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Sample records for high-level tellurite resistance

  1. Proteomic differences between tellurite-sensitive and tellurite-resistant E.coli.

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    Jana Aradská

    Full Text Available Tellurite containing compounds are in use for industrial processes and increasing delivery into the environment generates specific pollution that may well result in contamination and subsequent potential adverse effects on public health. It was the aim of the current study to reveal mechanism of toxicity in tellurite-sensitive and tellurite-resistant E. coli at the protein level. In this work an approach using gel-based mass spectrometrical analysis to identify a differential protein profile related to tellurite toxicity was used and the mechanism of ter operon-mediated tellurite resistance was addressed. E. coli BL21 was genetically manipulated for tellurite-resistance by the introduction of the resistance-conferring ter genes on the pLK18 plasmid. Potassium tellurite was added to cultures in order to obtain a final 3.9 micromolar concentration. Proteins from tellurite-sensitive and tellurite-resistant E. coli were run on 2-D gel electrophoresis, spots of interest were picked, in-gel digested and subsequently analysed by nano-LC-MS/MS (ion trap. In addition, Western blotting and measurement of enzymatic activity were performed to verify the expression of certain candidate proteins. Following exposure to tellurite, in contrast to tellurite-resistant bacteria, sensitive cells exhibited increased levels of antioxidant enzymes superoxide dismutases, catalase and oxidoreductase YqhD. Cysteine desulfurase, known to be related to tellurite toxicity as well as proteins involved in protein folding: GroEL, DnaK and EF-Tu were upregulated in sensitive cells. In resistant bacteria, several isoforms of four essential Ter proteins were observed and following tellurite treatment the abovementioned protein levels did not show any significant proteome changes as compared to the sensitive control. The absence of general defense mechanisms against tellurite toxicity in resistant bacteria thus provides further evidence that the four proteins of the ter operon

  2. Tellurite resistance and reduction by a Paenibacillus sp. isolated from heavy metal-contaminated sediment.

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    Chien, Chih-Ching; Han, Chu-Ting

    2009-08-01

    A gram-positive bacterium (designated as strain TeW) that is highly resistant to tellurite was isolated from sediment. The bacterium can grow in the presence of up to 2,000 micromol/L of potassium tellurite (K2TeO3). Reduction of K2TeO3 to tellurium was indicated by the blackening of the growth medium. No lag in growth was observed when cells unexposed to tellurite were transferred to the growth medium containing K2TeO3, indicating that resistance to tellurite was not inducible. Up to 50 and 90% of the metalloid oxyanion tellurite (TeO(3)(2-)) was removed from the medium by strain TeW during growth in nonstatic (shaking) and static (without shaking) conditions, respectively. The bacterium was identified as a Paenibacillus sp. according to its morphology, physiology, and 16S rDNA sequence homology.

  3. Determination of Abundance of Tellurite-Resistant Bacteria and the Ability of Remove of them from Qom Province Industrial Wastewater, Qom, Iran

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    Mahboubeh Soleimani Sasani

    2013-02-01

    Full Text Available Background and Objectives: Accumulation of toxic oxyanion of potassium tellurite, which has increased in the environment due to industrial activities, can cause complications in human, such as skin irritation, dermatitis, anorexia, tremor, nausea, vomiting, nervous system stimulation, convulsion, and respiratory arrest. The purpose of this research was to isolate tellurite-resistant bacteria, determine the minimum inhibitory concentration (MIC, and evaluate bioreduction of tellurite in strains.Methods: MIC was measured by agar dilution method in 84 resistant strains isolated from wastewater. QWTm6 strain with tolerance of tellurite concentration of 6684μg/ml was selected as superior strain. Toleration of this level of tellurite has not been reported yet. Results: According to biochemical, phenotypic, and physiological characteristics, QWTm6 was initially classified into Staphylococcus genus. Using the spectrophotometric technique and DDTC reagent (A340nm & sodium diethyldithiocarbamate trihydrate, maximum elimination was seen in 0.4mM concentration of potassium tellurite in 24 hours. The strain showed high ability in the elimination of toxic oxyanion of potassium tellurite under a wide range of factors such as pH=(5-11, temperature (15-50◦C, blender speed (50, 100, 150, and 200rpm, various oxyanion concentrations (0.04-1mM, and different percentages of NaCl (0-20%. This strain was also resistant to penicillin, cefixime, tetracycline, chloramphenicol, streptomycin, neomycin, erythromycin, gentamicin, kanamycin, norfloxacin, and ciprofloxacin.Conclusion: The results of this study showed that QWTm6 could be introduced in the international societies as an acceptable candidate for bioremediation, because of its high ability in removal and reduction of potassium tellurite.

  4. Biological synthesis of fluorescent nanoparticles by cadmium and tellurite resistant Antarctic bacteria: exploring novel natural nanofactories.

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    Plaza, D O; Gallardo, C; Straub, Y D; Bravo, D; Pérez-Donoso, J M

    2016-05-06

    Fluorescent nanoparticles or quantum dots (QDs) have been intensely studied for basic and applied research due to their unique size-dependent properties. There is an increasing interest in developing ecofriendly methods to synthesize these nanoparticles since they improve biocompatibility and avoid the generation of toxic byproducts. The use of biological systems, particularly prokaryotes, has emerged as a promising alternative. Recent studies indicate that QDs biosynthesis is related to factors such as cellular redox status and antioxidant defenses. Based on this, the mixture of extreme conditions of Antarctica would allow the development of natural QDs producing bacteria. In this study we isolated and characterized cadmium and tellurite resistant Antarctic bacteria capable of synthesizing CdS and CdTe QDs when exposed to these oxidizing heavy metals. A time dependent change in fluorescence emission color, moving from green to red, was determined on bacterial cells exposed to metals. Biosynthesis was observed in cells grown at different temperatures and high metal concentrations. Electron microscopy analysis of treated cells revealed nanometric electron-dense elements and structures resembling membrane vesicles mostly associated to periplasmic space. Purified biosynthesized QDs displayed broad absorption and emission spectra characteristic of biogenic Cd nanoparticles. Our work presents a novel and simple biological approach to produce QDs at room temperature by using heavy metal resistant Antarctic bacteria, highlighting the unique properties of these microorganisms as potent natural producers of nano-scale materials and promising candidates for bioremediation purposes.

  5. Incidence of high-level gentamicin resistance in enterococci at ...

    African Journals Online (AJOL)

    enterococcaJ isolates. Results. The incidence of HLGR was 26.5% of. Enterococcus faecaJis isolates and 20% of E. faecium isolates grown during the study period. Conclusions. High-level gentamicin resistance is common among enterococci isolated at Johannesburg. Hospital, and this observation must be considered in.

  6. Incidence of high-level gentamicin resistance in enterococci at ...

    African Journals Online (AJOL)

    The incidence of HLGR was 26.5% of Enterococcus faecaJis isolates and 20% of E. faecium isolates grown during the study period. Conclusions. High-level gentamicin resistance is common among enterococci isolated at Johannesburg Hospital, and this observation must be considered in defining strategies for the ...

  7. Tellurite resistance profiles and performance of different chromogenic agars for detection of non-O157 Shiga toxin-producing Escherichia coli.

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    Fan, Ruyue; Bai, Xiangning; Fu, Shanshan; Xu, Yanmei; Sun, Hui; Wang, Hong; Xiong, Yanwen

    2018-02-02

    Shiga toxin-producing Escherichia coli (STEC) are globally important food-borne pathogens. The isolation of non-O157 STEC is a significant public health challenge due to the dramatic diversity of their phenotypes and genotypes. In the present study, 476 non-O157 STEC strains representing 95 different O-serogroups were used to evaluate tellurite resistance and the performance of 12 different chromogenic agars. Of 476 strains, only 108 (22.7%) strains showed the minimal inhibitory concentration (MIC) values for potassium tellurite being higher than 4μg/ml, and 96 (20.2%) strains harbored intact ter genes cluster. The presence of ter genes was significantly correlated with tellurite resistance. Six commercial chromogenic agars (TBX, MAC, SMAC, Rainbow® Agar O157, CHROMagar™ ECC, and Fluorocult O157) supported the growth of all strains. However, CT-SMAC, CHROMagar™ O157, and CHROMagar™ STEC agars exhibited 12.2%, 31.1%, and 38.0% of growth inhibition, respectively. Furthermore, 4.6%, 33.2%, and 45.0% of strains were inhibited on RBA-USDA, RBA-NT, and BCM O157 agar media. Variations in tellurite resistance and colony appearance might result in discrepant performance of non-O157 STEC recovery from different chromogenic agars. Using inclusive agars or less selective agar in combination with highly selective agar should be suggested to recover most non-O157 STEC strains, which would increase the probability of recovering STECs from complex background microflora. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. The Rapid Emergence of High Level Gentamicin Resistance in Enterococci

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    Kevin R Forward

    1990-01-01

    Full Text Available The proportion of enterococci isolated from blood and urine cultures that were highly resistant to gentamicin and streptomycin were determined. No blood or urine isolates highly resistant to gentamicin were seen in 1983, whereas by 1986–87 25% of blood and 17% of urine isolates were highly resistant. The rapid emergence of gentamicin resistance has serious implications for patients with life threatening enterococcal disease.

  9. The Rapid Emergence of High Level Gentamicin Resistance in Enterococci

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    Forward, Kevin R; Kennedy, James K; Degagne, Patricia A; Bartlett, Kathy R; Harding, Godfrey KM

    1990-01-01

    The proportion of enterococci isolated from blood and urine cultures that were highly resistant to gentamicin and streptomycin were determined. No blood or urine isolates highly resistant to gentamicin were seen in 1983, whereas by 1986–87 25% of blood and 17% of urine isolates were highly resistant. The rapid emergence of gentamicin resistance has serious implications for patients with life threatening enterococcal disease.

  10. High level antibiotic resistance and relatedness of Staphylococcus ...

    African Journals Online (AJOL)

    Antibiotic resistant pattern show significant 100% resistance of S. aureus strains to Tetracycline, Penicillin and 50% to Amoxicillin while 100% and 92.9% show MIC > 16ug/ml to Amoxicillin, Tetracycline and Penicillin respectively. Similarly, 100% resistance to Tetracycline and Penicillin was shown by the S. aureus obtained ...

  11. Depletion of reduction potential and key energy generation metabolic enzymes underlies tellurite toxicity in Deinococcus radiodurans.

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    Anaganti, Narasimha; Basu, Bhakti; Gupta, Alka; Joseph, Daisy; Apte, Shree Kumar

    2015-01-01

    Oxidative stress resistant Deinococcus radiodurans surprisingly exhibited moderate sensitivity to tellurite induced oxidative stress (LD50 = 40 μM tellurite, 40 min exposure). The organism reduced 70% of 40 μM potassium tellurite within 5 h. Tellurite exposure significantly modulated cellular redox status. The level of ROS and protein carbonyl contents increased while the cellular reduction potential substantially decreased following tellurite exposure. Cellular thiols levels initially increased (within 30 min) of tellurite exposure but decreased at later time points. At proteome level, tellurite resistance proteins (TerB and TerD), tellurite reducing enzymes (pyruvate dehydrogense subunits E1 and E3), ROS detoxification enzymes (superoxide dismutase and thioredoxin reductase), and protein folding chaperones (DnaK, EF-Ts, and PPIase) displayed increased abundance in tellurite-stressed cells. However, remarkably decreased levels of key metabolic enzymes (aconitase, transketolase, 3-hydroxy acyl-CoA dehydrogenase, acyl-CoA dehydrogenase, electron transfer flavoprotein alpha, and beta) involved in carbon and energy metabolism were observed upon tellurite stress. The results demonstrate that depletion of reduction potential in intensive tellurite reduction with impaired energy metabolism lead to tellurite toxicity in D. radiodurans. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Enhancing the antibiotic antibacterial effect by sub lethal tellurite concentrations: tellurite and cefotaxime act synergistically in Escherichia coli.

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    Roberto C Molina-Quiroz

    Full Text Available The emergence of antibiotic-resistant pathogenic bacteria during the last decades has become a public health concern worldwide. Aiming to explore new alternatives to treat antibiotic-resistant bacteria and given that the tellurium oxyanion tellurite is highly toxic for most microorganisms, we evaluated the ability of sub lethal tellurite concentrations to strengthen the effect of several antibiotics. Tellurite, at nM or µM concentrations, increased importantly the toxicity of defined antibacterials. This was observed with both gram negative and gram positive bacteria, irrespective of the antibiotic or tellurite tolerance of the particular microorganism. The tellurite-mediated antibiotic-potentiating effect occurs in laboratory and clinical, uropathogenic Escherichia coli, especially with antibiotics disturbing the cell wall (ampicillin, cefotaxime or protein synthesis (tetracycline, chloramphenicol, gentamicin. In particular, the effect of tellurite on the activity of the clinically-relevant, third-generation cephalosporin (cefotaxime, was evaluated. Cell viability assays showed that tellurite and cefotaxime act synergistically against E. coli. In conclusion, using tellurite like an adjuvant could be of great help to cope with several multi-resistant pathogens.

  13. OCCURRENCE OF HIGH-LEVEL AMINOGLYCOSIDE RESISTANCE IN ENVIRONMENTAL ISOLATES OF ENTEROCOCCI

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    High-level resistance fo aminoglycosides was observed in environmental isolates of enterococci. Various aquatic habitats, including agricultural runoff, creeks, rivers, wastewater, and wells, were analyzed. Strains of Enterococcus faecalis, e.faecium, E. gallinarum, and other Ent...

  14. Incidence of high-level evernimicin resistance in Enterococcus faecium among food animals and humans

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller; McNicholas, P. M.

    2002-01-01

    Six high-level evernimicin-resistant Enterococcus faecium isolates were identified among 304 avilarnycin-resistant E. faecium isolates from animals and 404 stool samples from humans with diarrhea. All four animal isolates, and one of the human isolates, were able to transfer resistance...... to a susceptible E. faecium strain. The resulting transconjugants all tested positive for the presence of emtA, a gene encoding a methyltransferase previously linked with high-level evernimicin resistance. The four transconjugants derived from animal isolates all carried the same plasmid, while a differently sized...... plasmid was found in the isolate from humans. This study demonstrated a low incidence of high-level evernimicin resistance mediated by the emtA gene in different E. faecium isolates of animal and human origin....

  15. Pseudomonas aeruginosa develops Ciprofloxacin resistance from low to high level with distinctive proteome changes.

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    Peng, Jianhe; Cao, Jing; Ng, Fui Mee; Hill, Jeffrey

    2017-01-30

    Pseudomonas aeruginosa infection is difficult to treat because of its drug resistance, but how it develops drug resistance remains largely unknown. In this study we investigated Ciprofloxacin resistance development in P. aeruginosa. Different Ciprofloxacin concentrations selected different low level resistant mutants, and high level resistant mutants emerged from low level resistant mutants if stressed further by Ciprofloxacin. A deep quantitative proteomic study of the Ciprofloxacin resistant mutants uncovered the cellular pathways that supported such resistances. The two low level resistant mutants had different molecular mechanisms. One was mainly due to switching to anaerobic respiration and overexpression of catalase and peroxidase, and the other was probably due to iron and polyamine uptake and DNA repair. High level of resistance involved the mexCD-oprJ efflux pump and the downregulation of PQS quorum sensing. Other pathways might also have contributed to high level resistance, like the arginine deiminase pathway, catalase, peroxidase, protein degradation and DNA repair. The intracellular Ciprofloxacin concentration assay indicated that only the mexCD-oprJ overexpressed mutants had low drug accumulation. This study provided a comprehensive overview of the proteomic landscape in the evolution of Ciprofloxacin resistance in P. aeruginosa, and might have implications in diagnosis and treatment of Ciprofloxacin resistant P. aeruginosa. Data are available via ProteomeXchange with identifier PXD004560. Pseudomonas aeruginosa infection is difficult to treat because of its drug resistance, but how it develops drug resistance remains largely unknown. In this study we investigated Ciprofloxacin resistance development in P. aeruginosa. We found that Ciprofloxacin resistance developed from low to high level. Two different low levels resistant molecular mechanisms were discovered from different mutants selected by different Ciprofloxacin concentrations, one was mainly

  16. Tn924, a chromosome-borne transposon encoding high-level gentamicin resistance in Enterococcus faecalis.

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    Thal, L A; Chow, J W; Clewell, D B; Zervos, M J

    1994-01-01

    Enterococcus faecalis SF350 is a clinical isolate from Winnipeg, Canada, with high-level (MIC > 2,000 micrograms/ml) gentamicin resistance. The genetic determinant for gentamicin resistance was located on the chromosome of SF350 and could be mobilized by a coresident conjugative plasmid, pYN120. Genetic and physical analyses showed that the gentamicin resistance determinant was located on a 27-kb transposable element which was designated Tn924.

  17. MupB, a new high-level mupirocin resistance mechanism in Staphylococcus aureus.

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    Seah, Christine; Alexander, David C; Louie, Lisa; Simor, Andrew; Low, Donald E; Longtin, Jean; Melano, Roberto G

    2012-04-01

    Mupirocin is a topical antibiotic used for the treatment of skin infections and the eradication of methicillin-resistant Staphylococcus aureus carriage. It inhibits bacterial protein synthesis by interfering with isoleucyl-tRNA synthetase activity. High-level mupirocin resistance (MIC of ≥ 512 μg/ml) is mediated by the expression of mupA (ileS2), which encodes an alternate isoleucyl-tRNA synthetase. In this study, we describe high-level mupirocin resistance mediated by a novel locus, mupB. The mupB gene (3,102 bp) shares 65.5% sequence identity with mupA but only 45.5% identity with ileS. The deduced MupB protein shares 58.1% identity (72.3% similarity) and 25.4% identity (41.8% similarity) with MupA and IleS, respectively. Despite this limited homology, MupB contains conserved motifs found in class I tRNA synthetases. Attempts to transfer high-level mupirocin resistance via conjugation or transformation (using plasmid extracts from an mupB-containing strain) were unsuccessful. However, by cloning the mupB gene into a shuttle vector, it was possible to transfer the resistance phenotype to susceptible S. aureus by electroporation, proving that mupB was responsible for the high-level mupirocin resistance. Further studies need to be done to determine the prevalence of mupB and to understand risk factors and outcomes associated with resistance mediated by this gene.

  18. [Genotypes of aminoglycoside-modifying enzyme and clinical study of high-level gentamycin resistant enterococcus].

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    Qu, Ting-ting; Zhang, Ying; Yu, Yun-song; Chen, Ya-gang; Wei, Ze-qing; Li, Lan-juan

    2006-01-01

    To determine the antibiotics resistance, aminoglycoside-modifying enzymes and homology of high-level gentamycin resistant enterococcus in clinical specimens. The high-level gentamicin resistant (HLGR) isolates were screened by the agar method and the resistance of 14 antimicrobial agents was determined by K-B method. The aminoglycoside-modifying enzyme genes were detected by polymerase chain reaction (PCR). Pulsed-field gel electrophoresis (PFGE) was used to analyze the homology of HLGR isolates. The ratio of HLGR was 64.2% (68/106). Among the HLGR,there were no isolates resistant to linezolid, vancomycin and tecoplanin, and Enterococcus faecium was more resistant to beta-lactam antibiotics and quinolone than Enterococcus faecalis. The positive rate of aac(6')-Ie-aph(2')-Ia was 92.6% and 3 isolates had the resistance gene mostly similar to aph(2')-Id. And among 51 HLGR isolates from the hospitalized patients, PFGE grouped 17 E. faecalis isolates into 4 clusters (A-D), and 33 E. faecium isolates into 8 clusters (A-H) with A cluster as predominant. HLGR has become the important antibiotic resistance bacteria which results in nosocomial infection; and aac(6')-Ie-aph(2')-Ia is the main aminoglycoside-modifying enzyme gene which causes HLGR.

  19. High Levels of Resistance in the Common Bed Bug, Cimex lectularius (Hemiptera: Cimicidae), to Neonicotinoid Insecticides.

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    Romero, Alvaro; Anderson, Troy D

    2016-05-01

    The rapid increase of bed bug populations resistant to pyrethroids demands the development of novel control tactics. Products combining pyrethroids and neonicotinoids have become very popular for bed bug control in the United States, but there are concerns about evolution of resistance to these compounds. Laboratory assays were used to measure the toxicity of topical applications of four neonicotinoids to a susceptible population and three pyrethroid-resistant populations. Activity of esterases, glutathione S-transferases, and cytochrome P450s of all strains was also evaluated. High levels of resistance to four neonicotinoids, acetamiprid, imidacloprid, dinotefuran, and thiamethoxam, relative to the susceptible Fort Dix population, were detected in populations collected from human dwellings in Cincinnati and Michigan. Because activity of detoxifying enzymes was increased in these two populations, our results suggest that these enzymes have some involvement in neonicotinoid resistance, but other resistance mechanisms might be involved as well. Detection of high levels of resistance to neonicotinoids further limits the options for chemical control of bed bugs. Published by Oxford University Press on behalf of Entomological Society of America 2016. This work is written by US Government employees and is in the public domain in the US.

  20. High-level resistance to aminoglycoside, vancomycin, and linezolid in enterococci strains

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    Gülçin Baldır

    2013-09-01

    Full Text Available Objective: This study aimed to identify antibiotic susceptibility rates of enterococcal strains, and to compare the highlevelresistance to aminoglycosides (HLAR in vancomycin-sensitive enterococcal species (VSE and vancomycin-resistantenterococcal species (VRE.Methods: The study included 100 VRE and 100 VSE strains recovered from the samples sent to laboratory from variousdepartments of Haydarpaşa Numune Training and Research Hospital.Results: All VRE strains were defined as Enterococcus faecium, although of the VSE strains, 53% were identified to beas Enterococcus faecalis, 42% E. faecium, 3% Enterococcus durans, and 2% Enterococcus avium. High-level resistance tovancomycin (MIC, >256 μg/ml was determined in all VRE strains and when analyzing MIC values for teicoplanin, fivestrains were found to be moderately susceptible (MIC, 16 μg/ml and 95 strains were resistant (MIC, >32 μg/ml. Of theVRE strains, one was linezolid-resistant (MIC, 12 μg/ml and the other was intermediately susceptible (MIC, 4 μg/ml andremainders were evaluated to be susceptible (MIC, <2 μg/ml. In VRE strains, high-level gentamicin resistance (HLGRwas found to be 83% and high-level streptomycin resistance (HLSR 89%, association of HLSR with HLGR was 78%. InVSE strains, HLGR was found to be 42% and, HLSR 48%, the association of HLSR with HLGR was found to be 36%. HLARin VRE strains was found to be higher as compared with VSE strains (p <0.005.Conclusion: Antimicrobial resistance is increasing in enterococci strains. Therefore a follow-up is required resistancepattern including both vancomycin resistance and HLAR. J Microbiol Infect Dis 2013; 3(3: 100-103Key words: Enterococcus spp. , vancomycin, linezolid, aminoglycoside, resistance

  1. EmtA, a rRNA methyltransferase conferring high-level evernimicin resistance

    DEFF Research Database (Denmark)

    Mann, P. A.; Xiong, L.; Mankin, A. S.

    2001-01-01

    Enterococcus faecium strain 9631355 was isolated from animal sources on the basis of its resistance to the growth promotant avilamycin. The strain also exhibited high-level resistance to evernimicin, a drug undergoing evaluation as a therapeutic agent in humans. Ribosomes from strain 9631355...... exhibited a dramatic reduction in evernimicin binding, shown by both cell-free translation assays and direct-binding assays. The resistance determinant was cloned from strain 9631355; sequence alignments suggested it was a methyltransferase and therefore it was designated emtA for evernimicin...... methyltransferase. Evernimicin resistance was transmissible and emtA was localized to a plasmid-borne insertion element. Purified EmtA methylated 50S subunits from an evernimicin-sensitive strain 30-fold more efficiently than those from a resistant strain. Reverse transcription identified a pause site...

  2. Unique Flap Conformation in an HIV-1 Protease with High-level Darunavir Resistance

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    Masaaki eNakashima

    2016-02-01

    Full Text Available Darunavir (DRV is one of the most powerful protease inhibitors for treating human immunodeficiency virus type-1 (HIV-1 infection and presents a high genetic barrier to the generation of resistant viruses. However, DRV-resistant HIV-1 infrequently emerges from viruses exhibiting resistance to other protease inhibitors. To address this resistance, researchers have gathered genetic information on DRV resistance. In contrast, few structural insights into the mechanism underlying DRV resistance are available. To elucidate this mechanism, we determined the crystal structure of the ligand-free state of a protease with high-level DRV resistance and six DRV resistance-associated mutations (including I47V and I50V, which we generated by in vitro selection. This crystal structure showed a unique curling conformation at the flap regions that was not found in the previously reported ligand-free protease structures. Molecular dynamics simulations indicated that the curled flap conformation altered the flap dynamics. These results suggest that the preference for a unique flap conformation influences DRV binding. These results provide new structural insights into elucidating the molecular mechanism of DRV resistance and aid to develop PIs effective against DRV-resistant viruses.

  3. Chromosomally and Extrachromosomally Mediated High-Level Gentamicin Resistance in Streptococcus agalactiae

    OpenAIRE

    Sendi, Parham; Furitsch, Martina; Mauerer, Stefanie; Florindo, Carlos; Kahl, Barbara C.; Shabayek, Sarah; Berner, Reinhard; Spellerberg, Barbara

    2016-01-01

    Free PMC Article Streptococcus agalactiae (group B Streptococcus [GBS]) is a leading cause of sepsis in neonates. The rate of invasive GBS disease in nonpregnant adults also continues to climb. Aminoglycosides alone have little or no effect on GBS, but synergistic killing with penicillin has been shown in vitro. High-level gentamicin resistance (HLGR) in GBS isolates, however, leads to the loss of a synergistic effect. We therefore performed a multicenter study to determine the frequency o...

  4. Comparison of four methods for testing high-level aminoglycoside resistance in enterococci.

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    Yagupsky, P; Petry, S; Menegus, M A

    1990-02-01

    In a prospective study the prevalence of high-level aminoglycoside resistance (MIC greater than or equal to 2,000 micrograms/ml) among 62 clinically significant enterococci was investigated. A total of 10(5) organisms were inoculated a) onto a plate containing 2,000 micrograms/ml of gentamicin or streptomycin; b) into a microtube for dilution MIC determinations for gentamicin, amikacin, tobramycin and streptomycin; and c) into a single tube containing 500 micrograms/ml of gentamicin, amikacin, tobramycin or streptomycin in supplemented Mueller-Hinton broth. In addition, tubes containing 500 micrograms/ml of gentamicin, amikacin, tobramycin or streptomycin were inoculated with five enterococcal colonies ("crude" method). For 45 of the 62 isolates, MICs of gentamicin, amikacin and tobramycin were less than or equal to 500 micrograms/ml, while 17 (27%) showed high-level resistance. The MICs of streptomycin were less than or equal to 500 micrograms/ml for 42 of 62 isolates, and greater than or equal to 2,000 micrograms/ml for 20 (32.3%). For 8 of the 17 (47%) isolates showing high-level gentamicin resistance, MICs of streptomycin were less than or equal to 500 micrograms/ml. There was complete agreement between the results of the plate method, the microtube dilution MIC and the tube inoculated with 10(5) CFU, but the crude method gave discordant results for two isolates. It is concluded that a tube containing 500 micrograms/ml of aminoglycoside is a simple, accurate and inexpensive method for determining high-level aminoglycoside resistance.

  5. High level of pyrethroid resistance in an Anopheles funestus population of the Chokwe District in Mozambique.

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    Nelson Cuamba

    Full Text Available BACKGROUND: Although Anopheles funestus is difficult to rear, it is crucial to analyse field populations of this malaria vector in order to successfully characterise mechanisms of insecticide resistance observed in this species in Africa. In this study we carried out a large-scale field collection and rearing of An. funestus from Mozambique in order to analyse its susceptibility status to insecticides and to broadly characterise the main resistance mechanisms involved in natural populations. METHODOLOGY/PRINCIPAL FINDINGS: 3,000 F(1 adults were obtained through larval rearing. WHO susceptibility assays indicated a very high resistance to pyrethroids with no mortality recorded after 1 h 30 min exposure and less than 50% mortality at 3 h 30 min. Resistance to the carbamate, bendiocarb was also noted, with 70% mortality after 1h exposure. In contrast, no DDT resistance was observed, indicating that no kdr-type resistance was involved. The sequencing of the acetylcholinesterase gene indicated the absence of the G119S and F455W mutations associated with carbamate and organophosphate resistance. This could explain the absence of malathion resistance in this population. Both biochemical assays and quantitative PCR implicated up-regulated P450 genes in pyrethroid resistance, with GSTs playing a secondary role. The carbamate resistance observed in this population is probably conferred by the observed altered AChE with esterases also involved. CONCLUSION/SIGNIFICANCE: The high level of pyrethroid resistance in this population despite the cessation of pyrethroid use for IRS in 1999 is a serious concern for resistance management strategies such as rotational use of insecticides. As DDT has now been re-introduced for IRS, susceptibility to DDT needs to be closely monitored to prevent the appearance and spread of resistance to this insecticide.

  6. High level of pyrethroid resistance in an Anopheles funestus population of the Chokwe District in Mozambique.

    Science.gov (United States)

    Cuamba, Nelson; Morgan, John C; Irving, Helen; Steven, Andrew; Wondji, Charles S

    2010-06-08

    Although Anopheles funestus is difficult to rear, it is crucial to analyse field populations of this malaria vector in order to successfully characterise mechanisms of insecticide resistance observed in this species in Africa. In this study we carried out a large-scale field collection and rearing of An. funestus from Mozambique in order to analyse its susceptibility status to insecticides and to broadly characterise the main resistance mechanisms involved in natural populations. 3,000 F(1) adults were obtained through larval rearing. WHO susceptibility assays indicated a very high resistance to pyrethroids with no mortality recorded after 1 h 30 min exposure and less than 50% mortality at 3 h 30 min. Resistance to the carbamate, bendiocarb was also noted, with 70% mortality after 1h exposure. In contrast, no DDT resistance was observed, indicating that no kdr-type resistance was involved. The sequencing of the acetylcholinesterase gene indicated the absence of the G119S and F455W mutations associated with carbamate and organophosphate resistance. This could explain the absence of malathion resistance in this population. Both biochemical assays and quantitative PCR implicated up-regulated P450 genes in pyrethroid resistance, with GSTs playing a secondary role. The carbamate resistance observed in this population is probably conferred by the observed altered AChE with esterases also involved. The high level of pyrethroid resistance in this population despite the cessation of pyrethroid use for IRS in 1999 is a serious concern for resistance management strategies such as rotational use of insecticides. As DDT has now been re-introduced for IRS, susceptibility to DDT needs to be closely monitored to prevent the appearance and spread of resistance to this insecticide.

  7. Corynebacterium diphtheriae putative tellurite-resistance protein (CDCE8392_0813 contributes to the intracellular survival in human epithelial cells and lethality of Caenorhabditis elegans

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    Louisy Sanches dos Santos

    2015-08-01

    Full Text Available Corynebacterium diphtheriae, the aetiologic agent of diphtheria, also represents a global medical challenge because of the existence of invasive strains as causative agents of systemic infections. Although tellurite (TeO32- is toxic to most microorganisms, TeO32--resistant bacteria, including C. diphtheriae, exist in nature. The presence of TeO32--resistance (TeR determinants in pathogenic bacteria might provide selective advantages in the natural environment. In the present study, we investigated the role of the putative TeR determinant (CDCE8392_813gene in the virulence attributes of diphtheria bacilli. The disruption of CDCE8392_0813 gene expression in the LDCIC-L1 mutant increased susceptibility to TeO32- and reactive oxygen species (hydrogen peroxide, but not to other antimicrobial agents. The LDCIC-L1 mutant also showed a decrease in both the lethality of Caenorhabditis elegansand the survival inside of human epithelial cells compared to wild-type strain. Conversely, the haemagglutinating activity and adherence to and formation of biofilms on different abiotic surfaces were not regulated through the CDCE8392_0813 gene. In conclusion, the CDCE8392_813 gene contributes to the TeR and pathogenic potential of C. diphtheriae.

  8. Pyrosequencing of antibiotic-contaminated river sediments reveals high levels of resistance and gene transfer elements.

    Science.gov (United States)

    Kristiansson, Erik; Fick, Jerker; Janzon, Anders; Grabic, Roman; Rutgersson, Carolin; Weijdegård, Birgitta; Söderström, Hanna; Larsson, D G Joakim

    2011-02-16

    The high and sometimes inappropriate use of antibiotics has accelerated the development of antibiotic resistance, creating a major challenge for the sustainable treatment of infections world-wide. Bacterial communities often respond to antibiotic selection pressure by acquiring resistance genes, i.e. mobile genetic elements that can be shared horizontally between species. Environmental microbial communities maintain diverse collections of resistance genes, which can be mobilized into pathogenic bacteria. Recently, exceptional environmental releases of antibiotics have been documented, but the effects on the promotion of resistance genes and the potential for horizontal gene transfer have yet received limited attention. In this study, we have used culture-independent shotgun metagenomics to investigate microbial communities in river sediments exposed to waste water from the production of antibiotics in India. Our analysis identified very high levels of several classes of resistance genes as well as elements for horizontal gene transfer, including integrons, transposons and plasmids. In addition, two abundant previously uncharacterized resistance plasmids were identified. The results suggest that antibiotic contamination plays a role in the promotion of resistance genes and their mobilization from environmental microbes to other species and eventually to human pathogens. The entire life-cycle of antibiotic substances, both before, under and after usage, should therefore be considered to fully evaluate their role in the promotion of resistance.

  9. Dissemination of high-level mupirocin-resistant CC22-MRSA-IV in Saxony.

    Science.gov (United States)

    Monecke, Stefan; Ruppelt-Lorz, Antje; Müller, Elke; Reissig, Annett; Thürmer, Alexander; Shore, Anna C; Coleman, David C; Ehricht, Ralf; Jatzwauk, Lutz

    2017-01-01

    Mupirocin is used for eradicating methicillin-resistant S. aureus (MRSA) in nasal colonization. A plasmid-borne gene, mupA , is associated with high-level mupirocin resistance. Despite the fact that, among all MRSA from a tertiary care center in the German state of Saxony, the prevalence of mupA , encoding high-level mupirocin resistance, was approximately 1% over a 15-year period from 2000-2015, a sharp increase to nearly 20% was observed in 2016/2017. DNA microarray profiling revealed that this was due to the dissemination of a variant of CC22-MRSA-IV ("Barnim Epidemic Strain" or "UK-EMRSA-15"), which, in addition to mecA , harbors mupA , aacA-aphD , qacA , and - in most isolates - erm (C). In order to prevent therapy failures and a further spread of this strain, the use of mupirocin should be more stringently controlled as well as guided by susceptibility testing. In addition, MRSA decolonization regimens that rely on other substances, such as betaisodona, polyhexanide or octenidine, should be considered.

  10. High-level fluoroquinolone resistance in ophthalmic clinical isolates belonging to the species Corynebacterium macginleyi.

    Science.gov (United States)

    Eguchi, Hiroshi; Kuwahara, Tomomi; Miyamoto, Tatsuro; Nakayama-Imaohji, Haruyuki; Ichimura, Minoru; Hayashi, Tetsuya; Shiota, Hiroshi

    2008-02-01

    The clinical importance of nondiphtherial Corynebacterium, a ubiquitous member of the normal human microflora of the skin and mucous membrane, for ocular surface infections has been recognized recently. We performed an antimicrobial susceptibility test with Etest strips for three fluoroquinolones (ciprofloxacin, norfloxacin, and levofloxacin) and a taxonomic analysis on 21 isolates of Corynebacterium from ophthalmic samples. Of these, 16 isolates were identified as C. macginleyi at the species level on the basis of 16S rRNA gene sequence comparisons. The remaining five isolates were determined to be C. mastitidis (four) or C. accolens (one). Eleven of the C. macginleyi isolates showed high levels of resistance to all of the fluoroquinolones tested, and one isolate was resistant to norfloxacin alone. An analysis of the amplified quinolone-resistance-determining regions of the gyrA genes revealed that a single amino acid substitution in position 83 of the gyrA product was sufficient to generate the norfloxacin resistance phenotype, and double mutations leading to amino acid changes in positions 83 and 87 were necessary for high-level resistance against the other fluoroquinolones. We conducted the first example of multilocus sequence typing (MLST) analysis on C. macginleyi. The MLST analysis grouped the majority of C. macginleyi isolates into a single lineage, and another molecular strain typing by random amplified polymorphic DNA fragment patterns supported the finding, indicating that a particular lineage of C. macginleyi is dominant on the human ocular surface. This type of population might be particularly adaptable to the milieu on the human ocular surface.

  11. Tellurite-mediated thiol oxidation in Escherichia coli.

    Science.gov (United States)

    Turner, R J; Weiner, J H; Taylor, D E

    1999-09-01

    The oxyanion of tellurium, tellurite (TeO3(2-)), is toxic to most micro-organisms, particularly gram-negative bacteria. The mechanism of tellurite toxicity is presently unknown. Many heavy metals and oxyanions, including tellurite, interact with reduced thiols (RSH). To determine if tellurite interaction with RSH groups is involved in the toxicity mechanism, the RSH content of Escherichia coli cultures was assayed. After exposure to tellurite, cells were harvested and lysed in the presence of the RSH-specific reagent 5,5'-dithiobis(2-nitrobenzoic acid). Upon exposure of tellurite-susceptible cells to TeO3(2-), the RSH content decreased markedly. Resistance to potassium tellurite (Te(r)) in gram-negative bacteria is encoded by plasmids of incompatibility groups IncFI, IncP alpha, IncHI2, IncHI3 and IncHII, as well as the tehAtehB operon from the E. coli chromosome. When cells harbouring a Te(r) determinant were exposed to TeO3(2-), only a small fraction of the RSH content became oxidized. In addition to tellurite-dependent thiol oxidation, the resistance of E. coli mutants affected in proteins involved in disulfide-bond formation (dsb) was investigated. Mutant strains of dsbA and dsbB were found to be hypersensitive to tellurite (MIC 0.008-0.015 microg K2TeO3 ml(-1) compared to wild-type E. coli with MICs of 1-2 microg K2TeO3 ml(-1)). In contrast, dsbC and dsbD mutants showed no hypersensitivity. The results suggest that hypersensitivity to tellurite is reliant on the presence of an isomerase activity and not the thiol oxidase activity of the Dsb proteins. The results establish that the Te(r) determinants play an important role in maintaining homeostasis of the intracellular reducing environment within gram-negative cells through specific reactions with either TeO3(2-) or thiol:tellurium products.

  12. In vitro antibacterial activity of seven Indian spices against high level gentamicin resistant strains of enterococci

    Science.gov (United States)

    Bipin, Chapagain; Chitra, Pai (Bhat); Minakshi, Bhattacharjee

    2015-01-01

    Introduction The aim of the study was to explore the in vitro antibacterial activity of seven ethanolic extracts of spices against high level gentamicin resistant (HLGR) enterococci isolated from human clinical samples. Material and methods Two hundred and fifteen enterococcal strains were isolated from clinical samples. High level gentamicin resistance in ethanolic extracts of cumin (Cuminum cyminum), cinnamon (Cinnamomum zeylanicum), ginger (Zingiber officinale), fenugreek (Trigonella foenum-graecum), cloves (Syzygium aromaticum), cardamom (Elettaria cardamomum Maton) and black pepper (Piper nigrum) were prepared using Soxhlet apparatus. The antibacterial effect of the extracts was studied using the well diffusion method. Statistical analysis was carried out by χ2 test using SPSS 17 software. Results Only cinnamon and ginger were found to have activity against all the isolates, whereas cumin and cloves had a variable effect on the strains. Fenugreek, black pepper and cardamom did not show any effect on the isolates. The zone diameter of inhibition obtained for cinnamon, ginger, cloves and cumin was in the range 31–34 mm, 27–30 mm, 25–26 mm and 19–20 mm respectively. Conclusions Cinnamomum zeylanicum and Z. officinale showed the maximum antibacterial activity against the enterococcal isolates followed by S. aromaticum and C. cyminum. The findings of the study show that spices used in the study can contribute to the development of potential antimicrobial agents for inclusion in the anti-enterococcal treatment regimen. PMID:26322099

  13. [High level of aminoglycoside resistance among Enterococcus faecalis and Enterococcus faecium strains].

    Science.gov (United States)

    Kozuszko, Sylwia; Białucha, Agata; Bogiel, Tomasz; Gospodarek, Eugenia

    2011-01-01

    Enterococcus sp. strains are believed as important reason of serious nosocomial infections currently. These infections are cured by using combination of beta-lactams and aminoglycosides for their treatment. Enterococcus sp. resistant to high-level doses of aminoglycosides, beta-lactams and vancomycin are responsible for therapeutic failure. The aim of our study was to evaluate the incidence of isolation and susceptibility to antibiotics of HLAR Enterococcus sp. strains isolated between 2007 and 2010 from the patients of University Hospital No. 1 of dr A. Jurasz Collegium Medicum of L. Rydygier in Bydgoszcz Nicolaus Copernicus University in Toruń. Amongst 6137 Enterococcus sp. strains 1124 (18,3%) presented HLAR phenotype; 53,1% of them was identified as E. faecalis and 46,9% as E. faecium. The highest percentage of all examined strains was isolated from the patients of different surgery clinics, Intensive Care Units, and Pediatrics, Hematology and Oncology Clinic. HLAR and HLSR phenotypes were noted in E. faecalis, for 45,7% and 27,5% strains, in E. faecium - 29,8% and 9,5%, respectively. HLGR phenotype was presented twice more often in E. faecium than E. faecalis. Highest percentages of E. faecium resistant to glycopeptides and rifampicin were observed when compared with E. faecalis. The highest percentages of strains intermediate, resistant to vancomycin and resistant to glycopeptides were noted for E. faecium strains with phenotypes HLAR, HLGR and HLSR.

  14. High level of gentamicin resistance (HLGR) among enterococcus strains isolated from clinical specimens.

    Science.gov (United States)

    Dadfarma, Narges; Imani Fooladi, Abbas Ali; Oskoui, Mahvash; Mahmoodzadeh Hosseini, Hamideh

    2013-06-01

    Enterococci are pathogens that can cause nosocomial infections and acquire resistance properties via several molecular mechanisms. The aac (6')Ie-aph(2″)Ia gene plays a significant role in the emergence of high-level gentamicin-resistant (HLGR) strains. The screening of resistant strains and the provision of appropriate antibiotic therapy can decide the outcome of serious nosocomial infections. In the present study, 142 enterococci were isolated from patients, and the species were identified using standard methods. An antimicrobial susceptibility test was performed using the disc diffusion method, and the minimum inhibition concentration (MIC) of gentamicin was determined according to the broth micro-dilution method. Additionally, PCR was utilized to detect the aac(6')Ie-aph(2″)Ia gene, the presence of which was confirmed by digestion with Sca1 and sequencing. Of the 142 isolates, 62 (43.7%) were found to exhibit the HLGR phenotype. All except one of the HLGR isolates contained the aac(6')Ie-aph(2″)Ia gene. The prevalence of resistance to other antibiotics and multi-drug resistance (MDR) was higher among the HLGR isolates compared to the non-HLGR isolates. Our results indicate that high prevalence rates of MDR and HLGR enterococci are an important problem associated with medical treatment. Furthermore, the presence of the aac(6')Ie-aph(2″)Ia gene was shown to correspond to the presence of the HLGR phenotype among enterococci. Copyright © 2013 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

  15. Chromosomally and Extrachromosomally Mediated High-Level Gentamicin Resistance in Streptococcus agalactiae.

    Science.gov (United States)

    Sendi, Parham; Furitsch, Martina; Mauerer, Stefanie; Florindo, Carlos; Kahl, Barbara C; Shabayek, Sarah; Berner, Reinhard; Spellerberg, Barbara

    2016-01-04

    Streptococcus agalactiae (group B Streptococcus [GBS]) is a leading cause of sepsis in neonates. The rate of invasive GBS disease in nonpregnant adults also continues to climb. Aminoglycosides alone have little or no effect on GBS, but synergistic killing with penicillin has been shown in vitro. High-level gentamicin resistance (HLGR) in GBS isolates, however, leads to the loss of a synergistic effect. We therefore performed a multicenter study to determine the frequency of HLGR GBS isolates and to elucidate the molecular mechanisms leading to gentamicin resistance. From eight centers in four countries, 1,128 invasive and colonizing GBS isolates were pooled and investigated for the presence of HLGR. We identified two strains that displayed HLGR (BSU1203 and BSU452), both of which carried the aacA-aphD gene, typically conferring HLGR. However, only one strain (BSU1203) also carried the previously described chromosomal gentamicin resistance transposon designated Tn3706. For the other strain (BSU452), plasmid purification and subsequent DNA sequencing resulted in the detection of plasmid pIP501 carrying a remnant of a Tn3 family transposon. Its ability to confer HLGR was proven by transfer into an Enterococcus faecalis isolate. Conversely, loss of HLGR was documented after curing both GBS BSU452 and the transformed E. faecalis strain from the plasmid. This is the first report showing plasmid-mediated HLGR in GBS. Thus, in our clinical GBS isolates, HLGR is mediated both chromosomally and extrachromosomally. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  16. Genotypic and phenotypic characterization of methicillin-resistant Staphylococcus aureus (MRSA) clones with high-level mupirocin resistance.

    Science.gov (United States)

    González-Domínguez, María; Seral, Cristina; Potel, Carmen; Sáenz, Yolanda; Álvarez, Maximiliano; Torres, Carmen; Castillo, Francisco Javier

    2016-06-01

    A high proportion of methicillin-resistant Staphylococcus aureus isolates recovered in one year period showed high-level mupirocin-resistance (HLMUPR-MRSA) in our environment (27.2%). HLMUPR-MRSA isolates were mainly collected from skin and soft tissue samples, and diabetes was the main related comorbidity condition. These isolates were more frequently found in vascular surgery. HLMUPR-MRSA was more resistant to aminoglycosides than mupirocin-susceptible MRSA, linked to the presence of bifunctional and/or nucleotidyltransferase enzymes with/without macrolide resistance associated with the msr(A) gene. Most of HLMUPR-MRSA isolates belonged to ST125/t067. Nine IS257-ileS2 amplification patterns (p3 was the most frequent) were observed in HLMUPR-MRSA isolates, suggesting the presence of several mupirocin-resistance-carrying plasmids in our environment and promoting the emergence of mupirocin resistance. The presence of the same IS257-ileS2 amplification pattern p3 in 65% of HLMUPR-MRSA, all of them ST125/t067, suggests a clonal spread in our hospital and community environment which could explain the high prevalence of HLMUPR-MRSA during the study period. An outbreak situation or an increase in mupirocin consumption was not observed. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Plasmid metagenome reveals high levels of antibiotic resistance genes and mobile genetic elements in activated sludge.

    Directory of Open Access Journals (Sweden)

    Tong Zhang

    Full Text Available The overuse or misuse of antibiotics has accelerated antibiotic resistance, creating a major challenge for the public health in the world. Sewage treatment plants (STPs are considered as important reservoirs for antibiotic resistance genes (ARGs and activated sludge characterized with high microbial density and diversity facilitates ARG horizontal gene transfer (HGT via mobile genetic elements (MGEs. However, little is known regarding the pool of ARGs and MGEs in sludge microbiome. In this study, the transposon aided capture (TRACA system was employed to isolate novel plasmids from activated sludge of one STP in Hong Kong, China. We also used Illumina Hiseq 2000 high-throughput sequencing and metagenomics analysis to investigate the plasmid metagenome. Two novel plasmids were acquired from the sludge microbiome by using TRACA system and one novel plasmid was identified through metagenomics analysis. Our results revealed high levels of various ARGs as well as MGEs for HGT, including integrons, transposons and plasmids. The application of the TRACA system to isolate novel plasmids from the environmental metagenome, coupled with subsequent high-throughput sequencing and metagenomic analysis, highlighted the prevalence of ARGs and MGEs in microbial community of STPs.

  18. Plasmid metagenome reveals high levels of antibiotic resistance genes and mobile genetic elements in activated sludge.

    Science.gov (United States)

    Zhang, Tong; Zhang, Xu-Xiang; Ye, Lin

    2011-01-01

    The overuse or misuse of antibiotics has accelerated antibiotic resistance, creating a major challenge for the public health in the world. Sewage treatment plants (STPs) are considered as important reservoirs for antibiotic resistance genes (ARGs) and activated sludge characterized with high microbial density and diversity facilitates ARG horizontal gene transfer (HGT) via mobile genetic elements (MGEs). However, little is known regarding the pool of ARGs and MGEs in sludge microbiome. In this study, the transposon aided capture (TRACA) system was employed to isolate novel plasmids from activated sludge of one STP in Hong Kong, China. We also used Illumina Hiseq 2000 high-throughput sequencing and metagenomics analysis to investigate the plasmid metagenome. Two novel plasmids were acquired from the sludge microbiome by using TRACA system and one novel plasmid was identified through metagenomics analysis. Our results revealed high levels of various ARGs as well as MGEs for HGT, including integrons, transposons and plasmids. The application of the TRACA system to isolate novel plasmids from the environmental metagenome, coupled with subsequent high-throughput sequencing and metagenomic analysis, highlighted the prevalence of ARGs and MGEs in microbial community of STPs.

  19. High Level Aminoglycoside Resistance and Distribution of Aminoglycoside Resistant Genes among Clinical Isolates of Enterococcus Species in Chennai, India

    Directory of Open Access Journals (Sweden)

    Elango Padmasini

    2014-01-01

    Full Text Available Enterococci are nosocomial pathogen with multiple-drug resistance by intrinsic and extrinsic mechanisms. Aminoglycosides along with cell wall inhibitors are given clinically for treating enterococcal infections. 178 enterococcal isolates were analyzed in this study. E. faecalis is identified to be the predominant Enterococcus species, along with E. faecium, E. avium, E. hirae, E. durans, E. dispar and E. gallinarum. High level aminoglycoside resistance (HLAR by MIC for gentamicin (GM, streptomycin (SM and both (GM + SM antibiotics was found to be 42.7%, 29.8%, and 21.9%, respectively. Detection of aminoglycoside modifying enzyme encoding genes (AME in enterococci was identified by multiplex PCR for aac(6′-Ie-aph(2′′-Ia; aph(2′′-Ib; aph(2′′-Ic; aph(2′′-Id and aph(3′-IIIa genes. 38.2% isolates carried aac(6′-Ie-aph(2′′-Ia gene and 40.4% isolates carried aph(3′-IIIa gene. aph(2′′-Ib; aph(2′′-Ic; aph(2′′-Id were not detected among our study isolates. aac(6′-Ie-aph(2′′-Ia and aph(3′-IIIa genes were also observed in HLAR E. durans, E. avium, E. hirae, and E. gallinarum isolates. This indicates that high level aminoglycoside resistance genes are widely disseminated among isolates of enterococci from Chennai.

  20. [Vancomycin and high-level aminoglycoside resistant Enterococcus carriage and the risk factors related to resistance in hospitalized patients].

    Science.gov (United States)

    Yildirim, Mustafa; Sencan, Irfan; Ozdemir, Davut; Oksüz, Sükrü; Yilmaz, Zeynep; Sahin, Idris

    2007-04-01

    The aims of this study were to detect the prevalence of fecal vancomycin resistant Enterococcus (VRE) colonization with high-level resistance to aminoglycoside and other antibiotics and, the risk factors related to resistance in hospitalized patients in Düzce Medical Faculty Hospital, Turkey. A total of 105 patients (61 from internal medicine, 44 from surgery clinics; 54.3% female, mean age: 47.2 +/- 24.54 years) were included to the study and a single stool sample was collected from each of the patients. Specimens were cultivated in Enterococcus selective media (BioMerieux, France), and the isolates were identified by conventional microbiological methods together with the API 20 Strep test. Beta-lactamase activities of the isolates were tested with nitrocefin disk, and antibiotic susceptibilities were determined by the disk diffusion method. Enterococcus spp. were isolated from 81 (77%) of the patients' samples and 60.5% were identified as E. faecium, 13.6% as E. faecalis, 11.1% as E. gallinarum, 7.4% as E. durans, 2.5% as E. raffinosus, 2.5% as E. mundtii, 1.2% as E. casseliflavus, and 1.2% as E. avium. High-level streptomycin and gentamicin resistance rates were found in 19.8% and 9.9% of the isolates, respectively. The resistance rates for the other antibiotics were found as follows; 18.5% to ampicillin, 27.2% to penicilin, 34.6% to nitrofurantoin, 65.4% to norfloxacin, and 70.4% to both tetracycline and ciprofloxacin. No vancomycin resistance was detected, and none of the enterococci had beta-lactamase activity. Long hospitalization period, antibiotic usage and experience of intra-abdominal operation were found as the significant risk factors for colonization of the resistant bacteria. Our results demonstrated that there was no fecal VRE carriage in our hospital during the study period, however, it was concluded that the screening tests should be done periodically in order to detect resistant strains as soon as possible.

  1. Selenite Protection of Tellurite Toxicity towards Escherichia coli

    Directory of Open Access Journals (Sweden)

    Helen A. Vrionis

    2015-12-01

    Full Text Available In this work the influence of selenite on metal resistance in Escherichia coli was examined. Both synergistic and antagonistic resistance and toxicities were found upon co exposure with selenite. In wild type cells co-exposure to selenite had little effect on arsenic resistance, decreased resistance to cadmium and mercury but led to a dramatic increased resistance to tellurite of 32 fold. Due to the potential importance of thiol chemistry in metal biochemistry, deletion strains in γ-glutamylcysteine synthetase (key step in glutathione biosynthesis, encoded by gshA, thioredoxin (trxA, glutaredoxin (grxA, glutathione oxidoreductase (gor, and the periplasmic glutathione transporter (cydD were also evaluated for resistance to various metals in the presence of selenite. The protective effect of selenite on tellurite toxicity was seen in several of the mutants and was pronounced in the gshA mutant were resistance to tellurite was increased up to 1000 fold relative to growth in the absence of selenite. Thiol oxidation studies revealed a faster rate of loss of reduced thiol content in the cell with selenite than with tellurite, indicating differential thiol reactivity. Selenite addition resulted in reactive oxygen species (ROS production equivalent to levels associated with H2O2 addition. Tellurite addition resulted in considerably lower ROS generation while vanadate and chromate treatment did not increase ROS production above that of background. This work shows increased resistance towards most oxyanions in mutants of thiol redox suggesting that metalloid reaction with thiol components such as glutathione actually enhances toxicity of some metalloids.

  2. High-level gentamicin resistance and vancomycin resistance in clinical isolates of enterococci in a tertiary care hospital in eastern Nepal.

    Science.gov (United States)

    Nepal, H P; Khanal, B; Acharya, A; Gyawali, N; Jha, P K; Paudel, R

    2012-03-01

    High-level gentamicin resistance and vancomycin resistance in enterococci, a family of important opportunistic pathogens, have emerged as a significant clinical problem over recent years. The present study was conducted to determine the high-level gentamicin and vancomycin resistance among the clinical isolates of enterococci. A total of 110 phenotypically identified enterococcal isolates were subjected to determination of high-level gentamicin resistance (by disk diffusion and agar dilution methods) and vancomycin resistance (by agar screening and agar dilution methods). About 36% of the isolates were found to have high-level gentamicin resistance, which indicates that gentamicin no longer remains an appropriate choice for inclusion in combination therapy with cell wall-active agents. Ten percent isolates exhibited resisance to vancomycin during screening. However, agar dilution confirmed that the isolates did not have resistance to vancomycin but had reduced susceptibility to it, which indicates their impending emergence of resistance to vancomycin.

  3. Tellurite-, tellurate-, and selenite-based anaerobic respiration by strain CM-3 isolated from gold mine tailings.

    Science.gov (United States)

    Maltman, Chris; Piercey-Normore, Michele D; Yurkov, Vladimir

    2015-09-01

    The newly discovered strain CM-3, a Gram-negative, rod-shaped bacterium from gold mine tailings of the Central Mine in Nopiming Provincial Park, Canada, is capable of dissimilatory anaerobic reduction of tellurite, tellurate, and selenite. CM-3 possesses very high level resistance to these oxides, both aerobically and anaerobically. During aerobic growth, tellurite and tellurate resistance was up to 1500 and 1000 µg/ml, respectively. In the presence of selenite, growth occurred at the highest concentration tested, 7000 µg/ml. Under anaerobic conditions, resistance was decreased to 800 µg/ml for the Te oxides; however, much like under aerobic conditions, growth with selenite still took place at 7000 µg/ml. In the absence of oxygen, CM-3 couples oxide reduction to an increase in biomass. Following an initial drop in viable cells, due to switching from aerobic to anaerobic conditions, there was an increase in CFU/ml greater than one order of magnitude in the presence of tellurite (6.6 × 10(3)-8.6 × 10(4) CFU/ml), tellurate (4.6 × 10(3)-1.4 × 10(5) CFU/ml), and selenite (2.7 × 10(5)-5.6 × 10(6) CFU/ml). A control culture without metalloid oxides showed a steady decrease in CFU/ml with no recovery. ATP production was also increased in the presence of each oxide, further indicating anaerobic respiration. Partial 16S rRNA gene sequencing revealed a 99.0 % similarity of CM-3 to Pseudomonas reactans.

  4. High Levels of Transmitted HIV Drug Resistance in a Study in Papua New Guinea.

    Science.gov (United States)

    Lavu, Evelyn; Kave, Ellan; Mosoro, Euodia; Markby, Jessica; Aleksic, Eman; Gare, Janet; Elsum, Imogen A; Nano, Gideon; Kaima, Petronia; Dala, Nick; Gurung, Anup; Bertagnolio, Silvia; Crowe, Suzanne M; Myatt, Mark; Hearps, Anna C; Jordan, Michael R

    2017-01-01

    Papua New Guinea is a Pacific Island nation of 7.3 million people with an estimated HIV prevalence of 0.8%. ART initiation and monitoring are guided by clinical staging and CD4 cell counts, when available. Little is known about levels of transmitted HIV drug resistance in recently infected individuals in Papua New Guinea. Surveillance of transmitted HIV drug resistance in a total of 123 individuals recently infected with HIV and aged less than 30 years was implemented in Port Moresby (n = 62) and Mount Hagen (n = 61) during the period May 2013-April 2014. HIV drug resistance testing was performed using dried blood spots. Transmitted HIV drug resistance was defined by the presence of one or more drug resistance mutations as defined by the World Health Organization surveillance drug resistance mutations list. The prevalence of non-nucleoside reverse transcriptase inhibitor transmitted HIV drug resistance was 16.1% (95% CI 8.8%-27.4%) and 8.2% (95% CI 3.2%-18.2%) in Port Moresby and Mount Hagen, respectively. The prevalence of nucleoside reverse transcriptase inhibitor transmitted HIV drug resistance was 3.2% (95% CI 0.2%-11.7%) and 3.3% (95% CI 0.2%-11.8%) in Port Moresby and Mount Hagen, respectively. No protease inhibitor transmitted HIV drug resistance was observed. The level of non-nucleoside reverse transcriptase inhibitor drug resistance in antiretroviral drug naïve individuals recently infected with HIV in Port Moresby is amongst the highest reported globally. This alarming level of transmitted HIV drug resistance in a young sexually active population threatens to limit the on-going effective use of NNRTIs as a component of first-line ART in Papua New Guinea. To support the choice of nationally recommended first-line antiretroviral therapy, representative surveillance of HIV drug resistance among antiretroviral therapy initiators in Papua New Guinea should be urgently implemented.

  5. First report of Ser653Asn mutation endowing high-level resistance to imazamox in downy brome (Bromus tectorum L.).

    Science.gov (United States)

    Kumar, Vipan; Jha, Prashant

    2017-12-01

    Bromus tectorum L. is one of the most troublesome grass weed species in cropland and non-cropland areas of the northwestern USA. In summer 2016, a B. tectroum accession (R) that survived imazamox at the field-use rate (44 g ha -1 ) in an imidazolinone-tolerant (IMI-tolerant or Clearfield™) winter wheat field was collected from a wheat field in Carter County, MT, USA. The aim of this study was to determine the resistance profile of the B. tectroum R accession to imazamox and other ALS inhibitors, and investigate the mechanism of resistance to imazamox. The R B. tectorum accession had a high-level resistance (110.1-fold) to imazamox (IMI) and low to moderate-levels cross-resistance to pyroxsulam (TP) (4.6-fold) and propoxycarbazone (SCT) (13.9-fold). The R accession was susceptible to sulfosulfuron (SU) and quizalofop and clethodim (ACCase inhibitors), paraquat (PS I inhibitor), glyphosate (EPSPS inhibitor) and glufosinate (GS inhibitor). Sequence analysis of the ALS gene revealed a single, target-site Ser653Asn mutation in R plants. Pretreatment of malathion followed by imazamox at 44 or 88 g ha -1 did not reverse the resistance phenotype. This is the first report of evolution of cross-resistance to ALS-inhibiting herbicides in B. tectorum. A single-point mutation, Ser653Asn, was identified, conferring the high-level resistance to imazamox. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  6. High-level gentamicin resistance mediated by a Tn4001-like transposon in seven nonclonal hospital isolates of Streptococcus pasteurianus.

    Science.gov (United States)

    Chow, Viola C Y; Hawkey, Peter M; Chan, Edward W C; Chin, Miu L; Au, T K; Fung, Danny K C; Chan, Raphael C Y

    2007-07-01

    We report on the first occurrence of high-level gentamicin resistance (MICs > or = 512 microg/ml) in seven clinical isolates of Streptococcus pasteurianus from Hong Kong. These seven isolates were confirmed to be the species S. pasteurianus on the basis of nucleotide sequencing of the superoxide dismutase (sodA) gene. Epidemiological data as well as the results of pulse-field gel electrophoresis analysis suggested that the seven S. pasteurianus isolates did not belong to the same clone. Molecular characterization showed that they carried a chromosomal, transposon-borne resistance gene [aac(6')Ie-aph(2'')Ia] which was known to encode a bifunctional aminoglycoside-modifying enzyme. The genetic arrangement of this transposon was similar to that of Tn4001, a transposon previously recovered from Staphylococcus aureus and other gram-positive isolates. Genetic linkage with other resistance elements, such as the ermB gene for erythromycin resistance, was not evident. On the basis of these findings, we suggest that routine screening for high-level gentamicin resistance should be recommended for all clinically significant blood culture isolates. This is to avoid the inadvertent use of short-course combination therapy with penicillin and gentamicin, which may lead to the failure of treatment for endocarditis, the selection of drug-resistant Streptococcus pasteurianus and other gram-positive organisms, as well as the unnecessary usage of gentamicin, a drug with potential toxicity.

  7. Plasmid metagenome reveals high levels of antibiotic resistance genes and mobile genetic elements in activated sludge

    OpenAIRE

    Zhang, T; Zhang, XX; Ye, L

    2011-01-01

    The overuse or misuse of antibiotics has accelerated antibiotic resistance, creating a major challenge for the public health in the world. Sewage treatment plants (STPs) are considered as important reservoirs for antibiotic resistance genes (ARGs) and activated sludge characterized with high microbial density and diversity facilitates ARG horizontal gene transfer (HGT) via mobile genetic elements (MGEs). However, little is known regarding the pool of ARGs and MGEs in sludge microbiome. In thi...

  8. High-level nickel resistance in Alcaligenes xylosoxydans 31A and Alcaligenes eutrophus KTO2

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, T.; Stoppel, R.D.; Schlegel, H.G. (Inst. fuer Mikrobiologie der Georg-August-Univ., Goettingen (West Germany))

    1991-11-01

    Two new nickel-resistant strains of Alcaligenes species were selected from a large number (about 400) of strains isolated from ecosystems polluted by heavy metals and were studied on the physiological and molecular level. Alcaligenes xylosoxydans 31A is a heterotrophic bacterium, and Alcaligenes eutrophus KTO2 is an autotrophic aerobic hydrogen-oxidizing bacterium. Both strains carry - among other plasmids - a megaplasmid determining resistance to 20 to 50 mM NiCl{sub 2} and 20 mM CoCl{sub 2} (when growing in defined Tris-buffered media). Megaplasmid pTOM8, pTOM9 from strain 31A, and pGOE2 from strain KTO2 confer nickel resistance to the same degree to transconjugants of all strains of A. eutrophus tested but were not transferred to Escherichia coli. However, DNA fragments carrying the nickel resistance genes, cloned into broad-host- range vector pVDZ{prime}2, confer resistance to A. eutrophus derivatives as well as E. coli. The DNA fragments of both bacteria, TBA8, TBA9, and GBA (14.5-kb BamHI fragments), appear to be identical. They share equal size, restriction maps, and strong DNA homology but are largely different from fragment HKI of nickel-cobalt resistance plasmid pMOL28 of A. eutrophus CH34.

  9. High-Level Nickel Resistance in Alcaligenes xylosoxydans 31A and Alcaligenes eutrophus KTO2.

    Science.gov (United States)

    Schmidt, T; Stoppel, R D; Schlegel, H G

    1991-11-01

    Two new nickel-resistant strains of Alcaligenes species were selected from a large number (about 400) of strains isolated from ecosystems polluted by heavy metals and were studied on the physiological and molecular level. Alcaligenes xylosoxydans 31A is a heterotrophic bacterium, and Alcaligenes eutrophus KTO2 is an autotrophic aerobic hydrogen-oxidizing bacterium. Both strains carry-among other plasmids-a megaplasmid determining resistance to 20 to 50 mM NiCl(2) and 20 mM CoCl(2) (when growing in defined Tris-buffered media). Megaplasmids pTOM8, pTOM9 from strain 31A, and pGOE2 from strain KTO2 confer nickel resistance to the same degree to transconjugants of all strains of A. eutrophus tested but were not transferred to Escherichia coli. However, DNA fragments carrying the nickel resistance genes, cloned into broad-hostrange vector pVDZ'2, confer resistance to A. eutrophus derivatives as well as E. coli. The DNA fragments of both bacteria, TBA8, TBA9, and GBA (14.5-kb BamHI fragments), appear to be identical. They share equal size, restriction maps, and strong DNA homology but are largely different from fragment HKI of nickel-cobalt resistance plasmid pMOL28 of A. eutrophus CH34.

  10. Atovaquone tolerance in Plasmodium falciparum parasites selected for high-level resistance to a dihydroorotate dehydrogenase inhibitor.

    Science.gov (United States)

    Guler, Jennifer L; White, John; Phillips, Margaret A; Rathod, Pradipsinh K

    2015-01-01

    Atovaquone is a component of Malarone, a widely prescribed antimalarial combination, that targets malaria respiration. Here we show that parasites with high-level resistance to an inhibitor of dihydroorotate dehydrogenase demonstrate unexpected atovaquone tolerance. Fortunately, the tolerance is diminished with proguanil, the second partner in Malarone. It is important to understand such "genetic cross talk" between respiration and pyrimidine biosynthesis since many antimalarial drug development programs target these two seemingly independent pathways. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  11. Atovaquone Tolerance in Plasmodium falciparum Parasites Selected for High-Level Resistance to a Dihydroorotate Dehydrogenase Inhibitor

    OpenAIRE

    Guler, Jennifer L.; White, John; Phillips, Margaret A.; Rathod, Pradipsinh K.

    2014-01-01

    Atovaquone is a component of Malarone, a widely prescribed antimalarial combination, that targets malaria respiration. Here we show that parasites with high-level resistance to an inhibitor of dihydroorotate dehydrogenase demonstrate unexpected atovaquone tolerance. Fortunately, the tolerance is diminished with proguanil, the second partner in Malarone. It is important to understand such “genetic cross talk” between respiration and pyrimidine biosynthesis since many antimalarial drug developm...

  12. High-level amikacin resistance in Pseudomonas aeruginosa associated with a 3'-phosphotransferase with high affinity for amikacin.

    Science.gov (United States)

    Torres, C; Perlin, M H; Baquero, F; Lerner, D L; Lerner, S A

    2000-08-01

    This work describes the characterization of the phosphotransferase enzymatic activity responsible for amikacin resistance in two clinical Pseudomona aeruginosa strains, isolated from a hospital that used amikacin as first-line aminoglycoside. Amikacin-resistant P. aeruginosa PA40 and PA43 (MIC: 128 mg/l) were shown to have APH activity with a substrate profile similar to that of APH(3')-VI. The enzyme from P. aeruginosa PA40 was purified to > 70% homogeneity. The Km of amikacin for this enzyme was 1.4 microM, the Vmax/Km ratio for amikacin was higher than for the other aminoglycosides tested and PCR and DNA sequencing ruled out the presence of aph(3')-IIps. Amikacin resistance in this strain was, therefore, associated with APH(3')-VI and the high affinity of this enzyme for amikacin could explain the high-level resistance that we observed.

  13. Transgressive segregation for very low and high levels of basal resistance to powdery mildew in barley

    NARCIS (Netherlands)

    Aghnoum, R.; Niks, R.E.

    2011-01-01

    Basal resistance of barley to powdery mildew is a quantitatively inherited trait that limits the growth and sporulation of barley powdery mildew pathogen by a non-hypersensitive mechanism of defense. Two experimental barley lines were developed with a very high (ErBgh) and low (EsBgh) level of basal

  14. Title: High-level cefotaxime-resistant Proteus mirabilis strain isolated ...

    African Journals Online (AJOL)

    oaca

    lactamase genes encoding TEM-2, CTX-M-8, TEM-24, and an AmpC enzyme. .... F80lazDM15) and nalidixic acid resistant E. coli K12 were used ... Transformation experiments were carried out by using E. coli DH5α as the recipient. Transformants were selected on Luria-Bertani medium agar plates supplemented with ...

  15. High-level cefotaxime-resistant Proteus mirabilis strain isolated from ...

    African Journals Online (AJOL)

    Antimicrobial susceptibility was determined with the disk diffusion method according to Clinical and Laboratory Standards Institute (CLSI) guidelines and revealed that this strain was resistant to expanded-spectrum β-lactams. Analysis of P. mirabilis FS6449 by double-disk synergy test yielded a positive result suggesting the ...

  16. High levels of pre-treatment HIV drug resistance and treatment failure in Nigerian children

    NARCIS (Netherlands)

    Boerma, Ragna S.; Boender, T. Sonia; Sigaloff, Kim C. E.; Rinke de Wit, Tobias F.; van Hensbroek, Michael Boele; Ndembi, Nicaise; Adeyemo, Titilope; Temiye, Edamisan O.; Osibogun, Akin; Ondoa, Pascale; Calis, Job C.; Akanmu, Alani Sulaimon

    2016-01-01

    Pre-treatment HIV drug resistance (PDR) is an increasing problem in sub-Saharan Africa. Children are an especially vulnerable population to develop PDR given that paediatric second-line treatment options are limited. Although monitoring of PDR is important, data on the paediatric prevalence in

  17. High level of resistance of Plasmodium falciparum to sulfadoxine-pyrimethamine in children in Tanzania

    DEFF Research Database (Denmark)

    Rønn, A M; Msangeni, H A; Mhina, J

    1996-01-01

    In many areas of tropical Africa affected by chloroquine-resistant Plasmodium falciparum, a combination of sulfadoxine and pyrimethamine (S-P) is used for alternative medication, especially in young children. In Magoda village in Muheza District, north-eastern Tanzania, 38 children 1-10 years of ...... intervention with weekly dapsone-pyrimethamine between May 1993 and May 1994 seems to have been the most important....

  18. High levels of inflammation and insulin resistance in obstructive sleep apnea patients with hypertension.

    Science.gov (United States)

    Qian, Xiaoshun; Yin, Tong; Li, Tianzhi; Kang, Chunyan; Guo, Ruibiao; Sun, Baojun; Liu, Changting

    2012-08-01

    Hypertension induced by obstructive sleep apnea (OSA) may be multifactorial in origin, and systemic inflammation is one of the major factors. However, OSA patients do not always have the identical probability with hypertension even in patients with the same history and degree of OSA. The aim of this study was to compare the levels of inflammation and insulin resistance in two groups of patients who had the same degree as well as the same long history of OSA, but with/without hypertension. OSA patients (Apnea Hyponea Index, AHI ≥ 40/h, n = 70) were examined by polysomnography and blood analysis for the measurements of fasting plasma glucose, serum insulin (FINS), high-sensitivity C-reactive protein (CRP), peptide C,TNF-α, IL-6, and IL-10. Patients with hypertension (n = 40) had higher level of LDL-C and lower HDL-C levels than patients without hypertension. Almost half (16/40) of OSA patients with hypertension had family history of hypertension. Moreover in OSA patients with hypertension, the levels of TNF-α, IL-6, and CRP were higher, but IL-10 was lower than those without hypertension. FINS, peptide C, HOMA-IR, and HOMA-islet were also higher in OSA patients with hypertension. OSA patients with hypertension have higher level of inflammation and insulin resistance. Systemic inflammation and insulin resistance are both important factors for the development of hypertension in OSA patients.

  19. High-level and novel mechanisms of carbapenem resistance in Gram-negative bacteria from tertiary hospitals in Nigeria.

    Science.gov (United States)

    Ogbolu, D O; Webber, M A

    2014-05-01

    To determine the occurrence and molecular basis of carbapenem resistance in Gram-negative bacteria from tertiary hospitals in Nigeria, 182 non-duplicate Gram-negative bacterial isolates were investigated for antimicrobial susceptibility, presence of carbapenemases (tested phenotypically and genotypically), random amplified polymorphic DNA (RAPD) typing, plasmid sizing and replicon typing. Minimum inhibitory concentrations of carbapenems showed a high degree of resistance, with 67 isolates (36.8%) being resistant to all carbapenems, of which 40 (59.7%) produced enzymes able to hydrolyse imipenem. PCR and sequencing identified only 10 isolates (5.5%) carrying known carbapenemase genes, including bla(NDM), bla(VIM) and bla(GES). The majority of phenotypically carbapenem-resistant and carbapenemase-producing isolates did not carry a known carbapenemase gene. Transconjugant or transformant plasmid sizes were estimated to be 115 kb for bla(NDM)- and 93 kb for bla(VIM)-carrying plasmids. These plasmids were untypeable for replicon/incompatibility and transferred various other genes including plasmid-mediated quinolone resistance (PMQR) genes and bla(CTX-M-15). Typing showed that the isolates in this study were not clonally related. There is a high level of carbapenem resistance in Nigeria. As well as the globally relevant carbapenemases (bla(NDM), bla(VIM) and bla(GES)), there are other unknown gene(s) or variant(s) in circulation able to hydrolyse carbapenems and confer high-level resistance. Copyright © 2014 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  20. High levels of pre-treatment HIV drug resistance and treatment failure in Nigerian children

    Directory of Open Access Journals (Sweden)

    Ragna S Boerma

    2016-11-01

    Full Text Available Introduction: Pre-treatment HIV drug resistance (PDR is an increasing problem in sub-Saharan Africa. Children are an especially vulnerable population to develop PDR given that paediatric second-line treatment options are limited. Although monitoring of PDR is important, data on the paediatric prevalence in sub-Saharan Africa and its consequences for treatment outcomes are scarce. We designed a prospective paediatric cohort study to document the prevalence of PDR and its effect on subsequent treatment failure in Nigeria, the country with the second highest number of HIV-infected children in the world. Methods: HIV-1-infected children ≤12 years, who had not been exposed to drugs for the prevention of mother-to-child transmission (PMTCT, were enrolled between 2012 and 2013, and followed up for 24 months in Lagos, Nigeria. Pre-antiretroviral treatment (ART population-based pol genotypic testing and six-monthly viral load (VL testing were performed. Logistic regression analysis was used to assess the effect of PDR (World Health Organization (WHO list for transmitted drug resistance on subsequent treatment failure (two consecutive VL measurements >1000 cps/ml or death. Results: Of the total 82 PMTCT-naïve children, 13 (15.9% had PDR. All 13 children harboured non-nucleoside reverse transcriptase inhibitor (NNRTI mutations, of whom seven also had nucleoside reverse transcriptase inhibitor resistance. After 24 months, 33% had experienced treatment failure. Treatment failure was associated with PDR and a higher log VL before treatment initiation (adjusted odds ratio (aOR 7.53 (95%CI 1.61–35.15 and 2.85 (95%CI 1.04–7.78, respectively. Discussion: PDR was present in one out of six Nigerian children. These high numbers corroborate with recent findings in other African countries. The presence of PDR was relevant as it was the strongest predictor of first-line treatment failure. Conclusions: Our findings stress the importance of implementing fully

  1. Genomic sequences of Streptococcus agalactiae with high-level gentamicin resistance, collected in the BSAC bacteraemia surveillance.

    Science.gov (United States)

    Doumith, Michel; Mushtaq, Shazad; Martin, Veronique; Chaudhry, Aiysha; Adkin, Rachael; Coelho, Juliana; Chalker, Vicki; MacGowan, Alasdair; Woodford, Neil; Livermore, David M

    2017-10-01

    Like other streptococci, Streptococcus agalactiae typically has intrinsic low-level aminoglycoside resistance. High-level gentamicin resistance was seen in 2 of 1125 isolates collected in the BSAC Bacteraemia Surveillance Programme between 2001 and 2014. These organisms, both isolated in 2014, were characterized. Identifications were by latex agglutination, MICs by BSAC agar dilution and sequencing by Illumina methodology. Gentamicin MICs were >1024 mg/L versus a species mode of 8 mg/L; both isolates also were unusually ciprofloxacin resistant with MICs of 64 mg/L versus a species mode of 1 mg/L. They were distinct by sequence, but both belonged to the ST19 clone, which occurs globally. Both had aac(6')-aph(2″), carried by different transposons, explaining their gentamicin resistance, and had gyrA[81:S-L];parC[79:S-Y], accounting for ciprofloxacin resistance. These are the first multiresistant S. agalactiae with the bifunctional AAC(6')-APH(2″) enzyme to be reported in the UK for >10 years. Despite belonging to the same clonal complex, the two isolates and their resistance transposons were distinct. Both retained full susceptibility to penicillin, but any penicillin/gentamicin synergy is likely to be lost.

  2. Exposure of Salmonella enterica serovar Typhimurium to high level biocide challenge can select multidrug resistant mutants in a single step.

    Directory of Open Access Journals (Sweden)

    Rebekah N Whitehead

    Full Text Available Biocides are crucial to the prevention of infection by bacteria, particularly with the global emergence of multiply antibiotic resistant strains of many species. Concern has been raised regarding the potential for biocide exposure to select for antibiotic resistance due to common mechanisms of resistance, notably efflux.Salmonella enterica serovar Typhimurium was challenged with 4 biocides of differing modes of action at both low and recommended-use concentration. Flow cytometry was used to investigate the physiological state of the cells after biocide challenge. After 5 hours exposure to biocide, live cells were sorted by FACS and recovered. Cells recovered after an exposure to low concentrations of biocide had antibiotic resistance profiles similar to wild-type cells. Live cells were recovered after exposure to two of the biocides at in-use concentration for 5 hours. These cells were multi-drug resistant and accumulation assays demonstrated an efflux phenotype of these mutants. Gene expression analysis showed that the AcrEF multidrug efflux pump was de-repressed in mutants isolated from high-levels of biocide.These data show that a single exposure to the working concentration of certain biocides can select for mutant Salmonella with efflux mediated multidrug resistance and that flow cytometry is a sensitive tool for identifying biocide tolerant mutants. The propensity for biocides to select for MDR mutants varies and this should be a consideration when designing new biocidal formulations.

  3. High-Level Vancomycin-Resistant Staphylococcus aureus (VRSA in Iran: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Emran Askari

    2015-10-01

    Full Text Available Background: Staphylococcus aureus is a major human pathogen world- wide. Vancomycin has been used for decades to treat multidrug resistant S. aureus. Ten years has passed since the first report of vancomycin re- sistant S. aureus (VRSA. The objective of this systematic review was to determine  the total number of VRSA isolates that have been reported from Iran.Methods:  Search terms reflected “Iran”, “vancomycin” and “S. aureus” were  searched  in the ISI web  of knowledge,  PubMed,  SciVerse,  and Google scholar. Also two Persian scientific databases and 13 recent na- tional congresses  were investigated.  Articles / abstracts working on S. aureus in Iran, evaluating vancomycin MIC and / or PCR of vanA/B were included in this systematic review.Results: Out of the 3484 records found in mentioned resources, 13 re-lated studies were included in the final analysis. The result showed that at least 24 VRSA isolates which have been reported from Iran up to Sep- tember 2012.Conclusion: It seems that many Iranian researchers did not follow a spe- cific guideline for reporting and confirming VRSA. Establishing an Ira- nian reference center where studies on VRSA can be registered, evaluat- ed and confirmed is strongly recommended.

  4. Collateral Resistance and Sensitivity Modulate Evolution of High-Level Resistance to Drug Combination Treatment in Staphylococcus aureus

    DEFF Research Database (Denmark)

    de Evgrafov, Mari Cristina Rodriguez; Gumpert, Heidi; Munck, Christian

    2015-01-01

    As drug-resistant pathogens continue to emerge, combination therapy will increasingly be relied upon to treat infections and to help combat further development of multidrug resistance. At present a dichotomy exists between clinical practice, which favors therapeutically synergistic combinations......, and the scientific model emerging from in vitro experimental work, which maintains that this interaction provides greater selective pressure toward resistance development than other interaction types. We sought to extend the current paradigm, based on work below or near minimum inhibitory concentration levels......, to reflect drug concentrations more likely to be encountered during treatment. We performed a series of adaptive evolution experiments using Staphylococcus aureus. Interestingly, no relationship between drug interaction type and resistance evolution was found as resistance increased significantly beyond wild...

  5. Cluster of Neisseria gonorrhoeae Isolates With High-level Azithromycin Resistance and Decreased Ceftriaxone Susceptibility, Hawaii, 2016.

    Science.gov (United States)

    Katz, Alan R; Komeya, Alan Y; Kirkcaldy, Robert D; Whelen, A Christian; Soge, Olusegun O; Papp, John R; Kersh, Ellen N; Wasserman, Glenn M; O'Connor, Norman P; O'Brien, Pamela S; Sato, Douglas T; Maningas, Eloisa V; Kunimoto, Gail Y; Tomas, Juval E

    2017-09-15

    The Centers for Disease Control and Prevention (CDC) currently recommends dual therapy with ceftriaxone and azithromycin for gonorrhea to ensure effective treatment and slow emergence of antimicrobial resistance. Since 2013, the prevalence of reduced azithromycin susceptibility increased in the United States; however, these strains were highly susceptible to cephalosporins. We identified a cluster of Neisseria gonorrhoeae isolates with high-level azithromycin resistance, several of which also demonstrated decreased ceftriaxone susceptibility. Eight N. gonorrhoeae isolates collected from 7 patients on Oahu, Hawaii, seen 21 April 2016 through 10 May 2016 underwent routine Etest antimicrobial susceptibility testing by the Hawaii Department of Health. All demonstrated elevated azithromycin minimum inhibitory concentrations (MICs) >256 μg/mL and elevated ceftriaxone MICs (≥0.125 μg/mL). Isolates were sent to the University of Washington and CDC for confirmatory agar dilution testing; sequence data were sent to CDC for analysis. All patients were interviewed and treated, and when possible, partners were interviewed, tested, and treated. All isolates had azithromycin MICs >16 µg/mL and 5 had ceftriaxone MICs = 0.125 µg/mL by agar dilution. All isolates were β-lactamase positive and were resistant to penicillin, tetracycline, and ciprofloxacin. Genomic analysis revealed genetic relatedness. No patients reported recent travel or antibiotic use, and no male patients reported male sex partners. All patients were successfully treated. This cluster of genetically related gonococcal isolates with decreased ceftriaxone susceptibility and high-level azithromycin resistance may bring the threat of treatment failure in the United States with the current recommended dual therapy one step closer.

  6. Plasmid-mediated high-level gentamicin resistance among enteric bacteria isolated from pet turtles in Louisiana.

    Science.gov (United States)

    Díaz, María Alejandra; Cooper, Richard Kent; Cloeckaert, Axel; Siebeling, Ronald John

    2006-01-01

    The sale of small turtles is banned by the Food and Drug Administration from the U.S. market due to concerns about their excretion of Salmonella spp. To produce a safe pet for the export market, the Louisiana pet turtle industry uses gentamicin sulfate baths (1,000 microg/ml) to eradicate Salmonella spp. from turtle eggs. In 1999, we analyzed bacterial samples recovered from turtle farms and found that strains of Salmonella enterica subsp. arizonae and other bacteria, such as Enterobacter cloacae, Citrobacter freundii, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia, were resistant to high concentrations of gentamicin (>2,000 microg/ml) and to other aminoglycosides. The goal of this study was to identify the gene(s) which contributes to the high-level gentamicin resistance phenotype observed in bacteria from environmental samples with turtle farming activity, particularly the salmonellae, and to estimate the incidence of such genes in these bacteria. R plasmids from gentamicin-resistant strains were transferred by conjugation and transformation to naive Escherichia coli cells. Cloning and sequencing of the gentamicin resistance determinants on these plasmids revealed the presence of the aminoglycoside acetyltransferase genes aac(3)-IIa and aac(3)-VIa; the latter was present as a gene cassette of a class 1 integron. Multiplex PCR assays showed that every gentamicin-resistant isolate carried one of these acetyltransferase genes. Pulsed-field gel electrophoresis and restriction enzyme digestion analysis of R plasmids carrying these genes revealed different restriction profiles and sizes, indicating a dissemination of the gentamicin resistance genes through mobile molecular elements. The data presented highlight the need to develop an alternate method for the eradication of Salmonella spp. from turtle eggs.

  7. Interference in Pheromone-Responsive Conjugation of a High-Level Bacitracin Resistant Enterococcus faecalis Plasmid of Poultry Origin

    Science.gov (United States)

    Tremblay, Cindy-Love; Archambault, Marie

    2013-01-01

    The current study reports on contact interference of a high-level bacitracin- resistant pheromone-responsive plasmid of Enterococcus faecalis strain 543 of poultry origin during conjugative transfer of bcr antimicrobial resistance genes using a polyclonal antiserum aggregation substance44–560 (AS). After induction with pheromones produced by the recipient strain E. faecalis JH2-2, clumping of the donor E. faecalis strain 543 was observed as well as high transfer frequencies of bcr in short time broth mating. Filter mating assays from donor strain E. faecalis 543 to the recipient strain E. faecalis JH2-2 revealed conjugative transfer of asa1 (AS), bcrRAB and traB (negative regulator pheromone response) genes. The presence of these genes in transconjugants was confirmed by antimicrobial susceptibility testing, PCR, Southern hybridization and sequencing. A significant reduction in formation of aggregates was observed when the polyclonal anti-AS44–560 was added in the pheromone-responsive conjugation experiments as compared to the induced state. Moreover, interference of anti-AS44–560 antibodies in pheromone-responsive conjugation was demonstrated by a reduction in horizontal transfer of asa1 and bcr genes between E. faecalis strain 543 and E. faecalis JH2-2. Reducing the pheromone-responsive conjugation of E. faecalis is of interest because of its clinical importance in the horizontal transfer of antimicrobial resistance. PMID:24030654

  8. High-level resistance to class IIa bacteriocins is associated with one general mechanism in Listeria monocytogenes.

    Science.gov (United States)

    Gravesen, Anne; Ramnath, Manilduth; Rechinger, K Björn; Andersen, Natalie; Jänsch, Lothar; Héchard, Yann; Hastings, John W; Knøchel, Susanne

    2002-08-01

    Class IIa bacteriocins may be used as natural food preservatives, yet resistance development in the target organisms is still poorly understood. In this study, the understanding of class IIa resistance development in Listeria monocytogenes is extended, linking the seemingly diverging results previously reported. Eight resistant mutants having a high resistance level (at least a 10(3)-fold increase in MIC), originating from five wild-type listerial strains, were independently isolated following exposure to four different class IIa bacteriocin-producing lactic acid bacteria (including pediocin PA-1 and leucocin A producers). Two of the mutants were isolated from food model systems (a saveloy-type sausage at 10 degrees C, and salmon juice at 5 degrees C). Northern blot analysis showed that the eight mutants all had increased expression of EII(Bgl) and a phospho-beta-glucosidase homologue, both originating from putative beta-glucoside-specific phosphoenolpyruvate-dependent phosphotransferase systems (PTSs). However, disruption of these genes in a resistant mutant did not confer pediocin sensitivity. Comparative two-dimensional gel analysis of proteins isolated from mutant and wild-type strains showed that one spot was consistently missing in the gels from mutant strains. This spot corresponded to the MptA subunit of the mannose-specific PTS, found only in the gels of wild-type strains. The mptACD operon was recently shown to be regulated by the sigma(54) transcription factor in conjunction with the activator ManR. Class IIa bacteriocin-resistant mutants having defined mutations in mpt or manR also exhibited the two diverging PTS expression changes. It is suggested here that high-level class IIa resistance in L. monocytogenes and at least some other Gram-positive bacteria is developed by one prevalent mechanism, irrespective of wild-type strain, class IIa bacteriocin, or the tested environmental conditions. The changes in expression of the beta-glucoside-specific and

  9. Clinical features, risk factors and outcomes of bacteremia due to enterococci with high-level gentamicin resistance: comparison with bacteremia due to enterococci without high-level gentamicin resistance.

    Science.gov (United States)

    Jang, Hee-Chang; Lee, Shinwon; Song, Kyoung-Ho; Jeon, Jae Hyun; Park, Wan Beom; Park, Sang-Won; Kim, Hong Bin; Kim, Nam Joong; Kim, Eui-Chong; Oh, Myoung-Don; Choe, Kang Won

    2010-01-01

    High-level gentamicin resistance (HLGR) in enterococci has increased since the 1980s, but the clinical significance of the resistance and its impact on outcome have not been established. One hundred and thirty-six patients with bacteremia caused by enterococci with HLGR (HLGR group) were compared with 79 patients with bacteremia caused by enterococci without HLGR (non-HLGR group). Hematologic malignancy, neutropenia, Enterococcus faecium infection, nosocomial infection and monomicrobial bacteremia were more common in the HLGR group than the non-HLGR group, and APACHE II scores were also higher (P<0.05, in each case). Neutropenia, monomicrobial infection, stay in intensive care at culture, and use of 3rd generation cephalosporin, were independent risk factors for acquisition of HLGR enterococcal bacteremia. Fourteen-day and 30-day mortalities were higher in the HLGR group than the non-HLGR group in univariate analysis (37% vs. 15%, P=0.001; 50% vs. 22%, P<0.001). However, HLGR was not an independent risk factor for mortality due to enterococcal bacteremia in multivariate analysis. Therefore, HLGR enterococcal bacteremia is associated with more severe comorbid conditions and higher mortality than non-HLGR enterococcal bacteremia but the HLGR itself does not contribute significantly to mortality.

  10. Detection of the esp gene in high-level gentamicin resistant Enterococcus faecalis strains from pet animals in Japan.

    Science.gov (United States)

    Harada, Tetsuya; Tsuji, Noboru; Otsuki, Koichi; Murase, Toshiyuki

    2005-03-20

    We investigated the prevalence of the esp gene and the susceptibility to gentamicin in Enterococcus faecalis and E. faecium strains obtained from pet animals. Nine of 30 E. faecalis and 2 of 38 E. faecium strains from the pet animals had the esp gene. Three esp-positive E. faecalis strains, which were isolated from two dogs and a cat, showed gentamicin MICs of > or =256 microg/ml and harbored the high-level gentamicin resistance (HLGR) gene, aac(6')-Ie-aph(2'')-Ia. Of the nine esp-positive E. faecalis strains, five, including the three strains with the HLGR gene, were closely related by numerical analysis of PFGE patterns. Longitudinal investigation needs to elucidate whether the HLGR gene was incorporated into a subpopulation of the esp-positive E. faecalis.

  11. High-level Plasmodium falciparum sulfadoxine-pyrimethamine resistance with the concomitant occurrence of septuple haplotype in Tanzania.

    Science.gov (United States)

    Baraka, Vito; Ishengoma, Deus S; Fransis, Filbert; Minja, Daniel T R; Madebe, Rashid A; Ngatunga, Deogratius; Van Geertruyden, Jean-Pierre

    2015-11-05

    Tanzania abandoned sulfadoxine-pyrimethamine (SP) as the first-line treatment for uncomplicated malaria in 2006 due to high levels Plasmodium falciparum resistance. However, SP is still being used for intermittent preventive treatment during pregnancy (IPTp-SP). This study aimed to assess the pattern of P. falciparum dihydrofolate reductase (Pfdhfr) and dihydropteroate synthetase (Pfdhps) mutations and associated haplotypes in areas with different malaria transmission intensities in mainland Tanzania, 6 years after withdrawal of SP as a first-line treatment regimen for uncomplicated malaria. A total of 264 samples were collected during cross-sectional surveys in three districts of Muheza, Muleba and Nachingwea in Tanga, Kagera and Lindi regions, respectively. Parasite genomic DNA was extracted from P. falciparum positive samples. The Pfdhfr, Pfdhps single nucleotide polymorphisms (SNPs) were amplified using nested polymerase chain reaction and detected by sequence specific oligonucleotide probe-enzyme linked immunosorbent assay (SSOP-ELISA). The prevalence of the mutant Pfdhfr-Pfdhps haplotypes was heterogenous and transmission dependent. The triple Pfdhfr mutant haplotypes (CIRNI) were predominant in all sites with significantly higher frequencies at Muheza (93.3 %) compared to Muleba (75.0 %) and Nachingwea districts (70.6 %), (p haplotype was lowest at Muheza (1.3 %), (p = 0.002). Double Pfdhps haplotype SGEAA was significantly high at Muheza (27.2 %) and Muleba (20.8 %) while none (0 %) was detected at Nachingwea (p haplotype was significantly higher at Muheza compared to Muleba and Nachingwea (p haplotype (χ(2) = 39.9, p haplotypes were predominant including the emergence of a septuple mutant haplotype CIRNI-AGEGA (n = 11) observed at Muheza and Muleba. These results ascertain the high prevalence and saturation of Pfdhfr and Pfdhps haplotypes conferring SP resistance in areas with changing malaria epidemiology; and this could undermine the use of IPTp-SP in

  12. High-Level Ciprofloxacin-Resistant Campylobacter jejuni Isolates Circulating in Humans and Animals in Incheon, Republic of Korea.

    Science.gov (United States)

    Kim, J S; Lee, M Y; Kim, S J; Jeon, S-E; Cha, I; Hong, S; Chung, G T; Huh, M-J; Kang, Y-H; Yoo, C-K; Kim, J

    2016-11-01

    Campylobacter jejuni is one of the major causative pathogens of outbreaks or sporadic cases of diarrhoeal diseases worldwide. In this study, we compared the phenotypic and genetic characteristics of C. jejuni isolates of human and food-producing animal origins in Korea and examined the genetic relatedness between these two groups of isolates. Regardless of isolation source, all C. jejuni isolates harboured four virulence genes, cadF, cdtB, ciaB and racR, whereas the wlaN and virB11 genes were more frequently observed in human isolates. Antimicrobial susceptibility testing showed that the majority of C. jejuni isolates displayed high-level resistance to fluoroquinolone (95.2%) or tetracycline (76.2%) antibiotics, and 12.4% of isolates exhibited multidrug resistance (more than three classes of antibiotics tested). Pulsed-field gel electrophoresis (PFGE) of all Campylobacter isolates revealed 51 different SmaI-PFGE patterns and six major clusters containing both human and animal isolates. These results indicate that genetically diverse strains of C. jejuni with antimicrobial drug-resistance and virulence properties have prevailed in Incheon. Nevertheless, some particular populations continue to circulate within the community, providing the evidence for an epidemiological link of C. jejuni infections between humans and food-producing animals. Therefore, the continued monitoring and surveillance of C. jejuni isolates of human and food-producing animal origins are required for public health and food safety. © 2016 Blackwell Verlag GmbH.

  13. [Emergence of high-level resistance to gentamicin and streptomycin in Streptococcus agalactiae in Buenos Aires, Argentina].

    Science.gov (United States)

    Villar, Hugo Edgardo; Jugo, Mónica Beatriz

    2013-06-01

    Streptococcus agalactiae has become recognized as a cause of serious illness in newborns, pregnant women, and adults with chronic medical conditions. Optimal antimicrobial therapy for serious infections requires the use of synergistic combinations of a cell wall-active agent, such as a penicillin, with an aminoglycoside, which results in bactericidal activity against this organism. The synergistic effect is eliminated by the acquisition of high-level resistance (HLR) to aminoglycosides. The aim of our study was to determine the prevalence of HLR to gentamicin (GEN) and streptomycin (EST).The ability to detect HLR using a standard agar screen plate and high-content discs was investigated. This study was conducted with 141 strains of S. agalactiae isolated from vaginal and rectal swabs of pregnant women at term. Minimum inhibitory concentrations (MICs) to GEN and STR were determined by the E-test method. Disks of GEN (120 μg) and STR (300 μg) were used to detect HLR. Agar screening plates were performed with GEN 100 mg/L, GEN 500 mg/L and STR 2000 mg/L. The HLR to GEN and STR was detected in 13.5% and 16.3% of the isolates respectively. Among 141 strains, 7.8% were simultaneously resistant to GEN and STR. With 120-μg GEN and 300-μg STR disks, strains for which MICs were ≥ 512 mg/L and ≥ 1024 mg/L had no zones of inhibition. Isolates with inhibitory zones for GEN and STR of ≥13 mm showed a MICs ≤ 64 mg/L and ≤ 512 mg/L. All the screening plates were negative for these isolates. HLR to aminoglycosides was associated (83.9%) with resistance to erythromycin and/or clindamycin. This study highlights the emergence of strains with HLR to aminoglycosides. The disk-agar diffusion test performed with high-content aminoglycoside disks and screening plates can provide laboratories with a convenient and reliable method for detecting S. agalactiae isolates that are resistant to aminoglycoside-betalactam synergy.

  14. Comparative Study of Bacteremias Caused by Enterococcus spp. with and without High-Level Resistance to Gentamicin

    Science.gov (United States)

    Caballero-Granado, Francisco Javier; Cisneros, J. M.; Luque, R.; Torres-Tortosa, M.; Gamboa, F.; Díez, F.; Villanueva, J. L.; Pérez-Cano, R.; Pasquau, J.; Merino, D.; Menchero, A.; Mora, D.; López-Ruz, M. A.; Vergara, A.; Infecciosas, for the Grupo Andaluz Para El Estudio De Las Enfermedades

    1998-01-01

    A prospective, multicenter study was carried out over a period of 10 months. All patients with clinically significant bacteremia caused by Enterococcus spp. were included. The epidemiological, microbiological, clinical, and prognostic features and the relationship of these features to the presence of high-level resistance to gentamicin (HLRG) were studied. Ninety-three patients with enterococcal bacteremia were included, and 31 of these cases were caused by HLRG (33%). The multivariate analysis selected chronic renal failure, intensive care unit stay, previous use of antimicrobial agents, and Enterococcus faecalis species as the independent risk factors that influenced the development of HLRG. The strains with HLRG showed lower levels of susceptibility to penicillin and ciprofloxacin. Clinical features (except for chronic renal failure) were similar in both groups of patients. HLRG did not influence the prognosis for patients with enterococcal bacteremia in terms of either the crude mortality rate (29% for patients with bacteremia caused by enterococci with HLRG and 28% for patients not infected with strains with HLRG) or the hospital stay after the acquisition of enterococcal bacteremia. Hemodynamic compromise, inappropriate antimicrobial therapy, and mechanical ventilation were revealed in the multivariate analysis to be the independent risk factors for mortality. Prolonged hospitalization was associated with the nosocomial acquisition of bacteremia and polymicrobial infections. PMID:9466769

  15. Increasing Incidence of High-Level Tetracycline-Resistant Neisseria gonorrhoeae due to Clonal Spread and Foreign Import.

    Science.gov (United States)

    Lee, Hyukmin; Kim, Hyunsoo; Kim, Hyo Jin; Suh, Young Hee; Yong, Dongeun; Jeong, Seok Hoon; Lee, Kyungwon; Chong, Yunsop

    2016-03-01

    The detection of high-level tetracycline-resistant strains of Neisseria gonorrhoeae (TRNG) can make important epidemiological contributions that are relevant to controlling infections from this pathogen. In this study, we aimed to determine the incidence of TRNG isolates over time and also to investigate the characteristics and genetic epidemiology of these TRNG isolates in Korea. The antimicrobial susceptibilities of 601 isolates of N. gonorrhoeae from 2004 to 2011 were tested by standard Clinical and Laboratory Standards Institute methods. To determine the molecular epidemiological relatedness, N. gonorrhoeae multi-antigen sequence typing was performed. The incidence of TRNG increased from 2% in 2004 to 21% in 2011. The minimum inhibitory concentration distributions of ceftriaxone and susceptibility of ciprofloxacin in TRNG were different from non-TRNG and varied according to the year of isolation. Most of the TRNG isolates collected from 2004 to 2007 exhibited genetic relatedness, with sequence type (ST) 1798 being the most common. From 2008 to 2011, the STs of the isolates became more variable and introduction of genetically unrelated TRNG were noted. The increased incidence of TRNG strains until 2007 appears to be due, at least in part, to clonal spread. However, we propose that the emergence of various STs since 2008 could be associated with foreign import.

  16. Characterization of antimicrobial resistance and quinolone resistance factors in high-level ciprofloxacin-resistant Enterococcus faecalis and Enterococcus faecium isolates obtained from fresh produce and fecal samples of patients.

    Science.gov (United States)

    Kim, Min-Chan; Woo, Gun-Jo

    2017-07-01

    The emergence of fluoroquinolone-resistant enterococci is worldwide. Antimicrobial resistance was characterized and the effect of quinolone-resistance factors was analyzed in high-level ciprofloxacin-resistant (HLCR) Enterococcus faecalis and Enterococcus faecium isolated from fresh produce and fecal samples of patients. Among the 81 ciprofloxacin-resistant Enterococcus isolates, 46 showed high levels of ciprofloxacin resistance, resistance to other quinolone antibiotics, and multidrug resistance profiles. The virulence factors esp and hyl were identified in 27 (58.7%) and 25 (54.3%) of isolates, respectively. Sequence type analysis showed that 35 strains of HLCR E. faecium were clonal complex 17. Eleven strains of HLCR E. faecalis were confirmed as sequence type (ST) 28, ST 64 and ST 125. Quinolone resistance-determining region mutation was identified in HLCR Enterococcus isolates; with serine being changed in gyrA83, gyrA87 and parC80. This result shows that gyrA and parC mutations could be important factors for high-level resistance to fluoroquinolones. No significant differences were observed in antimicrobial resistance patterns and genetic characteristics among the isolates from fresh produce and fecal samples. Therefore, good agricultural practices in farming and continuous monitoring of patients, food and the environment for Enterococcus spp. should be performed to prevent antimicrobial resistance and enable reduction of resistance rates. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  17. High-level resistance to gentamicin: genetic transfer between Enterococcus faecalis isolated from food of animal origin and human microbiota.

    Science.gov (United States)

    Sparo, M; Urbizu, L; Solana, M V; Pourcel, G; Delpech, G; Confalonieri, A; Ceci, M; Sánchez Bruni, S F

    2012-02-01

      To investigate the in vivo gene transfer of high-level gentamicin resistance (HLRG) from Enterococcus faecalis isolated from the food of animal origin to a human isolate, using a mouse model of intestinally colonized human microbiota.   In vitro study: The presence of plasmids involved in HLRG coding was investigated. After the conjugation experiment, the recipient strain, Ent. faecalis JH2-SS, acquired a plasmid responsible for HLRG [minimal inhibitory concentration (MIC) >800 μg ml(-1) ], in a similar position to the donor cells. In vivo study: Seven BALB/c mice were dosed with ceftriaxone (400 mg kg(-1) ) and then inoculated with a dilution of 1/100 of human faeces (HFc). After 72 h, Ent. faecalis JH2-SS (recipient) was inoculated and then, after a further 72 h, the animals were given Ent. faecalis CS19, isolated from the food of animal origin, involved in HLRG (donor). The presence of transconjugant strains in HFc was subsequently recorded on a daily basis until the end of the experiment. The clonal relationship between Ent. faecalis and Escherichia coli in faeces was assessed by RAPD-PCR. Both the in vitro and in vivo studies showed that the receptor strain acquired a plasmid responsible for HLRG (MICs >800 μg ml(-1) ), which migrated with a similar relative mobility value. Transconjugant strains were detected from 24 h after the donor strain inoculation and persisted until the end of the experiment.   The in vivo gene transfer of HLRG from Ent. faecalis strains, isolated from the food of animal origin, to human microbiota has been demonstrated in a mouse model.   The complexity found on the therapeutic responses of invasive infectious diseases caused by Ent. faecalis facilitates the assessment of food of animal origin as a resistant pathogen reservoir. In addition, this study may contribute to the understanding of antimicrobials' resistance gene transfer between Ent. faecalis strains from food and human GI tract. © 2011 The Authors. Letters in

  18. Evidence of Nosocomial Infection in Japan Caused by High-Level Gentamicin-Resistant Enterococcus faecalis and Identification of the Pheromone-Responsive Conjugative Plasmid Encoding Gentamicin Resistance

    Science.gov (United States)

    Ma, Xinghua; Kudo, Michiaki; Takahashi, Ayako; Tanimoto, Koichi; Ike, Yasuyoshi

    1998-01-01

    A total of 1,799 Enterococcus faecalis isolates were isolated from inpatients of Gunma University Hospital, Gunma, Japan, between 1992 and 1996. Four hundred thirty-two (22.3%) of the 1,799 isolates had high-level gentamicin resistance. Eighty-one of the 432 isolates were classified and were placed into four groups (group A through group D) with respect to the EcoRI restriction endonuclease profiles of the plasmid DNAs isolated from these strains. The 81 isolates were isolated from 36 patients. For 35 of the 36 patients, the same gentamicin-resistant isolates were isolated from the same or different specimens isolated from the same patient at different times during the hospitalization. For one other patient, two different groups of the isolates were isolated from the same specimen. Groups A, B, C, and D were isolated from 5, 14, 12, and 6 patients, respectively. The strains had multiple-drug resistance. The restriction endonuclease digestion patterns of the E. faecalis chromosomal DNAs isolated from isolates in the same group were also identical. The patients who had been infected with the gentamicin-resistant isolates from each group were geographically clustered on a ward(s). These results suggest that the isolates in each group were derived from a common source and had spread in the ward. The gentamicin-resistant isolates exhibited a clumping response upon exposure to pheromone (E. faecalis FA2-2 culture filtrate). The gentamicin resistance transferred at a high frequency to the recipient E. faecalis isolates by broth mating, and the pheromone-responsive plasmids encoding the gentamicin resistance were identified in these isolates. PMID:9705374

  19. Sublethal Ciprofloxacin Treatment Leads to Rapid Development of High-Level Ciprofloxacin Resistance during Long-Term Experimental Evolution of Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Jørgensen, Karin Meinike; Wassermann, Tina; Jensen, Peter Østrup

    2013-01-01

    lineages after 240 generations. The genetic basis of resistance was mutations in gyrA (C248T and G259T) and gyrB (C1397A). Cross-resistance to beta-lactam antibiotics was observed in the bacterial populations that evolved during exposure to sublethal concentrations of ciprofloxacin. Our study shows...... that mutants with high-level ciprofloxacin resistance are selected in P. aeruginosa bacterial populations exposed to sub-MICs of ciprofloxacin. This can have implications for the long-term persistence of resistant bacteria and spread of antibiotic resistance by exposure of commensal bacterial flora to low...

  20. Phenotypic and molecular characterization of Staphylococcus aureus isolates expressing low- and high-level mupirocin resistance in Nigeria and South Africa

    Directory of Open Access Journals (Sweden)

    Udo Edet E

    2009-01-01

    Full Text Available Abstract Background Mupirocin is a topical antimicrobial agent which is used for the treatment of skin and postoperative wound infections, and the prevention of nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA. However, the prevalence of mupirocin resistance in S. aureus, particularly in MRSA, has increased with the extensive and widespread use of this agent in hospital settings. This study characterized low- and high-level mupirocin-resistant S. aureus isolates obtained from Nigeria and South Africa. Methods A total of 17 mupirocin-resistant S. aureus isolates obtained from two previous studies in Nigeria and South Africa, were characterized by antibiogram, PCR-RFLP of the coagulase gene and PFGE. High-level mupirocin resistant isolates were confirmed by PCR detection of the mupA gene. The genetic location of the resistance determinants was established by curing and transfer experiments. Results All the low-level mupirocin resistant isolates were MRSA and resistant to gentamicin, tetracycline and trimethoprim. PFGE identified a major clone in two health care institutions located in Durban and a health care facility in Pietermaritzburg, Greytown and Empangeni. Curing and transfer experiments indicated that high-level mupirocin resistance was located on a 41.1 kb plasmid in the South African strain (A15. Furthermore, the transfer of high-level mupirocin resistance was demonstrated by the conjugative transfer of the 41.1 kb plasmid alone or with the co-transfer of a plasmid encoding resistance to cadmium. The size of the mupirocin-resistance encoding plasmid in the Nigerian strain (35 IBA was approximately 35 kb. Conclusion The emergence of mupirocin-resistant S. aureus isolates in Nigeria and South Africa should be of great concern to medical personnel in these countries. It is recommended that methicillin-susceptible S. aureus (MSSA and MRSA should be routinely tested for mupirocin resistance even in facilities where the agent

  1. Novel plasmids and resistance phenotypes in Yersinia pestis: unique plasmid inventory of strain Java 9 mediates high levels of arsenic resistance.

    Directory of Open Access Journals (Sweden)

    Mark Eppinger

    Full Text Available Growing evidence suggests that the plasmid repertoire of Yersinia pestis is not restricted to the three classical virulence plasmids. The Java 9 strain of Y. pestis is a biovar Orientalis isolate obtained from a rat in Indonesia. Although it lacks the Y. pestis-specific plasmid pMT, which encodes the F1 capsule, it retains virulence in mouse and non-human primate animal models. While comparing diverse Y. pestis strains using subtractive hybridization, we identified sequences in Java 9 that were homologous to a Y. enterocolitica strain carrying the transposon Tn2502, which is known to encode arsenic resistance. Here we demonstrate that Java 9 exhibits high levels of arsenic and arsenite resistance mediated by a novel promiscuous class II transposon, named Tn2503. Arsenic resistance was self-transmissible from Java 9 to other Y. pestis strains via conjugation. Genomic analysis of the atypical plasmid inventory of Java 9 identified pCD and pPCP plasmids of atypical size and two previously uncharacterized cryptic plasmids. Unlike the Tn2502-mediated arsenic resistance encoded on the Y. enterocolitica virulence plasmid; the resistance loci in Java 9 are found on all four indigenous plasmids, including the two novel cryptic plasmids. This unique mobilome introduces more than 105 genes into the species gene pool. The majority of these are encoded by the two entirely novel self-transmissible plasmids, which show partial homology and synteny to other enterics. In contrast to the reductive evolution in Y. pestis, this study underlines the major impact of a dynamic mobilome and lateral acquisition in the genome evolution of the plague bacterium.

  2. Molecular screening of virulence genes in high-level gentamicin-resistant Enterococcus faecalis and Enterococcus faecium isolated from clinical specimens in Northwest Iran.

    Science.gov (United States)

    Hasani, A; Sharifi, Y; Ghotaslou, R; Naghili, B; Hasani, A; Aghazadeh, M; Milani, M; Bazmani, A

    2012-01-01

    The present study screened clinical isolates of Enterococcus faecalis and Enterococcus faecium to determine the prevalence of high-level gentamicin-resistant enterococci and the potential virulence genes among them. Clinical enterococcal isolates were obtained from three university teaching hospitals in Northwest Iran. Isolated enterococci were identified phenotypically followed by antibiotic susceptibility testing. Multiplex PCR was performed for the detection of genus, species-specific targets, gentamicin resistance, and potential virulence genes. Of 220 enterococcal isolates, 133 (60.45%) isolates were identified as high-level gentamicin-resistant. Of these isolates, 79 (59.4%) and 54 (40.6%) were E. faecalis and E. faecium, respectively. All high-level gentamicin-resistant strains carried aac(6')Ie-aph(2″)Ia. Of 220 isolates, 65.9% were positive for gelE, and 55%, 53.6%, 51.8%, and 49.5% of isolates were positive for cpd, asa1, ace, and esp, respectively. Phenotypically detected β-haemolytic strains (19.54%) were found to possess cylL ls MAB. The study revealed that high-level gentamicin-resistance was related to the presence of aac(6')Ie-aph(2″)Ia. Isolated enterococci harboured potential virulence determinants, which were more common among E. faecalis than among E. faecium strains.

  3. Prevalence of high level gentamicin and vancomycin resistance among clinical isolates of enterococci from a tertiary care hospital in central Nepal.

    Science.gov (United States)

    Amatya, R; Jha, B; Shrestha, S; Adhikari, R P; Timsina, S

    2014-12-01

    High level aminoglycoside resistance is an established phenomenon in enterococci. With the increasing use of broad spectrum cephalosporins and glycopeptides, vancomycin resistant enterococci are being increasingly reported from different parts of the world. The objective of our study was to determine the prevalence of high level gentamicin resistant (HLAR) enterococci among the clinical isolates in our hospital and to find the minimum inhibitory concentration (MIC) of vancomycin against these isolates. The enterococci isolated over a year (n = 41) were subjected to HLAR screening by disc diffusion and MIC of vancomycin by agar dilution method. HLAR prevalence was 63%. MIC of vancomycin showed none in the resistant range. However, 4 (9.7%) isolates were in the intermediate range heralding the eminent emergence of VRE if adequate control measures are not implemented in time.

  4. Inheritance of high levels of resistance to common bacterial blight caused by Xanthomonas Axonopodis pv. Phaseoli in common bean (Phaseolus vulgaris L.)

    Science.gov (United States)

    Common bacterial blight caused by the pathogen Xanthomonas axonopodis pv. phaseoli (Xap) is an important biotic factor limiting common bean (Phaseolus vulgaris L.) production. A few interspecific bean breeding lines such as VAX 6 exhibit a high level of resistance to a wide range of Xap strains repr...

  5. vanA Gene Harboring Enterococcal and Non-enterococcal Isolates Expressing High Level Vancomycin and Teicoplanin Resistance Reservoired in Surface Waters.

    Science.gov (United States)

    Nakipoğlu, Mustafa; Yilmaz, Fadime; Icgen, Bulent

    2017-05-01

    Untreated wastewaters and treated effluents even after final disinfection contain antibiotic resistant bacteria and resistance genes before they are released into surface waters. A correlation between resistant bacteria and antibiotics in surface waters has been found, as have antibiotic resistance genes. Of particular interest are vancomycin-resistant enterococci harboring vanA gene that confers high level of resistance to glycopeptide antibiotics including teicoplanin. Therefore, in this study, river water samples were analysed to investigate vancomycin- and teicoplanin-resistant bacterial isolates harboring vanA gene. Out of 290, 15 surface water isolates displayed resistance to both antibiotics. These glycopeptide resistant enterococcal and non-enterococcal isolates, identified by 16S rRNA sequencing, were found to harbor vanA gene with sequence similarities of 50 % to 100 %. The presence of D-alanine-D-lactate ligase encoded by vanA gene was also shown for all vancomycin- and teicoplanin-resistant isolates through western blot analysis. Due to reuse of treated wastewater and release of untreated wastewaters to water bodies, antibiotic resistant bacteria and resistance genes are being introduced into surface waters and present human health risks. Therefore, surface waters are not only hot spots for vanA harboring enterococcal isolates but also non-enterococcal isolates due to gene dissemination and require special scientific consideration.

  6. Mutation (G275E) of the nicotinic acetylcholine receptor α6 subunit is associated with high levels of resistance to spinosyns in Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae).

    Science.gov (United States)

    Silva, Wellington M; Berger, Madeleine; Bass, Chris; Williamson, Martin; Moura, Danielle M N; Ribeiro, Lílian M S; Siqueira, Herbert A A

    2016-07-01

    The tomato leafminer, Tuta absoluta, now a major pest of tomato crops worldwide, is primarily controlled using chemical insecticides. Recently, high levels of resistance to the insecticide spinosad have been described in T. absoluta populations in Brazil. Selection of a resistant field-collected strain led to very high levels of resistance to spinosad and cross-resistance to spinetoram, but not to other insecticides that target the nicotinic acetylcholine receptor (nAChR). In this study the mechanisms underlying resistance to spinosad were investigated using toxicological, biochemical and molecular approaches. Inhibition of metabolic enzymes using synergists and biochemical assessment of detoxification enzyme activity provided little evidence of metabolic resistance in the selected strain. Cloning and sequencing of the nAChR α6 subunit from T. absoluta, the spinosad target-site, from susceptible and spinosad-resistant strains were done to investigate the role of a target-site mechanism in resistance. A single nucleotide change was identified in exon 9 of the α6 subunit of the resistant strain, resulting in the replacement of the glycine (G) residue at position 275 observed in susceptible T. absoluta strains with a glutamic acid (E). A high-throughput DNA-based diagnostic assay was developed and used to assess the prevalence of the G275E mutation in 17 field populations collected from different geographical regions of Brazil. The resistant allele was found at low frequency, and in the heterozygous form, in seven of these populations but at much higher frequency and in the homozygous form in a population collected in the Iraquara municipality. The frequency of the mutation was significantly correlated with the mortality of these populations in discriminating dose bioassays. In summary our results provide evidence that the G275E mutation is an important mechanism of resistance to spinosyns in T. absoluta, and may be used as a marker for resistance monitoring in

  7. Genetic relatedness and risk factor analysis of ampicillin-resistant and high-level gentamicin-resistant enterococci causing bloodstream infections in Tanzanian children.

    Science.gov (United States)

    Aamodt, Håvard; Mohn, Stein Christian; Maselle, Samuel; Manji, Karim P; Willems, Rob; Jureen, Roland; Langeland, Nina; Blomberg, Bjørn

    2015-02-28

    While enterococci resistant to multiple antimicrobials are spreading in hospitals worldwide, causing urinary tract, wound and bloodstream infections, there is little published data on these infections from Africa. We assessed the prevalence, susceptibility patterns, clinical outcome and genetic relatedness of enterococcal isolates causing bloodstream infections in children in a tertiary hospital in Tanzania, as part of a prospective cohort study of bloodstream infections among 1828 febrile children admitted consecutively from August 2001 to August 2002. Enterococcal bacteraemia was identified in 2.1% (39/1828) of admissions, and in 15.3% (39/255) of cases of culture-confirmed bloodstream infections. The case-fatality rate in children with Enterococcus faecalis septicaemia (28.6%, 4/14) was not significantly different from those with Enterococcus faecium septicaemia (6.7%, 1/15, p = 0.12). E. faecium isolates commonly had combined ampicillin-resistance and high-level gentamicin resistance (HLGR), (9/17), while E. faecalis frequently displayed HLGR (6/15), but were ampicillin susceptible. None of the tested enterococcal isolates displayed vancomycin resistance by Etest or PCR for vanA and vanB genes. Multi-locus sequence-typing (MLST) showed that the majority of E. faecium (7/12) belonged to the hospital associated Bayesian Analysis of Population Structure (BAPS) group 3-3. Pulsed-field gel electrophoresis (PFGE) indicated close genetic relationship particularly among E. faecium isolates, but also among E. faecalis isolates. There was also correlation between BAPS group and PFGE results. Risk factors for enterococcal bloodstream infection in univariate analysis were hospital-acquired infection and clinical diagnosis of sepsis with unknown focus. In multivariate analysis, neonates in general were relatively protected from enterococcal infection, while both prematurity and clinical sepsis were risk factors. Malnutrition was a risk factor for enterococcal

  8. High-level plasmid-mediated gentamicin resistance and pheromone response of plasmids present in clinical isolates of Enterococcus faecalis.

    OpenAIRE

    Shiojima, M; Tomita, H; Tanimoto, K; Fujimoto, S; Ike, Y

    1997-01-01

    Eleven pheromone-responding plasmids encoding erythromycin or gentamicin resistance were isolated from multiresistant clinical Enterococcus faecalis isolates. The plasmids were classified into six types with respect to their pheromone responses. The three erythromycin resistance plasmids responded to different pheromones. Of the eight gentamicin resistance plasmids, four plasmids responded to same pheromone. Southern hybridization studies showed that the genes involved in regulation of the ph...

  9. High-Level Cefixime- and Ceftriaxone-Resistant Neisseria gonorrhoeae in France: Novel penA Mosaic Allele in a Successful International Clone Causes Treatment Failure

    Science.gov (United States)

    Golparian, Daniel; Nicholas, Robert; Ohnishi, Makoto; Gallay, Anne; Sednaoui, Patrice

    2012-01-01

    Recently, the first Neisseria gonorrhoeae strain (H041) highly resistant to the expanded-spectrum cephalosporins (ESCs) ceftriaxone and cefixime, which are the last remaining options for first-line gonorrhea treatment, was isolated in Japan. Here, we confirm and characterize a second strain (F89) with high-level cefixime and ceftriaxone resistance which was isolated in France and most likely caused a treatment failure with cefixime. F89 was examined using six species-confirmatory tests, antibiograms (33 antimicrobials), porB sequencing, N. gonorrhoeae multiantigen sequence typing (NG-MAST), multilocus sequence typing (MLST), and sequencing of known gonococcal resistance determinants (penA, mtrR, penB, ponA, and pilQ). F89 was assigned to MLST sequence type 1901 (ST1901) and NG-MAST ST1407, which is a successful gonococcal clone that has spread globally. F89 has high-level resistance to cefixime (MIC = 4 μg/ml) and ceftriaxone (MIC = 1 to 2 μg/ml) and resistance to most other antimicrobials examined. A novel penA mosaic allele (penA-CI), which was penA-XXXIV with an additional A501P alteration in penicillin-binding protein 2, was the primary determinant for high-level ESC resistance, as determined by transformation into a set of recipient strains. N. gonorrhoeae appears to be emerging as a superbug, and in certain circumstances and settings, gonorrhea may become untreatable. Investigations of the biological fitness and enhanced understanding and monitoring of the ESC-resistant clones and their international transmission are required. Enhanced disease control activities, antimicrobial resistance control and surveillance worldwide, and public health response plans for global (and national) perspectives are also crucial. Nevertheless, new treatment strategies and/or drugs and, ideally, a vaccine are essential to develop for efficacious gonorrhea management. PMID:22155830

  10. Evolution of a Double Amino Acid Substitution in the 5-Enolpyruvylshikimate-3-Phosphate Synthase in Eleusine indica Conferring High-Level Glyphosate Resistance1

    Science.gov (United States)

    Yu, Qin; Jalaludin, Adam; Han, Heping; Chen, Ming; Sammons, R. Douglas; Powles, Stephen B.

    2015-01-01

    Glyphosate is the most important and widely used herbicide in world agriculture. Intensive glyphosate selection has resulted in the widespread evolution of glyphosate-resistant weed populations, threatening the sustainability of this valuable once-in-a-century agrochemical. Field-evolved glyphosate resistance due to known resistance mechanisms is generally low to modest. Here, working with a highly glyphosate-resistant Eleusine indica population, we identified a double amino acid substitution (T102I + P106S [TIPS]) in the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene in glyphosate-resistant individuals. This TIPS mutation recreates the biotechnology-engineered commercial first generation glyphosate-tolerant EPSPS in corn (Zea mays) and now in other crops. In E. indica, the naturally evolved TIPS mutants are highly (more than 180-fold) resistant to glyphosate compared with the wild type and more resistant (more than 32-fold) than the previously known P106S mutants. The E. indica TIPS EPSPS showed very high-level (2,647-fold) in vitro resistance to glyphosate relative to the wild type and is more resistant (600-fold) than the P106S variant. The evolution of the TIPS mutation in crop fields under glyphosate selection is likely a sequential event, with the P106S mutation being selected first and fixed, followed by the T102I mutation to create the highly resistant TIPS EPSPS. The sequential evolution of the TIPS mutation endowing high-level glyphosate resistance is an important mechanism by which plants adapt to intense herbicide selection and a dramatic example of evolution in action. PMID:25717039

  11. Identification of QTL controlling high levels of partial resistance to Fusarium solani f. sp. pisi in pea

    Science.gov (United States)

    Fusarium root rot is a common biotic restraint on pea yields worldwide and genetic resistance is the most feasible method for improving pea production. This study was conducted to discover quantitative trait loci (QTL) controlling genetic partial resistance to Fusarium root rot caused by Fusarium s...

  12. Complete genome sequence of Enterobacter cloacae R11 reveals multiple genes potentially associated with high-level polymyxin E resistance.

    Science.gov (United States)

    Zhong, Chuanqing; Zhang, Chao; Fu, Jiafang; Chen, Wenbing; Jiang, Tianyi; Cao, Guangxiang

    2018-01-01

    Enterobacter cloacae strain R11 is a multidrug-resistant bacterium isolated from sewage water near a swine feedlot in China. Strain R11 can survive in medium containing up to 192 μg/mL polymyxin E, indicating a tolerance for this antibiotic that is significantly higher than that reported for other gram-negative bacteria. In this study, conjugation experiments showed that partial polymyxin E resistance could be transferred from strain R11 to Escherichia coli strain 25922, revealing that some genes related to polymyxin E resistance are plasmid-based. The complete genome sequence of this strain was determined, yielding a total of 4 993 008 bp (G+C content, 53.15%) and 4908 genes for the circular chromosome and 4 circular plasmids. Genome analysis revealed a total of 73 putative antibiotic resistance genes, including several polymyxin E resistance genes and genes potentially involved in multidrug resistance. These data provide insights into the genetic basis of the polymyxin E resistance and multidrug resistance of E. cloacae.

  13. Vip3A resistance alleles exist at high levels in Australian targets before release of cotton expressing this toxin.

    Directory of Open Access Journals (Sweden)

    Rod J Mahon

    Full Text Available Crops engineered to produce insecticidal crystal (Cry proteins from the soil bacterium Bacillus thuringiensis (Bt have revolutionised pest control in agriculture. However field-level resistance to Bt has developed in some targets. Utilising novel vegetative insecticidal proteins (Vips, also derived from Bt but genetically distinct from Cry toxins, is a possible solution that biotechnical companies intend to employ. Using data collected over two seasons we determined that, before deployment of Vip-expressing plants in Australia, resistance alleles exist in key targets as polymorphisms at frequencies of 0.027 (n = 273 lines, 95% CI = 0.019-0.038 in H. armigera and 0.008 (n = 248 lines, 0.004-0.015 in H. punctigera. These frequencies are above mutation rates normally encountered. Homozygous resistant neonates survived doses of Vip3A higher than those estimated in field-grown plants. Fortunately the resistance is largely, if not completely, recessive and does not confer resistance to the Bt toxins Cry1Ac or Cry2Ab already deployed in cotton crops. These later characteristics are favourable for resistance management; however the robustness of Vip3A inclusive varieties will depend on resistance frequencies to the Cry toxins when it is released (anticipated 2016 and the efficacy of Vip3A throughout the season. It is appropriate to pre-emptively screen key targets of Bt crops elsewhere, especially those such as H. zea in the USA, which is not only closely related to H. armigera but also will be exposed to Vip in several varieties of cotton and corn.

  14. High-Level Resistance of Staphylococcus aureus to β-Lactam Antibiotics Mediated by Penicillin-Binding Protein 4 (PBP4).

    Science.gov (United States)

    Hamilton, Stephanie M; Alexander, J Andrew N; Choo, Eun Ju; Basuino, Li; da Costa, Thaina M; Severin, Anatoly; Chung, Marilyn; Aedo, Sandra; Strynadka, Natalie C J; Tomasz, Alexander; Chatterjee, Som S; Chambers, Henry F

    2017-06-01

    Penicillin-binding protein 4 (PBP4), a nonessential, low-molecular-weight penicillin-binding protein of Staphylococcus aureus, has been implicated in low-level resistance to β-lactam antibiotics, although the mechanism is unknown. Mutations in PBP4 and its promoter were identified in a laboratory-generated mutant strain, CRB, which expresses high-level resistance to β-lactams, including resistance to the new-generation cephalosporins active against methicillin-resistant strains of S. aureus These mutations did not appreciably alter the β-lactam antibiotic binding affinity of purified recombinant mutant PBP4 compared to that of wild-type PBP4. Compared to the susceptible parent strain, COLnex, the CRB strain produces a highly cross-linked cell wall peptidoglycan, indicative of increased transpeptidase activity. The pbp4 promoter mutation of CRB was associated with greatly increased amounts of PBP4 in membranes compared to those in the COLnex parent. Replacement of the native promoter of COLnex with the mutant promoter of CRB resulted in increased amounts of PBP4 in membranes and a highly cross-linked cell wall. PBP4 can be repurposed to provide essential transpeptidase activity in vivo and confer high-level resistance to β-lactam antibiotics, such as ceftobiprole and ceftaroline. Copyright © 2017 American Society for Microbiology.

  15. GLUT4 content decreases along with insulin resistance and high levels of inflammatory markers in rats with metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Leguisamo Natalia M

    2012-08-01

    Full Text Available Abstract Background Metabolic syndrome is characterized by insulin resistance, which is closely related to GLUT4 content in insulin-sensitive tissues. Thus, we evaluated the GLUT4 expression, insulin resistance and inflammation, characteristics of the metabolic syndrome, in an experimental model. Methods Spontaneously hypertensive neonate rats (18/group were treated with monosodium glutamate (MetS during 9 days, and compared with Wistar-Kyoto (C and saline-treated SHR (H. Blood pressure (BP and lipid levels, C-reactive protein (CRP, interleukin 6 (IL-6, TNF-α and adiponectin were evaluated. GLUT4 protein was analysed in the heart, white adipose tissue and gastrocnemius. Studies were performed at 3 (3-mo, 6 (6-mo and 9 (9-mo months of age. Results MetS rats were more insulin resistant (pvs H, but adiponectin was lower in MetS at 9 months (MetS: 32 ± 2, H: 42 ± 2, C: 45 ± 2 pg/mL; p Conclusions MSG-treated SHR presented all metabolic syndrome characteristics, as well as reduced GLUT4 content, which must play a key role in the impaired glycemic homeostasis of the metabolic syndrome.

  16. Transgenic rice expressing Allium sativum leaf agglutinin (ASAL) exhibits high-level resistance against major sap-sucking pests

    Science.gov (United States)

    Yarasi, Bharathi; Sadumpati, Vijayakumar; Immanni, China Pasalu; Vudem, Dasavantha Reddy; Khareedu, Venkateswara Rao

    2008-01-01

    Background Rice (Oryza sativa) productivity is adversely impacted by numerous biotic and abiotic factors. An approximate 52% of the global production of rice is lost annually owing to the damage caused by biotic factors, of which ~21% is attributed to the attack of insect pests. In this paper we report the isolation, cloning and characterization of Allium sativum leaf agglutinin (asal) gene, and its expression in elite indica rice cultivars using Agrobacterium-mediated genetic transformation method. The stable transgenic lines, expressing ASAL, showed explicit resistance against major sap-sucking pests. Results Allium sativum leaf lectin gene (asal), coding for mannose binding homodimeric protein (ASAL) from garlic plants, has been isolated and introduced into elite indica rice cultivars susceptible to sap-sucking insects, viz., brown planthopper (BPH), green leafhopper (GLH) and whitebacked planthopper (WBPH). Embryogenic calli of rice were co-cultivated with Agrobacterium harbouring pSB111 super-binary vector comprising garlic lectin gene asal along with the herbicide resistance gene bar, both under the control of CaMV35S promoter. PCR and Southern blot analyses confirmed stable integration of transgenes into the genomes of rice plants. Northern and western blot analyses revealed expression of ASAL in different transgenic rice lines. In primary transformants, the level of ASAL protein, as estimated by enzyme-linked immunosorbent assay, varied between 0.74% and 1.45% of the total soluble proteins. In planta insect bioassays on transgenic rice lines revealed potent entomotoxic effects of ASAL on BPH, GLH and WBPH insects, as evidenced by significant decreases in the survival, development and fecundity of the insects. Conclusion In planta insect bioassays were carried out on asal transgenic rice lines employing standard screening techniques followed in conventional breeding for selection of insect resistant plants. The ASAL expressing rice plants, bestowed with high

  17. Transgenic rice expressing Allium sativum leaf agglutinin (ASAL exhibits high-level resistance against major sap-sucking pests

    Directory of Open Access Journals (Sweden)

    Vudem Dasavantha

    2008-10-01

    Full Text Available Abstract Background Rice (Oryza sativa productivity is adversely impacted by numerous biotic and abiotic factors. An approximate 52% of the global production of rice is lost annually owing to the damage caused by biotic factors, of which ~21% is attributed to the attack of insect pests. In this paper we report the isolation, cloning and characterization of Allium sativum leaf agglutinin (asal gene, and its expression in elite indica rice cultivars using Agrobacterium-mediated genetic transformation method. The stable transgenic lines, expressing ASAL, showed explicit resistance against major sap-sucking pests. Results Allium sativum leaf lectin gene (asal, coding for mannose binding homodimeric protein (ASAL from garlic plants, has been isolated and introduced into elite indica rice cultivars susceptible to sap-sucking insects, viz., brown planthopper (BPH, green leafhopper (GLH and whitebacked planthopper (WBPH. Embryogenic calli of rice were co-cultivated with Agrobacterium harbouring pSB111 super-binary vector comprising garlic lectin gene asal along with the herbicide resistance gene bar, both under the control of CaMV35S promoter. PCR and Southern blot analyses confirmed stable integration of transgenes into the genomes of rice plants. Northern and western blot analyses revealed expression of ASAL in different transgenic rice lines. In primary transformants, the level of ASAL protein, as estimated by enzyme-linked immunosorbent assay, varied between 0.74% and 1.45% of the total soluble proteins. In planta insect bioassays on transgenic rice lines revealed potent entomotoxic effects of ASAL on BPH, GLH and WBPH insects, as evidenced by significant decreases in the survival, development and fecundity of the insects. Conclusion In planta insect bioassays were carried out on asal transgenic rice lines employing standard screening techniques followed in conventional breeding for selection of insect resistant plants. The ASAL expressing rice

  18. Transgenic rice expressing Allium sativum leaf agglutinin (ASAL) exhibits high-level resistance against major sap-sucking pests.

    Science.gov (United States)

    Yarasi, Bharathi; Sadumpati, Vijayakumar; Immanni, China Pasalu; Vudem, Dasavantha Reddy; Khareedu, Venkateswara Rao

    2008-10-14

    Rice (Oryza sativa) productivity is adversely impacted by numerous biotic and abiotic factors. An approximate 52% of the global production of rice is lost annually owing to the damage caused by biotic factors, of which approximately 21% is attributed to the attack of insect pests. In this paper we report the isolation, cloning and characterization of Allium sativum leaf agglutinin (asal) gene, and its expression in elite indica rice cultivars using Agrobacterium-mediated genetic transformation method. The stable transgenic lines, expressing ASAL, showed explicit resistance against major sap-sucking pests. Allium sativum leaf lectin gene (asal), coding for mannose binding homodimeric protein (ASAL) from garlic plants, has been isolated and introduced into elite indica rice cultivars susceptible to sap-sucking insects, viz., brown planthopper (BPH), green leafhopper (GLH) and whitebacked planthopper (WBPH). Embryogenic calli of rice were co-cultivated with Agrobacterium harbouring pSB111 super-binary vector comprising garlic lectin gene asal along with the herbicide resistance gene bar, both under the control of CaMV35S promoter. PCR and Southern blot analyses confirmed stable integration of transgenes into the genomes of rice plants. Northern and western blot analyses revealed expression of ASAL in different transgenic rice lines. In primary transformants, the level of ASAL protein, as estimated by enzyme-linked immunosorbent assay, varied between 0.74% and 1.45% of the total soluble proteins. In planta insect bioassays on transgenic rice lines revealed potent entomotoxic effects of ASAL on BPH, GLH and WBPH insects, as evidenced by significant decreases in the survival, development and fecundity of the insects. In planta insect bioassays were carried out on asal transgenic rice lines employing standard screening techniques followed in conventional breeding for selection of insect resistant plants. The ASAL expressing rice plants, bestowed with high entomotoxic

  19. Tellurite glass as a waste form for a simulated mixed chloride waste stream: Candidate materials selection and initial testing

    Energy Technology Data Exchange (ETDEWEB)

    Riley, Brian J.; Rieck, Bennett T.; McCloy, John S.; Crum, Jarrod V.; Sundaram, S. K.; Vienna, John D.

    2012-02-02

    Tellurite glasses have been researched widely for the last 60 years since they were first introduced by Stanworth. These glasses have been primarily used in research applications as glass host materials for lasers and as non-linear optical materials, though many other uses exist in the literature. Tellurite glasses have long since been used as hosts for various, and even sometimes mixed, halogens (i.e., multiple chlorides or even chlorides and iodides). Thus, it was reasonable to expect that these types of glasses could be used as a waste form to immobilize a combination of mixed chlorides present in the electrochemical separations process involved with fuel separations and processing from nuclear reactors. Many of the properties related to waste forms (e.g., chemical durability, maximum chloride loading) for these materials are unknown and thus, in this study, several different types of tellurite glasses were made and their properties studied to determine if such a candidate waste form could be fabricated with these glasses. One of the formulations studied was a lead tellurite glass, which had a low sodium release and is on-par with high-level waste silicate glass waste forms.

  20. Rapid detoxification via glutathione S-transferase (GST) conjugation confers a high level of atrazine resistance in Palmer amaranth (Amaranthus palmeri).

    Science.gov (United States)

    Nakka, Sridevi; Godar, Amar S; Thompson, Curtis R; Peterson, Dallas E; Jugulam, Mithila

    2017-11-01

    Palmer amaranth (Amaranthus palmeri) is an economically troublesome, aggressive and damaging weed that has evolved resistance to six herbicide modes of action including photosystem II (PS II) inhibitors such as atrazine. The objective of this study was to investigate the mechanism and inheritance of atrazine resistance in Palmer amaranth. A population of Palmer amaranth from Kansas (KSR) had a high level (160 - 198-fold more; SE ±21 - 26) of resistance to atrazine compared to the two known susceptible populations MSS and KSS, from Mississippi and Kansas, respectively. Sequence analysis of the chloroplastic psbA gene did not reveal any known mutations conferring resistance to PS II inhibitors, including the most common Ser264Gly substitution for triazine resistance. However, the KSR plants rapidly conjugated atrazine at least 24 times faster than MSS via glutathione S-transferase (GST) activity. Furthermore, genetic analyses of progeny generated from reciprocal crosses of KSR and MSS demonstrate that atrazine resistance in Palmer amaranth is a nuclear trait. Although triazine resistance in Palmer amaranth was reported more than 20 years ago in the USA, this is the first report elucidating the underlying mechanism of resistance to atrazine. The non-target-site based metabolic resistance to atrazine mediated by GST activity may predispose the Palmer amaranth populations to have resistance to other herbicide families, and the nuclear inheritance of the trait in this dioecious species further exacerbates the propensity for its rapid spread. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  1. Enhancing the Electronic Conductivity of Vanadium-tellurite Glasses by Tuning the Redox State

    DEFF Research Database (Denmark)

    Kjeldsen, Jonas; Yue, Yuanzheng

    Transition metal oxides are used in a variety of electronic purposes, e.g., vanadium tellurite as cathode material in high-power demanding batteries. By tuning the redox state of vanadium, it is possible to achieve a lower internal resistance within the entire battery unit, thus a higher capacity....... In this work we vary the redox state of a given vanadium tellurite system by performing post heat-treatment in controlled atmosphere. This process is in theory not limited only to varying electronic conductivity, but also varying the glass structure, and hence, changing properties of the glasses, e.g, thermal...... and mechanical properties. Finally we give insight into the relation between the redox state and electronic conductivity....

  2. Distinct haplotypes of dhfr and dhps among Plasmodium falciparum isolates in an area of high level of sulfadoxine-pyrimethamine (SP) resistance in eastern Sudan.

    Science.gov (United States)

    Al-Saai, Salma; Kheir, Amani; Abdel-Muhsin, Abdel-Muhsin A; Al-Ghazali, Aisha; Nwakanma, Davis; Swedberg, Göte; Babiker, Hamza A

    2009-09-01

    Typing of polymorphic microsatellites that are linked to drug resistance genes has shed light on the origin and pattern of spread of some anti-malarial drugs. Recent surveys revealed spread of a high-level pyrimethemine resistant lineage of Plasmodium falciparum, of Asian origin, across Africa. Here, we examined mutations in dihydrofolate reductase, dhfr [chromsosome 4], the dihydropteroate synthase, dhps [chromosome 8] associated with resistance to sulfadoxine-pyrimethamine (SP), and neighboring microsatellites among P. falciparum isolates in Asar village, eastern Sudan. This area lies at the fringes of malaria endemicity, where the remote P. falciparum parasites have some distinct genetic characteristics. Overall, 89% (84/94) of the examined isolates carried double mutations at dhfr (N51I and S108N), but the 59R and I164L mutations were not seen. Similarly, the majority, 43% (35/81) of the isolates carried double mutations at dhps (437G, 540E). Analysis of neighboring microsatellites revealed one major dhfr haplotype with mutations (51I, 108N) and one dhps haplotype with mutations (436S, 437G, 540E). These haplotypes differ from the major ones thought to drive resistance to SP across Africa. The resistant haplotypes of dhfr and dhps, in Asar, share some microsatellites with the wild genotypes suggesting that they were generated locally. Among isolates successfully examined, 40% shared identical haplotypes of the 2 loci, comprising a dominant resistant lineage. Undoubtedly, this lineage plays an important role in clinical failure to SP in this area.

  3. High-level oxacillin and gentamycin resistance with reduced susceptibility to vancomycin in Staphylococcus aureus-carrying mecA and femA gene complex.

    Science.gov (United States)

    Raju, S; Kelmani Chandrakanth, R; Patil, S A

    2007-06-01

    Staphylococcus aureus oxiva 10 and oxiva 14 strains clinically isolated from diabetic patients were resistant to gentamycin and oxacillin The minimal inhibitory concentrations (MICs) of oxacillin and gentamycin were 720 and >2048 microg/mL, respectively, for oxiva 10 and 680 and 400 microg/mL. respectively, for oxiva 14; both strains carry mecA and femA genetic determinants in their genomes. In addition, both are vancomycin-intermediate Staphylococcus aureus (VISA) isolates. The addition of vancomycin led to significant decreases in oxacillin resistance of both oxiva 10 and oxiva 14 strains, whereas the addition of vancomycin to gentamycin plates showed a decrease in gentamycin resistance of non-high-level gentamycin-resistant (non-HLGR) oxiva 14 and indifference in gentamycin resistance in HLGR oxiva 10. Transmission electron microscopy of representative strains unveils a remarkable increase in the thickness of the cell wall, indicating that thickening of the cell wall is a common phenotype associated with vancomycin resistance in VISA isolates. The present study reports that the rate of synergism and synergistic effect in the combination vancomycin-gentamycin vary according to the MICs of gentamycin.

  4. K70Q adds high-level tenofovir resistance to "Q151M complex" HIV reverse transcriptase through the enhanced discrimination mechanism.

    Directory of Open Access Journals (Sweden)

    Atsuko Hachiya

    2011-01-01

    Full Text Available HIV-1 carrying the "Q151M complex" reverse transcriptase (RT mutations (A62V/V75I/F77L/F116Y/Q151M, or Q151Mc is resistant to many FDA-approved nucleoside RT inhibitors (NRTIs, but has been considered susceptible to tenofovir disoproxil fumarate (TFV-DF or TDF. We have isolated from a TFV-DF-treated HIV patient a Q151Mc-containing clinical isolate with high phenotypic resistance to TFV-DF. Analysis of the genotypic and phenotypic testing over the course of this patient's therapy lead us to hypothesize that TFV-DF resistance emerged upon appearance of the previously unreported K70Q mutation in the Q151Mc background. Virological analysis showed that HIV with only K70Q was not significantly resistant to TFV-DF. However, addition of K70Q to the Q151Mc background significantly enhanced resistance to several approved NRTIs, and also resulted in high-level (10-fold resistance to TFV-DF. Biochemical experiments established that the increased resistance to tenofovir is not the result of enhanced excision, as K70Q/Q151Mc RT exhibited diminished, rather than enhanced ATP-based primer unblocking activity. Pre-steady state kinetic analysis of the recombinant enzymes demonstrated that addition of the K70Q mutation selectively decreases the binding of tenofovir-diphosphate (TFV-DP, resulting in reduced incorporation of TFV into the nascent DNA chain. Molecular dynamics simulations suggest that changes in the hydrogen bonding pattern in the polymerase active site of K70Q/Q151Mc RT may contribute to the observed changes in binding and incorporation of TFV-DP. The novel pattern of TFV-resistance may help adjust therapeutic strategies for NRTI-experienced patients with multi-drug resistant (MDR mutations.

  5. Low-frequency Raman scattering in alkali tellurite glasses

    Indian Academy of Sciences (India)

    Wintec

    TeO3 units with a varying number of non-bridging oxygen atoms. Emphasis has also been given to the low- frequency modes and particular points related to the low-frequency Raman phenomenology are discussed in view of the experimental findings. Keywords. Tellurites; Raman spectroscopy; alkali tellurite glasses. 1.

  6. High-level fluoroquinolone resistant Salmonella enterica serovar Kentucky ST198 epidemic clone with IncA/C conjugative plasmid carrying bla(CTX-M-25) gene.

    Science.gov (United States)

    Wasyl, Dariusz; Kern-Zdanowicz, Izabela; Domańska-Blicharz, Katarzyna; Zając, Magdalena; Hoszowski, Andrzej

    2015-01-30

    Multidrug resistant Salmonella Kentucky strains have been isolated from turkeys in Poland since 2009. Multiple mutations within chromosomal genes gyrA and parC were responsible for high-level ciprofloxacin resistance. One of the isolates was extended spectrum β-lactamase- (ESBL) positive: the strain 1643/2010 carried a conjugative 167,779 bps plasmid of IncA/C family. The sequence analysis revealed that it carried a blaCTX-M-25 gene and an integron with another β-lactamase encoding gene-blaOXA-21. This is the first known report of a CTX-M-25 encoding gene both in Poland and in Salmonella Kentucky world-wide, as well as in the IncA/C plasmid. Analysis of the integron showed a novel arrangement of gene cassettes-aacA4, aacC-A1 and blaOXA-21 where the latter might result from an intergeneric gene transfer. The study confirmed Salmonella Kentucky population isolated in Poland belongs to global epidemics of high level fluoroquinolone resistant clone ST198 that can carry rare β-lactamase genes. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Prevention of peritoneal dialysis catheter infections in Saudi peritoneal dialysis patients: the emergence of high-level mupirocin resistance.

    Science.gov (United States)

    Al-Hwiesh, Abdullah K; Abdul-Rahman, Ibrahiem Saeed; Al-Muhanna, Fahd Abdulaziz; Al-Sulaiman, Mohammed Hamad; Al-Jondebi, Mohammed Shami; Divino-Filho, Jose Carolino

    2013-07-01

    Exit-site infection (ESI) and peritonitis remain the major causes of morbidity and mortality in peritoneal dialysis (PD) patients. This study compared the effectiveness of local mupirocin ointment and gentamicin cream in preventing both gram-positive and gram-negative bacterial infections in PD patients. Patients from two centers (n = 203) were assigned to daily mupirocin ointment or gentamicin cream application. Infections were tracked prospectively by organisms and expressed as episodes per patient-year for both ESI and peritonitis. The rate of gram-positive ESI was 0.31/episode/patient-year and 0.22 episodes/patient-year (pgentamicin group, respectively. Gram-positive ESI occurred in 17.1% vs 10.2% of patients (presistance. Pseudomonas aeruginosa was cultured in 21.8% of ESI in the mupirocin group, and in only 6.7% in the gentamicin group (pgentamicin cream, 0.17 episode/patient-year compared with mupirocin, 0.39 episode/patient-year (pgentamicin exit-site use was a significant predictor for lower catheter infection rate. Prolonged use of mupirocin for ESI-prophylaxis is associated with the emergence of mupirocin-resistant S. aureus. Gentamicin cream is superior to mupirocin ointment in the prevention of PD catheter infections.

  8. Technological advances in tellurite glasses properties, processing, and applications

    CERN Document Server

    Manzani, Danilo

    2017-01-01

    This book is the first to provide a comprehensive introduction to the synthesis, optical properties, and photonics applications of tellurite glasses. The book begins with an overview of tellurite glasses, followed by expert chapters on synthesis, properties, and state-of-the-art applications ranging from laser glass, optical fibers, and optical communications through color tuning, plasmonics, supercontinuum generation, and other photonic devices. The book provides in-depth information on the the structural, linear, and non-linear optical properties of tellurite glasses and their implications for device development. Real-world examples give the reader valuable insight into the applications of tellurite glass. A detailed discussion of glass production methods, including raw materials and melting and refining oxide- and fluoro-tellurite glasses, is also included. The book features an extensive reference list for further reading. This highly readable and didactic text draws on chemical composition, glass science,...

  9. High-level tolerance to triclosan may play a role in Pseudomonas aeruginosa antibiotic resistance in immunocompromised hosts: evidence from outbreak investigation

    Directory of Open Access Journals (Sweden)

    D'Arezzo Silvia

    2012-01-01

    Full Text Available Abstract Background and methods Pseudomonas aeruginosa is a major infectious threat to immunocompromised patients. We recently reported a fatal epidemic of multidrug-resistant P. aeruginosa in an onchoematology unit, linked to massive contamination of a triclosan-based disinfectant. The aim of this study is to evaluate the antimicrobial activity of triclosan and chlorhexidine digluconate against the epidemic strain of P. aeruginosa, to confirm the hypothesis that the soap dispenser acted as a continuous source of the infection during the outbreak, and to explore the potential role of triclosan in increasing the level of resistance to selected antibiotics. Susceptibility tests and time-kill assays for disinfectans were performed using two commercial formulations containing triclosan and chlorhexidine digluconate, respectively. Antibiotic susceptibility testing was performed by the broth microdilution method. Findings The P. aeruginosa epidemic strain exhibited an extremely high level of triclosan resistance (apparent MIC = 2,125 mg/L, while it was markedly susceptible to chlorhexidine digluconate (apparent MIC = 12.5 mg/L. Upon gradual adaptation to triclosan, the epidemic strain survived for a long period (> 120 h in the presence of 3,400 mg/L (equivalent to 1.6 × MIC of triclosan, concomitantly increasing the resistance to six antibiotics that are typical substrates of drug efflux pumps of the resistance nodulation division family. This effect was reversed by efflux pump inhibitors. Conclusions The epidemic P. aeruginosa strain was resistant to triclosan and its previous exposure to triclosan increases antibiotic resistance, likely through active efflux mechanisms. Since P. aeruginosa can become tolerant to elevated triclosan concentrations, the use of triclosan-based disinfectants should be avoided in those healthcare settings hosting patients at high risk for P. aeruginosa infection.

  10. High-level aminoglycoside resistance in Enterococcus faecalis and Enterococcus faecium causing invasive infection: Twelve-year surveillance in the Minami Ibaraki Area.

    Science.gov (United States)

    Osuka, Hanako; Nakajima, Jun; Oishi, Tsuyoshi; Funayama, Yasunori; Ebihara, Tsugio; Ishikawa, Hiroichi; Saito, Kazuto; Koganemaru, Hiroshi; Hitomi, Shigemi

    2016-01-01

    We examined prevalence of high-level aminoglycoside resistance (HLAR) in Enterococcus faecalis and Enterococcus faecium causing invasive infection in the Minami Ibaraki Area. Ten strains of both species each, recovered from the blood or the cerebrospinal fluid between 2003 and 2014, were randomly selected every year. High-level resistance to gentamicin (HLR-GM) and streptomycin (HLR-SM) was detected in 34% (41 of 120 strains) and 18% (21) of E. faecalis and 9% (11) and 39% (48) of E. faecium, respectively. In comparisons of the proportions among three four-year periods, HLR-SM among E. faecium was significantly lower in the 2011-2014 period. All strains with HLR-GM were positive for the aac(6')-Ie-aph(2″)-Ia gene. The ant(6')-Ia gene was detected in all with HLR-SM except for one E. faecalis strain. The present study showed that prevalence of HLR-GM among E. faecalis and E. faecium causing invasive infection in this area was nearly equivalent to that described in previous studies in Japan and that proportions of strains with HLAR did not vary during the study period except for that of HLR-SM among E. faecium. Copyright © 2015 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  11. Optical properties of bismuth tellurite based glass.

    Science.gov (United States)

    Oo, Hooi Ming; Mohamed-Kamari, Halimah; Wan-Yusoff, Wan Mohd Daud

    2012-01-01

    A series of binary tellurite based glasses (Bi(2)O(3))(x) (TeO(2))(100-) (x) was prepared by melt quenching method. The density, molar volume and refractive index increase when bismuth ions Bi(3+) increase, this is due to the increased polarization of the ions Bi(3+) and the enhanced formation of non-bridging oxygen (NBO). The Fourier transform infrared spectroscopy (FTIR) results show the bonding of the glass sample and the optical band gap, E(opt) decreases while the refractive index increases when the ion Bi(3+) content increases.

  12. Optical Properties of Bismuth Tellurite Based Glass

    Directory of Open Access Journals (Sweden)

    Hooi Ming Oo

    2012-04-01

    Full Text Available A series of binary tellurite based glasses (Bi2O3x (TeO2100−x was prepared by melt quenching method. The density, molar volume and refractive index increase when bismuth ions Bi3+ increase, this is due to the increased polarization of the ions Bi3+ and the enhanced formation of non-bridging oxygen (NBO. The Fourier transform infrared spectroscopy (FTIR results show the bonding of the glass sample and the optical band gap, Eopt decreases while the refractive index increases when the ion Bi3+ content increases.

  13. Optical Properties of Bismuth Tellurite Based Glass

    Science.gov (United States)

    Oo, Hooi Ming; Mohamed-Kamari, Halimah; Wan-Yusoff, Wan Mohd Daud

    2012-01-01

    A series of binary tellurite based glasses (Bi2O3)x (TeO2)100−x was prepared by melt quenching method. The density, molar volume and refractive index increase when bismuth ions Bi3+ increase, this is due to the increased polarization of the ions Bi3+ and the enhanced formation of non-bridging oxygen (NBO). The Fourier transform infrared spectroscopy (FTIR) results show the bonding of the glass sample and the optical band gap, Eopt decreases while the refractive index increases when the ion Bi3+ content increases. PMID:22605999

  14. Genetic relatedness and risk factor analysis of ampicillin-resistant and high-level gentamicin-resistant enterococci causing bloodstream infections in Tanzanian children

    NARCIS (Netherlands)

    Aamodt, Håvard; Mohn, Stein Christian; Maselle, Samuel; Manji, Karim P; Willems, Rob; Jureen, Roland; Langeland, Nina; Blomberg, Bjørn

    2015-01-01

    BACKGROUND: While enterococci resistant to multiple antimicrobials are spreading in hospitals worldwide, causing urinary tract, wound and bloodstream infections, there is little published data on these infections from Africa. METHODS: We assessed the prevalence, susceptibility patterns, clinical

  15. Comparative study of enzymatic activities of new KatG mutants from low- and high-level isoniazid-resistant clinical isolates of Mycobacterium tuberculosis.

    Science.gov (United States)

    Brossier, Florence; Boudinet, Marlène; Jarlier, Vincent; Petrella, Stéphanie; Sougakoff, Wladimir

    2016-09-01

    Resistance to isoniazid (INH-R) in Mycobacterium tuberculosis is mainly due to mutations at position 315 (S315T) of the catalase-peroxidase KatG. We identified 16 mutations (including 13 biochemically uncharacterized mutations) in KatG from INH-R clinical isolates of M. tuberculosis showing mutations other than S315T. The KatG enzymatic activities (catalase, peroxidase, free radical production and isonicotinoyl-NAD formation) of wild-type KatG and the 16 mutants were determined and correlated to their spatial location in a KatG model structure. Of all mutations studied, H270R, which conferred a high level of INH-R and results in the disruption of a coordination bond with the heme, caused complete loss of all enzymatic KatG activities. The mutants generally associated with a very high level of INH-R were all characterized by a drastic reduction in catalase activity and a marked decrease in INH activation activities. One mutant, A162E, displayed a behavior similar to S315T, i.e. a moderate decrease in catalase activity and a drastic decrease in the formation of the radical form of INH. Finally, the mutants associated with a low level of INH-R showed a moderate reduction in the four catalytic activities, likely stemming from an overall alteration of the folding and/or stability of the KatG protein. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Flavoprotein-mediated tellurite reduction: structural basis and applications to the synthesis of tellurium-containing nanostructures

    Directory of Open Access Journals (Sweden)

    Mauricio Arenas-Salinas

    2016-07-01

    Full Text Available The tellurium oxyanion tellurite (TeO32- is extremely harmful for most organisms. It has been suggested that a potential bacterial tellurite resistance mechanism would consist of an enzymatic, NAD(PH-dependent, reduction to the less toxic form elemental tellurium (Te0. To date, a number of enzymes such as catalase, type II NADH dehydrogenase and terminal oxidases from the electron transport chain, nitrate reductases, and dihydrolipoamide dehydrogenase (E3, among others, have been shown to display tellurite-reducing activity. This activity is generically referred to as tellurite reductase (TR. Bioinformatic data resting on some of the abovementioned enzymes enabled the identification of common structures involved in tellurite reduction including vicinal catalytic cysteine residues and the FAD/NAD(P+-binding domain, which is characteristic of some flavoproteins. Along this line, thioredoxin reductase (TrxB, alkyl hydroperoxide reductase (AhpF, glutathione reductase (GorA, mercuric reductase (MerA, NADH: flavorubredoxin reductase (NorW, dihydrolipoamide dehydrogenase, and the putative oxidoreductase YkgC from Escherichia coli or environmental bacteria were purified and assessed for TR activity. All of them displayed in vitro TR activity at the expense of NADH or NADPH oxidation. In general, optimal reducing conditions occurred around pH 9-10 and 37 °C.Enzymes exhibiting strong TR activity produced Te-containing nanostructures (TeNS. While GorA and AhpF generated TeNS of 75 nm average diameter, E3 and YkgC produced larger structures (> 100 nm. Electron-dense structures were observed in cells over-expressing genes encoding TrxB, GorA and YkgC.

  17. Genetic diversity of enterococci harboring the high-level gentamicin resistance gene aac(6')-Ie-aph(2'')-Ia or aph(2'')-Ie in a Japanese hospital.

    Science.gov (United States)

    Watanabe, Shojiro; Kobayashi, Nobumichi; Quiñones, Dianelys; Nagashima, Shigeo; Uehara, Nobuyuki; Watanabe, Naoki

    2009-09-01

    Prevalence of high-level gentamicin resistance genes aac(6')-Ie-aph(2'')-Ia and aph(2'')-Ie, which encode distinct aminoglycoside-modifying enzymes, was analyzed for a total of 1128 clinical isolates of enterococci obtained in a Japanese hospital during a period between 1997 and 2007. The aac(6')-Ie-aph(2'')-Ia was detected in 40.1%, 12.9%, and 3.6% of Enterococcus faecalis, E. faecium, and other enterococcal species, respectively, and aph(2'')-Ie was detected in 3.3% of E. faecium. During the study period, detection rate of aac(6')-Ie-aph(2'')-Ia in E. faecium increased from 4% (1997-1998) to 28% (2006-2007), whereas generally constant in E. faecalis. By the analysis of IS256-flanking patterns of aac(6')-Ie-aph(2'')-Ia, truncated forms of Tn5281 lacking IS256 at the 3'-end, 5'-end, and both ends of aac(6')-Ie-aph(2'')-Ia were identified in 4.6%, 32.4%, and 34.2% of E. faecalis strains, respectively, while the composite Tn5281-like element with IS256 at both sides was detected in 28.7% of the strains. A truncated form of Tn5281 lacking IS256 at the 5'-end was predominant in other enterococcal species. Among 14 E. faecalis and 10 E. faecium strains harboring aac(6')-Ie-aph(2'')-Ia, 8 and 6 different sequence types (STs) were identified by multilocus sequence typing, respectively. Some E. faecalis STs (ST4, ST16, ST64, and ST223) were found in more than one strain, and ST4 and ST64 were associated with different IS256-flanking patterns. STs of five among six E. faecium strains with aac(6')-Ie-aph(2'')-Ia (ST78, ST203, and ST418) belonged to the clonal complex (CC)17, which is known as globally emerging lineage of vancomycin- or ampicillin-resistant E. faecium clones. E. faecium strains with aph(2'')-Ie were classified into newly assigned STs, ST426, and its single locus variant ST427, which also belonged to CC17. Therefore, it was suggested that E. faecium of CC17 is prone to acquire high-level gentamicin resistance genes, and aph(2'')-Ie is distributed to specific E

  18. Comparative study of bacteremias caused by Enterococcus spp. with and without high-level resistance to gentamicin. The Grupo Andaluz para el estudio de las Enfermedades Infecciosas.

    Science.gov (United States)

    Caballero-Granado, F J; Cisneros, J M; Luque, R; Torres-Tortosa, M; Gamboa, F; Díez, F; Villanueva, J L; Pérez-Cano, R; Pasquau, J; Merino, D; Menchero, A; Mora, D; López-Ruz, M A; Vergara, A

    1998-02-01

    A prospective, multicenter study was carried out over a period of 10 months. All patients with clinically significant bacteremia caused by Enterococcus spp. were included. The epidemiological, microbiological, clinical, and prognostic features and the relationship of these features to the presence of high-level resistance to gentamicin (HLRG) were studied. Ninety-three patients with enterococcal bacteremia were included, and 31 of these cases were caused by HLRG (33%). The multivariate analysis selected chronic renal failure, intensive care unit stay, previous use of antimicrobial agents, and Enterococcus faecalis species as the independent risk factors that influenced the development of HLRG. The strains with HLRG showed lower levels of susceptibility to penicillin and ciprofloxacin. Clinical features (except for chronic renal failure) were similar in both groups of patients. HLRG did not influence the prognosis for patients with enterococcal bacteremia in terms of either the crude mortality rate (29% for patients with bacteremia caused by enterococci with HLRG and 28% for patients not infected with strains with HLRG) or the hospital stay after the acquisition of enterococcal bacteremia. Hemodynamic compromise, inappropriate antimicrobial therapy, and mechanical ventilation were revealed in the multivariate analysis to be the independent risk factors for mortality. Prolonged hospitalization was associated with the nosocomial acquisition of bacteremia and polymicrobial infections.

  19. Low-threshold stimulated Brillouin scattering in high-Q whispering gallery mode tellurite microspheres.

    Science.gov (United States)

    Guo, Changlei; Che, Kaijun; Zhang, Pan; Wu, Jinshu; Huang, Yantang; Xu, Huiying; Cai, Zhiping

    2015-12-14

    We demonstrate the first observation of stimulated Brillouin scattering (SBS) in a high-Q whispering gallery mode tellurite microsphere. Tellurite glass with composition of 70TeO₂-20ZnO-5Na₂O-5La₂O₃ (molar ratio) was prepared in-house using a melt-quenching technique. Moreover, tellurite microspheres with Q in excess of 13 millions at 1550 nm were fabricated by melting tellurite microwires using a CO₂ laser. By pumping the tellurite microspheres with a tunable single frequency laser, SBS is further realized with a threshold as low as 0.58 mW. At last, the beat notes between the pump and the Stokes signals were measured, which indicated the Brillouin frequency shift is at the 8.2 GHz band for our tellurite glass. Our results could propel significant applications utilizing SBS by employing tellurite microspheres.

  20. Tellurite glasses for vitrification of technetium-99 from pyrochemical processing

    Science.gov (United States)

    Pyo, Jae-Young; Lee, Cheong Won; Park, Hwan-Seo; Yang, Jae Hwan; Um, Wooyong; Heo, Jong

    2017-09-01

    A new alkali-alumino tellurite glass composition was developed to immobilize highly-volatile technetium (Tc) wastes generated from the pyrochemical processing technology. Tellurite glass can incorporate up to 7 mass% of rhenium (Re, used as a surrogate for Tc) with an average retention of 86%. Normalized elemental releases evaluated by seven-day product consistency test (PCT) satisfied the immobilized low activity waste requirements of United States when concentration of Ca(ReO4)2 in the glass was <12 mass%. Re ions form Re7+ and are coordinated with four oxygens to form ReO4- tetrahedra. These tetrahedra bond to modifiers such as Ca2+ or Na+ that are further connected to the tellurite glass network by Ca2+ (or Na+) - non-bridging oxygen bonds.

  1. High-level verification

    CERN Document Server

    Lerner, Sorin; Kundu, Sudipta

    2011-01-01

    Given the growing size and heterogeneity of Systems on Chip (SOC), the design process from initial specification to chip fabrication has become increasingly complex. This growing complexity provides incentive for designers to use high-level languages such as C, SystemC, and SystemVerilog for system-level design. While a major goal of these high-level languages is to enable verification at a higher level of abstraction, allowing early exploration of system-level designs, the focus so far for validation purposes has been on traditional testing techniques such as random testing and scenario-based

  2. Draft Genome Sequences of Two Streptococcus pneumoniae Serotype 19A Sequence Type 226 Clinical Isolates from Hungary, Hu17 with High-Level Beta-Lactam Resistance and Hu15 of a Penicillin-Sensitive Phenotype.

    Science.gov (United States)

    Rieger, Martin; Denapaite, Dalia; Brückner, Reinhold; Maurer, Patrick; Hakenbeck, Regine

    2017-05-18

    The draft genome sequences of two multiple-antibiotic-resistant Streptococcus pneumoniae isolates from Hungary, Hu15 and Hu17, are reported here. Strain Hu15 is penicillin susceptible, whereas Hu17 is a high-level-penicillin-resistant strain. Both isolates belong to the serotype 19A sequence type 226, a single-locus variant (in the ddl locus) of the Hungary(19A)-6 clone. Copyright © 2017 Rieger et al.

  3. High Levels of Dual-Class Drug Resistance in HIV-Infected Children Failing First-Line Antiretroviral Therapy in Southern Ethiopia.

    Science.gov (United States)

    Tadesse, Birkneh Tilahun; Kinloch, Natalie N; Baraki, Bemuluyigza; Lapointe, Hope R; Cobarrubias, Kyle D; Brockman, Mark A; Brumme, Chanson J; Foster, Byron A; Jerene, Degu; Makonnen, Eyasu; Aklillu, Eleni; Brumme, Zabrina L

    2018-02-01

    Clinical monitoring of pediatric HIV treatment remains a major challenge in settings where drug resistance genotyping is not routinely available. As a result, our understanding of drug resistance, and its impact on subsequent therapeutic regimens available in these settings, remains limited. We investigate the prevalence and correlates of HIV-1 drug resistance among 94 participants of the Ethiopia Pediatric HIV Cohort failing first-line combination antiretroviral therapy (cART) using dried blood spot-based genotyping. Overall, 81% (73/90) of successfully genotyped participants harbored resistance mutations, including 69% (62/90) who harbored resistance to both Nucleoside Reverse Transcriptase Inhibitors (NRTIs) and Non-nucleoside Reverse Transcriptase Inhibitors (NNRTIs). Strikingly, 42% of resistant participants harbored resistance to all four NRTIs recommended for second-line use in this setting, meaning that there are effectively no remaining cART options for these children. Longer cART duration and prior regimen changes were significantly associated with detection of drug resistance mutations. Replicate genotyping increased the breadth of drug resistance detected in 34% of cases, and thus is recommended for consideration when typing from blood spots. Implementation of timely drug resistance testing and access to newer antiretrovirals and drug classes are urgently needed to guide clinical decision-making and improve outcomes for HIV-infected children on first-line cART in Ethiopia.

  4. Li ion conductivities in boro-tellurite glasses

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Lithium ion conductivity has been investigated in a boro-tellurite glass system, LiCl⋅LiBO2⋅TeO2. In the absence of LiCl, the conductivity increases with increasing non-bridging oxygen (NBO) concentration. LiCl addition has little influence on total conductivity although the observed barriers are low. Formation of.

  5. Optical properties of samarium doped zinc–tellurite glasses

    Indian Academy of Sciences (India)

    Unknown

    Optical properties of samarium doped zinc–tellurite glasses. B ERAIAH. Department of Physics, Karnatak University, Dharwad 580 003, India. Present address: Department of Physics, Bangalore University, Bangalore 560 056, India. MS received 20 March 2006; revised 13 June 2006. Abstract. Glasses with the composition, ...

  6. Fragility–structure–conductivity relations in vanadium tellurite glass

    DEFF Research Database (Denmark)

    Kjeldsen, Jonas; Yue, Yuanzheng; Rodrigues, Ana Candida Martins

    the ability to intercalate lithium-ions, it is a candidate as cathode material. Here, we investigate the correlation between liquid fragility, structure and electronic conductivity in a series of vanadium-tellurite glasses with varying vanadium concentration. We measure dynamic and thermodynamic fragility...

  7. Acoustic relaxation of some lead niobium tellurite glasses

    Indian Academy of Sciences (India)

    5−(0.9−)TeO2 and 0.2PbO − Nb2O5− (0.8−)TeO2 tellurite glass systems was measured using the pulse echo technique at ultrasonic frequencies 2, 4, 6 and 8 MHz in the temperature range from 150 to 300 K. The absorption curves ...

  8. ALICE High Level Trigger

    CERN Multimedia

    Alt, T

    2013-01-01

    The ALICE High Level Trigger (HLT) is a computing farm designed and build for the real-time, online processing of the raw data produced by the ALICE detectors. Events are fully reconstructed from the raw data, analyzed and compressed. The analysis summary together with the compressed data and a trigger decision is sent to the DAQ. In addition the reconstruction of the events allows for on-line monitoring of physical observables and this information is provided to the Data Quality Monitor (DQM). The HLT can process event rates of up to 2 kHz for proton-proton and 200 Hz for Pb-Pb central collisions.

  9. Is Neisseria gonorrhoeae Initiating a Future Era of Untreatable Gonorrhea?: Detailed Characterization of the First Strain with High-Level Resistance to Ceftriaxone ▿ †

    Science.gov (United States)

    Ohnishi, Makoto; Golparian, Daniel; Shimuta, Ken; Saika, Takeshi; Hoshina, Shinji; Iwasaku, Kazuhiro; Nakayama, Shu-ichi; Kitawaki, Jo; Unemo, Magnus

    2011-01-01

    Recently, the first Neisseria gonorrhoeae strain (H041) that is highly resistant to the extended-spectrum cephalosporin (ESC) ceftriaxone, the last remaining option for empirical first-line treatment, was isolated. We performed a detailed characterization of H041, phenotypically and genetically, to confirm the finding, examine its antimicrobial resistance (AMR), and elucidate the resistance mechanisms. H041 was examined using seven species-confirmatory tests, antibiograms (30 antimicrobials), porB sequencing, N. gonorrhoeae multiantigen sequence typing (NG-MAST), multilocus sequence typing (MLST), and sequencing of ESC resistance determinants (penA, mtrR, penB, ponA, and pilQ). Transformation, using appropriate recipient strains, was performed to confirm the ESC resistance determinants. H041 was assigned to serovar Bpyust, MLST sequence type (ST) ST7363, and the new NG-MAST ST4220. H041 proved highly resistant to ceftriaxone (2 to 4 μg/ml, which is 4- to 8-fold higher than any previously described isolate) and all other cephalosporins, as well as most other antimicrobials tested. A new penA mosaic allele caused the ceftriaxone resistance. In conclusion, N. gonorrhoeae has now shown its ability to also develop ceftriaxone resistance. Although the biological fitness of ceftriaxone resistance in N. gonorrhoeae remains unknown, N. gonorrhoeae may soon become a true superbug, causing untreatable gonorrhea. A reduction in the global gonorrhea burden by enhanced disease control activities, combined with wider strategies for general AMR control and enhanced understanding of the mechanisms of emergence and spread of AMR, which need to be monitored globally, and public health response plans for global (and national) perspectives are important. Ultimately, the development of new drugs for efficacious gonorrhea treatment is necessary. PMID:21576437

  10. Transgenic banana plants expressing small interfering RNAs targeted against viral replication initiation gene display high-level resistance to banana bunchy top virus infection.

    Science.gov (United States)

    Shekhawat, Upendra K S; Ganapathi, Thumballi R; Hadapad, Ashok B

    2012-08-01

    The banana aphid-transmitted Banana bunchy top virus (BBTV) is the most destructive viral pathogen of bananas and plantains worldwide. Lack of natural sources of resistance to BBTV has necessitated the exploitation of proven transgenic technologies for obtaining BBTV-resistant banana cultivars. In this study, we have explored the concept of using intron-hairpin-RNA (ihpRNA) transcripts corresponding to viral master replication initiation protein (Rep) to generate BBTV-resistant transgenic banana plants. Two ihpRNA constructs namely ihpRNA-Rep and ihpRNA-ProRep generated using Rep full coding sequence or Rep partial coding sequence together with its 5' upstream regulatory region, respectively, and castor bean catalase intron were successfully transformed into banana embryogenic cells. ihpRNA-Rep- and ihpRNA-ProRep-derived transgenic banana plants, selected based on preliminary screening for efficient reporter gene expression, were completely resistant to BBTV infection as indicated by the absence of disease symptoms after 6 months of viruliferous aphid inoculation. The resistance to BBTV infection was also evident by the inability to detect cDNAs coding for viral coat protein, movement protein and Rep protein by RT-PCR from inoculated transgenic leaf extracts. Southern analysis of the two groups of transgenics showed that ihpRNA transgene was stably integrated into the banana genome. The detection of small interfering RNAs (siRNAs) derived from the ihpRNA transgene sequence in transformed BBTV-resistant plants positively established RNA interference as the mechanism underlying the observed resistance to BBTV. Efficient screening of optimal transformants in this vegetatively propagated non-segregating fruit crop ensured that all the transgenic plants assayed were resistant to BBTV infection.

  11. Effectiveness and cost-effectiveness of potential responses to future high levels of transmitted HIV drug resistance in antiretroviral drug-naive populations beginning treatment

    DEFF Research Database (Denmark)

    Phillips, Andrew N; Cambiano, Valentina; Miners, Alec

    2014-01-01

    BACKGROUND: With continued roll-out of antiretroviral therapy (ART) in resource-limited settings, evidence is emerging of increasing levels of transmitted drug-resistant HIV. We aimed to compare the effectiveness and cost-effectiveness of different potential public health responses to substantial......-effectiveness threshold. Results from our model will help inform WHO recommendations on monitoring of HIV drug resistance in people starting ART. FUNDING: WHO (with funds provided by the Bill & Melinda Gates Foundation), CHAIN (European Commission)....

  12. Important Mutations Contributing to High-Level Penicillin Resistance in Taiwan19F-14, Taiwan23F-15, and Spain23F-1 of Streptococcus pneumoniae Isolated from Taiwan.

    Science.gov (United States)

    Liu, Esther Yip-Mei; Chang, Jen-Chang; Lin, Jung-Chung; Chang, Feng-Yee; Fung, Chang-Phone

    2016-12-01

    Penicillin-resistant Streptococcus pneumoniae is a serious concern worldwide. In this study, we analyzed the cause of β-lactam resistance in pandemic multidrug-resistant clones. A total of 41 penicillin-nonsusceptible clinical isolates were collected from 1996 to 2012. Sero- and molecular typing confirmed that these isolates were clonal types of Taiwan19F-14, Taiwan23F-15, and Spain23F-1. Sero-switching was found in four isolates. All isolates were multidrug resistant. Sequencing analysis of the penicillin binding proteins (PBPs) was performed on PBP1a, 2b, and 2x, and a large number of mutations were identified in comparing to clinical penicillin-susceptible isolates and the recipient strain R6 used for homologous recombination. The T451A substitution was the key amino acid in PBP2b that contributed to penicillin resistance. T338A in PBP2x played a role in resistance and reached the highest level of resistance when combined with other mutations in PBP2x. High-level penicillin resistance could not be obtained without the combination of mutations in PBP1a with PBP2b and 2x. The amino acid substitutions in PBP1a, 2b, and 2x were the crucial factors for β-lactam resistance.

  13. Detection of high levels of mutations involved in anti-malarial drug resistance in Plasmodium falciparum and Plasmodium vivax at a rural hospital in southern Ethiopia

    Directory of Open Access Journals (Sweden)

    González Vicenta

    2011-08-01

    Full Text Available Abstract Background In Ethiopia, malaria is caused by Plasmodium falciparum and Plasmodium vivax, and anti-malarial drug resistance is the most pressing problem confronting control of the disease. Since co-infection by both species of parasite is common and sulphadoxine-pyrimethamine (SP has been intensively used, resistance to these drugs has appeared in both P. falciparum and P. vivax populations. This study was conducted to assess the prevalence of anti-malarial drug resistance in P. falciparum and P. vivax isolates collected at a rural hospital in southern Ethiopia. Methods A total of 1,147 patients with suspected malaria were studied in different months across the period 2007-2009. Plasmodium falciparum dhfr and dhps mutations and P. vivax dhfr polymorphisms associated with resistance to SP, as well as P. falciparum pfcrt and pfmdr1 mutations conferring chloroquine resistance, were assessed. Results PCR-based diagnosis showed that 125 of the 1147 patients had malaria. Of these, 52.8% and 37.6% of cases were due to P. falciparum and P. vivax respectively. A total of 10 cases (8% showed co-infection by both species and two cases (1.6% were infected by Plasmodium ovale. Pfdhfr triple mutation and pfdhfr/pfdhps quintuple mutation occurred in 90.8% (95% confidence interval [CI]: 82.2%-95.5% and 82.9% (95% CI: 72.9%-89.7% of P. falciparum isolates, respectively. Pfcrt T76 was observed in all cases and pfmdr1 Y86 and pfmdr1 Y1246 in 32.9% (95% CI: 23.4%-44.15% and 17.1% (95% CI: 10.3-27.1%, respectively. The P. vivax dhfr core mutations, N117 and R58, were present in 98.2% (95% CI: 89.4-99.9% and 91.2% (95% CI: 80.0-96.7%, respectively. Conclusion Current molecular data show an extraordinarily high frequency of drug-resistance mutations in both P. falciparum and P. vivax in southern Ethiopia. Urgent surveillance of the emergence and spread of resistance is thus called for. The level of resistance indicates the need for implementation of entire

  14. Tellurite glass as a waste form for mixed alkali-chloride waste streams: Candidate materials selection and initial testing

    Energy Technology Data Exchange (ETDEWEB)

    Riley, Brian J., E-mail: brian.riley@pnnl.gov [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Rieck, Bennett T. [Washington State University, Pullman, WA 99164 (United States); McCloy, John S.; Crum, Jarrod V. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Sundaram, S.K. [Alfred University, Alfred, NY 14802 (United States); Vienna, John D. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States)

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer We provide the first standardized chemical durability test on tellurite glasses. Black-Right-Pointing-Pointer The glasses we studied showed a wide variety of chemical durability. Black-Right-Pointing-Pointer The best-performing glass showed good halide retention following melting and durability testing. Black-Right-Pointing-Pointer These glasses have very high densities resulting in high volumetric waste loading ability. - Abstract: Tellurite glasses have historically been shown to host large concentrations of halides. They are here considered for the first time as a waste form for immobilizing chloride wastes, such as may be generated in the proposed molten alkali salt electrochemical separations step in nuclear fuel reprocessing. Key properties of several tellurite glasses are determined to assess acceptability as a chloride waste form. TeO{sub 2} glasses with other oxides (PbO, Al{sub 2}O{sub 3} + B{sub 2}O{sub 3}, WO{sub 3}, P{sub 2}O{sub 5}, or ZnO) were fabricated with and without 10 mass% of a simulated (non-radioactive) mixed alkali, alkaline-earth, and rare earth chloride waste. Measured chemical durability is compared for the glasses, as determined by the product consistency test (PCT), a common standardized chemical durability test often used to validate borosilicate glass waste forms. The glass with the most promise as a waste form is the TeO{sub 2}-PbO system, as it offers good halide retention, a low sodium release (by PCT) comparable with high-level waste silicate glass waste forms, and a high storage density.

  15. Combinations of mutations in envZ, ftsI, mrdA, acrB and acrR can cause high-level carbapenem resistance in Escherichia coli

    DEFF Research Database (Denmark)

    Adler, Marlen; Anjum, Mehreen; Andersson, Dan I.

    2016-01-01

    of meropenem or ertapenem for similar to 60 generations. Isolated clones were whole-genome sequenced, and the order in which the identified mutations arose was determined in the passaged populations. Key mutations were reconstructed, and bacterial growth rates of populations and isolated clones and resistance...... levels to 23 antibiotics were measured. High-level resistance to carbapenems resulted from a combination of downstream effects of envZ mutation and target mutations in AcrAB-TolC-mediated drug export, together with PBP genes [mrdA (PBP2) after meropenem exposure or ftsI (PBP3) after ertapenem exposure...

  16. Successful low-dose leflunomide treatment for ganciclovir-resistant cytomegalovirus infection with high-level antigenemia in a kidney transplant: A case report and literature review.

    Science.gov (United States)

    Morita, Shinya; Shinoda, Kazunobu; Tamaki, Satoshi; Kono, Hidaka; Asanuma, Hiroshi; Nakagawa, Ken; Oya, Mototsugu

    2016-09-01

    Ganciclovir-resistant cytomegalovirus infection is sometimes life-threatening for organ transplant recipients. Foscarnet is an alternative, although it may potentially worsen the preexistent impaired renal function. Here we report the case of a successful low-dose leflunomide treatment in a kidney transplant recipient with very high viral replication, who underwent kidney transplantation 10 years before. Administering 10mg leflunomide daily for 5 months without a loading dose completely cleared the ganciclovir-resistant cytomegalovirus strains. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. A Novel Mechanism of High-Level, Broad-Spectrum Antibiotic Resistance Caused by a Single Base Pair Change in Neisseria gonorrhoeae

    Science.gov (United States)

    2011-09-20

    transcriptase ( Invitro - gen Co., Carlsbad, CA) according to the manufacturer’s instructions. Enhanced Antibiotic Resistance by a Novel Promoter Mutation...mutate the 10 region of the wild-type mtrC promoter from TATAAT to TGTCAC. PCR products were digested with BamHI, and the resulting DNA frag- ments

  18. High levels of multidrug resistant tuberculosis in new and treatment-failure patients from the Revised National Tuberculosis Control Programme in an urban metropolis (Mumbai in Western India

    Directory of Open Access Journals (Sweden)

    Nicol Mark

    2009-06-01

    Full Text Available Abstract Background India, China and Russia account for more than 62% of multidrug resistant tuberculosis (MDRTB globally. Within India, locations like urban metropolitan Mumbai with its burgeoning population and high incidence of TB are suspected to be a focus for MDRTB. However apart from sporadic surveys at watched sites in the country, there has been no systematic attempt by the Revised National Tuberculosis Control Programme (RNTCP of India to determine the extent of MDRTB in Mumbai that could feed into national estimates. Drug susceptibility testing (DST is not routinely performed as a part of programme policy and public health laboratory infrastructure, is limited and poorly equipped to cope with large scale testing. Methods From April 2004 to January 2007 we determined the extent of drug resistance in 724 {493 newly diagnosed, previously untreated and 231 first line treatment failures (sputum-smear positive at the fifth month after commencement of therapy} cases of pulmonary tuberculosis drawn from the RNTCP in four suboptimally performing municipal wards of Mumbai. The observations were obtained using a modified radiorespirometric Buddemeyer assay and validated by the Swedish Institute for Infectious Disease Control, Stockholm, a supranational reference laboratory. Data was analyzed utilizing SPSS 10.0 and Epi Info 2002. Results This study undertaken for the first time in RNTCP outpatients in Mumbai reveals a high proportion of MDRTB strains in both previously untreated (24% and treatment-failure cases (41%. Amongst new cases, resistance to 3 or 4 drug combinations (amplified drug resistance including isoniazid (H and rifampicin (R, was greater (20% than resistance to H and R alone (4% at any point in time during the study. The trend for monoresistance was similar in both groups remaining highest to H and lowest to R. External quality control revealed good agreement for H and R resistance (k = 0.77 and 0.76 respectively. Conclusion

  19. High Levels of Antibiotic Resistance Genes and Their Correlations with Bacterial Community and Mobile Genetic Elements in Pharmaceutical Wastewater Treatment Bioreactors

    OpenAIRE

    Tao, Wenda; Zhang, Xu-Xiang; Zhao, Fuzheng; Huang, Kailong; Ma, Haijun; Wang, Zhu; Ye, Lin; Ren, Hongqiang

    2016-01-01

    To understand the diversity and abundance of antibiotic resistance genes (ARGs) in pharmaceutical wastewater treatment bioreactors, the ARGs in sludge from two full-scale pharmaceutical wastewater treatment plants (PWWTPs) were investigated and compared with sludge samples from three sewage treatment plants (STPs) using metagenomic approach. The results showed that the ARG abundances in PWWTP sludge ranged from 54.7 to 585.0 ppm, which were higher than those in STP sludge (27.2 to 86.4 ppm). ...

  20. Outbreak of Serratia marcescens Coproducing ArmA and CTX-M-15 Mediated High Levels of Resistance to Aminoglycoside and Extended-Spectrum Beta-Lactamases, Algeria.

    Science.gov (United States)

    Batah, Rima; Loucif, Lotfi; Olaitan, Abiola Olumuyiwa; Boutefnouchet, Nafissa; Allag, Hamoudi; Rolain, Jean-Marc

    2015-08-01

    Serratia marcescens is one of the most important pathogens responsible for nosocomial infections worldwide. Here, we have investigated the molecular support of antibiotic resistance and genetic relationships in a series of 54 S. marcescens clinical isolates collected from Eastern Algeria between December 2011 and July 2013. The 54 isolates were identified by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). Antibiotic susceptibility testing was performed by disc diffusion and E-test methods. Antibiotic resistance genes were detected by polymerase chain reaction (PCR). The genetic transfer of antibiotic resistance was performed by conjugation using azide-resistant Escherichia coli J53 as the recipient strain, and plasmid analysis was done by PCR-based replicon typing. The relatedness of our isolates was determined by phylogenetic analysis based on partial sequences of four protein-encoding genes (gyrB, rpoB, infB, and atpD) and then compared to MALDI-TOF MS clustering. Thirty-five out of 54 isolates yielded an extended-spectrum β-lactamase (ESBL) phenotype and carried bla(CTX-M-15) (n=32), bla(TEM-1) (n=26), bla(TEM-71) (n=1), bla(SHV-1a) (n=1), and bla(PER-2) (n=12). Among these isolates, we identified a cluster of 15 isolates from a urology unit that coharbored ESBL and the 16S rRNA methyltransferase armA. Conjugation was successful for five selected strains, demonstrating the transferability of a conjugative plasmid of incompatibility group incL/M type. Phylogenetic analysis along with MALDI-TOF clustering likely suggested an outbreak of such isolates in the urology unit. In this study, we report for the first time the co-occurrence of armA methyltransferase with ESBL in S. marcescens clinical isolates in Eastern Algeria.

  1. High Levels of Antibiotic Resistance Genes and Their Correlations with Bacterial Community and Mobile Genetic Elements in Pharmaceutical Wastewater Treatment Bioreactors.

    Science.gov (United States)

    Tao, Wenda; Zhang, Xu-Xiang; Zhao, Fuzheng; Huang, Kailong; Ma, Haijun; Wang, Zhu; Ye, Lin; Ren, Hongqiang

    2016-01-01

    To understand the diversity and abundance of antibiotic resistance genes (ARGs) in pharmaceutical wastewater treatment bioreactors, the ARGs in sludge from two full-scale pharmaceutical wastewater treatment plants (PWWTPs) were investigated and compared with sludge samples from three sewage treatment plants (STPs) using metagenomic approach. The results showed that the ARG abundances in PWWTP sludge ranged from 54.7 to 585.0 ppm, which were higher than those in STP sludge (27.2 to 86.4 ppm). Moreover, the diversity of ARGs in PWWTP aerobic sludge (153 subtypes) was higher than that in STP aerobic sludge (118 subtypes). In addition, it was found that the profiles of ARGs in PWWTP aerobic sludge were similar to those in STP aerobic sludge but different from those in PWWTP anaerobic sludge, suggesting that dissolve oxygen (DO) could be one of the important factors affecting the profiles of ARGs. In PWWTP aerobic sludge, aminoglycoside, sulfonamide and multidrug resistance genes were frequently detected. While, tetracycline, macrolide-lincosamide-streptogramin and polypeptide resistance genes were abundantly present in PWWTP anaerobic sludge. Furthermore, we investigated the microbial community and the correlation between microbial community and ARGs in PWWTP sludge. And, significant correlations between ARG types and seven bacterial genera were found. In addition, the mobile genetic elements (MGEs) were also examined and correlations between the ARGs and MGEs in PWWTP sludge were observed. Collectively, our results suggested that the microbial community and MGEs, which could be affected by DO, might be the main factors shaping the profiles of ARGs in PWWTP sludge.

  2. High Levels of Antibiotic Resistance Genes and Their Correlations with Bacterial Community and Mobile Genetic Elements in Pharmaceutical Wastewater Treatment Bioreactors.

    Directory of Open Access Journals (Sweden)

    Wenda Tao

    Full Text Available To understand the diversity and abundance of antibiotic resistance genes (ARGs in pharmaceutical wastewater treatment bioreactors, the ARGs in sludge from two full-scale pharmaceutical wastewater treatment plants (PWWTPs were investigated and compared with sludge samples from three sewage treatment plants (STPs using metagenomic approach. The results showed that the ARG abundances in PWWTP sludge ranged from 54.7 to 585.0 ppm, which were higher than those in STP sludge (27.2 to 86.4 ppm. Moreover, the diversity of ARGs in PWWTP aerobic sludge (153 subtypes was higher than that in STP aerobic sludge (118 subtypes. In addition, it was found that the profiles of ARGs in PWWTP aerobic sludge were similar to those in STP aerobic sludge but different from those in PWWTP anaerobic sludge, suggesting that dissolve oxygen (DO could be one of the important factors affecting the profiles of ARGs. In PWWTP aerobic sludge, aminoglycoside, sulfonamide and multidrug resistance genes were frequently detected. While, tetracycline, macrolide-lincosamide-streptogramin and polypeptide resistance genes were abundantly present in PWWTP anaerobic sludge. Furthermore, we investigated the microbial community and the correlation between microbial community and ARGs in PWWTP sludge. And, significant correlations between ARG types and seven bacterial genera were found. In addition, the mobile genetic elements (MGEs were also examined and correlations between the ARGs and MGEs in PWWTP sludge were observed. Collectively, our results suggested that the microbial community and MGEs, which could be affected by DO, might be the main factors shaping the profiles of ARGs in PWWTP sludge.

  3. Novel effects of dapagliflozin on epicardial adipose tissue with insulin resistance, high levels of inflammatory chemokines production and low differentiation ability.

    Science.gov (United States)

    Díaz-Rodríguez, Esther; Agra, Rosa M; Fernández, Ángel L; Adrio, B; García-Caballero, Tomás; González-Juanatey, José R; Eiras, Sonia

    2017-09-11

    In patients with cardiovascular disease, epicardial adipose tissue (EAT) is characterized by insulin resistance, high pro-inflammatory chemokines and low differentiation ability. Since dapagliflozin reduces body fat and cardiovascular events in diabetic patients, we wanted to know its effect on EAT and subcutaneous adipose tissue (SAT). Adipose samples were obtained from 52 patients undergoing heart surgery. Sodium-glucose cotransporter 2 (SGLT2) expression was determined by real time PCR (n = 20), Western blot and immunohistochemistry. Fat explants (n = 21) were treated with dapagliflozin and/or insulin. Glucose, free fatty acid, adipokines levels (by array) were measured in their secretomes which were tested on human coronary endothelial cells by wound healing assays. The effect of dapagliflozin effect on levels of glucose transporters in EAT explants was analysed by Western blot. Glucose uptake was also measured by fluorescence glucose (6NBDG) of differentiated stromal vascular cells from fat pads (n = 11). Finally, dapagliflozin-induced adipocytes differentiation was analysed by AdipoRed staining and perilipin levels. Results revealed SGLT2 expression in EAT. Dapagliflozin increased glucose uptake (20.95 ± 4.4 mg/dL vs. 12.97 ± 4.1 mg/dL; p effect on the healing of human coronary artery endothelial cells) and improved the differentiation of EAT cells. These results suggest a new protective pathway for this drug on EAT from patients with cardiovascular disease.

  4. Tellurite-exposed Escherichia coli exhibits increased intracellular {alpha}-ketoglutarate

    Energy Technology Data Exchange (ETDEWEB)

    Reinoso, Claudia A. [Departamento de Biologia, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, Santiago (Chile); Auger, Christopher; Appanna, Vasu D. [Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario (Canada); Vasquez, Claudio C., E-mail: claudio.vasquez@usach.cl [Departamento de Biologia, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, Santiago (Chile)

    2012-05-18

    Highlights: Black-Right-Pointing-Pointer Tellurite-exposed E. coli exhibits decreased {alpha}-KG dehydrogenase activity. Black-Right-Pointing-Pointer Cells lacking {alpha}-KGDH genes are more sensitive to ROS than isogenic, wt E. coli. Black-Right-Pointing-Pointer KG accumulation may serve to face tellurite-mediated oxidative damage in E. coli. -- Abstract: The tellurium oxyanion tellurite is toxic to most organisms because of its ability to generate oxidative stress. However, the detailed mechanism(s) how this toxicant interferes with cellular processes have yet to be fully understood. As part of our effort to decipher the molecular interactions of tellurite with living systems, we have evaluated the global metabolism of {alpha}-ketoglutarate a known antioxidant in Escherichia coli. Tellurite-exposed cells displayed reduced activity of the KG dehydrogenase complex (KGDHc), resulting in increased intracellular KG content. This complex's reduced activity seems to be due to decreased transcription in the stressed cells of sucA, a gene that encodes the E1 component of KGDHc. Furthermore, it was demonstrated that the increase in total reactive oxygen species and superoxide observed upon tellurite exposure was more evident in wild type cells than in E. coli with impaired KGDHc activity. These results indicate that KG may be playing a pivotal role in combating tellurite-mediated oxidative damage.

  5. Acoustic relaxation of some lead niobium tellurite glasses

    Indian Academy of Sciences (India)

    Abstract. The longitudinal ultrasonic attenuation in xNb2O5 −(1−x)TeO2, 0.1PbO − xNb2O5−(0.9−x)TeO2 and. 0.2PbO − xNb2O5− (0.8−x)TeO2 tellurite glass systems was measured using the pulse echo technique at ultrasonic frequencies 2, 4, 6 and 8 MHz in the temperature range from 150 to 300 K. The absorption ...

  6. High contrast ballistic imaging using femtosecond optical Kerr gate of tellurite glass.

    Science.gov (United States)

    Tan, Wenjiang; Zhou, Zhiguang; Lin, Aoxiang; Si, Jinhai; Zhan, Pingping; Wu, Bin; Hou, Xun

    2013-03-25

    We investigated the ballistic imaging technique using femtosecond optical Kerr gate of a tellurite glass. High contrast images of an object hidden behind turbid media were obtained. Compared to the conventional femtosecond optical Kerr gate using fused quartz, the optical Kerr gate using tellurite glass has more capacity to acquire high quality images of the object hidden behind a high optical density turbid medium. The experimental results indicated that the tellurite glass is a good candidate as the optical Kerr material for the ballistic imaging technique due to its large optical nonlinearity.

  7. Suppressing chromatic dispersion fluctuation for broadband optical parametric gain in highly nonlinear tellurite microstructured optical fibers

    Science.gov (United States)

    Tong, Hoang Tuan; Nguyen Phuoc, Trung Hoa; Suzuki, Takenobu; Ohishi, Yasutake

    2017-10-01

    We investigate the effect of chromatic dispersion fluctuation on the performance of fiber optical parametric amplification (FOPA) using tellurite hybrid microstructured optical fibers which have highly nonlinear coefficient and high freedom in tailoring chromatic dispersion. When a tellurite-glass buffer layer is added around the central core, the new tellurite hybrid microstructured optical fiber can suppress the fluctuation of chromatic dispersion which is caused by the variation in the core diameter and fiber transverse geometry. As a result, high signal gain and broad bandwidth of FOPA can be maintained.

  8. High-levels of acquired drug resistance in adult patients failing first-line antiretroviral therapy in a rural HIV treatment programme in KwaZulu-Natal, South Africa.

    Directory of Open Access Journals (Sweden)

    Justen Manasa

    Full Text Available To determine the frequency and patterns of acquired antiretroviral drug resistance in a rural primary health care programme in South Africa.Cross-sectional study nested within HIV treatment programme.Adult (≥ 18 years HIV-infected individuals initially treated with a first-line stavudine- or zidovudine-based antiretroviral therapy (ART regimen and with evidence of virological failure (one viral load >1000 copies/ml were enrolled from 17 rural primary health care clinics. Genotypic resistance testing was performed using the in-house SATuRN/Life Technologies system. Sequences were analysed and genotypic susceptibility scores (GSS for standard second-line regimens were calculated using the Stanford HIVDB 6.0.5 algorithms.A total of 222 adults were successfully genotyped for HIV drug resistance between December 2010 and March 2012. The most common regimens at time of genotype were stavudine, lamivudine and efavirenz (51%; and stavudine, lamivudine and nevirapine (24%. Median duration of ART was 42 months (interquartile range (IQR 32-53 and median duration of antiretroviral failure was 27 months (IQR 17-40. One hundred and ninety one (86% had at least one drug resistance mutation. For 34 individuals (15%, the GSS for the standard second-line regimen was <2, suggesting a significantly compromised regimen. In univariate analysis, individuals with a prior nucleoside reverse-transcriptase inhibitor (NRTI substitution were more likely to have a GSS <2 than those on the same NRTIs throughout (odds ratio (OR 5.70, 95% confidence interval (CI 2.60-12.49.There are high levels of drug resistance in adults with failure of first-line antiretroviral therapy in this rural primary health care programme. Standard second-line regimens could potentially have had reduced efficacy in about one in seven adults involved.

  9. Glassy State Lead Tellurite Nanobelts: Synthesis and Properties

    Directory of Open Access Journals (Sweden)

    Liu Hong

    2010-01-01

    Full Text Available Abstract The lead tellurite nanobelts have been first synthesized in the composite molten salts (KNO3/LiNO3 method, which is cost-effective, one-step, easy to control, and performed at low-temperature and in ambient atmosphere. Scanning electron microscopy, X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectrum, energy dispersive X-ray spectroscopy and FT-IR spectrum are used to characterize the structure, morphology, and composition of the samples. The results show that the as-synthesized products are amorphous and glassy nanobelts with widths of 200–300 nm and lengths up to tens of microns and the atomic ratio of Pb:Te:O is close to 1:1.5:4. Thermo-gravimetric analysis (TGA and differential scanning calorimetry (DSC and investigations of the corresponding structure and morphology change confirm that the nanobelts have low glass transition temperature and thermal stability. Optical diffuse reflectance spectrum indicates that the lead tellurite nanobelts have two optical gaps at ca. 3.72 eV and 4.12 eV. Photoluminescence (PL spectrum and fluorescence imaging of the products exhibit a blue emission (round 480 nm.

  10. Glass Transition Temperature- and Specific Volume- Composition Models for Tellurite Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Riley, Brian J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Vienna, John D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-09-01

    This report provides models for predicting composition-properties for tellurite glasses, namely specific gravity and glass transition temperature. Included are the partial specific coefficients for each model, the component validity ranges, and model fit parameters.

  11. Immobilization of Technetium Waste from Pyro-processing Using Tellurite Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Heo, Jong; Pyo, Jae-Young; Lee, Cheong-Won [POSTECH, Pohang (Korea, Republic of); Yang, Jae-Hwan; Park, Hwan-Seo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    Vitrification of Tc wastes has been challenging because of the low solubility in the silicate glass and high volatility in the melting process. In previous studies, the measured solubility of Tc and Re was ⁓ 3000 ppm at 1000 .deg. C in low activity waste (LAW) glass. And retention of Tc has been reported within 12 - 77% during the borosilicate vitrification process. Tellurite glasses have been studied for halide waste immobilization due to low melting temperatures (Tm= 600-800 .deg. C) and flexibility of network with foreign ions. Tellurite glasses offered higher halide retention than borosilicate glasses. The structure of pure tellurite (TeO{sub 2}) consists of TeO{sub 4} trigonal bipyramids (tbp), but TeO{sub 4} units are converted to TeO{sub 3} trigonal pyramids (tp) having non-bridging oxygen (NBO) as the modifiers added. Objectives of this study are to investigate the tellurite glasses for Tc immobilization using Re as a surrogate. Retention and waste loading of Re were analyzed during the vitrification process of tellurite glass. We investigated local structures of Re ions in glasses by Raman and X-ray absorption spectroscopies. The tellurite glass was investigated to immobilize the Ca(TcO{sub 4}){sub 2}, surrogated by Ca(ReO{sub 4}){sub 2}. The average of Re retention in tellurite glass was 86%. The 7-day PCT results were satisfied with U.S requirement up to 9 mass% of Ca(ReO{sub 4}){sub 2} content. Re in the tellurite glass exists +7 oxidation state and was coordinated with 4 oxygen.

  12. Multicolor upconversion emissions in Tm 3+/Er3+ codoped tellurite photonic microwire between silica fiber tapers.

    Science.gov (United States)

    Chen, Nan-Kuang; Kuan, Pei-Wen; Zhang, Junjie; Zhang, Liyan; Hu, Lili; Lin, Chinlon; Tong, Limin

    2010-12-06

    We report multicolor upconversion emissions including the blue-violet, green, and red lights in a Tm 3+/Er3+codoped tellurite glass photonic microwire between two silica fiber tapers. A silica fiber is tapered until its evanescent field is exposed and then angled-cleaved at the tapered center to divide the tapered fibers into two parts. A tellurite glass is melted by a gas flame to cluster into a sphere at the tip of one tapered fiber. The other angled-cleaved tapered fiber is blended into the melted tellurite glass. When the tellurite glass is melted, the two silica fiber tapers are simultaneously moving outwards to draw the tellurite glass into a microwire in between. The advantage of angled-cleaving on fiber tapers is to avoid cavity resonances in high index photonic microwire. Thus, the broadband white light can be transmitted between silica fibers and a special optical property like high intensity upconversion emission can be achieved. A cw 1064 nm Nd:YAG laser light is launched into the Tm 3+/Er3+ codoped tellurite microwire through a silica fiber taper to generate the multicolor upconversion emissions, including the blue-violet, green, and red lights, simultaneously.

  13. Characterization of Erbium-Doped Tellurite Glasses and Fibers

    Science.gov (United States)

    Marjanovic, Sasha; Toulouse, Jean; Dierolf, Volkmar; Sandmann, Christian; Himanshu, Jain; Kortan, Ahmet R.; Kopylov, Nonna; Ahrens, Robert G.

    2003-03-01

    The emission spectrum from erbium in new tellurite glasses is almost twice as broad as the corresponding spectrum in silica. We have carried out a study of these glasses using high resolution combined excitation-emission spectroscopy (CEES) and the erbium emission in fibers fabricated from the same glasses. Different lasing lines are observed corresponding to the erbium transitions identified in the CEES study. We show that specific lasing lines can be selected by adjusting the length of the fiber. A model is proposed for this length dependence. As the length of the fiber is increased, lower energy transitions contribute to the lasing since the scattering probability increases with the length. Emission spectra from both techniques show erbium transitions obeying selection rules calculated for these glasses.

  14. Characterization of Plasmid-Mediated Quinolone Resistance Determinants in High-Level Quinolone-Resistant Enterobacteriaceae Isolates from the Community: First Report of qnrD Gene in Algeria.

    Science.gov (United States)

    Yanat, Betitera; Machuca, Jesús; Díaz-De-Alba, Paula; Mezhoud, Halima; Touati, Abdelaziz; Pascual, Álvaro; Rodríguez-Martínez, José-Manuel

    2017-01-01

    The objective was to assess the prevalence of plasmid-mediated quinolone resistance (PMQR)-producing isolates in a collection of quinolone-resistant Enterobacteriaceae of community origin isolated in Bejaia, Algeria. A total of 141 nalidixic acid-resistant Enterobacteriaceae community isolates were collected in Bejaia (Northern Algeria) and screened for PMQR genes using polymerase chain reaction (PCR). For PMQR-positive strains, antimicrobial susceptibility testing was performed by broth microdilution and disk diffusion. Mutations in the quinolone resistance-determining regions of the target genes, gyrA and parC, were detected with a PCR-based method and sequencing. Southern blotting, conjugation and transformation assays and molecular typing by pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing were also performed. The prevalence of PMQR-producing Enterobacteriaceae isolates was 13.5% (19/141); 11 of these isolates produced Aac(6')-Ib-cr and 8 were qnr-positive (4 qnrB1-like, 2 qnrS1-like, and 2 qnrD1-like), including the association with aac(6')-Ib-cr gene in three cases. PMQR gene transfer by conjugation was successful in 6 of 19 isolates tested. PFGE revealed that most of the PMQR-positive Escherichia coli isolates were unrelated, except for two groups comprising two and four isolates, respectively, including the virulent multidrug-resistant clone E. coli ST131 that were clonally related. Our findings indicate that PMQR determinants are prevalent in Enterobacteriaceae isolates from the community studied. We describe the first report of the qnrD gene in Algeria.

  15. Increased high-level gentamicin resistance in invasive Enterococcus faecium is associated with aac(6')Ie-aph(2″)Ia-encoding transferable megaplasmids hosted by major hospital-adapted lineages.

    Science.gov (United States)

    Rosvoll, Torill C S; Lindstad, Belinda L; Lunde, Tracy M; Hegstad, Kristin; Aasnaes, Bettina; Hammerum, Anette M; Lester, Camilla H; Simonsen, Gunnar S; Sundsfjord, Arnfinn; Pedersen, Torunn

    2012-11-01

    Gentamicin is important in synergistic bactericidal therapy with cell wall agents for severe enterococcal infections. During 2003-2008, a 10-fold increase in the prevalence of high-level gentamicin resistance (HLGR), to above 50%, in blood culture isolates of Enterococcus faecium, was reported by the Norwegian Surveillance System for Antimicrobial Resistance. A representative national collection of invasive E. faecium isolates (n = 99) from 2008 was examined by a multilevel approach. Genotyping revealed a polyclonal population dominated by major hospital-associated lineages (mainly ST203, ST17, ST18, ST202 and ST192). The presence of aac(6')-Ie-aph(2″)-Ia, encoding the bi-functional aminoglycoside-modifying enzyme, was found in 98% of HLGR isolates (56/57). Furthermore, a significantly higher prevalence of potential virulence genes, toxin-antitoxin loci as well as pRE25 and pRUM type replicons was demonstrated in isolates belonging to major hospital-associated lineages compared to other sequence types. Megaplasmids of pLG1 replicon type (200-330 kb) were present in 90% of the isolates. Co-hybridization analyses revealed genetic linkage of aac(6')-Ie-aph(2″)-Ia to this replicon type. Transfer of HLGR-encoding plasmids was restricted to E. faecium. In conclusion, the increased prevalence of HLGR in invasive E. faecium in Norway is associated with hospital-adapted genetic lineages carrying aac(6')-Ie-aph(2″)-Ia-encoding transferable megaplasmids of the pLG1 replicon type. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  16. High level controls at RHIC

    Science.gov (United States)

    Peggs, S.; Saltmarsh, C.; Satogata, T.; Fryer, M.

    1994-12-01

    We report on the software tools and techniques in development to ensure that the commissioning and operations teams for RHIC have access to high level analysis, diagnosis, modelling and control functions early in the start up of the machine. The first tests will be for the sextant test in mid-1995.

  17. High-Level Radioactive Waste.

    Science.gov (United States)

    Hayden, Howard C.

    1995-01-01

    Presents a method to calculate the amount of high-level radioactive waste by taking into consideration the following factors: the fission process that yields the waste, identification of the waste, the energy required to run a 1-GWe plant for one year, and the uranium mass required to produce that energy. Briefly discusses waste disposal and…

  18. High-level Petri Nets

    DEFF Research Database (Denmark)

    High-level Petri nets are now widely used in both theoretical analysis and practical modelling of concurrent systems. The main reason for the success of this class of net models is that they make it possible to obtain much more succinct and manageable descriptions than can be obtained by means...... of low-level Petri nets - while, on the other hand, they still offer a wide range of analysis methods and tools. The step from low-level nets to high-level nets can be compared to the step from assembly languages to modern programming languages with an elaborated type concept. In low-level nets...... there is only one kind of token and this means that the state of a place is described by an integer (and in many cases even by a boolean). In high-level nets each token can carry a complex information/data - which, e.g., may describe the entire state of a process or a data base. Today most practical...

  19. RPython high-level synthesis

    Science.gov (United States)

    Cieszewski, Radoslaw; Linczuk, Maciej

    2016-09-01

    The development of FPGA technology and the increasing complexity of applications in recent decades have forced compilers to move to higher abstraction levels. Compilers interprets an algorithmic description of a desired behavior written in High-Level Languages (HLLs) and translate it to Hardware Description Languages (HDLs). This paper presents a RPython based High-Level synthesis (HLS) compiler. The compiler get the configuration parameters and map RPython program to VHDL. Then, VHDL code can be used to program FPGA chips. In comparison of other technologies usage, FPGAs have the potential to achieve far greater performance than software as a result of omitting the fetch-decode-execute operations of General Purpose Processors (GPUs), and introduce more parallel computation. This can be exploited by utilizing many resources at the same time. Creating parallel algorithms computed with FPGAs in pure HDL is difficult and time consuming. Implementation time can be greatly reduced with High-Level Synthesis compiler. This article describes design methodologies and tools, implementation and first results of created VHDL backend for RPython compiler.

  20. Process for solidifying high-level nuclear waste

    Science.gov (United States)

    Ross, Wayne A.

    1978-01-01

    The addition of a small amount of reducing agent to a mixture of a high-level radioactive waste calcine and glass frit before the mixture is melted will produce a more homogeneous glass which is leach-resistant and suitable for long-term storage of high-level radioactive waste products.

  1. Energy Transfer Process of Eu3+ Ions Doped in Tellurite Glass

    Science.gov (United States)

    Hong, Tran Thi; Dung, Phan Tien; Quang, Vu Xuan

    2016-05-01

    Tellurite glass doped with different concentrations of Eu3+ ions has been prepared by the conventional melting process. Photoluminescence, Raman spectra, phonon side-band spectra, and Judd-Ofelt analysis were carried out. Some spectroscopic parameters were estimated to predict the luminescence efficiency of the materials. The energy transfer between the rare-earth ions was observed, and a model for its cross-relaxation was proposed and quantitatively estimated. The charged intrinsic defects in the form of nonbridging oxygen (NBO) were determined, and the energy transfer between NBO and rare-earth ions observed. The energy-transfer-induced Eu3+ photoluminescence enhancement in tellurite glass is studied.

  2. The CMS High Level Trigger

    CERN Document Server

    Gori, Valentina

    2014-01-01

    The CMS experiment has been designed with a 2-level trigger system: the Level 1 Trigger, implemented on custom-designed electronics, and the High Level Trigger (HLT), a streamlined version of the CMS offline reconstruction software running on a computer farm. A software trigger system requires a tradeoff between the complexity of the algorithms running on the available computing power, the sustainable output rate, and the selection efficiency. Here we will present the performance of the main triggers used during the 2012 data taking, ranging from simpler single-object selections to more complex algorithms combining different objects, and applying analysis-level reconstruction and selection. We will discuss the optimisation of the triggers and the specific techniques to cope with the increasing LHC pile-up, reducing its impact on the physics performance.

  3. The CMS High Level Trigger

    CERN Document Server

    Trocino, Daniele

    2014-01-01

    The CMS experiment has been designed with a 2-level trigger system: the Level 1 Trigger, implemented in custom-designed electronics, and the High Level Trigger (HLT), a streamlined version of the CMS offline reconstruction software running on a computer farm. A software trigger system requires a tradeoff between the complexity of the algorithms running with the available computing power, the sustainable output rate, and the selection efficiency. We present the performance of the main triggers used during the 2012 data taking, ranging from simple single-object selections to more complex algorithms combining different objects, and applying analysis-level reconstruction and selection. We discuss the optimisation of the trigger and the specific techniques to cope with the increasing LHC pile-up, reducing its impact on the physics performance.

  4. Femtosecond laser written optical waveguide amplifier in phospho-tellurite glass.

    Science.gov (United States)

    Fernandez, T Toney; Eaton, S M; Della Valle, G; Vazquez, R Martinez; Irannejad, M; Jose, G; Jha, A; Cerullo, G; Osellame, R; Laporta, P

    2010-09-13

    We report on the first demonstration of an optical waveguide amplifier in phospho-tellurite glass providing net gain at 1.5 μm. The device was fabricated using a high repetition rate femtosecond laser and exhibited internal gain across 100-nm bandwidth covering the entire C + L telecom bands.

  5. Optimizing High Level Waste Disposal

    Energy Technology Data Exchange (ETDEWEB)

    Dirk Gombert

    2005-09-01

    If society is ever to reap the potential benefits of nuclear energy, technologists must close the fuel-cycle completely. A closed cycle equates to a continued supply of fuel and safe reactors, but also reliable and comprehensive closure of waste issues. High level waste (HLW) disposal in borosilicate glass (BSG) is based on 1970s era evaluations. This host matrix is very adaptable to sequestering a wide variety of radionuclides found in raffinates from spent fuel reprocessing. However, it is now known that the current system is far from optimal for disposal of the diverse HLW streams, and proven alternatives are available to reduce costs by billions of dollars. The basis for HLW disposal should be reassessed to consider extensive waste form and process technology research and development efforts, which have been conducted by the United States Department of Energy (USDOE), international agencies and the private sector. Matching the waste form to the waste chemistry and using currently available technology could increase the waste content in waste forms to 50% or more and double processing rates. Optimization of the HLW disposal system would accelerate HLW disposition and increase repository capacity. This does not necessarily require developing new waste forms, the emphasis should be on qualifying existing matrices to demonstrate protection equal to or better than the baseline glass performance. Also, this proposed effort does not necessarily require developing new technology concepts. The emphasis is on demonstrating existing technology that is clearly better (reliability, productivity, cost) than current technology, and justifying its use in future facilities or retrofitted facilities. Higher waste processing and disposal efficiency can be realized by performing the engineering analyses and trade-studies necessary to select the most efficient methods for processing the full spectrum of wastes across the nuclear complex. This paper will describe technologies being

  6. Effect of ZnO on the Thermal Properties of Tellurite Glass

    Directory of Open Access Journals (Sweden)

    H. A. A. Sidek

    2013-01-01

    Full Text Available Systematic series of binary zinc tellurite glasses in the form (ZnOx(TeO2 (where x=0 to 0.4 with an interval of 0.05 mole fraction have been successfully prepared via conventional melt cast-quenching technique. Their density was determined by Archimedes method with acetone as buoyant liquid. The thermal expansion coefficient of each zinc tellurite glasses was measured using L75D1250 dilatometer, while their glass transition temperature (Tg was determined by the SETARAM Labsys DTA/6 differential thermogravimetric analysis at a heating rate of 20 K min−1. The acoustic Debye temperature and the softening temperature (Ts were estimated based on the longitudinal (VL and shear ultrasonic (Vs wave velocities propagated in each glass sample. For ultrasonic velocity measurement of the glass sample, MATEC MBS 8000 Ultrasonic Data Acquisition System was used. All measurements were taken at 10 MHz frequency and at room temperature. All the thermal properties of such binary tellurite glasses were measured as a function of ZnO composition. The composition dependence was discussed in terms of ZnO modifiers that were expected to change the thermal properties of tellurite glasses. Experimental results show their density, and the thermal expansion coefficient increases as more ZnO content is added to the tellurite glass network, while their glass transition, Debye temperature, and the softening temperature decrease due to a change in the coordination number (CN of the network forming atoms and the destruction of the network structure brought about by the formation of some nonbridging oxygen (NBO atoms.

  7. Effectiveness and cost-effectiveness of potential responses to future high levels of transmitted HIV drug resistance in antiretroviral drug-naive populations beginning treatment: modelling study and economic analysis

    Science.gov (United States)

    Phillips, Andrew N; Cambiano, Valentina; Miners, Alec; Revill, Paul; Pillay, Deenan; Lundgren, Jens D; Bennett, Diane; Raizes, Elliott; Nakagawa, Fumiyo; De Luca, Andrea; Vitoria, Marco; Barcarolo, Jhoney; Perriens, Joseph; Jordan, Michael R; Bertagnolio, Silvia

    2016-01-01

    Summary Background With continued roll-out of antiretroviral therapy (ART) in resource-limited settings, evidence is emerging of increasing levels of transmitted drug-resistant HIV. We aimed to compare the effectiveness and cost-effectiveness of different potential public health responses to substantial levels of transmitted drug resistance. Methods We created a model of HIV transmission, progression, and the effects of ART, which accounted for resistance generation, transmission, and disappearance of resistance from majority virus in the absence of drug pressure. We simulated 5000 ART programmatic scenarios with different prevalence levels of detectable resistance in people starting ART in 2017 (t0) who had not previously been exposed to antiretroviral drugs. We used the model to predict cost-effectiveness of various potential changes in policy triggered by different prevalence levels of resistance to non-nucleoside reverse transcriptase inhibitors (NNRTIs) measured in the population starting ART. Findings Individual-level resistance testing before ART initiation was not generally a cost-effective option, irrespective of the cost-effectiveness threshold. At a cost-effectiveness threshold of US$500 per quality-adjusted life-year (QALY), no change in policy was cost effective (ie, no change in policy would involve paying less than $500 per QALY gained), irrespective of the prevalence of pretreatment NNRTI resistance, because of the increased cost of the policy alternatives. At thresholds of $1000 or higher, and with the prevalence of pretreatment NNRTI resistance greater than 10%, a policy to measure viral load 6 months after ART initiation became cost effective. The policy option to change the standard first-line treatment to a boosted protease inhibitor regimen became cost effective at a prevalence of NNRTI resistance higher than 15%, for cost-effectiveness thresholds greater than $2000. Interpretation Cost-effectiveness of potential policies to adopt in response

  8. In Vitro Activity of the New Fluoroketolide Solithromycin (CEM-101) against a Large Collection of Clinical Neisseria gonorrhoeae Isolates and International Reference Strains, Including Those with High-Level Antimicrobial Resistance: Potential Treatment Option for Gonorrhea?

    Science.gov (United States)

    Golparian, Daniel; Fernandes, Prabhavathi; Ohnishi, Makoto; Jensen, Jörgen S.

    2012-01-01

    Gonorrhea may become untreatable, and new treatment options are essential. We investigated the in vitro activity of the first fluoroketolide, solithromycin. Clinical Neisseria gonorrhoeae isolates and reference strains (n = 246), including the two extensively drug-resistant strains H041 and F89 and additional isolates with clinical cephalosporin resistance and multidrug resistance, were examined. The activity of solithromycin was mainly superior to that of other antimicrobials (n = 10) currently or previously recommended for gonorrhea treatment. Solithromycin might be an effective treatment option for gonorrhea. PMID:22354296

  9. Optical aging observation in suspended core tellurite microstructured fibers under atmospheric conditions

    Science.gov (United States)

    Strutynski, C.; Mouawad, O.; Picot-Clémente, J.; Froidevaux, P.; Désévédavy, F.; Gadret, G.; Jules, J.-C.; Kibler, B.; Smektala, F.

    2017-11-01

    Tellurite glasses are good candidates for the development of broadband supercontinuum (SC) laser sources in the 1-5 μm range. At the moment, beside very few exceptions, SC generation in TeO2-based microstructured optical fibers (MOFs) is limited to 3 μm in the mid-infrared (MIR). We present here an observation of an optical aging occurring in six-hole suspended-core tellurite MOFs. When exposed to atmospheric conditions, such fibers show an alteration of their transmission between 3 and 4 μm. This aging phenomenon leads to the growth of strong additional losses in this wavelengths range over time. Impact of the transmission degradation on spectral broadening is studied through numerical simulations of SC generation.

  10. Luminescence Enhancement in Eu(III-Doped Tellurite Glass Embedded Silver Nanoparticles

    Directory of Open Access Journals (Sweden)

    M. Reza Doustia

    2013-12-01

    Full Text Available Introduction of the metallic nanoparticles (NPs in the bulk glass received a large interest due to their versatile applications. The effect of silver NPs on optical properties of the Eu3+-doped zinc tellurite glasses is presented for the first time. Glass samples are prepared by melt-quenching technique. The surface plasmon absorption bands of silver NPs are recorded in the visible region. The enhancements in the order of 2.2-2.4 times are observed in the luminescence of the Eu3+ ions by introduction of silver NPs up to 1 mol% and are attributed to contribution of the NPs with average size of about 8 nm. In addition, energy transfer from surface of the metal to the rare earth ion is discussed as the second channel for the enhancement. This report highlights the excellent performance of tellurite glasses for applications such as LEDs, color displays and nanophotonics.

  11. Assessment of lead tellurite glass for immobilizing electrochemical salt wastes from used nuclear fuel reprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Riley, Brian J.; Kroll, Jared O.; Peterson, Jacob A.; Pierce, David A.; Ebert, William L.; Williams, Benjamin D.; Snyder, Michelle M. V.; Frank, Steven M.; George, Jaime L.; Kruska, Karen

    2017-11-01

    This paper provides an overview of research evaluating the use of lead tellurite glass as a waste form for salt wastes from electrochemical reprocessing of used nuclear fuel. The efficacy of using lead tellurite glass to immobilize three different salt compositions was evaluated: a LiCl-Li2O oxide reduction salt containing fission products from oxide fuel, a LiCl-KCl eutectic salt containing fission products from metallic fuel, and SrCl2. Physical and chemical properties of glasses made with these salts were characterized with X-ray diffraction, bulk density measurements, differential thermal analysis, chemical durability tests, scanning and transmission electron microscopies, and energy-dispersive X-ray spectroscopy. These glasses were found to accommodate high salt concentrations and have high densities, but further development is needed to improve chemical durability. (C) 2017 Published by Elsevier B.V.

  12. Analysis of 750 nm laser emission of Ho 3+ in tellurite, germanate and phosphate glasses

    Science.gov (United States)

    Reisfeld, R.; Kalisky, Y.

    1980-11-01

    Time evolution of the 5F 45S 2 → 5I 8 fluorescence of Ho 3+-doped zinc tellurite glasses was studied from 37 to 300 K. The time needed to achieve equilibrium between 5F 4 and 5S 2 states is 0.6 μs. Multiphonon relaxation from 5F 4, 5S 2 and 5F 5 levels of Ho 3+ in zinc tellurite was studied. Two types of phonons were found to be effective. It is expected that at low temperature (37 K), laser emission, mainly from the 5S 2 level, will be obtained with a cross section of 2.78 × 10 -20 cm 2. Yet at room temperature laser emission from 5F 4 or 5S 2 can be obtained.

  13. Gain-assisted superluminal propagation in tellurite glass fiber based on stimulated Brillouin scattering.

    Science.gov (United States)

    Song, Kwang Yong; Abedin, Kazi S; Hotate, Kazuo

    2008-01-07

    We demonstrate superluminal propagation of optical pulses with amplification in optical fibers based on stimulated Brillouin scattering. A triple gain peak configuration is used for the generation of narrowband anomalous dispersion in 2 m tellurite glass fiber, where the group index change as much as -1.19 is achieved with 6.9 dB amplification in 34 ns Gaussian pulses, leading to the group index of 0.84.

  14. Global transcriptomic analysis uncovers a switch to anaerobic metabolism in tellurite-exposed Escherichia coli.

    Science.gov (United States)

    Molina-Quiroz, Roberto C; Loyola, David E; Díaz-Vásquez, Waldo A; Arenas, Felipe A; Urzúa, Ulises; Pérez-Donoso, José M; Vásquez, Claudio C

    2014-09-01

    Tellurite (TeO3(2-)) is harmful for most microorganisms, especially Gram-negative bacteria. Even though tellurite toxicity involves a number of individual aspects, including oxidative stress, malfunctioning of metabolic enzymes and a drop in the reduced thiol pool, among others, the general mechanism of toxicity is rather complex and not completely understood to date. This work focused on DNA microarray analysis to evaluate the Escherichia coli global transcriptomic response when exposed to the toxicant. Confirming previous results, the induction of the oxidative stress response regulator soxS was observed. Upregulation of a number of genes involved in the global stress response, protein folding, redox processes and cell wall organization was also detected. In addition, downregulation of aerobic respiration-related genes suggested a metabolic switch to anaerobic respiration. The expression results were validated through oxygen consumption experiments, which corroborated that tellurite-exposed cells effectively consume oxygen at lower rates than untreated controls. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  15. Increasing prevalence of wildtypes in the dihydrofolate reductase gene of Plasmodium falciparum in an area with high levels of sulfadoxine/pyrimethamine resistance after introduction of treated bed nets

    DEFF Research Database (Denmark)

    Alifrangis, Michael; Lemnge, Martha M; Rønn, Anita M

    2003-01-01

    In Magoda and Mpapayu villages in Tanzania, we have previously found comparable high prevalence of Plasmodium falciparum resistance to sulfadoxine/pyrimethamine (S/P) in vivo and of mutations in the dihydrofolate reductase (dhfr) and dihydropteroate synthetase (dhps) genes of P. falciparum respon...... than in Mpapayu in 2000. The impact of ITNs on the transmission intensity seems not only to affect the overall malaria morbidity, but may even facilitate restoration of susceptibility to antimalarial drugs....

  16. Design and analysis of single-mode tellurite photonic crystal fibers for stimulated Brillouin scattering based slow-light generation.

    Science.gov (United States)

    Jain, Varsha; Sharma, Shubham; Saini, Than Singh; Kumar, Ajeet; Sinha, Ravindra Kumar

    2016-09-01

    We theoretically examine two designs of single-mode (i) Er-doped tellurite and (ii) undoped tellurite photonic crystal fiber (PCF) for generation of slow light with tunable features based on stimulated Brillouin scattering. We obtained (i) Brillouin gain up to 91 dB and time delay of ∼145  ns at maximum allowable pump power of ∼775  mW in a 2 m Er-doped tellurite PCF and (ii) Brillouin gain up to ∼88  dB and time delay of ∼154  ns at maximum allowable pump power ∼21  mW in a 100 m undoped tellurite photonic crystal fiber. Simulated results clearly indicate that the doped tellurite PCF with Er enhances the maximum allowable pump power and comparable time delay can be obtained even with reduced photonic crystal fiber length. We believe that the carried out examination and simulation have potential impact on design and development of slow-light-based photonic devices applicable in telecommunication systems, enhancement of optical forces, and quantum computing.

  17. High-level language computer architecture

    CERN Document Server

    Chu, Yaohan

    1975-01-01

    High-Level Language Computer Architecture offers a tutorial on high-level language computer architecture, including von Neumann architecture and syntax-oriented architecture as well as direct and indirect execution architecture. Design concepts of Japanese-language data processing systems are discussed, along with the architecture of stack machines and the SYMBOL computer system. The conceptual design of a direct high-level language processor is also described.Comprised of seven chapters, this book first presents a classification of high-level language computer architecture according to the pr

  18. Elaboration and optimization of tellurite-based materials for raman gain application

    Science.gov (United States)

    Guery, Guillaume

    Tellurite-based oxide glasses have been investigated as promising materials for Raman gain applications, due to their good linear and nonlinear optical properties and their wide transparency windows in the near- and midwave infrared spectral region. Furthermore, their interesting thermal properties, i.e. low glass transition temperature and ability to be drawn into optical fibers, make tellurite-based glasses excellent candidates for optical fiber amplifiers. The estimation of the strength and spectral distribution of Raman gain in materials is commonly approximated from the spontaneous Raman scattering cross-section measurement. For development of tellurite-based glasses as Raman amplifiers, understanding the relationship between glass structure, vibrational response, and nonlinear optical properties (NLO) represents a key point. This dissertation provides an answer to the fundamental question of the PhD study: "What is the impact of the glass structure on Raman gain properties of tellurite glasses?" This dissertation summarizes findings on different tellurite-based glass families: the TeO2-TaO5/2-ZnO, TeO2-BiO 3/2-ZnO and TeO2-NbO5/2 glass networks. The influence of glass modifiers has been shown on the glass' properties. Introduction of tantalum oxide or zinc oxide has been shown to increase the glass' stability against crystallization, quantified by DeltaT, where DeltaT = Tx -Tg. Added to the variation of the glass viscosity, this attribute is critical in fabricating optical fibers and for the use of these materials in fiber-based Raman gain applications. The role of ZnO in the tellurite network and the mechanism for structural modification has been determined. This addition results in not only the largest DeltaT reported for these highly nonlinear glasses to date, but coincides with a commensurate decrease of the refractive index. A hydroxyl purification has been developed that when employed, resulted in high purity preform materials exhibiting a limited

  19. SIGWX Charts - High Level Significant Weather

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — High level significant weather (SIGWX) forecasts are provided for the en-route portion of international flights. NOAA's National Weather Service Aviation Center...

  20. High-Level Dialogue on International Migration

    Directory of Open Access Journals (Sweden)

    UNHCR

    2006-08-01

    Full Text Available UNHCR wishes to bring the following observations andrecommendations to the attention of the High-LevelDialogue (HLD on International Migration and Development,to be held in New York, 14-15 September 2006:

  1. Overview of high level synthesis tools

    CERN Document Server

    Evans, J

    2011-01-01

    High Level Synthesis takes an abstract behavioural or algorithmic description of a digital system and creates a register transfer level structure that realises the described behaviour. Various methodologies have been developed to perform such synthesis tasks. This paper presents the different HLS concepts used in the current leading tools. It makes a comparison between the different approaches and highlights their advantages and limitations. We also present a high level synthesis example.

  2. Measurement of the nonlinear refractive index of tellurite glass fiber by using induced grating autocorrelation technique

    Science.gov (United States)

    Traore, Aboubakar

    Nonlinear phenomena in optical fibers have been attracting considerable attention because of the rapid growth of the fiber optics communication industry. The increasing demand in internet use and the expansion of telecommunications in the developing world have triggered the need for high capacity and ultra-fast communication devices and also the need to increase the number of transmission channels in the fibers. Wavelength Division Multiplexing (WDM) and Dense Wavelength Division Multiplexing (DWDM) systems are capable of transmitting large volumes of data at very high rates into huge numbers of optical transmission channels. This ability is limited by the gain bandwidth of Silica based fiber optics amplifiers already installed in the communication networks. Tellurite based fiber amplifiers offer the necessary bandwidth for amplification of WDM and DWDM channels. To investigate the nonlinear properties of the optical fibers in this research, we used a 10 picoseconds pulse width passively mode-locked Nd:Vanadate ( Nd:YVO4) laser operating at 1342nm with a repetition rate of 76 MHz. We accurately measured the nonlinear refractive index of single mode silica fibers utilizing the Induced Grating Autocorrelation (IGA) technique. IGA technique was extended furthermore to study nonlinear effects in multimode fibers, and for the first time, we successfully measured the nonlinear refractive index (n2) of a multimode silica fiber. Confident of the ability of IGA technique for determining n 2 of multimode silica fibers, we measured the nonlinear refractive index of multimode Tellurite glass fibers with length as short as 0.5 meter. The goal of this work is to provide accurate and reliable information on the nonlinear optical properties of Tellurite glass fibers, novel fibers with promising future for developing ultrafast and high transmission capacity communication devices.

  3. Enhanced broadband near-infrared luminescence from Pr3+-doped tellurite glass with silver nanoparticles

    Science.gov (United States)

    Cheng, Pan; Zhou, Yaxun; Zhou, Minghan; Su, Xiue; Zhou, Zizhong; Yang, Gaobo

    2017-11-01

    Pr3+-doped tellurite glasses containing metallic silver NPs were synthesized by the conventional melt-quenching technique. Structural, thermal and optical properties of the synthesized glass samples were characterized by X-Ray diffraction (XRD) curves, Raman spectra, differential scanning calorimeter (DSC) curves, transmission electron microscopy (TEM) images, UV/Vis/NIR absorption and near-infrared fluorescence emission spectra. The XRD curves confirmed the amorphous structural nature of the synthesized glasses, the Raman spectra identified the presence of different vibrational groups, the DSC curves verified the good thermal stability, and the TEM images revealed the nucleated silver NPs with average diameter about 10 nm dispersed in the glass matrix and its surface Plasmon resonance (SPR) absorption band was located at around 510 nm. Besides, Judd-Ofelt intensity parameters Ωt (t = 2, 4, 6) and other important spectroscopic parameters like transition probability, radiative lifetime, branching ratio were calculated to evaluate the radiative properties of Pr3+ levels from the measured optical absorption spectra. It was found that Pr3+-doped tellurite glasses could emit an ultra-broadband fluorescence extending from 1250 to 1650 nm under the 488 nm excitation, and this fluorescence emission increased further with the introduction of silver NPs. The enhanced fluorescence was mainly attributed to the increased local electric field around Pr3+ induced by silver NPs. The present results demonstrate that Pr3+-Ag codoped tellurite glass is a promising candidate for the near-infrared band ultra-broadband fiber amplifiers covering the expanded low-loss communication window.

  4. Luminescence studies on Dy3+ doped calcium boro-tellurite glasses for White light applications

    Science.gov (United States)

    Karthikeyan, P.; Vijayakumar, R.; Marimuthu, K.

    2017-09-01

    A new series of Dy3+ doped calcium boro-tellurite glasses have been prepared by melt quenching technique and their spectroscopic properties were studied through FTIR, absorption luminescence and lifetime spectral measurements. FTIR studies have been made to explore the presence of various stretching and bending vibrations of different borate and tellurite groups in the prepared glasses. The bonding parameter values were estimated from the absorption band positions using Nephelauxetic ratios to examine the nature of the metal-ligand bond. The optical band gap and Urbach energy (ΔE) values were obtained from the absorption spectra to explore the electronic band structure of the studied glasses. Judd-Ofelt (JO) theory have been used to determine the JO intensity parameters (Ω2, Ω4, Ω6) following the least square fitting procedure between the experimental and calculated oscillator strength values. The luminescence spectra of the Dy3+ doped calcium boro-tellurite glasses exhibit two intense emission bands corresponding to the 4F9/2→6H15/2 and 4F9/2→6H13/2 transitions. Further, they exhibit less intense emission band due to the 4F9/2→6H11/2 transition. Luminescence spectra were characterized through CIE 1931 chromaticity diagram to obtain the dominant emission color of the prepared glasses. The JO intensity parameters and refractive index values have been used to calculate the radiative parameters such as transition probabilities (AR), branching ratios (βR) and stimulated emission cross-section (σPE) values for the observed transitions in the luminescence spectra. The decay curves of all the studied glasses found to exhibit non-exponential behavior and further to understand the energy transfer process takes place between the Dy3+ ions, the decay curves were fitted to the Inokuti-Hirayama (IH) model. The structural and optical properties of the Dy3+ doped calcium boro-tellurite glasses have been studied as a function of different metal cations (Zn, Cd, Pb and

  5. EAP high-level product architecture

    DEFF Research Database (Denmark)

    Guðlaugsson, Tómas Vignir; Mortensen, Niels Henrik; Sarban, Rahimullah

    2013-01-01

    the function of the EAP transducers to be changed, by basing the EAP transducers on a different combination of organ alternatives. A model providing an overview of the high level product architecture has been developed to support daily development and cooperation across development teams. The platform approach...... of EAP technology products while keeping complexity under control. High level product architecture has been developed for the mechanical part of EAP transducers, as the foundation for platform development. A generic description of an EAP transducer forms the core of the high level product architecture....... This description breaks down the EAP transducer into organs that perform the functions that may be present in an EAP transducer. A physical instance of an EAP transducer contains a combination of the organs needed to fulfill the task of actuator, sensor, and generation. Alternative principles for each organ allow...

  6. High-Level Application Framework for LCLS

    Energy Technology Data Exchange (ETDEWEB)

    Chu, P; Chevtsov, S.; Fairley, D.; Larrieu, C.; Rock, J.; Rogind, D.; White, G.; Zalazny, M.; /SLAC

    2008-04-22

    A framework for high level accelerator application software is being developed for the Linac Coherent Light Source (LCLS). The framework is based on plug-in technology developed by an open source project, Eclipse. Many existing functionalities provided by Eclipse are available to high-level applications written within this framework. The framework also contains static data storage configuration and dynamic data connectivity. Because the framework is Eclipse-based, it is highly compatible with any other Eclipse plug-ins. The entire infrastructure of the software framework will be presented. Planned applications and plug-ins based on the framework are also presented.

  7. Spectroscopy of Yb-doped tungsten-tellurite glass and assessment of its lasing properties

    Science.gov (United States)

    Merzliakov, M. A.; Kouhar, V. V.; Malashkevich, G. E.; Pestryakov, E. V.

    2018-01-01

    Glasses of the TeO2-WO3-Yb2O3 system are synthesized for wide range of Yb3+ concentrations of up to 6.0 × 1021 ions/cm3. The spectral-luminescent properties of lightly doped samples are investigated at room temperature and at the boiling point of liquid nitrogen. The energies of the Stark levels of the ground and excited states of Yb3+ ions incorporated into tungsten-tellurite glass are determined by analyzing the low-temperature spectra. The absorption, emission, and gain cross section spectra are obtained. The excess of the measured fluorescence decay time over the radiative lifetime ∼0.3 ms derived from the absorption spectra is attributed to the reabsorption effect in bulk samples. Measurements of lightly doped glass powder in the immersion liquid are made to reduce the effect of reabsorption. The fluorescence decay time of the powder is very close to the calculated radiative lifetime. Compared with phosphate, silicate, and other Yb3+-doped glasses, the tungsten-tellurite glass has a promising potential as a gain medium for lasers and amplifiers.

  8. NIR emission studies and dielectric properties of Er(3+)-doped multicomponent tellurite glasses.

    Science.gov (United States)

    Sajna, M S; Thomas, Sunil; Jayakrishnan, C; Joseph, Cyriac; Biju, P R; Unnikrishnan, N V

    2016-05-15

    Multicomponent tellurite glasses containing altered concentrations of Er2O3 (ranging from 0 to 1 mol%) were prepared by the standard melt quenching technique. Investigations through energy dispersive X-ray spectroscopy (EDS), Raman scattering spectroscopy, Fourier transform infrared (FTIR) spectroscopy, near-infrared (NIR) emission studies and dielectric measurement techniques were done to probe their compositional, structural, spectroscopic and dielectric characteristics. The broad emission together with the high values of the effective linewidth (~63 nm), stimulated emission cross-section (9.67 × 10(-21) cm(2)) and lifetime (2.56 ms) of (4)I13/2 level for 0.5 mol% of Er(3+) makes these glasses attractive for broadband amplifiers. From the measured capacitance and dissipation factor, the relative permittivity, dielectric loss and the conductivity were computed; which furnish the dielectric nature of the multicomponent tellurite glasses that depend on the applied frequency. Assuming the ideal Debye behavior as substantiated by Cole-Cole plot, an examination of the real and imaginary parts of impedance was performed. The power-law and Cole-Cole parameters were resolved for all the glass samples. From the assessment of the emission analysis and dielectric properties of the glass samples, it was obvious that the Er(3+) ion concentration had played a vital role in tuning the optical and dielectric properties and the 0.5 mol% of Er(3+) -doped glass was confirmed as the optimum composition. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Crystallisation behavior and electronic conductivity of vanadium tellurite glass-ceramics

    DEFF Research Database (Denmark)

    Kjeldsen, Jonas; Yue, Yuanzheng; Rodrigues, A.C.M.

    2012-01-01

    The electrodes of secondary batteries degrade during consecutive intercalation cycles, thus reducing the units’ capacity. The amorphous nature of an electrode could theoretically lower the degree of such degradation. Since a vanadium tellurite system exhibit high electronic conductivity and the a......The electrodes of secondary batteries degrade during consecutive intercalation cycles, thus reducing the units’ capacity. The amorphous nature of an electrode could theoretically lower the degree of such degradation. Since a vanadium tellurite system exhibit high electronic conductivity...... and the ability to intercalate lithium-ions, it is a candidate for usage as cathode material. In the present work, we optimize the electronic conductivity of the congruent 2TeO2-V2O5 composition by tuning both the redox state of the vanadium and the overall degree of crystallinity. Amorphous 2TeO2-V2O5...... temperature of synthesis, and it is measured by electron paramagnetic resonance spectroscopy. The electronic conductivity is measured by impedance spectroscopy in the temperature range from 298 to 523 K. The results indicate that the electronic conductivity is independent of the degree of crystallinity...

  10. PAIRWISE BLENDING OF HIGH LEVEL WASTE (HLW)

    Energy Technology Data Exchange (ETDEWEB)

    CERTA, P.J.

    2006-02-22

    The primary objective of this study is to demonstrate a mission scenario that uses pairwise and incidental blending of high level waste (HLW) to reduce the total mass of HLW glass. Secondary objectives include understanding how recent refinements to the tank waste inventory and solubility assumptions affect the mass of HLW glass and how logistical constraints may affect the efficacy of HLW blending.

  11. The Effects of High Level Infrasound

    Science.gov (United States)

    1980-02-01

    This paper will attempt to survey the current knowledge on the effects of relative high levels of infrasound on humans. While this conference is...8217Is hearing the main concern of infrasound and low frequency exposure, or is there a more sensitive mechanism?’. It would be comforting to know that

  12. Enhanced 2.7 μm emission of Er{sup 3+}-doped low hydroxyl fluoroaluminate–tellurite glass

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Feifei; Ma, Yaoyao; Liu, Liwan [Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Hu, Lili; Chen, Danping [Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2015-02-15

    New fluoroaluminate–tellurite glasses with high thermal stability were fabricated through introducing TeO{sub 2} into the fluoroaluminate glass (AlF{sub 3}–YF{sub 3}–CaF{sub 2}–BaF{sub 2}–SrF{sub 2}–MgF{sub 2}). 2.7 μm emission properties were investigated through the measured absorption and emission spectra. For the first time it was found that the OH{sup −} absorption coefficient at 2.84 μm was reduced to 1/15 for the fluoride system by introducing TeO{sub 2}. X-ray diffraction showed that the sample without TeO{sub 2} composition showed some crystallization phases when the glass was reheated. However, the addition of TeO{sub 2} changed the crystallization mechanism and improved the glass forming ability of the fluoroaluminate glass. Enhanced 2.7 μm emission was observed in the fluoroaluminate–tellurite glass under 980 nm excitation and the calculated spontaneous transition probability (A), branching ratio (β) and emission cross section (σ{sub em}) were larger than some reported values. These results indicate that this kind of fluoroaluminate–tellurite glass has potential applications as host material for 2.7 μm lasers. - Highlights: • New fluoroaluminate–tellurite glasses with high thermal stability were fabricated. • The absorption coefficient of OH{sup −} at about 3 μm was reduced to 1/15 for the fluoride system by introducing TeO{sub 2}. • Enhanced 2.7 μm emission was observed in the fluoroaluminate–tellurite glass under 980 nm excitation. • Calculated spontaneous transition and emission cross sections were as large as 25.52 s{sup −1} and 0.75×10{sup −20} cm{sup 2} respectively.

  13. High-Level Waste Melter Study Report

    Energy Technology Data Exchange (ETDEWEB)

    Perez Jr, Joseph M; Bickford, Dennis F; Day, Delbert E; Kim, Dong-Sang; Lambert, Steven L; Marra, Sharon L; Peeler, David K; Strachan, Denis M; Triplett, Mark B; Vienna, John D; Wittman, Richard S

    2001-07-13

    At the Hanford Site in Richland, Washington, the path to site cleanup involves vitrification of the majority of the wastes that currently reside in large underground tanks. A Joule-heated glass melter is the equipment of choice for vitrifying the high-level fraction of these wastes. Even though this technology has general national and international acceptance, opportunities may exist to improve or change the technology to reduce the enormous cost of accomplishing the mission of site cleanup. Consequently, the U.S. Department of Energy requested the staff of the Tanks Focus Area to review immobilization technologies, waste forms, and modifications to requirements for solidification of the high-level waste fraction at Hanford to determine what aspects could affect cost reductions with reasonable long-term risk. The results of this study are summarized in this report.

  14. High-level radioactive wastes. Supplement 1

    Energy Technology Data Exchange (ETDEWEB)

    McLaren, L.H. (ed.)

    1984-09-01

    This bibliography contains information on high-level radioactive wastes included in the Department of Energy's Energy Data Base from August 1982 through December 1983. These citations are to research reports, journal articles, books, patents, theses, and conference papers from worldwide sources. Five indexes, each preceded by a brief description, are provided: Corporate Author, Personal Author, Subject, Contract Number, and Report Number. 1452 citations.

  15. High-level Synthesis Integrated Verification

    Directory of Open Access Journals (Sweden)

    M. Dossis

    2015-10-01

    Full Text Available It is widely known in the engineering community that more than 60% of the IC design project time is spent on verification. For the very complex contemporary chips, this may prove prohibitive for the IC to arrive at the correct time in the market and therefore, valuable sales share may be lost by the developing industry. This problem is deteriorated by the fact that most of conventional verification flows are highly repetitive and a great proportion of the project time is spent on last-moment simulations. In this paper we present an integrated approach to rapid, high-level verification, exploiting the advantages of a formal High-level Synthesis tool, developed by the author. Verification in this work is supported at 3 levels: high-level program code, RTL simulation and rapid, generated C testbench execution. This paper is supported by strong experimental work with 3-4 popular design synthesis and verification that proves the principles of our methodology.

  16. Spectroscopic properties of tellurite glasses co-doped with Er{sup 3+} and Yb{sup 3+}

    Energy Technology Data Exchange (ETDEWEB)

    Leal, J.J. [Instituto Politécnico Nacional CICATA-Unidad Altamira, Tamaulipas 89600 (Mexico); Narro-García, R., E-mail: roberto.narro@gmail.com [Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, A.P. 1-1010, Querétaro 76000, Querétaro México (Mexico); Desirena, H. [Centro de Investigaciones en Óptica, A.P. 1-948, León, Gto. 37150 (Mexico); Marconi, J.D. [Universidade Federal do ABC, SP (Brazil); Rodríguez, E. [Instituto Politécnico Nacional CICATA-Unidad Altamira, Tamaulipas 89600 (Mexico); Linganna, K. [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India); De la Rosa, E. [Centro de Investigaciones en Óptica, A.P. 1-948, León, Gto. 37150 (Mexico)

    2015-06-15

    Spectroscopic characterization of Er{sup 3+}/Yb{sup 3+} co-doped tellurite glasses 70.8TeO{sub 2}–5Al{sub 2}O{sub 3}–13K{sub 2}O–(11−x)–BaO–0.2Er{sub 2}O{sub 3}–xYb{sub 2}O{sub 3}, where x=0, 0.4, 0.8, 1.2 and 2 mol% has been carried out through X-ray diffraction, Raman, absorption and luminescence spectra. The Judd–Ofelt intensity parameters were calculated for 0.2 mol% Er{sup 3+}-doped glass and are used to evaluate radiative properties such as transition probabilities, branching ratios and radiative lifetime. The emission cross-section of the {sup 4}I{sub 13/2}→{sup 4}I{sub 15/2} transition has been calculated from the absorption data using McCumber's theory. The emission intensity of both, visible and infrared signals as a function of Yb{sub 2}O{sub 3}, have been studied under 980 nm and 375 nm laser excitation. The physical mechanisms responsible for both, visible and infrared signals in the tellurite samples have been explained in terms of the energy transfer and excited state absorption process. The FWHM of the {sup 4}I{sub 13/2}→{sup 4}I{sub 15/2} transition as a function of Yb{sub 2}O{sub 3} mol% and distance (δ) between the laser focusing point and the end-face of the glass has been reported. It was observed both, experimentally and numerically, a change in the FWHM with variations of δ less than 8 mm. The latter was attributed to the radiation trapping effect. - Highlights: • Er{sup 3+}/Yb{sup 3+} co-doped tellurite glasses were fabricated by the melt-quenching technique. • The structural, thermal and optical properties of the tellurite glasses were studied. • The radiation trapping effect has been observed in small tellurite glass samples. • Tellurite glasses could be a potential material for fiber fabrication.

  17. The CMS High-Level Trigger

    CERN Document Server

    Covarelli, Roberto

    2009-01-01

    At the startup of the LHC, the CMS data acquisition is expected to be able to sustain an event readout rate of up to 100 kHz from the Level-1 trigger. These events will be read into a large processor farm which will run the "High-Level Trigger" (HLT) selection algorithms and will output a rate of about 150 Hz for permanent data storage. In this report HLT performances are shown for selections based on muons, electrons, photons, jets, missing transverse energy, tau leptons and b quarks: expected efficiencies, background rates and CPU time consumption are reported as well as relaxation criteria foreseen for a LHC startup instantaneous luminosity.

  18. High-level waste qualification: Managing uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Pulsipher, B.A.

    1993-09-01

    A vitrification facility is being developed by the U.S. Department of Energy (DOE) at the West Valley Demonstration Plant (WVDP) near Buffalo, New York, where approximately 300 canisters of high-level nuclear waste glass will be produced. To assure that the produced waste form is acceptable, uncertainty must be managed. Statistical issues arise due to sampling, waste variations, processing uncertainties, and analytical variations. This paper presents elements of a strategy to characterize and manage the uncertainties associated with demonstrating that an acceptable waste form product is achieved. Specific examples are provided within the context of statistical work performed by Pacific Northwest Laboratory (PNL).

  19. Plasmon-Assisted Efficiency Enhancement of Eu3+-Doped Tellurite Glass-Covered Solar Cells

    Science.gov (United States)

    Lima, Bismarck C.; Gómez-Malagón, L. A.; Gomes, A. S. L.; Garcia, J. A. M.; Kassab, L. R. P.

    2017-12-01

    Rare-earth-doped tellurite glass containing metallic nanoparticles can be exploited to manage the solar spectrum in order to increase solar cell efficiency. It is therefore possible to modify the incident solar spectrum profile to the spectrum that optimizes the solar cell recombination process by covering the solar cell with plasmonic luminescent downshifting layers. With this approach, the losses due to thermalization are minimized and the efficiency is increased. Due to the down-conversion process that couples the plasmon resonance of the metallic nanoparticles and the rare-earth electronic energy levels, it is possible to convert photons from the ultraviolet region to the visible and near-band-gap region of the semiconductor. It is demonstrated here that plasmon-assisted efficiency enhancements of 14.0% and 34.5% can be obtained for commercial Si and GaP solar cells, respectively, covered with Eu3+-doped TeO2-ZnO glass containing silver nanoparticles.

  20. Assessment of lead tellurite glass for immobilizing electrochemical salt wastes from used nuclear fuel reprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Riley, Brian J.; Kroll, Jared O.; Peterson, Jacob A.; Pierce, David A.; Ebert, William L.; Williams, Benjamin D.; Snyder, Michelle M. V.; Frank, Steven M.; George, Jaime L.; Kruska, Karen

    2017-11-01

    This paper provides an overview of research evaluating the use of tellurite glass as a waste form for salt wastes from electrochemical processing. The capacities to immobilize different salts were evaluated including: a LiCl-Li2O oxide reduction salt (for oxide fuel) containing fission products, a LiCl-KCl eutectic salt (for metallic fuel) containing fission products, and SrCl2. Physical and chemical properties of the glasses were characterized by using X-ray diffraction, bulk density measurements, chemical durability tests, scanning electron microscopy, and energy dispersive X-ray emission spectroscopy. These glasses were found to accommodate high concentrations of halide salts and have high densities. However, improvements are needed to meet chemical durability requirements.

  1. Upconversion against direct emission in Er3+-Tm3+-codoped tellurite-glass containing gold nanoparticles

    Science.gov (United States)

    G. Rivera, V. A.; Silva, O. B.; El-Amraoui, M.; Ledemi, Y.; Messaddeq, Y.; Marega, E.

    2015-03-01

    Gold nanoparticle embedded in Er3+-Tm3+-codoped tellurite-glass are able produce two effects on the emission properties these glasses: (i) quenching on direct-emission under excitation by a 405 nm laser diode, or (ii) enhancement on upconversion-emission under excitation by a 976 nm laser diode in these glasses. Both effects were investigated from the luminescence decay dynamics of ions. The localized surface plasmon resonance band of gold nanoparticles at around 580 nm resulted in the quenching/enhancement of Er3+-Tm3+ emission for the Er3+:(4S3/2→4I15/2) transition. These hybrid materials can be utilized for various photonic applications, e.g. infrared to visible light converters or emitting green light.

  2. Thermal analysis and luminescence of phospho-tellurite glass doped with NdF3

    Science.gov (United States)

    Iwanowicz, Kamil; Dorosz, Dominik; Żmojda, Jacek; Kochanowicz, Marcin

    2015-09-01

    In the paper thermal and luminescence properties of phospho-tellurite glass and glass after thermal treatment doped with NdF3 were presented. The crystallization kinetic of the main crystallization peaks of glass was investigated using differential scanning calorimetry (DSC). The value of the activation energy for crystalline phase (Ec 54,21 +/- 5 kJ mol-1) was calculated using Ozawa-Flynn-Wall (OFW), Kissinger-Akahira-Sunose (KAS), Starink and Tang methods. The glass-ceramic was obtained by heat treatment method. The luminescence transitions from levels 4F5/2 --> 4I9/2 (878 nm), 4F3/2-->4I11/2 (1058 nm), and 4F3/2 --> 4I13/2 (1330 nm) in glass and glass-ceramic doped NdF3 were compered.

  3. Commissioning of the CMS High Level Trigger

    Energy Technology Data Exchange (ETDEWEB)

    Agostino, Lorenzo; et al.

    2009-08-01

    The CMS experiment will collect data from the proton-proton collisions delivered by the Large Hadron Collider (LHC) at a centre-of-mass energy up to 14 TeV. The CMS trigger system is designed to cope with unprecedented luminosities and LHC bunch-crossing rates up to 40 MHz. The unique CMS trigger architecture only employs two trigger levels. The Level-1 trigger is implemented using custom electronics, while the High Level Trigger (HLT) is based on software algorithms running on a large cluster of commercial processors, the Event Filter Farm. We present the major functionalities of the CMS High Level Trigger system as of the starting of LHC beams operations in September 2008. The validation of the HLT system in the online environment with Monte Carlo simulated data and its commissioning during cosmic rays data taking campaigns are discussed in detail. We conclude with the description of the HLT operations with the first circulating LHC beams before the incident occurred the 19th September 2008.

  4. Commissioning of the CMS High Level Trigger

    CERN Document Server

    Agostino, Lorenzo; Beccati, Barbara; Behrens, Ulf; Berryhil, Jeffrey; Biery, Kurt; Bose, Tulika; Brett, Angela; Branson, James; Cano, Eric; Cheung, Harry; Ciganek, Marek; Cittolin, Sergio; Coarasa, Jose Antonio; Dahmes, Bryan; Deldicque, Christian; Dusinberre, Elizabeth; Erhan, Samim; Gigi, Dominique; Glege, Frank; Gomez-Reino, Robert; Gutleber, Johannes; Hatton, Derek; Laurens, Jean-Francois; Loizides, Constantin; Ma, Frank; Meijers, Frans; Meschi, Emilio; Meyer, Andreas; Mommsen, Remigius K; Moser, Roland; O'Dell, Vivian; Oh, Alexander; Orsini, Luciano; Patras, Vaios; Paus, Christoph; Petrucci, Andrea; Pieri, Marco; Racz, Attila; Sakulin, Hannes; Sani, Matteo; Schieferdeckerd, Philipp; Schwick, Christoph; Serrano Margaleff, Josep Francesc; Shpakov, Dennis; Simon, Sean; Sumorok, Konstanty; Sungho Yoon, Andre; Wittich, Peter; Zanetti, Marco

    2009-01-01

    The CMS experiment will collect data from the proton-proton collisions delivered by the Large Hadron Collider (LHC) at a centre-of-mass energy up to 14 TeV. The CMS trigger system is designed to cope with unprecedented luminosities and LHC bunch-crossing rates up to 40 MHz. The unique CMS trigger architecture only employs two trigger levels. The Level-1 trigger is implemented using custom electronics, while the High Level Trigger (HLT) is based on software algorithms running on a large cluster of commercial processors, the Event Filter Farm. We present the major functionalities of the CMS High Level Trigger system as of the starting of LHC beams operations in September 2008. The validation of the HLT system in the online environment with Monte Carlo simulated data and its commissioning during cosmic rays data taking campaigns are discussed in detail. We conclude with the description of the HLT operations with the first circulating LHC beams before the incident occurred the 19th September 2008.

  5. Temperature-dependent fluorescence characteristics of an ytterbium-sensitized erbium-doped tellurite glass

    Energy Technology Data Exchange (ETDEWEB)

    Li Xujie [College of Computer Science and Engineering, Wenzhou University, Zhejiang 325035 (China); Faculty of Information Science and Engineering, State Key Laboratory, Base of Novel Functional Materials and Preparation Science, Ningbo University, Zhejiang 315211 (China)], E-mail: lixujie101@yahoo.com.cn; Zhang Wenjie [College of Computer Science and Engineering, Wenzhou University, Zhejiang 325035 (China)

    2008-09-01

    In this article, the 1.5 {mu}m emission spectra corresponding to the {sup 4}I{sub 13/2}{yields}{sup 4}I{sub 15/2} transition of Er{sup 3+} in tellurite glass are studied within the temperature from 8 to 300 K. The emission spectra of Er{sup 3+}: {sup 4}I{sub 13/2}{yields}{sup 4}I{sub 15/2} transition are also analyzed using a peak-fit routine, and an equivalent four-level system is proposed to estimate the stark splitting for the {sup 4}I{sub 15/2} and {sup 4}I{sub 13/2} levels of Er{sup 3+} in the tellurite glass. The results indicate that the {sup 4}I{sub 13/2}{yields}{sup 4}I{sub 15/2} emission of Er{sup 3+} can exhibit a considerable broadening due to a significant enhance the peak a', and b' change, respectively, and the peaks of which are located at about 1507 and 1556 nm. A detailed study of temperature-dependent 1.5 {mu}m emission spectra involving the change of the corresponding sub-bands shows that as the temperature decreases from 300 to 8 K, its line-shape becomes sharper and more intense (the full-width at half-maximum decreases from 59 to 38 nm). Temperature-dependent fluorescence intensities and the experimentally determined lifetimes are investigated; the results show that a decrease behavior of fluorescence intensities and lifetimes are observed for temperature from 8 to 300 K.

  6. Effect of Neodymium Nanoparticles on Elastic Properties of Zinc-Tellurite Glass System

    Directory of Open Access Journals (Sweden)

    Abdulbaset A. Abdulla Awshah

    2017-01-01

    Full Text Available The aim of this work is to determine the effect of neodymium nanoparticles concentration on the elastic properties of zinc-tellurite glass. A series of neodymium nanoparticles doped zinc-tellurite glass systems (NdNPsZT of composition [(TeO20.70(ZnO0.30]1-x(Nd2O3 NPs(x, x=0.01, 0.02, 0.03, 0.04, and 0.05, were synthesized by using conventional melt-quenching method. The amorphous nature of the glass system was confirmed by using XRD analysis. The density of the glass system was determined by Archimedes method. The elastic properties were calculated from the measured density and ultrasonic velocity at 5 MHz frequency. The experimental results showed that the elastic properties rely upon the composition of the glass systems and the impact of neodymium nanoparticles (Nd2O3 NPs within the glass network. The increase in ultrasonic velocities is due to the increase in rigidity and change in structural units of the glass system. The softening temperature and the microhardness increased with the increase in Nd3+ ions concentration from 0.1 to 0.2 mol and decreased when the Nd3+ ions concentration increased from 0.2 to 0.5 mol. Poisson’s ratio and Debye’s temperature decreased with the increase in the Nd3+ ions concentration from 0.1 to 0.2 mol and increased when the Nd3+ ions concentration was increased from 0.2 to 0.5 mol.

  7. Silver nanoparticles enhanced luminescence of Eu{sup 3+}-doped tellurite glass

    Energy Technology Data Exchange (ETDEWEB)

    Amjad, Raja J., E-mail: rajajunaid25@gmail.com [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Advanced Optical Material Research Group, Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Dousti, M.R. [Department of Physics, Tehran-North Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Sahar, M.R. [Advanced Optical Material Research Group, Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Shaukat, S.F. [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Ghoshal, S.K.; Sazali, E.S.; Nawaz, Fakhra [Advanced Optical Material Research Group, Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia)

    2014-10-15

    A series of silver nanoparticles (NPs) embedded zinc–tellurite glass is prepared by the melt-quench method. In order to nucleate and reduce the silver ions (Ag{sup +}) to silver NPs (Ag{sup 0}) heat treatment with different time intervals above the glass transition temperature is carried out. The transmission electron microscopy (TEM), differential thermal analyses (DTA), UV–vis-NIR absorption spectroscopy and photoluminescence (PL) spectroscopy are used to study the annealing time dependent optical properties. The glass transition temperature (T{sub g}) from DTA for an as prepared sample is 296 °C. TEM image displays the homogeneous distribution of silver NPs with average diameter ∼8 to 27 nm. From UV–vis-NIR spectra, the observed localized surface plasmon resonance (LSPR) bands are found to be located within the range 487–501 nm for the samples with AgCl. Furthermore, under an excitation of 395 nm, four bands are observed at 585, 612, 650, 698 nm which corresponds to the {sup 5}D{sub 0}-{sup 7}F{sub 0;1;2;3;4} transitions of Eu{sup 3+} ions. Moreover, luminescence intensity of all the bands is increased due to the presence of silver nanostructures. The hypersensitive transition {sup 5}D{sub 0}-{sup 7}F{sub 2} of Eu{sup 3+} is much more enhanced (∼1.9 times) mainly due to the local field effect of silver NPs. - Highlights: • A series of Eu{sup 3+} and silver NPs co-embedded zinc–tellurite glass is prepared. • TEM confirms the successful nucleation of silver NPs inside the glass host (d∼8 nm). • Luminescence is enhanced by annealing the sample upto 12 h. • Enhancement is attributed to the local field effect of silver NPs.

  8. Effect of AgCl on spectroscopic properties of erbium doped zinc tellurite glass

    Science.gov (United States)

    Reza Dousti, M.; Sahar, M. R.; Ghoshal, S. K.; Amjad, Raja J.; Samavati, A. R.

    2013-03-01

    The Er3+ doped zinc tellurite glass containing Ag nanoparticles (NPs) were synthesized from high purity raw materials by melt quenching method and the influence of Ag NPs on the spectroscopic properties were investigated. The glasses are characterized using DTA, EDX, TEM, FTIR, UV-Vis-NIR and photoluminescence (PL) techniques. The DTA data reveal that the addition of silver chloride increased the thermal stability from 0.52 to 0.67 for samples without and with 2 mol% AgCl respectively. The sharp peaks in EDX spectra show the presence of Ag nanocrystallites. The TEM micrograph shows the distribution of NPs is Gaussian and the average size is estimated ˜10 nm. Seven absorption bands of erbium were evidenced in the UV-Vis-NIR measurements. Optical band gap and density were found to decrease with addition of AgCl concentration, while molar volume increased. The PL spectra exhibit four peaks corresponding to 2H11/2 → 4I15/2, 4S3/2 → 4I15/2, 4F9/2 → 4I15/2 and 4S3/2 → 4I13/2 transitions. An enhancement in the order of six times for 2 mol% of dopant and a subsequent quench in luminescence spectra of co-doped zinc tellurite glasses were observed. Such enhancements were attributed to silver nanoparticles with average size of 10 nm and absorption band centered at 552 nm. The studied glasses provide enormous scope to achieve the materials suitable for nanophotonics, solid state lasers and color displays.

  9. Processing and characterization of core-clad tellurite glass preforms and fibers fabricated by rotational casting

    Science.gov (United States)

    Massera, J.; Haldeman, A.; Milanese, D.; Gebavi, H.; Ferraris, M.; Foy, P.; Hawkins, W.; Ballato, J.; Stolen, R.; Petit, L.; Richardson, K.

    2010-03-01

    We report results on the processing and characterization of tellurite-based glass preforms (core and cladding bulk glasses) and fibers within the TeO 2-Bi 2O 3-ZnO glass system. The core-clad fiber has been drawn from a core-clad preform prepared via rotational casting. Using Cu as a tracer to assess interface quality between the core and clad layers, we show excellent cladding layer thickness uniformity across lengths of up to 40 mm in a 65 mm long perform. No measurable diffusion of Cu between the core and the clad has been observed, within the accuracy of measurement, indicating good stability and interface quality during casting of melted glass. Micro-Raman spectroscopy has been used to identify subtle post-draw structural modification induced in the preform following the fiber drawing. These changes have been attributed to modification to the bulk glass' thermal history upon drawing and small scale molecular orientation of chain units within the tellurite glass matrix produced during the fiber drawing process. The resulting fiber was found to have an index step of (0.009 ± 0.002) between the fiber core and clad composition at 632 nm and propagation losses of (3.2 ± 0.1) dB/m at 632 nm and (2.1 ± 0.1) dB/m at 1.5 μm. The primary source of loss in the near-IR (NIR) is associated with residual hydroxyl (OH -) groups in the bulk preform which remain in the glass fiber.

  10. Influence of Europium Ion on Structural, Mechanical and Luminescence Behavior of Tellurite Nanoglass

    Science.gov (United States)

    Sazali, E. S.; Sahar, M. R.; Ghoshal, S. K.

    2013-04-01

    Understanding the mechanism of enhanced luminescence of rare earth doped glasses in the presence of nanocrystallites and growth kineics is fundamentally important for optical devices. Tellurite nanoglasses of composition (80-x) TeO2 - 5 Na2O - 15 MgO - (x) Eu2O3, over the concentration region of 0 to 2.5 mol% are prepared using conventional melt-quenching technique. The nanocrystalline particles are obtained by heating the as-cast glass at temperature 15-20°C above the glass crystallization temperature (Tc). The sizes of nanocrystallites are estimated from the X-Ray Diffraction (XRD) pattern using the Scherrer equation having average diameter ~68.7 nm. SEM studies revealed the nanocrystal glass morphology associated with the existence of crystalline phase. The glass density is determined by Precisa Densitometer and the hardness by the Vickers micro-hardness method. The density of tellurite nano-glass is found to be in the range of 5.2413 to 5.4933 g cm-3 while the Vickers microhardness varies from 2.77 to 2.93 GPa depending on the dopant concentration. The photoluminescence (PL) spectra exhibits five peaks around 568 nm, 600 nm, 628 nm, 664 nm and 712 nm assigned to 5D0 → 7F0, 5D0 → 7F1, 5D0 → 7F2, 5D0 → 7F3 and 5D0 → 7F4 transitions respectively. Interestingly, the FWHM and the inverse quality factor of the heat-treated glass are found to decrease with increasing concentration of Eu3+ dopants. Our observation may contribute towards the development of solid state lasers.

  11. Octave-spanning spectrum of femtosecond Yb:fiber ring laser at 528 MHz repetition rate in microstructured tellurite fiber.

    Science.gov (United States)

    Wang, Guizhong; Jiang, Tongxiao; Li, Chen; Yang, Hongyu; Wang, Aimin; Zhang, Zhigang

    2013-02-25

    The octave-spanning spectrum was generated in a tellurite glass based microstructured fiber pumped by a 528 MHz repetition rate Yb:fiber ring laser without amplification. The laser achieved 40% output optical-to-optical efficiency with the output power of 410 mW. By adjusting the grating pair in the cavity, this oscillator can work at different cavity dispersion regimes with the shortest dechirped pulse width of 46 fs. The output pulses were then launched into a high-nonlinearity tellurite fiber, which has the zero-dispersion wavelength at ~1 μm. The high nonlinearity coefficient (1348 km⁻¹W⁻¹) and the matched zero-dispersion wavelength with pump laser enable the octave-spanning supercontinuum generated from 750 nm to 1700 nm with the coupled pulse energy above 10 pJ.

  12. Tm3+ and Tm(3+)-Ho3+ co-doped tungsten tellurite glass single mode fiber laser.

    Science.gov (United States)

    Li, Kefeng; Zhang, Guang; Wang, Xin; Hu, Lili; Kuan, Peiwen; Chen, Danping; Wang, Meng

    2012-04-23

    We investigated the ~2 μm spectroscopic and lasing performance of Tm(3+) and Tm(3+)-Ho(3+) co-doped tungsten tellurite glass single mode fibers with a commercial 800 nm laser diode. The double cladding single mode (SM) fibers were fabricated by using rod-in-tube method. The propagation loss of the fiber was ~2.5 dB/m at 1310 nm. The spectroscopic properties of the fibers were analyzed. A 494 mW laser operating at ~1.9 μm was achieved in a Tm(3+) doped 20 cm long fiber, the slope efficiency was 26%, and the laser beam quality factor M(2) was 1.09. A 35 mW ~2.1 μm laser output was also demonstrated in a 7 cm long of Tm(3+)-Ho(3+) co-doped tungsten tellurite SM fiber. © 2012 Optical Society of America

  13. Tracking at High Level Trigger in CMS

    CERN Document Server

    Tosi, Mia

    2014-01-01

    A reduction of several orders of magnitude of the event rate is needed to reach values compatible with detector readout, offline storage and analysis capability. The CMS experiment has been designed with a two-level trigger system: the Level-1 Trigger (L1T), implemented on custom-designed electronics, and the High Level Trigger (HLT), a streamlined version of the CMS offline reconstruction software running on a computer farm. A software trigger system requires a trade-off between the complexity of the algorithms, the sustainable output rate, and the selection efficiency. With the computing power available during the 2012 data taking the maximum reconstruction time at HLT was about 200 ms per event, at the nominal L1T rate of 100 kHz. Track reconstruction algorithms are widely used in the HLT, for the reconstruction of the physics objects as well as in the identification of b-jets and lepton iso...

  14. The ARES High-level Intermediate Representation

    Energy Technology Data Exchange (ETDEWEB)

    Moss, Nicholas David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-03

    The LLVM intermediate representation (IR) lacks semantic constructs for depicting common high-performance operations such as parallel and concurrent execution, communication and synchronization. Currently, representing such semantics in LLVM requires either extending the intermediate form (a signi cant undertaking) or the use of ad hoc indirect means such as encoding them as intrinsics and/or the use of metadata constructs. In this paper we discuss a work in progress to explore the design and implementation of a new compilation stage and associated high-level intermediate form that is placed between the abstract syntax tree and when it is lowered to LLVM's IR. This highlevel representation is a superset of LLVM IR and supports the direct representation of these common parallel computing constructs along with the infrastructure for supporting analysis and transformation passes on this representation.

  15. Intergenerational ethics of high level radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Kunihiko [Nagoya Univ., Graduate School of Engineering, Nagoya, Aichi (Japan); Nasu, Akiko; Maruyama, Yoshihiro [Shibaura Inst. of Tech., Tokyo (Japan)

    2003-03-01

    The validity of intergenerational ethics on the geological disposal of high level radioactive waste originating from nuclear power plants was studied. The result of the study on geological disposal technology showed that the current method of disposal can be judged to be scientifically reliable for several hundred years and the radioactivity level will be less than one tenth of the tolerable amount after 1,000 years or more. This implies that the consideration of intergenerational ethics of geological disposal is meaningless. Ethics developed in western society states that the consent of people in the future is necessary if the disposal has influence on them. Moreover, the ethics depends on generally accepted ideas in western society and preconceptions based on racism and sexism. The irrationality becomes clearer by comparing the dangers of the exhaustion of natural resources and pollution from harmful substances in a recycling society. (author)

  16. Solitonic supercontinuum of femtosecond mid-IR pulses in W-type index tellurite fibers with two zero dispersion wavelengths

    Directory of Open Access Journals (Sweden)

    S. Kedenburg

    2016-11-01

    Full Text Available We present a detailed experimental parameter study on mid-IR supercontinuum generation in W-type index tellurite fibers, which reveals how the core diameter, pump wavelength, fiber length, and pump power dramatically influence the spectral broadening. As pump source, we use femtosecond mid-IR pulses from a post-amplified optical parametric oscillator tunable between 1.7 μm and 4.1 μm at 43 MHz repetition rate. We are able to generate red-shifted dispersive waves up to a wavelength of 5.1 μm by pumping a tellurite fiber in the anomalous dispersion regime between its two zero dispersion wavelengths. Distinctive soliton dynamics can be identified as the main broadening mechanism resulting in a maximum spectral width of over 2000 nm with output powers of up to 160 mW. We experimentally demonstrated that efficient spectral broadening with considerably improved power proportion in the important first atmospheric transmission window between 3 and 5 μm can be achieved in robust W-type tellurite fibers pumped at long wavelengths by ultra-fast lasers.

  17. Thermal stability and 2.7 μm spectroscopic properties in Er3+ doped tellurite glasses

    Science.gov (United States)

    Tian, Ying; Li, Bingpeng; Chen, Rong; Xia, Jienan; Jing, Xufeng; Zhang, Junjie; Xu, Shiqing

    2016-10-01

    In present paper, the thermal stability and 2.7 μm spectroscopic properties in Er3+ doped tellurite glasses have been investigated by 980 nm laser diode pumping. Thermal analysis indicates that GeO2 modified tellurite glass has better thermal stability and anti-crystallization ability. Judd-Ofelt intensity parameters are calculated and discussed to examine the covalency characteristics based on absorption spectra. The 2.7 μm fluorescence is obtained and the lifetime can reach 124 ± 1 μs with the quantum efficiency of 61.5% in prepared samples. Moreover, higher effective emission bandwidth (136.67 nm), emission cross sections (12.75 × 10-21 cm2) and radiative transition probability (95.66s-1) at 2.7 μm are achieved. In addition, upconversion and near-infrared emission spectra are measured to elucidate energy transfer mechanism of Er3+. The results suggest that the present tellurite glass modified by GeO2 might have promising applications in mid-infrared fiber lasers.

  18. Tracking at High Level Trigger in CMS

    CERN Document Server

    Tosi, Mia

    2016-01-01

    The trigger systems of the LHC detectors play a crucial role in determining the physics capabili- ties of the experiments. A reduction of several orders of magnitude of the event rate is needed to reach values compatible with detector readout, offline storage and analysis capability. The CMS experiment has been designed with a two-level trigger system: the Level-1 Trigger (L1T), implemented on custom-designed electronics, and the High Level Trigger (HLT), a stream- lined version of the CMS offline reconstruction software running on a computer farm. A software trigger system requires a trade-off between the complexity of the algorithms, the sustainable out- put rate, and the selection efficiency. With the computing power available during the 2012 data taking the maximum reconstruction time at HLT was about 200 ms per event, at the nominal L1T rate of 100 kHz. Track reconstruction algorithms are widely used in the HLT, for the reconstruction of the physics objects as well as in the identification of b-jets and ...

  19. The ATLAS high level trigger steering

    Science.gov (United States)

    Berger, N.; Bold, T.; Eifert, T.; Fischer, G.; George, S.; Haller, J.; Hoecker, A.; Masik, J.; Nedden, M. Z.; Reale, V. P.; Risler, C.; Schiavi, C.; Stelzer, J.; Wu, X.

    2008-07-01

    The High Level Trigger (HLT) of the ATLAS experiment at the Large Hadron Collider receives events which pass the LVL1 trigger at ~75 kHz and has to reduce the rate to ~200 Hz while retaining the most interesting physics. It is a software trigger and performs the reduction in two stages: the LVL2 trigger and the Event Filter (EF). At the heart of the HLT is the Steering software. To minimise processing time and data transfers it implements the novel event selection strategies of seeded, step-wise reconstruction and early rejection. The HLT is seeded by regions of interest identified at LVL1. These and the static configuration determine which algorithms are run to reconstruct event data and test the validity of trigger signatures. The decision to reject the event or continue is based on the valid signatures, taking into account pre-scale and pass-through. After the EF, event classification tags are assigned for streaming purposes. Several new features for commissioning and operation have been added: comprehensive monitoring is now built in to the framework; for validation and debugging, reconstructed data can be written out; the steering is integrated with the new configuration (presented separately), and topological and global triggers have been added. This paper will present details of the final design and its implementation, the principles behind it, and the requirements and constraints it is subject to. The experience gained from technical runs with realistic trigger menus will be described.

  20. Tracking at High Level Trigger in CMS

    Science.gov (United States)

    Tosi, M.

    2016-04-01

    The trigger systems of the LHC detectors play a crucial role in determining the physics capabilities of experiments. A reduction of several orders of magnitude of the event rate is needed to reach values compatible with detector readout, offline storage and analysis capability. The CMS experiment has been designed with a two-level trigger system: the Level-1 Trigger (L1T), implemented on custom-designed electronics, and the High Level Trigger (HLT), a streamlined version of the CMS offline reconstruction software running on a computer farm. A software trigger system requires a trade-off between the complexity of the algorithms, the sustainable output rate, and the selection efficiency. With the computing power available during the 2012 data taking the maximum reconstruction time at HLT was about 200 ms per event, at the nominal L1T rate of 100 kHz. Track reconstruction algorithms are widely used in the HLT, for the reconstruction of the physics objects as well as in the identification of b-jets and lepton isolation. Reconstructed tracks are also used to distinguish the primary vertex, which identifies the hard interaction process, from the pileup ones. This task is particularly important in the LHC environment given the large number of interactions per bunch crossing: on average 25 in 2012, and expected to be around 40 in Run II. We will present the performance of HLT tracking algorithms, discussing its impact on CMS physics program, as well as new developments done towards the next data taking in 2015.

  1. The ATLAS High Level Trigger Steering

    CERN Document Server

    Berger, N; Eifert, T; Fischer, G; George, S; Haller, J; Höcker, A; Masik, J; Zur Nedden, M; Pérez-Réale, V; Risler, C; Schiavi, C; Stelzer, J; Wu, X; International Conference on Computing in High Energy and Nuclear Physics

    2008-01-01

    The High Level Trigger (HLT) of the ATLAS experiment at the Large Hadron Collider receives events which pass the LVL1 trigger at ~75 kHz and has to reduce the rate to ~200 Hz while retaining the most interesting physics. It is a software trigger and performs the reduction in two stages: the LVL2 trigger and the Event Filter (EF). At the heart of the HLT is the Steering software. To minimise processing time and data transfers it implements the novel event selection strategies of seeded, step-wise reconstruction and early rejection. The HLT is seeded by regions of interest identified at LVL1. These and the static configuration determine which algorithms are run to reconstruct event data and test the validity of trigger signatures. The decision to reject the event or continue is based on the valid signatures, taking into account pre-scale and pass-through. After the EF, event classification tags are assigned for streaming purposes. Several powerful new features for commissioning and operation have been added: co...

  2. Structural, thermal and optical absorption features of heavy metal oxides doped tellurite rich glasses

    Directory of Open Access Journals (Sweden)

    Kawa M. Kaky

    Full Text Available In order to improve tellurite glass stability to be applicable for optical fiber amplifier applications, glasses with the composition of (70 − xTeO2. (10ZnO. (10WO3. (5Na2O. (5TiO2. (xBi2O3 (x = 1, 2, 3, 4, and 5 mol% have been produced and characterized using the related methods. Structural properties were investigated using X-ray diffraction (XRD which confirms the non-crystalline structure and scanning electron microscopy (SEM micrographs also confirm the XRD results. The energy dispersive X-ray (EDX analysis profiles show that all the mentioned elements are present in the prepared glasses. Following the IR spectra, all the tellurium bonds such as stretching vibrations of TeO4 tbp and TeO3/TeO3+1 unit are revealed. Raman spectra confirm the presence of different functional groups, actually, it shows bands mainly in four spectral regions: R1 (65–150 cm−1, R2 (280–550 cm−1, R3 (880–950 cm−1 and R4 (916–926 cm−1 and the identified bands are assigned to respective molecular groups. The thermal study was carried out using Differential scanning calorimetry (DSC which indicates good thermal stability of the synthesized glasses with increasing Bi concentration. From the optical absorption spectra, we evaluated cut-off edge wavelengths and found increasing cutoff wavelength with an increase in Bi2O3 concentration. In the UV–Visible region, optical band gap energy and allowed transitions were investigated using three methods; direct, indirect, and absorption spectrum fitting (ASF, and band gaps from indirect and ASF were matched. Keywords: Tellurite glasses, XRD, FT-IR, Raman, TGA/DSC

  3. Improved ionic conductivity of lithium-zinc-tellurite glass-ceramic electrolytes

    Directory of Open Access Journals (Sweden)

    W. Widanarto

    Full Text Available An enhancement in the secondary battery safety demands the optimum synthesis of glass-ceramics electrolytes with modified ionic conductivity. To achieve improved ionic conductivity and safer operation of the battery, we synthesized Li2O included zinc-tellurite glass-ceramics based electrolytes of chemical composition (85-xTeO2·xLi2O·15ZnO, where x = 0, 5, 10, 15 mol%. Samples were prepared using the melt quenching method at 800 °C followed by thermal annealing at 320 °C for 3 h and characterized. The effects of varying temperature, alternating current (AC frequency and Li2O concentration on the structure and ionic conductivity of such glass-ceramics were determined. The SEM images of the annealed glass-ceramic electrolytes displayed rough surface with a uniform distribution of nucleated crystal flakes with sizes less than 1 μm. X-ray diffraction analysis confirmed the well crystalline nature of achieved electrolytes. Incorporation of Li2O in the electrolytes was found to generate some new crystalline phases including hexagonal Li6(TeO6, monoclinic Zn2Te3O8 and monoclinic Li2Te2O5. The estimated crystallite size of the electrolyte was ranged from ≈40 to 80 nm. AC impedance measurement revealed that the variation in the temperatures, Li2O contents, and high AC frequencies have a significant influence on the ionic conductivity of the electrolytes. Furthermore, electrolyte doped with 15 mol% of Li2O exhibited the optimum performance with an ionic conductivity ≈2.4 × 10−7 S cm−1 at the frequency of 54 Hz and in the temperature range of 323–473 K. This enhancement in the conductivity was attributed to the sizable alteration in the ions vibration and ruptures of covalent bonds in the electrolytes network structures. Keywords: Zinc-tellurite, Glass-ceramics, X-ray diffraction, Ionic conductivity, Lithium oxide

  4. Formation of Se(0), Te(0), and Se(0)-Te(0) nanostructures during simultaneous bioreduction of selenite and tellurite in a UASB reactor.

    Science.gov (United States)

    Wadgaonkar, Shrutika L; Mal, Joyabrata; Nancharaiah, Yarlagadda V; Maheshwari, Neeraj O; Esposito, Giovanni; Lens, Piet N L

    2018-02-04

    Simultaneous removal of selenite and tellurite from synthetic wastewater was achieved through microbial reduction in a lab-scale upflow anaerobic sludge blanket reactor operated with 12 h hydraulic retention time at 30 °C and pH 7 for 120 days. Lactate was supplied as electron donor at an organic loading rate of 528 or 880 mg COD L-1 day-1. The reactor was initially fed with a synthetic influent containing 0.05 mM selenite and tellurite each (phase I, day 1-60) and subsequently with 0.1 mM selenite and tellurite each (phase II, day 61-120). At the end of phase I, selenite and tellurite removal efficiencies were 93 and 96%, respectively. The removal percentage dropped to 87 and 81% for selenite and tellurite, respectively, at the beginning of phase II because of the increased influent concentrations. The removal efficiencies of both selenite and tellurite were gradually restored within 20 days and stabilized at ≥ 97% towards the end of the experiment. Powder X-ray diffraction and Raman spectroscopy confirmed the formation of biogenic Se(0), Te(0), and Se(0)-Te(0) nanostructures. Scanning transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy showed aggregates comprising of Se(0), Te(0), and Se-Te nanostructures embedded in a layer of extracellular polymeric substances (EPS). Infrared spectroscopy confirmed the presence of chemical signatures of the EPS which capped the nanoparticle aggregates that had been formed and immobilized in the granular sludge. This study suggests a model for technologies for remediation of effluents containing Se and Te oxyanions coupled with biorecovery of bimetal(loid) nanostructures.

  5. YCu(TeO32(NO3(H2O3: a novel layered tellurite

    Directory of Open Access Journals (Sweden)

    Stuart J. Mills

    2016-08-01

    Full Text Available A new hydrated yttrium copper tellurite nitrate, yttrium(III copper(II bis[trioxidotellurate(IV] nitrate trihydrate, has been synthesized hydrothermally in a Teflon-lined autoclave and structurally determined using synchrotron radiation. The new phase is the first example containing yttrium, copper and tellurium in one structure. Its crystal structure is unique, with relatively strongly bound layers extending parallel to (020, defined by YO8, CuO4 and TeO3 polyhedra, while the NO3− anions and one third of the water molecules lie between those layers. The structural unit consists of [Cu2(TeO34]4− loop-branched chains of {Cu...Te...Cu...Te} squares running parallel to [001], which are linked further into layers only through Y(O,H2O8 polyhedra. Weak `secondary' Te bonds and O—H...O hydrogen-bonding interactions, involving water molecules and layer O atoms, link the layers and interlayer species. IR spectroscopic data are also presented.

  6. Composition and temperature-induced structural changes in lead-tellurite glasses on different length scales.

    Science.gov (United States)

    Chakraborty, S; Arora, A K; Sivasubramanian, V; Krishna, P S R; Krishnan, R Venkata

    2012-12-19

    Processes occurring at macroscopic and microscopic length scales across the glass transition (T(g)) in lead-tellurite glass (PbO)(x)(TeO(2))(1-x) (x = 0.1-0.3) are investigated using Brillouin and Raman spectroscopy, respectively. For all the samples, the temperature dependence of the longitudinal acoustic (LA) mode is found to exhibit a universal scaling below T(g) and a rapid softening above T(g). The lower value of elastic modulus at a higher concentration of network modifier PbO, estimated from Brillouin data, arises due to loss of network rigidity. From quantitative analysis of the reduced Raman spectra, several modes are found to exhibit anomalous changes across T(g). Instead of the expected anharmonic behaviour, several modes exhibit hardening, suggesting stiffening of the stretching force constants with temperature, the effect being more pronounced in glasses with higher x. In addition, incorporation of PbO in the glass is also found to narrow down the bond-length distribution, as evident from the sharpening of the Raman bands. The stiffening of the force constants of molecular units at a microscopic length scale and the decrease of elastic constant attributed to loss of network rigidity on a macroscopic length scale appear to be opposite. These different behaviours at two length scales are understood on the basis of a microscopic model involving TeO(n) and PbO units in the structure.

  7. A highly non-linear tellurite microstructure fiber with multi-ring holes for supercontinuum generation.

    Science.gov (United States)

    Liao, Meisong; Yan, Xin; Qin, Guanshi; Chaudhari, Chitrarekha; Suzuki, Takenobu; Ohishi, Yasutake

    2009-08-31

    We have fabricated a highly nonlinear complex microstructure tellurite fiber with a 1.8 micron core surrounded by four rings of holes. The cane for the fiber was prepared by combining the methods of cast rod in tube and stacking. In the process of fiber-drawing a positive pressure was pumped into the holes of cane to overcome the collapse of holes and reshape the microstructure. The correlations among pump pressure, hole size, surface tension and temperature gradient were investigated. The temperature gradient at the bottom of the preform's neck region was evaluated quantitatively by an indirect method. The chromatic dispersion of this fiber was compared with that of a step-index air-clad fiber. It was found that this fiber has a much more flattened chromatic dispersion. To the best of our knowledge this is the first report about a soft glass microstructure fiber which has such a small core together with four rings of holes for the dispersion engineering. The SC generation from this fiber was investigated under the pump of a 1557 nm femtosecond fiber laser. Infrared supercontinuum generation, free of fine structure, together with visible third harmonic generation was obtained under the pump of a femtosecond fiber laser with a pulse energy of several hundred pJ.

  8. Synthesis and different optical properties of Gd2O3 doped sodium zinc tellurite glasses

    Science.gov (United States)

    Samanta, Buddhadev; Dutta, Dibakar; Ghosh, Subhankar

    2017-06-01

    A series of Gd2O3 doped sodium zinc tellurite [xGd2O3-(0.8-x) TeO2-0.1Na2O-0.1ZnO] glasses are prepared by the conventional melt quenching method and their optical properties have been studied. UV-vis spectrophotometric studies within the wavelength range from 230 nm-800 nm are carried out in the integrating sphere mode to study the effect of Gd2O3 doping on the optical band gap (Eg), refractive index (n), dielectric constant (εr) and susceptibility (χ). Other physical properties like molar volume, molar refraction, polarizability, metallization criterion, number density of rare-earth ions (N), polaron radius (rp), inter ionic distance (ri), molar cation polarizability (∑αi), number of oxide ions in chemical composition (NO2-), optical band gap based electronic oxide ion polarizability (αO2-) and optical basicity (Λ) of glass samples have been studied on the basis of UV-vis spectra and density profile of the different glasses.

  9. Spectroscopic studies of Dy3 + ion doped tellurite glasses for solid state lasers and white LEDs

    Science.gov (United States)

    Himamaheswara Rao, V.; Syam Prasad, P.; Mohan Babu, M.; Venkateswara Rao, P.; Satyanarayana, T.; Luís F., Santos; Veeraiah, N.

    2018-01-01

    Rare earth ion Dy3 +-doped tellurite glasses were synthesised in the system of (75-x)TeO2-15Sb2O3-10WO3-xDy2O3 (TSWD glasses). XRD and FTIR characterizations were used to find the crystalline and structural properties. The intensities of the electronic transitions and the ligand environment around the Dy3 + ion were determined using the Judd-Ofelt (J-O) theory on the absorption spectra of the glasses. The measured luminescence spectra exhibit intense emissions at 574 and 484 nm along with less intense emissions around 662 and 751 nm. Various radiative properties of the 4F9/2 excited level of Dy3 + ion were calculated for the glasses. Decay profiles were measured to find the life times and quantum efficiencies. Yellow to blue intensity ratio (Y/B), CIE chromaticity coordinates and correlated color temperature (CCT) values are calculated using the emission spectra to evaluate the emitted light. The obtained results suggest the utility of the glasses for potential yellow laser and white LED's applications.

  10. Nd3+-doped lanthanum lead boro-tellurite glass for lasing and amplification applications

    Science.gov (United States)

    Madhu, A.; Eraiah, B.; Manasa, P.; Srinatha, N.

    2018-01-01

    Nd3+-doped lanthanum lead boro-tellurite glass samples were prepared by conventional melt quenching method and their structural, thermal, fluorescence, and decay times of the glasses were investigated. Prepared glass samples exhibits amorphous nature and shows good thermal stability in the temperature range of 100-800 °C. Judd-Ofelt (JO) analysis was carried out and the intensity parameters (Ωλ = 2, 4, 6) also spontaneous radiative probability and stimulated-.emission cross-sections were estimated. The magnitude of Ωλ confirms the covalency nature. The near infrared emission spectra were measured by 808 nm excitation in which the emission intensity is found to be high at 1060 nm for the 4F3/2 → 4F11/2 transition. The stimulated cross section, effective band width and branching ratios are found to be 8.910 × 10-20 cm2, 21.57 nm and 53.72 % respectively, for 4F3/2 → 4F11/2 transition. The derived gain bandwidth, figure of merit, threshold and saturation intensity found to be comparable to some of the glass systems. Furthermore, the time decay rate found to decrease from 100 μs to 27 μs when the concentration increased from 0.1 to 3.0 mol% of Nd3+ ions and also all follow the single exponential behaviour which is attributed to the self quenching effect due to the cross-relaxation channels.

  11. Composition dependent spectroscopic properties of Er{sup 3+}-doped boro-tellurite glasses

    Energy Technology Data Exchange (ETDEWEB)

    Selvaraju, K.; Marimuthu, K. [Department of Physics, Gandhigram Rural University, Gandhigram-624 302 (India); Vijaya, N. [Department of Physics, Sri Venkateswara University, Tirupati-517502 (India); Lavin, V. [Department de Fisica Fundamental y Experimental, Electronica y Sistemas, Universidad de La Laguna, 38200 San Cristobal de La Laguna, Santa Cruz de Tenerife (Spain)

    2013-03-15

    A new series of Er{sup 3+}-doped boro-tellurite glasses have been prepared and their spectroscopic behavior were explored through absorption and luminescence measurements. The nature of the Er{sup 3+}-ligand bond in the host matrix were studied through bonding parameter studies using absorption spectra. Davis and Mott theory is used to determine the optical band gap energy for the direct and indirect allowed transitions of the title glasses. Optical band gap energy for the indirect allowed transitions are found to be in the range of 3.03-2.36 eV. The Judd-Ofelt intensity parameters {Omega}{sub {lambda}} ({lambda} = 2, 4, and 6) were determined from the absorption spectra and used to derive the radiative properties like stimulated emission cross-section and gain bandwidth for the emission transition {sup 4}I{sub 13/2} {yields} {sup 4}I{sub 15/2} of the Er{sup 3+} ions. The spectroscopic properties of the prepared glasses were studied as a function of TeO{sub 2} in the host matrix and discussed with reported literature. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Nano-silver enhanced luminescence of Eu3+-doped lead tellurite glass

    Science.gov (United States)

    Reza Dousti, M.; Sahar, M. R.; Rohani, M. S.; Samavati, Alireza; Mahraz, Zahra Ashur; Amjad, Raja J.; Awang, Asmahani; Arifin, R.

    2014-05-01

    Eu3+-doped lead sodium tellurite glasses containing silver nanoparticles (NPs) were synthesized by melt-quenching technique and annealed for different time intervals at above the glass transition temperature. The glasses were characterized by UV-Vis-IR absorption, photoluminescence spectroscopy and transmission electron microscope imaging. Four absorption peaks of Eu3+ ion were observed due to transitions from ground state to different excited states in 400-600 nm region. The surface plasmon resonance (SPR) peak of silver NPs was probed at 632 nm. Five emission lines were recorded at 568, 587, 614, 650 and 704 nm which were intensified in the order of ˜1.9 times for heat-treated samples containing silver NPs. The average size of NPs was estimated to be ˜10 nm. Different mechanisms for interaction of light with metal and luminescent ions are discussed. Such enhancements are attributed to the strong local electric field induced by SPR of silver NPs as the major factor, and energy transfer from surface of silver NP to Eu3+ ion. The glasses show promising properties for optical applications.

  13. C-di-GMP regulates Pseudomonas aeruginosa stress response to tellurite during both planktonic and biofilm modes of growth

    DEFF Research Database (Denmark)

    Chua, Song Lin; Sivakumar, Krishnakumar; Rybtke, Morten Levin

    2015-01-01

    tellurite (TeO3(2-)) exposure induced the intracellular content of the secondary messenger cyclic di-GMP (c-di-GMP) of Pseudomonas aeruginosa. Two diguanylate cyclases (DGCs), SadC and SiaD, were responsible for the increased intracellular content of c-di-GMP. Enhanced c-di-GMP levels by TeO3(2-) further...

  14. The tellurite highly nonlinear microstructured fibers for THG and SC generations

    Science.gov (United States)

    Liao, Meisong; Chaudhari, Chitrarekha; Qin, Guanshi; Yan, Xin; Suzuki, Takenobu; Ohishi, Yasutake

    2010-04-01

    Tellurite highly nonlinear microstructured fibers were fabricated by pumping a positive pressure of nitrogen gas into the holes of cane in the fiber drawing process. By adjusting the pump pressure to inflate the holes of the fiber, the microstructures were reshaped, and the chromatic dispersions were tailored. Two kinds of fiber were fabricated. One is an air-clad fiber with a 1 μm hexagonal core, which is the smallest core in this shape for the air-clad fiber. By changing the inflation pressure, the diameter ratio of holey region to core (DRHC) was changed in the range of 1-20. Fibers with DRHC of 3.5, 10, 20 were demonstrated. By increasing the DRHC, the zero dispersion wavelengths were shifted to the short wavelength and the confinement loss were decreased. Another is a complex microstructure fiber with a 1.8 μm core surrounded by four ring holes. The shape of the microstructure was reshaped so heavily by the inflation pressure that it is obviously different from the original shape in the cane. The correlations among pump pressure, hole size, surface tension and temperature gradient were investigated. The temperature gradient at the bottom of the preform's neck region was evaluated quantitatively. The chromatic dispersion of this fiber was compared with that of a step-index air-clad fiber. It was found that this fiber had a much more flattened chromatic dispersion. Supercontinuum generations were investigated by the pump of a 1557 nm femtosecond fiber laser. Intense third harmonic generations were obtained from the 1μm haxgonal core fiber. Broad and flattened spectrum was obtained from the complex microstructure fiber. This investigations show that, by using a positive pressure to reshape the microstructure and by controlling the fabrication conditions exactly, highly nonlinear soft glass fibers with desirable chromatic dispersion can be fabricated, and such fibers have interesting applications in highly nonlinear field such as THG and SC generation.

  15. Structural and optical properties of tellurite thin film glasses deposited by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Munoz-Martin, D.; Fernandez-Navarro, J.M. [Laser Processing Group, Instituto de Optica (CSIC), Serrano 121, 28006 Madrid (Spain); Gonzalo, J., E-mail: j.gonzalo@io.cfmac.csic.es [Laser Processing Group, Instituto de Optica (CSIC), Serrano 121, 28006 Madrid (Spain); Jose, G.; Jha, A. [Institute for Materials Research, University of Leeds, Clarendon Road, Leeds LS2 9JT (United Kingdom); Fierro, J.L.G. [Instituto de Catalisis y Petroleoquimica (CSIC), Marie Curie s/n, 28049 Cantoblanco (Spain); Domingo, C. [Instituto de Estructura de la Materia (CSIC), Serrano 121, 28006 Madrid (Spain); Garcia-Lopez, J. [Centro Nacional de Aceleradores, P. Tecnologico ' Cartuja 93' , 41092 Sevilla (Spain)

    2011-10-31

    Tellurite (TeO{sub 2}-TiO{sub 2}-Nb{sub 2}O{sub 5}) thin film glasses have been produced by pulsed laser deposition at room temperature at laser energy densities in the range of 0.8-1.5 J/cm{sup 2} and oxygen pressures in the range of 3-11 Pa. The oxygen concentration in the films increases with laser energy density to reach values very close to that of the bulk glass at 1.5 J/cm{sup 2}, while films prepared at 1.5 J/cm{sup 2} and pressures above 5 Pa show oxygen concentration in excess of 10% comparing to the glass. X-ray photoelectron spectroscopy shows the presence of elementary Te in films deposited at O{sub 2} pressures {<=} 5 Pa that is not detected at higher pressures, while analysis of Raman spectra of the samples suggests a progressive substitution of TeO{sub 3} trigonal pyramids by TeO{sub 4} trigonal bipyramids in the films when increasing their oxygen content. Spectroscopic ellipsometry analysis combined with Cauchy and effective medium modeling demonstrates the influence of these compositional and structural modifications on the optical response of the films. Since the oxygen content determines their optical response through the structural modifications induced in the films, those can be effectively controlled by tuning the deposition conditions, and films having large n (2.08) and reduced k (< 10{sup -4}) at 1.5 {mu}m have been produced using the optimum deposition conditions.

  16. Spectroscopic properties of Sm3+ doped sodium-tellurite glasses: Judd-Ofelt analysis

    Science.gov (United States)

    Mawlud, Saman Q.; Ameen, Mudhafar M.; Sahar, Md. Rahim; Mahraz, Zahra Ashur Said; Ahmed, Kasim F.

    2017-07-01

    Modifying the optical response of rare earth doped inorganic glasses for diverse optical applications is the current challenge in materials science and technology. We report the enhancement of the visible emissions of the Sm3+ ions doped sodium-tellurite (TNS) glasses. The impacts of varying Sm3+ ions concentration on the spectroscopic properties of such glass samples are evaluated. Synthesized glass samples are characterized via emission and absorption measurements. The UV-Vis-NIR absorption spectra revealed nine absorption peaks which are assigned to the transitions from the ground level (6H5/2) to 6P3/2, 4I11/2, 6F11/2, 6F9/2, 6F7/2, 6F5/2, 6F3/2, 6H15/2 and 6F1/2 excited energy levels of Sm3+ ions. Emission spectra of the prepared glass under 404 nm excitation wavelength consisted of four bands centered at 561 nm, 598 nm, 643 nm and 704 nm which are originated from 4G5/2→6HJ (J = 5/2, 7/2, 9/2 and 11/2) transitions. The experimental oscillator strengths, fexp are calculated from the area under absorption bands. Using Judd-Ofelt theory and fit process of least square, the phenomenological intensity parameters Ωλ (λ = 2, 4, 6) are obtained. In order to evaluate potential applications of Sm3+ ions in telluride glasses, the spectroscopic parameters: radiative transition probability AR, branching ratio BR, radiative life time τr and stimulated emission cross section σλ for each band are calculated. These glass compositions could be a potential candidate for lasers.

  17. Simple one-pot aqueous synthesis of CdHgTe nanocrystals using sodium tellurite as the Te source

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Zhitao [Institute for Advanced Interdisciplinary Research in Science and Technology, East China Normal University, Shanghai (China); Luo, Chunhua [National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics of the Chinese Academy of Sciences, Shanghai (China); Huang, Rong [Key Laboratory of Polar Materials and Devices, Ministry of Education, School of Information Science and Technology, East China Normal University, Shanghai (China); Wang, Yiting [Institute for Advanced Interdisciplinary Research in Science and Technology, East China Normal University, Shanghai (China); Peng, Hui, E-mail: hpeng@ee.ecnu.edu.cn [Key Laboratory of Polar Materials and Devices, Ministry of Education, School of Information Science and Technology, East China Normal University, Shanghai (China); State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University (China); Polymer Electronic Research Centre, The University of Auckland, Private Bag 92019, Auckland (New Zealand); Travas-sejdic, Jadranka [Polymer Electronic Research Centre, The University of Auckland, Private Bag 92019, Auckland (New Zealand)

    2014-09-15

    In this work, we systematically investigated the one-pot aqueous synthesis conditions of CdHgTe nanocrystals (NCs) using sodium tellurite (Na{sub 2}TeO{sub 3}) as the Te source, and found that the added content of Hg{sup 2+} and the initial pH value of reaction solutions significantly affected the photoluminescence quantum yield (PL QY) of alloyed CdHgTe NCs. When the concentration of Cd was 1.0 mmol L{sup −1}, the mole ratio of Cd/Te/Hg/MPA was 1:0.5:0.05:2.4, and the initial pH value of the reaction solution was about 8.78, the PL QY of as-prepared CdHgTe NCs was up to 45%. Characterization by HRTEM and XRD confirmed the crystalline nature of CdHgTe NCs. Compared to other synthetic approaches of CdHgTe NCs, our experimental results indicate that Na{sub 2}TeO{sub 3} could be an attractive alternative Te source to directly synthesize CdHgTe NCs in aqueous media. - Highlights: • A one-pot method was developed for the synthesis of highly luminescent CdHgTe nanocrystals (NCs). • Sodium tellurite was used as the Te source. • The quantum yield reached up to 45%. • The experimental conditions were optimized and the prepared CdHgTe NCs were characterized.

  18. Photoluminescence study of Sm{sup 3+}–Yb{sup 3+}co-doped tellurite glass embedding silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Reza Dousti, M., E-mail: mrdousti@ifsc.usp.br [Laboratório de Espectroscopia de Materiais Funcionais (LEMAF), Instituto de Fisica de São Carlos, Universidade de São Paulo, Av. Trabalhador So-carlense 400, São Carlos, SP 13566-590 (Brazil); Department of Physics, Tehran-North Branch, Islamic Azad University Tehran (Iran, Islamic Republic of); Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia); Amjad, R.J. [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia); Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Hosseinian S, R.; Salehi, M.; Sahar, M.R. [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia)

    2015-03-15

    We report on the upconversion emission of Sm{sup 3+} ions doped tellurite glass in the presence of Yb{sup 3+} ions and silver nanoparticles. The enhancement of infrared-to-visible upconversion emissions is achieved under 980 nm excitation wavelength and attributed to the high absorption cross section of Yb{sup 3+} ions and an efficient energy transfer to Sm{sup 3+} ions. Further enhancements are attributed to the plasmonic effect via metallic nanoparticles resulting in the large localized field around rare earth ions. However, under excitation at 406 nm, the addition of Yb{sup 3+} content and heat-treated silver nanoparticles quench the luminescence of Sm{sup 3+} ions likely due to quantum cutting and plasmonic diluent effects, respectively. - Highlights: • Sm{sup 3+} tellurite glasses co-doped with Yb{sup 3+} ions and tri-doped with Yb{sup 3+}:Ag NPs were prepared. • In first step, Yb{sup 3+} ions enhanced the upconversion emissions of Sm{sup 3+} doped samples. • In second step, Ag NPs further enhanced the upconversion emissions in tri-doped glasses. • Finally, the quench in luminescence under 406 nm excitation is observed and discussed.

  19. Practical Use of High-level Petri Net

    DEFF Research Database (Denmark)

    The aim of the workshop is to bring together researchers and practitioners with interests in the use of high-level nets and their tools for practical applications. A typical paper is expected to report on a case study where high-level Petri nets and their tools have been used in practice. We also...... welcome papers describing a tool, a methodology, or other developments that have proved successful to make high-level Petri nets more applicable in practice....

  20. Deep borehole disposal of high-level radioactive waste.

    Energy Technology Data Exchange (ETDEWEB)

    Stein, Joshua S.; Freeze, Geoffrey A.; Brady, Patrick Vane; Swift, Peter N.; Rechard, Robert Paul; Arnold, Bill Walter; Kanney, Joseph F.; Bauer, Stephen J.

    2009-07-01

    Preliminary evaluation of deep borehole disposal of high-level radioactive waste and spent nuclear fuel indicates the potential for excellent long-term safety performance at costs competitive with mined repositories. Significant fluid flow through basement rock is prevented, in part, by low permeabilities, poorly connected transport pathways, and overburden self-sealing. Deep fluids also resist vertical movement because they are density stratified. Thermal hydrologic calculations estimate the thermal pulse from emplaced waste to be small (less than 20 C at 10 meters from the borehole, for less than a few hundred years), and to result in maximum total vertical fluid movement of {approx}100 m. Reducing conditions will sharply limit solubilities of most dose-critical radionuclides at depth, and high ionic strengths of deep fluids will prevent colloidal transport. For the bounding analysis of this report, waste is envisioned to be emplaced as fuel assemblies stacked inside drill casing that are lowered, and emplaced using off-the-shelf oilfield and geothermal drilling techniques, into the lower 1-2 km portion of a vertical borehole {approx}45 cm in diameter and 3-5 km deep, followed by borehole sealing. Deep borehole disposal of radioactive waste in the United States would require modifications to the Nuclear Waste Policy Act and to applicable regulatory standards for long-term performance set by the US Environmental Protection Agency (40 CFR part 191) and US Nuclear Regulatory Commission (10 CFR part 60). The performance analysis described here is based on the assumption that long-term standards for deep borehole disposal would be identical in the key regards to those prescribed for existing repositories (40 CFR part 197 and 10 CFR part 63).

  1. 40 CFR 227.30 - High-level radioactive waste.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false High-level radioactive waste. 227.30...-level radioactive waste. High-level radioactive waste means the aqueous waste resulting from the operation of the first cycle solvent extraction system, or equivalent, and the concentrated waste from...

  2. Mycobacterium massiliense BRA100 strain recovered from postsurgical infections: resistance to high concentrations of glutaraldehyde and alternative solutions for high level disinfection Mycobacterium massiliense clone BRA100 associado a infecções pós-cirúrgicas: resistência a altas concentrações de glutaraldeído e produtos alternativos para desinfecção de alto nível

    Directory of Open Access Journals (Sweden)

    Nádia Suely de Oliveira Lorena

    2010-10-01

    Full Text Available PURPOSE: To evaluate the minimum inhibitory concentration (MIC of GTA against these microorganisms and alternative disinfectants for high-level disinfection (HLD. METHODS: Reference mycobacteria and clinical M. massiliense strains were included in this study. Active cultures were submitted to susceptibility qualitative tests with GTA dilutions (ranging from 1.5% to 8%, and commercial orthophthaldehyde (OPA and peracetic acid (PA - based solutions, during the period of exposure as recommended by National Agency of Sanitary Surveillance for HLD. RESULTS: All reference and M. massiliense non-BRA100 strains, recovered from sputum, were susceptible to any GTA concentration, OPA and PA solutions. M. massiliense BRA100 strains presented MIC of 8% GTA and were susceptible to OPA and PA. CONCLUSION: M. massiliense BRA100 strain is resistant to high GTA concentrations (up to 7%, which proves that this product is non-effective against specific rapidly growing mycobacteria and should be substituted by OPA or PA - based solutions for HLD.OBJETIVO: Avaliar a concentração mínima inibitória (CMI de GTA frente a M. massiliense e a susceptibilidade a produtos alternativos para desinfecção de alto nível (DAN. MÉTODOS: Cepas de M. massiliense de origem clínica e de referência foram incluídas no estudo. As culturas ativadas foram submetidas a testes qualitativos com diluições de GTA (de 1,5% a 8% e com soluções comerciais de ortoftaldeído (OPA ou ácido peracético (PA, utilizando os tempos de exposição recomendados pela Agência Nacional de Vigilância Sanitária para DAN. RESULTADOS: Todas as cepas de referência e M. massiliense não-BRA100, obtida de escarro, foram susceptíveis às concentrações de GTA, e soluções de OPA e PA. As cepas de M. massiliense BRA100 apresentaram CMI de 8% para GTA e foram susceptíveis a OPA e PA. CONCLUSÃO: M. massiliense BRA100 é resistente a altas concentrações de GTA (até 7%, o que demonstra que esse

  3. Evaluation of shielding parameters for heavy metal fluoride based tellurite-rich glasses for gamma ray shielding applications

    Science.gov (United States)

    Sayyed, M. I.; Lakshminarayana, G.; Kityk, I. V.; Mahdi, M. A.

    2017-10-01

    In this work, we have evaluated the γ-ray shielding parameters such as mass attenuation coefficient (μ/ρ), effective atomic number (Zeff), half value layer (HVL), mean free path (MFP) and exposure buildup factors (EBF) for heavy metal fluoride (PbF2) based tellurite-rich glasses. In addition, neutron total macroscopic cross sections (∑R) for these glasses were also calculated. The maximum value for μ/ρ, Zeff and ∑R was found for heavy metal (Bi2O3) oxide introduced glass. The results of the selected glasses have been compared, in terms of MFP with different glass systems. The shielding effectiveness of the selected glasses is found comparable or better than of common ones, which indicates that these glasses with suitable oxides could be developed for gamma ray shielding applications.

  4. In-Use Evaluation of Peracetic Acid for High-Level Disinfection of Endoscopes.

    Science.gov (United States)

    Chenjiao, Wu; Hongyan, Zhang; Qing, Gu; Xiaoqi, Zhong; Liying, Gu; Ying, Fang

    2016-01-01

    Many high-level disinfectants have been used for disinfection of endoscopes such as 2% glutaraldehyde (GA), 0.55% ortho-phthalaldehyde (OPA), and peracetic acid (PAA). Both GA and OPA are widely used in disinfection of endoscopes and have been previously discussed, but there is little research on the practical use of PAA as an endoscope disinfectant. An experimental model of a flexible gastrointestinal endoscope being contaminated with 9 strains of microorganism was designed. After the cleaning and disinfecting procedure was completed, we evaluated the biocidal activity (850 ppm PAA, 2% GA, and 0.55% OPA) on our flexible gastrointestinal endoscope model. We also evaluated sterilization effectiveness of PAA on other bacteria, including some antibiotic-resistant bacteria (methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus, and Clostridium difficile). The residual bacterial colony count number of the PAA-disinfected endoscope was significantly lower than that of the GA- and OPA-disinfected endoscopes. The biocidal effect and efficiency of the endoscope disinfection by PAA appeared to be better than either the GA- or OPA-disinfected endoscope. PAA has demonstrated a good sterilization effect on other bacterial species; of particular note are common antibiotic-resistant bacteria such as methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus, and Clostridium difficile. The results of this study demonstrate that PAA is a fast and effective high-level disinfectant for use in the reprocessing of flexible endoscopes.

  5. High-Level Multi-Threading in hProlog

    OpenAIRE

    Van Overveldt, Timon; Demoen, Bart

    2011-01-01

    A new high-level interface to multi-threading in Prolog, implemented in hProlog, is described. Modern CPUs often contain multiple cores and through high-level multi-threading a programmer can leverage this power without having to worry about low-level details. Two common types of high-level explicit parallelism are discussed: independent and-parallelism and competitive or-parallelism. A new type of explicit parallelism, pipeline parallelism, is proposed. This new type can be used in certain c...

  6. Reachability Trees for High-level Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt; Jensen, Arne M.; Jepsen, Leif Obel

    1986-01-01

    High-level Petri nets have been introduced as a powerful net type by which it is possible to handle rather complex systems in a succinct and manageable way. The success of high-level Petri nets is undebatable when we speak about description, but there is still much work to be done to establish...... the necessary analysis methods. In other papers it is shown how to generalize the concept of place- and transition invariants from place/transition nets to high-level Petri nets. Our present paper contributes to this with a generalization of reachability trees, which is one of the other important analysis...

  7. Intense Upconverted White Light Emission from Tm3+ - Er3+ - Yb3+ Doped Zinc Tungsten Tellurite Glasses

    Directory of Open Access Journals (Sweden)

    Gokhan BİLİR

    2017-08-01

    Full Text Available The different amount of rare earth ions doped zinc tungsten tellurite glasses with the compositions (70-x-y-zTeO2 – 20ZnO – 10WO3 – xEr2O3 – yTm2O3 – zYb2O3 (x = 0.3, 0.5; y = 0.3, 0.5; z = 3 have been synthesized using melt quenching technique. Blue, green, red and infrared luminescence via energy transfer and frequency upconversion mechanisms in Tm3+/Er3+/Yb3+ triply-doped zinc tungsten tellurite glasses were investigated under single 975 nm diode laser excitation. Intense blue (Tm3+: 1D2→3F4, 1G4→3H6; 477 nm, green (2H11/2, 4S3/2→4I15/2 ; 525 nm and 549 nm, red (Er3+: 4F9/2→4I15/2, Tm3+: 1G4→3F4; 659 nm and infrared (Tm3+: 1G4→3H5, 3H4→3H6 ; 807 nm emissions were observed simultaneously at room temperature. Intense white light emission from all samples was observed with CCT values higher than 6500 K and CRI values lower than 80. The CIE coordinates of the emitted white light were found to shift to yellowish-greenish region with increasing pumping power. The possible energy transfer and upconversion mechanisms are discussed and plausible explanations are made.

  8. Effect of AlF3 on the Density and Elastic Properties of Zinc Tellurite Glass Systems

    Directory of Open Access Journals (Sweden)

    Zainal Abidin Talib

    2012-08-01

    Full Text Available This paper presents the results of the physical and elastic properties of the ternary zinc oxyfluoro tellurite glass system. Systematic series of glasses (AlF3x(ZnOy(TeO2z with x = 0–19, y = 0–20 and z = 80, 85, 90 mol% were synthesized by the conventional rapid melt quenching technique. The composition dependence of the physical, mainly density and molar volume, and elastic properties is discussed in term of the AlF3 modifiers addition that are expected to produce quite substantial changes in their physical properties. The absence of any crystalline peaks in the X-ray diffraction (XRD patterns of the present glass samples indicates the amorphous nature. The addition of AlF3 lowered the values of the densities in ternary oxyfluorotellurite glass systems. The longitudinal and transverse ultrasonic waves propagated in each glass sample were measured using a MBS8020 ultrasonic data acquisition system. All the velocity data were taken at 5 MHz frequency and room temperature. The longitudinal modulus (L, shear modulus (G, Young’s modulus (E, bulk modulus (K and Poisson’s ratio ( are obtained from both velocities data and their respective density. Experimental data shows the density and elastic moduli of each AlF3-ZnO-TeO2 series are found strongly depend upon the glass composition. The addition of AlF3 modifiers into the zinc tellurite causes substantial changes in their density, molar volume as well as their elastic properties.

  9. Effect of AlF3 on the Density and Elastic Properties of Zinc Tellurite Glass Systems

    Science.gov (United States)

    Sidek, Haji Abdul Aziz; Rosmawati, Shaharuddin; Halimah, Mohamed Kamari; Matori, Khamirul Amin; Talib, Zainal Abidin

    2012-01-01

    This paper presents the results of the physical and elastic properties of the ternary zinc oxyfluoro tellurite glass system. Systematic series of glasses (AlF3)x(ZnO)y(TeO2)z with x = 0–19, y = 0–20 and z = 80, 85, 90 mol% were synthesized by the conventional rapid melt quenching technique. The composition dependence of the physical, mainly density and molar volume, and elastic properties is discussed in term of the AlF3 modifiers addition that are expected to produce quite substantial changes in their physical properties. The absence of any crystalline peaks in the X-ray diffraction (XRD) patterns of the present glass samples indicates the amorphous nature. The addition of AlF3 lowered the values of the densities in ternary oxyfluorotellurite glass systems. The longitudinal and transverse ultrasonic waves propagated in each glass sample were measured using a MBS8020 ultrasonic data acquisition system. All the velocity data were taken at 5 MHz frequency and room temperature. The longitudinal modulus (L), shear modulus (G), Young’s modulus (E), bulk modulus (K) and Poisson’s ratio (σ) are obtained from both velocities data and their respective density. Experimental data shows the density and elastic moduli of each AlF3-ZnO-TeO2 series are found strongly depend upon the glass composition. The addition of AlF3 modifiers into the zinc tellurite causes substantial changes in their density, molar volume as well as their elastic properties.

  10. Intense visible upconversion and energy transfer in Ho3+/Yb3+ codoped tellurite glasses for potential fiber laser

    Science.gov (United States)

    Peng, Shengxi; Wu, Libo; Wang, Bo; Yang, Fengjing; Qi, Yawei; Zhou, Yaxun

    2015-03-01

    New Ho3+/Yb3+ codoped tellurite glasses (TeO2-Bi2O3-ZnO-Na2O) prepared by melt-quenching technique were investigated to realize visible-band upconversion emissions applied for compact fiber lasers. The absorption spectra, upconversion emission spectra, differential scanning calorimetry (DSC) curves, X-ray diffraction (XRD) and Raman spectra were measured to characterize the spectroscopic properties of Ho3+, thermal stability and structural nature of glass hosts. Under the excitation of 980 nm laser diode (LD), the intense green (∼543 nm) and red (∼657 nm) upconversion emissions corresponding to 5F4(5S2) → 5I8 and 5F5 → 5I8 transitions of Ho3+ respectively are simultaneously observed. The power dependence study of upconversion intensities on excited pump power revealed that the Ho3+ population at 5F4(5S2) and 5F5 levels was originated from two-photon absorption process based on the energy transfer from Yb3+ to Ho3+. The energy transfer mechanism from Yb3+ to Ho3+ was investigated and relevant micro-parameters (energy transfer coefficient and critical radius) and phonon contribution ratio were presented. With the increase of Yb3+ doped concentration, both the green and red upconversion intensities enhanced greatly, meanwhile the thermal stability of glass hosts, characterized by the three characteristic temperatures, also got a slight improvement. Furthermore, the glass structure was briefly analyzed with the calculated Judd-Ofelt intensity parameters, the measured Raman spectra and XRD curves. The present results indicate that the new synthesized Ho3+/Yb3+ codoped tellurite glass with intense green and red upconversion emissions is a promising medium applied for the visible-band fiber lasers.

  11. The enhanced and broadband near-infrared emission in Pr3+/Nd3+ co-doped tellurite glass

    Science.gov (United States)

    Zhou, Zizhong; Zhou, Yaxun; Cheng, Pan; Zhou, Minghan; Su, Xiue; Li, Jun

    2017-11-01

    This paper reports an enhanced and broadband near-infrared fluorescence emission in the Pr3+/Nd3+ co-doped tellurite glass, which was prepared using melt-quenching technique. Under the excitation of 488 nm laser diode (LD), three near-infrared emission bands at around 0.9, 1.04 and 1.30 μm from 3P1,0 → 1G4, 1G4→3H4 and 1G4→3H5 radiative transitions respectively were observed in the Pr3+ single-doped glass, and the fluorescence intensities increased further with the introduction of Nd3+ ions, which is mainly attributed to the energy transfers from Nd3+ to Pr3+ emissions. Meanwhile, the spectral overlapping of Pr3+:1G4→3H4 and Nd3+:4F3/2 → 4I11/2 radiative transitions resulted in a broadband emission ranging from 1000 to 1100 nm, whose full-width at half-maximum (FWHM) reached about 66 nm. Additionally, the spectroscopic properties of Nd3+ and Pr3+ ions were analyzed using Judd-Ofelt theory and the thermal stability property of prepared glass was characterized by the differential scanning calorimeter (DSC) measurement, and larger than 134 °C for the difference ΔT(=Tx -Tg) was observed, which indicates its feasibility for later fiber drawing. The enhanced fluorescence and broadband emission indicate that Pr3+/Nd3+ co-doped tellurite glass can be applied in the near-infrared band tunable lasers and broadband optical amplifiers.

  12. The major vault protein is related to the toxic anion resistance protein (TelA) family.

    Science.gov (United States)

    Suprenant, Kathy A; Bloom, Nathan; Fang, Jianwen; Lushington, Gerald

    2007-03-01

    Vaults are barrel-shaped ribonucleoprotein particles that are abundant in certain tumors and multidrug resistant cancer cells. Prokaryotic relatives of the major vault protein, MVP, have not been identified. We used sequence analysis and molecular modeling to show that MVP and the toxic anion resistance protein, TelA of Rhodobacter sphaeroides strain 2.4.1, share a novel fold that consists of a three-stranded antiparallel beta-sheet. Because of this strong structural correspondence, we examined whether mammalian cell vaults respond to tellurite treatment. In the presence of the oxyanion tellurite, large vault aggregates, or vaultosomes, appear at the cell periphery in 15 min or less. Vaultosome formation is temperature-dependent, reversible, and occurs in normal human umbilical vein endothelial cells as well as transformed HeLa cervical cancer cells. Vaultosome formation is not restricted to tellurite and occurs in the presence of other toxic oxyanions (selenate, selinite, arsenate, arsenite, vanadate). In addition, vaultosomes form independently from other stress-induced ribonucleoprotein complexes, stress granules and aggresomes. Vaultosome formation is therefore a unique cellular response to an environmental toxin.

  13. High-Level Waste System Process Interface Description

    Energy Technology Data Exchange (ETDEWEB)

    d' Entremont, P.D.

    1999-01-14

    The High-Level Waste System is a set of six different processes interconnected by pipelines. These processes function as one large treatment plant that receives, stores, and treats high-level wastes from various generators at SRS and converts them into forms suitable for final disposal. The three major forms are borosilicate glass, which will be eventually disposed of in a Federal Repository, Saltstone to be buried on site, and treated water effluent that is released to the environment.

  14. Compositional dependence of up-conversion emission and optical transition in Yb3+-Ho3+ co-doped tellurite-phosphate glasses

    Science.gov (United States)

    Yang, Yanmin; Zhang, Wei; Guo, Shuqing; Yang, Zhiping

    2010-07-01

    Optical absorption and photoluminescence properties of Yb3+-Ho3+ co-doped tellurite-phosphate glasses have been investigated. Up-conversion emissions have been observed at 540nm (green) and 650nm (red) at room temperature. The effect of host composition on up-conversion luminescence has been studied by analyzing the phenomenological Judd-Ofelt parameters Ωλ (λ = 2,4,6) as well as radiative transition probability and emission cross sections of 5F4 (5S2) and 5F5 levels in these glasses samples. Obtained data indicated that the green transition rapidly decreased relative to the red transition with increasing phosphate concentration, which can be attributed to increasing population of 5F4 (5S2) and 5F5 levels due to increasing host phonon energy. So, the color of up-conversion emission can be modulated by changed host composition. The effect of Ho3+ concentration on up-conversion emission was also studied in Yb3+-Ho3+ co-doped tellurite glasses. The red transition rapidly decreased relative to the green transition with increasing Ho3+ concentration. We attributed it to the lower phonon energy of tellurite glass host.

  15. On observation of the downconversion mechanism in Er{sup 3+}/Yb{sup 3+} co-doped tellurite glass using thermal and optical parameters

    Energy Technology Data Exchange (ETDEWEB)

    Figueiredo, M.S.; Santos, F.A. [Universidade Federal da Grande Dourados, Faculdade de Ciências Exatas e Tecnologias, Dourados, MS (Brazil); Yukimitu, K.; Moraes, J.C.S. [Universidade Estadual Paulista, UNESP, Departamento de Física e Química, Av. Brasil, 56, 15385-000 Ilha Solteira, SP (Brazil); Nunes, L.A.O. [Instituto de Física de São Carlos, Universidade de São Paulo, CP 369, 13560-970 São Carlos, SP (Brazil); Andrade, L.H.C. [Grupo de Espectroscopia Óptica e Fototérmica, Universidade Estadual de Mato Grosso do Sul, Cidade Universitária de Dourados, CP 351, Dourados, MS (Brazil); Lima, S.M., E-mail: smlima@uems.br [Grupo de Espectroscopia Óptica e Fototérmica, Universidade Estadual de Mato Grosso do Sul, Cidade Universitária de Dourados, CP 351, Dourados, MS (Brazil)

    2015-01-15

    In this work we report the observed downconversion (DC) mechanism in Er{sup 3+}/Yb{sup 3+}-codoped tellurite glasses (in mol%, 80TeO{sub 2}–10Li{sub 2}O–10TiO{sub 2}). The samples were synthesized by the conventional melt-quenching method and then studied using optical spectroscopy and thermal lens spectroscopy (TLS). These characterizations enabled investigation of the radiative and nonradiative processes involved in energy transfer from erbium to ytterbium. The visible Er{sup 3+} fluorescence intensities decreased as a function of the Yb{sup 3+} concentration, and there was a corresponding increase in the ytterbium emission at around 980 nm. Simultaneously, there was a reduction in the heat-generated due nonradiative decays (∼21%) when ytterbium was added. This temperature change was measured by TLS measurements and the results corroborate with the indicated by spectroscopic interpretation. - Highlights: • Energy transfer from erbium to ytterbium in tellurite glass. • ∼56% of cross-relaxation efficiency from Er{sup 3+} to Yb{sup 3+}. • Downconversion effect in tellurite glasses. • Downconversion effect observation by thermal lens spectroscopy.

  16. The 1.53 μm spectroscopic properties of Er3+/Ce3+/Yb3+ tri-doped tellurite glasses containing silver nanoparticles

    Science.gov (United States)

    Huang, Bo; Zhou, Yaxun; Yang, Fengjing; Wu, Libo; Qi, Yawei; Li, Jun

    2016-01-01

    The metallic silver nanoparticles (NPs) was introduced into the Er3+/Ce3+/Yb3+ tri-doped tellurite glasses with composition TeO2-ZnO-La2O3 to improve the 1.53 μm band fluorescence. The UV/Vis/NIR absorption spectra, 1.53 μm band fluorescence spectra, fluorescence lifetimes, X-ray diffraction (XRD) curves, differential scanning calorimeter (DSC) curves and transmission electron microscopy (TEM) image of tri-doped tellurite glasses were measured, together with the Judd-Ofelt intensity parameters, emission cross-sections, absorption cross-sections and radiative quantum efficiencies were calculated to investigate the effects of silver NPs on the 1.53 μm band spectroscopic properties of Er3+ ions, structural nature and thermal stability of glass hosts. It is shown that Er3+/Ce3+/Yb3+ tri-doped tellurite glasses can emit intense 1.53 μm band fluorescence through the combined energy transfer (ET) processes from Yb3+ to Er3+ ions and Er3+ to Ce3+ ions under the 980 nm excitation. At the same time, the introduction of an appropriate amount of silver NPs can further improve the 1.53 μm band fluorescence owing to the enhanced local electric field effect induced by localized surface Plasmon resonance (LSPR) of silver NPs and the possible energy transfer from silver NPs to Er3+ ions, and an improvement by about 120% of fluorescence intensity is found in the studied Er3+/Ce3+/Yb3+ tri-doped tellurite glass containing 0.5 mol% amount of silver NPs with average diameter of ∼15 nm. The energy transfer mechanisms from Yb3+ to Er3+ ions and Er3+ to Ce3+ ions were also quantitatively investigated by calculating energy transfer microparameters and phonon contribution ratios. Furthermore, the thermal stability of glass host increases slightly with the introduction of silver NPs while the glass structure maintains the amorphous nature. The results indicate that the prepared Er3+/Ce3+/Yb3+ tri-doped tellurite glass with an appropriate amount of silver NPs is an excellent gain

  17. High Level Waste (HLW) Feed Process Control Strategy

    Energy Technology Data Exchange (ETDEWEB)

    STAEHR, T.W.

    2000-06-14

    The primary purpose of this document is to describe the overall process control strategy for monitoring and controlling the functions associated with the Phase 1B high-level waste feed delivery. This document provides the basis for process monitoring and control functions and requirements needed throughput the double-shell tank system during Phase 1 high-level waste feed delivery. This document is intended to be used by (1) the developers of the future Process Control Plan and (2) the developers of the monitoring and control system.

  18. Effects of Feeding High Level of Cowpea Husk on the ...

    African Journals Online (AJOL)

    This study was conducted at Usmanu Danfodiyo University, Sokoto, to find out the effect of feeding high levels of cowpea husk on the haematological parameters and Blood urea nitrogen of Uda lambs. Fifteen (15) weeks feeding trial (including three (3) weeks digestibility trial) was conducted using sixteen (16) growing Uda ...

  19. High-Level Overview of Data Needs for RE Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Anthony

    2016-12-22

    This presentation provides a high level overview of analysis topics and associated data needs. Types of renewable energy analysis are grouped into two buckets: First, analysis for renewable energy potential, and second, analysis for other goals. Data requirements are similar but and they build upon one another.

  20. High-Level waste process and product data annotated bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Stegen, G.E.

    1996-02-13

    The objective of this document is to provide information on available issued documents that will assist interested parties in finding available data on high-level waste and transuranic waste feed compositions, properties, behavior in candidate processing operations, and behavior on candidate product glasses made from those wastes. This initial compilation is only a partial list of available references.

  1. Site suitability criteria for solidified high level waste repositories

    Energy Technology Data Exchange (ETDEWEB)

    Heckman, R.A.; Holdsworth, T.; Towse, D.F.

    1979-03-07

    Activities devoted to development of regulations, criteria, and standards for storage of solidified high-level radioactive wastes are reported. The work is summarized in sections on site suitability regulations, risk calculations, geological models, aquifer models, human usage model, climatology model, and repository characteristics. Proposed additional analytical work is also summarized. (JRD)

  2. Murine erythrocytes contain high levels of lysophospholipase activity

    NARCIS (Netherlands)

    Kamp, J.A.F. op den; Roelofsen, B.; Sanderink, G.; Middelkoop, E.; Hamer, R.

    1984-01-01

    Murine erythrocytes were found to be unique in the high levels of lysophospholipase activity in the cytosol of these cells. The specific activity of the enzyme in the cytosol of the murine cells is 10-times higher than in the cytosol of rabbit erythrocytes and approximately three orders of magnitude

  3. High Level Trigger Performance Plots for ICHEP2016

    CERN Document Server

    CMS Collaboration

    2016-01-01

    The performance of the High Level Trigger (HLT) with the first data collected in 2016 is presented. Preliminary results are shown on the performance of tau objects, b-tagging, SUSY and Exotics multijet triggers. Simulation on jet reconstruction at the HLT is also shown.

  4. High-level lipase production by Aspergillus candidus URM 5611 ...

    African Journals Online (AJOL)

    The current study evaluated lipase production by Aspergillus candidus URM 5611 through solid state fermentation (SSF) by using almond bran licuri as a new substrate. The microorganism produced high levels of the enzyme (395.105 U gds-1), thus surpassing those previously reported in the literature. The variable ...

  5. False high level in total bilirubin estimation in nonicteric serum

    African Journals Online (AJOL)

    reagents in next three days. Repeated estimations by Roche reagents showed falsely very high level of total bilirubin. However, estimation by DiaSys and Randox reagents showed acceptable normal levels as per visual estimation. There was interference, most probably due to paraprotein in the estimation of total bilirubin ...

  6. Cloning, high-level expression, purification and characterization of a ...

    African Journals Online (AJOL)

    The staphylokinase (Sak) is emerging as an important thrombolytic agent for the treatment of patients suffering from cardiovascular disease. Hence in this study, we reported the cloning, high-level expression, purification and characterization of the Sak variant SakøC from Staphylococcus aureus QT08 in Escherichia coli ...

  7. High level expression of human basic fibroblast growth factor in ...

    African Journals Online (AJOL)

    USER

    2010-04-19

    Apr 19, 2010 ... High-level expression of recombinant human basic fibroblast growth factor in Escherichia coli presents research opportunities such as analysis ... The general agreement from the published data on heterologous gene ..... for protein expression (Casimiro et al., 1997; Gold et al.,. 1981; Hamdan et al., 2002; ...

  8. Analisis FTIR dan Minimum Loss pada Kaca Tellurite-Bismuth-Zinc-Plumbum untuk Aplikasi Fiber Optik Infrared

    Directory of Open Access Journals (Sweden)

    Wahyudi -

    2014-01-01

    Full Text Available Peneltian ini bertujuan menganalisis spektrum Fourier Transform Infra Red (FTIR dan menentukan minimum loss dari kaca Tellurite-Bismuth-Zinc-Plumbum (TBZP yang dipengaruhi oleh variasi (PbO. Kaca TBZP difabrikasi dengan teknik melt quenching dengan komposisi 55TeO2–2Bi2O3–[43-x]ZnO–xPbO (%mol dengan x=2, 3, 4, 5. Hasil uji spektrum Fourier Transform Infra Red (FTIR menunjukkan pita absorbsi terbesar berada pada panjang gelombang lebih dari 620nm. Absorbansi tersebut lebih diakibatkan oleh adanya transisi vibrasi pada daerah infrared. Minimum loss pada kaca TBZP diprediksikan secara teoritis melalui fitting data infrared edge dengan kurva Rayleigh scattering. Minimum loss kaca TBZP sebasar 2,94 dB/km hingga 2,35 dB/km pada λ=5534,2nm hingga 5821,2nm. Nilai minimum loss menurun seiring pertambahan konsentrasi ion Pb2+ dalam kaca TBZP. Sifat tersebut menjadikan kaca ini sebagai kandidat yang baik untuk aplikasi yang menggunakan gelombang infrared seperti fiber optik infrared. The aims of this research were to analyze the spectrum of Fourier Transform Infra Red (FTIR and determine the minimum loss of Tellurite-Bismuth-Zinc-Plumbum (TBZP based glass which affected by the variation of (PbO. The TBZP glass has been fabricated by melt quenching technique with composition 55TeO2–2Bi2O3–[43-x]ZnO–xPbO (mol% with x=2, 3, 4, 5. Fourier Transform Infra Red (FTIR spectra test results showed that the greatest absorption bands were at wavelengths over 620nm. Vibrational transition has the reason behind the absorbance in the infrared region. Minimum loss on glass TBZP theoretically was predicted by fitted data from the infrared edge and rayleigh scattering curve. The minimum loss of TBZP was of the range 2,94 dB/km to 2,35 dB/km at λ=5534,2nm to 5821,2nm. The minimum loss of TBZP glass decreases as the Pb2+ content in glass increases. This makes these glasses are good candidate for IR-application such as infrared optical fiber.

  9. Microwave energy attenuators on the basis of aluminum nitride with high level of microwave energy absorption

    Directory of Open Access Journals (Sweden)

    Chasnyk V. I.

    2014-08-01

    Full Text Available Results of experimental studies of aluminum nitride based composites with addition of silicon carbide and molybdenum having high microwave absorption are presented. The interconnection between high level of absorption and volume electrical resistance was observed: maximum absorption of 6.5±1,0 dB/mm corresponds to the electrical resistance of (4—5·105 Ohm·m. Level of absorption of 3.5±0,5 dB/mm is revealed for the dielectric material with electrical conductivity of 1012 Ohm·m. The patterns detected during the study allow to predict the minimum and maximum levels of absorption of microwave energy in the two-phase composites based on aluminum nitride with molybdenum or silicon carbide, based on the measured volume of electrical resistance.

  10. Visual high-level regions respond to high-level stimulus content in the absence of low-level confounds.

    Science.gov (United States)

    Schindler, Andreas; Bartels, Andreas

    2016-05-15

    High-level regions of the ventral stream exhibit strong category selectivity to stimuli such as faces, houses, or objects. However, recent studies suggest that at least part of this selectivity stems from low-level differences inherent to images of the different categories. For example, visual outdoor and indoor scenes as well as houses differ in spatial frequency, rectilinearity and obliqueness when compared to face or object images. Correspondingly, scene responsive para-hippocampal place area (PPA) showed strong preference to low-level properties of visual scenes also in the absence of high-level scene content. This raises the question whether all high-level responses in PPA, the fusiform face area (FFA), or the object-responsive lateral occipital compex (LOC) may actually be explained by systematic differences in low-level features. In the present study we contrasted two classes of simple stimuli consisting of ten rectangles each. While both were matched in visual low-level features only one class of rectangle arrangements gave rise to a percept compatible with a high-level 3D layout such as a scene or an object. We found that areas PPA, transverse occipital sulcus (TOS, also referred to as occipital place area, OPA), as well as FFA and LOC showed robust responses to the visual scene class compared to the low-level matched control. Our results suggest that visual category responsive regions are not purely driven by low-level visual features but also by the high-level perceptual stimulus interpretation. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Belle-II High Level Trigger at SuperKEKB

    Science.gov (United States)

    Lee, S.; Itoh, R.; Higuchi, T.; Nakao, M.; Suzuki, S. Y.; Won, E.

    2012-12-01

    A next generation B-factory experiment, Belle II, is now being constructed at KEK in Japan. The upgraded accelerator SuperKEKB is designed to have the maximum luminosity of 8 × 1035 cm-2s-1 that is a factor 40 higher than the current world record. As a consequence, the Belle II detector yields a data stream of the event size ~1 MB at a Level 1 rate of 30 kHz. The Belle II High Level Trigger (HLT) is designed to reduce the Level 1 rate to 1/5 by performing the real time full event reconstruction and by applying the physics level event selection as the software trigger. In this paper, the development of the high level trigger system for Belle II and its performance is discussed.

  12. Storage of High Level Nuclear Waste in Germany

    Directory of Open Access Journals (Sweden)

    Dietmar P. F. Möller

    2007-01-01

    Full Text Available Nuclear energy is very often used to generate electricity. But first the energy must be released from atoms what can be done in two ways: nuclear fusion and nuclear fission. Nuclear power plants use nuclear fission to produce electrical energy. The electrical energy generated in nuclear power plants does not produce polluting combustion gases but a renewable energy, an important fact that could play a key role helping to reduce global greenhouse gas emissions and tackling global warming especially as the electricity energy demand rises in the years ahead. This could be assumed as an ideal win-win situation, but the reverse site of the medal is that the production of high-level nuclear waste outweighs this advantage. Hence the paper attempt to highlight the possible state-of-art concepts for the safe and sustaining storage of high-level nuclear waste in Germany.

  13. QSPIN: A High Level Java API for Quantum Computing Experimentation

    Science.gov (United States)

    Barth, Tim

    2017-01-01

    QSPIN is a high level Java language API for experimentation in QC models used in the calculation of Ising spin glass ground states and related quadratic unconstrained binary optimization (QUBO) problems. The Java API is intended to facilitate research in advanced QC algorithms such as hybrid quantum-classical solvers, automatic selection of constraint and optimization parameters, and techniques for the correction and mitigation of model and solution errors. QSPIN includes high level solver objects tailored to the D-Wave quantum annealing architecture that implement hybrid quantum-classical algorithms [Booth et al.] for solving large problems on small quantum devices, elimination of variables via roof duality, and classical computing optimization methods such as GPU accelerated simulated annealing and tabu search for comparison. A test suite of documented NP-complete applications ranging from graph coloring, covering, and partitioning to integer programming and scheduling are provided to demonstrate current capabilities.

  14. RETENTION OF SULFATE IN HIGH LEVEL RADIOACTIVE WASTE GLASS

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K.

    2010-09-07

    High level radioactive wastes are being vitrified at the Savannah River Site for long term disposal. Many of the wastes contain sulfate at concentrations that can be difficult to retain in borosilicate glass. This study involves efforts to optimize the composition of a glass frit for combination with the waste to improve sulfate retention while meeting other process and product performance constraints. The fabrication and characterization of several series of simulated waste glasses are described. The experiments are detailed chronologically, to provide insight into part of the engineering studies used in developing frit compositions for an operating high level waste vitrification facility. The results lead to the recommendation of a specific frit composition and a concentration limit for sulfate in the glass for the next batch of sludge to be processed at Savannah River.

  15. High-level Component Interfaces for Collaborative Development: A Proposal

    Directory of Open Access Journals (Sweden)

    Thomas Marlowe

    2009-12-01

    Full Text Available Software development has rapidly moved toward collaborative development models where multiple partners collaborate in creating and evolving software intensive systems or components of sophisticated ubiquitous socio-technical-ecosystems. In this paper we extend the concept of software interface to a flexible high-level interface as means for accommodating change and localizing, controlling and managing the exchange of knowledge and functional, behavioral, quality, project and business related information between the partners and between the developed components.

  16. VHDL Specification Methodology from High-level Specification

    OpenAIRE

    Benmohammed, M.; S. Merniz

    2005-01-01

    Design complexity has been increasing exponentially this last decade. In order to cope with such an increase and to keep up designers' productivity, higher level specifications were required. Moreover new synthesis systems, starting with a high level specification, have been developed in order to automate and speed up processor design. This study presents a VHDL specification methodology aimed to extend structured design methodologies to the behavioral level. The goal is t...

  17. Reprogrammable Controller Design From High-Level Specification

    OpenAIRE

    Benmohammed, M.; M. Bourahla; S. Merniz

    2003-01-01

    Existing techniques in high-level synthesis mostly assume a simple controller architecture model in the form of a single FSM. However, in reality more complex controller architectures are often used. On the other hand, in the case of programmable processors, the controller architecture is largely defined by the available control-flow instructions in the instruction set. With the wider acceptance of behavioral synthesis, the application of these methods for the design of programmable contr...

  18. Mixing Processes in High-Level Waste Tanks - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, P.F.

    1999-05-24

    The mixing processes in large, complex enclosures using one-dimensional differential equations, with transport in free and wall jets is modeled using standard integral techniques. With this goal in mind, we have constructed a simple, computationally efficient numerical tool, the Berkeley Mechanistic Mixing Model, which can be used to predict the transient evolution of fuel and oxygen concentrations in DOE high-level waste tanks following loss of ventilation, and validate the model against a series of experiments.

  19. The epistemological chain in high-level adventure sports coaches

    OpenAIRE

    Collins, L.; Collins, D; Grecic, D.,

    2015-01-01

    This paper considers the personal epistemology of adventure sports coaches, the existence of the epistemological chain and its impact on professional judgment and decision-making. The epistemological chain’s role and operationalization in other fields is considered, offering clues to how it may manifest itself in the adventure sports coach context. High-level adventure sports coaches were interviewed and an interpretive phenomenological analysis approach was adopted for the interview transcri...

  20. Femoroacetabular impingement in former high-level youth soccer players.

    Science.gov (United States)

    Johnson, Adam C; Shaman, Mark A; Ryan, Thomas G

    2012-06-01

    Femoroacetabular impingement (FAI) can be a source of hip pain in young adults. Repetitive kicking associated with youth soccer may lead to morphologic changes of the proximal femur that predispose a person to the development of FAI. Young adults who participated in high-level soccer competition as youths are more likely to demonstrate radiographic changes consistent with FAI and to have increased alpha angles as compared with controls. Cross-sectional study; Level of evidence, 3. Pelvic radiographs (anteroposterior and frog-lateral) were obtained on 50 individuals who participated in high-level soccer during skeletal immaturity and 50 controls who did not participate in high-level soccer. There were 25 men and 25 women in each group. All subjects were between 18 and 30 years of age, had a body mass index of less than 30, and had not sought or received treatment for hip disorders. Radiographs were analyzed independently for the presence of FAI, and alpha angles were measured. Hips with alpha angles that measured greater than or equal to 55° were deemed to have cam deformity. Fifteen of the 25 male subjects had evidence of cam deformity, compared with 14 male controls. Nine of the 25 female subjects had evidence of cam deformity, compared with 8 female controls. Neither of these differences was statistically significant. There was a significantly higher prevalence of cam deformity in men as compared with women (29 vs 17, P = .016). Participation in high-level soccer during skeletal immaturity is not associated with a higher risk of development of cam deformity in the young adult years. There is a high prevalence of cam deformity in the young adult population. Males demonstrate a higher prevalence of cam deformity than do females.

  1. Handbook of high-level radioactive waste transportation

    Energy Technology Data Exchange (ETDEWEB)

    Sattler, L.R.

    1992-10-01

    The High-Level Radioactive Waste Transportation Handbook serves as a reference to which state officials and members of the general public may turn for information on radioactive waste transportation and on the federal government`s system for transporting this waste under the Civilian Radioactive Waste Management Program. The Handbook condenses and updates information contained in the Midwestern High-Level Radioactive Waste Transportation Primer. It is intended primarily to assist legislators who, in the future, may be called upon to enact legislation pertaining to the transportation of radioactive waste through their jurisdictions. The Handbook is divided into two sections. The first section places the federal government`s program for transporting radioactive waste in context. It provides background information on nuclear waste production in the United States and traces the emergence of federal policy for disposing of radioactive waste. The second section covers the history of radioactive waste transportation; summarizes major pieces of legislation pertaining to the transportation of radioactive waste; and provides an overview of the radioactive waste transportation program developed by the US Department of Energy (DOE). To supplement this information, a summary of pertinent federal and state legislation and a glossary of terms are included as appendices, as is a list of publications produced by the Midwestern Office of The Council of State Governments (CSG-MW) as part of the Midwestern High-Level Radioactive Waste Transportation Project.

  2. High-Level Development of Multiserver Online Games

    Directory of Open Access Journals (Sweden)

    Frank Glinka

    2008-01-01

    Full Text Available Multiplayer online games with support for high user numbers must provide mechanisms to support an increasing amount of players by using additional resources. This paper provides a comprehensive analysis of the practically proven multiserver distribution mechanisms, zoning, instancing, and replication, and the tasks for the game developer implied by them. We propose a novel, high-level development approach which integrates the three distribution mechanisms seamlessly in today's online games. As a possible base for this high-level approach, we describe the real-time framework (RTF middleware system which liberates the developer from low-level tasks and allows him to stay at high level of design abstraction. We explain how RTF supports the implementation of single-server online games and how RTF allows to incorporate the three multiserver distribution mechanisms during the development process. Finally, we describe briefly how RTF provides manageability and maintenance functionality for online games in a grid context with dynamic resource allocation scenarios.

  3. The microscopic interaction parameters for Er{sup 3+}/Ho{sup 3+} energy transfer in tellurite glasses

    Energy Technology Data Exchange (ETDEWEB)

    Li Xujie [College of Computer Science and Engineering, Wenzhou University Zhejiang 325035 (China); Faculty of Information Science and Engineering, State Key Laboratory Base of Novel Functional Materials and Preparation Science, Ningbo University Zhejiang 315211 (China)], E-mail: lixujie101@yahoo.com.cn; Zhang Wenjie [College of Computer Science and Engineering, Wenzhou University Zhejiang 325035 (China)

    2008-08-01

    We investigate the energy transfer between Er{sup 3+}/Ho{sup 3+} in tellurite glasses. The main channels of energy transfer between Er{sup 3+}/Ho{sup 3+} are analyzed in detail. The microscopic interaction parameters of resonant and non-resonant (phonon-assisted) energy transfer parameters via Er{sup 3+}{yields}Ho{sup 3+} are calculated. The result shows that the resonant energy transfers Er{sup 3+}({sup 2}H{sub 11/2}({sup 4}S{sub 3/2})){yields}Ho{sup 3+}({sup 5}F{sub 4}({sup 5}S{sub 2})) and Er{sup 3+}({sup 4}F{sub 9/2}){yields}Ho{sup 3+}({sup 5}F{sub 5}) are very efficient and non-resonant energy transfers Er{sup 3+}({sup 4}I{sub 13/2}){yields}Ho{sup 3+}({sup 5}I{sub 7}) and Er{sup 3+}({sup 4}I{sub 11/2}){yields}Ho{sup 3+}({sup 5}I{sub 6}), which are a phonon-assisted energy transfer process because of energy mismatch are also existed and cannot be neglected.

  4. High-Level Synthesis: Productivity, Performance, and Software Constraints

    Directory of Open Access Journals (Sweden)

    Yun Liang

    2012-01-01

    Full Text Available FPGAs are an attractive platform for applications with high computation demand and low energy consumption requirements. However, design effort for FPGA implementations remains high—often an order of magnitude larger than design effort using high-level languages. Instead of this time-consuming process, high-level synthesis (HLS tools generate hardware implementations from algorithm descriptions in languages such as C/C++ and SystemC. Such tools reduce design effort: high-level descriptions are more compact and less error prone. HLS tools promise hardware development abstracted from software designer knowledge of the implementation platform. In this paper, we present an unbiased study of the performance, usability and productivity of HLS using AutoPilot (a state-of-the-art HLS tool. In particular, we first evaluate AutoPilot using the popular embedded benchmark kernels. Then, to evaluate the suitability of HLS on real-world applications, we perform a case study of stereo matching, an active area of computer vision research that uses techniques also common for image denoising, image retrieval, feature matching, and face recognition. Based on our study, we provide insights on current limitations of mapping general-purpose software to hardware using HLS and some future directions for HLS tool development. We also offer several guidelines for hardware-friendly software design. For popular embedded benchmark kernels, the designs produced by HLS achieve 4X to 126X speedup over the software version. The stereo matching algorithms achieve between 3.5X and 67.9X speedup over software (but still less than manual RTL design with a fivefold reduction in design effort versus manual RTL design.

  5. High-level waste management technology program plan

    Energy Technology Data Exchange (ETDEWEB)

    Harmon, H.D.

    1995-01-01

    The purpose of this plan is to document the integrated technology program plan for the Savannah River Site (SRS) High-Level Waste (HLW) Management System. The mission of the SRS HLW System is to receive and store SRS high-level wastes in a see and environmentally sound, and to convert these wastes into forms suitable for final disposal. These final disposal forms are borosilicate glass to be sent to the Federal Repository, Saltstone grout to be disposed of on site, and treated waste water to be released to the environment via a permitted outfall. Thus, the technology development activities described herein are those activities required to enable successful accomplishment of this mission. The technology program is based on specific needs of the SRS HLW System and organized following the systems engineering level 3 functions. Technology needs for each level 3 function are listed as reference, enhancements, and alternatives. Finally, FY-95 funding, deliverables, and schedules are s in Chapter IV with details on the specific tasks that are funded in FY-95 provided in Appendix A. The information in this report represents the vision of activities as defined at the beginning of the fiscal year. Depending on emergent issues, funding changes, and other factors, programs and milestones may be adjusted during the fiscal year. The FY-95 SRS HLW technology program strongly emphasizes startup support for the Defense Waste Processing Facility and In-Tank Precipitation. Closure of technical issues associated with these operations has been given highest priority. Consequently, efforts on longer term enhancements and alternatives are receiving minimal funding. However, High-Level Waste Management is committed to participation in the national Radioactive Waste Tank Remediation Technology Focus Area. 4 refs., 5 figs., 9 tabs.

  6. Market Designs for High Levels of Variable Generation: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Milligan, M.; Holttinen, H.; Kiviluoma, J.; Orths, A.; Lynch, M.; Soder, L.

    2014-10-01

    Variable renewable generation is increasing in penetration in modern power systems, leading to higher variability in the supply and price of electricity as well as lower average spot prices. This raises new challenges, particularly in ensuring sufficient capacity and flexibility from conventional technologies. Because the fixed costs and lifetimes of electricity generation investments are significant, designing markets and regulations that ensure the efficient integration of renewable generation is a significant challenge. This papers reviews the state of play of market designs for high levels of variable generation in the United States and Europe and considers new developments in both regions.

  7. ATLAS High Level Trigger Infrastructure, ROI Collection and Event Building

    CERN Document Server

    Kordas, K; Baines, J T M; Beck, H P; Bee, C; Bogaerts, A; Bold, T; Bosman, M; Comune, G; Cranfield, R; Crone, G; Di Mattia, A; Dos Anjos, A; Ellis, Nick; Ertorer, E; Falciano, S; Ferrari, R; Ferrer, M L; Gadomski, S; Gameiro, S; Garitaonandia, H; George, S; Gesualdi-Mello, A; Gorini, B; Green, B; Haeberli, C; Haller, J; Hauser, R; Joos, M; Kieft, G; Klous, S; Kugel, A; Lankford, A; Liu, W; Maeno, T; Masik, J; Meessen, C; Misiejuk, A; Morettini, P; Müller, M; Nagasaka, Y; Negri, A; Padilla, C; Pasqualucci, E; Pauly, T; Perera, V J O; Petersen, J; Portes de Albuquerque, M; Schiavi, C; Schlereth, J L; Segura, E; Seixas, M; Spiwoks, R; Stamen, R; Strong, J; Sushkov, S; Tapprogge, S; Teixeira-Dias, P; Torres, R; Touchard, F; Tremblet, L; Ünel, G; Vandelli, W; Van Wasen, J; Vermeulen, J; Werner, P; Wheeler, S; Wickens, F; Wiedenmann, W; Wu, X; Yasu, Y; Yu, M; Zobernig, H

    2006-01-01

    We describe the base-line design and implementation of the Data Flow and High Level Trigger (HLT) part of the ATLAS Trigger and Data Acquisition (TDAQ) system. We then discuss improvements and generalization of the system design to allow the handling of events in parallel data streams and we present the possibility for event duplication, partial Event Building and data stripping. We then present tests on the deployment and integration of the TDAQ infrastructure and algorithms at the TDAQ â€?pre-series” cluster (~10% of full ATLAS TDAQ). Finally, we tackle two HLT performance issues.

  8. Corrosion and failure processes in high-level waste tanks

    Energy Technology Data Exchange (ETDEWEB)

    Mahidhara, R.K.; Elleman, T.S.; Murty, K.L. [North Carolina State Univ., Raleigh, NC (United States)

    1992-11-01

    A large amount of radioactive waste has been stored safely at the Savannah River and Hanford sites over the past 46 years. The aim of this report is to review the experimental corrosion studies at Savannah River and Hanford with the intention of identifying the types and rates of corrosion encountered and indicate how these data contribute to tank failure predictions. The compositions of the High-Level Wastes, mild steels used in the construction of the waste tanks and degradation-modes particularly stress corrosion cracking and pitting are discussed. Current concerns at the Hanford Site are highlighted.

  9. Extending Java for High-Level Web Service Construction

    DEFF Research Database (Denmark)

    Christensen, Aske Simon; Møller, Anders; Schwartzbach, Michael Ignatieff

    2003-01-01

    We incorporate innovations from the project into the Java language to provide high-level features for Web service programming. The resulting language, JWIG, contains an advanced session model and a flexible mechanism for dynamic construction of XML documents, in particular XHTML. To support program...... development we provide a suite of program analyses that at compile time verify for a given program that no runtime errors can occur while building documents or receiving form input, and that all documents being shown are valid according to the document type definition for XHTML 1.0.We compare JWIG...

  10. Deployment of the ATLAS High-Level Triggers

    CERN Document Server

    Anjos, A; Baines, J T M; Beck, H P; Bee, C P; Biglietti, M; Bogaerts, J A C; Bosman, M; Burckhart, Doris; Caprini, M; Caron, B; Casado, M P; Cataldi, G; Cavalli, D; Ciobotaru, M; Comune, G; Conde, P; Corso-Radu, A; Crone, G; Damazio, D; De Santo, A; Díaz-Gómez, M; Di Mattia, A; Dobson, M; Ellis, Nick; Emeliyanov, D; Epp, B; Falciano, S; Ferrari, R; Francis, D; Gadomski, S; Gameiro, S; Garitaonandia, H; George, S; Ghete, V; Goncalo, R; Gorini, B; Gruwé, M; Haeberli, C; Haller, J; Joos, M; Kabana, S; Kazarov, A; Khomich, A; Kilvington, G; Kirk, J; Kolos, S; Konstantinidis, N P; Kootz, A; Lankford, A; Lehmann, G; Lowe, A; Luminari, L; Maeno, T; Masik, J; Meirosu, C; Meessen, C; Mello, A G; Moore, R; Morettini, P; Negri, A; Nikitin, N; Nisati, A; Osuna, C; Padilla, C; Panikashvili, N; Parodi, F; Pasqualucci, E; Pérez-Réale, V; Petersen, J; Pinfold, J L; Pinto, P; Qian, Z; Resconi, S; Rosati, S; Sánchez, C; Santamarina-Rios, C; Scannicchio, D A; Schiavi, C; Segura, E; Seixas, J M; Sivoklokov, S Yu; Sloper, J; Sobreira, A; Soloviev, I; Soluk, R A; Stancu, S; Stefanidis, E; Sushkov, S; Sutton, M; Tapprogge, S; Tarem, S; Thomas, E; Touchard, F; Tremblet, L; Ünel, G; Usai, G; Vandelli, Wainer R; Venda-Pinto, B; Ventura, A; Vercesi, V; Wengler, T; Werner, P; Wheeler, S J; Wickens, F J; Wiedenmann, W; Wielers, M; Wiesmann, M; Yasu, Y; Zobernig, G; 14th IEEE - NPSS Real Time Conference 2005 Nuclear Plasma Sciences Society

    2005-01-01

    The ATLAS combined test beam in the second half of 2004 saw the first deployment of the ATLAS High-Level Triggers (HLT). The next steps are deployment on the pre-series farms in the experimental area during 2005, commissioning and cosmics tests in 2006 and collisions in 2007. This paper reviews the experience gained in the test beam, describes the current status and discusses the further enhancements to be made. We address issues related to the dataflow, selection algorithms, testing, software distribution, installation and improvements.

  11. Lead iron phosphate glass as a containment medium for disposal of high-level nuclear waste

    Science.gov (United States)

    Boatner, Lynn A.; Sales, Brian C.

    1989-01-01

    Lead-iron phosphate glasses containing a high level of Fe.sub.2 O.sub.3 for use as a storage medium for high-level radioactive nuclear waste. By combining lead-iron phosphate glass with various types of simulated high-level nuclear waste, a highly corrosion resistant, homogeneous, easily processed glass can be formed. For corroding solutions at 90.degree. C., with solution pH values in the range between 5 and 9, the corrosion rate of the lead-iron phosphate nuclear waste glass is at least 10.sup.2 to 10.sup.3 times lower than the corrosion rate of a comparable borosilicate nuclear waste glass. The presence of Fe.sub.2 O.sub.3 in forming the lead-iron phosphate glass is critical. Lead-iron phosphate nuclear waste glass can be prepared at temperatures as low as 800.degree. C., since they exhibit very low melt viscosities in the 800.degree. to 1050.degree. C. temperature range. These waste-loaded glasses do not readily devitrify at temperatures as high as 550.degree. C. and are not adversely affected by large doses of gamma radiation in H.sub.2 O at 135.degree. C. The lead-iron phosphate waste glasses can be prepared with minimal modification of the technology developed for processing borosilicate glass nuclear wasteforms.

  12. BEAM SCRAPING FOR LHC INJECTION: HIGH LEVEL APPLICATION DEVELOPMENT

    CERN Document Server

    LETNES, P A

    2008-01-01

    The Large Hadron Collider (LHC) at CERN (European Organization for Nuclear Research) will be the world's most powerful accelerator when it is commissioned during 2008. To operate the LHC, injection of very high intensity beams from the Super Proton Synchrotron (SPS) pre-accelerator is required. With intensities of more than 3 _ 1013 p=cycle, it is essential that there is virtually no beam halo present. Such particles can hit the LHC beam pipe, and may cause magnet quenches due to heating. Fast scrapers have been installed in the SPS to measure and remove any halo before the beam is extracted towards the LHC. Fast scrapers have been chosen because there is too little time available for beam cleaning with large collimators. The scraper hardware has been in place in the SPS ring for several years. A low level computer for controlling the scrapers is also in place. A high level control application was, however, not written at the time. The development of the missing high level control application is the subject o...

  13. Spent Fuel and High-Level Radioactive Waste Transportation Report

    Energy Technology Data Exchange (ETDEWEB)

    1992-03-01

    This publication is intended to provide its readers with an introduction to the issues surrounding the subject of transportation of spent nuclear fuel and high-level radioactive waste, especially as those issues impact the southern region of the United States. It was originally issued by SSEB in July 1987 as the Spent Nuclear Fuel and High-Level Radioactive Waste Transportation Primer, a document patterned on work performed by the Western Interstate Energy Board and designed as a ``comprehensive overview of the issues.`` This work differs from that earlier effort in that it is designed for the educated layman with little or no background in nuclear waste Issues. In addition. this document is not a comprehensive examination of nuclear waste issues but should instead serve as a general introduction to the subject. Owing to changes in the nuclear waste management system, program activities by the US Department of Energy and other federal agencies and developing technologies, much of this information is dated quickly. While this report uses the most recent data available, readers should keep in mind that some of the material is subject to rapid change. SSEB plans periodic updates in the future to account for changes in the program. Replacement pages will be supplied to all parties in receipt of this publication provided they remain on the SSEB mailing list.

  14. Executive functions in kindergarteners with high levels of disruptive behaviours.

    Science.gov (United States)

    Monette, Sébastien; Bigras, Marc; Guay, Marie-Claude

    2015-11-01

    Executive function (EF) deficits have yet to be demonstrated convincingly in children with disruptive behaviour disorders (DBD), as only a few studies have reported these. The presence of EF weaknesses in children with DBD has often been contested on account of the high comorbidity between DBD and attention-deficit/hyperactivity disorder (ADHD) and of methodological shortcomings regarding EF measures. Against this background, the link between EF and disruptive behaviours in kindergarteners was investigated using a carefully selected battery of EF measures. Three groups of kindergarteners were compared: (1) a group combining high levels of disruptive behaviours and ADHD symptoms (COMB); (2) a group presenting high levels of disruptive/aggressive behaviours and low levels of ADHD symptoms (AGG); and (3) a normative group (NOR). Children in the COMB and AGG groups presented weaker inhibition capacities compared with normative peers. Also, only the COMB group showed weaker working memory capacities compared with the NOR group. Results support the idea that preschool children with DBD have weaker inhibition capacities and that this weakness could be common to both ADHD and DBD. © 2015 The British Psychological Society.

  15. FLUIDIZED BED STEAM REFORMING ENABLING ORGANIC HIGH LEVEL WASTE DISPOSAL

    Energy Technology Data Exchange (ETDEWEB)

    Williams, M

    2008-05-09

    Waste streams planned for generation by the Global Nuclear Energy Partnership (GNEP) and existing radioactive High Level Waste (HLW) streams containing organic compounds such as the Tank 48H waste stream at Savannah River Site have completed simulant and radioactive testing, respectfully, by Savannah River National Laboratory (SRNL). GNEP waste streams will include up to 53 wt% organic compounds and nitrates up to 56 wt%. Decomposition of high nitrate streams requires reducing conditions, e.g. provided by organic additives such as sugar or coal, to reduce NOX in the off-gas to N2 to meet Clean Air Act (CAA) standards during processing. Thus, organics will be present during the waste form stabilization process regardless of the GNEP processes utilized and exists in some of the high level radioactive waste tanks at Savannah River Site and Hanford Tank Farms, e.g. organics in the feed or organics used for nitrate destruction. Waste streams containing high organic concentrations cannot be stabilized with the existing HLW Best Developed Available Technology (BDAT) which is HLW vitrification (HLVIT) unless the organics are removed by pretreatment. The alternative waste stabilization pretreatment process of Fluidized Bed Steam Reforming (FBSR) operates at moderate temperatures (650-750 C) compared to vitrification (1150-1300 C). The FBSR process has been demonstrated on GNEP simulated waste and radioactive waste containing high organics from Tank 48H to convert organics to CAA compliant gases, create no secondary liquid waste streams and create a stable mineral waste form.

  16. High-level power analysis and optimization techniques

    Science.gov (United States)

    Raghunathan, Anand

    1997-12-01

    This thesis combines two ubiquitous trends in the VLSI design world--the move towards designing at higher levels of design abstraction, and the increasing importance of power consumption as a design metric. Power estimation and optimization tools are becoming an increasingly important part of design flows, driven by a variety of requirements such as prolonging battery life in portable computing and communication devices, thermal considerations and system cooling and packaging costs, reliability issues (e.g. electromigration, ground bounce, and I-R drops in the power network), and environmental concerns. This thesis presents a suite of techniques to automatically perform power analysis and optimization for designs at the architecture or register-transfer, and behavior or algorithm levels of the design hierarchy. High-level synthesis refers to the process of synthesizing, from an abstract behavioral description, a register-transfer implementation that satisfies the desired constraints. High-level synthesis tools typically perform one or more of the following tasks: transformations, module selection, clock selection, scheduling, and resource allocation and assignment (also called resource sharing or hardware sharing). High-level synthesis techniques for minimizing the area, maximizing the performance, and enhancing the testability of the synthesized designs have been investigated. This thesis presents high-level synthesis techniques that minimize power consumption in the synthesized data paths. This thesis investigates the effects of resource sharing on the power consumption in the data path, provides techniques to efficiently estimate power consumption during resource sharing, and resource sharing algorithms to minimize power consumption. The RTL circuit that is obtained from the high-level synthesis process can be further optimized for power by applying power-reducing RTL transformations. This thesis presents macro-modeling and estimation techniques for switching

  17. Wide-Range Temperature Sensors with High-Level Pulse Train Output

    Science.gov (United States)

    Hammoud, Ahmad; Patterson, Richard L.

    2009-01-01

    Two types of temperature sensors have been developed for wide-range temperature applications. The two sensors measure temperature in the range of -190 to +200 C and utilize a thin-film platinum RTD (resistance temperature detector) as the temperature-sensing element. Other parts used in the fabrication of these sensors include NPO (negative-positive- zero) type ceramic capacitors for timing, thermally-stable film or wirewound resistors, and high-temperature circuit boards and solder. The first type of temperature sensor is a relaxation oscillator circuit using an SOI (silicon-on-insulator) operational amplifier as a comparator. The output is a pulse train with a period that is roughly proportional to the temperature being measured. The voltage level of the pulse train is high-level, for example 10 V. The high-level output makes the sensor less sensitive to noise or electromagnetic interference. The output can be read by a frequency or period meter and then converted into a temperature reading. The second type of temperature sensor is made up of various types of multivibrator circuits using an SOI type 555 timer and the passive components mentioned above. Three configurations have been developed that were based on the technique of charging and discharging a capacitor through a resistive element to create a train of pulses governed by the capacitor-resistor time constant. Both types of sensors, which operated successfully over the wide temperature range, have potential use in extreme temperature environments including jet engines and space exploration missions.

  18. Vitrification of high-level alumina nuclear waste

    Energy Technology Data Exchange (ETDEWEB)

    Brotzman, J.R.

    1979-01-01

    Borophosphate glass compositions have been developed for the vitrification of a high-alumina calcined defense waste. The effect of substituting SiO/sub 2/, P/sub 2/O/sub 5/ and CuO for B/sub 2/O/sub 3/ on the viscosity and leach resistance was measured. The effect of the alkali to borate ratio and the Li/sub 2/O:Na/sub 2/O ratio on the melt viscosity and leach resistance was also measured.

  19. Gold nanoparticles assisted surface enhanced Raman scattering and luminescence of Er{sup 3+} doped zinc–sodium tellurite glass

    Energy Technology Data Exchange (ETDEWEB)

    Ghoshal, S.K.; Awang, Asmahani, E-mail: asmahani_awang@yahoo.com; Sahar, M.R.; Arifin, R.

    2015-03-15

    Significant enhancements in Er{sup 3+} luminescence and Raman intensity mediated via surface plasmon resonance (SPR) of gold (Au) nanoparticles (NPs) embedded zinc–sodium tellurite glass are reported. The observed modifications in the physical and spectroscopic properties are ascribed to the alterations in the glass network. XRD pattern confirms the amorphous nature of prepared glass sample. UV–vis-NIR spectra reveal seven absorption bands. Surface plasmon band is evidenced around 626–630 nm. TEM images manifest the growth of non-spherical Au NPs with average diameter between ∼7.2 nm and 8.6 nm. The visible up-conversion (UC) emission for all samples under 779 nm excitation exhibits three bands centered at 503 nm (green), 546 (green) and 637 nm (red) ascribed to {sup 2}H{sub 11/2}→{sup 4}I{sub 15/2}, {sup 4}S{sub 3/2}→{sup 4}I{sub 15/2} and {sup 4}F{sub 9/2}→{sup 4}I{sub 15/2} transitions. Glass sample with 0.4 mol% Au displaying the highest luminescence intensity with enhancement factor of 3.85 and 3.56 for green bands, and 7.61 for the red band is ascribed to the NPs local field enhancement and energy transfer between rare earth (RE) ions and NPs. FTIR spectra show the vibration of ZnO{sub 4} bonds, Te-O bond in TeO{sub 3} (tp) and TeO{sub 4} (tbp) units and the hydroxyl groups. Raman spectra demonstrate the presence of Er-O and Zn-O bond, anti-symmetric vibrations of Te-O-Te bonds and stretching modes of non-bonded oxygen exists in TeO{sub 3} and TeO{sub 3+1} unit. The amplifications in Raman signals by a factor of 1.62, 1.58, 1.64, 1.68 and 1.69 corresponding to the peak centered at 262 cm{sup −1}, 382 cm{sup −1}, 521 cm{sup −1}, 670 cm{sup −1} and 725 cm{sup −1} are attributed to the contribution of a surface plasmon generating a strong, localized and secondary field. We assert that our glass compositions offer favorable potential to develop solid state lasers and other versatile nanophotonic devices. - Highlights: • Gold

  20. Kinetics of high-Level of ß-glucosidase production by a 2-deoxyglucose-resistant mutant of Humicola lanuginosa in submerged fermentation Cinética de produção de ß-glucosidase por um mutante de Hemicola lanuginosa resistente a 2-deoxiglucose em fermentação submersa

    Directory of Open Access Journals (Sweden)

    Syed Ali Imran Bokhari

    2008-12-01

    Full Text Available A 2-deoxyglucose-resistant mutant (M7 of Humicola lanuginosa was obtained by exposing conidia to γ-rays and permitting expression in broth containing 0.6% 2-deoxyglucose (DG and cellobiose (1% before plating on DG esculin-ferric ammonium citrate agar medium from which colonies showing faster and bigger blackening zones were selected. Kinetic parameters for enhanced ß-glucosidase (BGL synthesis by M7 were achieved when corncobs acted as the carbon source. The combination between corncobs and corn steep liquor was the best to support higher values of all product formation kinetic parameters. Effect of temperature on the kinetic and thermodynamic attributes of BGL production equilibrium in the wild organismand M7was studied using batch process at eight different temperatures in shake-flask studies. The best performance was found at 45ºC and 20 g L-1 corncobs in 64 h. Both growth and product formation (17.93 U mL-1 were remarkably high at 45ºC and both were coupled under optimum working conditions. Product yield of BGL from the mutant M7 (1556.5 U g-1 dry corncobs was significantly higher than the values reported on all fungal and bacterial systems. Mutation had thermo-stabilization influence on the organism and mutant required lower activation energy for growth and lower magnitudes of enthalpy and entropy for product formation than those demanded by the wild organism, other mesophilic and thermo-tolerant organisms. In the inactivation phase, the organisms needed lower values of activation energy, enthalpy and entropy for product formation equilibrium, confirming thermophilic nature of metabolic network possessed by the mutant organism.Um mutante de Hemicola lanuginosa resistente a 2-deoxiglucose(M7 foi obtido através de exposição de conídios a raios γ, permitindo a expressão em caldo contendo 0,6% de 2-deoxiglucose (DG e celobiose (1% antes da semeadura em ágar DG esculina citrato de ferro amoniacal, da qual foram selecionadas as col

  1. High Level Waste System Impacts from Acid Dissolution of Sludge

    Energy Technology Data Exchange (ETDEWEB)

    KETUSKY, EDWARD

    2006-04-20

    This research evaluates the ability of OLI{copyright} equilibrium based software to forecast Savannah River Site High Level Waste system impacts from oxalic acid dissolution of Tank 1-15 sludge heels. Without further laboratory and field testing, only the use of oxalic acid can be considered plausible to support sludge heel dissolution on multiple tanks. Using OLI{copyright} and available test results, a dissolution model is constructed and validated. Material and energy balances, coupled with the model, identify potential safety concerns. Overpressurization and overheating are shown to be unlikely. Corrosion induced hydrogen could, however, overwhelm the tank ventilation. While pH adjustment can restore the minimal hydrogen generation, resultant precipitates will notably increase the sludge volume. OLI{copyright} is used to develop a flowsheet such that additional sludge vitrification canisters and other negative system impacts are minimized. Sensitivity analyses are used to assess the processability impacts from variations in the sludge/quantities of acids.

  2. High-Level Language Production in Parkinson's Disease: A Review

    Directory of Open Access Journals (Sweden)

    Lori J. P. Altmann

    2011-01-01

    Full Text Available This paper discusses impairments of high-level, complex language production in Parkinson's disease (PD, defined as sentence and discourse production, and situates these impairments within the framework of current psycholinguistic theories of language production. The paper comprises three major sections, an overview of the effects of PD on the brain and cognition, a review of the literature on language production in PD, and a discussion of the stages of the language production process that are impaired in PD. Overall, the literature converges on a few common characteristics of language production in PD: reduced information content, impaired grammaticality, disrupted fluency, and reduced syntactic complexity. Many studies also document the strong impact of differences in cognitive ability on language production. Based on the data, PD affects all stages of language production including conceptualization and functional and positional processing. Furthermore, impairments at all stages appear to be exacerbated by impairments in cognitive abilities.

  3. The High Level Trigger of the CMS experiment

    CERN Document Server

    Gao, Xuyang

    2016-01-01

    The CMS experiment has been designed with a 2-level trigger system the Level 1 Trigger, implemented on custom-designed electronics, and the High Level Trigger, a streamlined version of the CMS offline reconstruction software running on a computer farm. In this poster we will present the performance with the specific algorithms developed to cope with the increasing LHC pile-up and bunch crossing rate using 13 TeV data during 2015, and prospects for improvements brought to both L1T and HLT strategies to meet the new challenges for 2016 scenarios with a peak instantaneous luminosity of $1.2 \\times 10^{34} $cm$^{-2}$s$^{-1}$ and 30 pileup events.

  4. SIMULANT DEVELOPMENT FOR SAVANNAH RIVER SITE HIGH LEVEL WASTE

    Energy Technology Data Exchange (ETDEWEB)

    Stone, M; Russell Eibling, R; David Koopman, D; Dan Lambert, D; Paul Burket, P

    2007-09-04

    The Defense Waste Processing Facility (DWPF) at the Savannah River Site vitrifies High Level Waste (HLW) for repository internment. The process consists of three major steps: waste pretreatment, vitrification, and canister decontamination/sealing. The HLW consists of insoluble metal hydroxides (primarily iron, aluminum, magnesium, manganese, and uranium) and soluble sodium salts (carbonate, hydroxide, nitrite, nitrate, and sulfate). The HLW is processed in large batches through DWPF; DWPF has recently completed processing Sludge Batch 3 (SB3) and is currently processing Sludge Batch 4 (SB4). The composition of metal species in SB4 is shown in Table 1 as a function of the ratio of a metal to iron. Simulants remove radioactive species and renormalize the remaining species. Supernate composition is shown in Table 2.

  5. Reprogrammable Controller Design From High-Level Specification

    Directory of Open Access Journals (Sweden)

    M. Benmohammed

    2003-10-01

    Full Text Available Existing techniques in high-level synthesis mostly assume a simple controller architecture model in the form of a single FSM. However, in reality more complex controller architectures are often used. On the other hand, in the case of programmable processors, the controller architecture is largely defined by the available control-flow instructions in the instruction set. With the wider acceptance of behavioral synthesis, the application of these methods for the design of programmable controllers is of fundamental importance in embedded system technology. This paper describes an important extension of an existing architectural synthesis system targeting the generation of ASIP reprogrammable architectures. The designer can then generate both style of architecture, hardwired and programmable, using the same synthesis system and can quickly evaluate the trade-offs of hardware decisions.

  6. Simulation Modeling of Space Missions Using the High Level Architecture

    Directory of Open Access Journals (Sweden)

    Luis Rabelo

    2013-01-01

    Full Text Available This paper discusses an environment being developed to model a mission of the Space Launch System (SLS and the Multipurpose Crew Vehicle (MPCV being launched from Kennedy Space Center (KSC to the International Space Station (ISS. Several models representing different phases of the mission such as the ground operations processes, engineered systems, and range components such as failure tree, blast, gas dispersion, and debris modeling are explained. These models are built using different simulation paradigms such as continuous, system dynamics, discrete-event, and agent-based simulation modeling. The High Level Architecture (HLA is the backbone of this distributed simulation. The different design decisions and the information fusion scheme of this unique environment are explained in detail for decision-making. This can also help in the development of exploration missions beyond the International Space Station.

  7. Transmutation of high-level radioactive waste - Perspectives

    CERN Document Server

    Junghans, Arnd; Grosse, Eckart; Hannaske, Roland; Kögler, Toni; Massarczyk, Ralf; Schwengner, Ronald; Wagner, Andreas

    2014-01-01

    In a fast neutron spectrum essentially all long-lived actinides (e.g. Plutonium) undergo fission and thus can be transmuted into generally short lived fission products. Innovative nuclear reactor concepts e.g. accelerator driven systems (ADS) are currently in development that foresee a closed fuel cycle. The majority of the fissile nuclides (uranium, plutonium) shall be used for power generation and only fission products will be put into final disposal that needs to last for a historical time scale of only 1000 years. For the transmutation of high-level radioactive waste a lot of research and development is still required. One aspect is the precise knowledge of nuclear data for reactions with fast neutrons. Nuclear reactions relevant for transmutation are being investigated in the framework of the european project ERINDA. First results from the new neutron time-of-flight facility nELBE at Helmholtz-Zentrum Dresden-Rossendorf will be presented.

  8. High Level Control Applications for SOLEIL Commissioning and Operation

    CERN Document Server

    Nadolski, Laurent S; Ho, Katy; Leclercq, Nicolas; Ounsy, Majid; Petit, Sylvain

    2005-01-01

    The SOLEIL control system, namely TANGO developed in collaboration with ESRF, is now mature and stable. TANGO has also been chosen now by several other laboratories. High-level control applications implemented in the control room for the storage ring, the two transfer lines, and the booster will be described in this paper. Three kinds of tools for commissioning are used. First the generic TANGO tools (alarms, simple graphical control applications), which allow us to control in a simple way any TANGO Device Server. Secondly a Matlab Middle Layer (adapted from ALS and SPEAR3): Matlab is fully interconnected with TANGO; it is used primarily for writing Physics control applications. Finally Globalscreen, a commercial SCADA software devoted for building operation applications has been selected (panels for controlling or displaying setpoint, readback values, status of equipments). In addition an overview of the historical and short-term databases for the accelerators will be given. They have been developed in house...

  9. High-level waste tank farm set point document

    Energy Technology Data Exchange (ETDEWEB)

    Anthony, J.A. III

    1995-01-15

    Setpoints for nuclear safety-related instrumentation are required for actions determined by the design authorization basis. Minimum requirements need to be established for assuring that setpoints are established and held within specified limits. This document establishes the controlling methodology for changing setpoints of all classifications. The instrumentation under consideration involve the transfer, storage, and volume reduction of radioactive liquid waste in the F- and H-Area High-Level Radioactive Waste Tank Farms. The setpoint document will encompass the PROCESS AREA listed in the Safety Analysis Report (SAR) (DPSTSA-200-10 Sup 18) which includes the diversion box HDB-8 facility. In addition to the PROCESS AREAS listed in the SAR, Building 299-H and the Effluent Transfer Facility (ETF) are also included in the scope.

  10. A high-level language for rule-based modelling.

    Science.gov (United States)

    Pedersen, Michael; Phillips, Andrew; Plotkin, Gordon D

    2015-01-01

    Rule-based languages such as Kappa excel in their support for handling the combinatorial complexities prevalent in many biological systems, including signalling pathways. But Kappa provides little structure for organising rules, and large models can therefore be hard to read and maintain. This paper introduces a high-level, modular extension of Kappa called LBS-κ. We demonstrate the constructs of the language through examples and three case studies: a chemotaxis switch ring, a MAPK cascade, and an insulin signalling pathway. We then provide a formal definition of LBS-κ through an abstract syntax and a translation to plain Kappa. The translation is implemented in a compiler tool which is available as a web application. We finally demonstrate how to increase the expressivity of LBS-κ through embedded scripts in a general-purpose programming language, a technique which we view as generally applicable to other domain specific languages.

  11. Supervision of the ATLAS High Level Trigger System

    CERN Document Server

    Wheeler, S.; Meessen, C.; Qian, Z.; Touchard, F.; Negri, France A.; Zobernig, H.; CHEP 2003 Computing in High Energy Physics; Negri, France A.

    2003-01-01

    The ATLAS High Level Trigger (HLT) system provides software-based event selection after the initial LVL1 hardware trigger. It is composed of two stages, the LVL2 trigger and the Event Filter. The HLT is implemented as software tasks running on large processor farms. An essential part of the HLT is the supervision system, which is responsible for configuring, coordinating, controlling and monitoring the many hundreds of processes running in the HLT. A prototype implementation of the supervision system, using tools from the ATLAS Online Software system is presented. Results from scalability tests are also presented where the supervision system was shown to be capable of controlling over 1000 HLT processes running on 230 nodes.

  12. Review of High Level Waste Tanks Ultrasonic Inspection Data

    Energy Technology Data Exchange (ETDEWEB)

    Wiersma, B

    2006-03-09

    A review of the data collected during ultrasonic inspection of the Type I high level waste tanks has been completed. The data was analyzed for relevance to the possibility of vapor space corrosion and liquid/air interface corrosion. The review of the Type I tank UT inspection data has confirmed that the vapor space general corrosion is not an unusually aggressive phenomena and correlates well with predicted corrosion rates for steel exposed to bulk solution. The corrosion rates are seen to decrease with time as expected. The review of the temperature data did not reveal any obvious correlations between high temperatures and the occurrences of leaks. The complex nature of temperature-humidity interaction, particularly with respect to vapor corrosion requires further understanding to infer any correlation. The review of the waste level data also did not reveal any obvious correlations.

  13. Mammut: High-level management of system knobs and sensors

    Science.gov (United States)

    De Sensi, Daniele; Torquati, Massimo; Danelutto, Marco

    Managing low-level architectural features for controlling performance and power consumption is a growing demand in the parallel computing community. Such features include, but are not limited to: energy profiling, platform topology analysis, CPU cores disabling and frequency scaling. However, these low-level mechanisms are usually managed by specific tools, without any interaction between each other, thus hampering their usability. More important, most existing tools can only be used through a command line interface and they do not provide any API. Moreover, in most cases, they only allow monitoring and managing the same machine on which the tools are used. MAMMUT provides and integrates architectural management utilities through a high-level and easy-to-use object-oriented interface. By using MAMMUT, is possible to link together different collected information and to exploit them on both local and remote systems, to build architecture-aware applications.

  14. The ALICE High Level Trigger: status and plans

    CERN Document Server

    Krzewicki, Mikolaj; Gorbunov, Sergey; Breitner, Timo; Lehrbach, Johannes; Lindenstruth, Volker; Berzano, Dario

    2015-01-01

    The ALICE High Level Trigger (HLT) is an online reconstruction, triggering and data compression system used in the ALICE experiment at CERN. Unique among the LHC experiments, it extensively uses modern coprocessor technologies like general purpose graphic processing units (GPGPU) and field programmable gate arrays (FPGA) in the data flow. Realtime data compression is performed using a cluster finder algorithm implemented on FPGA boards. These data, instead of raw clusters, are used in the subsequent processing and storage, resulting in a compression factor of around 4. Track finding is performed using a cellular automaton and a Kalman filter algorithm on GPGPU hardware, where both CUDA and OpenCL technologies can be used interchangeably. The ALICE upgrade requires further development of online concepts to include detector calibration and stronger data compression. The current HLT farm will be used as a test bed for online calibration and both synchronous and asynchronous processing frameworks already before t...

  15. 4.5 Meter high level waste canister study

    Energy Technology Data Exchange (ETDEWEB)

    Calmus, R. B.

    1997-10-01

    The Tank Waste Remediation System (TWRS) Storage and Disposal Project has established the Immobilized High-Level Waste (IBLW) Storage Sub-Project to provide the capability to store Phase I and II BLW products generated by private vendors. A design/construction project, Project W-464, was established under the Sub-Project to provide the Phase I capability. Project W-464 will retrofit the Hanford Site Canister Storage Building (CSB) to accommodate the Phase I I-ILW products. Project W-464 conceptual design is currently being performed to interim store 3.0 m-long BLW stainless steel canisters with a 0.61 in diameter, DOE is considering using a 4.5 in canister of the same diameter to reduce permanent disposal costs. This study was performed to assess the impact of replacing the 3.0 in canister with the 4.5 in canister. The summary cost and schedule impacts are described.

  16. Hip Arthroscopy in High-Level Baseball Players.

    Science.gov (United States)

    Byrd, J W Thomas; Jones, Kay S

    2015-08-01

    To report the results of hip arthroscopy among high-level baseball players as recorded by outcome scores and return to baseball. All patients undergoing hip arthroscopy were prospectively assessed with the modified Harris Hip Score. On review of all procedures performed over a 12-year period, 44 hips were identified among 41 intercollegiate or professional baseball players who had achieved 2-year follow-up. Among the 41 players, follow-up averaged 45 months (range, 24 to 120 months), with a mean age of 23 years (range, 18 to 34 years). There were 23 collegiate (1 bilateral) and 18 professional (2 bilateral) baseball players, including 10 Major League Baseball players. Of the 8 Major League Baseball pitchers, 6 (75%) also underwent ulnar collateral ligament elbow surgery. Improvement in the modified Harris Hip Score averaged 13 points (from 81 points preoperatively to 94 points postoperatively); a paired-samples t test determined that this mean improvement of 13 points was statistically significant (P baseball after 42 of 44 procedures (95%) at a mean of 4.3 months (range, 3 to 8 months), with 90% regaining the ability to participate at their previous level of competition. There were no complications. Three players (1 bilateral) underwent repeat arthroscopy. This study supports the idea that arthroscopic treatment for a variety of hip pathologies in high-level baseball players provides a successful return to sport and improvement in functional outcome scores. Level IV, therapeutic case series. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  17. High level of burnout in intensivists: prevalence and associated factors.

    Science.gov (United States)

    Embriaco, Nathalie; Azoulay, Elie; Barrau, Karine; Kentish, Nancy; Pochard, Frédéric; Loundou, Anderson; Papazian, Laurent

    2007-04-01

    Professional burnout is a psychological syndrome arising in response to chronic interpersonal stressors on the job. There is the perception that intensivists are particularly exposed to stress because lives are literally in their hands. To evaluate the prevalence and associated factors (patients or organization) of burnout among physicians working in intensive care units (ICUs) (including interns, residents, fellows, and attending physicians). A 1-day national survey was conducted in adult ICUs in French public hospitals. The level of burnout was evaluated on the basis of the Maslach Burnout Inventory (MBI). A total of 189 ICUs participated and 978 surveys were returned (82.3% response rate). A high level of burnout was identified in 46.5% of the respondents. Ordinal logistic regression showed that female sex (odds ratio, 1.58; 95% confidence interval, 1.09 to 2.30) was independently associated with a higher MBI score. Whereas no factor related to the severity of illness of patients was retained by the model, organizational factors were strongly associated with a higher MBI score. Workload (the number of night shifts per month, a long period of time from the last nonworking week, night shift the day before the survey) and impaired relationships (such as conflict with another colleague intensivist, and/or with a nurse) were the variables independently associated with a higher MBI score. In contrast, the quality of the relationships with chief nurses and nurses was associated with a lower MBI score. Approximately one-half of the intensivists presented a high level of burnout. Organizational factors, but not factors related to the patients, appeared to be associated with burnout.

  18. White light generation via up-conversion and blue tone in Er3+/Tm3+/Yb3+-doped zinc-tellurite glasses

    Science.gov (United States)

    Rivera, V. A. G.; Ferri, F. A.; Nunes, L. A. O.; Marega, E.

    2017-05-01

    Yb3+, Er3+ and Tm3+ triply doped zinc-tellurite glass have been prepared containing up to 3.23 wt% of rare-earth ion oxides, were characterized by absorption spectroscopy, excitation, emission and up-conversion spectra. Transparent and homogeneous glasses have been produced, managing the red, green and blue emission bands, in order to generate white light considering the human eye perception. The energy transfer (resonant or non-resonant) between those rare-earth ions provides a color balancing mechanism that maintains the operating point in the white region, generating warm white light, cool white light and artificial daylight through the increase of the 976/980 nm diode laser excitation power from 4 to 470 mW. A light source at 4000 K is obtained under the excitation at 980 nm with 15 mW, providing a white light environment that is comfortable to the human eye vision. The spectroscopic study presented in this work describes the white light generation by the triply-doped zinc-tellurite glass, ranging from blue, green and red, by controlling the laser excitation power and wavelength at 976/980 nm. Such white tuning provokes healthy effects on human health throughout the day, especially the circadian system.

  19. 2.7 μm emission properties of Er3+ doped tungsten-tellurite glass sensitized by Yb3+ ions.

    Science.gov (United States)

    Guo, Yanyan; Ma, Yaoyao; Huang, Feifei; Peng, Yapei; Zhang, Liyan; Zhang, Junjie

    2013-07-01

    With a 980 nm laser diode (LD) pumped, the sensitized effect of Yb(3+) ions on 2.7 μm emission properties and energy transfer mechanism in Yb(3+)/Er(3+) co-doped tungsten-tellurite glass were investigated in present paper. Based on absorption spectra, Judd-Ofelt parameters and radiative transition probabilities were calculated and analyzed. The emission spectra were tested and the optimized concentration ratio of Yb(3+) to Er(3+) ions was found to be 3:0.5 with a largest calculated emission cross-section (6.05×10(-21) cm(2)) corresponding to Er(3+):(4)I11/2→(4)I13/2 transition. When the concentration ratio of Yb(3+) to Er(3+) ions was 4:0.5, 1.5 μm and 2.7 μm emission decreased while up-conversion increased. The decreased 1.5 μm and 2.7 μm emission were induced by the saturation of Er(3+):(4)I13/2 level. In brief, the advantageous spectroscopic characteristics indicated that Yb(3+)/Er(3+) co-doped tungsten-tellurite glass may be a promising candidate for application of 2.7 μm emission. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J.C.; Van Konynenburg, R.A.; McCright, R.D. (Lawrence Livermore National Lab., CA (USA)); Bullen, D.B. (Science and Engineering Associates, Inc., Pleasanton, CA (USA))

    1988-04-01

    Three iron- to nickel-based austenitic alloys (Types 304L and 316L stainless steels and Alloy 825) are being considered as candidate materials for the fabrication of high-level radioactive-waste containers. Waste will include fuel assemblies from reactors as well as high-level waste in borosilicate glass forms, and will be sent to the prospective repository at Yucca Mountain, Nevada. The decay of radionuclides in the repository will result in the generation of substantial heat and in fluences of gamma radiation. Container materials may undergo any of several modes of degradation in this environment, including atmospheric oxidation; uniform aqueous phase corrosion; pitting; crevice corrosion; sensitization and intergranular stress corrosion cracking (IGSCC); and transgranular stress corrosion cracking (TGSCC). This report is an analysis of data relevant to the pitting, crevice corrosion, and stress corrosion cracking (SCC) of the three austenitic candidate alloys. The candidates are compared in terms of their susceptibilities to these forms of corrosion. Although all three candidates have demonstrated pitting and crevice corrosion in chloride-containing environments, Alloy 825 has the greatest resistance to these types of localized corrosion (LC); such resistance is important because pits can penetrate the metal and serve as crack initiation sites. Both Types 304L and 316L stainless steels are susceptible to SCC in acidic chloride media. In contrast, SCC has not been documented in Alloy 825 under comparable conditions. Gamma radiation has been found to enhance SCC in Types 304 and 304L stainless steels, but it has no detectable effect on the resistance of Alloy 825 to SCC. Furthermore, while the effects of microbiologically induced corrosion have been observed for 300-series stainless steels, nickel-based alloys such as Alloy 825 seem to be immune to such problems. 211 refs., 49 figs., 10 tabs.

  1. Interventions for Individuals With High Levels of Needle Fear

    Science.gov (United States)

    Noel, Melanie; Taddio, Anna; Antony, Martin M.; Asmundson, Gordon J.G.; Riddell, Rebecca Pillai; Chambers, Christine T.; Shah, Vibhuti

    2015-01-01

    Background: This systematic review evaluated the effectiveness of exposure-based psychological and physical interventions for the management of high levels of needle fear and/or phobia and fainting in children and adults. Design/Methods: A systematic review identified relevant randomized and quasi-randomized controlled trials of children, adults, or both with high levels of needle fear, including phobia (if not available, then populations with other specific phobias were included). Critically important outcomes were self-reported fear specific to the feared situation and stimulus (psychological interventions) or fainting (applied muscle tension). Data were pooled using standardized mean difference (SMD) or relative risk with 95% confidence intervals. Results: The systematic review included 11 trials. In vivo exposure-based therapy for children 7 years and above showed benefit on specific fear (n=234; SMD: −1.71 [95% CI: −2.72, −0.7]). In vivo exposure-based therapy with adults reduced fear of needles posttreatment (n=20; SMD: −1.09 [−2.04, −0.14]) but not at 1-year follow-up (n=20; SMD: −0.28 [−1.16, 0.6]). Compared with single session, a benefit was observed for multiple sessions of exposure-based therapy posttreatment (n=93; SMD: −0.66 [−1.08, −0.24]) but not after 1 year (n=83; SMD: −0.37 [−0.87, 0.13]). Non in vivo e.g., imaginal exposure-based therapy in children reduced specific fear posttreatment (n=41; SMD: −0.88 [−1.7, −0.05]) and at 3 months (n=24; SMD: −0.89 [−1.73, −0.04]). Non in vivo exposure-based therapy for adults showed benefit on specific fear (n=68; SMD: −0.62 [−1.11, −0.14]) but not procedural fear (n=17; SMD: 0.18 [−0.87, 1.23]). Applied tension showed benefit on fainting posttreatment (n=20; SMD: −1.16 [−2.12, −0.19]) and after 1 year (n=20; SMD: −0.97 [−1.91, −0.03]) compared with exposure alone. Conclusions: Exposure-based psychological interventions and applied muscle tension show

  2. CEMENTITIOUS GROUT FOR CLOSING SRS HIGH LEVEL WASTE TANKS - #12315

    Energy Technology Data Exchange (ETDEWEB)

    Langton, C.; Burns, H.; Stefanko, D.

    2012-01-10

    In 1997, the first two United States Department of Energy (US DOE) high level waste tanks (Tanks 17-F and 20-F: Type IV, single shell tanks) were taken out of service (permanently closed) at the Savannah River Site (SRS). In 2012, the DOE plans to remove from service two additional Savannah River Site (SRS) Type IV high-level waste tanks, Tanks 18-F and 19-F. These tanks were constructed in the late 1950's and received low-heat waste and do not contain cooling coils. Operational closure of Tanks 18-F and 19-F is intended to be consistent with the applicable requirements of the Resource Conservation and Recovery Act (RCRA) and the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and will be performed in accordance with South Carolina Department of Health and Environmental Control (SCDHEC). The closure will physically stabilize two 4.92E+04 cubic meter (1.3 E+06 gallon) carbon steel tanks and isolate and stabilize any residual contaminants left in the tanks. The closure will also fill, physically stabilize and isolate ancillary equipment abandoned in the tanks. A Performance Assessment (PA) has been developed to assess the long-term fate and transport of residual contamination in the environment resulting from the operational closure of the F-Area Tank Farm (FTF) waste tanks. Next generation flowable, zero-bleed cementitious grouts were designed, tested, and specified for closing Tanks 18-F and 19-F and for filling the abandoned equipment. Fill requirements were developed for both the tank and equipment grouts. All grout formulations were required to be alkaline with a pH of 12.4 and chemically reduction potential (Eh) of -200 to -400 to stabilize selected potential contaminants of concern. This was achieved by including Portland cement and Grade 100 slag in the mixes, respectively. Ingredients and proportions of cementitious reagents were selected and adjusted, respectively, to support the mass placement strategy developed by

  3. The CMS High Level Trigger System: Experience and Future Development

    CERN Document Server

    Bauer, Gerry; Bowen, Matthew; Branson, James G; Bukowiec, Sebastian; Cittolin, Sergio; Coarasa, J A; Deldicque, Christian; Dobson, Marc; Dupont, Aymeric; Erhan, Samim; Flossdorf, Alexander; Gigi, Dominique; Glege, Frank; Gomez-Reino, R; Hartl, Christian; Hegeman, Jeroen; Holzner, André; Y L Hwong; Masetti, Lorenzo; Meijers, Frans; Meschi, Emilio; Mommsen, R K; O'Dell, Vivian; Orsini, Luciano; Paus, Christoph; Petrucci, Andrea; Pieri, Marco; Polese, Giovanni; Racz, Attila; Raginel, Olivier; Sakulin, Hannes; Sani, Matteo; Schwick, Christoph; Shpakov, Dennis; Simon, M; Spataru, A C; Sumorok, Konstanty

    2012-01-01

    The CMS experiment at the LHC features a two-level trigger system. Events accepted by the first level trigger, at a maximum rate of 100 kHz, are read out by the Data Acquisition system (DAQ), and subsequently assembled in memory in a farm of computers running a software high-level trigger (HLT), which selects interesting events for offline storage and analysis at a rate of order few hundred Hz. The HLT algorithms consist of sequences of offline-style reconstruction and filtering modules, executed on a farm of 0(10000) CPU cores built from commodity hardware. Experience from the operation of the HLT system in the collider run 2010/2011 is reported. The current architecture of the CMS HLT, its integration with the CMS reconstruction framework and the CMS DAQ, are discussed in the light of future development. The possible short- and medium-term evolution of the HLT software infrastructure to support extensions of the HLT computing power, and to address remaining performance and maintenance issues, are discussed.

  4. Muons in the CMS High Level Trigger System

    CERN Document Server

    AUTHOR|(CDS)2072218

    2016-01-01

    The trigger systems of LHC detectors play a fundamental role in defining the physics capabilities of the experiments. A reduction of several orders of magnitude in the rate of collected events, with respect to the proton-proton bunch crossing rate generated by the LHC, is mandatory to cope with the limits imposed by the readout and storage system. An accurate and efficient online selection mechanism is thus required to fulfill the task keeping maximal the acceptance to physics signals. The CMS experiment operates using a two-level trigger system. Firstly a Level-1 Trigger (L1T) system, implemented using custom-designed electronics, is designed to reduce the event rate to a limit compatible to the CMS Data Acquisition (DAQ) capabilities. A High Level Trigger System (HLT) follows, aimed at further reducing the rate of collected events finally stored for analysis purposes. The latter consists of a streamlined version of the CMS offline reconstruction software and operates on a computer farm. It runs algorithms o...

  5. THE HIGH LEVEL ACCESSION DIALOGUE FOR MACEDONIA: ADVANTAGES AND DISADVANTAGES

    Directory of Open Access Journals (Sweden)

    Mladen Karadjoski

    2015-04-01

    Full Text Available One of the strategic goals for the Republic of Macedonia is membership in the European Union. At the end of 2011, the Commission launched a so-called High Level Accession Dialogue for Macedonia, with a possibility to start the negotiations after the fulfillment of the Dialogue goals and benchmarks. For these reasons, the main goal of this paper will be to give an answer of the dilemma whether the Accession Dialogue for Macedonia is an accelerator of the entrance in the European Union, or is just a sophisticated tool for delay of the start of the negotiations for final accession. The expected results will correspond with the future EU plans for Macedonia, but also for the other Western Balkan countries, i.e. we will try to examine whether these countries have a realistic perspective for entrance in the European Union, or they are just a “declarative décor” for the vocabulary of the Brussels diplomats and member countries representatives. That will help to determine i.e. to try to predict the next steps of these countries, connected with the European integration, regardless of the actual constellation in the European Union concerning the Enlargement policy. The descriptive method, content analyses method, comparative method, but also the inductive and deductive methods will be used in this paper.

  6. B-tagging at High Level Trigger in CMS

    CERN Document Server

    Chabert, Eric Christian

    2014-01-01

    The CMS experiment has been designed with a 2-level trigger system. The Level 1 Trigger is implemented on custom-designed electronics. The High Level Trigger (HLT) is a streamlined version of the CMS offline reconstruction software running on a computer farm. Using b-tagging at trigger level will play a crucial role during the Run II data taking to ensure the Top quark, beyond the Standard Model and Higgs boson physics programme of the experiment. It will help to significantly reduce the trigger output rate which will increase due to the higher instantaneous luminosity and higher cross sections at 13 TeV. B-tagging algorithms based on the identification of tracks displaced from the primary proton-proton collision or on the reconstruction of secondary vertices have been successfully used during Run I. We will present their design and performance with an emphasis on the dedicated aspects of track and primary vertex reconstruction, as well as the improvements foreseen to meet the challenges of the Run II data ta...

  7. Studies of ATM for ATLAS high level triggers

    CERN Document Server

    Bystrický, J; Huet, M; Le Dû, P; Mandjavidze, I D

    2001-01-01

    This paper presents some of the conclusions of our studies on ATM and Fast Ethernet in the ATLAS level-2 trigger Pilot project. We describe the general concept and principles of our data collection and event building scheme that could be transposed to various experiments in high energy and nuclear physics. To validate the approach in view of ATLAS High Level Triggers, we assembled a testbed composed of up to 48 computers linked by a 7.5 Gbit/s ATM switch. This modular switch is used as a single entity or is split into several smaller interconnected switches. This allows studying how to construct a large network from smaller units. Alternatively, the ATM network can be replaced by Fast Ethernet. We detail the operation of the system and present series of performance measurements made with event building traffic pattern. We extrapolate these results to show how today's commercial networking components could be used to build a 1000-port network adequate for ATLAS needs. Finally, we list the benefits and the limi...

  8. The ATLAS High Level Trigger Infrastructure, Performance and Future Developments

    CERN Document Server

    Winklmeier, F; The ATLAS collaboration

    2009-01-01

    The ATLAS High Level Trigger (HLT) is a distributed real-time software system that performs the final online selection of events produced during proton-proton collisions at the Large Hadron Collider (LHC). It is designed as a two-stage event filter running on a farm of commodity PC hardware. Currently the system consists of about 850 multi-core processing nodes that will be extended incrementally following the increasing luminosity of the LHC to about 2000 nodes depending on the evolution of the processor technology. Due to the complexity and similarity of the algorithms a large fraction of the software is shared between the online and offline event reconstruction. The HLT Infrastructure serves as the interface between the two domains and provides common services for the trigger algorithms. The consequences of this design choice will be discussed and experiences from the operation of the ATLAS HLT during cosmic ray data taking and first beam in 2008 will be presented. Since the event processing time at the HL...

  9. Vestibular contributions to high-level sensorimotor functions.

    Science.gov (United States)

    Medendorp, W Pieter; Selen, Luc J P

    2017-10-01

    The vestibular system, which detects motion and orientation of the head in space, is known to be important in controlling gaze to stabilize vision, to ensure postural stability and to provide our sense of self-motion. While the brain's computations underlying these functions are extensively studied, the role of the vestibular system in higher level sensorimotor functions is less clear. This review covers new research on the vestibular influence on perceptual judgments, motor decisions, and the ability to learn multiple motor actions. Guided by concepts such as optimization, inference, estimation and control, we focus on how the brain determines causal relationships between memorized and visual representations in the updating of visual space, and how vestibular, visual and efferent motor information are integrated in the estimation of body motion. We also discuss evidence that these computations involve multiple coordinate representations, some of which can be probed in parietal cortex using neuronal oscillations derived from EEG. In addition, we describe work on decision making during self-motion, showing a clear modulation of bottom-up acceleration signals on decisions in the saccadic system. Finally, we consider the importance of vestibular signals as contextual cues in motor learning and recall. Taken together, these results emphasize the impact of vestibular information on high-level sensorimotor functions, and identify future directions for theoretical, behavioral, and neurophysiological investigations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Multi-threading in the ATLAS High-Level Trigger

    CERN Document Server

    Barton, Adam Edward; The ATLAS collaboration

    2018-01-01

    Over the next decade of LHC data-taking the instantaneous luminosity will reach up 7.5 times the design value with over 200 interactions per bunch-crossing and will pose unprecedented challenges for the ATLAS trigger system. With the evolution of the CPU market to many-core systems, both the ATLAS offline reconstruction and High-Level Trigger (HLT) software will have to transition from a multi-process to a multithreaded processing paradigm in order not to exhaust the available physical memory of a typical compute node. The new multithreaded ATLAS software framework, AthenaMT, has been designed from the ground up to support both the offline and online use-cases with the aim to further harmonize the offline and trigger algorithms. The latter is crucial both in terms of maintenance effort and to guarantee the high trigger efficiency and rejection factors needed for the next two decades of data-taking. We report on an HLT prototype in which the need for HLT­specific components has been reduced to a minimum while...

  11. Psychological stress in high level sailors during competition

    Directory of Open Access Journals (Sweden)

    L. Segato

    2010-01-01

    Full Text Available The purpose of this work was to investigate the psychological stress present in elite sailors in a competition. Based on a descriptive field research, 31 elite sailors volunteered to participate. They answered the Perceived Stress Scale (Cohen & Williamson, 1988 and also specific questions on self-control, sources and strategies of coping. Data were analyzed by using descriptive and inferential (Student t test and Pearson's correlation statistics. These athletes revealed low and moderate scores (M = 20.00, DP = 6.83 of stress originated from both intrinsic (ship troubles, team disorders and extrinsic (study, working and training, family and financial problems sources. The group reported good stress control during competition through the use of cognitive (avoidance and somatic (listening music, resting/sleeping, talk to friends strategies. It is important that sailors are able to control and cope with high levels of psychological stress and to understand how to proceed when under unstable and unexpected situations that arise during competition.

  12. The CMS High Level Trigger System: Experience and future development

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, G.; et al.

    2012-01-01

    The CMS experiment at the LHC features a two-level trigger system. Events accepted by the first level trigger, at a maximum rate of 100 kHz, are read out by the Data Acquisition system (DAQ), and subsequently assembled in memory in a farm of computers running a software high-level trigger (HLT), which selects interesting events for offline storage and analysis at a rate of order few hundred Hz. The HLT algorithms consist of sequences of offline-style reconstruction and filtering modules, executed on a farm of 0(10000) CPU cores built from commodity hardware. Experience from the operation of the HLT system in the collider run 2010/2011 is reported. The current architecture of the CMS HLT, its integration with the CMS reconstruction framework and the CMS DAQ, are discussed in the light of future development. The possible short- and medium-term evolution of the HLT software infrastructure to support extensions of the HLT computing power, and to address remaining performance and maintenance issues, are discussed.

  13. Multiple Word-Length High-Level Synthesis

    Directory of Open Access Journals (Sweden)

    Dominique Heller

    2008-09-01

    Full Text Available Digital signal processing (DSP applications are nowadays widely used and their complexity is ever growing. The design of dedicated hardware accelerators is thus still needed in system-on-chip and embedded systems. Realistic hardware implementation requires first to convert the floating-point data of the initial specification into arbitrary length data (finite-precision while keeping an acceptable computation accuracy. Next, an optimized hardware architecture has to be designed. Considering uniform bit-width specification allows to use traditional automated design flow. However, it leads to oversized design. On the other hand, considering non uniform bit-width specification allows to get a smaller circuit but requires complex design tasks. In this paper, we propose an approach that inputs a C/C++ specification. The design flow, based on high-level synthesis (HLS techniques, automatically generates a potentially pipeline RTL architecture described in VHDL. Both bitaccurate integer and fixed-point data types can be used in the input specification. The generated architecture uses components (operator, register, etc. that have different widths. The design constraints are the clock period and the throughput of the application. The proposed approach considers data word-length information in all the synthesis steps by using dedicated algorithms. We show in this paper the effectiveness of the proposed approach through several design experiments in the DSP domain.

  14. Multiple Word-Length High-Level Synthesis

    Directory of Open Access Journals (Sweden)

    Coussy Philippe

    2008-01-01

    Full Text Available Abstract Digital signal processing (DSP applications are nowadays widely used and their complexity is ever growing. The design of dedicated hardware accelerators is thus still needed in system-on-chip and embedded systems. Realistic hardware implementation requires first to convert the floating-point data of the initial specification into arbitrary length data (finite-precision while keeping an acceptable computation accuracy. Next, an optimized hardware architecture has to be designed. Considering uniform bit-width specification allows to use traditional automated design flow. However, it leads to oversized design. On the other hand, considering non uniform bit-width specification allows to get a smaller circuit but requires complex design tasks. In this paper, we propose an approach that inputs a C/C++ specification. The design flow, based on high-level synthesis (HLS techniques, automatically generates a potentially pipeline RTL architecture described in VHDL. Both bitaccurate integer and fixed-point data types can be used in the input specification. The generated architecture uses components (operator, register, etc. that have different widths. The design constraints are the clock period and the throughput of the application. The proposed approach considers data word-length information in all the synthesis steps by using dedicated algorithms. We show in this paper the effectiveness of the proposed approach through several design experiments in the DSP domain.

  15. Evaluation of the bone status in high-level cyclists.

    Science.gov (United States)

    Guillaume, Gérard; Chappard, Daniel; Audran, Maurice

    2012-01-01

    The purpose of this study was to evaluate the bone status in highly trained professional cyclists subjected to regular training and tough competitions. Bone mineral density (BMD) was measured at different regions of interest by dual-energy X-ray absorptiometry, and main biological parameters related to bone metabolism were obtained in 29 cyclists. Lumbar BMD was 0.94 ± 0.01g/cm(2) (Z-score=-1.28 ± 0.07), and 1 cyclist out of 4 had an abnormally low value (Z-score cyclists (15%) had Z-scores cyclists had low 25-hydroxyvitamin D levels. Blood testosterone and thyroid stimulating hormone were in the normal range. Insulin-like growth factor 1 levels were in the normal range; however, a significant inverse correlation was found with lumbar BMD (r=0.495; p=0.003). We confirm that cycling has no positive effect on BMD, BMD being often lower than in normal controls at the lumbar site; femoral BMD is less concerned. The absence of beneficial changes at the spine can be explained by biomechanical conditions related to the cyclists' position, reducing loading strains. It is necessary to pay greater attention to the bone status of high-level athletes to prevent an increased risk of fractures. Copyright © 2012 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

  16. Studies of ATM for ATLAS high-level triggers

    CERN Document Server

    Bystrický, J; Huet, M; Le Dû, P; Mandjavidze, I D

    2001-01-01

    This paper presents some of the conclusions of our studies on asynchronous transfer mode (ATM) and fast Ethernet in the ATLAS level-2 trigger pilot project. We describe the general concept and principles of our data-collection and event-building scheme that could be transposed to various experiments in high-energy and nuclear physics. To validate the approach in view of ATLAS high-level triggers, we assembled a testbed composed of up to 48 computers linked by a 7.5-Gbit/s ATM switch. This modular switch is used as a single entity or is split into several smaller interconnected switches. This allows study of how to construct a large network from smaller units. Alternatively, the ATM network can be replaced by fast Ethernet. We detail the operation of the system and present series of performance measurements made with event-building traffic pattern. We extrapolate these results to show how today's commercial networking components could be used to build a 1000-port network adequate for ATLAS needs. Lastly, we li...

  17. A readout buffer prototype for ATLAS high-level triggers

    CERN Document Server

    Calvet, D; Huet, M; Le Dû, P; Mandjavidze, I D; Mur, M

    2001-01-01

    Readout buffers are critical components in the dataflow chain of the ATLAS trigger/data-acquisition system. At up to 75 kHz, after each Level-1 trigger accept signal, these devices receive and store digitized data from groups of front-end electronic channels. Several readout buffers are grouped to form a readout buffer complex that acts as a data server for the high-level trigger selection algorithms and for the final data-collection system. This paper describes a functional prototype of a readout buffer based on a custom-made PCI mezzanine card that is designed to accept input data at up to 160 MB /s, to store up to 8 MB of data, and to distribute data chunks at the desired request rate. We describe the hardware of the card that is based on an Intel 1960 processor and complex programmable logic devices. We present the integration of several of these cards in a readout buffer complex. We measure various performance figures and discuss to which extent these can fulfil ATLAS needs. (5 refs).

  18. Identification of areas with high levels of untreated dental caries.

    Science.gov (United States)

    Ellwood, R P; O'Mullane, D M

    1996-02-01

    In order to examine the geographical variation of dental health within 10 county districts in North Wales, 3538 children were examined. The associations between three demographic indicators, based on the 1981 OPCS census, and dental health outcomes were assessed for electoral wards within the county districts. The Townsend and Jarman indices were the first two indicators employed and the third was based on a mathematical model representing the variation in the mean number of untreated decayed surfaces per person for the wards. This model was developed using the children examined in the five most westerly county districts. Using the data derived from the five most easterly county districts, the three indicators were assessed. All three showed strong correlations (r > or = 0.88) with dental health. These results indicate that measures of dental health based on large administrative units may obscure variation within them. It is concluded that geographical methods of this type may be useful for targeting dental resources at small areas with high levels of need.

  19. High-level fluorescence labeling of gram-positive pathogens.

    Directory of Open Access Journals (Sweden)

    Simone Aymanns

    Full Text Available Fluorescence labeling of bacterial pathogens has a broad range of interesting applications including the observation of living bacteria within host cells. We constructed a novel vector based on the E. coli streptococcal shuttle plasmid pAT28 that can propagate in numerous bacterial species from different genera. The plasmid harbors a promoterless copy of the green fluorescent variant gene egfp under the control of the CAMP-factor gene (cfb promoter of Streptococcus agalactiae and was designated pBSU101. Upon transfer of the plasmid into streptococci, the bacteria show a distinct and easily detectable fluorescence using a standard fluorescence microscope and quantification by FACS-analysis demonstrated values that were 10-50 times increased over the respective controls. To assess the suitability of the construct for high efficiency fluorescence labeling in different gram-positive pathogens, numerous species were transformed. We successfully labeled Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus dysgalactiae subsp. equisimilis, Enterococcus faecalis, Enterococcus faecium, Streptococcus mutans, Streptococcus anginosus and Staphylococcus aureus strains utilizing the EGFP reporter plasmid pBSU101. In all of these species the presence of the cfb promoter construct resulted in high-level EGFP expression that could be further increased by growing the streptococcal and enterococcal cultures under high oxygen conditions through continuous aeration.

  20. The Software Architecture of the LHCb High Level Trigger

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    The LHCb experiment is a spectrometer dedicated to the study of heavy flavor at the LHC. The rate of proton-proton collisions at the LHC is 15 MHz, but disk space limitations mean that only 3 kHz can be written to tape for offline processing. For this reason the LHCb data acquisition system -- trigger -- plays a key role in selecting signal events and rejecting background. In contrast to previous experiments at hadron colliders like for example CDF or D0, the bulk of the LHCb trigger is implemented in software and deployed on a farm of 20k parallel processing nodes. This system, called the High Level Trigger (HLT) is responsible for reducing the rate from the maximum at which the detector can be read out, 1.1 MHz, to the 3 kHz which can be processed offline,and has 20 ms in which to process and accept/reject each event. In order to minimize systematic uncertainties, the HLT was designed from the outset to reuse the offline reconstruction and selection code, and is based around multiple independent and redunda...

  1. Defense High-Level Waste Leaching Mechanisms Program. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mendel, J.E. (compiler)

    1984-08-01

    The Defense High-Level Waste Leaching Mechanisms Program brought six major US laboratories together for three years of cooperative research. The participants reached a consensus that solubility of the leached glass species, particularly solubility in the altered surface layer, is the dominant factor controlling the leaching behavior of defense waste glass in a system in which the flow of leachant is constrained, as it will be in a deep geologic repository. Also, once the surface of waste glass is contacted by ground water, the kinetics of establishing solubility control are relatively rapid. The concentrations of leached species reach saturation, or steady-state concentrations, within a few months to a year at 70 to 90/sup 0/C. Thus, reaction kinetics, which were the main subject of earlier leaching mechanisms studies, are now shown to assume much less importance. The dominance of solubility means that the leach rate is, in fact, directly proportional to ground water flow rate. Doubling the flow rate doubles the effective leach rate. This relationship is expected to obtain in most, if not all, repository situations.

  2. Control of high-level radioactive waste-glass melters

    Energy Technology Data Exchange (ETDEWEB)

    Bickford, D.F.; Coleman, C.J.

    1990-01-01

    The Defense Waste Processing Facility (DWPF) will immobilize Savannah River Site High Level Waste as a durable borosilicate glass for permanent disposal in a repository. The DWPF will be controlled based on glass composition. The following discussion is a preliminary analysis of the capability of the laboratory methods that can be used to control the glass composition, and the relationships between glass durability and glass properties important to glass melting. The glass durability and processing properties will be controlled by controlling the chemical composition of the glass. The glass composition will be controlled by control of the melter feed transferred from the Slurry Mix Evaporator (SME) to the Melter Feed Tank (MFT). During cold runs, tests will be conducted to demonstrate the chemical equivalence of glass sampled from the pour stream and glass removed from cooled canisters. In similar tests, the compositions of glass produced from slurries sampled from the SME and MFT will be compared to final product glass to determine the statistical relationships between melter feed and glass product. The total error is the combination of those associated with homogeneity in the SME or MFT, sampling, preparation of samples for analysis, instrument calibration, analysis, and the composition/property model. This study investigated the sensitivity of estimation of property data to the combination of variations from sampling through analysis. In this or a similar manner, the need for routine glass product sampling will be minimized, and glass product characteristics will be assured before the melter feed is committed to the melter.

  3. Psychological stress in high level sailors during competition

    Directory of Open Access Journals (Sweden)

    Luciana Segato

    2010-09-01

    Full Text Available The purpose of this work was to investigate the psychological stress present in elite sailors in a competition. Based on a descriptive field research, 31 elite sailors volunteered to participate. They answered the Perceived Stress Scale (Cohen & Williamson, 1988 and also specific questions on self-control, sources and strategies of coping. Data were analyzed by using descriptive and inferential (Student t test and Pearson's correlation statistics. These athletes revealed low and moderate scores (M = 20.00, DP = 6.83 of stress originated from both intrinsic (ship troubles, team disorders and extrinsic (study, working and training, family and financial problems sources. The group reported good stress control during competition through the use of cognitive (avoidance and somatic (listening music, resting/sleeping, talk to friends strategies. It is important that sailors are able to control and cope with high levels of psychological stress and to understand how to proceed when under unstable and unexpected situations that arise during competition.

  4. Process Design Concepts for Stabilization of High Level Waste Calcine

    Energy Technology Data Exchange (ETDEWEB)

    T. R. Thomas; A. K. Herbst

    2005-06-01

    The current baseline assumption is that packaging ¡§as is¡¨ and direct disposal of high level waste (HLW) calcine in a Monitored Geologic Repository will be allowed. The fall back position is to develop a stabilized waste form for the HLW calcine, that will meet repository waste acceptance criteria currently in place, in case regulatory initiatives are unsuccessful. A decision between direct disposal or a stabilization alternative is anticipated by June 2006. The purposes of this Engineering Design File (EDF) are to provide a pre-conceptual design on three low temperature processes under development for stabilization of high level waste calcine (i.e., the grout, hydroceramic grout, and iron phosphate ceramic processes) and to support a down selection among the three candidates. The key assumptions for the pre-conceptual design assessment are that a) a waste treatment plant would operate over eight years for 200 days a year, b) a design processing rate of 3.67 m3/day or 4670 kg/day of HLW calcine would be needed, and c) the performance of waste form would remove the HLW calcine from the hazardous waste category, and d) the waste form loadings would range from about 21-25 wt% calcine. The conclusions of this EDF study are that: (a) To date, the grout formulation appears to be the best candidate stabilizer among the three being tested for HLW calcine and appears to be the easiest to mix, pour, and cure. (b) Only minor differences would exist between the process steps of the grout and hydroceramic grout stabilization processes. If temperature control of the mixer at about 80„aC is required, it would add a major level of complexity to the iron phosphate stabilization process. (c) It is too early in the development program to determine which stabilizer will produce the minimum amount of stabilized waste form for the entire HLW inventory, but the volume is assumed to be within the range of 12,250 to 14,470 m3. (d) The stacked vessel height of the hot process vessels

  5. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    Energy Technology Data Exchange (ETDEWEB)

    Gdowski, G.E.; Bullen, D.B. (Science and Engineering Associates, Inc., Pleasanton, CA (USA))

    1988-08-01

    Three copper-based alloys and three iron- to nickel-based austenitic alloys are being considered as possible materials for fabrication of containers for disposal of high-level radioactive waste. This waste will include spent fuel assemblies from reactors as well as high-level waste in borosilicate glass and will be sent to the prospective site at Yucca Mountain, Nevada, for disposal. The containers must maintain substantially complete containment for at least 300 yr and perhaps as long as 1000 yr. During the first 50 yr after emplacement, they must be retrievable from the disposal site. Shortly after the containers are emplaced in the repository, they will be exposed to high temperatures and high gamma radiation fields from the decay of the high-level waste. This volume surveys the available data on oxidation and corrosion of the iron- to nickel-based austenitic materials (Types 304L and 316L stainless steels and Alloy 825) and the copper-based alloy materials (CDA 102 (oxygen-free copper), CDA 613 (Cu-7Al), and CDA 715 (Cu-30Ni)), which are the present candidates for fabrication of the containers. Studies that provided a large amount of data are highlighted, and those areas in which little data exists are identified. Examples of successful applications of these materials are given. On the basis of resistance to oxidation and general corrosion, the austenitic materials are ranked as follows: Alloy 825 (best), Type 316L stainless steel, and then Type 304L stainless steel (worst). For the copper-based materials, the ranking is as follows: CDA 715 and CDA 613 (both best), and CDA 102 (worst). 110 refs., 30 figs., 13 tabs.

  6. PLUTONIUM/HIGH-LEVEL VITRIFIED WASTE BDBE DOSE CALCULATION

    Energy Technology Data Exchange (ETDEWEB)

    D.C. Richardson

    2003-03-19

    In accordance with the Nuclear Waste Policy Amendments Act of 1987, Yucca Mountain was designated as the site to be investigated as a potential repository for the disposal of high-level radioactive waste. The Yucca Mountain site is an undeveloped area located on the southwestern edge of the Nevada Test Site (NTS), about 100 miles northwest of Las Vegas. The site currently lacks rail service or an existing right-of-way. If the Yucca Mountain site is found suitable for the repository, rail service is desirable to the Office of Civilian Waste Management (OCRWM) Program because of the potential of rail transportation to reduce costs and to reduce the number of shipments relative to highway transportation. A Preliminary Rail Access Study evaluated 13 potential rail spur options. Alternative routes within the major options were also developed. Each of these options was then evaluated for potential land use conflicts and access to regional rail carriers. Three potential routes having few land use conflicts and having access to regional carriers were recommended for further investigation. Figure 1-1 shows these three routes. The Jean route is estimated to be about 120 miles long, the Carlin route to be about 365 miles long, and Caliente route to be about 365 miles long. The remaining ten routes continue to be monitored and should any of the present conflicts change, a re-evaluation of that route will be made. Complete details of the evaluation of the 13 routes can be found in the previous study. The DOE has not identified any preferred route and recognizes that the transportation issues need a full and open treatment under the National Environmental Policy Act. The issue of transportation will be included in public hearings to support development of the Environmental Impact Statement (EIS) proceedings for either the Monitored Retrievable Storage Facility or the Yucca Mountain Project or both.

  7. High level secretion of cellobiohydrolases by Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Ahlgren Simon

    2011-09-01

    Full Text Available Abstract Background The main technological impediment to widespread utilization of lignocellulose for the production of fuels and chemicals is the lack of low-cost technologies to overcome its recalcitrance. Organisms that hydrolyze lignocellulose and produce a valuable product such as ethanol at a high rate and titer could significantly reduce the costs of biomass conversion technologies, and will allow separate conversion steps to be combined in a consolidated bioprocess (CBP. Development of Saccharomyces cerevisiae for CBP requires the high level secretion of cellulases, particularly cellobiohydrolases. Results We expressed various cellobiohydrolases to identify enzymes that were efficiently secreted by S. cerevisiae. For enhanced cellulose hydrolysis, we engineered bimodular derivatives of a well secreted enzyme that naturally lacks the carbohydrate-binding module, and constructed strains expressing combinations of cbh1 and cbh2 genes. Though there was significant variability in the enzyme levels produced, up to approximately 0.3 g/L CBH1 and approximately 1 g/L CBH2 could be produced in high cell density fermentations. Furthermore, we could show activation of the unfolded protein response as a result of cellobiohydrolase production. Finally, we report fermentation of microcrystalline cellulose (Avicel™ to ethanol by CBH-producing S. cerevisiae strains with the addition of beta-glucosidase. Conclusions Gene or protein specific features and compatibility with the host are important for efficient cellobiohydrolase secretion in yeast. The present work demonstrated that production of both CBH1 and CBH2 could be improved to levels where the barrier to CBH sufficiency in the hydrolysis of cellulose was overcome.

  8. Muons in the CMS High Level Trigger System

    Science.gov (United States)

    Verwilligen, Piet; CMS Collaboration

    2016-04-01

    The trigger systems of LHC detectors play a fundamental role in defining the physics capabilities of the experiments. A reduction of several orders of magnitude in the rate of collected events, with respect to the proton-proton bunch crossing rate generated by the LHC, is mandatory to cope with the limits imposed by the readout and storage system. An accurate and efficient online selection mechanism is thus required to fulfill the task keeping maximal the acceptance to physics signals. The CMS experiment operates using a two-level trigger system. Firstly a Level-1 Trigger (L1T) system, implemented using custom-designed electronics, is designed to reduce the event rate to a limit compatible to the CMS Data Acquisition (DAQ) capabilities. A High Level Trigger System (HLT) follows, aimed at further reducing the rate of collected events finally stored for analysis purposes. The latter consists of a streamlined version of the CMS offline reconstruction software and operates on a computer farm. It runs algorithms optimized to make a trade-off between computational complexity, rate reduction and high selection efficiency. With the computing power available in 2012 the maximum reconstruction time at HLT was about 200 ms per event, at the nominal L1T rate of 100 kHz. An efficient selection of muons at HLT, as well as an accurate measurement of their properties, such as transverse momentum and isolation, is fundamental for the CMS physics programme. The performance of the muon HLT for single and double muon triggers achieved in Run I will be presented. Results from new developments, aimed at improving the performance of the algorithms for the harsher scenarios of collisions per event (pile-up) and luminosity expected for Run II will also be discussed.

  9. High levels of serum hyaluronic acid in adults with dermatomyositis

    Directory of Open Access Journals (Sweden)

    Alana Ausciutti Victorino

    2015-04-01

    Full Text Available Background / objectives. Hyaluronic acid (HA is rarely described in dermatomyositis (DM. Thus, we determined any clinical association of serum levels of hyaluronic acid (HA in patients with dermatomyositis (DM. Materials and Methods. This cross-sectional single-center analysis 75 DM and 75 healthy individuals, during the period from January 2012 to July 2013. An anti-HA antibody assay was performed using specific ELISA/EIA kits, according to the manufacturer’s protocol. Results. The patients with DM and control subjects had comparable demographic distributions (p>0.05. The median time duration between disease diagnosis and initial symptoms was 6.0 [3.0-12.0] months, with a median DM disease duration of 4.0 [1.0-7.0] years. The median level of serum HA was significantly increased in patients with DM compared to the control group [329.0 (80.0-958.0 vs. 133.0 (30.0-262.0 ng/mL, respectively; p0.05. Serum HA also did not correlate with gender, ethnicity, auto-antibodies or drug use (p>0.05, but did correlate with cutaneous features, such as photosensitivity (p=0.001, “shawl” sign (p=0.018, “V-neck” sign (p=0.005 and cuticular hypertrophy (p=0.014. Conclusions. A high level of serum AH was observed in DM compared to healthy individuals. In DM, HA did not correlate to demographic, auto-antibodies and therapy parameters. However, HA correlated specifically with some cutaneous features, suggesting that this glycosaminoglycan could be involved in modulating cutaneous inflammation in this population. More studies are necessary to understand the correlation between AH and patients with DM.

  10. Lumbar disc herniation at high levels : MRI and clinical findings

    Energy Technology Data Exchange (ETDEWEB)

    Paek, Chung Ho; Kwon, Soon Tae; Lee, Jun Kyu; Ahn, Jae Sung; Lee, Hwan Do; Chung, Yon Su; Jeong, Ki Ho; Cho, Jun Sik [Chungnam National Univ. College of Medicine, Taejon (Korea, Republic of)

    1999-04-01

    To assess the frequency, location, associated MR findings, and clinical symptoms of the high level lumbar disc herniation(HLDH). A total of 1076 patients with lunbar disc herniation were retrospectively reviewed. MR images of 41 of these with HLDH(T12-L1, L1-2, L2-3) were analysed in terms of frequency, location, and associated MR findings, and correlated with clinical symptoms of HLDH. The prevalence of HLDH was 3.8%(41/1076). HLDH was located at T12-L1 level in four patients(10%), at L1-2 level in 14(34%), at L2-3 level in 21(51%), and at both L1-2 and L2-3 levels in two. The age of patients ranged from 20 to 72 years (mean, 44), and there were 26 men and 16 women. In 11(27%), whose mean age was 32 years, isolated disc herniation was limited to these high lumbar segments. The remaining 30 patients had HLDH associated with variable involvement of the lower lumbar segments. Associated lesions were as follow : lower level disc herniation(14 patients, 34%); apophyseal ring fracture(8 patients, 19%); Schmorl's node and spondylolisthesis (each 6 patients, each 14%); spondylolysis(3 patients, 7%); and retrolisthesis(2 patients, 5%). In 20 patients(49%) with HLDH(n=41), there was a previous history of trauma. Patients with HLDH showed a relatively high incidence of associated coexisting abnormalities such as lower lumbar disc herniation, apophyseal ring fracture, Schmorl's node, spondylolysis, and retrolisthesis. In about half of all patients with HLDH there was a previous history of trauma. The mean age of patients with isolated HLDH was lower; clinical symptoms of the condition were relatively nonspecific and their incidence was low.

  11. Stability of High-Level Radioactive Waste Forms

    Energy Technology Data Exchange (ETDEWEB)

    Besmann, T.M.

    2001-06-22

    High-level waste (HLW) glass compositions, processing schemes, limits on waste content, and corrosion/dissolution release models are dependent on an accurate knowledge of melting temperatures and thermochemical values. Unfortunately, existing models for predicting these temperatures are empirically-based, depending on extrapolations of experimental information. In addition, present models of leaching behavior of glass waste forms use simplistic assumptions or experimentally measured values obtained under non-realistic conditions. There is thus a critical need for both more accurate and more widely applicable models for HLW glass behavior, which this project addressed. Significant progress was made in this project on modeling HLW glass. Borosilicate glass was accurately represented along with the additional important components that contain iron, lithium, potassium, magnesium, and calcium. The formation of crystalline inclusions in the glass, an issue in Hanford HLW formulations, was modeled and shown to be predictive. Thus the results of this work have already demonstrated practical benefits with the ability to map compositional regions where crystalline material forms, and therefore avoid that detrimental effect. With regard to a fundamental understanding, added insights on the behavior of the components of glass have been obtained, including the potential formation of molecular clusters. The EMSP project had very significant effects beyond the confines of Environmental Management. The models developed for glass have been used to solve a very costly problem in the corrosion of refractories for glass production. The effort resulted in another laboratory, Sandia National Laboratories-Livermore, to become conversant in the techniques and to apply those through a DOE Office of Industrial Technologies project joint with PPG Industries. The glass industry as a whole is now cognizant of these capabilities, and there is a Glass Manufacturer's Research Institute

  12. Modeling the corrosion of high-level waste containers: CAM-CRM interface

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J.C.; Bedrossian, P.J.; McCright, R.D.

    1998-06-01

    A key component of the Engineered Barrier System (EBS) being designed for containment of spent-fuel and high-level waste at the proposed geological respository at Yucca Mountain, Nevada is a two-layer canister. In this particular design, the inner barrier is made of a corrosion resistant material (CRM) such as Alloy 825, 625 or C-22, while the outer barrier is made of a corrosion-allowance material (CAM) such as A516 or Monel 400. At the present time, Alloy C-22 and A516 are favored. This publication addresses the development of models to account for corrosion of Alloy C-22 surfaces exposed directly to the Near Field Environmental (NFE), as well as to the exacerbated conditions in the CAM-CRM crevice.

  13. High-Level Functional and Operational Requirements for the Advanced Fuel Cycle Facilty

    Energy Technology Data Exchange (ETDEWEB)

    Charles Park

    2006-12-01

    High-Level Functional & Operational Requirements for the AFCF -This document describes the principal functional and operational requirements for the proposed Advanced Fuel Cycle Facility (AFCF). The AFCF is intended to be the world's foremost facility for nuclear fuel cycle research, technology development, and demonstration. The facility will also support the near-term mission to develop and demonstrate technology in support of fuel cycle needs identified by industry, and the long-term mission to retain and retain U.S. leadership in fuel cycle operations. The AFCF is essential to demonstrate a more proliferation-resistant fuel cycle and make long-term improvements in fuel cycle effectiveness, performance and economy.

  14. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    Energy Technology Data Exchange (ETDEWEB)

    Strum, M.J.; Weiss, H.; Farmer, J.C. (Lawrence Livermore National Lab., CA (USA)); Bullen, D.B. (Science and Engineering Associates, Inc., Pleasanton, CA (USA))

    1988-06-01

    This volume surveys the effects of welding on the degradation modes of three austenitic alloys: Types 304L and 316L stainless steels and Alloy 825. These materials are candidates for the fabrication of containers for the long-term storage of high-level nuclear waste. The metallurgical characteristics of fusion welds are reviewed here and related to potential degradation modes of the containers. Three specific areas are discussed in depth: (1) decreased resistance to corrosion in the forms of preferential corrosion, sensitization, and susceptibility to stress corrosion cracking, (2) hot cracking in the heat-affected zone and the weld zone, and (3) formation of intermetallic phases. The austenitic alloys are ranked as follows in terms of overall weldability: Alloy 825 (best) > Type 316L stainless steel > Type 304L stainless steel (worst). 108 refs., 31 figs., 7 tabs.

  15. Tm3+/Yb3+ co-doped tellurite glass with silver nanoparticles for 1.85 μm band laser material

    Science.gov (United States)

    Huang, Bo; Zhou, Yaxun; Cheng, Pan; Zhou, Zizhong; Li, Jun; Jin, Wei

    2016-10-01

    Tm3+/Yb3+ co-doped tellurite glasses with different silver nanoparticles (Ag NPs) concentrations were prepared using the conventional melt-quenching technique and characterized by the UV/Vis/NIR absorption spectra, 1.85 μm band fluorescence emission spectra, transmission electron microscopy (TEM) images, differential scanning calorimeter (DSC) curves and X-ray diffraction (XRD) patterns to investigate the effects of Ag NPs on the 1.85 μm band spectroscopic properties of Tm3+ ions, thermal stability and structural nature of glass hosts. Under the excitation of 980 nm laser diode (LD), the 1.85 μm band fluorescence emission of Tm3+ ions enhances significantly in the presence of Ag NPs with average diameter of ∼8 nm and local surface Plasmon resonance (LSPR) band of ∼590 nm, which is mainly attributed to the increased local electric field induced by Ag NPs at the proximity of doped rare-earth ions on the basis of energy transfer from Yb3+ to Tm3+ ions. An improvement by about 110% of fluorescence intensity is observed in the Tm3+/Yb3+ co-doped tellurite glass containing 0.5 mol% amount of AgNO3 while the prepared glass samples possess good thermal stability and amorphous structural nature. Meanwhile, the Judd-Ofelt intensity parameters Ωt (t = 2,4,6), spontaneous radiative transition probabilities, fluorescence branching ratios and radiative lifetimes of relevant excited levels of Tm3+ ions were determined based on the Judd-Ofelt theory to reveal the enhanced effects of Ag NPs on the 1.85 μm band spectroscopic properties, and the energy transfer micro-parameters and phonon contribution ratios were calculated based on the non-resonant energy transfer theory to elucidate the energy transfer mechanism between Yb3+ and Tm3+ ions. The present results indicate that the prepared Tm3+/Yb3+ co-doped tellurite glass with an appropriate amount of Ag NPs is a promising lasing media applied for 1.85 μm band solid-state lasers and amplifiers.

  16. Engineering neural systems for high-level problem solving.

    Science.gov (United States)

    Sylvester, Jared; Reggia, James

    2016-07-01

    There is a long-standing, sometimes contentious debate in AI concerning the relative merits of a symbolic, top-down approach vs. a neural, bottom-up approach to engineering intelligent machine behaviors. While neurocomputational methods excel at lower-level cognitive tasks (incremental learning for pattern classification, low-level sensorimotor control, fault tolerance and processing of noisy data, etc.), they are largely non-competitive with top-down symbolic methods for tasks involving high-level cognitive problem solving (goal-directed reasoning, metacognition, planning, etc.). Here we take a step towards addressing this limitation by developing a purely neural framework named galis. Our goal in this work is to integrate top-down (non-symbolic) control of a neural network system with more traditional bottom-up neural computations. galis is based on attractor networks that can be "programmed" with temporal sequences of hand-crafted instructions that control problem solving by gating the activity retention of, communication between, and learning done by other neural networks. We demonstrate the effectiveness of this approach by showing that it can be applied successfully to solve sequential card matching problems, using both human performance and a top-down symbolic algorithm as experimental controls. Solving this kind of problem makes use of top-down attention control and the binding together of visual features in ways that are easy for symbolic AI systems but not for neural networks to achieve. Our model can not only be instructed on how to solve card matching problems successfully, but its performance also qualitatively (and sometimes quantitatively) matches the performance of both human subjects that we had perform the same task and the top-down symbolic algorithm that we used as an experimental control. We conclude that the core principles underlying the galis framework provide a promising approach to engineering purely neurocomputational systems for problem

  17. Advanced High-Level Waste Glass Research and Development Plan

    Energy Technology Data Exchange (ETDEWEB)

    Peeler, David K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Vienna, John D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Schweiger, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fox, Kevin M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-07-01

    The U.S. Department of Energy Office of River Protection (ORP) has implemented an integrated program to increase the loading of Hanford tank wastes in glass while meeting melter lifetime expectancies and process, regulatory, and product quality requirements. The integrated ORP program is focused on providing a technical, science-based foundation from which key decisions can be made regarding the successful operation of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) facilities. The fundamental data stemming from this program will support development of advanced glass formulations, key process control models, and tactical processing strategies to ensure safe and successful operations for both the low-activity waste (LAW) and high-level waste (HLW) vitrification facilities with an appreciation toward reducing overall mission life. The purpose of this advanced HLW glass research and development plan is to identify the near-, mid-, and longer-term research and development activities required to develop and validate advanced HLW glasses and their associated models to support facility operations at WTP, including both direct feed and full pretreatment flowsheets. This plan also integrates technical support of facility operations and waste qualification activities to show the interdependence of these activities with the advanced waste glass (AWG) program to support the full WTP mission. Figure ES-1 shows these key ORP programmatic activities and their interfaces with both WTP facility operations and qualification needs. The plan is a living document that will be updated to reflect key advancements and mission strategy changes. The research outlined here is motivated by the potential for substantial economic benefits (e.g., significant increases in waste throughput and reductions in glass volumes) that will be realized when advancements in glass formulation continue and models supporting facility operations are implemented. Developing and applying advanced

  18. Camptothecin resistance

    DEFF Research Database (Denmark)

    Brangi, M; Litman, Thomas; Ciotti, M

    1999-01-01

    The mitoxantrone resistance (MXR) gene encodes a recently characterized ATP-binding cassette half-transporter that confers multidrug resistance. We studied resistance to the camptothecins in two sublines expressing high levels of MXR: S1-M1-80 cells derived from parental S1 colon cancer cells...... and MCF-7 AdVp3,000 isolated from parental MCF-7 breast cancer cells. Both cell lines were 400- to 1,000-fold more resistant to topotecan, 9-amino-20(S)-camptothecin, and the active metabolite of irinotecan, 7-ethyl-10-hydroxycamptothecin (SN-38), than their parental cell lines. The cell lines...... demonstrated much less resistance to camptothecin and to several camptothecin analogues. Reduced accumulation and energy-dependent efflux of topotecan was demonstrated by confocal microscopy. A significant reduction in cleavable complexes in the resistant cells could be observed after SN-38 treatment...

  19. New tellurite glasses and crystalline phases in the Bi{sub 2}O{sub 3}-CaO-TeO{sub 2} system: Synthesis and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Chagraoui, Abdeslam; Tairi, Abdelmjid; Ajebli, Kaltoum; Bensaid, Hanane; Moussaoui, Abdenajib [Laboratoire de Chimie Analytique et Physico-chimie des Materiaux, Departement de Chimie, Faculte des Sciences Ben M' sik, Universite HassanII-Mohammedia Casablanca (Morocco)

    2010-04-09

    Tellurite glasses containing calcium and bismuth oxides have been prepared at 800 {sup o}C and investigated by X-ray diffraction, DSC, IR and Raman spectroscopy. The crystalline phases of glasses in TeO{sub 2}-CaO revealed {gamma}TeO{sub 2} phase which transforms into the stable {alpha}TeO{sub 2} phase up to 500 {sup o}C. IR and Raman studies show the transition of TeO{sub 4}, TeO{sub 3+1} and TeO{sub 3} units with increasing CaO content. The value of refractive index and density of glasses have been measured. The investigation in the system using XRD reveals new phases.

  20. Anticipated Degradation Modes of Metallic Engineered Barriers for High-Level Nuclear Waste Repositories

    Science.gov (United States)

    Rodríguez, Martín A.

    2014-03-01

    Metallic engineered barriers must provide a period of absolute containment to high-level radioactive waste in geological repositories. Candidate materials include copper alloys, carbon steels, stainless steels, nickel alloys, and titanium alloys. The national programs of nuclear waste management have to identify and assess the anticipated degradation modes of the selected materials in the corresponding repository environment, which evolves in time. Commonly assessed degradation modes include general corrosion, localized corrosion, stress-corrosion cracking, hydrogen-assisted cracking, and microbiologically influenced corrosion. Laboratory testing and modeling in metallurgical and environmental conditions of similar and higher aggressiveness than those expected in service conditions are used to evaluate the corrosion resistance of the materials. This review focuses on the anticipated degradation modes of the selected or reference materials as corrosion-resistant barriers in nuclear repositories. These degradation modes depend not only on the selected alloy but also on the near-field environment. The evolution of the near-field environment varies for saturated and unsaturated repositories considering backfilled and unbackfilled conditions. In saturated repositories, localized corrosion and stress-corrosion cracking may occur in the initial aerobic stage, while general corrosion and hydrogen-assisted cracking are the main degradation modes in the anaerobic stage. Unsaturated repositories would provide an oxidizing environment during the entire repository lifetime. Microbiologically influenced corrosion may be avoided or minimized by selecting an appropriate backfill material. Radiation effects are negligible provided that a thick-walled container or an inner shielding container is used.

  1. Corrosion of container materials for disposal of high-level radioactive wastes

    Energy Technology Data Exchange (ETDEWEB)

    Chun, K.S.; Park, H.S.; Yeon, J.W.; Ha, Y.K. [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-01-01

    In the corrosion aspect of container for the deep geological disposal of high-level radioactive waste, disposal concepts and the related container materials, which have been developed by advanced countries, have been reviewed. The disposal circumstances could be divided into the saturated and the unsaturated zones. The candidate materials in the countries, which consider the disposal in the unsaturated zone, are the corrosion resistant materials such as supper alloys and stainless steels, but those in the saturated zone is cupper, one of the corrosion allowable materials. By the results of the pitting corrosion test of sensitized stainless steels (such as 304, 304L, 316 and 316L), pitting potential is decreased with the degree of sensitization and the pitting corrosion resistance of 316L is higher than others. And so, the long-term corrosion experiment with 316L stainless steel specimens, sebsitized and non-sensitized, under the compacted bentonite and synthetic granitic groundwater has been being carried out. The results from the experiment for 12 months indicate that no evidence of pitting corrosion of the specimens has been observed but the crevice corrosion has occurred on the sensitized specimens even for 3 months. (author). 33 refs., 19 figs., 10 tabs.

  2. Randomized Comparison of 3 High-Level Disinfection and Sterilization Procedures for Duodenoscopes.

    Science.gov (United States)

    Snyder, Graham M; Wright, Sharon B; Smithey, Anne; Mizrahi, Meir; Sheppard, Michelle; Hirsch, Elizabeth B; Chuttani, Ram; Heroux, Riley; Yassa, David S; Olafsdottir, Lovisa B; Davis, Roger B; Anastasiou, Jiannis; Bapat, Vijay; Bidari, Kiran; Pleskow, Douglas K; Leffler, Daniel; Lane, Benjamin; Chen, Alice; Gold, Howard S; Bartley, Anthony; King, Aleah D; Sawhney, Mandeep S

    2017-10-01

    Duodenoscopes have been implicated in the transmission of multidrug-resistant organisms (MDRO). We compared the frequency of duodenoscope contamination with MDRO or any other bacteria after disinfection or sterilization by 3 different methods. We performed a single-center prospective randomized study in which duodenoscopes were randomly reprocessed by standard high-level disinfection (sHLD), double high-level disinfection (dHLD), or standard high-level disinfection followed by ethylene oxide gas sterilization (HLD/ETO). Samples were collected from the elevator mechanism and working channel of each duodenoscope and cultured before use. The primary outcome was the proportion of duodenoscopes with an elevator mechanism or working channel culture showing 1 or more MDRO; secondary outcomes included the frequency of duodenoscope contamination with more than 0 and 10 or more colony-forming units (CFU) of aerobic bacterial growth on either sampling location. After 3 months of enrollment, the study was closed because of the futility; we did not observe sufficient events to evaluate the primary outcome. Among 541 duodenoscope culture events, 516 were included in the final analysis. No duodenoscope culture in any group was positive for MDRO. Bacterial growth of more than 0 CFU was noted in 16.1% duodenoscopes in the sHLD group, 16.0% in the dHLD group, and 22.5% in the HLD/ETO group (P = .21). Bacterial growth or 10 or more CFU was noted in 2.3% of duodenoscopes in the sHLD group, 4.1% in the dHLD group, and 4.2% in the HLD/ETO group (P = .36). MRDOs were cultured from 3.2% of pre-procedure rectal swabs and 2.5% of duodenal aspirates. In a comparison of duodenoscopes reprocessed by sHLD, dHLD, or HLD/ETO, we found no significant differences between groups for MDRO or bacteria contamination. Enhanced disinfection methods (dHLD or HLD/ETO) did not provide additional protection against contamination. However, insufficient events occurred to assess our primary study end

  3. Development of integraded mechanistically-based degradation-mode models for performance assessment of high-level waste containers

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J. C., LLNL

    1998-06-01

    A key component of the Engineered Barrier System (EBS) being designed for containment of spent-fuel and high-level waste at the proposed geological repository at Yucca Mountain, Nevada is a two-tayer canister. In this particular design, the inner barrier is made of a corrosion resistant material (CRM) such as Alloy 825, 625 or C-22, while the outer barrier is made of a corrosion-allowance material (CAM) such as A516 Gr 55 or Monel 400. At the present time, Alloy C- 22 and A516 Gr 55 are favored.

  4. High levels of dietary stearate promote adiposity and deteriorate hepatic insulin sensitivity

    Directory of Open Access Journals (Sweden)

    Havekes Louis M

    2010-03-01

    Full Text Available Abstract Background Relatively little is known about the role of specific saturated fatty acids in the development of high fat diet induced obesity and insulin resistance. Here, we have studied the effect of stearate in high fat diets (45% energy as fat on whole body energy metabolism and tissue specific insulin sensitivity. Methods C57Bl/6 mice were fed a low stearate diet based on palm oil or one of two stearate rich diets, one diet based on lard and one diet based on palm oil supplemented with tristearin (to the stearate level of the lard based diet, for a period of 5 weeks. Ad libitum fed Oxidative metabolism was assessed by indirect calorimetry at week 5. Changes in body mass and composition was assessed by DEXA scan analysis. Tissue specific insulin sensitivity was assessed by hyperinsulinemic-euglycemic clamp analysis and Western blot at the end of week 5. Results Indirect calorimetry analysis revealed that high levels of dietary stearate resulted in lower caloric energy expenditure characterized by lower oxidation of fatty acids. In agreement with this metabolic phenotype, mice on the stearate rich diets gained more adipose tissue mass. Whole body and tissue specific insulin sensitivity was assessed by hyperinsulinemic-euglycemic clamp and analysis of insulin induced PKBser473 phosphorylation. Whole body insulin sensitivity was decreased by all high fat diets. However, while insulin-stimulated glucose uptake by peripheral tissues was impaired by all high fat diets, hepatic insulin sensitivity was affected only by the stearate rich diets. This tissue-specific pattern of reduced insulin sensitivity was confirmed by similar impairment in insulin-induced phosphorylation of PKBser473 in both liver and skeletal muscle. Conclusion In C57Bl/6 mice, 5 weeks of a high fat diet rich in stearate induces a metabolic state favoring low oxidative metabolism, increased adiposity and whole body insulin resistance characterized by severe hepatic insulin

  5. Low Power Design with High-Level Power Estimation and Power-Aware Synthesis

    CERN Document Server

    Ahuja, Sumit; Shukla, Sandeep Kumar

    2012-01-01

    Low-power ASIC/FPGA based designs are important due to the need for extended battery life, reduced form factor, and lower packaging and cooling costs for electronic devices. These products require fast turnaround time because of the increasing demand for handheld electronic devices such as cell-phones, PDAs and high performance machines for data centers. To achieve short time to market, design flows must facilitate a much shortened time-to-product requirement. High-level modeling, architectural exploration and direct synthesis of design from high level description enable this design process. This book presents novel research techniques, algorithms,methodologies and experimental results for high level power estimation and power aware high-level synthesis. Readers will learn to apply such techniques to enable design flows resulting in shorter time to market and successful low power ASIC/FPGA design. Integrates power estimation and reduction for high level synthesis, with low-power, high-level design; Shows spec...

  6. Principles for Language Extensions to VHDL to Support High-Level Modeling

    OpenAIRE

    Ashenden, Peter J.; Philip A. Wilsey

    1999-01-01

    This paper reviews proposals for extensions to VHDL to support high-level modeling and places them within a taxonomy that describes the modeling requirements they address. Many of the proposals focus on object-oriented extensions, whereas this paper argues that extension of VHDL to support high-level modeling requires a broader review. The paper presents a detailed discussion of issues to be considered in adding high-level modeling extensions to VHDL, including concurrency and ...

  7. Unique responses of stem cell-derived vascular endothelial and mesenchymal cells to high levels of glucose.

    Directory of Open Access Journals (Sweden)

    Emily Keats

    Full Text Available Diabetes leads to complications in selected organ systems, and vascular endothelial cell (EC dysfunction and loss is the key initiating and perpetuating step in the development of these complications. Experimental and clinical studies have shown that hyperglycemia leads to EC dysfunction in diabetes. Vascular stem cells that give rise to endothelial progenitor cells (EPCs and mesenchymal progenitor cells (MPCs represent an attractive target for cell therapy for diabetic patients. Whether these vascular stem/progenitor cells succumb to the adverse effects of high glucose remains unknown. We sought to determine whether adult vascular stem/progenitor cells display cellular activation and dysfunction upon exposure to high levels of glucose as seen in diabetic complications. Mononuclear cell fraction was prepared from adult blood and bone marrow. EPCs and MPCs were derived, characterized, and exposed to either normal glucose (5 mmol/L or high glucose levels (25 mmol/L. We then assayed for cell activity and molecular changes following both acute and chronic exposure to high glucose. Our results show that high levels of glucose do not alter the derivation of either EPCs or MPCs. The adult blood-derived EPCs were also resistant to the effects of glucose in terms of growth. Acute exposure to high glucose levels increased caspase-3 activity in EPCs (1.4x increase and mature ECs (2.3x increase. Interestingly, MPCs showed a transient reduction in growth upon glucose challenge. Our results also show that glucose skews the differentiation of MPCs towards the adipocyte lineage while suppressing other mesenchymal lineages. In summary, our studies show that EPCs are resistant to the effects of high levels of glucose, even following chronic exposure. The findings further show that hyperglycemia may have detrimental effects on the MPCs, causing reduced growth and altering the differentiation potential.

  8. Fabrication and characterization of Tm3+-Ho3+ co-doped tellurite glass microsphere lasers operating at ∼2.1 μm

    Science.gov (United States)

    Yang, Zhengsheng; Wu, Yuehao; Yang, Kun; Xu, Peipeng; Zhang, Wei; Dai, Shixun; Xu, Tiefeng

    2017-10-01

    We used a Tm3+-Ho3+ co-doped tellurite glass as the laser medium to build active microsphere laser resonators. A droplet method is implemented and hundreds of high quality microspheres can be fabricated simultaneously. Typical Quality factors (Q-factors) of microspheres fabricated in this work reach 106. Silica fiber tapers are used as the coupling mechanism and a commercial 808 nm laser diode is used as the pump source. Laser lines at ∼2.1 μm can be observed in the emission spectrum of these active microsphere resonators. Pump thresholds for generating single mode laser lines in a 59.52 μm diameter microsphere is measured to be 0.887 mW and as the pump power is increased to 1.413 mW, multi-mode laser lines can be generated. We also demonstrate microsphere lasers fabricated in this work can be thermally tuned with a temperature sensitivity of 32 pm/°C, implying these microspheres can be used as highly compact temperature sensors in various mid-infrared applications.

  9. A portable luminescent thermometer based on green up-conversion emission of Er3+/Yb3+ co-doped tellurite glass

    Science.gov (United States)

    Manzani, Danilo; Petruci, João Flávio Da Silveira; Nigoghossian, Karina; Cardoso, Arnaldo Alves; Ribeiro, Sidney J. L.

    2017-01-01

    The determination of temperature is essential in many applications in the biomedical, technological, and industrial fields. Optical thermometry appears to be an excellent alternative for conventional electric temperature sensors because it is a non-contact method that offers a fast response, electromagnetic passivity, and high temperature sensitivity. In this paper, we propose an optical thermometer probe comprising an Er3+/Yb3+ co-doped tellurite glass attached to the tip of an optical fibre and optically coupled to a laser source and a portable USB spectrometer. The ratio of the up-conversion green emission integrated peak areas when excited at 980 nm was temperature dependent, and it was used to calibrate the thermometer. The thermometer was operated in the range of 5-50 °C and 50-200 °C, and it revealed excellent linearity (r2 > 0.99), suitable accuracy, and precisions of ±0.5 and ±1.1 °C, respectively. By optimizing Er3+ concentration, we could obtain the high green emission intensity, and in turn, high thermal sensitivity for the probe. The probe fabricated in the study exhibited suitable properties for its application as a temperature sensor and superior performance compared to other Er3+ -based optical thermometers in terms of thermal sensitivity.

  10. Strong blue emission from Pr3+ ions through energy transfer process from Nd3+ to Pr3+ via Yb3+ in tellurite glass.

    Science.gov (United States)

    Kumar, Kaushal; Rai, S B; Rai, Anita

    2008-11-15

    Energy transfer excited upconversion emission in Nd3+/Pr3+-codped tellurite glass have been studied on pumping with 800 nm wavelength. The upconversion emission bands from Pr3+ ion are observed at the 488, 524, 546, 612, 647, 672, 708 and 723 nm due to the (3P0 + 3P1)-->3H4, 3P1-->3H5, 3P0-->3H5, 3P0-->3H6, 3P0-->3F2, 3P1-->3F3, 3P0-->3F3 and 3P0-->3F4 transitions, respectively. The addition of ytterbium ions (Yb3+) on the upconversion emission intensity is also studied and result shows an eight times enhancement in the upconversion intensity at 488 nm from Pr3+ ions. The pump power and concentration dependence studies are also made. It is found that Yb3+ ions transfer its excitation energy to Nd3+ from which it goes to Pr3+. No direct transfer to Pr3+ is seen. This is verified by codoping Nd3+ and Pr3+ into the host.

  11. Geomicrobiology of High Level Nuclear Waste-Contaminated Vadose Sediments at the Hanford Site, Washington State

    Energy Technology Data Exchange (ETDEWEB)

    Fredrickson, Jim K.; Zachara, John M.; Balkwill, David L.; Kennedy, David W.; Li, Shu-Mei W.; Kostandarithes, Heather M.; Daly, Michael J.; Romine, Margaret F.; Brockman, Fred J.

    2004-07-07

    Sediments from a high-level nuclear waste plume were collected as part of investigations to evaluate the potential fate and migration of contaminants in the subsurface. The plume originated from a leak that occurred in 1962 from a waste tank consisting of high concentrations of alkali, nitrate, aluminate, Cr(VI), 137Cs, and 99Tc. Investigations were initiated to determine the distribution of viable microorganisms in the vadose sediment samples, probe the phylogeny of cultivated and uncultivated members, and evaluate the ability of the cultivated organisms to survive acute doses of ionizing radiation. The populations of viable aerobic heterotrophic bacteria were generally low, from below detection to {approx}104 7 CFU g-1 but viable microorganisms were recovered from 11 of 16 samples including several of the most radioactive ones (e.g., > 10 ?Ci/g 137Cs). The isolates from the contaminated sediments and clone libraries from sediment DNA extracts were dominated by members related to known Gram-positive bacteria. Gram-positive bacteria most closely related to Arthrobacter species were the most common isolates among all samples but other high G+C phyla were also represented including Rhodococcus and Nocardia. Two isolates from the second most radioactive sample (>20 ?Ci 137Cs g-1) were closely related to Deinococcus radiodurans and were able to survive acute doses of ionizing radiation approaching 20kGy. Many of the Gram-positive isolates were resistant to lower levels of gamma radiation. These results demonstrate that Gram-positive bacteria, predominantly high G+C phyla, are indigenous to Hanford vadose sediments and some are effective at surviving the extreme physical and chemical stress associated with radioactive waste.

  12. Survey of degradation modes of candidate materials for high-level radioactive-waste disposal containers

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J.C.; Van Konynenburg, R.A.; McCright, R.D. (Lawrence Livermore National Lab., CA (USA)); Gdowski, G.E. (Science and Engineering Associates, Inc., Pleasanton, CA (USA))

    1988-06-01

    Three copper-based alloys, CDA 102 (oxygen-free, high-purity copper), CDA 613 (aluminum bronze), and CDA 715 (Cu-30Ni), are candidates for the fabrication of high-level radioactive-waste disposal containers. Waste will include spent fuel assemblies from reactors as well as borosilicate glass, and will be sent to the prospective repository site at Yucca Mountain in Nye County, Nevada. The decay of radionuclides will result in the generation of substantial heat and in fluxes of gamma radiation outside the containers. In this environment, container materials might degrade by atmospheric oxidation, general aqueous phase corrosion, localized corrosion (LC), and stress corrosion cracking (SCC). This volume is a critical survey of available data on pitting and crevice corrosion of the copper-based candidates. Pitting and crevice corrosion are two of the most common forms of LC of these materials. Data on the SCC of these alloys is surveyed in Volume 4. Pitting usually occurs in water that contains low concentrations of bicarbonate and chloride anions, such as water from Well J-13 at the Nevada Test Site. Consequently, this mode of degradation might occur in the repository environment. Though few quantitative data on LC were found, a tentative ranking based on pitting corrosion, local dealloying, crevice corrosion, and biofouling is presented. CDA 102 performs well in the categories of pitting corrosion, local dealloying, and biofouling, but susceptibility to crevice corrosion diminishes its attractiveness as a candidate. The cupronickel alloy, CDA 715, probably has the best overall resistance to such localized forms of attack. 123 refs., 11 figs., 3 tabs.

  13. Hi-LAB: A New Measure of Aptitude for High-Level Language Proficiency

    Science.gov (United States)

    Linck, Jared A.; Hughes, Meredith M.; Campbell, Susan G.; Silbert, Noah H.; Tare, Medha; Jackson, Scott R.; Smith, Benjamin K.; Bunting, Michael F.; Doughty, Catherine J.

    2013-01-01

    Few adult second language (L2) learners successfully attain high-level proficiency. Although decades of research on beginning to intermediate stages of L2 learning have identified a number of predictors of the rate of acquisition, little research has examined factors relevant to predicting very high levels of L2 proficiency. The current study,…

  14. Requirements for high level models supporting design space exploration in model-based systems engineering

    NARCIS (Netherlands)

    Haveman, Steven; Bonnema, Gerrit Maarten

    2013-01-01

    Most formal models are used in detailed design and focus on a single domain. Few effective approaches exist that can effectively tie these lower level models to a high level system model during design space exploration. This complicates the validation of high level system requirements during

  15. New vanadium tellurites: Syntheses, structures, optical properties of noncentrosymmetric VTeO{sub 4}(OH), centrosymmetric Ba{sub 2}V{sub 4}O{sub 8}(Te{sub 3}O{sub 10})

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Ming-Li [College of Chemistry, Fuzhou University, Fuzhou, Fujian 350108 (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Marsh, Matthew [Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306 (United States); Shang, Xian-Xing [College of Chemistry, Fuzhou University, Fuzhou, Fujian 350108 (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Mao, Jiang-Gao [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Albrecht-Schmitt, Thomas E. [Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306 (United States); Kong, Fang, E-mail: kongfang@fjirsm.ac.cn [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306 (United States)

    2017-05-15

    Two new vanadium tellurites, VTeO{sub 4}(OH) (1) and Ba{sub 2}V{sub 4}O{sub 8}(Te{sub 3}O{sub 10}) (2), have been synthesized successfully with the use of hydrothermal reactions. The crystal structures of the two compounds were determined by single-crystal X-ray diffraction. Compound 1 crystallizes in the polar space group Pca2{sub 1} (No. 29) while compound 2 crystallizes in the centrosymmetric space group C2/c (No. 15). The topography of compound 1 reveals a two-dimensional, layered structure comprised of VO{sub 6} octahedral chains and TeO{sub 3}(OH) zig-zag chains. Compound 2, on the contrary, features a three-dimensional [V{sub 4}O{sub 8}(Te{sub 3}O{sub 10})]{sup 4-} anionic framework with Ba{sup 2+} ions filled into the 10-member ring helical tunnels. The [V{sub 4}O{sub 8}(Te{sub 3}O{sub 10})]{sup 4-} anionic network is the first 3D vanadium tellurite framework to be discovered in the alkaline-earth vanadium tellurite system. Powder second harmonic generation (SHG) measurements indicate that compound 1 shows a weak SHG response of about 0.3×KDP (KH{sub 2}PO{sub 4}) under 1064 nm laser radiation. Infrared spectroscopy, elemental analysis, thermal analysis, and dipole moment calculations have also been carried out. - Graphical abstract: VTeO{sub 4}(OH) (1) crystallizes in the noncentrosymmetric space group Pca2{sub 1} (No. 29) while Ba{sub 2}V{sub 4}O{sub 8}(Te{sub 3}O{sub 10}) (2) crystallizes in the centrosymmetric space group C2/c (No. 15). - Highlights: • VTeO{sub 4}(OH) (1) and Ba{sub 2}V{sub 4}O{sub 8}(Te{sub 3}O{sub 10}) (2) have been synthesized successfully with the use of hydrothermal reactions. • VTeO{sub 4}(OH) (1) crystallizes in the noncentrosymmetric space group Pca2{sub 1} and displays a weak SHG response. • VTeO{sub 4}(OH) (1) represents only the fourth SHG-active material found in vanadium tellurite systems. • Ba{sub 2}V{sub 4}O{sub 8}(Te{sub 3}O{sub 10}) (2) exhibits a novel three-dimensional [V{sub 4}O{sub 8}(Te{sub 3}O{sub 10

  16. High-level mobility outcomes following acquired brain injury: a preliminary evaluation.

    Science.gov (United States)

    Williams, Gavin P; Morris, Meg E

    2009-04-01

    To evaluate the efficacy of a high-level mobility programme for people with acquired brain injury (ABI). A cohort study which evaluated the efficacy of a high-level mobility programme for people with ABI. A major rehabilitation hospital. Twenty-eight people with acquired brain injury. A 3 month high-level mobility programme conducted twice weekly consisting of strengthening exercises, pre-running and running drills and agility exercises supplemented with a gym or home exercise programme. The primary outcome measure was the high-level mobility assessment tool (HiMAT). Participants were predominantly male and young (average age 33.2 years, range 16-72 years) with chronic ABI. HiMAT scores for the 28 participants who returned at the 3 month follow-up initially ranged from 6-44 points (mean 20.3). The 3 month follow-up scores ranged from 12-51 points (mean 29.2). The mean HiMAT score change ranged from 2-20 points (mean 8.9). Significant recovery in high-level mobility was achieved during a 3 month running programme. People with chronic ABI may also expect to benefit from retraining high-level mobility. Clinical trials are needed to assess the effectiveness of training programmes for high-level mobility.

  17. Demonstration of Caustic-Side Solvent Extraction with Savannah River Site High Level Waste

    Energy Technology Data Exchange (ETDEWEB)

    Walker, D.D.

    2001-08-27

    Researchers successfully demonstrated the chemistry and process equipment of the Caustic-Side Solvent Extraction (CSSX) flowsheet for the decontamination of high level waste using a 33-stage, 2-cm centrifugal contactor apparatus at the Savannah River Technology Center. This represents the first CSSX process demonstration using Savannah River Site (SRS) high level waste. Three tests lasting 6, 12, and 48 hours processed simulated average SRS waste, simulated Tank 37H/44F composite waste, and Tank 37H/44F high level waste, respectively.

  18. A framework for the definition of variants of high-level Petri nets

    DEFF Research Database (Denmark)

    Kindler, Ekkart; Petrucci, Laure

    2009-01-01

    with data-type specific issues, which often blocks the view for the really relevant parts. Even worse, supposedly simpler versions of high-level nets often are more difficult to define than high-level nets in general. This paper introduces the concepts and the mathematical tools to ease the definition...... analysis algorithms for symmetric nets. During the standardisation of high-level nets and some of their variations, it turned out that defining the legal data types and the operations on them is the most difficult part. In particular, these definitions become lengthy and mix Petri net specific issues...

  19. Analysis of the lack of scientific and technological talents of high-level women in China

    Science.gov (United States)

    Lin, Wang

    2017-08-01

    The growth and development of high-level female scientific and technological talents has become a global problem, facing severe challenges. The lack of high-level women in science and technology has become a global problem. How to recruit and help female scientists and technological talents grow raises awareness from the industry. To find out the main reasons for the lack of high-level female scientific and technological talent. This paper analyses the impact of gender discrimination on the lack of high-level female scientific and technological talents, the impact of disciplinary differences on female roles. The main reasons are: women’s natural disadvantage of mathematical thinking; female birth, the traditional culture on the role of women and the impact of values.

  20. Advanced Distributed Simulation Technology II (ADST II) High Level Architecture Support Experiments

    National Research Council Canada - National Science Library

    1998-01-01

    The purpose of the High Level Architecture (HLA) Support Experiments (HSE) project was to perform experimentation and research in HLA technology to support the evolution and further implementation of the HLA specifications...

  1. Demonstration of Small Tank Tetraphenylborate Precipitation Process Using Savannah River Site High Level Waste

    Energy Technology Data Exchange (ETDEWEB)

    Peters, T.B.

    2001-09-10

    This report details the experimental effort to demonstrate the continuous precipitation of cesium from Savannah River Site High Level Waste using sodium tetraphenylborate. In addition, the experiments examined the removal of strontium and various actinides through addition of monosodium titanate.

  2. Frameworks to monitor and predict rates and resource usage in the ATLAS High Level Trigger

    Science.gov (United States)

    Martin, Tim; ATLAS Collaboration

    2017-10-01

    The ATLAS High Level Trigger Farm consists of around 40,000 CPU cores which filter events at an input rate of up to 100 kHz. A costing framework is built into the high level trigger thus enabling detailed monitoring of the system and allowing for data-driven predictions to be made utilising specialist datasets. An overview is presented in to how ATLAS collects in-situ monitoring data on CPU usage during the trigger execution, and how these data are processed to yield both low level monitoring of individual selection-algorithms and high level data on the overall performance of the farm. For development and prediction purposes, ATLAS uses a special ‘Enhanced Bias’ event selection. This mechanism is explained along with how it is used to profile expected resource usage and output event rate of new physics selections, before they are executed on the actual high level trigger farm.

  3. Frameworks to monitor and predict rates and resource usage in the ATLAS High Level Trigger

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00219969; The ATLAS collaboration

    2016-01-01

    The ATLAS High Level Trigger Farm consists of around 40,000 CPU cores which filter events at an input rate of up to 100 kHz. A costing framework is built into the high level trigger thus enabling detailed monitoring of the system and allowing for data-driven predictions to be made utilising specialist datasets. An overview is presented in to how ATLAS collects in-situ monitoring data on CPU usage during the trigger execution, and how these data are processed to yield both low level monitoring of individual selection-algorithms and high level data on the overall performance of the farm. For development and prediction purposes, ATLAS uses a special ‘Enhanced Bias’ event selection. This mechanism is explained along with how it is used to profile expected resource usage and output event rate of new physics selections, before they are executed on the actual high level trigger farm.

  4. Virological profile of pregnant HIV positive women with high levels of ...

    African Journals Online (AJOL)

    Virological profile of pregnant HIV positive women with high levels of CD4 count in low income settings: Can viral load help as eligibility criteria for maternal triple ARV prophylaxis (WHO 2010 option B)?

  5. Anthropometric and fitness profile of high-level basketball, handball and volleyball players

    Directory of Open Access Journals (Sweden)

    J. Peña

    2018-01-01

    Conclusions: There is evidence of anthropometric and physiological differences among the high-level team sports analyzed. Its assessment seems capital for the improvement of training strategies and accurate talent identification processes.

  6. Factors related to high-level mobility in male servicemembers with traumatic lower-limb loss

    OpenAIRE

    Ignacio A. Gaunaurd, PhD, MSPT; Kathryn E. Roach, PhD, PT; Michele A. Raya, PhD, PT, SCS, ATC; COL (Ret) Rebecca Hooper, PhD, PT; Alison A. Linberg, DPT, ATC; Justin Z. Laferrier, PhD, MSPT, OCS, SCS, ATP, CSCS; MAJ (Ret) Stuart M. Campbell, MPT; COL (Ret) Charles Scoville, PT, DPT; Robert S. Gailey, PhD, PT

    2013-01-01

    The purpose of this study was to examine the possible relationship between factors modifiable by rehabilitation interventions (rehabilitation factors), other factors related to lower-limb loss (other factors), and high-level mobility as measured by the Comprehensive High-Level Activity Mobility Predictor (CHAMP) in servicemembers (SMs) with traumatic lower-limb loss. One-hundred eighteen male SMs with either unilateral transtibial amputation (TTA), unilateral transfemoral amputation (TFA), or...

  7. Research and development on geological disposal of high-level radioactive waste; First progress report

    OpenAIRE

    1992-01-01

    The "first progress report of research and development ongeological disposal of high level radioactive waste", h3 in short, isintended for the japanese authorities. In accordance with the "overallprogram for high level radioactive waste management" set forth byatomic energy commission, h3 is designed to clarify the current status ofthe research and development work performed by power reactor and nuclearfuel development corporation(pnc) up to the year 1991. H3 presents the updated knowledge on...

  8. H-3 Summary report research and development on geolgical disposal of high-level radioactive waste

    OpenAIRE

    1992-01-01

    The "First progress report of research and development ongeological disposal of high level radioactive waste",H3 in short,is intended for the Japanese authorities. In accordance with the "Overall program for high level radioactive waste management" set forth by atomic energy commission, H3 is designed to clarify the current status of the research and development work performed by power reactor and nuclear fuel development corporation (PNC) up to the year 1991. H3 presents the updated knowledg...

  9. High-level heterologous expression and properties of a novel lipase from Ralstonia sp. M1.

    Science.gov (United States)

    Quyen, Dinh Thi; Giang Le, Thi Thu; Nguyen, Thi Thao; Oh, Tae-Kwang; Lee, Jung-Kee

    2005-01-01

    The mature lipase LipA and its 56aa-truncated chaperone DeltaLipBhis (with 6xhis-tag) from Ralstonia sp. M1 were over-expressed in Escherichia coli BL21 under the control of T7 promoter with a high level of 70 and 12mg protein per gram of wet cells, respectively. The simply purified lipase LipA was effectively refolded by Ni-NTA purified chaperone DeltaLipBhis in molar ratio 1:1 at 4 degrees C for 24 hours in H2O. The in vitro refolded lipase LipA had an optimal activity in the temperature range of 50-55 degrees C and was stable up to 45 degrees C with more than 84% activity retention. The maximal activity was observed at pH 10.75 for hydrolysis of olive oil and found to be stable over alkaline pH range 8.0-10.5 with more than 52% activity retention. The enzyme was found to be highly resistant to many organic solvents especially induced by ethanolamine (remaining activity 137-334%), but inhibited by 1-butanol and acetonitrile (40-86%). Metal ions Cu2+, Sn2+, Mn2+, Mg2+, and Ca2+ stimulated the lipase slightly with increase in activity by up to 22%, whereas Zn2+ significantly inhibited the enzyme with the residual activity of 30-65% and Fe3+ to a lesser degree (activity retention of 77-86%). Tween 80, Tween 60, and Tween 40 induced the activation of the lipase LipA (222-330%) and 0.2-1% (w/v) of Triton X-100, X-45, and SDS increased the lipase activity by up to 52%. However, 5% (w/v) of Triton X-100, X-45, and SDS inhibited strongly the activity by 31-89%. The inhibitors including DEPC, EDTA, PMSF, and 2-mercaptoethanol (0.1-10mM) inhibited moderately the lipase with remaining activity of 57-105%. The lipase LipA hydrolyzed a wide range of triglycerides, but preferentially short length acyl chains (C4 and C6). In contrast to the triglycerides, medium length acyl chains (C8 and C14) of p-nitrophenyl (p-NP) esters were preferential substrates of this lipase. The enzyme preferentially catalyzed the hydrolysis of cottonseed oil (317%), cornoil (227%), palm oil (222

  10. Hydrothermal synthesis and characterization of two new layered vanadium tellurites Cu(TATP)V 2TeO 8 and Cu(DPPZ)V 2Te 2O 10

    Science.gov (United States)

    Han, Guang-Xi; Song, Yong-Juan; Han, Zheng-Bo

    2009-08-01

    Two new vanadium tellurites, Cu(TATP)V 2TeO 8(1) and Cu(DPPZ)V 2Te 2O 10(2), (TATP=1,4,8,9-tetranitrogen-trisphene, DPPZ=dipyridophenazine) have been synthesized under hydrothermal conditions and structurally characterized by elemental analyses, IR, and single-crystal X-ray diffraction. Compound 1 features an interesting two-dimensional layer structure constructed by [V 2TeO 8] n double-chain-like ribbons linked by [Cu(TATP)] 2+ bridges. Compound 2 consists of two types of chiral layers: one left-handed and the other right-handed, which lead to racemic solid-state compound. In each layer, there exist two types of inorganic helical chains (V 4Te 4O 8) n and (Te 2O 2) n, with same handedness. Two types of helical chains are linked by μ3(O6) atoms to generate a V/Te/O inorganic anionic layer. The [Cu(DPPZ)] 2+ cationic complex fragments are covalently bonded to the layer, projecting below and above the vanadium tellurites layer.

  11. Single- and double energy N{sup +} ion irradiated planar optical waveguides in Er: Tungsten–tellurite oxide glass and sillenite type Bismuth Germanate crystals working up to telecommunications wavelengths

    Energy Technology Data Exchange (ETDEWEB)

    Bányász, I., E-mail: banyasz@sunserv.kfki.hu [Department of Crystal Physics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Zolnai, Z.; Fried, M.; Lohner, T. [Research Institute for Technical Physics and Materials Science, Research Centre for Natural Sciences, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Berneschi, S.; Righini, G.C. [MDF-Lab, “Nello Carrara” Institute of Applied Physics, IFAC-CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); “Enrico Fermi” Center for Study and Research, Piazza del Viminale 2, 00184 Roma (Italy); Pelli, S.; Nunzi-Conti, G. [MDF-Lab, “Nello Carrara” Institute of Applied Physics, IFAC-CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy)

    2013-07-15

    Ion implantation proved to be a universal technique for producing waveguides in most optical materials. Tellurite glasses are good hosts of rare-earth elements for the development of fibre and integrated optical amplifiers and lasers covering all the main telecommunication bands. Er{sup 3+}-doped tellurite glasses are good candidates for the fabrication of broadband amplifiers in wavelength division multiplexing around 1.55 μm, as they exhibit large stimulated cross sections and broad emission bandwidth. Fabrication of channel waveguides in such a material via N{sup +} ion implantation was reported recently. Sillenite type Bismuth Germanate (BGO) crystals are good nonlinear optical materials. Parameters of waveguide fabrication in both materials via implantation of MeV-energy N{sup +} ions were optimized. First single-energy implantations at 3.5 MeV at various fluences were applied. Waveguide operation up to 1.5 μm was observed in both materials. Then double-energy implantations at a fixed upper energy of 3.5 MeV and lower energies between 2.5 and 3.1 MeV were performed to suppress leaky modes by increasing barrier width. Improvement of waveguide characteristics was found by m-line spectroscopy and spectroscopic ellipsometry.

  12. Rapid high-level production of functional HIV broadly neutralizing monoclonal antibodies in transient plant expression systems.

    Directory of Open Access Journals (Sweden)

    Yvonne Rosenberg

    Full Text Available Passive immunotherapy using anti-HIV broadly neutralizing monoclonal antibodies (mAbs has shown promise as an HIV treatment, reducing mother-to-child-transmission (MTCT of simian/human immunodeficiency virus (SHIV in non-human primates and decreasing viral rebound in patients who ceased receiving anti-viral drugs. In addition, a cocktail of potent mAbs may be useful as mucosal microbicides and provide an effective therapy for post-exposure prophylaxis. However, even highly neutralizing HIV mAbs used today may lose their effectiveness if resistance occurs, requiring the rapid production of new or engineered mAbs on an ongoing basis in order to counteract the viral resistance or the spread of a certain HIV-1 clade in a particular region or patient. Plant-based expression systems are fast, inexpensive and scalable and are becoming increasingly popular for the production of proteins and monoclonal antibodies. In the present study, Agrobacterium-mediated transient transfection of plants, utilizing two species of Nicotiana, have been tested to rapidly produce high levels of an HIV 89.6PΔ140env and several well-studied anti-HIV neutralizing monoclonal antibodies (b12, 2G12, 2F5, 4E10, m43, VRC01 or a single chain antibody construct (m9, for evaluation in cell-based viral inhibition assays. The protein-A purified plant-derived antibodies were intact, efficiently bound HIV envelope, and were equivalent to, or in one case better than, their counterparts produced in mammalian CHO or HEK-293 cells in both neutralization and antibody dependent viral inhibition assays. These data indicate that transient plant-based transient expression systems are very adaptable and could rapidly generate high levels of newly identified functional recombinant HIV neutralizing antibodies when required. In addition, they warrant detailed cost-benefit analysis of prolonged incubation in plants to further increase mAb production.

  13. Rapid high-level production of functional HIV broadly neutralizing monoclonal antibodies in transient plant expression systems.

    Science.gov (United States)

    Rosenberg, Yvonne; Sack, Markus; Montefiori, David; Forthal, Donald; Mao, Lingjun; Hernandez-Abanto, Segundo; Urban, Lori; Landucci, Gary; Fischer, Rainer; Jiang, Xiaoming

    2013-01-01

    Passive immunotherapy using anti-HIV broadly neutralizing monoclonal antibodies (mAbs) has shown promise as an HIV treatment, reducing mother-to-child-transmission (MTCT) of simian/human immunodeficiency virus (SHIV) in non-human primates and decreasing viral rebound in patients who ceased receiving anti-viral drugs. In addition, a cocktail of potent mAbs may be useful as mucosal microbicides and provide an effective therapy for post-exposure prophylaxis. However, even highly neutralizing HIV mAbs used today may lose their effectiveness if resistance occurs, requiring the rapid production of new or engineered mAbs on an ongoing basis in order to counteract the viral resistance or the spread of a certain HIV-1 clade in a particular region or patient. Plant-based expression systems are fast, inexpensive and scalable and are becoming increasingly popular for the production of proteins and monoclonal antibodies. In the present study, Agrobacterium-mediated transient transfection of plants, utilizing two species of Nicotiana, have been tested to rapidly produce high levels of an HIV 89.6PΔ140env and several well-studied anti-HIV neutralizing monoclonal antibodies (b12, 2G12, 2F5, 4E10, m43, VRC01) or a single chain antibody construct (m9), for evaluation in cell-based viral inhibition assays. The protein-A purified plant-derived antibodies were intact, efficiently bound HIV envelope, and were equivalent to, or in one case better than, their counterparts produced in mammalian CHO or HEK-293 cells in both neutralization and antibody dependent viral inhibition assays. These data indicate that transient plant-based transient expression systems are very adaptable and could rapidly generate high levels of newly identified functional recombinant HIV neutralizing antibodies when required. In addition, they warrant detailed cost-benefit analysis of prolonged incubation in plants to further increase mAb production.

  14. Laboratory selection for spirodiclofen resistance and cross ...

    African Journals Online (AJOL)

    Selection for spirodiclofen resistance was done in the laboratory with a susceptible strain of the citrus red mite, Panonychus citri (McGregor). Successive selections for spirodiclofen resistance through 42 generations resulted in a high level of resistance and the resistance ratio at LC50 was 103 compared with that of the ...

  15. Laboratory selection for spirodiclofen resistance and cross ...

    African Journals Online (AJOL)

    Administrator

    2011-04-25

    Apr 25, 2011 ... Selection for spirodiclofen resistance was done in the laboratory with a susceptible strain of the citrus red mite, Panonychus citri (McGregor). Successive selections for spirodiclofen resistance through 42 generations resulted in a high level of resistance and the resistance ratio at LC50 was 103 compared.

  16. Development of a test system for high level liquid waste partitioning

    Directory of Open Access Journals (Sweden)

    Duan Wu H.

    2015-01-01

    Full Text Available The partitioning and transmutation strategy has increasingly attracted interest for the safe treatment and disposal of high level liquid waste, in which the partitioning of high level liquid waste is one of the critical technical issues. An improved total partitioning process, including a tri-alkylphosphine oxide process for the removal of actinides, a crown ether strontium extraction process for the removal of strontium, and a calixcrown ether cesium extraction process for the removal of cesium, has been developed to treat Chinese high level liquid waste. A test system containing 72-stage 10-mm-diam annular centrifugal contactors, a remote sampling system, a rotor speed acquisition-monitoring system, a feeding system, and a video camera-surveillance system was successfully developed to carry out the hot test for verifying the improved total partitioning process. The test system has been successfully used in a 160 hour hot test using genuine high level liquid waste. During the hot test, the test system was stable, which demonstrated it was reliable for the hot test of the high level liquid waste partitioning.

  17. Factors related to high-level mobility in male servicemembers with traumatic lower-limb loss.

    Science.gov (United States)

    Gaunaurd, Ignacio A; Roach, Kathryn E; Raya, Michele A; Hooper, Rebecca; Linberg, Alison A; Laferrier, Justin Z; Campbell, Stuart M; Scoville, Charles; Gailey, Robert S

    2013-01-01

    The purpose of this study was to examine the possible relationship between factors modifiable by rehabilitation interventions (rehabilitation factors), other factors related to lower-limb loss (other factors), and high-level mobility as measured by the Comprehensive High-Level Activity Mobility Predictor (CHAMP) in servicemembers (SMs) with traumatic lower-limb loss. One-hundred eighteen male SMs with either unilateral transtibial amputation (TTA), unilateral transfemoral amputation (TFA), or bilateral lower-limb amputation (BLLA) participated. Stepwise regression analysis was used to develop separate regression models of factors predicting CHAMP score. Regression models containing both rehabilitation factors and other factors explained 81% (TTA), 36% (TFA), and 91% (BLLA) of the variance in CHAMP score. Rehabilitation factors such as lower-limb strength and dynamic balance were found to be significantly related to CHAMP score and can be enhanced with the appropriate intervention. Further, the findings support the importance of salvaging the knee joint and its effect on high-level mobility capabilities. Lastly, the J-shaped energy storage and return feet were found to improve high-level mobility for SMs with TTA. These results could help guide rehabilitation and aid in developing appropriate interventions to assist in maximizing high-level mobility capabilities for SMs with traumatic lower-limb loss.

  18. High-level synthesis for reduction of WCET in real-time systems

    DEFF Research Database (Denmark)

    Kristensen, Andreas Toftegaard; Pezzarossa, Luca; Sparsø, Jens

    2017-01-01

    The increasing design complexity of systems-on-chip (SoCs) requires designers to work at higher levels of abstraction. High-level synthesis (HLS) is one approach towards this. It allows designers to synthesize hardware directly from code written in a high-level programming language and to more...... quickly explore alternative implementations by re-running the synthesis with different optimization parameters and pragmas. HLS is particularly interesting for FPGA circuits, where different hardware implementations can easily be loaded into the target device. Another perspective on HLS is performance....... Compared to executing the high-level language code on a processor, HLS can be used to create hardware that accelerates critical parts of the code. When discussing performance in the context or real-time systems, it is the worst-case execution time (WCET) of a task that matters. WCET obviously benefits from...

  19. THE APPLICATION OF FEATURE TECHNOLOGY IN DEVELOPING A CAD-BASED HIGH LEVEL PROCESS PLANNING SYSTEM

    Directory of Open Access Journals (Sweden)

    Ade Febransyah

    2005-01-01

    Full Text Available High-level process planning plays an important role in determining candidate process domains at the configuration design stage. Changing the process domains later increases the product development cycle and the product development cost. Therefore, determining the most appropriate manufacturing processes at the beginning stages of the design process becomes critical. However, high-level process planning systems have traditionally lacked integration of design synthesis and design evaluation. The objective of this paper is to propose a CAD-based high-level process planning system that will help designers decide whether or not the designs are worth pursuing. A hybrid approach incorporating design by feature and feature recognition approaches is proposed and implemented. Synergizing both advantages of both approaches will reduce the complexity of feature recognition algorithm without sacrificing the flexibility in creating a part model.

  20. [Detraining and retraining after injury in a high-level cyclist].

    Science.gov (United States)

    Dauty, M; Louvet, S; Potiron-Josse, M; Dubois, C

    2005-03-01

    To define retraining after injury in a high-level cyclist by taking into account the consequences of detraining. From three clinical cases and from the analysis of the consequences of detraining, three principles of retraining were determined. 1. The high-level cyclist is not protected and loses cycling capacity after four weeks of inactivity. The delay in recovery is longer the higher the adaptations. 2. Recovery of cycling capacity is based on bicycle exercises that are greater in intensity than quantity, taking into account delays in injury consolidation. 3. Retraining requires appreciating the individual physiological level by evaluating force and endurance before envisaging the resumption of training and competition. The injury of a high-level cyclist is at the origin of detraining, which has been evaluated so that sports rehabilitation may enable the cyclist to find a previous state without relapse, complication or overtraining.

  1. Phase I high-level waste pretreatment and feed staging plan

    Energy Technology Data Exchange (ETDEWEB)

    Manuel, A.F.

    1996-02-05

    This document provides the preliminary planning basis for the U.S. Department of Energy (DOE) to provide a sufficient quantity of high-level waste feed to the privatization contractor during Phase I. By this analysis of candidate high-level waste feed sources, the initial quantity of high-level waste feed totals more than twice the minimum feed requirements. The flexibility of the current infrastructure within tank farms provides a variety of methods to transfer the feed to the privatization contractor`s site location. The amount and type of pretreatment (sludge washing) necessary for the Phase I processing can be tailored to support the demonstration goals without having a significant impact on glass volume (i.e., either inhibited water or caustic leaching can be used).

  2. Representation and Integration: Combining Robot Control, High-Level Planning, and Action Learning

    DEFF Research Database (Denmark)

    Petrick, Ronald; Kraft, Dirk; Mourao, Kira

    We describe an approach to integrated robot control, high-level planning, and action effect learning that attempts to overcome the representational difficulties that exist between these diverse areas. Our approach combines ideas from robot vision, knowledgelevel planning, and connectionist machine...... learning, and focuses on the representational needs of these components.We also make use of a simple representational unit called an instantiated state transition fragment (ISTF) and a related structure called an object-action complex (OAC). The goal of this work is a general approach for inducing high......-level action specifications, suitable for planning, from a robot’s interactions with the world. We present a detailed overview of our approach and show how it supports the learning of certain aspects of a high-level lepresentation from low-level world state information....

  3. Predictors of High Level of Hostility among Homeless Men on Parole.

    Science.gov (United States)

    Nyamathi, Adeline; Salem, Benissa; Farabee, David; Hall, Elizabeth; Zhang, Sheldon; Khalilifard, Farinaz; Faucette, Mark; Leake, Barbara

    2014-02-01

    High levels of hostility present a formidable challenge among homeless ex-offenders. This cross-sectional study assessed correlates of high levels of hostility using baseline data collected on recently-released male parolees (N=472; age 18-60) participating in a randomized trial focused on prevention of illicit drug use and recidivism. Predictors of high levels of hostility included greater depressive symptomatology, lower self-esteem, having a mother who was treated for alcohol/drugs, belonging to a gang, more tangible support, having used methamphetamine and having a history of cognitive difficulties. These findings highlight the need to understand predictors of hostility among recently released homeless men and how these predictors may relate to recidivism. Research implications are discussed as these findings will shape future nurse-led harm reduction and community-based interventions.

  4. A High-Level Language for Modeling Algorithms and Their Properties

    Science.gov (United States)

    Akhtar, Sabina; Merz, Stephan; Quinson, Martin

    Designers of concurrent and distributed algorithms usually express them using pseudo-code. In contrast, most verification techniques are based on more mathematically-oriented formalisms such as state transition systems. This conceptual gap contributes to hinder the use of formal verification techniques. Leslie Lamport introduced PlusCal, a high-level algorithmic language that has the "look and feel" of pseudo-code, but is equipped with a precise semantics and includes a high-level expression language based on set theory. PlusCal models can be compiled to TLA + and verified using the model checker tlc.

  5. High Level Expression and Purification of Atl, the Major Autolytic Protein of Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Vineet K. Singh

    2014-01-01

    Full Text Available Staphylococcus aureus is a major human and animal pathogen. Autolysins regulate the growth, turnover, cell lysis, biofilm formation, and the pathogenicity of S. aureus. Atl is the major autolysin in S. aureus. The biochemical and structural studies of staphylococcal Atl have been limited due to difficulty in cloning, high level overexpression, and purification of this protein. This study describes successful cloning, high level over-expression, and purification of two forms of fully functional Atl proteins. These pure proteins can be used to study the functional and structural properties of this important protein.

  6. SymexTRON: Symbolic Execution of High-Level Transformation Languages

    DEFF Research Database (Denmark)

    Al-Sibahi, Ahmad Salim; Dimovski, Aleksandar; Wasowski, Andrzej

    2016-01-01

    Transformations form an important part of developing domain specific languages, where they are used to provide semantics for typing and evaluation. Yet, few solutions exist for verifying transformations written in expressive high-level transformation languages. We take a step towards that goal......, by developing a general symbolic execution technique that handles programs written in these high-level transformation languages. We use logical constraints to describe structured symbolic values, including containment, acyclicity, simple unordered collections (sets) and to handle deep type-based querying...

  7. Adapting high-level language programs for parallel processing using data flow

    Science.gov (United States)

    Standley, Hilda M.

    1988-01-01

    EASY-FLOW, a very high-level data flow language, is introduced for the purpose of adapting programs written in a conventional high-level language to a parallel environment. The level of parallelism provided is of the large-grained variety in which parallel activities take place between subprograms or processes. A program written in EASY-FLOW is a set of subprogram calls as units, structured by iteration, branching, and distribution constructs. A data flow graph may be deduced from an EASY-FLOW program.

  8. Insect cell transformation vectors that support high level expression and promoter assessment in insect cell culture

    Science.gov (United States)

    A somatic transformation vector, pDP9, was constructed that provides a simplified means of producing permanently transformed cultured insect cells that support high levels of protein expression of foreign genes. The pDP9 plasmid vector incorporates DNA sequences from the Junonia coenia densovirus th...

  9. Features of Self-Realization in Students with High Level of Persistence

    Directory of Open Access Journals (Sweden)

    S I Kudinov

    2014-12-01

    Full Text Available The results of the empirical research of personality self-realisation in students with a high level of persistence are discussed in the article. The certain characteristics of self-realisation, the dominant sphere and the structure of the phenomenon in question are considered.

  10. Sustainability of High-Level Isolation Capabilities among US Ebola Treatment Centers.

    Science.gov (United States)

    Herstein, Jocelyn J; Biddinger, Paul D; Gibbs, Shawn G; Le, Aurora B; Jelden, Katelyn C; Hewlett, Angela L; Lowe, John J

    2017-06-01

    To identify barriers to maintaining and applying capabilities of US high-level isolation units (HLIUs) used during the Ebola virus disease outbreak, during 2016 we surveyed HLIUs. HLIUs identified sustainability challenges and reported the highly infectious diseases they would treat. HLIUs expended substantial resources in development but must strategize models of sustainability to maintain readiness.

  11. Advanced Inverter Functions to Support High Levels of Distributed Solar: Policy and Regulatory Considerations (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2014-11-01

    This paper explains how advanced inverter functions (sometimes called 'smart inverters') contribute to the integration of high levels of solar PV generation onto the electrical grid and covers the contributions of advanced functions to maintaining grid stability. Policy and regulatory considerations associated with the deployment of advanced inverter functions are also introduced.

  12. DSC of Milk Fats from Various Animals with High Levels of Medium ...

    African Journals Online (AJOL)

    NICO

    DSC of Milk Fats from Various Animals with High Levels of. Medium-Chain, Unsaturated and Polyunsaturated. Fatty Acids. Gernot Osthoffa,*, Arno Hugoa, Chris C. Joubertb and Jannie C. Swartsb. aDepartment of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa.

  13. Long-term performance and behavior of sows fed high levels of non-starch polysaccharides

    NARCIS (Netherlands)

    Peet-Schwering, van der C.M.C.

    2004-01-01

    The main objective of this thesis was to investigate the long-term effects of feeding sows high levels of dietary fermentable non-starch polysaccharides CNSP) (i.e., NSP from sugar beet pulp) restrictedly or ad libitum during gestation or ad libitum during lactation on behavior, reproductive

  14. Chem I Supplement. Chemistry Related to Isolation of High-Level Nuclear Waste.

    Science.gov (United States)

    Hoffman, Darleane C.; Choppin, Gregory R.

    1986-01-01

    Discusses some of the problems associated with the safe disposal of high-level nuclear wastes. Describes several waste disposal plans developed by various nations. Outlines the multiple-barrier concept of isolation in deep geological questions associated with the implementation of such a method. (TW)

  15. 75 FR 61228 - Board Meeting: Technical Lessons Gained From High-Level Nuclear Waste Disposal Efforts

    Science.gov (United States)

    2010-10-04

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR WASTE TECHNICAL REVIEW BOARD Board Meeting: Technical Lessons Gained From High-Level Nuclear Waste Disposal Efforts Pursuant to its authority under section 5051 of Public Law 100-203, Nuclear Waste Policy Amendments Act of...

  16. How Are Questions That Students Ask in High Level Mathematics Classes Linked to General Giftedness?

    Science.gov (United States)

    Leikin, Roza; Koichu, Boris; Berman, Avi; Dinur, Sariga

    2017-01-01

    This paper presents a part of a larger study, in which we asked "How are learning and teaching of mathematics at high level linked to students' general giftedness?" We consider asking questions, especially student-generated questions, as indicators of quality of instructional interactions. In the part of the study presented in this…

  17. Effects of Crowding and Attention on High-Levels of Motion Processing and Motion Adaptation

    Science.gov (United States)

    Pavan, Andrea; Greenlee, Mark W.

    2015-01-01

    The motion after-effect (MAE) persists in crowding conditions, i.e., when the adaptation direction cannot be reliably perceived. The MAE originating from complex moving patterns spreads into non-adapted sectors of a multi-sector adapting display (i.e., phantom MAE). In the present study we used global rotating patterns to measure the strength of the conventional and phantom MAEs in crowded and non-crowded conditions, and when attention was directed to the adapting stimulus and when it was diverted away from the adapting stimulus. The results show that: (i) the phantom MAE is weaker than the conventional MAE, for both non-crowded and crowded conditions, and when attention was focused on the adapting stimulus and when it was diverted from it, (ii) conventional and phantom MAEs in the crowded condition are weaker than in the non-crowded condition. Analysis conducted to assess the effect of crowding on high-level of motion adaptation suggests that crowding is likely to affect the awareness of the adapting stimulus rather than degrading its sensory representation, (iii) for high-level of motion processing the attentional manipulation does not affect the strength of either conventional or phantom MAEs, neither in the non-crowded nor in the crowded conditions. These results suggest that high-level MAEs do not depend on attention and that at high-level of motion adaptation the effects of crowding are not modulated by attention. PMID:25615577

  18. High levels of soluble serum hemojuvelin in patients with congenital dyserythropoietic anemia type I

    NARCIS (Netherlands)

    Shalev, H.; Perez-Avraham, G.; Kapelushnik, J.; Levi, I.; Rabinovich, A.; Swinkels, D.W.; Brasse-Lagnel, C.; Tamary, H.

    2013-01-01

    OBJECTIVE: Congenital dyserythropoietic anemia (CDA) is a rare group of red blood cell disorders with ineffective erythropoiesis and secondary hemochromatosis. Inappropriate suppression of hepcidin and high levels of growth differentiation factor 15 (GDF15) have been described in CDA I and II

  19. Evaluation of the FIR Example using Xilinx Vivado High-Level Synthesis Compiler

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Zheming [Argonne National Lab. (ANL), Argonne, IL (United States); Finkel, Hal [Argonne National Lab. (ANL), Argonne, IL (United States); Yoshii, Kazutomo [Argonne National Lab. (ANL), Argonne, IL (United States); Cappello, Franck [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-07-28

    Compared to central processing units (CPUs) and graphics processing units (GPUs), field programmable gate arrays (FPGAs) have major advantages in reconfigurability and performance achieved per watt. This development flow has been augmented with high-level synthesis (HLS) flow that can convert programs written in a high-level programming language to Hardware Description Language (HDL). Using high-level programming languages such as C, C++, and OpenCL for FPGA-based development could allow software developers, who have little FPGA knowledge, to take advantage of the FPGA-based application acceleration. This improves developer productivity and makes the FPGA-based acceleration accessible to hardware and software developers. Xilinx Vivado HLS compiler is a high-level synthesis tool that enables C, C++ and System C specification to be directly targeted into Xilinx FPGAs without the need to create RTL manually. The white paper [1] published recently by Xilinx uses a finite impulse response (FIR) example to demonstrate the variable-precision features in the Vivado HLS compiler and the resource and power benefits of converting floating point to fixed point for a design. To get a better understanding of variable-precision features in terms of resource usage and performance, this report presents the experimental results of evaluating the FIR example using Vivado HLS 2017.1 and a Kintex Ultrascale FPGA. In addition, we evaluated the half-precision floating-point data type against the double-precision and single-precision data type and present the detailed results.

  20. High level model predictive control for plug-and-play process control with stability guaranty

    DEFF Research Database (Denmark)

    Michelsen, Axel Gottlieb; Stoustrup, Jakob

    2010-01-01

    In this paper a method for designing a stabilizing high level model predictive controller for a hierarchical plug- and-play process is presented. This is achieved by abstracting the lower layers of the controller structure as low order models with uncertainty and by using a robust model predictive...

  1. Effect of high levels of dietary molybdenum and sulphate on SA ...

    African Journals Online (AJOL)

    1988-10-29

    Oct 29, 1988 ... Effect of high levels of dietary molybdenum and sulphate on SA Mutton Merino sheep. I. Minerai status and ... reliable diagnostic index of copper deficiency in sheep in the presence of high concentrations of molybdenum and sulphate in ..... dates are poorly excreted by both the urinary and faecal routes in ...

  2. Pascal Semantics by a Combination of Denotational Semantics and High-level Petri Nets

    DEFF Research Database (Denmark)

    Jensen, Kurt; Schmidt, Erik Meineche

    1986-01-01

    This paper describes the formal semantics of a subset of PASCAL, by means of a semantic model based on a combination of denotational semantics and high-level Petri nets. It is our intention that the paper can be used as part of the written material for an introductory course in computer science....

  3. HTML::GMap-A High Level Perl Wrapper Around the Google Maps(TM) API

    Science.gov (United States)

    We have developed HTML::GMap, a generic, high-level Perl wrapper, to easily build web-based geographic map displays on top of the Google MapsTM Mapping Service. Using HTML::GMap, we built custom display tools to present the molecular diversity data generated by the National Science Foundation-suppor...

  4. Conceptual design report for immobilized high-level waste interim storage facility (Phase 1)

    Energy Technology Data Exchange (ETDEWEB)

    Burgard, K.C.

    1998-04-09

    The Hanford Site Canister Storage Building (CSB Bldg. 212H) will be utilized to interim store Phase 1 HLW products. Project W-464, Immobilized High-Level Waste Interim Storage, will procure an onsite transportation system and retrofit the CSB to accommodate the Phase 1 HLW products. The Conceptual Design Report establishes the Project W-464 technical and cost basis.

  5. Conceptual design report for immobilized high-level waste interim storage facility (Phase 1)

    Energy Technology Data Exchange (ETDEWEB)

    Burgard, K.C.

    1998-06-02

    The Hanford Site Canister Storage Building (CSB Bldg. 212H) will be utilized to interim store Phase 1 HLW products. Project W-464, Immobilized High-Level Waste Interim Storage, will procure an onsite transportation system and retrofit the CSB to accommodate the Phase 1 HLW products. The Conceptual Design Report establishes the Project W-464 technical and cost basis.

  6. High-level fusion of depth and intensity for pedestrian classification

    NARCIS (Netherlands)

    Rohrbach, M.; Enzweiler, M.; Gavrila, D.M.

    2009-01-01

    This paper presents a novel approach to pedestrian classification which involves a high-level fusion of depth and intensity cues. Instead of utilizing depth information only in a pre-processing step, we propose to extract discriminative spatial features (gradient orientation histograms and local

  7. Semantic-Aware Automatic Parallelization of Modern Applications Using High-Level Abstractions

    Energy Technology Data Exchange (ETDEWEB)

    Liao, C; Quinlan, D J; Willcock, J J; Panas, T

    2009-12-21

    Automatic introduction of OpenMP for sequential applications has attracted significant attention recently because of the proliferation of multicore processors and the simplicity of using OpenMP to express parallelism for shared-memory systems. However, most previous research has only focused on C and Fortran applications operating on primitive data types. Modern applications using high-level abstractions, such as C++ STL containers and complex user-defined class types, are largely ignored due to the lack of research compilers that are readily able to recognize high-level object-oriented abstractions and leverage their associated semantics. In this paper, we use a source-to-source compiler infrastructure, ROSE, to explore compiler techniques to recognize high-level abstractions and to exploit their semantics for automatic parallelization. Several representative parallelization candidate kernels are used to study semantic-aware parallelization strategies for high-level abstractions, combined with extended compiler analyses. Preliminary results have shown that semantics of abstractions can help extend the applicability of automatic parallelization to modern applications and expose more opportunities to take advantage of multicore processors.

  8. Using High Level Upperclass Undergraduates as TAs in Large Lower Division EFL Classes

    Science.gov (United States)

    Shi, Yeli

    2010-01-01

    The purpose of this paper is to offer a feasible way to show that the problem of large EFL courses for lower division can be solved by the use of high level upperclass undergraduates as teaching assistants in and out of class. The use of UTAs fragments the large class into seemingly small classes with view to stimulating interest and effective…

  9. B4G local area: high level requirements and system design

    DEFF Research Database (Denmark)

    Mogensen, Preben; Pajukoski, Kari; Raaf, Bernhard

    2012-01-01

    A next generation Beyond 4G (B4G) radio access technology is expected to become available around 2020 in order to cope with the exponential increase of mobile data traffic. In this paper, research motivations and high level requirements for a B4G local area concept are discussed. Our suggestions ...

  10. Elevated level of polysaccharides in a high level UV-B tolerant cell ...

    African Journals Online (AJOL)

    Jane

    2011-04-26

    Apr 26, 2011 ... Elevated level of polysaccharides in a high level UV-B tolerant cell line of Bupleurum scorzonerifolium Willd. Yuzhong Li1, Jing Fan1, Haiying Ma1, Fei Shen1, Ge Zhang1, Jianguang Wang1. , Guangmin Xia2,. Duoqing Fan3 and Suiyun Chen1*. 1School of Life Sciences, Yunnan University, Kunming ...

  11. A high-level power model for MPSoC on FPGA

    NARCIS (Netherlands)

    Piscitelli, R.; Pimentel, A.D.

    2011-01-01

    This paper presents a framework for high-level power estimation of multiprocessor systems-on-chip (MPSoC) architectures on FPGA. The technique is based on abstract execution profiles, called event signatures, and it operates at a higher level of abstraction than, e.g., commonly-used instruction-set

  12. A high-level power model for MPSoC on FPGA

    NARCIS (Netherlands)

    Piscitelli, R.; Pimentel, A.D.

    2012-01-01

    This paper presents a framework for high-level power estimation of multiprocessor systems-on-chip (MPSoC) architectures on FPGA. The technique is based on abstract execution profiles, called event signatures. As a result, it is capable of achieving good evaluation performance, thereby making the

  13. Chemical evolution of a high-level magma system: the Black Mountain volcanic center, southern Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, T.A.; Noble, D.C.; Younker, L.W.

    1983-09-01

    A comprehensive study of stratigraphically controlled samples of both lavas and ash-flow tuffs from the Black Mountain volcanic center enables us to evaluate magmatic processes. The results of this study are used to: (1) determine how this high-level magma system developed; (2) compare this system with other similar systems; and (3) correlate ash-flow sheets using their chemical characteristics.

  14. Comparison of Mental Toughness and Power Test Performances in High-Level Kickboxers by Competitive Success

    National Research Council Canada - National Science Library

    Slimani, Maamer; Miarka, Bianca; Briki, Walid; Cheour, Foued

    2016-01-01

    .... Thirty two high-level male kickboxers (winner = 16 and loser = 16: 21.2 ± 3.1 years, 1.73 ± 0.07 m, and 70.2 ± 9.4 kg) were analyzed using the CMJ, MBT tests and sports mental toughness questionnaire...

  15. Performance of sows fed high levels of nonstarch polysaccharides during gestation and lactation over three parities

    NARCIS (Netherlands)

    Peet-Schwering, van der C.M.C.; Kemp, B.; Binnendijk, G.P.; Hartog, den L.A.; Spoolder, H.A.M.; Verstegen, M.W.A.

    2003-01-01

    The effect of feeding sows a starch diet or a diet with a high level of nonstarch polysaccharides (NSP) during gestation, lactation, or both gestation and lactation during the first three parities on reproductive performance, body weight, and backfat was studied. Four-hundred and forty-four

  16. Bridging semantic gap between high-level and low-level features in ...

    Indian Academy of Sciences (India)

    Content-based video retrieval system aims at assisting a user to retrieve targeted video sequence in a large database. Most of the search engines use textual annotations to retrieve videos. These types of engines offer a low-level abstraction while the user seeks high-level semantics. Bridging this type of semantic gap in ...

  17. A Transformational Approach to VHDL and CDFG Based High-Level Synthesis: a Case Study

    NARCIS (Netherlands)

    Middelhoek, Peter F.A.; Middelhoek, P.F.A.; Mekenkamp, G.E.; Molenkamp, Egbert; Krol, Th.

    1995-01-01

    In this paper, a novel multi-target design methodology based on the concepts of transformational design, and its application to the interlaced-to-progressive scan conversion (IPSC) problem, are discussed. Starting from a single high-level behavioral specification in VHDL a direction detector used in

  18. Multi-threaded algorithms for GPGPU in the ATLAS High Level Trigger

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00212700; The ATLAS collaboration

    2016-01-01

    General purpose Graphics Processor Units (GPGPU) are being evaluated for possible future inclusion in an upgraded ATLAS High Level Trigger farm. We have developed a demonstrator including GPGPU implementations of Inner Detector and Muon tracking and Calorimeter clustering within the ATLAS software framework. ATLAS is a general purpose particle physics experiment located on the LHC collider at CERN. The ATLAS Trigger system consists of two levels, with Level-1 implemented in hardware and the High Level Trigger implemented in software running on a farm of commodity CPU. The High Level Trigger reduces the trigger rate from the 100 kHz Level-1 acceptance rate to 1.5 kHz for recording, requiring an average per-event processing time of ∼ 250 ms for this task. The selection in the high level trigger is based on reconstructing tracks in the Inner Detector and Muon Spectrometer and clusters of energy deposited in the Calorimeter. Performing this reconstruction within the available farm resources presents a significa...

  19. Structural integrity and potential failure modes of hanford high-level waste tanks

    Energy Technology Data Exchange (ETDEWEB)

    Han, F.C.

    1996-09-30

    Structural Integrity of the Hanford High-Level Waste Tanks were evaluated based on the existing Design and Analysis Documents. All tank structures were found adequate for the normal operating and seismic loads. Potential failure modes of the tanks were assessed by engineering interpretation and extrapolation of the existing engineering documents.

  20. The Role of High Level Play as a Predictor Social Functioning in Autism

    Science.gov (United States)

    Manning, Margaret M.; Wainwright, Laurel D.

    2010-01-01

    Play and social abilities of a group of children diagnosed with high functioning autism were compared to a second group diagnosed with a variety of developmental language disorders (DLD). The children with autism engaged in fewer acts of high level play. The children with autism also had significantly lower social functioning than the DLD group…

  1. Inhibition of Cardiomyogenesis in Embryocarcinoma Cells Induced by Long-Term High Level of Glucose

    Directory of Open Access Journals (Sweden)

    Wen-Juan Li

    2016-05-01

    Full Text Available Background/Aims: Cardiac myocytes constitute the first differentiated cell type during mammalian heart formation with the ability to beat spontaneously and rhythmically. Hyperglycemia is a primary risk factor for cardiovascular disease in pre-gestational diabetes mellitus (PGDM. However, the impact that hyperglycemia has on cardiac progenitors or on precursors differentiation remains poorly understood. The aim of the present study is to investigate whether hyperglycemia affects cardiomyogenesis of embryocarcinoma cells. Methods: P19CL6 cells differentiation induced by 1% DMSO was evaluated under either normal glucose (5.6 mmol/L or high level of glucose concentrations (20 mmol/L or 40 mmol/L. To investigate the effect of long-term high level of glucose on cardiomyocytes differentiation, sarcomeric α-actinin, peroxisome proliferator-activated receptor coactivator-1 (PGC-1α, transcription factor GATA4 and Nkx2.5 were assessed by qRT-PCR analysis, western blot and immunofluorescence. Results: We observed that long-term high level of glucose markedly reduced P19CL6 cells differentiation into cardiomyocytes. The change in PGC-1α expression was consistent with changes in cardiac muscle myosin expression after exposure to 20 mmol/L or 40 mmol/L of glucose. On the other hand, the high level of glucose concentration profoundly decreased both GATA4 and Nkx2-5 expressions from day 6 to day 12 after differentiation, which was induced by 1% DMSO. Conclusion: Our results elucidate that the effect resulting from the long-term exposure of cardiac progenitors to high level of glucose is associated with decreased expression of GATA4 and Nkx2.5, providing a novel mechanism by which high glucose is able to affect cell differentiation.

  2. A Study on Site Selecting for National Project including High Level Radioactive Waste Disposal

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kilyoo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    Many national projects are stopped since sites for the projects are not determined. The sites selections are hold by NIMBY for unpleasant facilities or by PYMFY for preferable facilities among local governments. The followings are the typical ones; NIMBY projects: high level radioactive waste disposal, THAAD, Nuclear power plant(NPP), etc. PIMFY projects: South-east new airport, KTX station, Research center for NPP decommission, etc. The site selection for high level radioactive waste disposal is more difficult problem, and thus government did not decide and postpone to a dead end street. Since it seems that there is no solution for site selection for high level radioactive waste disposal due to NIMBY among local governments, a solution method is proposed in this paper. To decide a high level radioactive waste disposal, the first step is to invite a bid by suggesting a package deal including PIMFY projects such as Research Center for NPP decommission. Maybe potential host local governments are asked to submit sealed bids indicating the minimum compensation sum that they would accept the high level radioactive waste disposal site. If there are more than one local government put in a bid, then decide an adequate site by considering both the accumulated PESS point and technical evaluation results. By considering how fairly preferable national projects and unpleasant national projects are distributed among local government, sites selection for NIMBY or PIMFY facilities is suggested. For NIMBY national projects, risk, cost benefit analysis is useful and required since it generates cost value to be used in the PESS. For many cases, the suggested method may be not adequate. However, similar one should be prepared, and be basis to decide sites for NIMBY or PIMFY national projects.

  3. Multilayer Protective Coatings for High-Level Nuclear Waste Storage Containers

    Science.gov (United States)

    Fusco, Michael

    Corrosion-based failures of high-level nuclear waste (HLW) storage containers are potentially hazardous due to a possible release of radionuclides through cracks in the canister due to corrosion, especially for above-ground storage (i.e. dry casks). Protective coatings have been proposed to combat these premature failures, which include stress-corrosion cracking and hydrogen-diffusion cracking, among others. The coatings are to be deposited in multiple thin layers as thin films on the outer surface of the stainless steel waste basket canister. Coating materials include: TiN, ZrO2, TiO2, Al 2O3, and MoS2, which together may provide increased resistances to corrosion and mechanical wear, as well as act as a barrier to hydrogen diffusion. The focus of this research is on the corrosion resistance and characterization of single layer coatings to determine the possible benefit from the use of the proposed coating materials. Experimental methods involve electrochemical polarization, both DC and AC techniques, and corrosion in circulating salt brines of varying pH. DC polarization allows for estimation of corrosion rates, passivation behavior, and a qualitative survey of localized corrosion, whereas AC electrochemistry has the benefit of revealing information about kinetics and interfacial reactions that is not obtainable using DC techniques. Circulation in salt brines for nearly 150 days revealed sustained adhesion of the coatings and minimal weight change of the steel samples. One-inch diameter steel coupons composed of stainless steel types 304 and 316 and A36 low alloy carbon steel were coated with single layers using magnetron sputtering with compound targets in an inert argon atmosphere. This resulted in very thin films for the metal-oxides based on low sputter rates. DC polarization showed that corrosion rates were very similar between bare and coated stainless steel samples, whereas a statistically significant decrease in uniform corrosion was measured on coated

  4. Temporal Processing Capacity in High-Level Visual Cortex Is Domain Specific.

    Science.gov (United States)

    Stigliani, Anthony; Weiner, Kevin S; Grill-Spector, Kalanit

    2015-09-09

    Prevailing hierarchical models propose that temporal processing capacity--the amount of information that a brain region processes in a unit time--decreases at higher stages in the ventral stream regardless of domain. However, it is unknown if temporal processing capacities are domain general or domain specific in human high-level visual cortex. Using a novel fMRI paradigm, we measured temporal capacities of functional regions in high-level visual cortex. Contrary to hierarchical models, our data reveal domain-specific processing capacities as follows: (1) regions processing information from different domains have differential temporal capacities within each stage of the visual hierarchy and (2) domain-specific regions display the same temporal capacity regardless of their position in the processing hierarchy. In general, character-selective regions have the lowest capacity, face- and place-selective regions have an intermediate capacity, and body-selective regions have the highest capacity. Notably, domain-specific temporal processing capacities are not apparent in V1 and have perceptual implications. Behavioral testing revealed that the encoding capacity of body images is higher than that of characters, faces, and places, and there is a correspondence between peak encoding rates and cortical capacities for characters and bodies. The present evidence supports a model in which the natural statistics of temporal information in the visual world may affect domain-specific temporal processing and encoding capacities. These findings suggest that the functional organization of high-level visual cortex may be constrained by temporal characteristics of stimuli in the natural world, and this temporal capacity is a characteristic of domain-specific networks in high-level visual cortex. Significance statement: Visual stimuli bombard us at different rates every day. For example, words and scenes are typically stationary and vary at slow rates. In contrast, bodies are dynamic

  5. Al2O3 influence on structural, elastic, thermal properties of Yb(3+) doped Ba-La-tellurite glass: evidence of reduction in self-radiation trapping at 1μm emission.

    Science.gov (United States)

    Balaji, S; Biswas, K; Sontakke, A D; Gupta, G; Ghosh, D; Annapurna, K

    2014-12-10

    Ba-La-tellurite glasses doped with Yb(3+) ions have been prepared through melt quenching technique by modifying their composition with the inclusion of varied concentration of Al2O3 to elucidate its effects on glass structural, elastic, thermal properties and Yb(3+) ion NIR luminescence performance. The FTIR spectral analysis indicates Al2O3 addition is promoting the conversion of BOs from NBOs which have been generated during the process of depolymerisation of main glass forming TeO4 units. The elastic properties of the glass revealed an improved rigidity of the glass network on addition of Al2O3. In concurrence to this, differential thermal analysis showed an increase in glass transition temperature with improved thermal stability factor. Also, Yb(3+) fluorescence dynamics demonstrated that, Al2O3 inclusion helps in restraining the detrimental radiation trapping of ∼1μm emission. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Development of anodic stripping voltametry for the determination of palladium in high level nuclear waste

    Energy Technology Data Exchange (ETDEWEB)

    Bhardwaj, T. K. [North Carolina State University, Raleigh (United States); Sharma, H. S.; Affarwal, S. K. [Bhabha Atomic Research Centre, Mumbai (India); Jain, P. C. [Meerut College, Meerut (India)

    2012-12-15

    Deposition potential, deposition time, square wave frequency, rotation speed of the rotating disc electrode, and palladium concentration were studied on a Glassy Carbon Electrode (GCE) in 0.01M HCl for the determination of palladium in High Level Nuclear Waste (HLNW) by anodic stripping voltammetry. Experimental conditions were optimized for the determination of palladium at two different, 10-8 and 10-7 M, levels. Error and standard deviation of this method were under 1% for all palladium standard solutions. The developed technique was successfully applied as a subsidiary method for the determination of palladium in simulated high level nuclear waste with very good precision and high accuracy (under 1 % error and standard deviation).

  7. Southern routes for high-level radioactive waste: Agencies, contacts, and designations

    Energy Technology Data Exchange (ETDEWEB)

    1991-05-01

    The Southern Routes for High-Level Radioactive Waste: Agencies, Contacts and Designations is a compendium of sixteen southern states' routing programs for the transportation of high-level radioactive materials. The report identifies the state-designated routing agencies as defined under 49 Code of Federal Regulations (CFR) Part 171 and provides a reference to the source and scope of the agencies' rulemaking authority. Additionally, the state agency and contact designated by the state's governor to receive advance notification and shipment routing information under 10 CFR Parts 71 and 73 are also listed. This report also examines alternative route designations made by southern states and the lessons that were learned from the designation process.

  8. Southern routes for high-level radioactive waste: Agencies, contacts, and designations

    Energy Technology Data Exchange (ETDEWEB)

    1991-05-01

    The Southern Routes for High-Level Radioactive Waste: Agencies, Contacts and Designations is a compendium of sixteen southern states` routing programs for the transportation of high-level radioactive materials. The report identifies the state-designated routing agencies as defined under 49 Code of Federal Regulations (CFR) Part 171 and provides a reference to the source and scope of the agencies` rulemaking authority. Additionally, the state agency and contact designated by the state`s governor to receive advance notification and shipment routing information under 10 CFR Parts 71 and 73 are also listed. This report also examines alternative route designations made by southern states and the lessons that were learned from the designation process.

  9. The ATLAS online High Level Trigger framework experience reusing offline software components in the ATLAS trigger

    CERN Document Server

    Wiedenmann, W

    2009-01-01

    Event selection in the Atlas High Level Trigger is accomplished to a large extent by reusing software components and event selection algorithms developed and tested in an offline environment. Many of these offline software modules are not specifically designed to run in a heavily multi-threaded online data flow environment. The Atlas High Level Trigger (HLT) framework based on the Gaudi and Atlas Athena frameworks, forms the interface layer, which allows the execution of the HLT selection and monitoring code within the online run control and data flow software. While such an approach provides a unified environment for trigger event selection across all of Atlas, it also poses strict requirements on the reused software components in terms of performance, memory usage and stability. Experience of running the HLT selection software in the different environments and especially on large multi-node trigger farms has been gained in several commissioning periods using preloaded Monte Carlo events, in data taking peri...

  10. West Valley demonstration project: alternative processes for solidifying the high-level wastes

    Energy Technology Data Exchange (ETDEWEB)

    Holton, L.K.; Larson, D.E.; Partain, W.L.; Treat, R.L.

    1981-10-01

    In 1980, the US Department of Energy (DOE) established the West Valley Solidification Project as the result of legislation passed by the US Congress. The purpose of this project was to carry out a high level nuclear waste management demonstration project at the Western New York Nuclear Service Center in West Valley, New York. The DOE authorized the Pacific Northwest Laboratory (PNL), which is operated by Battelle Memorial Institute, to assess alternative processes for treatment and solidification of the WNYNSC high-level wastes. The Process Alternatives Study is the suject of this report. Two pretreatment approaches and several waste form processes were selected for evaluation in this study. The two waste treatment approaches were the salt/sludge separation process and the combined waste process. Both terminal and interim waste form processes were studied.

  11. Automatic Generation of Web Applications from Visual High-Level Functional Web Components

    Directory of Open Access Journals (Sweden)

    Quan Liang Chen

    2009-01-01

    Full Text Available This paper presents high-level functional Web components such as frames, framesets, and pivot tables, which conventional development environments for Web applications have not yet supported. Frameset Web components provide several editing facilities such as adding, deleting, changing, and nesting of framesets to make it easier to develop Web applications that use frame facilities. Pivot table Web components sum up various kinds of data in two dimensions. They reduce the amount of code to be written by developers greatly. The paper also describes the system that implements these high-level functional components as visual Web components. This system assists designers in the development of Web applications based on the page-transition framework that models a Web application as a set of Web page transitions, and by using visual Web components, makes it easier to write processes to be executed when a Web page transfers to another.

  12. Using the High-Level Based Program Interface to Facilitate the Large Scale Scientific Computing

    Directory of Open Access Journals (Sweden)

    Yizi Shang

    2014-01-01

    Full Text Available This paper is to make further research on facilitating the large-scale scientific computing on the grid and the desktop grid platform. The related issues include the programming method, the overhead of the high-level program interface based middleware, and the data anticipate migration. The block based Gauss Jordan algorithm as a real example of large-scale scientific computing is used to evaluate those issues presented above. The results show that the high-level based program interface makes the complex scientific applications on large-scale scientific platform easier, though a little overhead is unavoidable. Also, the data anticipation migration mechanism can improve the efficiency of the platform which needs to process big data based scientific applications.

  13. Efficient, reliable and fast high-level triggering using a bonsai boosted decision tree

    Science.gov (United States)

    Gligorov, V. V.; Williams, M.

    2013-02-01

    High-level triggering is a vital component of many modern particle physics experiments. This paper describes a modification to the standard boosted decision tree (BDT) classifier, the so-called bonsai BDT, that has the following important properties: it is more efficient than traditional cut-based approaches; it is robust against detector instabilities, and it is very fast. Thus, it is fit-for-purpose for the online running conditions faced by any large-scale data acquisition system.

  14. Efficient, reliable and fast high-level triggering using a bonsai boosted decision tree

    CERN Document Server

    Gligorov, V.V.

    2013-01-01

    High-level triggering is a vital component in many modern particle physics experiments. This paper describes a modification to the standard boosted decision tree (BDT) classifier, the so-called "bonsai" BDT, that has the following important properties: it is more efficient than traditional cut-based approaches; it is robust against detector instabilities, and it is very fast. Thus, it is fit-for-purpose for the online running conditions faced by any large-scale data acquisition system.

  15. EEG oscillations entrain their phase to high-level features of speech sound.

    Science.gov (United States)

    Zoefel, Benedikt; VanRullen, Rufin

    2016-01-01

    Phase entrainment of neural oscillations, the brain's adjustment to rhythmic stimulation, is a central component in recent theories of speech comprehension: the alignment between brain oscillations and speech sound improves speech intelligibility. However, phase entrainment to everyday speech sound could also be explained by oscillations passively following the low-level periodicities (e.g., in sound amplitude and spectral content) of auditory stimulation-and not by an adjustment to the speech rhythm per se. Recently, using novel speech/noise mixture stimuli, we have shown that behavioral performance can entrain to speech sound even when high-level features (including phonetic information) are not accompanied by fluctuations in sound amplitude and spectral content. In the present study, we report that neural phase entrainment might underlie our behavioral findings. We observed phase-locking between electroencephalogram (EEG) and speech sound in response not only to original (unprocessed) speech but also to our constructed "high-level" speech/noise mixture stimuli. Phase entrainment to original speech and speech/noise sound did not differ in the degree of entrainment, but rather in the actual phase difference between EEG signal and sound. Phase entrainment was not abolished when speech/noise stimuli were presented in reverse (which disrupts semantic processing), indicating that acoustic (rather than linguistic) high-level features play a major role in the observed neural entrainment. Our results provide further evidence for phase entrainment as a potential mechanism underlying speech processing and segmentation, and for the involvement of high-level processes in the adjustment to the rhythm of speech. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. High Level Environmental Screening Study for Offshore Wind Farm Developments – Marine Habitats and Species Project

    OpenAIRE

    Hiscock, K; Tyler-Walters, H.; Jones, H.

    2002-01-01

    High level environmental screening study for offshore wind farm developments – marine habitats and species \\ud This report provides an awareness of the environmental issues related to marine habitats and species for developers and regulators of offshore wind farms. \\ud The information is also relevant to other offshore renewable energy developments. \\ud The marine habitats and species considered are those associated with the seabed, seabirds, and sea mammals. The report concludes that the fol...

  17. Development of site suitability criteria for the high level waste repository for Lawrence Livermore Laboratories

    Energy Technology Data Exchange (ETDEWEB)

    1977-06-01

    Results of our mining, geological and geotechnical studies provided in support of the development of site suitability criteria for the high level waste repository are presented. The primary purpose of the work was the identification and development of appropriate geotechnical descriptors and coefficients required for the Site Suitability Repository Model. This model was developed by The Analytic Sciences Corporation (TASC) of Reading, Massachusetts and is not described in this report.

  18. Outcomes of hook of hamate fracture excision in high-level amateur athletes.

    Science.gov (United States)

    Devers, Brandon N; Douglas, Keith C; Naik, Rishi D; Lee, Donald H; Watson, Jeffry T; Weikert, Douglas R

    2013-01-01

    To determine the overall long-term postoperative clinical and functional results of high-level amateur athletes after hook of hamate excision, based on complications; return to sport; Disabilities of the Arm, Shoulder, and Hand (DASH) score; and a self-reported questionnaire. We evaluated 11 patients representing 12 cases of hook of hamate excision. All patients were high-level amateur athletes (rising collegiate or collegiate level). We performed a retrospective chart review to elicit information pertaining to the patient's injury. We assessed long-term postoperative outcomes with a self-reported questionnaire, the DASH form, and the DASH Sport/Performing Arts Module form. All patients successfully returned to full participation in their respective sports an average of 6 weeks after surgery. The average postoperative DASH score was less than 1, and all patients scored a 0 on the DASH Sports form. There was a significant improvement in preoperative pain after surgical intervention. There was no significant difference between preinjury and postoperative performance scores. Finally, every patient was very satisfied with the surgical outcome. There was only 1 postoperative complication in which a patient developed transient ulnar nerve paresthesias, which completely resolved by 6 weeks after surgery. Surgical excision of hook of hamate fractures in high-level amateur athletes allows for successful return to sports participation at preinjury performance levels, achievement of normal function as measured by validated objective outcome measures, significant reduction in pain, and high overall patient satisfaction. We consider surgical excision to be a safe and effective technique to restore normal function and hasten return to play for high-level amateur athletes. Therapeutic IV. Copyright © 2013 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  19. Removal of Aerosol Particles Generated from Vitrification Process for High-Level Liquid Wastes

    OpenAIRE

    加藤 功

    1990-01-01

    The vitrification technology has been developed for the high-level liquid waste (HLLW) from reprocessing nuclear spent fuel in PNC. The removal performance of the aerosol particles generated from the melting process was studied in a nonradioactive full-scale mock-up test facility (MTF). The off-gas treatment system consists of submerged bed scrubber (SBS), venturi scrubber, NOx absorber, high efficiency mist eliminater (HEME). Deoomtamination factors (DFs) were derived from the mass ratio of ...

  20. Multi-Threaded Algorithms for GPGPU in the ATLAS High Level Trigger

    Science.gov (United States)

    Conde Muíño, P.; ATLAS Collaboration

    2017-10-01

    General purpose Graphics Processor Units (GPGPU) are being evaluated for possible future inclusion in an upgraded ATLAS High Level Trigger farm. We have developed a demonstrator including GPGPU implementations of Inner Detector and Muon tracking and Calorimeter clustering within the ATLAS software framework. ATLAS is a general purpose particle physics experiment located on the LHC collider at CERN. The ATLAS Trigger system consists of two levels, with Level-1 implemented in hardware and the High Level Trigger implemented in software running on a farm of commodity CPU. The High Level Trigger reduces the trigger rate from the 100 kHz Level-1 acceptance rate to 1.5 kHz for recording, requiring an average per-event processing time of ∼ 250 ms for this task. The selection in the high level trigger is based on reconstructing tracks in the Inner Detector and Muon Spectrometer and clusters of energy deposited in the Calorimeter. Performing this reconstruction within the available farm resources presents a significant challenge that will increase significantly with future LHC upgrades. During the LHC data taking period starting in 2021, luminosity will reach up to three times the original design value. Luminosity will increase further to 7.5 times the design value in 2026 following LHC and ATLAS upgrades. Corresponding improvements in the speed of the reconstruction code will be needed to provide the required trigger selection power within affordable computing resources. Key factors determining the potential benefit of including GPGPU as part of the HLT processor farm are: the relative speed of the CPU and GPGPU algorithm implementations; the relative execution times of the GPGPU algorithms and serial code remaining on the CPU; the number of GPGPU required, and the relative financial cost of the selected GPGPU. We give a brief overview of the algorithms implemented and present new measurements that compare the performance of various configurations exploiting GPGPU cards.

  1. Geological aspects of the high level waste and spent fuel disposal programme in Slovakia

    Energy Technology Data Exchange (ETDEWEB)

    Matej, Gedeon; Milos, Kovacik; Jozef, Hok [Geological Survey of Slovak Republic, Bratislava (Slovakia)

    2001-07-01

    An autonomous programme for development of a deep geological high level waste and spent fuel disposal began in 1996. One of the most important parts in the programme is siting of the future deep seated disposal. Geological conditions in Slovakia are complex due to the Alpine type tectonics that formed the geological environment during Tertiary. Prospective areas include both crystalline complexes (tonalites, granites, granodiorites) and Neogene (Miocene) argillaceous complexes. (author)

  2. Review of High Level Endodontic Research in PubMed Index Journals from Iran

    OpenAIRE

    Eghbal, Mohammad Jafar; Torabzadeh, Hassan

    2012-01-01

    Introduction This study aimed to evaluate patents as well as high level researches including systematic reviews/meta-analyses and randomized controlled clinical trials (RCT) published in scientific journals by Iranians endodontic. Materials and Methods The study started with targeted searches of PubMed as well as World Intellectual Property Organization and United State Patent and Trademark Office. Results There were 4 filed/granted patents, 2 systematic reviews/meta-analyses and 25 RCTs. Pat...

  3. High-Level Production of Heterologous Protein by Engineered Yeasts Grown in Cottage Cheese Whey

    Science.gov (United States)

    Maullu, Carlo; Lampis, Giorgio; Desogus, Alessandra; Ingianni, Angela; Rossolini, Gian Maria; Pompei, Raffaello

    1999-01-01

    Cottage cheese whey is a cheese industry by-product still rich in proteins and lactose. Its recycling is seldom cost-effective. In this work we show that the lactose-utilizing yeast Kluyveromyces lactis, engineered for production of recombinant human lysozyme, can be grown in cottage cheese whey, resulting in high-level production of the heterologous protein (125 μg/ml). PMID:10347071

  4. High-Level Production of Heterologous Protein by Engineered Yeasts Grown in Cottage Cheese Whey

    OpenAIRE

    Maullu, Carlo; Lampis, Giorgio; Desogus, Alessandra; Ingianni, Angela; Rossolini, Gian Maria; Pompei, Raffaello

    1999-01-01

    Cottage cheese whey is a cheese industry by-product still rich in proteins and lactose. Its recycling is seldom cost-effective. In this work we show that the lactose-utilizing yeast Kluyveromyces lactis, engineered for production of recombinant human lysozyme, can be grown in cottage cheese whey, resulting in high-level production of the heterologous protein (125 μg/ml).

  5. Composite quarterly technical report long-term high-level-waste technology, October-December 1981

    Energy Technology Data Exchange (ETDEWEB)

    Cornman, W.R. (comp.)

    1982-06-01

    This document summarizes work performed at participating sites on the immobilization of high-level wastes from the chemical reprocessing of reactor fuels. The plan is to develop waste form alternatives for each of the three DOE sites (SRP, ICPP, and Hanford). Progress is reported in the following areas: waste preparation; fixation in glass, concrete, tailored ceramics, and coated particles; process and equipment development; and final handling. 12 figures, 19 tables. (DLC)

  6. ProFET: Feature engineering captures high-level protein functions.

    Science.gov (United States)

    Ofer, Dan; Linial, Michal

    2015-11-01

    The amount of sequenced genomes and proteins is growing at an unprecedented pace. Unfortunately, manual curation and functional knowledge lag behind. Homologous inference often fails at labeling proteins with diverse functions and broad classes. Thus, identifying high-level protein functionality remains challenging. We hypothesize that a universal feature engineering approach can yield classification of high-level functions and unified properties when combined with machine learning approaches, without requiring external databases or alignment. In this study, we present a novel bioinformatics toolkit called ProFET (Protein Feature Engineering Toolkit). ProFET extracts hundreds of features covering the elementary biophysical and sequence derived attributes. Most features capture statistically informative patterns. In addition, different representations of sequences and the amino acids alphabet provide a compact, compressed set of features. The results from ProFET were incorporated in data analysis pipelines, implemented in python and adapted for multi-genome scale analysis. ProFET was applied on 17 established and novel protein benchmark datasets involving classification for a variety of binary and multi-class tasks. The results show state of the art performance. The extracted features' show excellent biological interpretability. The success of ProFET applies to a wide range of high-level functions such as subcellular localization, structural classes and proteins with unique functional properties (e.g. neuropeptide precursors, thermophilic and nucleic acid binding). ProFET allows easy, universal discovery of new target proteins, as well as understanding the features underlying different high-level protein functions. ProFET source code and the datasets used are freely available at https://github.com/ddofer/ProFET. michall@cc.huji.ac.il Supplementary data are available at Bioinformatics online. © The Author 2015. Published by Oxford University Press. All rights

  7. Developmental and Cognitive Characteristics of ?High-Level Potentialities? (Highly Gifted) Children

    OpenAIRE

    Laurence Vaivre-Douret

    2011-01-01

    This study covers the interesting field of the development in gifted children which is often neglected in pediatrics because psychomotor development data are still rare, since “gifted” children are generally noticed towards the end of their primary schooling by IQ measurement. Developmental studies have shown the evidence from several fields that children identified as “high-level potentialities” or “intellectually gifted” develop sensory, locomotor, neuropsychological, and language skills ea...

  8. Mercury Phase II Study - Mercury Behavior across the High-Level Waste Evaporator System

    Energy Technology Data Exchange (ETDEWEB)

    Bannochie, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Crawford, C. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Jackson, D. G. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Shah, H. B. [Savannah River Remediation, LLC., Aiken, SC (United States); Jain, V. [Savannah River Remediation, LLC., Aiken, SC (United States); Occhipinti, J. E. [Savannah River Remediation, LLC., Aiken, SC (United States); Wilmarth, W. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-06-17

    The Mercury Program team’s effort continues to develop more fundamental information concerning mercury behavior across the liquid waste facilities and unit operations. Previously, the team examined the mercury chemistry across salt processing, including the Actinide Removal Process/Modular Caustic Side Solvent Extraction Unit (ARP/MCU), and the Defense Waste Processing Facility (DWPF) flowsheets. This report documents the data and understanding of mercury across the high level waste 2H and 3H evaporator systems.

  9. Criticality Safety Evaluation of Hanford Site High Level Waste Storage Tanks

    Energy Technology Data Exchange (ETDEWEB)

    ROGERS, C.A.

    2000-02-17

    This criticality safety evaluation covers operations for waste in underground storage tanks at the high-level waste tank farms on the Hanford site. This evaluation provides the bases for criticality safety limits and controls to govern receipt, transfer, and long-term storage of tank waste. Justification is provided that a nuclear criticality accident cannot occur for tank farms operations, based on current fissile material and operating conditions.

  10. Region-of-Interest Selection for ATLAS High Level Trigger and Offline Software Environments

    CERN Document Server

    Mello, AG; Brandt, S

    2003-01-01

    Among the many challenges presented by the future ATLAS detector and LHC accelerator are the high data taking rate and volume and the derivation of a rapid trigger decision within limited computing and networking resources. To address this challenge, within the High Level Trigger (HLT) system, a novel Region-of-Interest (RoI) mechanism is used which dramatically reduces the relevant fiducial volume necessary to be readout and processed to small regions guided by the hardware-based first level trigger.

  11. A Study of the Leadership and Coaching Behaviours of High Level Hurling Coaches

    OpenAIRE

    McCormack, Paddy

    2007-01-01

    The purpose of the study was to examine the various factors which have an impact on the leadership and coaching behaviours of high-level hurling coaches. A considerable gap exists between the importance assigned to athletic leadership and the efforts to understand it (Reimer & Chelladurai, 1995). Inter-county senior hurling coaches (n = 35) were surveyed on a demographic questionnaire and their self-perception of leadership and coaching behaviours were analysed using the Revised Leadership Sc...

  12. Knowledge of the self-control benefits of high-level versus low-level construal.

    Science.gov (United States)

    MacGregor, Karen E; Carnevale, Jessica J; Dusthimer, Nicole E; Fujita, Kentaro

    2017-04-01

    Research indicates that inducing high-level construal (processing that highlights invariant, essential features) relative to low-level construal (processing that highlights idiosyncratic, peripheral features) promotes self-control (Fujita & Carnevale, 2012). In the present work, we investigate to what extent people recognize the self-control benefits of high-level construal, and explore the consequences of this knowledge. Studies 1 and 2 provide initial evidence that individuals are aware that high-level relative to low-level construal promotes self-control in the dieting domain. Studies 3 and 4 find that individual differences in this knowledge predict self-control success outcomes (i.e., body mass index) among those who are motivated by dieting goals. Examining academics as a domain of self-control, Study 5 demonstrates that those with higher knowledge of construal level's impact on self-control earned higher end-of-semester grades to the extent that they were motivated to do well academically. Theoretical and practical implications of these findings are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  13. Hormonal and neuromuscular responses to high-level middle- and long-distance competition.

    Science.gov (United States)

    Balsalobre-Fernández, Carlos; Tejero-González, Carlos M; del Campo-Vecino, Juan

    2014-09-01

    The purpose of this study was to analyze the effects of high-level competition on salivary free cortisol, countermovement jump (CMJ), and rating of perceived exertion (RPE) and the relationships between these fatigue indicators in a group of elite middle- and long-distance runners. The salivary free cortisol levels and CMJ height of 10 high-level middle- and long-distance runners (7 men, 3 women; age 27.6 ± 5.1y) competing in 800-m, 1500-m, 3000-m, or 5000-m events in the 2013 Spanish National Championships were measured throughout a 4-wk baseline period, then again before and after their respective races on the day of the competition. Athletes' RPE was also measured after their races. Cortisol increased significantly after the race compared with the value measured 90 min before the race (+98.3%, g = 0.82, P long-distance runners. These results show the suitability of the CMJ for monitoring multifactorial competition responses in high-level middle- and long-distance runners.

  14. Towards Implementation of a Generalized Architecture for High-Level Quantum Programming Language

    Science.gov (United States)

    Ameen, El-Mahdy M.; Ali, Hesham A.; Salem, Mofreh M.; Badawy, Mahmoud

    2017-08-01

    This paper investigates a novel architecture to the problem of quantum computer programming. A generalized architecture for a high-level quantum programming language has been proposed. Therefore, the programming evolution from the complicated quantum-based programming to the high-level quantum independent programming will be achieved. The proposed architecture receives the high-level source code and, automatically transforms it into the equivalent quantum representation. This architecture involves two layers which are the programmer layer and the compilation layer. These layers have been implemented in the state of the art of three main stages; pre-classification, classification, and post-classification stages respectively. The basic building block of each stage has been divided into subsequent phases. Each phase has been implemented to perform the required transformations from one representation to another. A verification process was exposed using a case study to investigate the ability of the compiler to perform all transformation processes. Experimental results showed that the efficacy of the proposed compiler achieves a correspondence correlation coefficient about R ≈ 1 between outputs and the targets. Also, an obvious achievement has been utilized with respect to the consumed time in the optimization process compared to other techniques. In the online optimization process, the consumed time has increased exponentially against the amount of accuracy needed. However, in the proposed offline optimization process has increased gradually.

  15. Prevalence of a characteristic gene profile in high-level rhythmic gymnasts.

    Science.gov (United States)

    Tringali, Cristina; Brivio, Ilaria; Stucchi, Beatrice; Silvestri, Ilaria; Scurati, Raffaele; Michielon, Giovanni; Alberti, Giampietro; Venerando, Bruno

    2014-01-01

    High-level physical performance in rhythmic gymnastics is influenced by numerous skills and anthropometric factors. In order to understand if genetic predisposition could play a role to define the elite rhythmic gymnast phenotype, we analysed the frequency of common polymorphisms linked to genes correlated with body mass (ADRB2 and FTO), explosive strength (ACTN3 and ACE), and joint mobility (COL5A1), in 42 gymnasts involved in National and International events, and in 42 control girls. Our results demonstrated that high-level rhythmic gymnasts constituted a genetically selected population showing higher frequency of: (a) ADRB2 and FTO alleles linked to low body mass index and low fat mass; (b) COL5A1 CT genotype linked to high joint mobility and to the occurrence of genu recurvatum, but also to a higher incidence of injuries. ACTN3 and ACE polymorphisms did not appear to be connected with the phenotype of high-level rhythmic gymnast. Based on these data, it can be assumed that these polymorphisms could positively affect the phenotype and performance of gymnasts.

  16. Specifying the Concept of Future Generations for Addressing Issues Related to High-Level Radioactive Waste.

    Science.gov (United States)

    Kermisch, Celine

    2016-12-01

    The nuclear community frequently refers to the concept of "future generations" when discussing the management of high-level radioactive waste. However, this notion is generally not defined. In this context, we have to assume a wide definition of the concept of future generations, conceived as people who will live after the contemporary people are dead. This definition embraces thus each generation following ours, without any restriction in time. The aim of this paper is to show that, in the debate about nuclear waste, this broad notion should be further specified and to clarify the related implications for nuclear waste management policies. Therefore, we provide an ethical analysis of different management strategies for high-level waste in the light of two principles, protection of future generations-based on safety and security-and respect for their choice. This analysis shows that high-level waste management options have different ethical impacts across future generations, depending on whether the memory of the waste and its location is lost, or not. We suggest taking this distinction into account by introducing the notions of "close future generations" and "remote future generations", which has important implications on nuclear waste management policies insofar as it stresses that a retrievable disposal has fewer benefits than usually assumed.

  17. Impact of high-level sport practice on anal incontinence in a healthy young female population.

    Science.gov (United States)

    Vitton, Véronique; Baumstarck-Barrau, Karine; Brardjanian, Sarah; Caballe, Isabelle; Bouvier, Michel; Grimaud, Jean-Charles

    2011-05-01

    Regular physical activity usually confers health benefits, but high-level sport may induce harmful outcomes, such as pelvic floor dysfunction. Urinary incontinence (UI) was previously documented, but few data are available about anal incontinence (AI) in female athletes. Our aim was to determine the role of high-level sport practice on AI in a young, healthy female population. In this cross-sectional study, we included women aged 18-40 years. Self-administered questionnaires were delivered to each female volunteer. Two groups were defined: (1) intensive sport (IS) group: high-level sport (>8 hours weekly), and (2) nonintensive sport (NIS) group: all other subjects. Of the 393 women enrolled, 169 were in the IS group and 224 were in the NIS group. Women of the IS group were significantly younger than the others (21.74±4.28 vs. 24.87±5.61 years, psport appears to be a significant independent risk factor for AI in healthy young women. These results suggest that preventive measures, such as pelvic floor muscle training, may be proposed for this young population.

  18. High level cross of the esophagus with the descending aorta in scoliosis: CT study

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Koji; Kikuno, Motoyuki; Hyodoh, Hideki [Jichi Medical School Hospital, Minamikawachi-machi, Tochigi-ken (Japan)] [and others

    1996-05-01

    The esophagus occasionally crosses the descending aorta at an unusually high level (3-5 cm inferior to the carina) in right-sided scoliosis. The purpose of this study was to analyze the mechanism of this finding. We prospectively evaluated thoracic CT scans in 30 patients with right-sided scoliosis. We assessed the alterations in the positions of the esophagus and the descending aorta by the thoracic deformity. The descending aorta followed the scoliotic curve of the spine in 26 (87%) patients. The esophagus followed the scoliotic curve of the spine in 14 (47%) patients and did not in 16 (53%). The anteroposterior diameter of the thorax in the former group was significantly smaller than that in the latter (p < 0.01). High level cross of both structures was identified in 14 (47%) patients, and all of them belonged to the group in which the esophagus did not follow the scoliotic curve of the spine. The unusual high level cross of the esophagus with the descending aorta occasionally seen in scoliosis is due to a difference in the positional alterations of the two structures resulting from the scoliosis. 6 refs., 3 figs.

  19. Ontology-Based High-Level Context Inference for Human Behavior Identification

    Directory of Open Access Journals (Sweden)

    Claudia Villalonga

    2016-09-01

    Full Text Available Recent years have witnessed a huge progress in the automatic identification of individual primitives of human behavior, such as activities or locations. However, the complex nature of human behavior demands more abstract contextual information for its analysis. This work presents an ontology-based method that combines low-level primitives of behavior, namely activity, locations and emotions, unprecedented to date, to intelligently derive more meaningful high-level context information. The paper contributes with a new open ontology describing both low-level and high-level context information, as well as their relationships. Furthermore, a framework building on the developed ontology and reasoning models is presented and evaluated. The proposed method proves to be robust while identifying high-level contexts even in the event of erroneously-detected low-level contexts. Despite reasonable inference times being obtained for a relevant set of users and instances, additional work is required to scale to long-term scenarios with a large number of users.

  20. Algorithms, performance, and development of the ATLAS High-level Trigger

    CERN Document Server

    Nagano, K; The ATLAS collaboration

    2013-01-01

    The ATLAS trigger system has been used for the online event selection for three years of LHC data-taking and is preparing for the next run. The trig- ger system consists of a hardware level-1 (L1) and a software high-level trigger (HLT). The high-level trigger is currently implemented in a region-of-interest based level-2 (L2) stage and a event filter (EF) operating after even building with offline-like software. During the past three years, the luminosity and pile- up (number of collisions per beam crossing) has increased significantly placing escalating demands on the rejection and timing performace. The HLT algo- rithms advanced during this period to maintain and even improve performance. For the next run, the boundary between the L2 and EF will be removed, so that there is only one high-level trigger which can operate either on regions of interest or on the full event depending on the objects found in the event either by the L1 or by the HLT itself. This talk will discuss the algorithms, performance and o...

  1. Demonstrating Reliable High Level Waste Slurry Sampling Techniques to Support Hanford Waste Processing

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Steven E.

    2013-11-11

    The Hanford Tank Operations Contractor (TOC) and the Hanford Waste Treatment and Immobilization Plant (WTP) contractor are both engaged in demonstrating mixing, sampling, and transfer system capability using simulated Hanford High-Level Waste (HL W) formulations. This work represents one of the remaining technical issues with the high-level waste treatment mission at Hanford. The TOC must demonstrate the ability to adequately mix and sample high-level waste feed to meet the WTP Waste Acceptance Criteria and Data Quality Objectives. The sampling method employed must support both TOC and WTP requirements. To facilitate information transfer between the two facilities the mixing and sampling demonstrations are led by the One System Integrated Project Team. The One System team, Waste Feed Delivery Mixing and Sampling Program, has developed a full scale sampling loop to demonstrate sampler capability. This paper discusses the full scale sampling loops ability to meet precision and accuracy requirements, including lessons learned during testing. Results of the testing showed that the Isolok(R) sampler chosen for implementation provides precise, repeatable results. The Isolok(R) sampler accuracy as tested did not meet test success criteria. Review of test data and the test platform following testing by a sampling expert identified several issues regarding the sampler used to provide reference material used to judge the Isolok's accuracy. Recommendations were made to obtain new data to evaluate the sampler's accuracy utilizing a reference sampler that follows good sampling protocol.

  2. Ethical challenges related to elder care. High level decision-makers' experiences

    Directory of Open Access Journals (Sweden)

    Kihlgren Mona

    2007-04-01

    Full Text Available Abstract Background Few empirical studies have been found that explore ethical challenges among persons in high public positions that are responsible for elder care. The aim of this paper was to illuminate the meaning of being in ethically difficult situations related to elder care as experienced by high level decision-makers. Methods A phenomenological-hermeneutic method was used to analyse the eighteen interviews conducted with political and civil servant high level decision-makers at the municipality and county council level from two counties in Sweden. The participants worked at a planning and control as well as executive level and had both budget and quality of elder care responsibilities. Results Both ethical dilemmas and the meaning of being in ethically difficult situations related to elder care were revealed. No differences were seen between the politicians and the civil servants. The ethical dilemmas mostly concerned dealings with extensive care needs and working with a limited budget. The dilemmas were associated with a lack of good care and a lack of agreement concerning care such as vulnerable patients in inappropriate care settings, weaknesses in medical support, dissimilar focuses between the caring systems, justness in the distribution of care and deficient information. Being in ethically difficult situations was challenging. Associated with them were experiences of being exposed, having to be strategic and living with feelings such as aloneness and loneliness, uncertainty, lack of confirmation, the risk of being threatened or becoming a scapegoat and difficult decision avoidance. Conclusion Our paper provides further insight into the ethical dilemmas and ethical challenges met by high level decision-makers', which is important since the overall responsibility for elder care that is also ethically defensible rests with them. They have power and their decisions affect many stakeholders in elder care. Our results can be used to

  3. DESIGN ANALYSIS FOR THE DEFENSE HIGH-LEVEL WASTE DISPOSAL CONTAINER

    Energy Technology Data Exchange (ETDEWEB)

    G. Radulesscu; J.S. Tang

    2000-06-07

    The purpose of ''Design Analysis for the Defense High-Level Waste Disposal Container'' analysis is to technically define the defense high-level waste (DHLW) disposal container/waste package using the Waste Package Department's (WPD) design methods, as documented in ''Waste Package Design Methodology Report'' (CRWMS M&O [Civilian Radioactive Waste Management System Management and Operating Contractor] 2000a). The DHLW disposal container is intended for disposal of commercial high-level waste (HLW) and DHLW (including immobilized plutonium waste forms), placed within disposable canisters. The U.S. Department of Energy (DOE)-managed spent nuclear fuel (SNF) in disposable canisters may also be placed in a DHLW disposal container along with HLW forms. The objective of this analysis is to demonstrate that the DHLW disposal container/waste package satisfies the project requirements, as embodied in Defense High Level Waste Disposal Container System Description Document (SDD) (CRWMS M&O 1999a), and additional criteria, as identified in Waste Package Design Sensitivity Report (CRWMS M&Q 2000b, Table 4). The analysis briefly describes the analytical methods appropriate for the design of the DHLW disposal contained waste package, and summarizes the results of the calculations that illustrate the analytical methods. However, the analysis is limited to the calculations selected for the DHLW disposal container in support of the Site Recommendation (SR) (CRWMS M&O 2000b, Section 7). The scope of this analysis is restricted to the design of the codisposal waste package of the Savannah River Site (SRS) DHLW glass canisters and the Training, Research, Isotopes General Atomics (TRIGA) SNF loaded in a short 18-in.-outer diameter (OD) DOE standardized SNF canister. This waste package is representative of the waste packages that consist of the DHLW disposal container, the DHLW/HLW glass canisters, and the DOE-managed SNF in disposable

  4. Erosion of quantitative host resistance in the apple × Venturia inaequalis pathosystem

    NARCIS (Netherlands)

    Caffier, V.; Lasserre-Zuber, P.; Giraud, M.; Lascostes, M.; Sievenard, R.; LeMarquand, A.; Weg, van de W.E.; Expert, P.; Denancé, C.

    2014-01-01

    Theoretical approaches predict that host quantitative resistance selects for pathogens with a high level of pathogenicity, leading to erosion of the resistance. This process of erosion has, however, rarely been experimentally demonstrated. To investigate the erosion of apple quantitative resistance

  5. Closure development for high-level nuclear waste containers for the tuff repository; Phase 1, Final report

    Energy Technology Data Exchange (ETDEWEB)

    Robitz, E.S. Jr.; McAninch, M.D. Jr.; Edmonds, D.P. [Babcock and Wilcox Co., Lynchburg, VA (USA). Nuclear Power Div.]|[Babcock and Wilcox Co., Alliance, OH (USA). Research and Development Div.

    1990-09-01

    This report summarizes Phase 1 activities for closure development of the high-level nuclear waste package task for the tuff repository. Work was conducted under U.S. Department of Energy (DOE) Contract 9172105, administered through the Lawrence Livermore National Laboratory (LLNL), as part of the Yucca Mountain Project (YMP), funded through the DOE Office of Civilian Radioactive Waste Management (OCRWM). The goal of this phase was to select five closure processes for further evaluation in later phases of the program. A decision tree methodology was utilized to perform an objective evaluation of 15 potential closure processes. Information was gathered via a literature survey, industrial contacts, and discussions with project team members, other experts in the field, and the LLNL waste package task staff. The five processes selected were friction welding, electron beam welding, laser beam welding, gas tungsten arc welding, and plasma arc welding. These are felt to represent the best combination of weldment material properties and process performance in a remote, radioactive environment. Conceptual designs have been generated for these processes to illustrate how they would be implemented in practice. Homopolar resistance welding was included in the Phase 1 analysis, and developments in this process will be monitored via literature in Phases 2 and 3. Work was conducted in accordance with the YMP Quality Assurance Program. 223 refs., 20 figs., 9 tabs.

  6. Tolerance of spermatogonia to oxidative stress is due to high levels of Zn and Cu/Zn superoxide dismutase.

    Directory of Open Access Journals (Sweden)

    Fritzie T Celino

    Full Text Available BACKGROUND: Spermatogonia are highly tolerant to reactive oxygen species (ROS attack while advanced-stage germ cells such as spermatozoa are much more susceptible, but the precise reason for this variation in ROS tolerance remains unknown. METHODOLOGY/PRINCIPAL FINDINGS: Using the Japanese eel testicular culture system that enables a complete spermatogenesis in vitro, we report that advanced-stage germ cells undergo intense apoptosis and exhibit strong signal for 8-hydroxy-2'-deoxyguanosine, an oxidative DNA damage marker, upon exposure to hypoxanthine-generated ROS while spermatogonia remain unaltered. Activity assay of antioxidant enzyme, superoxide dismutase (SOD and Western blot analysis using an anti-Copper/Zinc (Cu/Zn SOD antibody showed a high SOD activity and Cu/Zn SOD protein concentration during early spermatogenesis. Immunohistochemistry showed a strong expression for Cu/Zn SOD in spermatogonia but weak expression in advanced-stage germ cells. Zn deficiency reduced activity of the recombinant eel Cu/Zn SOD protein. Cu/Zn SOD siRNA decreased Cu/Zn SOD expression in spermatogonia and led to increased oxidative damage. CONCLUSIONS/SIGNIFICANCE: These data indicate that the presence of high levels of Cu/Zn SOD and Zn render spermatogonia resistant to ROS, and consequently protected from oxidative stress. These findings provide the biochemical basis for the high tolerance of spermatogonia to oxidative stress.

  7. FTIR and Mössbauer spectroscopic study of sodium–aluminum–iron phosphate glassy materials for high level waste immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Stefanovsky, S.V., E-mail: serge.stefanovsky@yandex.ru [Frumkin Institute of Physical Chemistry and Electrochemistry of the Russian Academy of Sciences, Laboratory of Radioecology and Radiation Problems, Moscow (Russian Federation); Stefanovsky, O.I. [Frumkin Institute of Physical Chemistry and Electrochemistry of the Russian Academy of Sciences, Laboratory of Radioecology and Radiation Problems, Moscow (Russian Federation); Remizov, M.B.; Belanova, E.A.; Kozlov, P.V. [FSUE PA Mayak, Central Plant Laboratory, Ozersk, Chelyabinsk Reg. (Russian Federation); Glazkova, Ya.S.; Sobolev, A.V.; Presniakov, I.A. [Lomonosov Moscow State University, Department of Radiochemistry (Russian Federation); Kalmykov, S.N. [Frumkin Institute of Physical Chemistry and Electrochemistry of the Russian Academy of Sciences, Laboratory of Radioecology and Radiation Problems, Moscow (Russian Federation); Lomonosov Moscow State University, Department of Radiochemistry (Russian Federation); Vernadsky Institute of Geochemistry and Analytical Chemistry of the Russian Academy of Sciences, Laboratory of Radiochemistry, Moscow (Russian Federation); Myasoedov, B.F. [Frumkin Institute of Physical Chemistry and Electrochemistry of the Russian Academy of Sciences, Laboratory of Radioecology and Radiation Problems, Moscow (Russian Federation); Vernadsky Institute of Geochemistry and Analytical Chemistry of the Russian Academy of Sciences, Laboratory of Radiochemistry, Moscow (Russian Federation)

    2015-11-15

    Complex sodium-aluminum-iron phosphate glassy materials with various Al{sub 2}O{sub 3} to Fe{sub 2}O{sub 3} ratio containing high level waste (HLW) surrogate were characterized by X-ray diffraction and scanning electron microscopy and studied in details by Fourier transform infrared (FTIR) spectroscopy. The samples with high Al{sub 2}O{sub 3} content and not containing Fe{sub 2}O{sub 3} were predominantly amorphous but subjected to devitrification under annealing. Addition of B{sub 2}O{sub 3} and partial Fe{sub 2}O{sub 3} substitution for Al{sub 2}O{sub 3} in the materials increases their resistance to devitrification whereas further substitution and NiO incorporation significantly increase the tendency to devitrification. FTIR spectra demonstrate changes in the structure of glassy materials caused by both structural variations in the anionic motif and occurrence of crystalline phases in the materials. According to Mössbauer spectroscopy data, iron in the glassy samples is present as octahedrally coordinated Fe{sup 3+} ions while in the partly devitrified samples iron is partitioned among vitreous and crystalline phases entering the vitreous phase mainly as Fe{sup 3+}O{sub 6} units and crystalline phases as major Fe{sup 3+} and minor Fe{sup 2+} ions in a magnetically ordered state and participating in a “fast” electronic exchange.

  8. Cooperative effects of cation size and variable coordination modes of Te(4+) on the frameworks of new alkali metal indium tellurites, NaIn(TeO3)2, KIn(TeO3)2, RbInTe3O8, and CsInTe3O8.

    Science.gov (United States)

    Bae, Su-Whan; Kim, Choong-Yeol; Lee, Dong Woo; Ok, Kang Min

    2014-10-20

    Four new alkali metal indium tellurites, NaIn(TeO3)2, KIn(TeO3)2, RbInTe3O8, and CsInTe3O8, have been prepared through hydrothermal and solid state synthesis reactions using corresponding alkali metal carbonates, In2O3 [or In(NO3)3·xH2O], and TeO2. The structures of the reported materials have been determined by powder and single crystal X-ray diffraction. The mixed indium tellurites reveal a rich structural chemistry with different channel structures. NaIn(TeO3)2 shows 8-membered rings, whereas stoichiometrically similar KIn(TeO3)2 exhibits both 8- and 12-membered rings in the frameworks. Isostructural RbInTe3O8 and CsInTe3O8 reveal three-dimensional frameworks consisting of InO6, TeO3, and TeO4 groups. Close structural examination suggests that the alkali metal cation size and variable coordination modes of Te(4+) cations cooperatively influence the framework geometries of the new mixed metal tellurites. Detailed characterizations including spectroscopic, elemental, and thermal analyses are introduced. Local dipole moments and out-of-center distortions for the constituent polyhedra are also reported.

  9. Internal curvature signal and noise in low- and high-level vision

    Science.gov (United States)

    Grabowecky, Marcia; Kim, Yee Joon; Suzuki, Satoru

    2011-01-01

    How does internal processing contribute to visual pattern perception? By modeling visual search performance, we estimated internal signal and noise relevant to perception of curvature, a basic feature important for encoding of three-dimensional surfaces and objects. We used isolated, sparse, crowded, and face contexts to determine how internal curvature signal and noise depended on image crowding, lateral feature interactions, and level of pattern processing. Observers reported the curvature of a briefly flashed segment, which was presented alone (without lateral interaction) or among multiple straight segments (with lateral interaction). Each segment was presented with no context (engaging low-to-intermediate-level curvature processing), embedded within a face context as the mouth (engaging high-level face processing), or embedded within an inverted-scrambled-face context as a control for crowding. Using a simple, biologically plausible model of curvature perception, we estimated internal curvature signal and noise as the mean and standard deviation, respectively, of the Gaussian-distributed population activity of local curvature-tuned channels that best simulated behavioral curvature responses. Internal noise was increased by crowding but not by face context (irrespective of lateral interactions), suggesting prevention of noise accumulation in high-level pattern processing. In contrast, internal curvature signal was unaffected by crowding but modulated by lateral interactions. Lateral interactions (with straight segments) increased curvature signal when no contextual elements were added, but equivalent interactions reduced curvature signal when each segment was presented within a face. These opposing effects of lateral interactions are consistent with the phenomena of local-feature contrast in low-level processing and global-feature averaging in high-level processing. PMID:21209356

  10. High level of serum AFP is an independent negative prognostic factor in gastric cancer.

    Science.gov (United States)

    Chen, Yueguang; Qu, Hui; Jian, Mi; Sun, Guorui; He, Qingsi

    2015-11-11

    Gastric cancer with a high level of serum alpha fetoprotein (AFP) is uncommon and has unique clinicopathological features and a poorer prognosis. The aim of this research was to elucidate the clinicopathological and prognostic features of gastric cancer with a high level of AFP. The sera from 1,286 patients with gastric cancer treated at Qilu Hospital of Shandong University from January 2004 to December 2008 were analyzed preoperatively for AFP, CEA and CA19-9 levels after excluding active or chronic hepatitis, liver cirrhosis and hepatocellular carcinoma as well as preoperative distant metastasis. Patients were divided into 2 groups: 86 serum AFP-positive patients and 1,200 serum AFP-negative patients according to a cutoff of 20 ng/mL. The clinicopathological features and prognostic factors were compared between the groups. A higher incidence of serosal invasion, lymph node metastasis and liver metastasis and poorer prognosis was observed in the AFP-positive group compared with the AFP-negative group (all p<0.05). Serum AFP showed the highest specificity (93.66%) and diagnostic accuracy (92.38%) for predicting liver metastasis among the 3 tumor markers examined. Multivariate survival analysis revealed that AFP positivity was an independent prognostic factor in all 1,286 gastric cancer patients. The prognosis of AFP-positive gastric cancer was poorer than that of AFP-negative gastric cancer (p<0.05). A high level of serum AFP is an independent prognostic factor in gastric cancer and can be used for evaluating the prognosis of gastric cancers whether in the presence or absence of liver metastasis.

  11. Application of new technologies for characterization of Hanford Site high-level waste

    Energy Technology Data Exchange (ETDEWEB)

    Winters, W.I.

    1998-02-03

    To support remediation of Hanford Site high-level radioactive waste tanks, new chemical and physical measurement technologies must be developed and deployed. This is a major task of the Chemistry Analysis Technology Support (CATS) group of the Hanford Corporation. New measurement methods are required for efficient and economical resolution of tank waste safety, waste retrieval, and disposal issues. These development and deployment activities are performed in cooperation with Waste Management Federal Services of Hanford, Inc. This paper provides an overview of current analytical technologies in progress. The high-level waste at the Hanford Site is chemically complex because of the numerous processes used in past nuclear fuel reprocessing there, and a variety of technologies is required for effective characterization. Programmatic and laboratory operational needs drive the selection of new technologies for characterizing Hanford Site high-level waste, and these technologies are developed for deployment in laboratories, hot cells or in the field. New physical methods, such as the propagating reactive systems screening tool (PRSST) to measure the potential for self-propagating reactions in stored wastes, are being implemented. Technology for sampling and measuring gases trapped within the waste matrix is being used to evaluate flammability hazards associated with gas releases from stored wastes. Application of new inductively coupled plasma and laser ablation mass spectrometry systems at the Hanford Site`s 222-S Laboratory will be described. A Raman spectroscopy probe mounted in a cone penetrometer to measure oxyanions in wastes or soils will be described. The Hanford Site has used large volumes of organic complexants and acids in processing waste, and capillary zone electrophoresis (CZE) methods have been developed for determining several of the major organic components in complex waste tank matrices. The principles involved, system installation, and results from

  12. Tank waste remediation system high-level waste feed processability assessment report

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, S.L. [Westinghouse Hanford Co., Richland, WA (United States); Kim, D.S. [Pacific Northwest Lab., Richland, WA (United States)

    1994-12-01

    This study evaluates the effect of feed composition on the performance of the high-level vitrification process. It is assumed in this study that the tank wastes are retrieved and blended by tank farms, producing 12 different blends from the single-shell tank farms, two blends of double-shell tank waste, and a separately defined all-tank blend. This blending scenario was chosen only for evaluating the impact of composition on the volume of high- level waste glass produced. Special glass compositions were formulated for each waste blend based on glass property models and the properties of similar glasses. These glasses were formulated to meet the applicable viscosity, electrical conductivity, and liquidus temperature constraints for the identified candidate melters. Candidate melters in this study include the low-temperature stirred melter, which operates at 1050{degrees}C; the reference Hanford Waste Vitrification Plant liquid-fed ceramic melter, which operates at 1150{degrees}C; and the high-temperature, joule-heated melter and the cold-crucible melter, which operate over a temperature range of 1150{degrees}C to 1400{degrees}C. In the most conservative case, it is estimated that 61,000 MT of glass will be produced if the Site`s high-level wastes are retrieved by tank farms and processed in the reference joule-heated melter. If an all-tank blend was processed under the same conditions, the reference melter would produce 21,250 MT of glass. If cross-tank blending were used, it is anticipated that $2.0 billion could be saved in repository disposal costs (based on an average disposal cost of $217,000 per canister) by blending the S, SX, B, and T Tank Farm wastes with other wastes prior to vitrification. General blending among all the tank farms is expected to produce great potential benefit.

  13. Reference design and operations for deep borehole disposal of high-level radioactive waste.

    Energy Technology Data Exchange (ETDEWEB)

    Herrick, Courtney Grant; Brady, Patrick Vane; Pye, Steven; Arnold, Bill Walter; Finger, John Travis; Bauer, Stephen J.

    2011-10-01

    A reference design and operational procedures for the disposal of high-level radioactive waste in deep boreholes have been developed and documented. The design and operations are feasible with currently available technology and meet existing safety and anticipated regulatory requirements. Objectives of the reference design include providing a baseline for more detailed technical analyses of system performance and serving as a basis for comparing design alternatives. Numerous factors suggest that deep borehole disposal of high-level radioactive waste is inherently safe. Several lines of evidence indicate that groundwater at depths of several kilometers in continental crystalline basement rocks has long residence times and low velocity. High salinity fluids have limited potential for vertical flow because of density stratification and prevent colloidal transport of radionuclides. Geochemically reducing conditions in the deep subsurface limit the solubility and enhance the retardation of key radionuclides. A non-technical advantage that the deep borehole concept may offer over a repository concept is that of facilitating incremental construction and loading at multiple perhaps regional locations. The disposal borehole would be drilled to a depth of 5,000 m using a telescoping design and would be logged and tested prior to waste emplacement. Waste canisters would be constructed of carbon steel, sealed by welds, and connected into canister strings with high-strength connections. Waste canister strings of about 200 m length would be emplaced in the lower 2,000 m of the fully cased borehole and be separated by bridge and cement plugs. Sealing of the upper part of the borehole would be done with a series of compacted bentonite seals, cement plugs, cement seals, cement plus crushed rock backfill, and bridge plugs. Elements of the reference design meet technical requirements defined in the study. Testing and operational safety assurance requirements are also defined. Overall

  14. GPU-Based Tracking Algorithms for the ATLAS High-Level Trigger

    CERN Document Server

    Emeliyanov, D; The ATLAS collaboration

    2012-01-01

    GPU-accelerated event processing is one of the possible options for the ATLAS High-Level Trigger (HLT) upgrade for higher LHC luminosity. This poster presents data preparation and track finding algorithms specifically designed to run on a GPU using a “client-server” solution for hybrid CPU/GPU event processing and integration of the GPU algorithms into existing ATLAS HLT software. The resulting speed-up of event processing times obtained with high-luminosity simulated data is presented and discussed.

  15. High-level waste borosilicate glass: A compendium of corrosion characteristics. Volume 3

    Energy Technology Data Exchange (ETDEWEB)

    Cunnane, J.C. [comp.; Bates, J.K.; Bradley, C.R. [Argonne National Lab., IL (United States)] [and others

    1994-03-01

    The objective of this document is to summarize scientific information pertinent to evaluating the extent to which high-level waste borosilicate glass corrosion and the associated radionuclide release processes are understood for the range of environmental conditions to which waste glass may be exposed in service. Alteration processes occurring within the bulk of the glass (e.g., devitrification and radiation-induced changes) are discussed insofar as they affect glass corrosion. Volume III contains a bibliography of glass corrosion studies, including studies that are not cited in Volumes I and II.

  16. Crystal accumulation in the Hanford Waste Treatment Plant high level waste melter: Summary of 2017 experiments

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Fowley, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2018-01-11

    A full-scale, transparent mock-up of the Hanford Tank Waste Treatment and Immobilization Project High Level Waste glass melter riser and pour spout has been constructed to allow for testing with visual feedback of particle settling, accumulation, and resuspension when operating with a controlled fraction of crystals in the glass melt. Room temperature operation with silicone oil and magnetite particles simulating molten glass and spinel crystals, respectively, allows for direct observation of flow patterns and settling patterns. The fluid and particle mixture is recycled within the system for each test.

  17. Phylogeographic reconstruction of a bacterial species with high levels of lateral gene transfer

    Directory of Open Access Journals (Sweden)

    Kaul Rajinder

    2009-11-01

    Full Text Available Abstract Background Phylogeographic reconstruction of some bacterial populations is hindered by low diversity coupled with high levels of lateral gene transfer. A comparison of recombination levels and diversity at seven housekeeping genes for eleven bacterial species, most of which are commonly cited as having high levels of lateral gene transfer shows that the relative contributions of homologous recombination versus mutation for Burkholderia pseudomallei is over two times higher than for Streptococcus pneumoniae and is thus the highest value yet reported in bacteria. Despite the potential for homologous recombination to increase diversity, B. pseudomallei exhibits a relative lack of diversity at these loci. In these situations, whole genome genotyping of orthologous shared single nucleotide polymorphism loci, discovered using next generation sequencing technologies, can provide very large data sets capable of estimating core phylogenetic relationships. We compared and searched 43 whole genome sequences of B. pseudomallei and its closest relatives for single nucleotide polymorphisms in orthologous shared regions to use in phylogenetic reconstruction. Results Bayesian phylogenetic analyses of >14,000 single nucleotide polymorphisms yielded completely resolved trees for these 43 strains with high levels of statistical support. These results enable a better understanding of a separate analysis of population differentiation among >1,700 B. pseudomallei isolates as defined by sequence data from seven housekeeping genes. We analyzed this larger data set for population structure and allele sharing that can be attributed to lateral gene transfer. Our results suggest that despite an almost panmictic population, we can detect two distinct populations of B. pseudomallei that conform to biogeographic patterns found in many plant and animal species. That is, separation along Wallace's Line, a biogeographic boundary between Southeast Asia and Australia

  18. Maintenance Free and Sustainable High-Level Control in Cement and Mining Industry

    DEFF Research Database (Denmark)

    Hansen, Ole Fink

    2009-01-01

    recognized. Therefore, the payback time may be less than one year. It is common however, that the systems are disabled only a few months after commissioning because the process has changed in such a way that it does no longer matching the systems’ tuning. The cause of this can be raw materials changing, wear...... or eliminate the amount of resources needed to keep a high performance. Current high-level control algorithms are sophisticated and complex software. An analysis of such algorithms shows that only 10% of the source code can be considered implementation of control theory. The remaining 90% handles other tasks...

  19. Scaphoid Stress Fracture in High-Level Gymnast: A Case Report

    Directory of Open Access Journals (Sweden)

    J. C. Nakamoto

    2011-01-01

    Full Text Available We present the case of an 18-year-old high-level gymnast who sustained a stress fracture of the scaphoid associated with a distal radial epiphysiolysis. Clinical evaluation demonstrated decreased range of motion of the affected wrist and insidious pain on the snuffbox and tenderness on the distal radial physis. He was submitted to surgical treatment with scaphoid percutaneous fixation and radial styloid process in situ fixation. Clinical features improved, and he got back to competition 6 months after surgery without symptoms and with complete range of motion.

  20. Workshop on the role of natural analogs in geologic disposal of high-level nuclear waste

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, W.M. [Center for Nuclear Waste Regulations Analyses, San Antonio, TX (United States); Kovach, L.A. [Nuclear Regulatory Commission, Washington, DC (United States)

    1995-09-01

    A workshop on the Role of Natural Analogs in Geologic Disposal of High-Level Nuclear Waste (HLW) was held in San Antonio, Texas, on July 22-25, 1991. It was sponsored by the US Nuclear Regulatory Commission (NRC) and the Center for Nuclear Waste Regulatory Analyses (CNWRA). Invitations to the workshop were extended to a large number of individuals with a variety of technical and professional interests related to geologic disposal of nuclear waste and natural analog studies. The objective of the workshop was to examine the role of natural analog studies in performance assessment, site characterization, and prioritization of research related to geologic disposal of HLW.