirin (30 or 283 mg) prescribed in this patient group may have prevented thrombosis in small vessels better

  1. Genetic parameters of insect bite hypersensitivity in Dutch Friesian broodmares.

    PubMed

    Schurink, A; Ducro, B J; Heuven, H C M; van Arendonk, J A M

    2011-05-01

    Insect bite hypersensitivity (IBH) is a seasonal allergic skin disease in horses caused by bites of certain Culicoides spp. The aim of our study was to investigate the maternal effect on IBH and to estimate the heritability and repeatability of IBH in the Dutch Friesian horse population. Data consisted of 3,453 Dutch Friesian broodmares with 3,763 visual observations on IBH clinical symptoms scored by 12 inspectors during organized foal inspections in 2004 and 2008. Nine percent of the mares (n = 310) were scored in both years. Mares descended from 144 sires and 2,554 dams and 26.2% of the dams (n = 669) had more than 1 offspring in the data set (range: 2 to 6). Insect bite hypersensitivity was analyzed as a binary trait with a threshold animal model with and without a maternal effect, using a Bayesian approach. Observed IBH prevalence in Dutch Friesian broodmare population was 18.2%. Heritability on the liability scale was 0.16 (SD = 0.06); heritability on the observed scale was 0.07; and repeatability was 0.89 (SD = 0.03). Maternal effect was 0.17 (SD = 0.06) and significantly differed from zero, although the animal model without a maternal effect fitted the data better. These results show that genetic and permanent environmental factors affect IBH in Dutch Friesian horses. The dam affected the IBH development of her offspring through an additive genetic influence but also by being part of their rearing environment.

  2. Effects of inoculation timing on symptom development in Ulmus americana L.

    Treesearch

    Garrett L. Beier; Benjamin W. Held; Chad P. Giblin; Robert A. Blanchette

    2017-01-01

    Field inoculation trials are an important component of screening American elms (Ulmus americana) for levels of resistance to Dutch elm disease. A major concern in screening is variability in disease ratings from year to year. Previous studies have demonstrated that timing of inoculation can have a significant impact on disease susceptibility. In...

  3. Typification of infrageneric names in Ulmus L.

    USDA-ARS?s Scientific Manuscript database

    The elms (the genus Ulmus) are one of the most important tree crops for the $4.7billion per year U.S. nursery industry, but utilization of these plants has been limited in recent decades by introduced diseases, especially Dutch elm disease. Research and breeding for disease resistance have been base...

  4. Screening tests of chemical deterrents

    Treesearch

    Arthur R. Hastings; Morton Beroza

    1961-01-01

    Despite intensive research and zealous control efforts, the Dutch elm disease continues to kill valuable ornamental and wild elm trees over wide areas in the United States and Canada. Control of the disease at present is based on sanitation, the removal of dead and dying ornamental trees, and use of insecticides to kill the insects that carry the disease. The primary...

  5. THE ELM SURVEY. I. A COMPLETE SAMPLE OF EXTREMELY LOW-MASS WHITE DWARFS

    SciTech Connect

    Brown, Warren R.; Kilic, Mukremin; Kenyon, Scott J.; Prieto, Carlos Allende E-mail: mkilic@cfa.harvard.ed E-mail: callende@iac.e

    2010-11-10

    We analyze radial velocity observations of the 12 extremely low-mass (ELM), with {<=}0.25 M{sub sun}, white dwarfs (WDs) in the MMT Hypervelocity Star Survey. Eleven of the twelve WDs are binaries with orbital periods shorter than 14 hr; the one non-variable WD is possibly a pole-on system among our non-kinematically selected targets. Our sample is unique: it is complete in a well-defined range of apparent magnitude and color. The orbital mass functions imply that the unseen companions are most likely other WDs, although neutron star companions cannot be excluded. Six of the eleven systems with orbital solutions will merge within a Hubble time due to the loss of angular momentum through gravitational wave radiation. The quickest merger is J0923+3028, a g = 15.7 ELM WD binary with a 1.08 hr orbital period and a {<=}130 Myr merger time. The chance of a supernova Ia event among our ELM WDs is only 1%-7%, however. Three binary systems (J0755+4906, J1233+1602, and J2119-0018) have extreme mass ratios and will most likely form stable mass-transfer AM CVn systems. Two of these objects, SDSS J1233+1602 and J2119-0018, are the lowest surface gravity WDs ever found; both show Ca II absorption likely from accretion of circumbinary material. We predict that at least one of our WDs is an eclipsing detached double WD system, important for constraining helium core WD models.

  6. The ELM Survey. I. A Complete Sample of Extremely Low-mass White Dwarfs

    NASA Astrophysics Data System (ADS)

    Brown, Warren R.; Kilic, Mukremin; Allende Prieto, Carlos; Kenyon, Scott J.

    2010-11-01

    We analyze radial velocity observations of the 12 extremely low-mass (ELM), with <=0.25 M sun, white dwarfs (WDs) in the MMT Hypervelocity Star Survey. Eleven of the twelve WDs are binaries with orbital periods shorter than 14 hr; the one non-variable WD is possibly a pole-on system among our non-kinematically selected targets. Our sample is unique: it is complete in a well-defined range of apparent magnitude and color. The orbital mass functions imply that the unseen companions are most likely other WDs, although neutron star companions cannot be excluded. Six of the eleven systems with orbital solutions will merge within a Hubble time due to the loss of angular momentum through gravitational wave radiation. The quickest merger is J0923+3028, a g = 15.7 ELM WD binary with a 1.08 hr orbital period and a <=130 Myr merger time. The chance of a supernova Ia event among our ELM WDs is only 1%-7%, however. Three binary systems (J0755+4906, J1233+1602, and J2119-0018) have extreme mass ratios and will most likely form stable mass-transfer AM CVn systems. Two of these objects, SDSS J1233+1602 and J2119-0018, are the lowest surface gravity WDs ever found; both show Ca II absorption likely from accretion of circumbinary material. We predict that at least one of our WDs is an eclipsing detached double WD system, important for constraining helium core WD models. Based on observations obtained at the MMT Observatory, a joint facility of the Smithsonian Institution and the University of Arizona.

  7. Connection between plasma response and resonant magnetic perturbation (RMP) edge localized mode (ELM) suppression in DIII-D [Connection between plasma response and RMP ELM suppression in DIII-D

    DOE PAGES

    Wingen, Andreas; Ferraro, Nathaniel M.; Shafer, Morgan W.; ...

    2015-09-03

    Calculations of the plasma response to applied non-axisymmetric fields in several DIII-D discharges show that predicted displacements depend strongly on the edge current density. This result is found using both a linear two-fluid-MHD model (M3D-C1) and a nonlinear ideal-MHD model (VMEC). Furthermore, it is observed that the probability of a discharge being edge localized mode (ELM)-suppressed is most closely related to the edge current density, as opposed to the pressure gradient. It is found that discharges with a stronger kink response are closer to the peeling–ballooning stability limit in ELITE simulations and eventually cross into the unstable region, causing ELMsmore » to reappear. Thus for effective ELM suppression, the RMP has to prevent the plasma from generating a large kink response, associated with ELM instability. Experimental observations are in agreement with the finding; discharges which have a strong kink response in the MHD simulations show ELMs or ELM mitigation during the RMP phase of the experiment, while discharges with a small kink response in the MHD simulations are fully ELM suppressed in the experiment by the applied resonant magnetic perturbation. The results are cross-checked against modeled 3D ideal MHD equilibria using the VMEC code. The procedure of constructing optimal 3D equilibria for diverted H-mode discharges using VMEC is presented. As a result, kink displacements in VMEC are found to scale with the edge current density, similar to M3D-C1, but the displacements are smaller. A direct correlation in the flux surface displacements to the bootstrap current is shown.« less

  8. Characteristics of the TFTR limiter H-mode: The transition, ELMs, transport and confinement

    SciTech Connect

    Bush, C.E.; Bretz, N.; Nazikian, R.; Stratton, B.C.; Synakowski, E.; Taylor, G. Budny, R.; Ramsey, A.T.; Scott, S.D.; Bell, M.; Bell, R.; Biglari, H.; Bitter, M.; Darrow, D.S.; Efthimion, P.; Fredrickson, E.D.; Hill, K.; Hsuan, H.; Kilpatrick, S.; McGuire, K.M.; Manos, D.; Mansfield, D.; Medley, S.S.; Mueller, D.; Park, H.; Paul, S.; Sabbagh, S.; Schivell, J.; Thompson, M.; Towner, H.H.; Wieland, R.M.; Zarnstorff, M.C.; Zweben, S.; Fonck, R.; Nagayama, Y.

    1992-11-01

    H-Modes obtained through transitions from the supershot regime have been studied on TFTR. The characteristics of these H-modes are similar to those found on other tokamaks with one main exception, the density prof:des can be highly peaked. In the best cases the enhanced confinement in the core of the initial supershot is retained in the H-mode phase, while the confinement in a broad edge region is enhanced. Thus in TFTR, all of the important physics of H-modes such as transitions, enhanced edge confinement, ELMs and other phenomena are studied in a large circular limiter tokamak with the added feature of centrally peaked density profiles and the advantage of an extensive set of diagnostics. The threshold power for the transition is found to be a linear function of plasma current. Transitions and ELMs are affected by the mix of co-and counter-neutral beam injection (NBI) and by perturbations introduced by pellet injection, gas puffing, and current ramping before and during NBI. Fluctuations near both transition and ELM events have been characterized. High frequency magnetic fluctuations in the range {ge} 100--250 kHz usually decrease during the transition. Microwave scattering spectra of density fluctuations in the plasma edge show a feature at high frequency during the H-mode, which is not observed in the plasma core and which is consistent with an edge poloidal rotation velocity, V{sub {theta}}, of {approximately} 10{sup 4} m/s. The fluctuations begin at the transition, propagate in the direction of electron diamagnetic drift, and have modulation correlated with ELMs. Several TFTR H-modes showed a modest improvement in confinement over that of the supershots from which they originated, and an understanding of these may eventually lead to a plasma with the combined advantages of both the supershot and the H-mode. The characteristics and physics of the TFTR H-modes are considered relative to other tokamaks and in light of various theoretical studies.

  9. Program ELM: A tool for rapid thermal-hydraulic analysis of solid-core nuclear rocket fuel elements

    NASA Technical Reports Server (NTRS)

    Walton, James T.

    1992-01-01

    This report reviews the state of the art of thermal-hydraulic analysis codes and presents a new code, Program ELM, for analysis of fuel elements. ELM is a concise computational tool for modeling the steady-state thermal-hydraulics of propellant flow through fuel element coolant channels in a nuclear thermal rocket reactor with axial coolant passages. The program was developed as a tool to swiftly evaluate various heat transfer coefficient and friction factor correlations generated for turbulent pipe flow with heat addition which have been used in previous programs. Thus, a consistent comparison of these correlations was performed, as well as a comparison with data from the NRX reactor experiments from the Nuclear Engine for Rocket Vehicle Applications (NERVA) project. This report describes the ELM Program algorithm, input/output, and validation efforts and provides a listing of the code.

  10. Host Acceptance and Larval Competition between the Invasive Banded and European Elm Bark Beetles, Scolytus schevyrewi and S. multistriatus (Coleoptera: Scolytidae): Potential Mechanisms for Competitive Displacement

    USDA-ARS?s Scientific Manuscript database

    A recent survey revealed that the newly invasive banded elm bark beetle, Scolytus schevyrewi, was much more abundant than the long-established European elm bark beetle, S. multistriatus, in areas of Colorado and Wyoming, USA. This study sought to determine whether competitive displacement of S. mul...

  11. Host acceptance and larval competition between the invasive banded and European elm bark beetles (Coleoptera: Scolytidae): Potential mechanisms for competitive displacement

    Treesearch

    J.C. Lee; S.J. Seybold

    2009-01-01

    A recent survey revealed that the newly invasive banded elm bark beetle, Scolytus schevyrewi, was much more abundant than the long-established European elm bark beetle, S. multistriatus, in areas of Colorado and Wyoming, USA. This study was initiated to determine whether competitive displacement of S. multistriatus...

  12. Connection between plasma response and resonant magnetic perturbation (RMP) edge localized mode (ELM) suppression in DIII-D

    DOE PAGES

    Wingen, Andreas; Ferraro, N. M.; Shafer, Morgan W.; ...

    2015-09-03

    Calculations of the plasma response to applied non-axisymmetric fields in several DIII-D discharges show that predicted displacements depend strongly on the edge current density. This result is found using both a linear two-fluid-MHD model (M3D-C1) and a nonlinear ideal-MHD model (VMEC). Furthermore, it is observed that the probability of a discharge being edge localized mode (ELM)-suppressed is most closely related to the edge current density, as opposed to the pressure gradient. It is found that discharges with a stronger kink response are closer to the peeling–ballooning stability limit in ELITE simulations and eventually cross into the unstable region, causing ELMsmore » to reappear. Thus for effective ELM suppression, the RMP has to prevent the plasma from generating a large kink response, associated with ELM instability. Experimental observations are in agreement with the finding; discharges which have a strong kink response in the MHD simulations show ELMs or ELM mitigation during the RMP phase of the experiment, while discharges with a small kink response in the MHD simulations are fully ELM suppressed in the experiment by the applied resonant magnetic perturbation. The results are cross-checked against modeled 3D ideal MHD equilibria using the VMEC code. The procedure of constructing optimal 3D equilibria for diverted H-mode discharges using VMEC is presented. As a result, kink displacements in VMEC are found to scale with the edge current density, similar to M3D-C1, but the displacements are smaller. A direct correlation in the flux surface displacements to the bootstrap current is shown.« less

  13. Comparison of ELM, GANN, WNN and empirical models for estimating reference evapotranspiration in humid region of Southwest China

    NASA Astrophysics Data System (ADS)

    Feng, Yu; Cui, Ningbo; Zhao, Lu; Hu, Xiaotao; Gong, Daozhi

    2016-05-01

    Reference evapotranspiration (ET0) is an essential component in hydrological ecological processes and agricultural water management. Accurate estimation of ET0 is of importance in improving irrigation efficiency, water reuse and irrigation scheduling. FAO-56 Penman-Monteith (P-M) model is recommended as the standard model to estimate ET0. Nevertheless, its application is limited due to the lack of required meteorological data. In this study, trained extreme learning machine (ELM), backpropagation neural networks optimized by genetic algorithm (GANN) and wavelet neural networks (WNN) models were developed to estimate ET0, and the performances of ELM, GANN, WNN, two temperature-based (Hargreaves and modified Hargreaves) and three radiation-based (Makkink, Priestley-Taylor and Ritchie) ET0 models in estimating ET0 were evaluated in a humid area of Southwest China. Results indicated that among the new proposed models, ELM and GANN models were much better than WNN model, and the temperature-based ELM and GANN models had better performance than Hargreaves and modified Hargreaves models, radiation-based ELM and GANN models had higher precision than Makkink, Priestley-Taylor and Ritchie models. Both of radiation-based ELM (RMSE ranging 0.312-0.332 mm d-1, Ens ranging 0.918-0.931, MAE ranging 0.260-0.300 mm d-1) and GANN models (RMSE ranging 0.300-0.333 mm d-1, Ens ranging 0.916-0.941, MAE ranging 0.2580-0.303 mm d-1) could estimate ET0 at an acceptable accuracy level, and are highly recommended for estimating ET0 without adequate meteorological data.

  14. Design methodology of Dutch banknotes

    NASA Astrophysics Data System (ADS)

    de Heij, Hans A. M.

    2000-04-01

    Since the introduction of a design methodology for Dutch banknotes, the quality of Dutch paper currency has improved in more than one way. The methodology is question provides for (i) a design policy, which helps fix clear objectives; (ii) design management, to ensure a smooth cooperation between the graphic designer, printer, papermaker an central bank, (iii) a program of requirements, a banknote development guideline for all parties involved. This systematic approach enables an objective selection of design proposals, including security features. Furthermore, the project manager obtains regular feedback from the public by conducting market surveys. Each new design of a Netherlands Guilder banknote issued by the Nederlandsche Bank of the past 50 years has been an improvement on its predecessor in terms of value recognition, security and durability.

  15. Variation in the prion protein sequence in Dutch goat breeds.

    PubMed

    Windig, J J; Hoving, R A H; Priem, J; Bossers, A; van Keulen, L J M; Langeveld, J P M

    2016-10-01

    Scrapie is a neurodegenerative disease occurring in goats and sheep. Several haplotypes of the prion protein increase resistance to scrapie infection and may be used in selective breeding to help eradicate scrapie. In this study, frequencies of the allelic variants of the PrP gene are determined for six goat breeds in the Netherlands. Overall frequencies in Dutch goats were determined from 768 brain tissue samples in 2005, 766 in 2008 and 300 in 2012, derived from random sampling for the national scrapie surveillance without knowledge of the breed. Breed specific frequencies were determined in the winter 2013/2014 by sampling 300 breeding animals from the main breeders of the different breeds. Detailed analysis of the scrapie-resistant K222 haplotype was carried out in 2014 for 220 Dutch Toggenburger goats and in 2015 for 942 goats from the Saanen derived White Goat breed. Nine haplotypes were identified in the Dutch breeds. Frequencies for non-wild type haplotypes were generally low. Exception was the K222 haplotype in the Dutch Toggenburger (29%) and the S146 haplotype in the Nubian and Boer breeds (respectively 7 and 31%). The frequency of the K222 haplotype in the Toggenburger was higher than for any other breed reported in literature, while for the White Goat breed it was with 3.1% similar to frequencies of other Saanen or Saanen derived breeds. Further evidence was found for the existence of two M142 haplotypes, M142 /S240 and M142 /P240 . Breeds vary in haplotype frequencies but frequencies of resistant genotypes are generally low and consequently selective breeding for scrapie resistance can only be slow but will benefit from animals identified in this study. The unexpectedly high frequency of the K222 haplotype in the Dutch Toggenburger underlines the need for conservation of rare breeds in order to conserve genetic diversity rare or absent in other breeds. © 2016 Blackwell Verlag GmbH.

  16. ELM phenomenon as an interaction between bootstrap-current driven peeling modes and pressure-driven ballooning modes

    NASA Astrophysics Data System (ADS)

    Saarelma, S.; Günter, S.; Kurki-Suonio, T.; Zehrfeld, H.-P.

    2000-05-01

    An ELMy ASDEX Upgrade plasma equilibrium is reconstructed taking into account the bootstrap current. The peeling mode stability of the equilibrium is numerically analysed using the GATO [1] code, and it is found that the bootstrap current can drive the plasma peeling mode unstable. A high-n ballooning mode stability analysis of the equilibria revealed that, while destabilizing the peeling modes, the bootstrap current has a stabilizing effect on the ballooning modes. A combination of these two instabilities is a possible explanation for the type I ELM phenomenon. A triangularity scan showed that increasing triangularity stabilizes the peeling modes and can produce ELM-free periods observed in the experiments.

  17. Dutch concentrate on specialties and market

    SciTech Connect

    Not Available

    1984-11-01

    The success of Dutch offshore multinational companies is said to be based on three factors: an ancient tradition of trade, an ability to forecast the commercial possibilities of technical innovation, and skill at adapting to the outlook of their trading partners. The Netherlands has produced two of the most technically successful companies in the North Sea, Royal Dutch/Shell and the Heerema company. Both tend to be regarded as multinational rather than specifically Dutch, but Dutch managements have had a profound effect on both companies' development.

  18. The Dutch Euthanasia Act and related issues.

    PubMed

    Legemaate, Johan

    2004-02-01

    In 2002 the Dutch Euthanasia Act came into force. This Act is the result of a lengthy developmental process. It codifies the requirements that have evolved in case law and medical ethics since 1973. Empirical data indicate that the Dutch euthanasia practice is stabilising. Euthanasia and assisted suicide occur in 2.7% of all deaths. Now that the Act has been passed, the focus is on improving the quality of medical decision-making. From an international perspective, the Dutch legislation is exceptional. However, it appears that other countries and international organisations are considering euthanasia legislation as well. It remains to be seen how influential the Dutch model will prove to be.

  19. Recrystallization and grain growth induced by ELMs-like transient heat loads in deformed tungsten samples.

    PubMed

    Suslova, A; El-Atwani, O; Sagapuram, D; Harilal, S S; Hassanein, A

    2014-11-04

    Tungsten has been chosen as the main candidate for plasma facing components (PFCs) due to its superior properties under extreme operating conditions in future nuclear fusion reactors such as ITER. One of the serious issues for PFCs is the high heat load during transient events such as ELMs and disruption in the reactor. Recrystallization and grain size growth in PFC materials caused by transients are undesirable changes in the material, since the isotropic microstructure developed after recrystallization exhibits a higher ductile-to-brittle transition temperature which increases with the grain size, a lower thermal shock fatigue resistance, a lower mechanical strength, and an increased surface roughening. The current work was focused on careful determination of the threshold parameters for surface recrystallization, grain growth rate, and thermal shock fatigue resistance under ELM-like transient heat events. Transient heat loads were simulated using long pulse laser beams for two different grades of ultrafine-grained tungsten. It was observed that cold rolled tungsten demonstrated better power handling capabilities and higher thermal stress fatigue resistance compared to severely deformed tungsten. Higher recrystallization threshold, slower grain growth, and lower degree of surface roughening were observed in the cold rolled tungsten.

  20. Impurity migration with RF sheath and ELMs perturbed electric field in tokamak

    NASA Astrophysics Data System (ADS)

    Gui, Bin; Xiao, Xiaotao; Tang, Tengfei; Xu, Xueqiao

    2016-10-01

    In radio frequency (RF) experiments, impurity generation and transport are important due to the phenomenon of RF enhanced impurity generation. In BOUT + + framework, the equilibrium radial electric field with RF sheath boundary condition on the limiter or the divertor surface is self-consistently calculated by using a two-field model. Based on this self-consistent calculation, it is found the positive radial electric field forms in the SOL region which qualitatively agrees with the experimental on the TEXTOR. The test particle module is developed in BOUT + + framework to simulate both turbulence and neoclassical physics in realistic geometry. Firstly, the drift orbit is calculated in cylinder coordinates due to singularity of x-point in flux coordinate. The turbulence transport of impurity generated from hot spot of RF limiter is simulated by random walk model. The numerical results show that less impurities will migrate into core and divertor region, more impurities migrate into nearby SOL boundary when turbulence transport enhanced. Then the effect of RF sheath potential on impurity migration will be simulated. Using the perturbed electric field from our BOUT + + nonlinear ELMs simulation, the transport of the impurities in different phase of ELMs are also discussed. USDOE by LLNL under DE-AC52-07NA27344.

  1. Adaptive phenotypic plasticity of Siberian elm in response to drought stress: increased stomatal pore depth.

    PubMed

    Park, Go Eun; Kim, Ki Woo; Lee, Don Koo; Hyun, Jung Oh

    2013-08-01

    Leaf stomatal characteristics of Siberian elm (Ulmus pumila) were investigated by electron microscopy and white light scanning interferometry. On the basis of average annual precipitations, two types of tree specimens were collected from Korea, China, and Mongolia: (1) trees under normal environmental conditions and (2) trees under arid conditions. Field emission scanning electron microscopy revealed oval-shaped stomata on the lower surface, and they were ca. 20 μm in width. In-lens secondary electron imaging showed differences in electron density and stomatal pore depth between the two types. According to the line profile analysis by white light scanning interferometry, stomata under arid conditions appeared to have higher levels of the stomatal pore depth than ones under normal conditions. Focused ion beam-field emission electron microscopy supported the increased stomatal pore depth with the increasing drought stress gradient. These results suggest that complementary microscopy can be employed to unravel the adaptive phenotypic plasticity of Siberian elm in response to drought stress.

  2. Design Of JET ELM Control Coils For Operation At 350 C

    SciTech Connect

    Zatz, I J; Brooks, A; Cole, M; Neilson, G H; Lowry, C; Mardenfeld, M; Omran, H; Thompson, V; Todd, T

    2010-09-20

    A study has confirmed the feasibility of designing, fabricating and installing resonant magnetic field perturbation (RMP) coils in JET1 with the objective of controlling edge localized modes (ELM). A system of two rows of in-vessel coils, above the machine midplane, has been chosen as it not only can investigate the physics of and achieve the empirical criteria for ELM suppression, but also permits variation of the spectra allowing for comparison with other experiments. These coils present several engineering challenges. Conditions in JET necessitate the installation of these coils via remote handling, which will impose weight, dimensional and logistical limitations. And while the encased coils are designed to be conventionally wound and bonded, they will not have the usual benefit of active cooling. Accordingly, coil temperatures are expected to reach 350 C during bakeout as well as during plasma operations. These elevated temperatures are beyond the safe operating limits of conventional OFHC copper and the epoxies that bond and insulate the turns of typical coils. This has necessitated the use of an alternative copper alloy conductor C18150 (CuCrZr). More importantly, an alternative to epoxy had to be found. An R&D program was initiated to find the best available insulating and bonding material. The search included polyimides and ceramic polymers. The scope and status of this R&D program, as well as the critical engineering issues encountered to date are reviewed and discussed.

  3. Pedestal shape, stability and inter-ELM evolution for different main ion species in ASDEX Upgrade

    NASA Astrophysics Data System (ADS)

    Laggner, Florian M.

    2016-10-01

    In tokamak plasmas with different main ion species as hydrogen isotopes or helium, a change of confinement occurs, known as isotope effect. To identify the processes defining the pedestal structure and evolution, experiments comparing hydrogen (H), deuterium (D) and helium (He) plasmas have been performed. Their goal was to match the pedestal top electron density and temperatures and compare the pedestal shape and stability. A factor of almost 10 higher gas puff as well as a factor of 2 higher heating power were required in H to achieve the same pedestal top values as in the D reference. While the pedestal electron temperature profiles do not differ, the density profile in H has shallower gradients. These can be explained by a lower particle confinement in H, if the ionization source profile is assumed to be similar. In He plasmas owing to the larger effective charge, the stored energy at similar pedestal top electron density is roughly a factor of 1.5 smaller than in the references, leading to the absence of ELMs. In summary the experimental results suggest different particle and energy confinement for different main ion species, however, peeling-ballooning theory can sufficiently describe the pedestal stability and ELM behavior. This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018 under Grant Agreement No. 633053.

  4. Aquifer test to determine hydraulic properties of the Elm aquifer near Aberdeen, South Dakota

    USGS Publications Warehouse

    Schaap, Bryan D.

    2000-01-01

    The Elm aquifer, which consists of sandy and gravelly glacial-outwash deposits, is present in several counties in northeastern South Dakota. An aquifer test was conducted northeast of Aberdeen during the fall of 1999 to determine the hydraulic properties of the Elm aquifer in that area. An improved understanding of the properties of the aquifer will be useful in the possible development of the aquifer as a water resource. Historical water-level data indicate that the saturated thickness of the Elm aquifer can change considerably over time. From September 1977 through November 1985, water levels at three wells completed in the Elm aquifer near the aquifer test site varied by 5.1 ft, 9.50 ft, and 11.1 ft. From June 1982 through October 1999, water levels at five wells completed in the Elm aquifer near the aquifer test site varied by 8.7 ft, 11.4 ft, 13.2 ft, 13.8 ft, and 19.7 ft. The water levels during the fall of 1999 were among the highest on record, so the aquifer test was affected by portions of the aquifer being saturated that might not be saturated during drier times. The aquifer test was conducted using five existing wells that had been installed prior to this study. Well A, the pumped well, has an operating irrigation pump and is centrally located among the wells. Wells B, C, D, and E are about 70 ft, 1,390 ft, 2,200 ft, and 3,100 ft, respectively, in different directions from Well A. Using vented pressure transducers and programmable data loggers, water-level data were collected at the five wells prior to, during, and after the pumping, which started on November 19, 1999, and continued a little over 72 hours. Based on available drilling logs, the Elm aquifer near the test area was assumed to be unconfined. The Neuman (1974) method theoretical response curves that most closely match the observed water-level changes at Wells A and B were calculated using software (AQTESOLV for Windows Version 2.13-Professional) developed by Glenn M. Duffield of Hydro

  5. METHANE PENTRATION IN DIII-D ELMing H-MODE PLASMAS

    SciTech Connect

    W.P. WEST; C.J. LASNIER; D.G. WHYTE; R.C. ISLER; T.E. EVANS; G.L. JACKSON; D.L. RUDAKOV; M.R. WADE; J. STRACHAN

    2002-06-01

    Carbon penetration into the core plasma during midplane and divertor methane puffing has been measured for DIII-D ELMing H-mode plasmas. The methane puffs are adjusted to a measurable signal, but global plasma parameters are only weakly affected (line average density, increases by < 10%, energy confinement time, {tau}{sub E} drops by < 10%). The total carbon content is derived from C{sup +6} density profiles in the core measured as a function of time using charge exchange recombination spectroscopy. The methane penetration factor is defined as the difference in the core content with the puff on and puff off, divided by the carbon confinement time and the methane puffing rate. In ELMing H-mode discharges with ion {del}B drift direction into the X-point, increasing the line averaged density from 5 to 8 x 10{sup 19} m{sup -3} dropped the penetration factor from 6.6% to 4.6% for main chamber puffing. The penetration factor for divertor puffing was below the detection limit (<1%). Changing the ion {del}B drift direction to away from the X-point decreased the penetration factor by more than a factor of five for main chamber puffing.

  6. Recrystallization and grain growth induced by ELMs-like transient heat loads in deformed tungsten samples

    PubMed Central

    Suslova, A.; El-Atwani, O.; Sagapuram, D.; Harilal, S. S.; Hassanein, A.

    2014-01-01

    Tungsten has been chosen as the main candidate for plasma facing components (PFCs) due to its superior properties under extreme operating conditions in future nuclear fusion reactors such as ITER. One of the serious issues for PFCs is the high heat load during transient events such as ELMs and disruption in the reactor. Recrystallization and grain size growth in PFC materials caused by transients are undesirable changes in the material, since the isotropic microstructure developed after recrystallization exhibits a higher ductile-to-brittle transition temperature which increases with the grain size, a lower thermal shock fatigue resistance, a lower mechanical strength, and an increased surface roughening. The current work was focused on careful determination of the threshold parameters for surface recrystallization, grain growth rate, and thermal shock fatigue resistance under ELM-like transient heat events. Transient heat loads were simulated using long pulse laser beams for two different grades of ultrafine-grained tungsten. It was observed that cold rolled tungsten demonstrated better power handling capabilities and higher thermal stress fatigue resistance compared to severely deformed tungsten. Higher recrystallization threshold, slower grain growth, and lower degree of surface roughening were observed in the cold rolled tungsten. PMID:25366885

  7. Role of plasma shape in access to ELM suppression at low collisionality: First observation of ELM suppression in ASDEX Upgrade in a shape-matching identity experiment with DIII-D

    NASA Astrophysics Data System (ADS)

    Suttrop, Wolfgang; Nazikian, Raffi; Kirk, Andrew; ASDEX Upgrade Team; Diii-D Team; Eurofusion Mst1 Team

    2016-10-01

    Controlled plasma shape scans at low pedestal collisionality νped* < 0.4 in DIII-D reveal that the threshold of magnetic perturbation field strength for suppression of edge-localized modes (ELMs) depends on both upper and lower plasma triangularity. Similar plasmas with matching shape and matching plasma parameters have been performed in DIII-D and ASDEX Upgrade. In these discharges, stationary ELM suppression by magnetic perturbations is observed for the first time in ASDEX Upgrade.Despite different divertor geometry and different first wall materials in the two machines, these plasmas show many similarities: Complete ELM suppression occurs in a narrow windows around q95 3.7 with transitions to phases with ``fuzzy'' ELMs outside these windows, electron density and temperature profiles as well as the total pedestal pressure are well matched, while there are variations of other quantities such as impurity concentrations and impurity rotation frequencies. A first experiment with injection of tungsten shows that the tungsten impurity content in the plasma decays on the time scale of energy confinement. see http://www.euro-fusionscipub.org/mst1.

  8. Slippery Elm

    MedlinePlus

    ... infections and inflammation, syphilis, herpes, and for expelling tapeworms. It is also used for protecting against stomach ... Diarrhea. Gout. Hemorrhoids. Herpes. Rheumatism. Stomach ulcers. Syphilis. Tapeworm. Toothache. Urinary tract infections. Other conditions. More evidence ...

  9. Effect of n = 3 perturbation field amplitudes below the ELM triggering threshold on edge and SOL transport in NSTX

    DOE PAGES

    J. M. Canik; Lore, J. D.; Ahn, J. -W.; ...

    2013-01-12

    Here, the pulsed application of n = 3 magnetic perturbation fields with amplitudes below that which triggers ELMs results in distinct, transient responses observable on several edge and divertor diagnostics in NSTX. We refer to these responses as Sub-Threshold Edge Perturbations (STEPs). An analysis of edge measurements suggests that STEPs result in increased transport in the plasma edge and scrape-off layer, which leads to augmentation of the intrinsic strike point splitting due to error fields, i.e., an intensification of the helical divertor footprint flux pattern. These effects are much smaller in magnitude than those of triggered ELMs, and are observedmore » for the duration of the field perturbation measured internal to the vacuum vessel. In addition, STEPs are correlated with changes to the MHD activity, along with transient reductions in the neutron production rate. Ideally the STEPs could be used to provide density control and prevent impurity accumulation, in the same manner that on-demand ELM triggering is used on NSTX, without the impulsive divertor fluxes and potential for damage to plasma facing components associated with ELMs.« less

  10. Description and phylogeny of a new microsporidium from the elm leaf beetle, Xanthogaleruca luteola Muller, 1766 (Coleoptera: Chrysomelidae)

    USDA-ARS?s Scientific Manuscript database

    This study describes a new genus and species of microsporidia which is a pathogen of the elm leaf beetle, Xanthogaleruca luteola Muller, 1776 (Coleoptera: Chrysomelidae). The beetles were collected from Istanbul in Turkey. All developmental stages are uninucleate and in direct contact with the host ...

  11. A computer aided diagnosis system for thyroid disease using extreme learning machine.

    PubMed

    Li, Li-Na; Ouyang, Ji-Hong; Chen, Hui-Ling; Liu, Da-You

    2012-10-01

    In this paper, we present an effective and efficient computer aided diagnosis (CAD) system based on principle component analysis (PCA) and extreme learning machine (ELM) to assist the task of thyroid disease diagnosis. The CAD system is comprised of three stages. Focusing on dimension reduction, the first stage applies PCA to construct the most discriminative new feature set. After then, the system switches to the second stage whose target is model construction. ELM classifier is explored to train an optimal predictive model whose parameters are optimized. As we known, the number of hidden neurons has an important role in the performance of ELM, so we propose an experimental method to hunt for the optimal value. Finally, the obtained optimal ELM model proceeds to perform the thyroid disease diagnosis tasks using the most discriminative new feature set and the optimal parameters. The effectiveness of the resultant CAD system (PCA-ELM) has been rigorously estimated on a thyroid disease dataset which is taken from UCI machine learning repository. We compare it with other related methods in terms of their classification accuracy. Experimental results demonstrate that PCA-ELM outperforms other ones reported so far by 10-fold cross-validation method, with the mean accuracy of 97.73% and with the maximum accuracy of 98.1%. Besides, PCA-ELM performs much faster than support vector machines (SVM) based CAD system. Consequently, the proposed method PCA-ELM can be considered as a new powerful tools for diagnosing thyroid disease with excellent performance and less time.

  12. Value Orientations of the Dutch Educational Elite.

    ERIC Educational Resources Information Center

    Karsten, Sjoerd; And Others

    1995-01-01

    Value orientations that influence opinions on educational policy issues were examined among Dutch leaders of educationally influential organizations. Their attitudes reflected Dutch society's segmentation along, but cooperation across, religious and ideological dividing lines, as well as optimism about educational reform through state…

  13. The Dutch surgical colorectal audit.

    PubMed

    Van Leersum, N J; Snijders, H S; Henneman, D; Kolfschoten, N E; Gooiker, G A; ten Berge, M G; Eddes, E H; Wouters, M W J M; Tollenaar, R A E M; Bemelman, W A; van Dam, R M; Elferink, M A; Karsten, Th M; van Krieken, J H J M; Lemmens, V E P P; Rutten, H J T; Manusama, E R; van de Velde, C J H; Meijerink, W J H J; Wiggers, Th; van der Harst, E; Dekker, J W T; Boerma, D

    2013-10-01

    In 2009, the nationwide Dutch Surgical Colorectal Audit (DSCA) was initiated by the Association of Surgeons of the Netherlands (ASN) to monitor, evaluate and improve colorectal cancer care. The DSCA is currently widely used as a blueprint for the initiation of other audits, coordinated by the Dutch Institute for Clinical Auditing (DICA). This article illustrates key elements of the DSCA and results of three years of auditing. Key elements include: a leading role of the professional association with integration of the audit in the national quality assurance policy; web-based registration by medical specialists; weekly updated online feedback to participants; annual external data verification with other data sources; improvement projects. In two years, all Dutch hospitals participated in the audit. Case-ascertainment was 92% in 2010 and 95% in 2011. External data verification by comparison with the Netherlands Cancer Registry (NCR) showed high concordance of data items. Within three years, guideline compliance for diagnostics, preoperative multidisciplinary meetings and standardised reporting increased; complication-, re-intervention and postoperative mortality rates decreased significantly. The success of the DSCA is the result of effective surgical collaboration. The leading role of the ASN in conducting the audit resulted in full participation of all colorectal surgeons in the Netherlands. By integrating the audit into the ASNs' quality assurance policy, it could be used to set national quality standards. Future challenges include reduction of administrative burden; expansion to a multidisciplinary registration; and addition of financial information and patient reported outcomes to the audit data. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. [Dutch parliament legitimizes harmful quackery].

    PubMed

    van Dam, Frits S A M; Renckens, Cees N M

    2010-01-01

    The Dutch parliament has recently accepted a tax law in which certain groups of alternative therapists can be exempt from VAT. To be eligible for this VAT exemption, the disciplines to which the therapists belong have to meet certain training requirements. In this article it is contended, in agreement with the Royal College of Physicians in the UK, that statutory regulation is inappropriate for disciplines whose therapies are neither of proved benefit nor appropriately tested. It legitimizes harmful therapies. This is illustrated by two serious accidents, previously described in this journal, caused by a chiropractor and a craniosacral therapist.

  15. Ophiostomatoid fungi associated with invasive Tetropium spp. (Fabr.) (Coleoptera:Cerambycidae) in Atlantic Canada.

    Treesearch

    Karin Jacobs; Keith A. Seifert; Ken J. Harrison; Georgette Smith; Thomas Kirisits

    2003-01-01

    Species of the Ascomycete genus Ophiostoma are well-known for causing stain in living trees and lumber, as well as devastating pathogens, for example O. ulmi and O. novo-ulmi, the causes of Dutch elm disease.

  16. Woodland Detection.

    ERIC Educational Resources Information Center

    Fischer, Richard B.

    1989-01-01

    Presents tips on nature observation during a woodland hike in the Adirondacks. Discusses engraver beetles and Dutch elm disease, birds' nests, hornets' nests, caterpillar webs, deer and bear signs, woodpecker holes, red squirrels, porcupine and beaver signs, and galls. (SV)

  17. Woodland Detection.

    ERIC Educational Resources Information Center

    Fischer, Richard B.

    1989-01-01

    Presents tips on nature observation during a woodland hike in the Adirondacks. Discusses engraver beetles and Dutch elm disease, birds' nests, hornets' nests, caterpillar webs, deer and bear signs, woodpecker holes, red squirrels, porcupine and beaver signs, and galls. (SV)

  18. Estimation of in-situ bioremediation system cost using a hybrid Extreme Learning Machine (ELM)-particle swarm optimization approach

    NASA Astrophysics Data System (ADS)

    Yadav, Basant; Ch, Sudheer; Mathur, Shashi; Adamowski, Jan

    2016-12-01

    In-situ bioremediation is the most common groundwater remediation procedure used for treating organically contaminated sites. A simulation-optimization approach, which incorporates a simulation model for groundwaterflow and transport processes within an optimization program, could help engineers in designing a remediation system that best satisfies management objectives as well as regulatory constraints. In-situ bioremediation is a highly complex, non-linear process and the modelling of such a complex system requires significant computational exertion. Soft computing techniques have a flexible mathematical structure which can generalize complex nonlinear processes. In in-situ bioremediation management, a physically-based model is used for the simulation and the simulated data is utilized by the optimization model to optimize the remediation cost. The recalling of simulator to satisfy the constraints is an extremely tedious and time consuming process and thus there is need for a simulator which can reduce the computational burden. This study presents a simulation-optimization approach to achieve an accurate and cost effective in-situ bioremediation system design for groundwater contaminated with BTEX (Benzene, Toluene, Ethylbenzene, and Xylenes) compounds. In this study, the Extreme Learning Machine (ELM) is used as a proxy simulator to replace BIOPLUME III for the simulation. The selection of ELM is done by a comparative analysis with Artificial Neural Network (ANN) and Support Vector Machine (SVM) as they were successfully used in previous studies of in-situ bioremediation system design. Further, a single-objective optimization problem is solved by a coupled Extreme Learning Machine (ELM)-Particle Swarm Optimization (PSO) technique to achieve the minimum cost for the in-situ bioremediation system design. The results indicate that ELM is a faster and more accurate proxy simulator than ANN and SVM. The total cost obtained by the ELM-PSO approach is held to a minimum

  19. Microsatellite markers for the critically endangered elm species Ulmus gaussenii (Ulmaceae).

    PubMed

    Geng, Qi-Fang; Yang, Jie; He, Jia; Wang, Dan-Bi; Shi, En; Xu, Wei-Xiang; Jeelani, Nasreen; Wang, Zhong-Sheng; Liu, Hong

    2016-07-20

    The Anhui elm Ulmus gaussenii is listed as a critically endangered species by the International Union for Conservation of Nature and is endemic to China, where its only population is restricted to Langya Mountain in Chuzhou, Anhui Province. To better understand the population genetics of U. gaussenii, we developed 12 microsatellite markers using an improved technique. The 12 markers were polymorphic, with the number of alleles per locus ranging from two to nine. Observed and expected heterozygosities ranged from 0.021 to 0.750 and 0.225 to 0.744, respectively. The inbreeding coefficient ranged from -0.157 to 0.960. Significant linkage disequilibrium was detected for two pairs of loci, and significant deviations from Hardy-Weinberg equilibrium were found in nine loci. These microsatellite markers will contribute to the studies of population genetics in U. gaussenii, which in turn will contribute to species conservation and protection.

  20. Quasilinear modelling of RMP interaction with a tokamak plasma: application to ASDEX Upgrade ELM mitigation experiments

    NASA Astrophysics Data System (ADS)

    Heyn, Martin F.; Ivanov, Ivan B.; Kasilov, Sergei V.; Kernbichler, Winfried; Leitner, Peter; Nemov, Viktor V.; Suttrop, Wolfgang; the ASDEX Upgrade Team

    2014-06-01

    First experiments on edge-localized mode (ELM) mitigation with the help of ITER-like coils on ASDEX Upgrade are analysed using linear and quasilinear kinetic models to describe the interaction of resonant magnetic field perturbations (RMP) with the plasma. The gyrokinetic derivation of RMP-driven transport coefficients is given in detail. The role of fluid resonances is studied, in particular the role of the resonance associated with the equilibrium electric field reversal point Er = 0. Like the electron fluid resonance associated with the zero of the total perpendicular electron fluid velocity, the Er = 0 resonance may lead to enhanced transport due to the reduction of RMP shielding in the pedestal region where the RMP field can even be amplified by this resonance. The conditions on the RMP coil spectrum resulting from the analysis are discussed.

  1. Surface damage of W exposed to combined stationary D plasma and ELMs-like pulsed plasma

    NASA Astrophysics Data System (ADS)

    Jia, Y. Z.; Liu, W.; Xu, B.; Qu, S. L.; Morgan, T. W.

    2017-04-01

    The surface damage of W under D plasma and ELMs-like transient heat loads was studied by combined stationary and pulsed D plasma. Low-flux transient heat loads will promote blister formation due to the gas expansion inside the blisters. On the contrary, high-flux transient heat loads will mitigate blistering due to the high surface temperature. Therefore, blistering on W surface first increased and then decreased with the increasing transient heat loads. The promotion effect of pulsed plasma on blistering is more obvious on [001] and [110] surfaces than on [111] surface, and the orientation dependence of blisters was mitigated by the transient heat loads. Surface modification induced by transient heat loads only formed on [001] and [110] surfaces, but did not form on [111] surface. The orientation dependence of surface modification was mainly due to the slipping system of dislocations.

  2. Surface damage characteristics of CFC and tungsten with repetitive ELM-like pulsed plasma irradiation

    NASA Astrophysics Data System (ADS)

    Kikuchi, Y.; Nishijima, D.; Nakatsuka, M.; Ando, K.; Higashi, T.; Ueno, Y.; Ishihara, M.; Shoda, K.; Nagata, M.; Kawai, T.; Ueda, Y.; Fukumoto, N.; Doerner, R. P.

    2011-08-01

    Surface damage of carbon fiber composite (CFC) and tungsten (W) due to repetitive ELM-like pulsed plasma irradiation has been investigated by using a magnetized coaxial plasma gun. CX2002U CFC and stress-relieved W samples were exposed to repetitive pulsed deuterium plasmas with duration of ˜0.5 ms, incident ion energy of ˜30 eV, and surface absorbed energy density of ˜0.3-0.7 MJ/m2. Bright spots on a CFC surface during pulsed plasma exposures were clearly observed with a high-speed camera, indicating a local surface heating. No melting of a W surface was observed under a single plasma pulse exposure at energy density of ˜0.7 MJ/m2, although cracks were formed. Cracking of the W surface grew with repetitive pulsed plasma exposures. Subsequently, the surface melted due to localized heat absorption.

  3. Effect of collisional temperature isotropisation on ELM parallel transport in a tokamak scrape-off layer

    NASA Astrophysics Data System (ADS)

    Coulette, David; Hirstoaga, Sever A.; Manfredi, Giovanni

    2016-08-01

    We develop a hybrid model to describe the parallel transport in a tokamak scrape-off layer following an edge-localized mode (ELM) event. The parallel dynamics is treated with a kinetic Vlasov-Poisson model, while the evolution of the perpendicular temperature {{T}\\bot} is governed by a fluid equation. The coupling is ensured by isotropising collisions. The model generalises an earlier approach where {{T}\\bot} was constant in space and time (Manfredi et al 2011 Plasma Phys. Control. Fusion 53 015012). Numerical results show that the main effect comes from electron-electron collisions, which limit the decrease of the parallel electron temperature and increase the potential drop in the Debye sheath in front of the surface. Ion-ion collisions have an almost negligible impact. The net effect is an increased peak power load on the target plates.

  4. Cold tolerance and supercooling capacity in overwintering adults of elm leaf beetle Xanthogaleruca luteola (Coleoptera: Chrysomelidae).

    PubMed

    Soudi, Sh; Moharramipour, S

    2011-12-01

    Elm leaf beetle, Xanthogaleruca luteola (Muller) is one of the key pests of elm trees all over the world, and survives winter in reproductive diapause in sheltered locations. Seasonal variation of whole body supercooling points (SCPs), LT50 (temperature at which 50% of the test individuals die) and survival rate after exposure to subzero temperatures were determined in field collected adults during October 2008 to May 2009 and October 2009 to May 2010. The SCP of adults decreased significantly from October (median=-13.8°C) to January (median=-20.7°C) in first year, relatively similar results was observed in the second year. The lowest LT50 was observed in overwintering adults collected in January (-16.81°C) in the first year and December (-15.59°C) in the second year. Mortality at -15°C for 24 h was >70% in early autumn in both years whereas it decreased to lower than 45% in early winter, the highest mortality (100%) was observed in adults collected in May in both years. Cold acclimated adults (30 d, 5°C) in November 2008 exhibited significantly higher SCP (-12.21±0.64°C) than nonacclimated adults (-15.57±1.35°C). A 30-d exposure to 5°C caused >20% mortality in November, while <9% mortality was observed in adults collected in December and January 2008. Overwintering adults died upon freezing and the lower lethal temperatures were within the range of SCP, indicating that X. luteola is a freeze intolerant insect.

  5. Influence of plasma pedestal profiles on access to ELM-free regimes in ITER

    SciTech Connect

    Medvedev, S. Yu. Ivanov, A. A. Martynov, A. A. Poshekhonov, Yu. Yu.; Konovalov, S. V.; Polevoi, A. R.

    2016-05-15

    The influence of current density and pressure gradient profiles in the pedestal on the access to the regimes free from edge localized modes (ELMs) like quiescent H-mode in ITER is investigated. Using the simulator of MHD modes localized near plasma boundary based on the KINX code, calculations of the ELM stability were performed for the ITER plasma in scenarios 2 and 4 under variations of density and temperature profiles with the self-consistent bootstrap current in the pedestal. Low pressure gradient values at the separatrix, the same position of the density and temperature pedestals and high poloidal beta values facilitate reaching high current density in the pedestal and a potential transition into the regime with saturated large scale kink modes. New version of the localized MHD mode simulator allows one to compute the growth rates of ideal peeling-ballooning modes with different toroidal mode numbers and to determine the stability region taking into account diamagnetic stabilization. The edge stability diagrams computations and sensitivity studies of the stability limits to the value of diamagnetic frequency show that diamagnetic stabilization of the modes with high toroidal mode numbers can help to access the quiescent H-mode even with high plasma density but only with low pressure gradient values at the separatrix. The limiting pressure at the top of the pedestal increases for higher plasma density. With flat density profile the access to the quiescent H-mode is closed even with diamagnetic stabilization taken into account, while toroidal mode numbers of the most unstable peeling-ballooning mode decrease from n = 10−40 to n = 3−20.

  6. ELM simulation experiments using transient heat and particle load produced by a magnetized coaxial plasma gun

    NASA Astrophysics Data System (ADS)

    Shoda, K.; Sakuma, I.; Iwamoto, D.; Kikuchi, Y.; Fukumoto, N.; Nagata, M.

    2011-10-01

    It is considered that thermal transient events such as type I edge-localized modes (ELMs) and disruptions will limit the lifetime of plasma-facing components (PFCs) in ITER. It is predicted that the heat load onto the PFCs during type I ELMs in ITER is 0.2-2MJ/m2 with pulse length of ~0.1-1ms. We have investigated interaction between transient heat and particle load and the PFCs by using a magnetized coaxial plasma gun (MCPG) at University of Hyogo. In the experiment, a pulsed plasma with duration of ~0.5ms, incident ion energy of ~30eV, and surface absorbed energy density of ~0.3-0.7MJ/m2 was produced by the MCPG. However, no melting occurred on a tungsten surface exposed to a single plasma pulse of ~0.7MJ/m2, while cracks clearly appeared at the edge part of the W surface. Thus, we have recently started to improve the performance of the MCPG in order to investigate melt layer dynamics of a tungsten surface such as vapor cloud formation. In the modified MCPG, the capacitor bank energy for the plasma discharge is increased from 24.5 kJ to 144 kJ. In the preliminary experiments, the plasmoid with duration of ~0.6 ms, incident ion energy of ~ 40 eV, and the surface absorbed energy density of ~2 MJ/m2 was successfully produced at the gun voltage of 6 kV.

  7. Nonlinear ELM simulations based on a nonideal peeling–ballooning model using the BOUT++ code

    DOE PAGES

    Xu, X. Q.; Dudson, B. D.; Snyder, P. B.; ...

    2011-09-23

    A minimum set of equations based on the peeling–ballooning (P–B) model with nonideal physics effects (diamagnetic drift, E × B drift, resistivity and anomalous electron viscosity) is found to simulate pedestal collapse when using the BOUT++ simulation code, developed in part from the original fluid edge code BOUT. Linear simulations of P–B modes find good agreement in growth rate and mode structure with ELITE calculations. The influence of the E × B drift, diamagnetic drift, resistivity, anomalous electron viscosity, ion viscosity and parallel thermal diffusivity on P–B modes is being studied; we find that (1) the diamagnetic drift and Emore » × B drift stabilize the P–B mode in a manner consistent with theoretical expectations; (2) resistivity destabilizes the P–B mode, leading to resistive P–B mode; (3) anomalous electron and parallel ion viscosities destabilize the P–B mode, leading to a viscous P–B mode; (4) perpendicular ion viscosity and parallel thermal diffusivity stabilize the P–B mode. With addition of the anomalous electron viscosity under the assumption that the anomalous kinematic electron viscosity is comparable to the anomalous electron perpendicular thermal diffusivity, or the Prandtl number is close to unity, it is found from nonlinear simulations using a realistic high Lundquist number that the pedestal collapse is limited to the edge region and the ELM size is about 5–10% of the pedestal stored energy. Furthermore, this is consistent with many observations of large ELMs. The estimated island size is consistent with the size of fast pedestal pressure collapse. In the stable α-zones of ideal P–B modes, nonlinear simulations of viscous ballooning modes or current-diffusive ballooning mode (CDBM) for ITER H-mode scenarios are presented.« less

  8. Nonlinear ELM simulations based on a nonideal peeling–ballooning model using the BOUT++ code

    SciTech Connect

    Xu, X. Q.; Dudson, B. D.; Snyder, P. B.; Umansky, M. V.; Wilson, H. R.; Casper, T.

    2011-09-23

    A minimum set of equations based on the peeling–ballooning (P–B) model with nonideal physics effects (diamagnetic drift, E × B drift, resistivity and anomalous electron viscosity) is found to simulate pedestal collapse when using the BOUT++ simulation code, developed in part from the original fluid edge code BOUT. Linear simulations of P–B modes find good agreement in growth rate and mode structure with ELITE calculations. The influence of the E × B drift, diamagnetic drift, resistivity, anomalous electron viscosity, ion viscosity and parallel thermal diffusivity on P–B modes is being studied; we find that (1) the diamagnetic drift and E × B drift stabilize the P–B mode in a manner consistent with theoretical expectations; (2) resistivity destabilizes the P–B mode, leading to resistive P–B mode; (3) anomalous electron and parallel ion viscosities destabilize the P–B mode, leading to a viscous P–B mode; (4) perpendicular ion viscosity and parallel thermal diffusivity stabilize the P–B mode. With addition of the anomalous electron viscosity under the assumption that the anomalous kinematic electron viscosity is comparable to the anomalous electron perpendicular thermal diffusivity, or the Prandtl number is close to unity, it is found from nonlinear simulations using a realistic high Lundquist number that the pedestal collapse is limited to the edge region and the ELM size is about 5–10% of the pedestal stored energy. Furthermore, this is consistent with many observations of large ELMs. The estimated island size is consistent with the size of fast pedestal pressure collapse. In the stable α-zones of ideal P–B modes, nonlinear simulations of viscous ballooning modes or current-diffusive ballooning mode (CDBM) for ITER H-mode scenarios are presented.

  9. Scrape-off Layer Current Model for Filament Structure Observed during Edge Localized Modes (ELMs) in the DIII-D Tokamak

    SciTech Connect

    Takahashi, Hironori; Fredrickson, E. D.; Schaffer, M. J.

    2008-04-15

    The plasma in tokamaks often exhibits a relaxation oscillation called the edge localized mode (ELM), which is generally attributed to MHD instability driven by strong gradients at the plasma boundary. It is shown here that field-aligned currents flowing just outside the boundary may also play a role in the ELM process. The poloidal perturbation magnetic field during ELMs in the DIII–D tokamak calculated from measured currents can reproduce prominent observed features, including a narrow magnetic structure at the outboard midplane similar to filaments observed earlier in DIII–D and NSTX.

  10. Dutch translation and cross-cultural adaptation of the PROMIS® physical function item bank and cognitive pre-test in Dutch arthritis patients

    PubMed Central

    2012-01-01

    Introduction Patient-reported physical function is an established outcome domain in clinical studies in rheumatology. To overcome the limitations of the current generation of questionnaires, the Patient-Reported Outcomes Measurement Information System (PROMIS®) project in the USA has developed calibrated item banks for measuring several domains of health status in people with a wide range of chronic diseases. The aim of this study was to translate and cross-culturally adapt the PROMIS physical function item bank to the Dutch language and to pretest it in a sample of patients with arthritis. Methods The items of the PROMIS physical function item bank were translated using rigorous forward-backward protocols and the translated version was subsequently cognitively pretested in a sample of Dutch patients with rheumatoid arthritis. Results Few issues were encountered in the forward-backward translation. Only 5 of the 124 items to be translated had to be rewritten because of culturally inappropriate content. Subsequent pretesting showed that overall, questions of the Dutch version were understood as they were intended, while only one item required rewriting. Conclusions Results suggest that the translated version of the PROMIS physical function item bank is semantically and conceptually equivalent to the original. Future work will be directed at creating a Dutch-Flemish final version of the item bank to be used in research with Dutch speaking populations. PMID:22390734

  11. Ultrastructure of cells of Ulmus americana cultured in vitro and exposed to the culture filtrate of Ceratocystis ulmi

    Treesearch

    Paula M. Pijut; R. Daniel Lineberger; Subhash C. Domir; Jann M. Ichida; Charles R. Krause

    1990-01-01

    Calli of American elm susceptible and resistant to Dutch elm disease were exposed to a culture filtrate of a pathogenic isolate of Ceratocystis ulmi. Cells from untreated tissue exhibited typical internal composition associated with healthy, actively growing cells. All cells exposed to culture filtrate showed appreciable ultrastructural changes....

  12. A review of a new Dutch guideline for management of recurrent varicose veins.

    PubMed

    Lawson, James A; Toonder, Irwin M

    2016-03-01

    In 2013, the new Dutch guideline for "Venous Pathology" was published. The guideline was a revision and update from the guideline "Diagnostics and Treatment of Varicose Veins" from 2009 and the guideline "Venous Ulcer" from 2005. A guideline for "Deep Venous Pathology" and one for "Compression Therapy" was added to the overall guideline "Venous Pathology." The chapter about treatment of recurrent varicose veins after initial intervention was recently updated in 2015 and is reviewed here. The Dutch term "recidief varices" or the French "récidive de varices" should be used analogous to the English term "recurrent varicose veins." The DCOP Guideline Development Group Neovarices concluded that "recidief" in Dutch actually suggests recurrence after apparent successful treatment and ignores the natural progression of venous disease in its own right. So the group opted to use the term "neovarices." In the Dutch guideline, neovarices is meant to be an all embracing term for recurrent varicose veins caused by technical or tactical failure, evolvement from residual refluxing veins or natural progression of varicose vein disease at different locations of the treated leg after intervention. This report reviews the most important issues in the treatment of varicose vein recurrence, and discusses conclusions and recommendations of the Dutch Neovarices Guideline Committee. © The Author(s) 2016.

  13. [Teledermatology within Dutch nursing homes].

    PubMed

    Lubeek, Satish F K; Mommers, Roland J M; van der Geer, Eric R; van de Kerkhof, Peter C M; Gerritsen, Marie-Jeanne Rianne P

    2016-06-01

    Skin problems are common within the nursing home population and could have a significant impact on quality of life. As a form of long-distance consultation teledermatology offers several potential benefits within this frail population. In this review we discuss several aspects of teledermatology, especially in relation to the nursing home population. Several studies demonstrated that teledermatology is a cost-effective and easy-to-use consultation method, which could significantly reduce the amount of hospital visits. However, teledermatology is only used in a limited number of Dutch nursing homes in daily practice due to several factors. For the optimal implementation of teledermatological consultation there are some important logistical, legal and financial framework conditions. In conclusion, teledermatology has a lot to offer within the nursing home population and therefore teledermatology will hopefully be increasingly used in daily practice within the near future.

  14. Validation of the model for ELM suppression with 3D magnetic fields using low torque ITER baseline scenario discharges in DIII-D

    DOE PAGES

    Moyer, Richard A.; Paz-Soldan, Carlos; Nazikian, Raffi; ...

    2017-09-18

    Here, experiments have been executed in the DIII-D tokamak to extend suppression of Edge Localized Modes (ELMs) with Resonant Magnetic Perturbations (RMPs) to ITER-relevant levels of beam torque. The results support the hypothesis for RMP ELM suppression based on transition from an ideal screened response to a tearing response at a resonant surface that prevents expansion of the pedestal to an unstable width.

  15. Management Development from a Dutch Perspective.

    ERIC Educational Resources Information Center

    Paauwe, Jaap, Ed.; Williams, Roger, Ed.

    2001-01-01

    Includes "Seven Key Issues for Management Development" (Paauwe, Williams); "Typology of Management Development" (Jansen, van der Velde, Mul); "Management Development at Royal Dutch/Shell" (Mahieu); "Management Development in Unilever" (Reitsma); "International Co-ordination and Management…

  16. Development concept for Dutch user support

    NASA Astrophysics Data System (ADS)

    Pronk, C. N. A.; Koopman, N.; Dehoop, D.

    1992-06-01

    The main development approaches and some technologies developed in support of the different objectives of the Dutch Utilization Center (DUC) are reported. The DUC acts as a point of coordination of Dutch user support activities. The support needs of the user are analyzed and from there the required support efforts of the entities in the Dutch User Support Organization (DUSO) are activated. The main objectives of the DUSO are to promote the availability of the Columbus Space Station infrastructure among potential Dutch users, and to assist the users during the process of experiment definition, development, execution, and results evaluation. The DUSO support activities cover promotion and familiarization, and administrative, scientific, technical, and operational support to microgravity and space experimentation. The DUC developmental approaches consist of two approaches: a top down or formal approach; and a bottom up approach.

  17. Dutch research reforms cause a stir

    NASA Astrophysics Data System (ADS)

    van Calmthout, Martijn

    2015-02-01

    All 69 winners of the Spinoza prize - the highest award in Dutch science - have signed a petition against proposed reforms to the country's leading funding agency, the Netherlands Organisation for Scientific Research (NWO).

  18. Investigation of inter-ELM ion heat transport in the H-mode pedestal of ASDEX Upgrade plasmas

    NASA Astrophysics Data System (ADS)

    Viezzer, E.; Fable, E.; Cavedon, M.; Angioni, C.; Dux, R.; Laggner, F. M.; Bernert, M.; Burckhart, A.; McDermott, R. M.; Pütterich, T.; Ryter, F.; Willensdorfer, M.; Wolfrum, E.; the ASDEX Upgrade Team; the EUROfusion MST1 Team

    2017-02-01

    The ion heat transport in the pedestal of H-mode plasmas is investigated in various H-mode discharges with different pedestal ion collisionalities. Interpretive modelling suggests that in all analyzed discharges the ion heat diffusivity coefficient, {χ\\text{i}} , in the pedestal is close to the neoclassical prediction within the experimental uncertainties. The impact of changing the deposition location of the electron cyclotron resonance heating on the ion heat transport has been studied. The effect on the background profiles is small. The pre-ELM (edge localized modes) edge profiles as well as the behaviour of the electron temperature and density, ion temperature and impurity toroidal rotation during the ELM cycle are very similar in discharges with on- and off-axis ECRH heating. No significant deviation of {χ\\text{i}} from neoclassics is observed when changing the ECRH deposition location to the plasma edge.

  19. Estimation of the dust production rate from the tungsten armour after repetitive ELM-like heat loads

    NASA Astrophysics Data System (ADS)

    Pestchanyi, S.; Garkusha, I.; Makhlaj, V.; Landman, I.

    2011-12-01

    Experimental simulations for the erosion rate of tungsten targets under ITER edge-localized mode (ELM)-like surface heat loads of 0.75 MJ m-2 causing surface melting and of 0.45 MJ m-2 without melting have been performed in the QSPA-Kh50 plasma accelerator. Analytical considerations allow us to conclude that for both energy deposition values the erosion mechanism is solid dust ejection during surface cracking under the action of thermo-stress. Tungsten influx into the ITER containment of NW~5×1018 W per medium size ELM of 0.75 MJ m-2 and 0.25 ms time duration has been estimated. The radiation cooling power of Prad=150-300 MW due to such influx of tungsten is intolerable: it should cool the ITER core to 1 keV within a few seconds.

  20. sdA in SDSS DR12 are Overwhelmingly Not Extremely Low-Mass (ELM) White Dwarfs

    NASA Astrophysics Data System (ADS)

    Hermes, J. J.; Gänsicke, B. T.; Breedt, E.

    2017-03-01

    In a search for new white dwarfs in DR12 of the Sloan Digital Sky Survey, Kepler et al. 2016 found atmospheric parameters for thousands of objects with effective temperatures below 20,000 K and surface gravities between 5.5 < log g < 6.5. They classified these objects as cool subdwarfs – sdA – and speculated that many may be extremely low-mass (ELM) white dwarfs (helium-core white dwarfs with masses below 0.3 M⊙). We present evidence – using radial velocities, photometric colors, and reduced proper motions – that the vast majority (>99%) of these objects are unlikely to be ELM white dwarfs. Their true identity remains an interesting question.