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Sample records for exhibits high-level resistance

  1. Transgenic rice plants expressing the snowdrop lectin gene (gna) exhibit high-level resistance to the whitebacked planthopper (Sogatella furcifera).

    PubMed

    Nagadhara, D; Ramesh, S; Pasalu, I C; Rao, Y Kondala; Sarma, N P; Reddy, V D; Rao, K V

    2004-11-01

    Transgenic rice plants, expressing snowdrop lectin [Galanthus nivalis agglutinin (GNA)], obtained by Agrobacterium-mediated genetic transformation, were evaluated for resistance against the insect, the whitebacked planthopper (WBPH). The transgene gna was driven by the phloem-specific, rice-sucrose synthase promoter RSs1, and the bar was driven by the CaMV 35S promoter. In our previous study, the transgenic status of these lines was confirmed by Southern, Northern and Western blot analyses. Both the transgenes, gna and bar, were stably inherited and co-segregated into progenies in T1 to T5 generations. Insect bioassays on transgenic plants revealed the potent entomotoxic effects of GNA on the WBPH. Also, significant decreases were observed in the survival, development and fecundity of the insects fed on transgenic plants. Furthermore, intact GNA was detected in the total proteins of WBPHs fed on these plants. Western blot analysis revealed stable and consistent expression of GNA throughout the growth and development of transgenic plants. Transgenic lines expressing GNA exhibited high-level resistance against the WBPH. As reported earlier, these transgenics also showed substantial resistance against the brown planthopper and green leafhopper.

  2. Synergy characterization for Enterococcus faecalis strains displaying moderately high-level gentamicin and streptomycin resistance.

    PubMed Central

    Bantar, C E; Micucci, M; Fernandez Canigia, L; Smayevsky, J; Bianchini, H M

    1993-01-01

    Synergy of 14 Enterococcus faecalis strains displaying moderately high-level aminoglycoside resistance (MICs, 500 and 256 to 1,000 micrograms/ml for gentamicin and streptomycin, respectively) was characterized by time-kill studies. All strains proved resistant to penicillin plus the respective aminoglycoside. Strains with moderately high-level aminoglycoside resistance should be considered to exhibit high-level resistance in severe infections. PMID:8349776

  3. Synergy characterization for Enterococcus faecalis strains displaying moderately high-level gentamicin and streptomycin resistance.

    PubMed

    Bantar, C E; Micucci, M; Fernandez Canigia, L; Smayevsky, J; Bianchini, H M

    1993-07-01

    Synergy of 14 Enterococcus faecalis strains displaying moderately high-level aminoglycoside resistance (MICs, 500 and 256 to 1,000 micrograms/ml for gentamicin and streptomycin, respectively) was characterized by time-kill studies. All strains proved resistant to penicillin plus the respective aminoglycoside. Strains with moderately high-level aminoglycoside resistance should be considered to exhibit high-level resistance in severe infections.

  4. Unique Flap Conformation in an HIV-1 Protease with High-Level Darunavir Resistance.

    PubMed

    Nakashima, Masaaki; Ode, Hirotaka; Suzuki, Koji; Fujino, Masayuki; Maejima, Masami; Kimura, Yuki; Masaoka, Takashi; Hattori, Junko; Matsuda, Masakazu; Hachiya, Atsuko; Yokomaku, Yoshiyuki; Suzuki, Atsuo; Watanabe, Nobuhisa; Sugiura, Wataru; Iwatani, Yasumasa

    2016-01-01

    Darunavir (DRV) is one of the most powerful protease inhibitors (PIs) 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. PMID:26870021

  5. Unique Flap Conformation in an HIV-1 Protease with High-Level Darunavir Resistance

    PubMed Central

    Nakashima, Masaaki; Ode, Hirotaka; Suzuki, Koji; Fujino, Masayuki; Maejima, Masami; Kimura, Yuki; Masaoka, Takashi; Hattori, Junko; Matsuda, Masakazu; Hachiya, Atsuko; Yokomaku, Yoshiyuki; Suzuki, Atsuo; Watanabe, Nobuhisa; Sugiura, Wataru; Iwatani, Yasumasa

    2016-01-01

    Darunavir (DRV) is one of the most powerful protease inhibitors (PIs) 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. PMID:26870021

  6. Superconductive microstrip exhibiting negative differential resistivity

    DOEpatents

    Huebener, R.P.; Gallus, D.E.

    1975-10-28

    A device capable of exhibiting negative differential electrical resistivity over a range of values of current and voltage is formed by vapor- depositing a thin layer of a material capable of exhibiting superconductivity on an insulating substrate, establishing electrical connections at opposite ends of the deposited strip, and cooling the alloy into its superconducting range. The device will exhibit negative differential resistivity when biased in the current- induced resistive state.

  7. Genetic relatedness of high-level aminoglycoside-resistant enterococci isolated from poultry carcasses.

    PubMed

    Jackson, Charlene R; Fedorka-Cray, Paula J; Barrett, John B; Ladely, Scott R

    2004-01-01

    Approximately 46% (75/162) or poultry enterococci collected between 1999 and 2000 exhibited high-level resistance to gentamicin (minimum inhibitory concentration [MIC] > or = 500 microg/ml), kanamycin (MIC > or = 500 microg/ml), or streptomycin (MIC > or = 1000 microg/ml). Forty-one percent of the isolates were resistant to kanamycin (n = 67), whereas 23% and 19% were resistant to genramicin (n = 37) and streptomycin (n = 31), respectively. The predominant species identified was Enterococcus faecium (n = 105), followed by Enterococcus faecalis (n = 40) and Enterococcus durans (n = 8). Using polymerase chain reaction, the isolates were examined for the presence of 10 aminoglycoside resistance genes [ant(6)-Ia, ant(9)-Ia, ant(4')-Ia, aph(3')-IIIa, aph(2")-Ib, aph(2")-Ic, aph(2")-Id, aac(6')-Ie-aph(2")-Ia, and aac(6')-Ii]. Five aminoglycoside resistance genes were detected, most frequently aac(6')-Ii and ant(6)-Ia from E. faecium. Seven E. faecalis isolates resistant to gentamicin, kanamycin, or streptomycin were negative for all genes tested, indicating that additional resistance genes may exist. Phylogenetic analysis revealed that the isolates were genetically different with little clonality. These data indicate that enterococci from poultry are diverse and contain potentially unidentified aminoglycoside resistance genes.

  8. Multiple resistance mechanisms among Aspergillus fumigatus mutants with high-level resistance to itraconazole.

    PubMed

    Nascimento, Adriana M; Goldman, Gustavo H; Park, Steven; Marras, Salvatore A E; Delmas, Guillaume; Oza, Uma; Lolans, Karen; Dudley, Michael N; Mann, Paul A; Perlin, David S

    2003-05-01

    A collection of Aspergillus fumigatus mutants highly resistant to itraconazole (RIT) at 100 micro g ml(-1) were selected in vitro (following UV irradiation as a preliminary step) to investigate mechanisms of drug resistance in this clinically important pathogen. Eight of the RIT mutants were found to have a mutation at Gly54 (G54E, -K, or -R) in the azole target gene CYP51A. Primers designed for highly conserved regions of multidrug resistance (MDR) pumps were used in reverse transcriptase PCR amplification reactions to identify novel genes encoding potential MDR efflux pumps in A. fumigatus. Two genes, AfuMDR3 and AfuMDR4, showed prominent changes in expression levels in many RIT mutants and were characterized in more detail. Analysis of the deduced amino acid sequence encoded by AfuMDR3 revealed high similarity to major facilitator superfamily transporters, while AfuMDR4 was a typical member of the ATP-binding cassette superfamily. Real-time quantitative PCR with molecular beacon probes was used to assess expression levels of AfuMDR3 and AfuMDR4. Most RIT mutants showed either constitutive high-level expression of both genes or induction of expression upon exposure to itraconazole. Our results suggest that overexpression of one or both of these newly identified drug efflux pump genes of A. fumigatus and/or selection of drug target site mutations are linked to high-level itraconazole resistance and are mechanistic considerations for the emergence of clinical resistance to itraconazole.

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

    EPA Science Inventory

    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...

  10. In vitro effect of levofloxacin and vancomycin combination against high level aminoglycoside-resistant enterococci.

    PubMed

    Erdem, Ilknur; Cicek-Senturk, Gonul; Yucesoy-Dede, Behiye; Yuksel-Kocdogan, Funda; Yuksel, Saim; Karagul, Emin

    2004-01-01

    The in vitro effects of levofloxacin and vancomycin in combination were evaluated against high level aminoglycoside-resistant (HLAR) enterococci using chequerboard and time-kill curve techniques. We examined 28 strains of enterococci comprising 17 Enterococcus faecalis, 10 E. faecium and one E. durans. The combination of vancomycin and levofloxacin had indifferent activity against all isolates according to chequerboard microdilution method, but was synergistic for two isolates, one E. faecium and one E. faecalis, using the time-kill curve method. Both strains were levofloxacin resistant and had high level aminoglycoside resistance to gentamicin and streptomycin. Antagonism was not detected in any strain. The results of this study suggested that the combination of vancomycin with levofloxacin does not often show synergistic effect against high level aminoglycoside-resistant enterococci.

  11. Molecular Characterization of High-Level Mupirocin Resistance in Staphylococcus pseudintermedius

    PubMed Central

    Pérez-Roth, Eduardo; Pintarić, Selma; Šeol Martinec, Branka

    2013-01-01

    The genetic analysis of high-level mupirocin resistance (Hi-Mupr) in a Staphylococcus pseudintermedius isolate from a dog is presented. The Hi-Mupr ileS2 gene flanked by a novel rearrangement of directly repeated insertion sequence IS257 elements was located, together with the aminoglycoside resistance aacA-aphD determinant, on a conjugative plasmid related to the pSK41/pGO1 family plasmids. PMID:23269741

  12. High-level azithromycin-resistant Neisseria gonorrhoeae clinical isolate in France, March 2014.

    PubMed

    Bercot, B; Belkacem, A; Goubard, A; Mougari, F; Sednaoui, P; La Ruche, G; Cambau, E

    2014-11-06

    We report the first case in France of a high-level azithromycin-resistant Neisseria gonorrhoeae (minimum inhibitory concentration (MIC) = 96 mg/L) assigned to MLST7363 (NG-MAST ST6360), also resistant to ciprofloxacin and tetracycline but susceptible to ceftriaxone. The patient was a 51 year-old heterosexual man who returned following 1g azithromycin monotherapy. Mechanisms of azithromycin resistance were a C2599T mutation in the four copies of the rrl gene and a novel mutation in the promoter of the mtrR gene.

  13. High-level azithromycin-resistant Neisseria gonorrhoeae clinical isolate in France, March 2014.

    PubMed

    Bercot, B; Belkacem, A; Goubard, A; Mougari, F; Sednaoui, P; La Ruche, G; Cambau, E

    2014-01-01

    We report the first case in France of a high-level azithromycin-resistant Neisseria gonorrhoeae (minimum inhibitory concentration (MIC) = 96 mg/L) assigned to MLST7363 (NG-MAST ST6360), also resistant to ciprofloxacin and tetracycline but susceptible to ceftriaxone. The patient was a 51 year-old heterosexual man who returned following 1g azithromycin monotherapy. Mechanisms of azithromycin resistance were a C2599T mutation in the four copies of the rrl gene and a novel mutation in the promoter of the mtrR gene. PMID:25394255

  14. Isolation of High Level Macrolide Resistant Bordetella pertussis Without Transition Mutation at Domain V in Iran

    PubMed Central

    Mirzaei, Bahman; Bameri, Zakaria; Babaei, Ryhane; Shahcheraghi, Fereshteh

    2015-01-01

    Background: Bordetella pertussis, as a causative agent of whooping cough, due to the annual rise y of infection cases, failure of prophylaxis and treatment by macrolides, is considered as the new concern in the health care system. Objectives: The main objective of this study was the determination of single nucleotide polymorphisms (SNPs) at domain V, as the main binding site for macrolides, following the identification of high level macrolides resistant B. pertussis. Materials and Methods: Following the identification of 11 recovered B. pertussis isolates, from a total of 1084 nasopharyngeal swabs, by using the biochemical and molecular methods, the activities of erythromycin, azithromycin and clarithromycin antibiotics against the recovered isolates were examined. Subsequently, A-G transition mutations in domain V were analyzed by molecular techniques, such as Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) and sequencing. Results: After susceptibility testing, one strain was detected as a high level macrolide resistant B. pertussis (Erythromycin = 128 μg/mL, Clarithromycin > 256 μg/mL). After sequencing and PCR-RFLP methods, transition mutations in positions 2047 and 2058 of the mentioned domain were not observed. Conclusions: Although previous studies have shown that A-G transition mutations in 23 SrRNA gene (domain V) are the main reason for the occurrence of high level macrolides resistance in B. pertussis, however, the mentioned single nucleotide polymorphisms (SNPs) have not been detected in our resistant strain. This is the first report of high level macrolide resistant B. pertussis, without SNPs in domain V, in Iran. PMID:26396713

  15. High level resistance against rhizomania disease by simultaneously integrating two distinct defense mechanisms.

    PubMed

    Pavli, Ourania I; Tampakaki, Anastasia P; Skaracis, George N

    2012-01-01

    With the aim of achieving durable resistance against rhizomania disease of sugar beet, the employment of different sources of resistance to Beet necrotic yellow vein virus was pursued. To this purpose, Nicotiana benthamiana transgenic plants that simultaneously produce dsRNA originating from a conserved region of the BNYVV replicase gene and the HrpZ(Psph) protein in a secreted form (SP/HrpZ(Psph)) were produced. The integration and expression of both transgenes as well as proper production of the harpin protein were verified in all primary transformants and selfed progeny (T1, T2). Transgenic resistance was assessed by BNYVV-challenge inoculation on T2 progeny by scoring disease symptoms and DAS-ELISA at 20 and 30 dpi. Transgenic lines possessing single transformation events for both transgenes as well as wild type plants were included in inoculation experiments. Transgenic plants were highly resistant to virus infection, whereas in some cases immunity was achieved. In all cases, the resistant phenotype of transgenic plants carrying both transgenes was superior in comparison with the ones carrying a single transgene. Collectively, our findings demonstrate, for a first time, that the combination of two entirely different resistance mechanisms provide high level resistance or even immunity against the virus. Such a novel approach is anticipated to prevent a rapid virus adaptation that could potentially lead to the emergence of isolates with resistance breaking properties.

  16. High level resistance against rhizomania disease by simultaneously integrating two distinct defense mechanisms.

    PubMed

    Pavli, Ourania I; Tampakaki, Anastasia P; Skaracis, George N

    2012-01-01

    With the aim of achieving durable resistance against rhizomania disease of sugar beet, the employment of different sources of resistance to Beet necrotic yellow vein virus was pursued. To this purpose, Nicotiana benthamiana transgenic plants that simultaneously produce dsRNA originating from a conserved region of the BNYVV replicase gene and the HrpZ(Psph) protein in a secreted form (SP/HrpZ(Psph)) were produced. The integration and expression of both transgenes as well as proper production of the harpin protein were verified in all primary transformants and selfed progeny (T1, T2). Transgenic resistance was assessed by BNYVV-challenge inoculation on T2 progeny by scoring disease symptoms and DAS-ELISA at 20 and 30 dpi. Transgenic lines possessing single transformation events for both transgenes as well as wild type plants were included in inoculation experiments. Transgenic plants were highly resistant to virus infection, whereas in some cases immunity was achieved. In all cases, the resistant phenotype of transgenic plants carrying both transgenes was superior in comparison with the ones carrying a single transgene. Collectively, our findings demonstrate, for a first time, that the combination of two entirely different resistance mechanisms provide high level resistance or even immunity against the virus. Such a novel approach is anticipated to prevent a rapid virus adaptation that could potentially lead to the emergence of isolates with resistance breaking properties. PMID:23284692

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    PubMed Central

    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

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

    PubMed

    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.

  20. Neisseria gonorrhoeae with high-level resistance to azithromycin: case report of the first isolate identified in the United States.

    PubMed

    Katz, Alan R; Komeya, Alan Y; Soge, Olusegun O; Kiaha, Mandy I; Lee, Maria Veneranda C; Wasserman, Glenn M; Maningas, Eloisa V; Whelen, A Christian; Kirkcaldy, Robert D; Shapiro, Steven J; Bolan, Gail A; Holmes, King K

    2012-03-01

    We report on the first Neisseria gonorrhoeae isolate in the United States identified with high-level resistance to azithromycin. This report discusses the epidemiologic case investigation, the molecular studies of resistance-associated mutations and N. gonorrhoeae multiantigen sequence typing, and challenges posed by emerging gonococcal antimicrobial resistance. PMID:22184617

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

    PubMed

    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.

  2. High level aminoglycoside resistance and distribution of aminoglycoside resistant genes among clinical isolates of Enterococcus species in Chennai, India.

    PubMed

    Padmasini, Elango; Padmaraj, R; Ramesh, S Srivani

    2014-01-01

    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.

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

    PubMed

    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.

  4. Fall armyworm and corn earworm resistance in the breeding crosses of maize inbreds with high levels of phytoalexins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order to develop maize germplasm with resistance to multiple insect pests and aflatoxin accumulation, a set of reciprocal breeding crosses was made using maize inbred lines with high levels of kauralexins or zealexins. The evaluation of the breeding crosses for insect resistance utilized the rand...

  5. High levels of multiresistance in quinolone resistant urinary tract isolates of Escherichia coli from Norway; a non clonal phenomen?

    PubMed Central

    2014-01-01

    Background The problem of emerging ciprofloxacin resistance is compounded by its frequent association with multiresistance, the reason for which is not fully understood. In this study we compare multiresistance, clonal similarities and phylogenetic group in urinary tract isolates of Escherichia coli sensitive and resistant to the quinolone antimicrobials nalidixic acid and ciprofloxacin. Results Quinolone resistant isolates were more resistant to non-quinolone antibiotics than sensitive isolates, with resistance to ampicillin, mecillinam, sulphonamide, trimethoprim, tetracycline, kanamycin and chloramphenicol significantly increased. Fifty-one percent of quinolone-resistant isolates were multiresistant. Although multiresistance was most prevalent (63%) in isolates showing high-level ciprofloxacin resistance, it was still highly prevalent (41%) in nalidixic acid resistant isolates with low-level ciprofloxacin resistance. Multiresistance was more frequent among singleton isolates (61%) than clonal isolates (40%) of quinolone resistant Escherichia coli. Ciprofloxacin resistance was associated with certain specific clones, among them the globally distributed clonal Group A. However, there was no significant difference in the overall degree of clonality between quinolone sensitive and resistant isolates. Ciprofloxacin resistance was positively associated with phylogroup D and negatively associated with phylogroup B2. This correlation was not associated with clonal isolates. Conclusion This study supports earlier findings of association between ciprofloxacin resistance and resistance to other antibiotics. The prevalence of multiresistance in quinolone-resistant isolates that have not yet developed high-level ciprofloxacin resistance suggest that multiresistance arises early in the development of quinolone resistance. This is consistent with exposure to quinolones causing quinolone resistance by mutations and mobilization of multiresistance elements by induction of the

  6. The mechanism of high-level carbapenem resistance in Klebsiella pneumoniae: underlying Ompk36-deficient strains represent a threat of emerging high-level carbapenem-resistant K. pneumoniae with IMP-1 β-lactamase production in Japan.

    PubMed

    Sho, Takehiko; Muratani, Tetsuro; Hamasuna, Ryoichi; Yakushiji, Hiroko; Fujimoto, Naohiro; Matsumoto, Tetsuro

    2013-08-01

    The mechanisms of high-level carbapenem resistance in Klebsiella pneumoniae isolated in Japan were investigated. High-level carbapenem-resistant K. pneumoniae Mkp4437 and a less carbapenem-sensitive K. pneumoniae strain, Mkp4365, were recovered from the same patient. These two strains were found to be homologous by pulsed-field gel electrophoresis, and both strains contained blaIMP-1, blaDHA-1, blaCTXM-14, blaTEM-1, and blaSHV-1. Based on the sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis, the lack of Ompk36 was observed in Mkp4437. Direct sequencing of the ompK36 gene demonstrated that a new insertional sequence in the open reading frame of the ompK36 gene was found in Mkp4437. Three clinical isolates (minimum inhibitory concentration [MIC] 2-4 mg/L to imipenem) were identified upon screening the strains of K. pneumoniae isolated in the University hospital with MICs of ≥ 1 mg/L to imipenem. Interestingly, these three isolates all lacked OmpK36. Conjugation of the plasmid harboring IMP-1 to these three OmpK36-deficient strains led to the isolation of high-level carbapenem-resistant transconjugants. In conclusion, the mechanisms of high-level carbapenem resistance in K. pneumoniae entail not only the production of IMP-1 β-lactamase but also the lack of OmpK36. It is vital to monitor for the presence of less carbapenem-sensitive K. pneumoniae strains, which lack OmpK36, because blaIMP-1 transmission to these strains may result in isolates with a high-level carbapenem-resistant phenotype.

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

    PubMed Central

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

    2016-01-01

    Purpose 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. Materials and Methods 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. Results 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. Conclusion 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. PMID:26847286

  8. Vancomycin and High Level Aminoglycoside Resistance in Enterococcus spp. in a Tertiary Health Care Centre: A Therapeutic Concern.

    PubMed

    Mittal, Seema; Singla, Pooja; Deep, Antariksha; Bala, Kiran; Sikka, Rama; Garg, Meenu; Chaudhary, Uma

    2016-01-01

    Aims. This study was aimed at knowing the prevalence of vancomycin and high level aminoglycoside resistance in enterococcal strains among clinical samples. Study Design. It was an investigational study. Place and Duration of Study. It was conducted on 100 Enterococcus isolates, in the Department of Microbiology, Pt. BDS PGIMS, Rohtak, over a period of six months from July to December 2014. Methodology. Clinical specimens including urine, pus, blood, semen, vaginal swab, and throat swab were processed and Enterococcus isolates were identified by standard protocols. Antibiotic sensitivity testing of enterococci was performed using Kirby-Bauer disc diffusion method. Results. High level gentamicin resistance (HLGR) was more common in urine samples (41.5%) followed by blood (36%) samples. High level streptomycin resistance (HLSR) was more common in pus samples (52.6%) followed by blood samples (36%). Resistance to vancomycin was maximum in blood isolates. Conclusion. Enterococci resistant to multiple antimicrobial agents have been recognized. Thus, it is crucial for laboratories to provide accurate antimicrobial resistance patterns for enterococci so that effective therapy and infection control measures can be initiated. PMID:27047693

  9. Vancomycin and High Level Aminoglycoside Resistance in Enterococcus spp. in a Tertiary Health Care Centre: A Therapeutic Concern

    PubMed Central

    Singla, Pooja; Deep, Antariksha; Bala, Kiran; Sikka, Rama; Garg, Meenu; Chaudhary, Uma

    2016-01-01

    Aims. This study was aimed at knowing the prevalence of vancomycin and high level aminoglycoside resistance in enterococcal strains among clinical samples. Study Design. It was an investigational study. Place and Duration of Study. It was conducted on 100 Enterococcus isolates, in the Department of Microbiology, Pt. BDS PGIMS, Rohtak, over a period of six months from July to December 2014. Methodology. Clinical specimens including urine, pus, blood, semen, vaginal swab, and throat swab were processed and Enterococcus isolates were identified by standard protocols. Antibiotic sensitivity testing of enterococci was performed using Kirby-Bauer disc diffusion method. Results. High level gentamicin resistance (HLGR) was more common in urine samples (41.5%) followed by blood (36%) samples. High level streptomycin resistance (HLSR) was more common in pus samples (52.6%) followed by blood samples (36%). Resistance to vancomycin was maximum in blood isolates. Conclusion. Enterococci resistant to multiple antimicrobial agents have been recognized. Thus, it is crucial for laboratories to provide accurate antimicrobial resistance patterns for enterococci so that effective therapy and infection control measures can be initiated. PMID:27047693

  10. Vancomycin and High Level Aminoglycoside Resistance in Enterococcus spp. in a Tertiary Health Care Centre: A Therapeutic Concern.

    PubMed

    Mittal, Seema; Singla, Pooja; Deep, Antariksha; Bala, Kiran; Sikka, Rama; Garg, Meenu; Chaudhary, Uma

    2016-01-01

    Aims. This study was aimed at knowing the prevalence of vancomycin and high level aminoglycoside resistance in enterococcal strains among clinical samples. Study Design. It was an investigational study. Place and Duration of Study. It was conducted on 100 Enterococcus isolates, in the Department of Microbiology, Pt. BDS PGIMS, Rohtak, over a period of six months from July to December 2014. Methodology. Clinical specimens including urine, pus, blood, semen, vaginal swab, and throat swab were processed and Enterococcus isolates were identified by standard protocols. Antibiotic sensitivity testing of enterococci was performed using Kirby-Bauer disc diffusion method. Results. High level gentamicin resistance (HLGR) was more common in urine samples (41.5%) followed by blood (36%) samples. High level streptomycin resistance (HLSR) was more common in pus samples (52.6%) followed by blood samples (36%). Resistance to vancomycin was maximum in blood isolates. Conclusion. Enterococci resistant to multiple antimicrobial agents have been recognized. Thus, it is crucial for laboratories to provide accurate antimicrobial resistance patterns for enterococci so that effective therapy and infection control measures can be initiated.

  11. A Novel Tryptophanyl-tRNA Synthetase Gene Confers High-Level Resistance to Indolmycin▿ †

    PubMed Central

    Vecchione, James J.; Sello, Jason K.

    2009-01-01

    Indolmycin, a potential antibacterial drug, competitively inhibits bacterial tryptophanyl-tRNA synthetases. An effort to identify indolmycin resistance genes led to the discovery of a gene encoding an indolmycin-resistant isoform of tryptophanyl-tRNA synthetase. Overexpression of this gene in an indolmycin-sensitive strain increased the indolmycin MIC 60-fold. Its transcription and distribution in various bacterial genera were assessed. The level of resistance conferred by this gene was compared to that of a known indolmycin resistance gene and to those of genes with resistance-conferring point mutations. PMID:19546369

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

    PubMed

    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.

  13. High level of resistance to aztreonam and ticarcillin in Pseudomonas aeruginosa isolated from soil of different crops in Brazil.

    PubMed

    Pitondo-Silva, André; Martins, Vinicius Vicente; Fernandes, Ana Flavia Tonelli; Stehling, Eliana Guedes

    2014-03-01

    Pseudomonas aeruginosa can be found in water, soil, plants and, human and animal fecal samples. It is an important nosocomial pathogenic agent characterized by an intrinsic resistance to multiple antimicrobial agents and the ability to develop high-level (acquired) multidrug resistance through some mechanisms, among them, by the acquisition of plasmids and integrons, which are mobile genetic elements. In this study, 40 isolates from Brazilian soil were analyzed for antibiotic resistance, presence of integrons and plasmidial profile. The results demonstrated that the vast majority of the isolates have shown resistance for aztreonam (92.5%, n=37) and ticarcillin (85%, n=34), four isolates presented plasmids and eight isolates possess the class 1 integron. These results demonstrated that environmental isolates of P. aeruginosa possess surprising antibiotic resistance profile to aztreonam and ticarcillin, two antimicrobial agents for clinical treatment of cystic fibrosis patients and other infections occurred by P. aeruginosa. PMID:24369293

  14. Neisseria gonorrhoeae strain with high-level resistance to spectinomycin due to a novel resistance mechanism (mutated ribosomal protein S5) verified in Norway.

    PubMed

    Unemo, Magnus; Golparian, Daniel; Skogen, Vegard; Olsen, Anne Olaug; Moi, Harald; Syversen, Gaute; Hjelmevoll, Stig Ove

    2013-02-01

    Gonorrhea may become untreatable, and new treatment options are essential. Verified resistance to spectinomycin is exceedingly rare. However, we describe a high-level spectinomycin-resistant (MIC, >1,024 μg/ml) Neisseria gonorrhoeae strain from Norway with a novel resistance mechanism. The resistance determinant was a deletion of codon 27 (valine) and a K28E alteration in the ribosomal protein 5S. The traditional spectinomycin resistance gene (16S rRNA) was wild type. Despite this exceedingly rare finding, spectinomycin available for treatment of ceftriaxone-resistant urogenital gonorrhea would be very valuable. PMID:23183436

  15. High-level Multi-Resistant and Virulent Escherichia coli in Abeokuta, Nigeria.

    PubMed

    Akinduti, Paul Akinniyi; Aboderin, Bukola W; Oloyede, Rasaq; Ogiogwa, Joseph I; Motayo, Babatunde O; Ejilude, Oluwaseun

    2016-01-01

    Multi-resistant Escherichia coli (E. coli) strains co-harboring virulence genes is a cause of high morbidity in Abeokuta, Nigeria. This study was designed to determine some virulent factors among enteropathogenic E. coli in Abeokuta, Nigeria. Approximately non-repetitive 102 isolates of E. coli were recovered from clinical samples from two health facilities in Abeokuta. Biotyping using API and antibiotic susceptibility was determined, and eae and flic genes were assayed by PCR. Antibiotic resistance relatedness was performed by DendroUPGMA. Results showed that 48.0% and 52.0 % were intestinal and extra-intestinal E. coli, ampicillin recorded 100% resistance, amoxycilli/clavulanic acid 64.7%, cotrimoxazole 57.8% and 56.8% resistance against cefotaxime, at MIC >16 ug/mL, 100%, 57.8%, and 50% have MIC50 to ampicillin, tetracycline, and ceftazidime, while 74.5% and 48.0% have MIC90 to ampicillin and ceftazidime. Significant rates of 4.9%, 7.8%, and 9.8% flic, eae, and flic/eae genes were found in intestinal isolates, while 2.9%, 2.0%, and 3.9% were found in extra-intestinal (P < 0.05). Two major clades of the resistant isolates reveal significant antibiotic relatedness among intestinal and extra-intestinal isolates, at 54% resistance similarities with very high multi-antibiotic resistance index of 1.0 (MARI). A high rate of undetected virulent E. coli pathotypes with high resistance could trigger unprecedented morbidity and mortality, mostly among children and the elderly.

  16. Molecular characterization and analysis of high-level multidrug-resistance of Shigella flexneri serotype 4s strains from China

    PubMed Central

    Yang, Chaojie; Li, Peng; Zhang, Xiujuan; Ma, Qiuxia; Cui, Xianyan; Li, Hao; Liu, Hongbo; Wang, Jian; Xie, Jing; Wu, Fuli; Sheng, Chunyu; Du, Xinying; Qi, Lihua; Su, Wenli; Jia, Leili; Xu, Xuebin; Zhao, Jiayong; Xia, Shengli; Zhou, Na; Ma, Hui; Qiu, Shaofu; Song, Hongbin

    2016-01-01

    To conduct the first comprehensive analysis of Shigella flexneri serotype 4s, a novel serotype found in 2010, we identified 24 serotype 4s isolates from 1973 shigellosis cases in China (2002–2014). The isolates were characterized by single nucleotide polymorphism (SNP) phylogenetic analysis, pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) to determine their genetic relatedness, and analysed further for their antimicrobial susceptibilities and antimicrobial resistance determinants. The PFGE and SNP phylogenetic analyses suggest that S. flexneri serotype 4s strains are derived from multiple serotypes, including two predominant serotypes in China: serotype X variant and serotype II. Three new sequence types were identified by MLST. All isolates were resistant to ticarcillin, ampicillin and tetracycline, with high-level resistance to third-generation cephalosporins. Notably, all the isolates were multidrug resistant (MDR), with the highest levels of resistance observed for eight antimicrobials classes. Most isolates contain various antimicrobial resistance determinants. In conclusion, we found that serotype 4s isolates have multiple evolutionary sources, diverse biochemical characteristics and genomes, and highly prevalent multidrug resistance and antimicrobial-resistant determinants. With few clinical treatment options, continuous monitoring and timely intervention against this emerging MDR serotype is essential. The possibility that serotype 4s will become the next predominant serotype exists. PMID:27374009

  17. Molecular characterization and analysis of high-level multidrug-resistance of Shigella flexneri serotype 4s strains from China.

    PubMed

    Yang, Chaojie; Li, Peng; Zhang, Xiujuan; Ma, Qiuxia; Cui, Xianyan; Li, Hao; Liu, Hongbo; Wang, Jian; Xie, Jing; Wu, Fuli; Sheng, Chunyu; Du, Xinying; Qi, Lihua; Su, Wenli; Jia, Leili; Xu, Xuebin; Zhao, Jiayong; Xia, Shengli; Zhou, Na; Ma, Hui; Qiu, Shaofu; Song, Hongbin

    2016-01-01

    To conduct the first comprehensive analysis of Shigella flexneri serotype 4s, a novel serotype found in 2010, we identified 24 serotype 4s isolates from 1973 shigellosis cases in China (2002-2014). The isolates were characterized by single nucleotide polymorphism (SNP) phylogenetic analysis, pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) to determine their genetic relatedness, and analysed further for their antimicrobial susceptibilities and antimicrobial resistance determinants. The PFGE and SNP phylogenetic analyses suggest that S. flexneri serotype 4s strains are derived from multiple serotypes, including two predominant serotypes in China: serotype X variant and serotype II. Three new sequence types were identified by MLST. All isolates were resistant to ticarcillin, ampicillin and tetracycline, with high-level resistance to third-generation cephalosporins. Notably, all the isolates were multidrug resistant (MDR), with the highest levels of resistance observed for eight antimicrobials classes. Most isolates contain various antimicrobial resistance determinants. In conclusion, we found that serotype 4s isolates have multiple evolutionary sources, diverse biochemical characteristics and genomes, and highly prevalent multidrug resistance and antimicrobial-resistant determinants. With few clinical treatment options, continuous monitoring and timely intervention against this emerging MDR serotype is essential. The possibility that serotype 4s will become the next predominant serotype exists. PMID:27374009

  18. Observations on high levels of fusidic acid resistant Staphylococcus aureus in Harrogate, North Yorkshire, UK.

    PubMed

    Ravenscroft, J C; Layton, A; Barnham, M

    2000-06-01

    A retrospective study was carried out to investigate possible reasons for a marked increase in fusidic acid-resistant Staphylococcus aureus (FusR S. aureus) identified by our routine hospital microbiology service. Information was obtained on a sample of 64 consecutive patients from whom resistant S. aureus had been cultured. The source of isolates was found to be diffuse within the hospital and community. The site of sample was most frequently chronic cutaneous infections (68%). All the S. aureus isolates were resistant to both fusidic acid and penicillin and many were resistant to multiple antibiotics. Topical fusidic acid had been used by 40% of patients in the preceding 6 months and none had received oral fusidic acid (sodium fusidate). Most (80%) had received an oral antibiotic in the preceding 2 years. Information from the Prescriptions Pricing Authority revealed that the total number of prescriptions for fusidic acid-containing preparations for the period September 1997 to August 1998 was markedly higher in Harrogate than in five other local areas where increases in (FusR) S. aureus have not been observed.

  19. Emergence of high level azithromycin-resistant Neisseria gonorrhoeae strain isolated in Argentina.

    PubMed

    Galarza, Patricia G; Alcalá, Belén; Salcedo, Celia; Canigia, Liliana Fernández; Buscemi, Luis; Pagano, Irene; Oviedo, Claudia; Vázquez, Julio A

    2009-12-01

    One Neisseria gonorrhoeae strains highly resistant to azithromycin AzHLR (MIC >2048 mg/L) was isolated in Argentina in 2001 and it has been characterized by N. gonorrhoeae multiantigen sequence typing (NG-MAST) as ST696, suggesting a different event to other isolates in Europe. Neither, mtrR mutations or presence of mef gene were detected.

  20. Abdominal Obesity and Insulin Resistance in People Exposed to Moderate-to-High Levels of Dioxin

    PubMed Central

    Chang, Jung-Wei; Chen, Hsiu-Ling; Su, Huey-Jen; Lee, Ching-Chang

    2016-01-01

    Obesity, a risk factor for developing metabolic complications, is a major public health problem. Abdominal obesity is strongly accompanied by a cluster of metabolic abnormalities characterized by insulin resistance. The link between persistent organic pollutants (POPs) and insulin resistance has been investigated in animal and epidemiological studies. We aimed to examine whether insulin resistance is greater in people with abdominal obesity (AO) and concomitant exposure to serum dioxins (PCDD/Fs). We conducted a cross-sectional descriptive study of 2876 participants living near a PCDD/Fs contaminated area. Seventeen 2,3,7,8-substituted PCDD/Fs congeners were measured, and then the associations between the main predictor variable, serum TEQDF-1998, abdominal obesity (AO), dependent variables, and insulin resistance were examined. Twelve of the 17 congeners, widely distributed among PCDDs, and PCDFs, had trends for associations with abdominal adiposity. In men, the highest quintiles of 1,2,3,7,8-PeCDF; 1,2,3,7,8-PeCDD; 2,3,7,8-TCDD; 2,3,7,8-TCDF; and 2,3,4,7,8-PeCDF had the top five adjusted odds ratios (AORs) + 95% confidence intervals (CIs):[4.2; 2.7–6.4], [3.6; 2.3–5.7], [3.2; 2.1–5.0], [3.0; 2.0–4.5], and [2.9; 1.9–4.7], respectively. In women, the highest quintiles of 1,2,3,4,7,8,9-HpCDF; 1,2,3,6,7,8-HxCDF; and 1,2,3,4,6,7,8-HpCDF had the top three AORs + 95% CIs:[3.0; 1.9–4.7], [2.0; 1.3–3.1], and [1.9; 1.3–2.9], respectively. After confounding factors had been adjusted for, men, but not women, with higher serum TEQDF-1998 levels or abdominal obesity had a significantly (Ptrend < 0.001) greater risk for abnormal insulin resistance. The groups with the highest joint serum TEQDF-1998 and abdominal obesity levels were associated with elevated insulin resistance at 5.0 times the odds of the groups with the lowest joint levels (AOR 5.23; 95% CI: 3.53–7.77). We hypothesize that serum TEQDF-1998 and abdominal obesity affect the association with

  1. High-Level Chromate Resistance in Arthrobacter sp. strain FB24 Requires Previously Uncharacterized Accessory Genes

    SciTech Connect

    Henne, Kristene L.; Nakatsu, Cindy N.; Thompson, Dorothea K.; Konopka, Allan

    2009-09-24

    The annotated genome sequence of Arthrobacter sp. strain FB24 revealed a chromate resistance determinant (CRD): a cluster of 8 genes located on a 10.6 kb fragment of a 96 kb plasmid. The CRD includes chrA, which encodes a putative chromate efflux protein, and three genes with amino acid similarities to the amino and carboxy termini of ChrB, a putative regulatory protein. There are also three novel genes that have not been previously associated with chromate resistance in other bacteria; they encode an oxidoreductase (most similar to malate:quinone oxidoreductase), a functionally unknown protein with a WD40 repeat domain and a lipoprotein. A chromate-sensitive mutant (strain D11) was generated by curing FB24 of its 96-kb plasmid. Elemental analysis indicated that chromate-exposed cells of strain D11 accumulated three times more chromium than strain FB24. Introduction of the CRD into strain D11 conferred chromate resistance comparable to wild-type levels, whereas deletion of specific regions of the CRD led to decreased resistance. Using real-time reverse transcriptase PCR, we show that expression of each gene within the CRD is specifically induced in response to chromate but not by lead, hydrogen peroxide or arsenate. Higher levels of chrA expression were achieved when the chrB orthologs and the WD40 repeat domain genes were present, suggesting their regulatory roles. Collectively, our findings indicate that chromate resistance in strain FB24 is primarily achieved by plasmid-mediated chromate efflux with the contribution of previously unrecognized accessory genes.

  2. High level multiple antibiotic resistance among fish surface associated bacterial populations in non-aquaculture freshwater environment.

    PubMed

    Ozaktas, Tugba; Taskin, Bilgin; Gozen, Ayse G

    2012-12-01

    Freshwater fish, Alburnus alburnus (bleak), were captured from Lake Mogan, situated in Ankara, during spring. The surface mucus of the fish was collected and associated bacteria were cultured and isolated. By sequencing PCR-amplified 16S RNA encoding genes, the isolates were identified as members of 12 different genera: Acinetobacter, Aeromonas, Bacillus, Brevundimonas, Gordonia, Kocuria, Microbacterium, Mycobacterium, Pseudomonas, Rhodococcus, and Staphylococcus, in addition to one strain that was unidentified. The mucus-dwelling bacterial isolates were tested for resistance against ampicillin, kanamycin, streptomycin and chloramphenicol. About 95% of the isolates were found to be resistant to ampicillin, 93% to chloramphenicol, and 88% to kanamycin and streptomycin. A Microbacterium oxydans and the unidentified environmental isolate were resistant to all four antibiotics tested at very high levels (>1600 μg/ml ampicillin and streptomycin; >1120 μg/ml kanamycin; >960 μg/ml chloramphenicol). Only a Kocuria sp. was sensitive to all four antibiotics at the lowest concentrations tested (3.10 μg/ml ampicillin and streptomycin; 2.15 μg/ml kanamycin; 1.85 μg/ml chloramphenicol). The rest of the isolates showed different resistance levels. Plasmid isolations were carried out to determine if the multiple antibiotic resistance could be attributed to the presence of plasmids. However, no plasmid was detected in any of the isolates. The resistance appeared to be mediated by chromosome-associated functions. This study indicated that multiple antibiotic resistance at moderate to high levels is common among the current phenotypes of the fish mucus-dwelling bacterial populations in this temperate, shallow lake which has not been subjected to any aquaculturing so far but under anthropogenic effect being in a recreational area. PMID:23039919

  3. Clinical isolate of a porinless Salmonella typhi resistant to high levels of chloramphenicol.

    PubMed Central

    Toro, C S; Lobos, S R; Calderón, I; Rodríguez, M; Mora, G C

    1990-01-01

    We studied a clinical isolate of Salmonella typhi (strain 1895) characterized by resistance to 200 micrograms of chloramphenicol per ml despite the absence of chloramphenicol-inactivating activity. The outer membrane protein profile analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated a deficiency of one of the major protein species which may serve as a porin for entry of chloramphenicol. When the strain was transformed with a plasmid encoding chloramphenicol acetyltransferase, chloramphenicol added to the culture was not inactivated, suggesting a drastic reduction of permeability towards the drug. Moreover, transformants bearing a plasmid coding for the Escherichia coli OmpF porin became considerably more susceptible to chloramphenicol (40 micrograms/ml). On the other hand, transformants carrying a plasmid encoding the Salmonella typhi ompC gene remained as resistant to the drug as the parental strain, even though they overexpressed OmpC. These findings indicate that the lack of OmpF plays a major role in the resistance to chloramphenicol in strain 1895. Images PMID:2285283

  4. High-Level Primary Clarithromycin Resistance of Helicobacter pylori in Algiers, Algeria: A Prospective Multicenter Molecular Study.

    PubMed

    Djennane-Hadibi, Fazia; Bachtarzi, Mohamed; Layaida, Karim; Ali Arous, Nassima; Nakmouche, Mhamed; Saadi, Berkane; Tazir, Mohamed; Ramdani-Bouguessa, Nadjia; Burucoa, Christophe

    2016-04-01

    Knowledge of local antibiotic resistance is crucial to adaptation for the choice of the optimal first-line treatment for Helicobacter pylori infection. Clarithromycin is a key component of the standard triple therapy largely used worldwide and, more particularly, in Algeria. Clarithromycin resistance is the main risk factor for treatment failure. The aim of this study was to evaluate, for the first time in Algeria, the prevalence of the primary resistance of H. pylori to clarithromycin. We conducted a prospective study (2008-2014) that included 195 Algerian patients referred for gastroduodenal endoscopy to two University Hospitals, one General Hospital, and several private gastroenterologists in Algiers (Algeria). One gastric biopsy was collected for the molecular detection of H. pylori and the mutations in 23S rRNA genes that confer resistance to clarithromycin with a quadruplex real-time PCR using Scorpion primers. The Scorpion PCR detected H. pylori DNA in 91 biopsies (47%). A mutation conferring resistance to clarithromycin was detected in 32 of the 91 positive patients (35%) and in 29 of the 88 positive patients never previously treated for an H. pylori infection (33%). The prevalence of primary resistance of H. pylori to clarithromycin was 33% in the Algerian population being studied. The high level of primary clarithromycin resistance in the H. pylori strains infecting the Algerian population that we report leads us to recommend the abandonment of the standard clarithromycin-based triple therapy as a first-line treatment in Algeria. PMID:26554340

  5. Studies of Corrosion Resistant Materials Being Considered for High-Level Nuclear Waste Containment in Yucca Mountain Relevant Environments

    SciTech Connect

    McCright, R.D.; Ilevbare, G.; Estill, J.; Rebak, R.

    2001-12-09

    Containment of spent nuclear fuel and vitrified forms of high level nuclear waste require use of materials that are highly corrosion resistant to all of the anticipated environmental scenarios that can occur in a geological repository. Ni-Cr-Mo Alloy 22 (UNS N60622) is proposed for the corrosion resistant outer barrier of a two-layer waste package container at the potential repository site at Yucca Mountain. A range of water compositions that may contact the outer barrier is under consideration, and a testing program is underway to characterize the forms of corrosion and to quantify the corrosion rates. Results from the testing support models for long term prediction of the performance of the container. Results obtained to date indicate a very low general corrosion rate for Alloy 22 and very high resistance to all forms of localized and environmentally assisted cracking in environments tested to date.

  6. High-level carbapenem resistance in a Citrobacter freundii clinical isolate is due to a combination of KPC-2 production and decreased porin expression.

    PubMed

    Zhang, Rong; Yang, Lijiang; Cai, Jia Chang; Zhou, Hong Wei; Chen, Gong-Xiang

    2008-03-01

    An imipenem-resistant isolate of Citrobacter freundii ZJ163 (MIC 256 microg ml(-1)) isolated from a Chinese hospital was investigated. The C. freundii ZJ163 isolate exhibited high-level resistance to carbapenems, penicillins, cephalosporins, cefoxitin, aztreonam, quinolones and aminoglycosides. Isoelectric focusing (IEF) demonstrated three beta-lactamases with pIs of 5.4 (TEM-1), 6.7 (KPC-2) and 7.9 (CTX-M-14). Two different transconjugants (types A and B) were obtained by conjugation studies. The type A transconjugant exhibited reduced susceptibility or resistance to penicillins, cephalosporins and aztreonam, but was susceptible to carbapenems, quinolones and aminoglycosides. The antimicrobial susceptibility patterns of the type B transconjugant were similar to that of type A, except for its significantly reduced carbapenem susceptibility (imipenem MIC 2 microg ml(-1)). IEF, specific PCRs and DNA sequence analysis indicated that the type A transconjugant produced CTX-M-14 beta-lactamase with a pI of 7.9, that the type B transconjugant produced KPC-2 beta-lactamase with a pI of 6.7 and that the beta-lactamase with a pI of 5.4 was TEM-1. PCR analysis and sequencing confirmed the presence of the ampC gene in the chromosomal DNA from C. freundii ZJ163, although no activity of AmpC beta-lactamase was detected by IEF. Urea/SDS-PAGE analysis of outer-membrane proteins revealed that the levels of the 41 and 38 kDa porins were decreased in C. freundii ZJ163. It was concluded that production of KPC-2 combined with decreased expression of porins contributes to high-level resistance to carbapenems in C. freundii ZJ163.

  7. K70Q Adds High-Level Tenofovir Resistance to “Q151M Complex” HIV Reverse Transcriptase through the Enhanced Discrimination Mechanism

    PubMed Central

    Hachiya, Atsuko; Kodama, Eiichi N.; Schuckmann, Matthew M.; Kirby, Karen A.; Michailidis, Eleftherios; Sakagami, Yasuko; Oka, Shinichi; Singh, Kamalendra; Sarafianos, Stefan G.

    2011-01-01

    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. PMID:21249155

  8. An Environmental Shiga Toxin-Producing Escherichia coli O145 Clonal Population Exhibits High-Level Phenotypic Variation That Includes Virulence Traits

    PubMed Central

    Quinones, Beatriz; He, Xiaohua; Zhong, Wayne; Louie, Jacqueline W.; Lee, Bertram G.; Yambao, Jaszemyn C.; Mandrell, Robert E.; Cooley, Michael B.

    2015-01-01

    Shiga toxin-producing Escherichia coli (STEC) serotype O145 is one of the major non-O157 serotypes associated with severe human disease. Here we examined the genetic diversity, population structure, virulence potential, and antimicrobial resistance profiles of environmental O145 strains recovered from a major produce production region in California. Multilocus sequence typing analyses revealed that sequence type 78 (ST-78), a common ST in clinical strains, was the predominant genotype among the environmental strains. Similarly, all California environmental strains belonged to H28, a common H serotype in clinical strains. Although most environmental strains carried an intact fliC gene, only one strain retained swimming motility. Diverse stx subtypes were identified, including stx1a, stx2a, stx2c, and stx2e. Although no correlation was detected between the stx genotype and Stx1 production, high Stx2 production was detected mainly in strains carrying stx2a only and was correlated positively with the cytotoxicity of Shiga toxin. All environmental strains were capable of producing enterohemolysin, whereas only 10 strains were positive for anaerobic hemolytic activity. Multidrug resistance appeared to be common, as nearly half of the tested O145 strains displayed resistance to at least two different classes of antibiotics. The core virulence determinants of enterohemorrhagic E. coli were conserved in the environmental STEC O145 strains; however, there was large variation in the expression of virulence traits among the strains that were highly related genotypically, implying a trend of clonal divergence. Several cattle isolates exhibited key virulence traits comparable to those of the STEC O145 outbreak strains, emphasizing the emergence of hypervirulent strains in agricultural environments. PMID:26637597

  9. An Environmental Shiga Toxin-Producing Escherichia coli O145 Clonal Population Exhibits High-Level Phenotypic Variation That Includes Virulence Traits.

    PubMed

    Carter, Michelle Qiu; Quinones, Beatriz; He, Xiaohua; Zhong, Wayne; Louie, Jacqueline W; Lee, Bertram G; Yambao, Jaszemyn C; Mandrell, Robert E; Cooley, Michael B

    2015-12-04

    Shiga toxin-producing Escherichia coli (STEC) serotype O145 is one of the major non-O157 serotypes associated with severe human disease. Here we examined the genetic diversity, population structure, virulence potential, and antimicrobial resistance profiles of environmental O145 strains recovered from a major produce production region in California. Multilocus sequence typing analyses revealed that sequence type 78 (ST-78), a common ST in clinical strains, was the predominant genotype among the environmental strains. Similarly, all California environmental strains belonged to H28, a common H serotype in clinical strains. Although most environmental strains carried an intact fliC gene, only one strain retained swimming motility. Diverse stx subtypes were identified, including stx1a, stx2a, stx2c, and stx2e. Although no correlation was detected between the stx genotype and Stx1 production, high Stx2 production was detected mainly in strains carrying stx2a only and was correlated positively with the cytotoxicity of Shiga toxin. All environmental strains were capable of producing enterohemolysin, whereas only 10 strains were positive for anaerobic hemolytic activity. Multidrug resistance appeared to be common, as nearly half of the tested O145 strains displayed resistance to at least two different classes of antibiotics. The core virulence determinants of enterohemorrhagic E. coli were conserved in the environmental STEC O145 strains; however, there was large variation in the expression of virulence traits among the strains that were highly related genotypically, implying a trend of clonal divergence. Several cattle isolates exhibited key virulence traits comparable to those of the STEC O145 outbreak strains, emphasizing the emergence of hypervirulent strains in agricultural environments.

  10. Frequency of biocide-resistant genes and susceptibility to chlorhexidine in high-level mupirocin-resistant, methicillin-resistant Staphylococcus aureus (MuH MRSA).

    PubMed

    Liu, Qingzhong; Zhao, Huanqiang; Han, Lizhong; Shu, Wen; Wu, Qiong; Ni, Yuxing

    2015-08-01

    The aim of this study was to determine the prevalence of biocide-resistant determinants and the susceptibility to chlorhexidine in high-level mupirocin-resistant, methicillin-resistant Staphylococcus aureus (MuH MRSA). Fifty-three MuH MRSA isolates were analyzed for plasmid-borne genes (qacA/B, smr, qacG, qacH, and qacJ) by polymerase chain reaction (PCR); for chromosome-mediated genes (norA, norB, norC, mepA, mdeA, sepA, and sdrM) by PCR and quantitative reverse transcription-PCR (qRT-PCR); and for susceptibility to chlorhexidine by MIC and minimum bactericidal concentration (MBC). Furthermore, disinfectant efficacy was tested in the presence of 3.0% bovine serum albumin (BSA) in MBC detection. The plasmid-borne genes qacA/B (83.0%) and smr (77.4%) and overexpressions of chromosome-mediated genes norA (49.0%) and norB (28.8%) were predominantly found in isolates studied, and 90.6% of the isolates revealed tolerance to chlorhexidine. In the presence of BSA, the average MBC of chlorhexidine for these isolates rose to 256 μg/mL. Altogether, our results suggest that surveillance of sensitivity to biocides among MuH MRSA isolates is essential for hospital infection control.

  11. A three amino acid deletion in the transmembrane domain of the nicotinic acetylcholine receptor α6 subunit confers high-level resistance to spinosad in Plutella xylostella

    PubMed Central

    Wang, Jing; Wang, Xingliang; Lansdell, Stuart J.; Zhang, Jianheng; Millar, Neil S.; Wu, Yidong

    2016-01-01

    Spinosad is a macrocyclic lactone insecticide that acts primarily at the nicotinic acetylcholine receptors (nAChRs) of target insects. Here we describe evidence that high levels of resistance to spinosad in the diamondback moth (Plutella xylostella) are associated with a three amino acid (3-aa) deletion in the fourth transmembrane domain (TM4) of the nAChR α6 subunit (Pxα6). Following laboratory selection with spinosad, the SZ-SpinR strain of P. xylostella exhibited 940-fold resistance to spinosad. In addition, the selected insect population had 1060-fold cross-resistance to spinetoram but, in contrast, no cross-resistance to abamectin was observed. Genetic analysis indicates that spinosad resistance in SZ-SpinR is inherited as a recessive and autosomal trait, and that the 3-aa deletion (IIA) in TM4 of Pxα6 is tightly linked to spinosad resistance. Because of well-established difficulties in functional expression of cloned insect nAChRs, the analogous resistance-associated deletion mutation was introduced into a prototype nAChR (the cloned human α7 subunit). Two-electrode voltage-clamp recording with wild-type and mutated nAChRs expressed in Xenopus laevis oocytes indicated that the mutation causes a complete loss of agonist activation. In addition, radioligand binding studies indicated that the 3-aa deletion resulted in significantly lower-affinity binding of the extracellular neurotransmitter-binding site. These findings are consistent with the 3-amino acid (IIA) deletion within the transmembrane domain of Pxα6 being responsible for target-site resistance to spinosad in the SZ-SpinR strain of P. xylostella. PMID:26855198

  12. Arabidopsis Mutant bik1 Exhibits Strong Resistance to Plasmodiophora brassicae

    PubMed Central

    Chen, Tao; Bi, Kai; He, Zhangchao; Gao, Zhixiao; Zhao, Ying; Fu, Yanping; Cheng, Jiasen; Xie, Jiatao; Jiang, Daohong

    2016-01-01

    Botrytis-induced kinase1 (BIK1), a receptor-like cytoplasmic kinase, plays an important role in resistance against pathogens and insects in Arabidopsis thaliana. However, it remains unknown whether BIK1 functions against Plasmodiophora brassicae, an obligate biotrophic protist that attacks cruciferous plants and induces gall formation on roots. Here, we investigated the potential roles of receptors FLS2, BAK1, and BIK1 in the infection of P. brassicae cruciferous plants. Wild-type plants, fls2, and bak1 mutants showed typical symptom on roots, and the galls were filled with large quantities of resting spores, while bik1 mutant plants exhibited strong resistance to P. brassicae. Compared with that of the wild-type plants, the root hair and cortical infection rate of bik1 mutant were significantly reduced by about 40–50%. A considerable portion of bik1 roots failed to form typical galls. Even if some small galls were formed, they were filled with multinucleate secondary plasmodia. The bik1 plants accumulated less reactive oxygen species (ROS) at infected roots than other mutants and wild-type plants. Exogenous salicylic acid (SA) treatment alleviated the clubroot symptoms in wild-type plants, and the expression of the SA signaling marker gene PR1 was significantly increased in bik1. Both sid2 (salicylic acid induction-deficient 2) and npr1-1 [non-expresser of PR genes that regulate systemic acquired resistance (SAR)] mutants showed increased susceptibility to P. brassicae compared with wild-type plants. These results suggest that the resistance of bik1 to P. brassicae is possibly mediated by SA inducible mechanisms. PMID:27679580

  13. Arabidopsis Mutant bik1 Exhibits Strong Resistance to Plasmodiophora brassicae

    PubMed Central

    Chen, Tao; Bi, Kai; He, Zhangchao; Gao, Zhixiao; Zhao, Ying; Fu, Yanping; Cheng, Jiasen; Xie, Jiatao; Jiang, Daohong

    2016-01-01

    Botrytis-induced kinase1 (BIK1), a receptor-like cytoplasmic kinase, plays an important role in resistance against pathogens and insects in Arabidopsis thaliana. However, it remains unknown whether BIK1 functions against Plasmodiophora brassicae, an obligate biotrophic protist that attacks cruciferous plants and induces gall formation on roots. Here, we investigated the potential roles of receptors FLS2, BAK1, and BIK1 in the infection of P. brassicae cruciferous plants. Wild-type plants, fls2, and bak1 mutants showed typical symptom on roots, and the galls were filled with large quantities of resting spores, while bik1 mutant plants exhibited strong resistance to P. brassicae. Compared with that of the wild-type plants, the root hair and cortical infection rate of bik1 mutant were significantly reduced by about 40–50%. A considerable portion of bik1 roots failed to form typical galls. Even if some small galls were formed, they were filled with multinucleate secondary plasmodia. The bik1 plants accumulated less reactive oxygen species (ROS) at infected roots than other mutants and wild-type plants. Exogenous salicylic acid (SA) treatment alleviated the clubroot symptoms in wild-type plants, and the expression of the SA signaling marker gene PR1 was significantly increased in bik1. Both sid2 (salicylic acid induction-deficient 2) and npr1-1 [non-expresser of PR genes that regulate systemic acquired resistance (SAR)] mutants showed increased susceptibility to P. brassicae compared with wild-type plants. These results suggest that the resistance of bik1 to P. brassicae is possibly mediated by SA inducible mechanisms.

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

    PubMed

    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. PMID:16391058

  15. High levels of multiple metal resistance and its correlation to antibiotic resistance in environmental isolates of Acinetobacter.

    PubMed

    Dhakephalkar, P K; Chopade, B A

    1994-01-01

    Forty strains of Acinetobacter were isolated from different environmental sources. All the strains were classified into four genospecies, i.e., A. baumannii (33 isolates), A. calcoaceticus (three isolates), A. junii (three isolates) and A. genospecies3 (one isolate). Susceptibility of these 40 strains to salts of 20 heavy metals and 18 antibiotics was tested by the agar dilution method. All environmental isolates of Acinetobacter were resistant to multiple metal ions (minimum 13 metal ions) while all but one of the strains were resistant to multiple antibiotics (minimum four antibiotics). The maximum number of strains were found to be sensitive to mercury (60% strains) while all strains were resistant to copper, lead, boron and tungsten even at 10 mM concentration. Salts of these four metal ions may be added to the growth medium to facilitate selective isolation of Acinetobacter. Rifampicin and nalidixic acid were the most toxic antibiotics, inhibiting 94.5 and 89.5% of the acinetobacters, respectively. A. genospecies3 was found to be the most resistant species, tolerating high concentrations of all the 20 metal ions and also to a greater number of antibiotics than any other species of Acinetobacter tested. An inhibitory concentration (10 mM) of Ni(2+) and Zn(2+) was observed to inhibit the growth of all of the clinical isolates but allowed the growth of the environmental isolates, facilitating the differentiation between pathogenic and non-pathogenic acinetobacters. PMID:8118175

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

    PubMed Central

    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

  17. [Group D streptococci and enterococci: identification, sensitivity to antibiotics and a study of the high level resistance to aminosides (Charles Nicolle Hospital in Tunis)].

    PubMed

    Kechrid, A; Ben Redjeb, S; Gargouri, J; Fendri, C; Ben Hassen, E; Boujnah, A

    1991-01-01

    197 strains of enterococcus and group D Streptococcus were isolated from human material at Charles Nicolle Hospital (Tunis) and identified by biochemical tests: 174, Enterococcus faecalis, 6 Enterococcus faecium, 2 Enterococcus durans and 15 Streptococcus bovis. The sensitivity to antibiotics was studied: all Enterococcus faecium were resistant at least to one antibiotic, 15% of Enterococcus faecalis were sensitive for all antibiotics tested the other species were frequently sensitive. High level resistance to aminoglycosides were frequent in Enterococcus faecalis 40%: among these strains high level resistance to gentamicin accounts for 12% and 18 frequently associated with resistance to kanamycin and streptomycin, this situation present therapeutic problems in case of severe infection.

  18. Transgenic Wheat Expressing a Barley UDP-Glucosyltransferase Detoxifies Deoxynivalenol and Provides High Levels of Resistance to Fusarium graminearum.

    PubMed

    Li, Xin; Shin, Sanghyun; Heinen, Shane; Dill-Macky, Ruth; Berthiller, Franz; Nersesian, Natalya; Clemente, Thomas; McCormick, Susan; Muehlbauer, Gary J

    2015-11-01

    Fusarium head blight (FHB), mainly caused by Fusarium graminearum, is a devastating disease of wheat that results in economic losses worldwide. During infection, F. graminearum produces trichothecene mycotoxins, including deoxynivalenol (DON), that increase fungal virulence and reduce grain quality. Transgenic wheat expressing a barley UDP-glucosyltransferase (HvUGT13248) were developed and evaluated for FHB resistance, DON accumulation, and the ability to metabolize DON to the less toxic DON-3-O-glucoside (D3G). Point-inoculation tests in the greenhouse showed that transgenic wheat carrying HvUGT13248 exhibited significantly higher resistance to disease spread in the spike (type II resistance) compared with nontransformed controls. Two transgenic events displayed complete suppression of disease spread in the spikes. Expression of HvUGT13248 in transgenic wheat rapidly and efficiently conjugated DON to D3G, suggesting that the enzymatic rate of DON detoxification translates to type II resistance. Under field conditions, FHB severity was variable; nonetheless, transgenic events showed significantly less-severe disease phenotypes compared with the nontransformed controls. In addition, a seedling assay demonstrated that the transformed plants had a higher tolerance to DON-inhibited root growth than nontransformed plants. These results demonstrate the utility of detoxifying DON as a FHB control strategy in wheat. PMID:26214711

  19. Characterisation of clinical meticillin-resistant Staphylococcus epidermidis demonstrating high levels of linezolid resistance (>256 μg/ml) resulting from transmissible and mutational mechanisms.

    PubMed

    Gabriel, Emma M; Fitzgibbon, Siobhan; Clair, James; Coffey, Aidan; O'Mahony, Jim M

    2015-07-01

    Staphylococcus epidermidis (S. epidermidis), one of the leading etiological agents of nosocomial infections poses a significant economic burden globally. Introduced in 2000, linezolid (LZD) has become an important antibiotic, used in nearly seventy countries worldwide to treat infections caused by Gram-positive pathogens such as meticillin-resistant Staphylococcus and Streptococcus species along with vancomycin-resistant enterococci. Resistance to LZD in clinical settings remains rare. Here, we report the emergence of meticillin resistant S. epidermidis (MRSE) clinical isolates from two voluntary general acute hospitals exhibiting higher than typically reported levels of LZD resistance (MIC>256 μg/ml). The MRSE ST-2 clone isolated from eight patients (2010-2011) not only possessed resistance-conferring mutations such as G2576T in domain V of 23S rRNA gene (as determined by HRM-PCR analysis) and R172C substitution in the ribosomal protein L3, but also carried the cfr gene (the only known transmissible mechanism of LZD resistance). All isolates possessed several key biofilm-associated genes (such as icaA, icaD, aap and atlE) and resistance to multiple clinically significant antibiotics was recorded. This study reports the earliest incidence (2010) of clinical MRSE in the Republic of Ireland demonstrating multiple LZD resistance mechanisms both mutational and potentially transmissible, and characterises this emerging resistance from a molecular perspective.

  20. Shot Noise in Semiconductor Heterostructure Systems Exhibiting Negative Differential Resistance

    NASA Astrophysics Data System (ADS)

    Song, W.; Kuznetsov, V. V.; Mendez, E. E.

    2002-03-01

    It has been observed [1,2] before that the shot noise of the current, I, in a resonant tunneling (RT) diode is enhanced over its classical value of 2eI in the region of negative differential resistance (NDR). Here we address the question of whether that enhancement is inherent to RT mechanism or general to any system that exhibits NDR. We have measured shot noise in a heterostructure consisting of two identical 4.2 nm /2.3 nm GaAs/AlGaAs superlattices (S) separated by a 10 nm AlGaAs barrier (B). When a voltage is applied between the two superlattices, electrons tunnel through the barrier from the emitter's miniband to the collector's. The current increases linearly with voltage until the two minibands are completely misaligned in energy, at which point the current drops and a sharp NDR develops. The shot noise measured at T=4K in this S-B-S structure was exactly 2eI through the entire voltage range, including NDR region. In contrast, similar measurement done in RT devices showed a shot noise at least three times its classical value. These results prove that enhancement of measured shot noise is not general to devices with NDR or related to electrical coupling with the external circuit, but it is a consequence of the physical mechanism underlying resonant tunneling. [1] G. Iannaccone et al., Phys. Rev. Lett. 80, 1054 (1998) [2] V. V. Kuznetsov et al., Phys. Rev. B 58, R10159 (1998)

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

    PubMed Central

    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

  2. BRCA2-deficient sarcomatoid mammary tumors exhibit multidrug resistance.

    PubMed

    Jaspers, Janneke E; Sol, Wendy; Kersbergen, Ariena; Schlicker, Andreas; Guyader, Charlotte; Xu, Guotai; Wessels, Lodewyk; Borst, Piet; Jonkers, Jos; Rottenberg, Sven

    2015-02-15

    Pan- or multidrug resistance is a central problem in clinical oncology. Here, we use a genetically engineered mouse model of BRCA2-associated hereditary breast cancer to study drug resistance to several types of chemotherapy and PARP inhibition. We found that multidrug resistance was strongly associated with an EMT-like sarcomatoid phenotype and high expression of the Abcb1b gene, which encodes the drug efflux transporter P-glycoprotein. Inhibition of P-glycoprotein could partly resensitize sarcomatoid tumors to the PARP inhibitor olaparib, docetaxel, and doxorubicin. We propose that multidrug resistance is a multifactorial process and that mouse models are useful to unravel this.

  3. An environmental shiga toxin-producing Escherichia coli O145 clonal population exhibits high-level phenotypic variation that includes virulence traits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Shiga toxin-producing Escherichia coli (STEC) serotype O145 is one of the major non-O157 serotypes associated with severe human disease. Here we examined the genetic diversity, population structure, virulence potential, and antibiotic resistance profile of environmental O145 strains isolated from a ...

  4. Corrosion resistant iron aluminides exhibiting improved mechanical properties and corrosion resistance

    DOEpatents

    Liu, Chain T.; McKamey, Claudette G.; Tortorelli, Peter F.; David, Stan A.

    1994-01-01

    The specification discloses a corrosion-resistant intermetallic alloy comprising, in atomic percent, an FeAl iron aluminide containing from about 30 to about 40% aluminum alloyed with from about 0.01 to 0.4% zirconium and from 0.01 to about 0.8% boron. The alloy exhibits considerably improved room temperature ductility for enhanced usefulness in structural applications. The high temperature strength and fabricability is improved by alloying with molybdenum, carbon, chromium and vanadium.

  5. Corrosion resistant iron aluminides exhibiting improved mechanical properties and corrosion resistance

    DOEpatents

    Liu, C.T.; McKamey, C.G.; Tortorelli, P.F.; David, S.A.

    1994-06-14

    The specification discloses a corrosion-resistant intermetallic alloy comprising, in atomic percent, an FeAl iron aluminide containing from about 30 to about 40% aluminum alloyed with from about 0.01 to 0.4% zirconium and from 0.01 to about 0.8% boron. The alloy exhibits considerably improved room temperature ductility for enhanced usefulness in structural applications. The high temperature strength and fabricability is improved by alloying with molybdenum, carbon, chromium and vanadium. 9 figs.

  6. Evolution of high-level ethambutol-resistant tuberculosis through interacting mutations in decaprenylphosphoryl-β-D-arabinose biosynthetic and utilization pathway genes.

    PubMed

    Safi, Hassan; Lingaraju, Subramanya; Amin, Anita; Kim, Soyeon; Jones, Marcus; Holmes, Michael; McNeil, Michael; Peterson, Scott N; Chatterjee, Delphi; Fleischmann, Robert; Alland, David

    2013-10-01

    To study the evolution of drug resistance, we genetically and biochemically characterized Mycobacterium tuberculosis strains selected in vitro for ethambutol resistance. Mutations in decaprenylphosphoryl-β-D-arabinose (DPA) biosynthetic and utilization pathway genes Rv3806c, Rv3792, embB and embC accumulated to produce a wide range of ethambutol minimal inhibitory concentrations (MICs) that depended on mutation type and number. Rv3806c mutations increased DPA synthesis, causing MICs to double from 2 to 4 μg/ml in a wild-type background and to increase from 16 to 32 μg/ml in an embB codon 306 mutant background. Synonymous mutations in Rv3792 increased the expression of downstream embC, an ethambutol target, resulting in MICs of 8 μg/ml. Multistep selection was required for high-level resistance. Mutations in embC or very high embC expression were observed at the highest resistance level. In clinical isolates, Rv3806c mutations were associated with high-level resistance and had multiplicative effects with embB mutations on MICs. Ethambutol resistance is acquired through the acquisition of mutations that interact in complex ways to produce a range of MICs, from those falling below breakpoint values to ones representing high-level resistance.

  7. High level production of β-galactosidase exhibiting excellent milk-lactose degradation ability from Aspergillus oryzae by codon and fermentation optimization.

    PubMed

    Zhao, Qianqian; Liu, Fei; Hou, Zhongwen; Yuan, Chao; Zhu, Xiqiang

    2014-03-01

    A β-galactosidase gene from Aspergillus oryzae was engineered utilizing codon usage optimization to be constitutively and highly expressed in the Pichia pastoris SMD1168H strain in a high-cell-density fermentation. After fermentation for 96 h in a 50-L fermentor using glucose and glycerol as combined carbon sources, the recombinant enzyme in the culture supernatant had an activity of 4,239.07 U mL(-1) with o-nitrophenyl-β-D-galactopyranoside as the substrate, and produced a total of extracellular protein content of 7.267 g L(-1) in which the target protein (6.24 g L(-1)) occupied approximately 86 %. The recombinant β-galactosidase exhibited an excellent lactose hydrolysis ability. With 1,000 U of the enzyme in 100 mL milk, 92.44 % lactose was degraded within 24 h at 60 °C, and the enzyme could also accomplish the hydrolysis at low temperatures of 37, 25, and 10 °C. Thus, this engineered strain had significantly higher fermentation level of A. oryzae lactase than that before optimization and the β-galactosidase may have a good application potential in whey and milk industries.

  8. The rph2 gene is responsible for high level resistance to phosphine in independent field strains of Rhyzopertha dominica.

    PubMed

    Mau, Yosep S; Collins, Patrick J; Daglish, Gregory J; Nayak, Manoj K; Ebert, Paul R

    2012-01-01

    The lesser grain borer Rhyzopertha dominica (F.) is one of the most destructive insect pests of stored grain. This pest has been controlled successfully by fumigation with phosphine for the last several decades, though strong resistance to phosphine in many countries has raised concern about the long term usefulness of this control method. Previous genetic analysis of strongly resistant (SR) R. dominica from three widely geographically dispersed regions of Australia, Queensland (SR(QLD)), New South Wales (SR(NSW)) and South Australia (SR(SA)), revealed a resistance allele in the rph1 gene in all three strains. The present study confirms that the rph1 gene contributes to resistance in a fourth strongly resistant strain, SR2(QLD), also from Queensland. The previously described rph2 gene, which interacts synergistically with rph1 gene, confers strong resistance on SR(QLD) and SR(NSW). We now provide strong circumstantial evidence that weak alleles of rph2, together with rph1, contribute to the strong resistance phenotypes of SR(SA) and SR2(QLD). To test the notion that rph1 and rph2 are solely responsible for the strong resistance phenotype of all resistant R. dominica, we created a strain derived by hybridising the four strongly resistant lines. Following repeated selection for survival at extreme rates of phosphine exposure, we found only slightly enhanced resistance. This suggests that a single sequence of genetic changes was responsible for the development of resistance in these insects.

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

    PubMed

    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

  10. Regenerated hair cells exhibit a transient resistance to aminoglycoside toxicity.

    PubMed

    Hashino, E; Salvi, R J

    1996-05-13

    Recent studies have demonstrated that sensory hair cells in the avian inner ear are reproduced by cell proliferation in response to the death of the original hair cell population. The regenerated hair cells appear to construct functional synaptic contacts, thereby transmitting acoustic signals to the peripheral nervous system. One of the most extraordinary, but overlooked characteristics of these regenerated hair cells, is their ability to survive in a highly ototoxic environment. Here, we report that hair cells regenerated after kanamycin induced hair cell loss can survive for a substantially longer time period than their predecessors during prolonged exposure to aminoglycoside antibiotics. The prolonged survival, however, belongs solely to the immature status of regenerated hair cells. Once the regenerated hair cells reach morphological maturation, they become vulnerable to aminoglycoside toxicity. Immunohistochemical evaluation of kanamycin suggested that kanamycin may be taken up into hair cells via a receptor-mediated endocytosis at their apical surfaces. By contrast, kanamycin was rarely incorporated into the cytoplasm of the regenerated hair cells. These results suggest that the process of a receptor-mediated transmembrane transport at the apical surface of hair cells is developmentally regulated, and that the lack of some of the assembly involved in the transmembrane transport could be responsible for the inhibition of aminoglycoside uptake, leading immature hair cells to be aminoglycoside resistant. PMID:8782910

  11. High-level cefixime- and ceftriaxone-resistant Neisseria gonorrhoeae in France: novel penA mosaic allele in a successful international clone causes treatment failure.

    PubMed

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

    2012-03-01

    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.

  12. High-level cefixime- and ceftriaxone-resistant Neisseria gonorrhoeae in France: novel penA mosaic allele in a successful international clone causes treatment failure.

    PubMed

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

    2012-03-01

    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

  13. Evolution of a double amino acid substitution in the 5-enolpyruvylshikimate-3-phosphate synthase in Eleusine indica conferring high-level glyphosate resistance.

    PubMed

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

    2015-04-01

    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

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

    PubMed Central

    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

  15. Evolution of a double amino acid substitution in the 5-enolpyruvylshikimate-3-phosphate synthase in Eleusine indica conferring high-level glyphosate resistance.

    PubMed

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

    2015-04-01

    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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  17. Evaluations of melon germplasm reported to exhibit host plant resistance to sweetpotato whitefly

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sweetpotato whitefly (MEAM1 cryptic species of Bemisia tabaci; SPWF) displaced B. tabaci biotype A in 1991 in the lower desert area of southern California and the adjoining areas of Arizona and western Mexico. The search for high-level host plant resistance to this devastating insect has been ongoin...

  18. Identification of amino acids conferring high-level resistance to expanded-spectrum cephalosporins in the penA gene from Neisseria gonorrhoeae strain H041.

    PubMed

    Tomberg, Joshua; Unemo, Magnus; Ohnishi, Makoto; Davies, Christopher; Nicholas, Robert A

    2013-07-01

    The recent identification of a high-level-ceftriaxone-resistant (MIC = 2 to 4 μg/ml) isolate of Neisseria gonorrhoeae from Japan (H041) portends the loss of ceftriaxone as an effective treatment for gonococcal infections. This is of grave concern because ceftriaxone is the last remaining option for first-line empirical antimicrobial monotherapy. The penA gene from H041 (penA41) is a mosaic penA allele similar to mosaic alleles conferring intermediate-level cephalosporin resistance (Ceph(i)) worldwide but has 13 additional mutations compared to the mosaic penA gene from the previously studied Ceph(i) strain 35/02 (penA35). When transformed into the wild-type strain FA19, the penA41 allele confers 300- and 570-fold increases in the MICs for ceftriaxone and cefixime, respectively. In order to understand the mechanisms involved in high-level ceftriaxone resistance and to improve surveillance and epidemiology during the potential emergence of ceftriaxone resistance, we sought to identify the minimum number of amino acid alterations above those in penA35 that confer high-level resistance to ceftriaxone. Using restriction fragment exchange and site-directed mutagenesis, we identified three mutations, A311V, T316P, and T483S, that, when incorporated into the mosaic penA35 allele, confer essentially all of the increased resistance of penA41. A311V and T316P are close to the active-site nucleophile Ser310 that forms the acyl-enzyme complex, while Thr483 is predicted to interact with the carboxylate of the β-lactam antibiotic. These three mutations have thus far been described only for penA41, but dissemination of these mutations in other mosaic alleles would spell the end of ceftriaxone as an effective treatment for gonococcal infections.

  19. Rapid assay of A2058T-mutated 23S rRNA allelic profiles associated with high-level macrolide resistance in Moraxella catarrhalis.

    PubMed

    Saito, Ryoichi; Kasai, Ayako; Ogihara, Shinji; Yamada, Kageto; Tao, Kazuyuki

    2015-09-01

    We report on a restriction fragment-length polymorphism (HpyCH4III) assay for profile analysis of 23S rRNA gene A2058T-mutated alleles associated with high-level macrolide resistance in Moraxella catarrhalis. Our assay results were supported by DNA sequencing analysis, allowed for simultaneous testing of many strains, and produced results from pure-cultured colonies within 4 h.

  20. High-level carbapenem-resistant OXA-48-producing Klebsiella pneumoniae with a novel OmpK36 variant and low-level, carbapenem-resistant, non-porin-deficient, OXA-181-producing Escherichia coli from Thailand.

    PubMed

    Lunha, Kamonwan; Chanawong, Aroonwadee; Lulitanond, Aroonlug; Wilailuckana, Chotechana; Charoensri, Nicha; Wonglakorn, Lumyai; Saenjamla, Pimjai; Chaimanee, Prajuab; Angkititrakul, Sunpetch; Chetchotisakd, Ploenchan

    2016-06-01

    Five blaOXA-48-like-carrying Enterobacteriaceae isolates collected from two Thai patients in December 2012 were characterized. Three Klebsiella pneumoniae isolates giving two different pulsed-field gel electrophoresis patterns and sequence types (ST11 and ST37) from patient 1 harbored blaOXA-48 locating on Tn1999.2, whereas two Escherichia coli isolates with the same pulsotype and ST5 from Patient 2 carried ISEcp1-associated blaOXA-181. One K. pneumoniae strain had blaSHV-12, blaDHA-1, qnrB, and qnrS, while another strain harbored blaCTX-M-15, qnrS and aac(6')-Ib-cr. The E. coli strain contained blaCTX-M-15, blaCMY-2, qnrS, and aac(6')-Ib-cr. Interestingly, the OXA-48 producers with a novel OmpK36 variant by a substitution of Gly to Asp in the L3 loop-borne PEFXG motif exhibited high-level resistance to ertapenem, imipenem, and meropenem. In contrast, the OXA-181 producer with non-porin-deficient background showed low-level resistance to ertapenem only. Both patients died because of either septic shock or pneumonia. This study showed the impact of OXA-48-like carbapenemases in porin-defective clinical isolate background, which may lead to serious therapeutic problems in the near future. PMID:27041106

  1. High-level carbapenem-resistant OXA-48-producing Klebsiella pneumoniae with a novel OmpK36 variant and low-level, carbapenem-resistant, non-porin-deficient, OXA-181-producing Escherichia coli from Thailand.

    PubMed

    Lunha, Kamonwan; Chanawong, Aroonwadee; Lulitanond, Aroonlug; Wilailuckana, Chotechana; Charoensri, Nicha; Wonglakorn, Lumyai; Saenjamla, Pimjai; Chaimanee, Prajuab; Angkititrakul, Sunpetch; Chetchotisakd, Ploenchan

    2016-06-01

    Five blaOXA-48-like-carrying Enterobacteriaceae isolates collected from two Thai patients in December 2012 were characterized. Three Klebsiella pneumoniae isolates giving two different pulsed-field gel electrophoresis patterns and sequence types (ST11 and ST37) from patient 1 harbored blaOXA-48 locating on Tn1999.2, whereas two Escherichia coli isolates with the same pulsotype and ST5 from Patient 2 carried ISEcp1-associated blaOXA-181. One K. pneumoniae strain had blaSHV-12, blaDHA-1, qnrB, and qnrS, while another strain harbored blaCTX-M-15, qnrS and aac(6')-Ib-cr. The E. coli strain contained blaCTX-M-15, blaCMY-2, qnrS, and aac(6')-Ib-cr. Interestingly, the OXA-48 producers with a novel OmpK36 variant by a substitution of Gly to Asp in the L3 loop-borne PEFXG motif exhibited high-level resistance to ertapenem, imipenem, and meropenem. In contrast, the OXA-181 producer with non-porin-deficient background showed low-level resistance to ertapenem only. Both patients died because of either septic shock or pneumonia. This study showed the impact of OXA-48-like carbapenemases in porin-defective clinical isolate background, which may lead to serious therapeutic problems in the near future.

  2. Mature-stem expression of a silencing-resistant sucrose isomerase gene drives isomaltulose accumulation to high levels in sugarcane.

    PubMed

    Mudge, Stephen R; Basnayake, Shiromi W V; Moyle, Richard L; Osabe, Kenji; Graham, Michael W; Morgan, Terence E; Birch, Robert G

    2013-05-01

    Isomaltulose (IM) is a natural isomer of sucrose. It is widely approved as a food with properties including slower digestion, lower glycaemic index and low cariogenicity, which can benefit consumers. Availability is currently limited by the cost of fermentative conversion from sucrose. Transgenic sugarcane plants with developmentally-controlled expression of a silencing-resistant gene encoding a vacuole-targeted IM synthase were tested under field conditions typical of commercial sugarcane cultivation. High yields of IM were obtained, up to 483 mm or 81% of total sugars in whole-cane juice from plants aged 13 months. Using promoters from sugarcane to drive expression preferentially in the sugarcane stem, IM levels were consistent between stalks and stools within a transgenic line and across consecutive vegetative field generations of tested high-isomer lines. Germination and early growth of plants from setts were unaffected by IM accumulation, up to the tested level around 500 mm in flanking stem internodes. These are the highest yields ever achieved of value-added materials through plant metabolic engineering. The sugarcane stem promoters are promising for strategies to achieve even higher IM levels and for other applications in sugarcane molecular improvement. Silencing-resistant transgenes are critical to deliver the potential of these promoters in practical sugarcane improvement. At the IM levels now achieved in field-grown sugarcane, direct production of IM in plants is feasible at a cost approaching that of sucrose, which should make the benefits of IM affordable on a much wider scale. PMID:23297683

  3. Mature-stem expression of a silencing-resistant sucrose isomerase gene drives isomaltulose accumulation to high levels in sugarcane.

    PubMed

    Mudge, Stephen R; Basnayake, Shiromi W V; Moyle, Richard L; Osabe, Kenji; Graham, Michael W; Morgan, Terence E; Birch, Robert G

    2013-05-01

    Isomaltulose (IM) is a natural isomer of sucrose. It is widely approved as a food with properties including slower digestion, lower glycaemic index and low cariogenicity, which can benefit consumers. Availability is currently limited by the cost of fermentative conversion from sucrose. Transgenic sugarcane plants with developmentally-controlled expression of a silencing-resistant gene encoding a vacuole-targeted IM synthase were tested under field conditions typical of commercial sugarcane cultivation. High yields of IM were obtained, up to 483 mm or 81% of total sugars in whole-cane juice from plants aged 13 months. Using promoters from sugarcane to drive expression preferentially in the sugarcane stem, IM levels were consistent between stalks and stools within a transgenic line and across consecutive vegetative field generations of tested high-isomer lines. Germination and early growth of plants from setts were unaffected by IM accumulation, up to the tested level around 500 mm in flanking stem internodes. These are the highest yields ever achieved of value-added materials through plant metabolic engineering. The sugarcane stem promoters are promising for strategies to achieve even higher IM levels and for other applications in sugarcane molecular improvement. Silencing-resistant transgenes are critical to deliver the potential of these promoters in practical sugarcane improvement. At the IM levels now achieved in field-grown sugarcane, direct production of IM in plants is feasible at a cost approaching that of sucrose, which should make the benefits of IM affordable on a much wider scale.

  4. Artemisinin-Resistant Plasmodium falciparum Parasites Exhibit Altered Patterns of Development in Infected Erythrocytes

    PubMed Central

    Hott, Amanda; Casandra, Debora; Sparks, Kansas N.; Morton, Lindsay C.; Castanares, Geocel-Grace; Rutter, Amanda

    2015-01-01

    Artemisinin derivatives are used in combination with other antimalarial drugs for treatment of multidrug-resistant malaria worldwide. Clinical resistance to artemisinin recently emerged in southeast Asia, yet in vitro phenotypes for discerning mechanism(s) of resistance remain elusive. Here, we describe novel phenotypic resistance traits expressed by artemisinin-resistant Plasmodium falciparum. The resistant parasites exhibit altered patterns of development that result in reduced exposure to drug at the most susceptible stage of development in erythrocytes (trophozoites) and increased exposure in the most resistant stage (rings). In addition, a novel in vitro delayed clearance assay (DCA) that assesses drug effects on asexual stages was found to correlate with parasite clearance half-life in vivo as well as with mutations in the Kelch domain gene associated with resistance (Pf3D7_1343700). Importantly, all of the resistance phenotypes were stable in cloned parasites for more than 2 years without drug pressure. The results demonstrate artemisinin-resistant P. falciparum has evolved a novel mechanism of phenotypic resistance to artemisinin drugs linked to abnormal cell cycle regulation. These results offer insights into a novel mechanism of drug resistance in P. falciparum and new tools for monitoring the spread of artemisinin resistance. PMID:25779582

  5. CytA enables CryIV endotoxins of Bacillus thuringiensis to overcome high levels of CryIV resistance in the mosquito, Culex quinquefasciatus

    PubMed Central

    Wirth, M. C.; Georghiou, G. P.; Federici, B. A.

    1997-01-01

    Cry proteins produced by Bacillus thuringiensis are selective biodegradable insecticides used increasingly in bacterial insecticides and transgenic plants as alternatives to synthetic chemical insecticides. However, the potential for development of resistance and cross-resistance in target insect populations to Cry proteins used alone or in combination threatens the more widespread use of this novel pest control technology. Here we show that high levels of resistance to CryIV proteins in larvae of the mosquito, Culex quinquefasciatus, can be suppressed or reduced markedly by combining these proteins with sublethal quantities of CytA, a cytolytic endotoxin of B. thuringiensis. Resistance at the LC95 level of 127-fold for a combination of three CryIV toxins (CryIVA, B, and D), resulting from 60 generations of continuous selection, was completely suppressed by combining sporulated powders of CytA in a 1:3 ratio with sporulated powders of a CryIVA, CryIVB, and CryIVD strain. Combining the CytA strain with a CryIVA and CryIVB strain also completely suppressed mosquito resistance of 217-fold to the latter toxins at the LC95 level, whereas combination of CytA with CryIVD reduced resistance in a CryIVD-selected mosquito strain from greater than 1,000-fold to less than 8-fold. The CytA/CryIV model provides a potential molecular genetic strategy for engineering resistance management for Cry proteins directly into bacterial insecticides and transgenic plants. PMID:9380670

  6. CytA enables CryIV endotoxins of Bacillus thuringiensis to overcome high levels of CryIV resistance in the mosquito, Culex quinquefasciatus.

    PubMed

    Wirth, M C; Georghiou, G P; Federici, B A

    1997-09-30

    Cry proteins produced by Bacillus thuringiensis are selective biodegradable insecticides used increasingly in bacterial insecticides and transgenic plants as alternatives to synthetic chemical insecticides. However, the potential for development of resistance and cross-resistance in target insect populations to Cry proteins used alone or in combination threatens the more widespread use of this novel pest control technology. Here we show that high levels of resistance to CryIV proteins in larvae of the mosquito, Culex quinquefasciatus, can be suppressed or reduced markedly by combining these proteins with sublethal quantities of CytA, a cytolytic endotoxin of B. thuringiensis. Resistance at the LC95 level of 127-fold for a combination of three CryIV toxins (CryIVA, B, and D), resulting from 60 generations of continuous selection, was completely suppressed by combining sporulated powders of CytA in a 1:3 ratio with sporulated powders of a CryIVA, CryIVB, and CryIVD strain. Combining the CytA strain with a CryIVA and CryIVB strain also completely suppressed mosquito resistance of 217-fold to the latter toxins at the LC95 level, whereas combination of CytA with CryIVD reduced resistance in a CryIVD-selected mosquito strain from greater than 1,000-fold to less than 8-fold. The CytA/CryIV model provides a potential molecular genetic strategy for engineering resistance management for Cry proteins directly into bacterial insecticides and transgenic plants.

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

    PubMed

    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.

  8. Fitness Costs and Stability of a High-Level Ciprofloxacin Resistance Phenotype in Salmonella enterica Serotype Enteritidis: Reduced Infectivity Associated with Decreased Expression of Salmonella Pathogenicity Island 1 Genes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fitness costs associated with high-level fluoroquinolone resistance were examined in phenotypically and genotypically characterized ciprofloxacin-resistant Salmonella Enteritidis mutants (104-cip and 5408-cip, MIC > 32 µg/ml). The stability of the fluoroquinolone resistance phenotype in both mut...

  9. FECAL SOURCE TRACKING BY ANTIBIOTIC RESISTANCE ANALYSIS ON A WATERSHED EXHIBITING LOW RESISTANCE

    EPA Science Inventory

    The ongoing development of microbial source tracking has made it possible to identify contamination sources with varying accuracy, depending on the method used. The purpose of this study was done to test the efficiency of the antibiotic resistance analysis (ARA) method under low ...

  10. Diversity of enterococcal species and characterization of high-level aminoglycoside resistant enterococci of samples of wastewater and surface water in Tunisia.

    PubMed

    Ben Said, Leila; Klibi, Naouel; Lozano, Carmen; Dziri, Raoudha; Ben Slama, Karim; Boudabous, Abdellatif; Torres, Carmen

    2015-10-15

    One hundred-fourteen samples of wastewater (n=64) and surface-water (n=50) were inoculated in Slanetz-Bartley agar plates supplemented or not with gentamicin (SB-Gen and SB plates, respectively) for enterococci recovery. Enterococci were obtained from 75% of tested samples in SB media (72% in wastewater; 78% in surface-water), and 85 enterococcal isolates (one/positive-sample) were obtained. Enterococcus faecium was the most prevalent species (63.5%), followed by Enterococcus faecalis (20%), Enterococcus hirae (9.4%), Enterococcus casseliflavus (4.7%), and Enterococcus gallinarum/Enterococcus durans (2.4%). Antibiotic resistance detected among these enterococci was as follows [percentage/detected gene (number isolates)]: kanamycin [29%/aph(3')-IIIa (n=22)], streptomycin [8%/ant(6)-Ia (n=4)], erythromycin [44%/erm(B) (n=34)], tetracycline [18%/tet(M) (n=6)/tet(M)-tet(L) (n=9)], chloramphenicol [2%/cat(A) (n=1)], ciprofloxacin [7%] and trimethoprim-sulfamethoxazole [94%]. High-level-gentamicin resistant (HLR-G) enterococci were recovered from 15 samples in SB-Gen or SB plates [12/64 samples of wastewater (19%) and 3/50 samples of surface-water (6%)]; HLR-G isolates were identified as E. faecium (n=7), E. faecalis (n=6), and E. casseliflavus (n=2). These HLR-G enterococci carried the aac(6')-Ie-aph(2")-Ia and erm(B) genes, in addition to aph(3')-IIIa (n=10), ant(6)-Ia (n=9), tet(M) (n=13), tet(L) (n=8) and cat(A) genes (n=2). Three HLR-G enterococci carried the esp virulence gene. Sequence-types detected among HLR-G enterococci were as follows: E. faecalis (ST480, ST314, ST202, ST55, and the new ones ST531 and ST532) and E. faecium (ST327, ST12, ST296, and the new ones ST985 and ST986). Thirty-two different PFGE patterns were detected among 36 high-level-aminoglycoside-resistant enterococci recovered in water samples. Diverse genetic lineages of HLR-G enterococci were detected in wastewater and surface-water in Tunisia. Water can represent an important source for the

  11. High-level azithromycin resistance occurs in Neisseria gonorrhoeae as a result of a single point mutation in the 23S rRNA genes.

    PubMed

    Chisholm, Stephanie A; Dave, Jayshree; Ison, Catherine A

    2010-09-01

    High-level azithromycin resistance (AZM-HR), defined as a MIC of > or = 256 mg/liter, emerged in Neisseria gonorrhoeae in the United Kingdom in 2004. To determine the mechanism of this novel phenotype, isolates from the United Kingdom that were AZM-HR (n, 19), moderately AZM resistant (MICs, 2 to 8 mg/liter) (n, 26), or sensitive (MICs, 0.12 to 0.25 mg/liter) (n, 4) were screened for methylase (erm) genes and for mutations in the mtrR promoter region, associated with efflux pump upregulation. All AZM-resistant isolates and 12 sensitive isolates were screened for mutations in domain V of each 23S rRNA allele. All AZM-HR isolates contained the A2059G mutation (Escherichia coli numbering) in three (3 isolates) or four (16 isolates) 23S rRNA alleles. Most (22/26) moderately AZM resistant isolates contained the C2611T mutation in at least 3/4 alleles. The remainder contained four wild-type alleles, as did 8/12 sensitive isolates, while one allele was mutated in the remaining four sensitive isolates. Serial passage of AZM-sensitive colonies on an erythromycin-containing medium selected AZM-HR if the parent strain already contained mutation A2059G in one 23S rRNA allele. The resultant AZM-HR strains contained four mutated alleles. Eight isolates (five moderately AZM resistant and three AZM-HR) contained mutations in the mtrR promoter. No methylase genes were detected. This is the first evidence that AZM-HR in gonococci may result from a single point mutation (A2059G) in the peptidyltransferase loop in domain V of the 23S rRNA gene. Mutation of a single allele is insufficient to confer AZM-HR, but AZM-HR can develop under selection pressure. The description of a novel resistance mechanism will aid in screening for the AZM-HR phenotype. PMID:20585125

  12. Circulating tumor cells exhibit a biologically aggressive cancer phenotype accompanied by selective resistance to chemotherapy.

    PubMed

    Pavese, Janet M; Bergan, Raymond C

    2014-10-01

    With prostate cancer (PCa), circulating tumor cells (CTCs) and disseminated tumor cells (DTCs) portend a poor clinical prognosis. Their unknown biology precludes rational therapeutic design. We demonstrate that CTC and DTC cell lines, established from mice bearing human PCa orthotopic implants, exhibit increased cellular invasion in vitro, increased metastasis in mice, and express increased epithelial to mesenchymal transition biomarkers. Further, they are selectively resistant to growth inhibition by mitoxantrone-like agents. These findings demonstrate that CTC formation is accompanied by phenotypic progression without obligate reversion. Their increased metastatic potential, selective therapeutic resistance, and differential expression of potential therapeutic targets provide a rational basis to test further interventions.

  13. An Upstream Truncation of the furA-katG Operon Confers High-Level Isoniazid Resistance in a Mycobacterium tuberculosis Clinical Isolate with No Known Resistance-Associated Mutations

    PubMed Central

    Yam, Wing Cheong; Zhang, Ying; Kao, Richard Y. T.

    2014-01-01

    Although the major causes of isoniazid (INH) resistance in Mycobacterium tuberculosis are confined to structural mutations in katG and promoter mutations in the mabA-inhA operon, a significant proportion of INH-resistant strains have unknown resistance mechanisms. Recently, we identified a high-level INH-resistant M. tuberculosis clinical isolate, GB005, with no known resistance-associated mutations. A comprehensive study was performed to investigate the molecular basis of drug resistance in this strain. Although no mutations were found throughout the katG and furA-katG intergenic region, the katG expression and the catalase activity were greatly diminished compared to those in H37Rv (P < 0.01). Northern blotting revealed that the katG transcript from the isolate was smaller than that of H37Rv. Sequencing analysis of furA and upstream genes discovered a 7.2-kb truncation extended from the 96th base preceding the initiation codon of katG. Complementation of the M. tuberculosis Δ(furA-katG) strain with katG and different portions of the truncated region identified a 134-bp upstream fragment of furA that was essential for full catalase activity and INH susceptibility in M. tuberculosis. The promoter activity of this fragment was also shown to be stronger than that of the furA-katG intergenic region (P < 0.01). Collectively, these findings demonstrate that deletion of the 134-bp furA upstream fragment is responsible for the reduction in katG expression, resulting in INH resistance in GB005. To our knowledge, this is the first report showing that deletion of the upstream region preceding the furA-katG operon causes high-level INH resistance in a clinical isolate of M. tuberculosis. PMID:25092698

  14. Chloramphenicol- and tetracycline-resistant uropathogenic Escherichia coli (UPEC) exhibit reduced virulence potential.

    PubMed

    Starcic Erjavec, Marjanca; Rijavec, Matija; Krizan-Hergouth, Veronika; Fruth, Angelika; Zgur-Bertok, Darja

    2007-11-01

    It is well documented that uropathogenic Escherichia coli (UPEC) isolates resistant to nalidixic acid have reduced virulence potential. Our goal was to assess whether UPEC isolates resistant to chloramphenicol, tetracycline and streptomycin also exhibit reduced virulence potential. Among 110 human UPEC isolates, the prevalences of the virulence factors fimH, papC, papGII, papGIII, sfa/focDE, afa, hlyA, cnf1, usp, ibeA, fyuA, iroN, iucD, ireA, and K1 and K5 capsules as well as of pathotypes, phylogenetic groups, O antigens and a pathogenicity island (PAI) marker were compared between chloramphenicol-, tetracycline-, streptomycin- and, as a control, nalidixic acid-resistant and -susceptible strains. Our findings show that among human UPEC isolates, not only nalidixic acid-resistant but also chloramphenicol- and tetracycline-resistant isolates have reduced virulence potential compared with susceptible strains. To our knowledge, this is the first report of a statistically significant reduction in virulence traits among chloramphenicol- and tetracycline-resistant isolates.

  15. Transgenic Citrus Expressing an Arabidopsis NPR1 Gene Exhibit Enhanced Resistance against Huanglongbing (HLB; Citrus Greening)

    PubMed Central

    Dutt, Manjul; Barthe, Gary; Irey, Michael; Grosser, Jude

    2015-01-01

    Commercial sweet orange cultivars lack resistance to Huanglongbing (HLB), a serious phloem limited bacterial disease that is usually fatal. In order to develop sustained disease resistance to HLB, transgenic sweet orange cultivars ‘Hamlin’ and ‘Valencia’ expressing an Arabidopsis thaliana NPR1 gene under the control of a constitutive CaMV 35S promoter or a phloem specific Arabidopsis SUC2 (AtSUC2) promoter were produced. Overexpression of AtNPR1 resulted in trees with normal phenotypes that exhibited enhanced resistance to HLB. Phloem specific expression of NPR1 was equally effective for enhancing disease resistance. Transgenic trees exhibited reduced diseased severity and a few lines remained disease-free even after 36 months of planting in a high-disease pressure field site. Expression of the NPR1 gene induced expression of several native genes involved in the plant defense signaling pathways. The AtNPR1 gene being plant derived can serve as a component for the development of an all plant T-DNA derived consumer friendly GM tree. PMID:26398891

  16. Exposing a β-Lactamase “Twist”: the Mechanistic Basis for the High Level of Ceftazidime Resistance in the C69F Variant of the Burkholderia pseudomallei PenI β-Lactamase

    PubMed Central

    Becka, Scott A.; Taracila, Magdalena A.; Winkler, Marisa L.; Gatta, Julian A.; Rholl, Drew A.; Schweizer, Herbert P.

    2015-01-01

    Around the world, Burkholderia spp. are emerging as pathogens highly resistant to β-lactam antibiotics, especially ceftazidime. Clinical variants of Burkholderia pseudomallei possessing the class A β-lactamase PenI with substitutions at positions C69 and P167 are known to demonstrate ceftazidime resistance. However, the biochemical basis for ceftazidime resistance in class A β-lactamases in B. pseudomallei is largely undefined. Here, we performed site saturation mutagenesis of the C69 position and investigated the kinetic properties of the C69F variant of PenI from B. pseudomallei that results in a high level of ceftazidime resistance (2 to 64 mg/liter) when expressed in Escherichia coli. Surprisingly, quantitative immunoblotting showed that the steady-state protein levels of the C69F variant β-lactamase were ∼4-fold lower than those of wild-type PenI (0.76 fg of protein/cell versus 4.1 fg of protein/cell, respectively). However, growth in the presence of ceftazidime increases the relative amount of the C69F variant to greater than wild-type PenI levels. The C69F variant exhibits a branched kinetic mechanism for ceftazidime hydrolysis, suggesting there are two different conformations of the enzyme. When incubated with an anti-PenI antibody, one conformation of the C69F variant rapidly hydrolyzes ceftazidime and most likely contributes to the higher levels of ceftazidime resistance observed in cell-based assays. Molecular dynamics simulations suggest that the electrostatic characteristics of the oxyanion hole are altered in the C69F variant. When ceftazidime was positioned in the active site, the C69F variant is predicted to form a greater number of hydrogen-bonding interactions than PenI with ceftazidime. In conclusion, we propose “a new twist” for enhanced ceftazidime resistance mediated by the C69F variant of the PenI β-lactamase based on conformational changes in the C69F variant. Our findings explain the biochemical basis of ceftazidime resistance in

  17. A Multicenter Study of Beta-Lactamase Resistant Escherichia coli and Klebsiella pneumoniae Reveals High Level Chromosome Mediated Extended Spectrum β Lactamase Resistance in Ogun State, Nigeria

    PubMed Central

    Adeyankinnu, Folasoge A.; Motayo, Babatunde O.; Akinduti, Akinniyi; Akinbo, John; Ogiogwa, Joseph I.; Aboderin, Bukola W.; Agunlejika, R. A.

    2014-01-01

    As a result of the ever increasing problem of multiresistant bacteria, we instituted a surveillance program with the aim of identifying the basic molecular properties of ESBL in our environment. About 197 isolates of Escherichia coli and Klebsiella pneumoniae were selected and tested for ESBL production and antimicrobial susceptibility. Plasmid profiles were determined and curing ability was tested. ESBL prevalence was 26.4% for all isolates tested, with E. coli having a greater proportion. There was absolute resistance to ampicilin, tetracycline, and co-trimaxole among tested isolates. There was above average susceptibility to the 2nd and 3rd generation cephalosporins. Plasmid profiles of tested isolates ranged from 9 kbp to 26 kbp with average of 14.99 ± 2.3 kbp for E. coli and 20.98 ± 1.8 kbp K. pneumoniae, 9.6% of ESBL positive E. coli plasmids were cured, while 3.9% of K. pneumoniae plasmids were cured after treatment. The present study shows an upsurge in ESBL acquisition by gram negative bacteria and evidence of cocirculation of varying subtypes of ESBL with both plasmid transmissible and chromosome encoded subtypes. This calls for universal surveillance and more effort towards molecular epidemiology of this public health treatment. PMID:24790598

  18. Cognitively impaired elderly exhibit insulin resistance and no memory improvement with infused insulin.

    PubMed

    Morris, Jill K; Vidoni, Eric D; Mahnken, Jonathan D; Montgomery, Robert N; Johnson, David K; Thyfault, John P; Burns, Jeffrey M

    2016-03-01

    Insulin resistance is a risk factor for Alzheimer's disease (AD), although its role in AD etiology is unclear. We assessed insulin resistance using fasting and insulin-stimulated measures in 51 elderly subjects with no dementia (ND; n = 37) and with cognitive impairment (CI; n = 14). CI subjects exhibited either mild CI or AD. Fasting insulin resistance was measured using the homeostatic model assessment of insulin resistance (HOMA-IR). Insulin-stimulated glucose disposal was assessed using the hyperinsulinemic-euglycemic clamp to calculate glucose disposal rate into lean mass, the primary site of insulin-stimulated glucose disposal. Because insulin crosses the blood-brain barrier, we also assessed whether insulin infusion would improve verbal episodic memory compared to baseline. Different but equivalent versions of cognitive tests were administered in counterbalanced order in the basal and insulin-stimulated state. Groups did not differ in age or body mass index. Cognitively impaired subjects exhibited greater insulin resistance as measured at fasting (HOMA-IR; ND: 1.09 [1.1] vs. CI: 2.01 [2.3], p = 0.028) and during the hyperinsulinemic clamp (glucose disposal rate into lean mass; ND: 9.9 (4.5) vs. AD 7.2 (3.2), p = 0.040). Cognitively impaired subjects also exhibited higher fasting insulin compared to ND subjects, (CI: 8.7 [7.8] vs. ND: 4.2 [3.8] μU/mL; p = 0.023) and higher fasting amylin (CI: 24.1 [39.1] vs. 8.37 [14.2]; p = 0.050) with no difference in fasting glucose. Insulin infusion elicited a detrimental effect on one test of verbal episodic memory (Free and Cued Selective Reminding Test) in both groups (p < 0.0001) and no change in performance on an additional task (delayed logical memory). In this study, although insulin resistance was observed in cognitively impaired subjects compared to ND controls, insulin infusion did not improve memory. Furthermore, a significant correlation between HOMA-IR and glucose disposal rate was present only in ND

  19. Electrical transport properties of TiCoSb half-Heusler phases that exhibit high resistivity

    NASA Astrophysics Data System (ADS)

    Xia, Y.; Ponnambalam, V.; Bhattacharya, S.; Pope, A. L.; Poon, S. J.; Tritt, T. M.

    2001-01-01

    Electrical transport measurements have been performed on doped and undoped TiCoSb half-Heusler phases. The semiconducting properties are found to be more robust than those reported for MNiSn (M = Ti, Zr, Hf ). Undoped TiCoSb phases exhibit large n-type Seebeck coefficients and high resistivities that reach -500 µV K-1 at 300 K and ~1500 Ω cm at 4.2 K, respectively. A tendency towards carrier localization is seen in several disordered phases. The effects due to n-type and p-type dopants are readily manifested in the thermopower, from which moderately heavy electron and hole band masses are inferred. The unusual properties measured are consistent with the prediction of a wide bandgap for the TiCoSb phase. A resistivity minimum is observed at 500-600 K for undoped and V-doped TiCoSb. Consequently, the semiconducting gap has not been determined.

  20. High-temperature corrosion-resistant iron-aluminide (FeAl) alloys exhibiting improved weldability

    DOEpatents

    Maziasz, Philip J.; Goodwin, Gene M.; Liu, Chain T.

    1996-01-01

    This invention relates to improved corrosion-resistant iron-aluminide intermetallic alloys. The alloys of this invention comprise, in atomic percent, from about 30% to about 40% aluminum alloyed with from about 0.1% to about 0.5% carbon, no more than about 0.04% boron such that the atomic weight ratio of boron to carbon in the alloy is in the range of from about 0.01:1 to about 0.08:1, from about 0.01 to about 3.5% of one or more transition metals selected from Group IVB, VB, and VIB elements and the balance iron wherein the alloy exhibits improved resistance to hot cracking during welding.

  1. High-temperature corrosion-resistant iron-aluminide (FeAl) alloys exhibiting improved weldability

    DOEpatents

    Maziasz, P.J.; Goodwin, G.M.; Liu, C.T.

    1996-08-13

    This invention relates to improved corrosion-resistant iron-aluminide intermetallic alloys. The alloys of this invention comprise, in atomic percent, from about 30% to about 40% aluminum alloyed with from about 0.1% to about 0.5% carbon, no more than about 0.04% boron such that the atomic weight ratio of boron to carbon in the alloy is in the range of from about 0.01:1 to about 0.08:1, from about 0.01 to about 3.5% of one or more transition metals selected from Group IVB, VB, and VIB elements and the balance iron wherein the alloy exhibits improved resistance to hot cracking during welding. 13 figs.

  2. CPRMethicillin resistant coagulase-negative staphylococci isolated from South Korean ducks exhibiting tremor

    PubMed Central

    2013-01-01

    Background We describe coagulase-negative staphylococci (CoNS) isolates collected from ducklings exhibiting tremor in South Korea over the period of 2010 to 2011. Screening of antimicrobial susceptibility and analysis of SCCmec elements of CoNS were also investigated. Results Staphylococcus cohnii was the most frequent staphylococcus (9 isolates) and S. sciuri (4 isolates), S. lentus (3 isolate), S. simulans (1 isolate) and S. epidermidis (1 isolate) were also detected. Among the 15 antimicrobials tested in this study, resistance against oxacillin (15 isolates, 83.3%) was most frequently observed, but only one isolate (SNUDS-1) possessed mecA. This isolate was shown to possess SCCmec type III; the type 3 ccr complex and the class A mec complex. Conclusions Based on these results, isolate SNUDS-1 was shown to possess SCCmec type III; the type 3 ccr complex and the class A mec complex. Although the SCCmec type III is not predominant in human, MR-CoNS (Methicillin resistance Coagulase-negative staphylococci) in food animals should be monitored to prevent the dissemination of antimicrobial resistance genes and resistant pathogens to the community. PMID:24330456

  3. Cells surviving fractional killing by TRAIL exhibit transient but sustainable resistance and inflammatory phenotypes

    PubMed Central

    Flusberg, Deborah A.; Roux, Jérémie; Spencer, Sabrina L.; Sorger, Peter K.

    2013-01-01

    When clonal populations of human cells are exposed to apoptosis-inducing agents, some cells die and others survive. This fractional killing arises not from mutation but from preexisting, stochastic differences in the levels and activities of proteins regulating apoptosis. Here we examine the properties of cells that survive treatment with agonists of two distinct death receptors, tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) and anti-FasR antibodies. We find that “survivor” cells are highly resistant to a second ligand dose applied 1 d later. Resistance is reversible, resetting after several days of culture in the absence of death ligand. “Reset” cells appear identical to drug-naive cells with respect to death ligand sensitivity and gene expression profiles. TRAIL survivors are cross-resistant to activators of FasR and vice versa and exhibit an NF-κB–dependent inflammatory phenotype. Remarkably, reversible resistance is induced in the absence of cell death when caspase inhibitors are present and can be sustained for 1 wk or more, also without cell death, by periodic ligand exposure. Thus stochastic differences in cell state can have sustained consequences for sen­sitivity to prodeath ligands and acquisition of proinflammatory phenotypes. The important role played by periodicity in TRAIL exposure for induction of opposing apoptosis and survival mechanisms has implications for the design of optimal therapeutic agents and protocols. PMID:23699397

  4. High-level hemicellulosic arabinose predominately affects lignocellulose crystallinity for genetically enhancing both plant lodging resistance and biomass enzymatic digestibility in rice mutants.

    PubMed

    Li, Fengcheng; Zhang, Mingliang; Guo, Kai; Hu, Zhen; Zhang, Ran; Feng, Yongqing; Yi, Xiaoyan; Zou, Weihua; Wang, Lingqiang; Wu, Changyin; Tian, Jinshan; Lu, Tiegang; Xie, Guosheng; Peng, Liangcai

    2015-05-01

    Rice is a major food crop with enormous biomass residue for biofuels. As plant cell wall recalcitrance basically decides a costly biomass process, genetic modification of plant cell walls has been regarded as a promising solution. However, due to structural complexity and functional diversity of plant cell walls, it becomes essential to identify the key factors of cell wall modifications that could not much alter plant growth, but cause an enhancement in biomass enzymatic digestibility. To address this issue, we performed systems biology analyses of a total of 36 distinct cell wall mutants of rice. As a result, cellulose crystallinity (CrI) was examined to be the key factor that negatively determines either the biomass enzymatic saccharification upon various chemical pretreatments or the plant lodging resistance, an integrated agronomic trait in plant growth and grain production. Notably, hemicellulosic arabinose (Ara) was detected to be the major factor that negatively affects cellulose CrI probably through its interlinking with β-1,4-glucans. In addition, lignin and G monomer also exhibited the positive impact on biomass digestion and lodging resistance. Further characterization of two elite mutants, Osfc17 and Osfc30, showing normal plant growth and high biomass enzymatic digestion in situ and in vitro, revealed the multiple GH9B candidate genes for reducing cellulose CrI and XAT genes for increasing hemicellulosic Ara level. Hence, the results have suggested the potential cell wall modifications for enhancing both biomass enzymatic digestibility and plant lodging resistance by synchronically overexpressing GH9B and XAT genes in rice.

  5. Antimicrobial resistance and molecular typing of Neisseria gonorrhoeae isolates in Kyoto and Osaka, Japan, 2010 to 2012: intensified surveillance after identification of the first strain (H041) with high-level ceftriaxone resistance.

    PubMed

    Shimuta, Ken; Unemo, Magnus; Nakayama, Shu-Ichi; Morita-Ishihara, Tomoko; Dorin, Misato; Kawahata, Takuya; Ohnishi, Makoto

    2013-11-01

    In 2009, the first high-level ceftriaxone-resistant Neisseria gonorrhoeae strain (H041) was isolated in Kyoto, Japan. The present study describes an intensified surveillance (antimicrobial resistance and molecular typing) of Neisseria gonorrhoeae isolates in Kyoto and its neighboring prefecture Osaka, Japan, in 2010 to 2012, which was initiated after the identification of H041. From April 2010 to March 2012, 193 N. gonorrhoeae isolates were collected and the MICs (μg/ml) to six antimicrobials, including ceftriaxone, were determined. All isolates showed susceptibility to ceftriaxone and cefixime (MIC values, <0.5 μg/ml), and spectinomycin. The rates of resistance (intermediate susceptibility) to azithromycin, penicillin G, and ciprofloxacin were 3.6% (19.7%), 24.4% (71.0%), and 78.2% (0.5%), respectively. Multilocus sequence typing (MLST) showed that 40.9%, 19.2%, and 17.1% of isolates belonged to ST1901, ST7359, and ST7363, respectively. Furthermore, N. gonorrhoeae multiantigen sequence typing (NG-MAST) revealed that 12 (63%) of the 19 isolates with decreased susceptibility to ceftriaxone (MIC > 0.064 μg/ml) were of ST1407. NG-MAST ST1407 was also the most prevalent ST (16.1%; 31 of 193 isolates). In those NG-MAST ST1407 strains, several mosaic type penA alleles were found, including SF-A type (penicillin binding protein 2 allele XXXIV) and its derivatives. These were confirmed using transformation of the penA mosaic alleles as critical determinants for enhanced cefixime and ceftriaxone MICs. The intensified surveillance in Kyoto and Osaka, Japan, did not identify any dissemination of the high-level ceftriaxone-resistant N. gonorrhoeae strain H041, suggesting that H041 might have caused only a sporadic case and has not spread further.

  6. Persistently betanodavirus-infected barramundi (Lates calcarifer) exhibit resistances to red sea bream iridovirus infection.

    PubMed

    Wu, Yu-Chi; Kai, Yu-Hsuan; Chi, Shau-Chi

    2013-12-01

    Nervous necrosis virus (NNV) and red sea bream iridovirus (RSIV) are two important pathogens that have caused acute, highly contagious, and widespread diseases among wild and cultured fish, especially at larval and juvenile stages. We discovered that the pathogenicity of NNV to the 80 days post-hatch (dph) barramundi is lower than that to the 14 dph barramundi. Following NNV challenge, no mortality occurred in the 80 dph barramundi, but NNV RNA2 and barramundi Mx (BMx) gene expression was detected in the brain and liver. The 80 dph barramundi pre-challenged with NNV became more resistant to the following RSIV challenge (mortality: 62%) compared to the NNV-free barramundi challenged with RSIV (mortality: 100%). A similar phenomenon was revealed in the cell culture system that RSIV proliferated less progeny in the barramundi brain (BB) cell line which exhibit persistent NNV infection than in NNV-free cured BB (cBB) cell line. The potential factors involved in the resistance of the persistently NNV-infected barramundi and BB cells to the secondary RSIV infection were examined in this study. We prove that barramundi anti-NNV polyclonal antibodies do not cross-neutralize RSIV, and NNV infection does not interfere with RSIV replication. However, the interferon (IFN) response and BMx gene expression in cBB cells suppresses the RSIV proliferation. Our study suggests that the NNV-induced IFN response and BMx expression are responsible for the resistance of barramundi to RSIV infection. PMID:23831937

  7. Grizzly bears exhibit augmented insulin sensitivity while obese prior to a reversible insulin resistance during hibernation.

    PubMed

    Nelson, O Lynne; Jansen, Heiko T; Galbreath, Elizabeth; Morgenstern, Kurt; Gehring, Jamie Lauren; Rigano, Kimberly Scott; Lee, Jae; Gong, Jianhua; Shaywitz, Adam J; Vella, Chantal A; Robbins, Charles T; Corbit, Kevin C

    2014-08-01

    The confluence of obesity and diabetes as a worldwide epidemic necessitates the discovery of new therapies. Success in this endeavor requires translatable preclinical studies, which traditionally employ rodent models. As an alternative approach, we explored hibernation where obesity is a natural adaptation to survive months of fasting. Here we report that grizzly bears exhibit seasonal tripartite insulin responsiveness such that obese animals augment insulin sensitivity but only weeks later enter hibernation-specific insulin resistance (IR) and subsequently reinitiate responsiveness upon awakening. Preparation for hibernation is characterized by adiposity coupled to increased insulin sensitivity via modified PTEN/AKT signaling specifically in adipose tissue, suggesting a state of "healthy" obesity analogous to humans with PTEN haploinsufficiency. Collectively, we show that bears reversibly cope with homeostatic perturbations considered detrimental to humans and describe a mechanism whereby IR functions not as a late-stage metabolic adaptation to obesity, but rather a gatekeeper of the fed-fasting transition.

  8. Grizzly bears exhibit augmented insulin sensitivity while obese prior to a reversible insulin resistance during hibernation.

    PubMed

    Nelson, O Lynne; Jansen, Heiko T; Galbreath, Elizabeth; Morgenstern, Kurt; Gehring, Jamie Lauren; Rigano, Kimberly Scott; Lee, Jae; Gong, Jianhua; Shaywitz, Adam J; Vella, Chantal A; Robbins, Charles T; Corbit, Kevin C

    2014-08-01

    The confluence of obesity and diabetes as a worldwide epidemic necessitates the discovery of new therapies. Success in this endeavor requires translatable preclinical studies, which traditionally employ rodent models. As an alternative approach, we explored hibernation where obesity is a natural adaptation to survive months of fasting. Here we report that grizzly bears exhibit seasonal tripartite insulin responsiveness such that obese animals augment insulin sensitivity but only weeks later enter hibernation-specific insulin resistance (IR) and subsequently reinitiate responsiveness upon awakening. Preparation for hibernation is characterized by adiposity coupled to increased insulin sensitivity via modified PTEN/AKT signaling specifically in adipose tissue, suggesting a state of "healthy" obesity analogous to humans with PTEN haploinsufficiency. Collectively, we show that bears reversibly cope with homeostatic perturbations considered detrimental to humans and describe a mechanism whereby IR functions not as a late-stage metabolic adaptation to obesity, but rather a gatekeeper of the fed-fasting transition. PMID:25100064

  9. High level nuclear waste

    SciTech Connect

    Crandall, J L

    1980-01-01

    The DOE Division of Waste Products through a lead office at Savannah River is developing a program to immobilize all US high-level nuclear waste for terminal disposal. DOE high-level wastes include those at the Hanford Plant, the Idaho Chemical Processing Plant, and the Savannah River Plant. Commercial high-level wastes, for which DOE is also developing immobilization technology, include those at the Nuclear Fuel Services Plant and any future commercial fuels reprocessing plants. The first immobilization plant is to be the Defense Waste Processing Facility at Savannah River, scheduled for 1983 project submission to Congress and 1989 operation. Waste forms are still being selected for this plant. Borosilicate glass is currently the reference form, but alternate candidates include concretes, calcines, other glasses, ceramics, and matrix forms.

  10. New chromogenic dipeptide substrate for continuous assay of the D-alanyl-D-alanine dipeptidase VanX required for high-level vancomycin resistance.

    PubMed

    Anissimova, M; Yaouancq, L; Noor, F; Badet-Denisot, M-A; Badet, B

    2003-08-01

    A direct continuous UV-Vis spectrophotometric assay has been developed for VanX, a D-alanyl-D-alanine aminodipeptidase necessary for vancomycin resistance. This method is based on the hydrolysis of the alternative substrate D-alanyl-alpha-(R)-phenylthio-glycine D-Ala-D-Gly(S-Ph)-OH (H-DAla-DPsg-OH, 5a). Spontaneous decomposition of the released phenylthioglycine generates thiophenol, which is quantified using Ellman's reagent. The dipeptide behaved as an excellent substrate of VanX, exhibiting Michaelis-Menten kinetics with a kcat of 76 +/- 5/s and a KM of 0.83 +/- 0.08 mm (kcat = 46 +/- 3/s and KM = 0.11 +/- 0.01 mm for D-Ala-D-Ala). Determination of the kinetic parameters of the previously reported mechanism-based inhibitor D-Ala-D-Gly(SPhip-CHF2)-OH (H-D-Ala-DPfg-OH, 5c) [Araoz, R., Anhalt, E., René, L., Badet-Denisot, M.-A., Courvalin, P. & Badet, B. (2000) Biochemistry 39, 15971-15979] using the substrate reported in the present study yielded values of Kirr of 22 +/- 1 microM and kinact of 9.3 +/- 0.4/min in good agreement with values previously obtained in our laboratory (Kirr = 30 +/- 1 mm; kinact = 7.3 +/- 0.3/min). In addition, inhibition by the competing substrate D-Ala-D-Ala resulted in determination of a Ki = 70 +/- 6 microM close to the previously reported KM value. These results demonstrate that the present assay is a convenient, rapid and sensitive tool in the search for VanX inhibitors.

  11. HIV-1 Protease with 20 Mutations Exhibits Extreme Resistance to Clinical Inhibitors through Coordinated Structural Rearrangements

    SciTech Connect

    Agniswamy, Johnson; Shen, Chen-Hsiang; Aniana, Annie; Sayer, Jane M.; Louis, John M.; Weber, Irene T.

    2012-06-28

    The escape mutant of HIV-1 protease (PR) containing 20 mutations (PR20) undergoes efficient polyprotein processing even in the presence of clinical protease inhibitors (PIs). PR20 shows >3 orders of magnitude decreased affinity for PIs darunavir (DRV) and saquinavir (SQV) relative to PR. Crystal structures of PR20 crystallized with yttrium, substrate analogue p2-NC, DRV, and SQV reveal three distinct conformations of the flexible flaps and diminished interactions with inhibitors through the combination of multiple mutations. PR20 with yttrium at the active site exhibits widely separated flaps lacking the usual intersubunit contacts seen in other inhibitor-free dimers. Mutations of residues 35-37 in the hinge loop eliminate interactions and perturb the flap conformation. Crystals of PR20/p2-NC contain one uninhibited dimer with one very open flap and one closed flap and a second inhibitor-bound dimer in the closed form showing six fewer hydrogen bonds with the substrate analogue relative to wild-type PR. PR20 complexes with PIs exhibit expanded S2/S2' pockets and fewer PI interactions arising from coordinated effects of mutations throughout the structure, in agreement with the strikingly reduced affinity. In particular, insertion of the large aromatic side chains of L10F and L33F alters intersubunit interactions and widens the PI binding site through a network of hydrophobic contacts. The two very open conformations of PR20 as well as the expanded binding site of the inhibitor-bound closed form suggest possible approaches for modifying inhibitors to target extreme drug-resistant HIV.

  12. ANAEROBIC RESISTANCE TO HIGH LEVELS OF CADMIUM AND OTHER TOXIC METALS IN A FACULTATIVE ANAEROBE ISOLATED FROM PRISTINE SALT MARSH SEDIMENTS

    SciTech Connect

    SHARMA,P.K.; VAIRAVAMURTHY,A.; KIELECZAWA,J.

    1999-06-20

    The authors have isolated many Cd (II) resistant bacterial strains from relatively pristine sediments collected from salt marshes in Shelter Island, New York. Detailed studies are being performed on one isolate, strain Cd-1. Strain Cd-1 is metabolically diverse, halotolerant, Gram-negative, facultative anaerobe. It can resist high amounts of Cd (II), Cr (VI), As (V), Se (IV), Co (II), Pb (II), or Zn (II) under defined anaerobic conditions. With pyruvate as the energy source, Cd-1 can grow well at examined Cd (II) concentrations ranging up to 15 mM. It can resist Cd (II) with or without marine level NaCl concentration, under acidic or neutral conditions. It can resist Cd (II) under aerobic conditions as well. These features are novel for a heavy metal resistant bacterium.

  13. The High Level of Aluminum Resistance in Signalgrass Is Not Associated with Known Mechanisms of External Aluminum Detoxification in Root Apices1

    PubMed Central

    Wenzl, Peter; Patiño, Gloria M.; Chaves, Alba L.; Mayer, Jorge E.; Rao, Idupulapati M.

    2001-01-01

    Al resistance of signalgrass (Brachiaria decumbens Stapf cv Basilisk), a widely sown tropical forage grass, is outstanding compared with the closely related ruzigrass (Brachiaria ruziziensis Germain and Evrard cv Common) and Al-resistant genotypes of graminaceous crops such as wheat, triticale, and maize. Secretion of organic acids and phosphate by root apices and alkalinization of the apical rhizosphere are commonly believed to be important mechanisms of Al resistance. However, root apices of signalgrass secreted only moderately larger quantities of organic acids than did those of ruzigrass, and efflux from signalgrass apices was three to 30 times smaller than from apices of Al-resistant genotypes of buckwheat, maize, and wheat (all much more sensitive to Al than signalgrass). In the presence, but not absence, of Al, root apices of signalgrass alkalinized the rhizosphere more than did those of ruzigrass. The latter was associated with a shortening of the alkalinizing zone in Al-intoxicated apices of ruzigrass, indicating that differences in alkalinizing power were a consequence, not a cause of, differential Al resistance. These data indicate that the main mechanism of Al resistance in signalgrass does not involve external detoxification of Al. Therefore, highly effective resistance mechanisms based on different physiological strategies appear to operate in this species. PMID:11244126

  14. Is Neisseria gonorrhoeae initiating a future era of untreatable gonorrhea?: detailed characterization of the first strain with high-level resistance to ceftriaxone.

    PubMed

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

    2011-07-01

    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.

  15. Pseudomonas aeruginosa High-Level Resistance to Polymyxins and Other Antimicrobial Peptides Requires cprA, a Gene That Is Disrupted in the PAO1 Strain

    PubMed Central

    Gutu, Alina D.; Rodgers, Nicole S.; Park, Jihye

    2015-01-01

    The arn locus, found in many Gram-negative bacterial pathogens, mediates resistance to polymyxins and other cationic antimicrobial peptides through 4-amino-l-arabinose modification of the lipid A moiety of lipopolysaccharide. In Pseudomonas aeruginosa, several two-component regulatory systems (TCSs) control the arn locus, which is necessary but not sufficient for these resistance phenotypes. A previous transposon mutagenesis screen to identify additional polymyxin resistance genes that these systems regulate implicated an open reading frame designated PA1559 in the genome of the P. aeruginosa PAO1 strain. Resequencing of this chromosomal region and bioinformatics analysis for a variety of P. aeruginosa strains revealed that in the sequenced PAO1 strain, a guanine deletion at the end of PA1559 results in a frameshift and truncation of a full-length open reading frame that also encompasses PA1560 in non-PAO1 strains, such as P. aeruginosa PAK. Deletion analysis in the PAK strain showed that this full-length open reading frame, designated cprA, is necessary for polymyxin resistance conferred by activating mutations in the PhoPQ, PmrAB, and CprRS TCSs. The cprA gene was also required for PmrAB-mediated resistance to other cationic antimicrobial peptides in the PAK strain. Repair of the mutated cprA allele in the PAO1 strain restored polymyxin resistance conferred by an activating TCS mutation. The deletion of cprA did not affect the arn-mediated lipid A modification, indicating that the CprA protein is necessary for a different aspect of polymyxin resistance. This protein has a domain structure with a strong similarity to the extended short-chain dehydrogenase/reductase family that comprises isomerases, lyases, and oxidoreductases. These results suggest a new avenue through which to pursue targeted inhibition of polymyxin resistance. PMID:26100714

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

    PubMed

    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. PMID:22552945

  17. Mutations in NalC induce MexAB-OprM overexpression resulting in high level of aztreonam resistance in environmental isolates of Pseudomonas aeruginosa.

    PubMed

    Braz, Vânia S; Furlan, João Pedro R; Fernandes, Ana Flavia T; Stehling, Eliana G

    2016-08-01

    Pseudomonas aeruginosa is an opportunistic pathogen with high resistance to a wide variety of antimicrobials. The multidrug resistance pump MexAB-OprM promotes the efflux of various antibiotics, mostly when mutations accumulate in the transcriptional regulators MexR, NalC and NalD, thereby causing MexAB-OprM overexpression. In this work, a characterization of 50 P. aeruginosa isolates obtained from Brazilian agricultural soils to determine the reasons of their resistance to aztreonam was done. The majority of the isolates showed higher aztreonam resistance than wild-type strain by MIC method. DNA sequence analysis of mexR, nalC and nalD genes from 13 of these isolates showed the amino acid substitution in NalC for all tested isolates, just one mutation was detected in MexR and none in NalD. Furthermore, an increase in the level of mexA expression by real-time RT-PCR analysis in eight isolates harboring mutations in NalC was found. Although there was not a relationship between MIC of aztreonam and the level of mexA expression, on the other hand, the results presented here suggest that novel mutations in NalC, including Arg97-Gly and Ala186-Thr, are related to MexAB-OprM overexpression causing aztreonam resistance in P. aeruginosa environmental isolates. PMID:27412168

  18. Characterization and growth of epitaxial layers of Gs exhibiting high resistivity for ionic implantation

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Either classical or low temperature epitaxial growth techniques can be used to control the deposition of buffer layers of GaAs on semiconducting substrates and to obtain the resistivity and purity desired. Techniques developed to study, as a function of thickness, the evolution of mobilities by photoHall, and the spectroscopy of shallow and deep centers by cathodoluminescence and current transients reveal one very pure layer of medium resistivity and high mobility, and another "dead layer" of elevated resistivity far from the surface. The highly resistive layer remains pure over several microns, which appears interesting for implantation.

  19. Mitigation of human-pathogenic fungi that exhibit resistance to medical agents: can clinical antifungal stewardship help?

    PubMed

    Hull, Claire M; Purdy, Nicola J; Moody, Suzy C

    2014-01-01

    Reducing indiscriminate antimicrobial usage to combat the expansion of multidrug-resistant human-pathogenic bacteria is fundamental to clinical antibiotic stewardship. In contrast to bacteria, fungal resistance traits are not understood to be propagated via mobile genetic elements, and it has been proposed that a global explosion of resistance to medical antifungals is therefore unlikely. Clinical antifungal stewardship has focused instead on reducing the drug toxicity and high costs associated with medical agents. Mitigating the problem of human-pathogenic fungi that exhibit resistance to antimicrobials is an emergent issue. This article addresses the extent to which clinical antifungal stewardship could influence the scale and epidemiology of resistance to medical antifungals both now and in the future. The importance of uncharted selection pressure exerted by agents outside the clinical setting (agricultural pesticides, industrial xenobiotics, biocides, pharmaceutical waste and others) on environmentally ubiquitous spore-forming molds that are lesserstudied but increasingly responsible for drug-refractory infections is considered.

  20. Spread of Escherichia coli Strains with High-Level Cefotaxime and Ceftazidime Resistance between the Community, Long-Term Care Facilities, and Hospital Institutions

    PubMed Central

    Oteo, Jesús; Navarro, Carmen; Cercenado, Emilia; Delgado-Iribarren, Alberto; Wilhelmi, Isabel; Orden, Beatriz; García, Carmen; Miguelañez, Silvia; Pérez-Vázquez, María; García-Cobos, Silvia; Aracil, Belén; Bautista, Verónica; Campos, José

    2006-01-01

    A total of 151 Escherichia coli strains resistant to cefotaxime and ceftazidime were isolated during a prospective surveillance study. These strains were characterized by clinical, microbiological, and molecular analyses and were distributed into four clusters of 103, 11, 6, and 5 isolates, along with 25 unrelated strains. The principal cluster was isolated from urine, wound, blood, and other samples in three hospitals, eight nursing homes, and a community healthcare center. This cluster was associated with both nosocomial (65%) and community-acquired (35%) infections. Most strains were resistant to ciprofloxacin, gentamicin, tobramycin, cefepime, amoxicillin-clavulanic acid, and trimethoprim-sulfamethoxazole but were susceptible to imipenem. All isolates from the four clusters expressed the extended-spectrum β-lactamase (ESBL) CTX-M-15. This enzyme was also present in 8 (30.8%) of the 26 unrelated isolates. The other ESBLs, CTX-M-14 and CTX-M-32, were detected in five and seven cases, respectively, but they were detected in individual E. coli isolates only. In three clusters, blaCTX-M-15 alleles were linked to an ISEcp1-like element, while in eight strains of cluster II an IS26 element preceded the blaCTX-M-15 allele. An additional pool of resistance genes included tetA, drfA14 or dfrA17, sul1 or sul2, aac(6′)Ib, and aac(3)IIb. All except one of the 27 isolates tested for genetic virulence markers harbored the same three virulence genes: iutA and fyuA (siderophores), and traT (serum survival factor). Epidemic or occasional isolates of cefotaxime- and ceftazidime-resistant E. coli can spread between distinct health facilities including hospitals, community health centers, and long-term care centers. PMID:16825350

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

    PubMed

    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.

  2. The efficacy of long-lasting nets with declining physical integrity may be compromised in areas with high levels of pyrethroid resistance

    PubMed Central

    2013-01-01

    Background Long-lasting insecticide-treated mosquito nets (LLINs) are a primary malaria prevention strategy in sub-Saharan Africa. However, emergence of insecticide resistance threatens the effectiveness of LLINs. Methods Cross-sectional surveys of LLINs were conducted in houses of seven and four villages in Gem and Bungoma Districts in western Kenya, respectively. Condition (number and area of holes in the nets), number and species of mosquitoes resting inside them, and insecticidal activity of nets were quantified. Mosquitoes collected inside nets were allowed to lay eggs and progeny tested for susceptibility to deltamethrin and permethrin, pyrethoids commonly deployed in LLINs in western Kenya. Results In Gem, 83.3% of nets were less than three years old and 32.4% had at least one hole of any size; while in Bungoma, 92% were less than three years old and 48% had at least one hole. No anopheline and five Culex spp. mosquitoes were found resting inside nets in Gem regardless of the number and size of holes, while 552 Anopheles gambiae s.l., five Anopheles funestus s.l. and 137 Culex spp. were in nets in Bungoma. The number of mosquitoes resting inside nets increased with hole areas >50 cm in Bungoma. In WHO resistance assays, f1 offspring of samples collected in nets in Bungoma were 94 and 65% resistant to deltamethrin and permethrin, respectively. Nets from Bungoma retained strong activity against a susceptible laboratory strain, but not against f1 offspring of field-collected An. gambiae s.s. All An. gambiae s.s. samples collected in nets were homozygous for the kdr genotype L1014S. Conclusions In areas with pyrethroid resistant vectors, LLINs with modest hole areas permit mosquito entry and feeding, providing little protection against the vectors. LLIN formulations develop large holes within three years of use, diminishing their presupposed lifetime effectiveness. PMID:24156715

  3. High levels of antimicrobial resistance among escherichia coli isolates from livestock farms and synanthropic rats and shrews in the Mekong Delta of Vietnam.

    PubMed

    Nhung, N T; Cuong, N V; Campbell, J; Hoa, N T; Bryant, J E; Truc, V N T; Kiet, B T; Jombart, T; Trung, N V; Hien, V B; Thwaites, G; Baker, S; Carrique-Mas, J

    2015-02-01

    In Mekong Delta farms (Vietnam), antimicrobials are extensively used, but limited data are available on levels of antimicrobial resistance (AMR) among Escherichia coli isolates. We performed a structured survey of AMR in E. coli isolates (n = 434) from 90 pig, chicken, and duck farms. The results were compared with AMR among E. coli isolates (n = 234) from 66 small wild animals (rats and shrews) trapped on farms and in forests and rice fields. The isolates were susceptibility tested against eight antimicrobials. E. coli isolates from farmed animals were resistant to a median of 4 (interquartile range [IQR], 3 to 6) antimicrobials versus 1 (IQR, 1 to 2) among wild mammal isolates (P < 0.001). The prevalences of AMR among farmed species isolates (versus wild animals) were as follows: tetracycline, 84.7% (versus 25.6%); ampicillin, 78.9% (versus 85.9%); trimethoprim-sulfamethoxazole, 52.1% (versus 18.8%); chloramphenicol, 39.9% (versus 22.5%); amoxicillin-clavulanic acid, 36.6% (versus 34.5%); and ciprofloxacin, 24.9% (versus 7.3%). The prevalence of multidrug resistance (MDR) (resistance against three or more antimicrobial classes) among pig isolates was 86.7% compared to 66.9 to 72.7% among poultry isolates. After adjusting for host species, MDR was ∼8 times greater among isolates from wild mammals trapped on farms than among those trapped in forests/rice fields (P < 0.001). Isolates were assigned to unique profiles representing their combinations of susceptibility results. Multivariable analysis of variance indicated that AMR profiles from wild mammals trapped on farms and those from domestic animals were more alike (R(2) range, 0.14 to 0.30) than E. coli isolates from domestic animals and mammals trapped in the wild (R(2) range, 0.25 to 0.45). The results strongly suggest that AMR on farms is a key driver of environmental AMR in the Mekong Delta.

  4. Cyt1Aa Protein of Bacillus thuringiensis Is Toxic to the Cottonwood Leaf Beetle, Chrysomela scripta, and Suppresses High Levels of Resistance to Cry3Aa

    PubMed Central

    Federici, Brian A.; Bauer, Leah S.

    1998-01-01

    The insecticidal activity of Bacillus thuringiensis is due primarily to Cry and Cyt proteins. Cry proteins are typically toxic to lepidopterous, coleopterous, or dipterous insects, whereas the known toxicity of Cyt proteins is limited to dipterans. We report here that a Cyt protein, Cyt1Aa, is also highly toxic to the cottonwood leaf beetle, Chrysomela scripta, with a median lethal concentration of 2.5 ng/mm2 of leaf surface for second-instar larvae. Additionally, we show that Cyt1Aa suppresses resistance to Cry3Aa greater than 5,000-fold in C. scripta, a level only partially overcome by Cry1Ba due to cross-resistance. Studies of the histopathology of C. scripta larvae treated with Cyt1Aa revealed disruption and sloughing of midgut epithelial cells, indicating that its mechanism of action against C. scripta is similar to that observed in mosquito and blackfly larvae. These novel properties suggest that Cyt proteins may have an even broader spectrum of activity against insects and, owing to their different mechanism of action in comparison to Cry proteins, might be useful in managing resistance to Cry3 and possibly other Cry toxins used in microbial insecticides and transgenic plants. PMID:9797292

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

    PubMed Central

    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. PMID:27294780

  6. High Levels of Antimicrobial Resistance among Escherichia coli Isolates from Livestock Farms and Synanthropic Rats and Shrews in the Mekong Delta of Vietnam

    PubMed Central

    Nhung, N. T.; Cuong, N. V.; Campbell, J.; Hoa, N. T.; Bryant, J. E.; Truc, V. N. T.; Kiet, B. T.; Jombart, T.; Trung, N. V.; Hien, V. B.; Thwaites, G.; Baker, S.

    2014-01-01

    In Mekong Delta farms (Vietnam), antimicrobials are extensively used, but limited data are available on levels of antimicrobial resistance (AMR) among Escherichia coli isolates. We performed a structured survey of AMR in E. coli isolates (n = 434) from 90 pig, chicken, and duck farms. The results were compared with AMR among E. coli isolates (n = 234) from 66 small wild animals (rats and shrews) trapped on farms and in forests and rice fields. The isolates were susceptibility tested against eight antimicrobials. E. coli isolates from farmed animals were resistant to a median of 4 (interquartile range [IQR], 3 to 6) antimicrobials versus 1 (IQR, 1 to 2) among wild mammal isolates (P < 0.001). The prevalences of AMR among farmed species isolates (versus wild animals) were as follows: tetracycline, 84.7% (versus 25.6%); ampicillin, 78.9% (versus 85.9%); trimethoprim-sulfamethoxazole, 52.1% (versus 18.8%); chloramphenicol, 39.9% (versus 22.5%); amoxicillin-clavulanic acid, 36.6% (versus 34.5%); and ciprofloxacin, 24.9% (versus 7.3%). The prevalence of multidrug resistance (MDR) (resistance against three or more antimicrobial classes) among pig isolates was 86.7% compared to 66.9 to 72.7% among poultry isolates. After adjusting for host species, MDR was ∼8 times greater among isolates from wild mammals trapped on farms than among those trapped in forests/rice fields (P < 0.001). Isolates were assigned to unique profiles representing their combinations of susceptibility results. Multivariable analysis of variance indicated that AMR profiles from wild mammals trapped on farms and those from domestic animals were more alike (R2 range, 0.14 to 0.30) than E. coli isolates from domestic animals and mammals trapped in the wild (R2 range, 0.25 to 0.45). The results strongly suggest that AMR on farms is a key driver of environmental AMR in the Mekong Delta. PMID:25398864

  7. A Novel Nitrobenzoate Microtubule Inhibitor that Overcomes Multidrug Resistance Exhibits Antitumor Activity.

    PubMed

    Zheng, Yan-Bo; Gong, Jian-Hua; Liu, Xiu-Jun; Wu, Shu-Ying; Li, Yi; Xu, Xian-Dong; Shang, Bo-Yang; Zhou, Jin-Ming; Zhu, Zhi-Ling; Si, Shu-Yi; Zhen, Yong-Su

    2016-01-01

    Multidrug resistance is a major limitation for microtubule-binding agents in cancer treatment. Here we report a novel microtubule inhibitor (2-morpholin-4-yl-5-nitro-benzoic acid 4-methylsulfanyl-benzyl ester, IMB5046), its cytotoxicity against multidrug-resistant cell lines and its antitumor efficacy in animal models. IMB5046 disrupted microtubule structures in cells and inhibited purified tubulin polymerization in vitro. It bound to the colchicine pocket of tubulin. IMB5046 displayed potent cytotoxicity against multiple tumor cell lines with an IC50 range of 0.037-0.426 μM. Notably, several multidrug-resistant cell lines which were resistant to colchicine, vincristine and paclitaxel remained sensitive to IMB5046. IMB5046 was not a P-glycoprotein substrate. IMB5046 blocked cell cycle at G2/M phase and induced cell apoptosis. Microarray assay indicated that the differentially expressed genes after IMB5046 treatment were highly related to immune system, cell death and cancer. In a mouse xenograft model IMB5046 inhibited the growth of human lung tumor xenograft by 83% at a well-tolerated dose. It is concluded that IMB5046 is a tubulin polymerization inhibitor with novel chemical structure and can overcome multidrug resistance. It is a promising lead compound for cancer chemotherapy, especially for treatment of multidrug-resistant tumors. PMID:27510727

  8. A Novel Nitrobenzoate Microtubule Inhibitor that Overcomes Multidrug Resistance Exhibits Antitumor Activity

    PubMed Central

    Zheng, Yan-Bo; Gong, Jian-Hua; Liu, Xiu-Jun; Wu, Shu-Ying; Li, Yi; Xu, Xian-Dong; Shang, Bo-Yang; Zhou, Jin-Ming; Zhu, Zhi-Ling; Si, Shu-Yi; Zhen, Yong-Su

    2016-01-01

    Multidrug resistance is a major limitation for microtubule-binding agents in cancer treatment. Here we report a novel microtubule inhibitor (2-morpholin-4-yl-5-nitro-benzoic acid 4-methylsulfanyl-benzyl ester, IMB5046), its cytotoxicity against multidrug-resistant cell lines and its antitumor efficacy in animal models. IMB5046 disrupted microtubule structures in cells and inhibited purified tubulin polymerization in vitro. It bound to the colchicine pocket of tubulin. IMB5046 displayed potent cytotoxicity against multiple tumor cell lines with an IC50 range of 0.037–0.426 μM. Notably, several multidrug-resistant cell lines which were resistant to colchicine, vincristine and paclitaxel remained sensitive to IMB5046. IMB5046 was not a P-glycoprotein substrate. IMB5046 blocked cell cycle at G2/M phase and induced cell apoptosis. Microarray assay indicated that the differentially expressed genes after IMB5046 treatment were highly related to immune system, cell death and cancer. In a mouse xenograft model IMB5046 inhibited the growth of human lung tumor xenograft by 83% at a well-tolerated dose. It is concluded that IMB5046 is a tubulin polymerization inhibitor with novel chemical structure and can overcome multidrug resistance. It is a promising lead compound for cancer chemotherapy, especially for treatment of multidrug-resistant tumors. PMID:27510727

  9. An Escherichia coli strain, PGB01, isolated from feral pigeon Faeces, thermally fit to survive in pigeon, shows high level resistance to trimethoprim.

    PubMed

    Kumar, Arvind; Tiwary, Bipransh Kumar; Kachhap, Sangita; Nanda, Ashis Kumar; Chakraborty, Ranadhir

    2015-01-01

    In this study, of the hundred Escherichia coli strains isolated from feral Pigeon faeces, eighty five strains were resistant to one or more antibiotics and fifteen sensitive to all the antibiotics tested. The only strain (among all antibiotic-resistant E. coli isolates) that possessed class 1 integron was PGB01. The dihydrofolate reductase gene of the said integron was cloned, sequenced and expressed in E. coli JM109. Since PGB01 was native to pigeon's gut, we have compared the growth of PGB01 at two different temperatures, 42°C (normal body temperature of pigeon) and 37°C (optimal growth temperature of E. coli; also the human body temperature), with E. coli K12. It was found that PGB01 grew better than the laboratory strain E. coli K12 at 37°C as well as at 42°C. In the thermal fitness assay, it was observed that the cells of PGB01 were better adapted to 42°C, resembling the average body temperature of pigeon. The strain PGB01 also sustained more microwave mediated thermal stress than E. coli K12 cells. The NMR spectra of the whole cells of PGB01 varied from E. coli K12 in several spectral peaks relating some metabolic adaptation to thermotolerance. On elevating the growth temperature from 37°C to 42°C, susceptibility to kanamycin (both strains were sensitive to it) of E. coli K12 was increased, but in case of PGB01 no change in susceptibility took place. We have also attempted to reveal the basis of trimethoprim resistance phenotype conferred by the dfrA7 gene homologue of PGB01. Molecular Dynamics (MD) simulation study of docked complexes, PGB01-DfrA7 and E. coli TMP-sensitive-Dfr with trimethoprim (TMP) showed loss of some of the hydrogen and hydrophobic interaction between TMP and mutated residues in PGB01-DfrA7-TMP complex compared to TMP-sensitive-Dfr-TMP complex. This loss of interaction entails decrease in affinity of TMP for PGB01-DfrA7 compared to TMP-sensitive-Dfr. PMID:25750990

  10. An Escherichia coli strain, PGB01, isolated from feral pigeon Faeces, thermally fit to survive in pigeon, shows high level resistance to trimethoprim.

    PubMed

    Kumar, Arvind; Tiwary, Bipransh Kumar; Kachhap, Sangita; Nanda, Ashis Kumar; Chakraborty, Ranadhir

    2015-01-01

    In this study, of the hundred Escherichia coli strains isolated from feral Pigeon faeces, eighty five strains were resistant to one or more antibiotics and fifteen sensitive to all the antibiotics tested. The only strain (among all antibiotic-resistant E. coli isolates) that possessed class 1 integron was PGB01. The dihydrofolate reductase gene of the said integron was cloned, sequenced and expressed in E. coli JM109. Since PGB01 was native to pigeon's gut, we have compared the growth of PGB01 at two different temperatures, 42°C (normal body temperature of pigeon) and 37°C (optimal growth temperature of E. coli; also the human body temperature), with E. coli K12. It was found that PGB01 grew better than the laboratory strain E. coli K12 at 37°C as well as at 42°C. In the thermal fitness assay, it was observed that the cells of PGB01 were better adapted to 42°C, resembling the average body temperature of pigeon. The strain PGB01 also sustained more microwave mediated thermal stress than E. coli K12 cells. The NMR spectra of the whole cells of PGB01 varied from E. coli K12 in several spectral peaks relating some metabolic adaptation to thermotolerance. On elevating the growth temperature from 37°C to 42°C, susceptibility to kanamycin (both strains were sensitive to it) of E. coli K12 was increased, but in case of PGB01 no change in susceptibility took place. We have also attempted to reveal the basis of trimethoprim resistance phenotype conferred by the dfrA7 gene homologue of PGB01. Molecular Dynamics (MD) simulation study of docked complexes, PGB01-DfrA7 and E. coli TMP-sensitive-Dfr with trimethoprim (TMP) showed loss of some of the hydrogen and hydrophobic interaction between TMP and mutated residues in PGB01-DfrA7-TMP complex compared to TMP-sensitive-Dfr-TMP complex. This loss of interaction entails decrease in affinity of TMP for PGB01-DfrA7 compared to TMP-sensitive-Dfr.

  11. All detectable high-molecular-mass penicillin-binding proteins are modified in a high-level beta-lactam-resistant clinical isolate of Streptococcus mitis.

    PubMed

    Amoroso, A; Demares, D; Mollerach, M; Gutkind, G; Coyette, J

    2001-07-01

    All detectable high-molecular-mass penicillin-binding proteins (HMM PBPs) are altered in a clinical isolate of Streptococcus mitis for which the beta-lactam MICs are increased from those previously reported in our region (cefotaxime MIC, 64 microg/ml). These proteins were hardly detected at concentrations that saturate all PBPs in clinical isolates and showed, after densitometric analysis, 50-fold-lower radiotracer binding. Resistance was related to mosaic structure in all HMM PBP-coding genes, where critical region replacement was complemented not only by substitutions already reported for the closely related Streptococcus pneumoniae but also by other specific replacements that are presumably close to the active-site serine. Mosaic structure was also presumed in a pbp1a-sensitive strain used for comparison, confirming that these structures do not unambiguously imply, by themselves, detectable critical changes in the kinetic properties of these proteins.

  12. All Detectable High-Molecular-Mass Penicillin-Binding Proteins Are Modified in a High-Level β-Lactam-Resistant Clinical Isolate of Streptococcus mitis

    PubMed Central

    Amoroso, Ana; Demares, Diego; Mollerach, Marta; Gutkind, Gabriel; Coyette, Jacques

    2001-01-01

    All detectable high-molecular-mass penicillin-binding proteins (HMM PBPs) are altered in a clinical isolate of Streptococcus mitis for which the β-lactam MICs are increased from those previously reported in our region (cefotaxime MIC, 64 μg/ml). These proteins were hardly detected at concentrations that saturate all PBPs in clinical isolates and showed, after densitometric analysis, 50-fold-lower radiotracer binding. Resistance was related to mosaic structure in all HMM PBP-coding genes, where critical region replacement was complemented not only by substitutions already reported for the closely related Streptococcus pneumoniae but also by other specific replacements that are presumably close to the active-site serine. Mosaic structure was also presumed in a pbp1a-sensitive strain used for comparison, confirming that these structures do not unambiguously imply, by themselves, detectable critical changes in the kinetic properties of these proteins. PMID:11408226

  13. An in vivo mutation from leucine to tryptophan at position 210 in human immunodeficiency virus type 1 reverse transcriptase contributes to high-level resistance to 3'-azido-3'-deoxythymidine.

    PubMed Central

    Hooker, D J; Tachedjian, G; Solomon, A E; Gurusinghe, A D; Land, S; Birch, C; Anderson, J L; Roy, B M; Arnold, E; Deacon, N J

    1996-01-01

    Sequencing of the reverse transcriptase (RT) region of 26 human immunodeficiency virus type 1 (HIV-1) isolates from eight patients treated with 3'-azido-3'-deoxythymidine (AZT) revealed a mutation at codon 210 from TTG (leucine) to TGG (tryptophan) exclusively in association with resistance to AZT. The mutation Trp-210 was observed in 15 of the 20 isolates phenotypically resistant to AZT, being more commonly observed than resistance-associated mutations at codons 67, 70, and 219. Trp-210 was never observed before the emergence of resistance-associated mutations Leu-41 and Tyr-215, and in a sequential series of five isolates from one patient the order of emergence of mutations was found to be Tyr-215, Leu-41, and then Trp-210. Trp-210 was also found in association with the Leu-41, Asn-67, Arg-70, and Tyr-215 resistance genotype. To define the role of Trp-210 in AZT resistance, molecular HIV-1 clones were constructed with various combinations of RT mutations at codons 41, 67, 70, 210, and 215 and tested for susceptibility to AZT. In clones with polymerase genes derived either from HXB2-D or clinical isolates, Trp-210 alone did not increase AZT resistance, whereas in conjunction with Leu-41 and Tyr-215, Trp-210 contributed to high-level resistance (50% inhibitory concentration of >1 microM). In HXB2-D, Trp-210 with Tyr-215 generated a virus with resistance comparable to one with Leu-41, Tyr-215, and Trp-210. Inserting Trp-210 into the genetic context of mutations at codons 41, 67, 70, and 215 further enhanced resistance from a 50% inhibitory concentration of 1.44 microM to 8.41 microM. Molecular modeling of the tertiary structure of HIV-1 RT revealed that the distance between the side chains of Trp-210 (in helix alphaF) and Tyr-215 (in strand beta11a) approximated 4 A (1 A = 0.1 nm), sufficiently close to result in significant energetic interaction between these two aromatic side chains. In conclusion, Trp-210 contributes significantly to phenotypic AZT resistance of

  14. Second generation peanut genotypes resistant to thrips-transmitted tomato spotted wilt virus exhibit tolerance rather than true resistance and differentially affect thrips fitness.

    PubMed

    Shrestha, Anita; Srinivasan, Rajagopalbabu; Sundaraj, Sivamani; Culbreath, Albert K; Riley, David G

    2013-04-01

    Spotted wilt disease caused by Tomato spotted wilt virus (TSWV) (family Bunyaviridae; genus Tospovirus) is a major constraint to peanut (Arachis hypogaea L.) production in the southeastern United States. Reducing yield losses to TSWV has heavily relied on planting genotypes that reduce the incidence of spotted wilt disease. However, mechanisms conferring resistance to TSWV have not been identified in these genotypes. Furthermore, no information is available on how these genotypes influence thrips fitness. In this study, we investigated the effects of newly released peanut genotypes (Georganic, GA-06G, Tifguard, and NC94022) with field resistance to TSWV and a susceptible genotype (Georgia Green) on tobacco thrips, Frankliniella fusca (Hinds), fitness, and TSWV incidence. Thrips-mediated transmission resulted in TSWV infection in both TSWV-resistant and susceptible genotypes and they exhibited typical TSWV symptoms. However, some resistant genotypes had reduced viral loads (fewer TSWV N-gene copies) than the susceptible genotype. F. fusca larvae acquired TSWV from resistant and susceptible genotypes indicating that resistant genotypes also can serve as inoculum sources. Unlike resistant genotypes in other crops that produce local lesions (hypersensitive reaction) upon TSWV infection, widespread symptom development was noticed in peanut genotypes. Results indicated that the observed field resistance in peanut genotypes could be because of tolerance. Further, fitness studies revealed some, but not substantial, differences in thrips adult emergence rates and developmental time between resistant and susceptible genotypes. Thrips head capsule length and width were not different when reared on different genotypes.

  15. Kinetics of high-Level of ß-glucosidase production by a 2-deoxyglucose-resistant mutant of Humicola lanuginosa in submerged fermentation

    PubMed Central

    Bokhari, Syed Ali Imran; Latif, Farooq; Rajoka, Muhammad Ibrahim

    2008-01-01

    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 organism and M7 was studied using batch process at eight different temperatures in shake-flask studies. The best performance was found at 45°C and 20 g L−1 corncobs in 64 h. Both growth and product formation (17.93 U mL−1) were remarkably high at 45°C 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. PMID:24031297

  16. Good News? Codling Moth Exhibits Negative Cross Resistance Between Guthion and Rimon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The responses of adult codling moth from several field-collected populations and a laboratory-reared colony to residues of Rimon were evaluated in plastic cup adult bioassays. Both fecundity and successful egg hatch varied among populations. Populations of codling moth that exhibited the highest LC5...

  17. Physical Cross-Linking Starch-Based Zwitterionic Hydrogel Exhibiting Excellent Biocompatibility, Protein Resistance, and Biodegradability.

    PubMed

    Ye, Lei; Zhang, Yabin; Wang, Qiangsong; Zhou, Xin; Yang, Boguang; Ji, Feng; Dong, Dianyu; Gao, Lina; Cui, Yuanlu; Yao, Fanglian

    2016-06-22

    In this work, a novel starch-based zwitterionic copolymer, starch-graft-poly(sulfobetaine methacrylate) (ST-g-PSBMA), was synthesized via Atom Transfer Radical Polymerization. Starch, which formed the main chain, can be degraded completely in vivo, and the pendent segments of PSBMA endowed the copolymer with excellent protein resistance properties. This ST-g-PSBMA copolymer could self-assemble into a physical hydrogel in normal saline, and studies of the formation mechanism indicated that the generation of the physical hydrogel was driven by electrostatic interactions between PSBMA segments. The obtained hydrogels were subjected to detailed analysis by scanning electron microscopy, swelling ratio, protein resistance, and rheology tests. Toxicity and hemolysis analysis demonstrated that the ST-g-PSBMA hydrogels possess excellent biocompatibility and hemocompatibility. Moreover, the cytokine secretion assays (IL-6, TNF-α, and NO) confirmed that ST-g-PSBMA hydrogels had low potential to trigger the activation of macrophages and were suitable for in vivo biomedical applications. On the basis of these in vitro results, the ST-g-PSBMA hydrogels were implanted in SD rats. The tissue responses to hydrogel implantation and the hydrogel degradation in vivo were determined by histological analysis (Hematoxylin and eosin, Van Gieson, and Masson's Trichrome stains). The results presented in this study demonstrate that the physical cross-linking, starch-based zwitterionic hydrogels possess excellent protein resistance, low macrophage-activation properties, and good biocompatibility, and they are a promising candidate for an in vivo biomedical application platform.

  18. Multi-transgenic minipig models exhibiting potential for hepatic insulin resistance and pancreatic apoptosis

    PubMed Central

    KONG, SIYUAN; RUAN, JINXUE; XIN, LEILEI; FAN, JUNHUA; XIA, JIHAN; LIU, ZHIGUO; MU, YULIAN; YANG, SHULIN; LI, KUI

    2016-01-01

    There are currently no multi-transgenic minipig models of diabetes for the regulation of multiple genes involved in its pathogenesis. The foot and mouth disease virus 2A (F2A)-mediated polycistronic system possesses several advantages, and the present study developed a novel multi-transgenic minipig model associated with diabetes using this system. The tissue-specific polycistronic system used in the present study consisted of two expression cassettes, separated by an insulator: (i) 11-β-hydroxysteroid dehydrogenase 1 (11β-HSD1), driven by the porcine liver-specific apolipoprotein E promoter; (ii) human islet amyloid polypeptide (hIAPP) and C/EBP homologous protein (CHOP), linked to the furin digested site and F-2A, driven by the porcine pancreas-specific insulin promoter. In the present study, porcine fetal fibroblasts were transfected with this vector. Following somatic cell nuclear transfer using 10 cell clones and the transplantation of 1,459 embryos in total, three Landrace x Yorkshire surrogates became pregnant and delivered three Wuzhishan piglets. Genomic polymerase chain reaction (PCR) demonstrated that the piglets were multi-transgenic. Reverse transcription-quantitative PCR confirmed that 11β-HSD1 transcription was upregulated in the targeted liver. Similarly, hIAPP and CHOP were expressed at high levels, compared with the control (P<0.05 and P<0.01) in the pancreas, consistent with the western blotting and immunohistochemistry results. The primary results also showed that overexpression of 11β-HSD1 in the liver increased the liver fat lipid parameters; and the levels of hIAPP and CHOP in the pancreatic islet cells, leading to delayed β-cell development and apoptosis. This novel tissue-specific polycistronic system offers a promising starting point for efficiently mimicking multigenic metabolic disease. PMID:26648014

  19. Acrylic coatings exhibiting improved hardness, solvent resistance and glossiness by using silica nano-composites

    NASA Astrophysics Data System (ADS)

    Dashtizadeh, Ahmad; Abdouss, Majid; Mahdavi, Hossein; Khorassani, Manuchehr

    2011-01-01

    To prepare nano-composite emulsion acrylic resins with improved surface hardness and solvent resistance, nano-silica particles were treated with surfactants. The monomers of methyl methacrylate/butylacrylate were co-polymerized on the surface of dispersed silica particles. Several emulsions with different silica contents and copolymer mole fractions were prepared. Finally the emulsions were modified to water-based acrylic coatings and improved properties such as surface hardness, solvent resistance and glossiness were determined. The study of coatings was directed to find the improved resin by optimum surface properties. Size distribution and morphology of latexes were characterized by Fourier transform infrared spectroscopy, dynamic light scattering, transmission electron microscopy and scanning electron microscopy. The glass transition temperature of nano-composites was measured and discussed its relation with silica contents, monomer mole fractions and improved properties of coatings. The optimum pendulum hardness of coatings was on 0.46 methyl methacrylate mole fraction and 120 g silica content. An increase in pendulum hardness of nano-composites with the addition of modified silica was observed. DLS and TEM studies indicate that silica particles were dispersed homogenously through the polymer matrix.

  20. Bacillus thermoamylovorans Spores with Very-High-Level Heat Resistance Germinate Poorly in Rich Medium despite the Presence of ger Clusters but Efficiently upon Exposure to Calcium-Dipicolinic Acid.

    PubMed

    Berendsen, Erwin M; Krawczyk, Antonina O; Klaus, Verena; de Jong, Anne; Boekhorst, Jos; Eijlander, Robyn T; Kuipers, Oscar P; Wells-Bennik, Marjon H J

    2015-11-01

    High-level heat resistance of spores of Bacillus thermoamylovorans poses challenges to the food industry, as industrial sterilization processes may not inactivate such spores, resulting in food spoilage upon germination and outgrowth. In this study, the germination and heat resistance properties of spores of four food-spoiling isolates were determined. Flow cytometry counts of spores were much higher than their counts on rich medium (maximum, 5%). Microscopic analysis revealed inefficient nutrient-induced germination of spores of all four isolates despite the presence of most known germination-related genes, including two operons encoding nutrient germinant receptors (GRs), in their genomes. In contrast, exposure to nonnutrient germinant calcium-dipicolinic acid (Ca-DPA) resulted in efficient (50 to 98%) spore germination. All four strains harbored cwlJ and gerQ genes, which are known to be essential for Ca-DPA-induced germination in Bacillus subtilis. When determining spore survival upon heating, low viable counts can be due to spore inactivation and an inability to germinate. To dissect these two phenomena, the recoveries of spores upon heat treatment were determined on plates with and without preexposure to Ca-DPA. The high-level heat resistance of spores as observed in this study (D120°C, 1.9 ± 0.2 and 1.3 ± 0.1 min; z value, 12.2 ± 1.8°C) is in line with survival of sterilization processes in the food industry. The recovery of B. thermoamylovorans spores can be improved via nonnutrient germination, thereby avoiding gross underestimation of their levels in food ingredients.

  1. Bacillus thermoamylovorans Spores with Very-High-Level Heat Resistance Germinate Poorly in Rich Medium despite the Presence of ger Clusters but Efficiently upon Exposure to Calcium-Dipicolinic Acid.

    PubMed

    Berendsen, Erwin M; Krawczyk, Antonina O; Klaus, Verena; de Jong, Anne; Boekhorst, Jos; Eijlander, Robyn T; Kuipers, Oscar P; Wells-Bennik, Marjon H J

    2015-11-01

    High-level heat resistance of spores of Bacillus thermoamylovorans poses challenges to the food industry, as industrial sterilization processes may not inactivate such spores, resulting in food spoilage upon germination and outgrowth. In this study, the germination and heat resistance properties of spores of four food-spoiling isolates were determined. Flow cytometry counts of spores were much higher than their counts on rich medium (maximum, 5%). Microscopic analysis revealed inefficient nutrient-induced germination of spores of all four isolates despite the presence of most known germination-related genes, including two operons encoding nutrient germinant receptors (GRs), in their genomes. In contrast, exposure to nonnutrient germinant calcium-dipicolinic acid (Ca-DPA) resulted in efficient (50 to 98%) spore germination. All four strains harbored cwlJ and gerQ genes, which are known to be essential for Ca-DPA-induced germination in Bacillus subtilis. When determining spore survival upon heating, low viable counts can be due to spore inactivation and an inability to germinate. To dissect these two phenomena, the recoveries of spores upon heat treatment were determined on plates with and without preexposure to Ca-DPA. The high-level heat resistance of spores as observed in this study (D120°C, 1.9 ± 0.2 and 1.3 ± 0.1 min; z value, 12.2 ± 1.8°C) is in line with survival of sterilization processes in the food industry. The recovery of B. thermoamylovorans spores can be improved via nonnutrient germination, thereby avoiding gross underestimation of their levels in food ingredients. PMID:26341201

  2. Bacillus thermoamylovorans Spores with Very-High-Level Heat Resistance Germinate Poorly in Rich Medium despite the Presence of ger Clusters but Efficiently upon Exposure to Calcium-Dipicolinic Acid

    PubMed Central

    Berendsen, Erwin M.; Krawczyk, Antonina O.; Klaus, Verena; de Jong, Anne; Boekhorst, Jos; Eijlander, Robyn T.

    2015-01-01

    High-level heat resistance of spores of Bacillus thermoamylovorans poses challenges to the food industry, as industrial sterilization processes may not inactivate such spores, resulting in food spoilage upon germination and outgrowth. In this study, the germination and heat resistance properties of spores of four food-spoiling isolates were determined. Flow cytometry counts of spores were much higher than their counts on rich medium (maximum, 5%). Microscopic analysis revealed inefficient nutrient-induced germination of spores of all four isolates despite the presence of most known germination-related genes, including two operons encoding nutrient germinant receptors (GRs), in their genomes. In contrast, exposure to nonnutrient germinant calcium-dipicolinic acid (Ca-DPA) resulted in efficient (50 to 98%) spore germination. All four strains harbored cwlJ and gerQ genes, which are known to be essential for Ca-DPA-induced germination in Bacillus subtilis. When determining spore survival upon heating, low viable counts can be due to spore inactivation and an inability to germinate. To dissect these two phenomena, the recoveries of spores upon heat treatment were determined on plates with and without preexposure to Ca-DPA. The high-level heat resistance of spores as observed in this study (D120°C, 1.9 ± 0.2 and 1.3 ± 0.1 min; z value, 12.2 ± 1.8°C) is in line with survival of sterilization processes in the food industry. The recovery of B. thermoamylovorans spores can be improved via nonnutrient germination, thereby avoiding gross underestimation of their levels in food ingredients. PMID:26341201

  3. Mungbean plants expressing BjNPR1 exhibit enhanced resistance against the seedling rot pathogen, Rhizoctonia solani.

    PubMed

    Vijayan, S; Kirti, P B

    2012-02-01

    Mungbean, Vigna radiata (L.) Wilczek is an important pulse crop that is widely cultivated in semi- arid tropics. The crop is attacked by various soil-borne pathogens like Rhizoctonia solani, which causes dry rot disease and seriously affects its productivity. Earlier we characterized the non-expressor of pathogenesis related gene-1(BjNPR1) of mustard, Brassica juncea, the counterpart of AtNPR1 of Arabidopsis thaliana. Here, we transformed mungbean with BjNPR1 via Agrobacterium tumefaciens. Because of the recalcitrant nature of mungbean, the effect of some factors like Agrobacterium tumefaciens strains (GV2260 and LBA4404), pH, L: -cysteine and tobacco leaf extract was tested in transformation. The transgenic status of 15 plants was confirmed by PCR using primers for nptII. The independent integration of T-DNA in transgenic plants was analyzed by Southern hybridization with an nptII probe and the expression of BjNPR1 was confirmed by RT-PCR. Some of the T(0) plants were selected for detached leaf anti-fungal bioassay using the fungus Rhizoctonia solani, which showed moderate to high level of resistance depending on the level of expression of BjNPR1. The seedling bioassay of transgenic T(2) plants indicated resistance against dry rot disease caused by R. solani.

  4. D-β-aspartyl residue exhibiting uncommon high resistance to spontaneous peptide bond cleavage

    PubMed Central

    Aki, Kenzo; Okamura, Emiko

    2016-01-01

    Although L-amino acids were selected as main constituents of peptides and proteins during chemical evolution, D-aspartyl (Asp) residue is found in a variety of living tissues. In particular, D-β-Asp is thought to be stable than any other Asp isomers, and this could be a reason for gradual accumulation in abnormal proteins and peptides to modify their structures and functions. It is predicted that D-β-Asp shows high resistance to biomolecular reactions. For instance, less reactivity of D-β-Asp is expected to bond cleavage, although such information has not been provided yet. In this work, the spontaneous peptide bond cleavage was compared between Asp isomers, by applying real-time solution-state NMR to eye lens αΑ-crystallin 51–60 fragment, S51LFRTVLD58SG60 and αΒ-crystallin 61–67 analog, F61D62TGLSG67 consisting of L-α- and D-β-Asp 58 and 62, respectively. Kinetic analysis showed how tough the uncommon D-β-Asp residue was against the peptide bond cleavage as compared to natural L-α-Asp. Differences in pKa and conformation between L-α- and D-β-Asp side chains were plausible factors to determine reactivity of Asp isomers. The present study, for the first time, provides a rationale to explain less reactivity of D-β-Asp to allow abnormal accumulation. PMID:26876027

  5. D-β-aspartyl residue exhibiting uncommon high resistance to spontaneous peptide bond cleavage

    NASA Astrophysics Data System (ADS)

    Aki, Kenzo; Okamura, Emiko

    2016-02-01

    Although L-amino acids were selected as main constituents of peptides and proteins during chemical evolution, D-aspartyl (Asp) residue is found in a variety of living tissues. In particular, D-β-Asp is thought to be stable than any other Asp isomers, and this could be a reason for gradual accumulation in abnormal proteins and peptides to modify their structures and functions. It is predicted that D-β-Asp shows high resistance to biomolecular reactions. For instance, less reactivity of D-β-Asp is expected to bond cleavage, although such information has not been provided yet. In this work, the spontaneous peptide bond cleavage was compared between Asp isomers, by applying real-time solution-state NMR to eye lens αΑ-crystallin 51-60 fragment, S51LFRTVLD58SG60 and αΒ-crystallin 61-67 analog, F61D62TGLSG67 consisting of L-α- and D-β-Asp 58 and 62, respectively. Kinetic analysis showed how tough the uncommon D-β-Asp residue was against the peptide bond cleavage as compared to natural L-α-Asp. Differences in pKa and conformation between L-α- and D-β-Asp side chains were plausible factors to determine reactivity of Asp isomers. The present study, for the first time, provides a rationale to explain less reactivity of D-β-Asp to allow abnormal accumulation.

  6. Blastocystis Isolate B Exhibits Multiple Modes of Resistance against Antimicrobial Peptide LL-37.

    PubMed

    Yason, John Anthony; Ajjampur, Sitara Swarna Rao; Tan, Kevin Shyong Wei

    2016-08-01

    Blastocystis is one of the most common eukaryotic organisms found in humans and many types of animals. Several reports have identified its role in gastrointestinal disorders, although its pathogenicity is yet to be clarified. Blastocystis is transmitted via the fecal-to-oral route and colonizes the large intestines. Epithelial cells lining the intestine secrete antimicrobial peptides (AMPs), including beta-defensins and cathelicidin, as a response to infection. This study explores the effects of host colonic antimicrobial peptides, particularly LL-37, a fragment of cathelicidin, on different Blastocystis subtypes. Blastocystis is composed of several subtypes that have genetic, metabolic, and biological differences. These subtypes also have various outcomes in terms of drug treatment and immune response. In this study, Blastocystis isolates from three different subtypes were found to induce intestinal epithelial cells to secrete LL-37. We also show that among the antimicrobial peptides tested, only LL-37 has broad activity on all the subtypes. LL-37 causes membrane disruption and causes Blastocystis to change shape. Blastocystis subtype 7 (ST7), however, showed relative resistance to LL-37. An isolate, ST7 isolate B (ST7-B), from this subtype releases proteases that can degrade the peptide. It also makes the environment acidic, which causes attenuation of LL-37 activity. The Blastocystis ST7-B isolate was also observed to have a thicker surface coat, which may protect the parasite from direct killing by LL-37. This study determined the effects of LL-37 on different Blastocystis isolates and indicates that AMPs have significant roles in Blastocystis infections. PMID:27217421

  7. Trichosporon inkin biofilms produce extracellular proteases and exhibit resistance to antifungals.

    PubMed

    de Aguiar Cordeiro, Rossana; Serpa, Rosana; Flávia Uchoa Alexandre, Camila; de Farias Marques, Francisca Jakelyne; Vladia Silva de Melo, Charlline; da Silva Franco, Jônatas; José de Jesus Evangelista, Antonio; Pires de Camargo, Zoilo; Samia Nogueira Brilhante, Raimunda; Fabio Gadelha Rocha, Marcos; Luciano Bezerra Moreira, José; de Jesus Pinheiro Gomes Bandeira, Tereza; Júlio Costa Sidrim, José

    2015-11-01

    The aim of this study was to determine experimental conditions for in vitro biofilm formation of clinical isolates of Trichosporon inkin, an important opportunistic pathogen in immunocompromised patients. Biofilms were formed in microtitre plates in three different media (RPMI, Sabouraud and CLED), with inocula of 104, 105 or 106 cells ml- 1, at pH 5.5 and 7.0, and at 35 and 28 °C, under static and shaking conditions for 72 h. Growth kinetics of biofilms were evaluated at 6, 24, 48 and 72 h. Biofilm milieu analysis were assessed by counting viable cells and quantification of nucleic acids released into biofilm supernatants. Biofilms were also analysed for proteolytic activity and antifungal resistance against amphotericin B, caspofungin, fluconazole, itraconazole and voriconazole. Finally, ultrastructural characterization of biofilms formed in microtitre plates and catheter disks was performed by scanning electron microscopy. Greater biofilm formation was observed with a starter inoculum of 106 cells ml- 1, at pH 7.0 at 35 °C and 80 r.p.m., in both RPMI and Sabouraud media. Growth kinetics showed an increase in both viable cells and biomass with increasing incubation time, with maximum production at 48 h. Biofilms were able to disperse viable cells and nucleic acids into the supernatant throughout the developmental cycle. T. inkin biofilms produced more protease than planktonic cells and showed high tolerance to amphotericin B, caspofungin and azole derivatives. Mature biofilms were formed by different morphotypes, such as blastoconidia, arthroconidia and hyphae, in a strain-specific manner. The present article details the multicellular lifestyle of T. inkin and provides perspectives for further research. PMID:26310576

  8. Trichosporon inkin biofilms produce extracellular proteases and exhibit resistance to antifungals.

    PubMed

    de Aguiar Cordeiro, Rossana; Serpa, Rosana; Flávia Uchoa Alexandre, Camila; de Farias Marques, Francisca Jakelyne; Vladia Silva de Melo, Charlline; da Silva Franco, Jônatas; José de Jesus Evangelista, Antonio; Pires de Camargo, Zoilo; Samia Nogueira Brilhante, Raimunda; Fabio Gadelha Rocha, Marcos; Luciano Bezerra Moreira, José; de Jesus Pinheiro Gomes Bandeira, Tereza; Júlio Costa Sidrim, José

    2015-11-01

    The aim of this study was to determine experimental conditions for in vitro biofilm formation of clinical isolates of Trichosporon inkin, an important opportunistic pathogen in immunocompromised patients. Biofilms were formed in microtitre plates in three different media (RPMI, Sabouraud and CLED), with inocula of 104, 105 or 106 cells ml- 1, at pH 5.5 and 7.0, and at 35 and 28 °C, under static and shaking conditions for 72 h. Growth kinetics of biofilms were evaluated at 6, 24, 48 and 72 h. Biofilm milieu analysis were assessed by counting viable cells and quantification of nucleic acids released into biofilm supernatants. Biofilms were also analysed for proteolytic activity and antifungal resistance against amphotericin B, caspofungin, fluconazole, itraconazole and voriconazole. Finally, ultrastructural characterization of biofilms formed in microtitre plates and catheter disks was performed by scanning electron microscopy. Greater biofilm formation was observed with a starter inoculum of 106 cells ml- 1, at pH 7.0 at 35 °C and 80 r.p.m., in both RPMI and Sabouraud media. Growth kinetics showed an increase in both viable cells and biomass with increasing incubation time, with maximum production at 48 h. Biofilms were able to disperse viable cells and nucleic acids into the supernatant throughout the developmental cycle. T. inkin biofilms produced more protease than planktonic cells and showed high tolerance to amphotericin B, caspofungin and azole derivatives. Mature biofilms were formed by different morphotypes, such as blastoconidia, arthroconidia and hyphae, in a strain-specific manner. The present article details the multicellular lifestyle of T. inkin and provides perspectives for further research.

  9. Fabrication and Characterization of a Micromachined Swirl-Shaped Ionic Polymer Metal Composite Actuator with Electrodes Exhibiting Asymmetric Resistance

    PubMed Central

    Feng, Guo-Hua; Liu, Kim-Min

    2014-01-01

    This paper presents a swirl-shaped microfeatured ionic polymer-metal composite (IPMC) actuator. A novel micromachining process was developed to fabricate an array of IPMC actuators on a glass substrate and to ensure that no shortcircuits occur between the electrodes of the actuator. We demonstrated a microfluidic scheme in which surface tension was used to construct swirl-shaped planar IPMC devices of microfeature size and investigated the flow velocity of Nafion solutions, which formed the backbone polymer of the actuator, within the microchannel. The unique fabrication process yielded top and bottom electrodes that exhibited asymmetric surface resistance. A tool for measuring surface resistance was developed and used to characterize the resistances of the electrodes for the fabricated IPMC device. The actuator, which featured asymmetric electrode resistance, caused a nonzero-bias current when the device was driven using a zero-bias square wave, and we propose a circuit model to describe this phenomenon. Moreover, we discovered and characterized a bending and rotating motion when the IPMC actuator was driven using a square wave. We observed a strain rate of 14.6% and a displacement of 700 μm in the direction perpendicular to the electrode surfaces during 4.5-V actuation. PMID:24824370

  10. Field Trial and Molecular Characterization of RNAi-Transgenic Tomato Plants That Exhibit Resistance to Tomato Yellow Leaf Curl Geminivirus.

    PubMed

    Fuentes, Alejandro; Carlos, Natacha; Ruiz, Yoslaine; Callard, Danay; Sánchez, Yadira; Ochagavía, María Elena; Seguin, Jonathan; Malpica-López, Nachelli; Hohn, Thomas; Lecca, Maria Rita; Pérez, Rosabel; Doreste, Vivian; Rehrauer, Hubert; Farinelli, Laurent; Pujol, Merardo; Pooggin, Mikhail M

    2016-03-01

    RNA interference (RNAi) is a widely used approach to generate virus-resistant transgenic crops. However, issues of agricultural importance like the long-term durability of RNAi-mediated resistance under field conditions and the potential side effects provoked in the plant by the stable RNAi expression remain poorly investigated. Here, we performed field trials and molecular characterization studies of two homozygous transgenic tomato lines, with different selection markers, expressing an intron-hairpin RNA cognate to the Tomato yellow leaf curl virus (TYLCV) C1 gene. The tested F6 and F4 progenies of the respective kanamycin- and basta-resistant plants exhibited unchanged field resistance to TYLCV and stably expressed the transgene-derived short interfering RNA (siRNAs) to represent 6 to 8% of the total plant small RNAs. This value outnumbered the average percentage of viral siRNAs in the nontransformed plants exposed to TYLCV-infested whiteflies. As a result of the RNAi transgene expression, a common set of up- and downregulated genes was revealed in the transcriptome profile of the plants selected from either of the two transgenic events. A previously unidentified geminivirus causing no symptoms of viral disease was detected in some of the transgenic plants. The novel virus acquired V1 and V2 genes from TYLCV and C1, C2, C3, and C4 genes from a distantly related geminivirus and, thereby, it could evade the repressive sequence-specific action of transgene-derived siRNAs. Our findings shed light on the mechanisms of siRNA-directed antiviral silencing in transgenic plants and highlight the applicability limitations of this technology as it may alter the transcriptional pattern of nontarget genes.

  11. Field Trial and Molecular Characterization of RNAi-Transgenic Tomato Plants That Exhibit Resistance to Tomato Yellow Leaf Curl Geminivirus.

    PubMed

    Fuentes, Alejandro; Carlos, Natacha; Ruiz, Yoslaine; Callard, Danay; Sánchez, Yadira; Ochagavía, María Elena; Seguin, Jonathan; Malpica-López, Nachelli; Hohn, Thomas; Lecca, Maria Rita; Pérez, Rosabel; Doreste, Vivian; Rehrauer, Hubert; Farinelli, Laurent; Pujol, Merardo; Pooggin, Mikhail M

    2016-03-01

    RNA interference (RNAi) is a widely used approach to generate virus-resistant transgenic crops. However, issues of agricultural importance like the long-term durability of RNAi-mediated resistance under field conditions and the potential side effects provoked in the plant by the stable RNAi expression remain poorly investigated. Here, we performed field trials and molecular characterization studies of two homozygous transgenic tomato lines, with different selection markers, expressing an intron-hairpin RNA cognate to the Tomato yellow leaf curl virus (TYLCV) C1 gene. The tested F6 and F4 progenies of the respective kanamycin- and basta-resistant plants exhibited unchanged field resistance to TYLCV and stably expressed the transgene-derived short interfering RNA (siRNAs) to represent 6 to 8% of the total plant small RNAs. This value outnumbered the average percentage of viral siRNAs in the nontransformed plants exposed to TYLCV-infested whiteflies. As a result of the RNAi transgene expression, a common set of up- and downregulated genes was revealed in the transcriptome profile of the plants selected from either of the two transgenic events. A previously unidentified geminivirus causing no symptoms of viral disease was detected in some of the transgenic plants. The novel virus acquired V1 and V2 genes from TYLCV and C1, C2, C3, and C4 genes from a distantly related geminivirus and, thereby, it could evade the repressive sequence-specific action of transgene-derived siRNAs. Our findings shed light on the mechanisms of siRNA-directed antiviral silencing in transgenic plants and highlight the applicability limitations of this technology as it may alter the transcriptional pattern of nontarget genes. PMID:26713353

  12. CLIC5 mutant mice are resistant to diet-induced obesity and exhibit gastric hemorrhaging and increased susceptibility to torpor

    PubMed Central

    Bradford, Emily M.; Miller, Marian L.; Prasad, Vikram; Nieman, Michelle L.; Gawenis, Lara R.; Berryman, Mark; Lorenz, John N.; Tso, Patrick

    2010-01-01

    Chloride intracellular channel 5 (CLIC5) and other CLIC isoforms have been implicated in a number of biological processes, but their specific functions are poorly understood. The association of CLIC5 with ezrin and the actin cytoskeleton led us to test its possible involvement in gastric acid secretion. Clic5 mutant mice exhibited only a minor reduction in acid secretion, Clic5 mRNA was expressed at only low levels in stomach, and Clic5 mutant parietal cells were ultrastructurally normal, negating the hypothesis that CLIC5 plays a major role in acid secretion. However, the mutants exhibited gastric hemorrhaging in response to fasting, reduced monocytes and granulocytes suggestive of immune dysfunction, behavioral and social disorders suggestive of neurological dysfunction, and evidence of a previously unidentified metabolic defect. Wild-type and mutant mice were maintained on normal and high-fat diets; plasma levels of various hormones, glucose, and lipids were determined; and body composition was studied by quantitative magnetic resonance imaging. Clic5 mutants were lean, hyperphagic, and highly resistant to diet-induced obesity. Plasma insulin and glucose levels were reduced, and leptin levels were very low; however, plasma triglycerides, cholesterol, phospholipids, and fatty acids were normal. Indirect calorimetry revealed increased peripheral metabolism and greater reliance on carbohydrate metabolism. Because Clic5 mutants were unable to maintain energy reserves, they also exhibited increased susceptibility to fasting-induced torpor, as indicated by telemetric measurements showing episodes of reduced body temperature and heart rate. These data reveal a requirement for CLIC5 in the maintenance of normal systemic energy metabolism. PMID:20357015

  13. High-Level Radioactive Waste.

    ERIC Educational Resources Information Center

    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…

  14. High levels of stearic acid, palmitoleic acid, and dihomo-γ-linolenic acid and low levels of linoleic acid in serum cholesterol ester are associated with high insulin resistance.

    PubMed

    Kurotani, Kayo; Sato, Masao; Ejima, Yuko; Nanri, Akiko; Yi, Siyan; Pham, Ngoc Minh; Akter, Shamima; Poudel-Tandukar, Kalpana; Kimura, Yasumi; Imaizumi, Katsumi; Mizoue, Tetsuya

    2012-09-01

    The association of fatty acid composition with insulin resistance and type 2 diabetes has been reported in Western populations, but there is limited evidence of this association among the Japanese, whose populace consume large amounts of fish. To test the hypothesis that high palmitic, palmitoleic, and dihomo-γ-linolenic acids and low levels of linoleic and n-3 fatty acids are associated with higher insulin resistance among the Japanese, the authors investigated the relationship between serum fatty acid composition and serum C-peptide concentrations in 437 Japanese employees aged 21 to 67 years who participated in a workplace health examination. Serum cholesterol ester and phospholipid fatty acid compositions were measured by gas-liquid chromatography. Desaturase activity was estimated by fatty acid product-to-precursor ratios. A multiple regression was used to assess the association between fatty acid and C-peptide concentrations. C-peptide concentrations were associated inversely with linoleic acid levels in cholesterol ester and phospholipid (P for trend = .01 and .02, respectively) and positively with stearic and palmitoleic acids in cholesterol ester (P for trend =.02 and .006, respectively) and dihomo-γ-linolenic acid in cholesterol ester and phospholipid (P for trend < .0001 for both). C-peptide concentrations were not associated with n-3 polyunsaturated fatty acids. C-peptide concentrations significantly increased as δ-9-desaturase (16:1 n-7/16:0) and δ-6-desaturase (18:3 n-6/18:2 n-6) increased (P for trend = .01 and .03, respectively) and δ-5-desaturase (20:4 n-6/20:3 n-6) decreased (P for trend = .004). In conclusion, a fatty acid pattern with high levels of serum stearic, palmitoleic, or dihomo-γ-linolenic acids; δ-9-desaturase (16:1 n-7/16:0) or δ-6-desaturase (18:3 n-6/18:2 n-6) activities; and low levels of serum linoleic acid or δ-5-desaturase (20:4 n-6/20:3 n-6) activity might be associated with higher insulin resistance in Japanese adults.

  15. Process for solidifying high-level nuclear waste

    DOEpatents

    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.

  16. Morphological and physiological changes exhibited by a Cd-resistant Dictyosphaerium chlorelloides strain and its cadmium removal capacity.

    PubMed

    Bartolomé, M C; Cortés, A A; Sánchez-Fortún, A; Garnica-Romo, M G; Sánchez-Carrillo, S; Sánchez-Fortún, Sebastián

    2016-12-01

    Changes induced on freshwater microalga Dictyosphaerium chlorelloides (Dc(wt)) acclimated in the laboratory until their survival in culture media enriched with cadmium 100 µM have been studied. Cadmium removal by living cells of this Cd-resistant (Dc(CdR100)) strain was tested in cultures exposed to 100 µM Cd during 30 days. Cell dimensions were measured under light microscopy, and cell growth was studied. Photosynthetic yield (ΦPSII) was analyzed and the photosynthetic oxygen development and respiration response was obtained. Results show that Dc(CdR100) strain exhibited significant cell morphology changes in comparison to Dc(wt) cells, which affected both surface area and cell biovolume. Malthusian fitness analysis showed that Dc(CdR100) strain living in Cd-enriched culture had developed a lower capacity of nearly 50% growth, and its photosynthetic oxygen development and respiration response were significantly reduced in both light and dark photosynthetic phases. Dc(CdR100) strain showed a very high capacity to remove cadmium from the aquatic environment (over 90%), although most of the removed heavy metal (≈70%) is adhered to the cell wall. These specific characteristics of Dc(CdR100) cells suggest the possibility of using this strain in conjunction with Dc(wt) strain as bioelements into a dual-head biosensor, and in bioremediation processes on freshwater polluted with Cd. PMID:27222159

  17. The CMS high level trigger

    NASA Astrophysics Data System (ADS)

    Gori, Valentina

    2014-05-01

    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.

  18. The CMS High Level Trigger

    NASA Astrophysics Data System (ADS)

    Trocino, Daniele

    2014-06-01

    The CMS experiment has been designed with a two-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.

  19. Optimizing High Level Waste Disposal

    SciTech Connect

    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

  20. Candidate Genes That May Be Responsible for the Unusual Resistances Exhibited by Bacillus pumilus SAFR-032 Spores

    PubMed Central

    Tirumalai, Madhan R.; Rastogi, Rajat; Zamani, Nader; O’Bryant Williams, Elisha; Allen, Shamail; Diouf, Fatma; Kwende, Sharon; Weinstock, George M.; Venkateswaran, Kasthuri J.; Fox, George E.

    2013-01-01

    The spores of several Bacillus species, including Bacillus pumilus SAFR-032 and B. safensis FO-36b, which were isolated from the spacecraft assembly facility at NASA's Jet Propulsion Laboratory, are unusually resistant to UV radiation and hydrogen peroxide. In order to identify candidate genes that might be associated with these resistances, the whole genome of B. pumilus SAFR-032, and the draft genome of B. safensis FO-36b were compared in detail with the very closely related type strain B. pumilus ATCC7061T. 170 genes are considered characteristic of SAFR-032, because they are absent from both FO-36b and ATCC7061T. Forty of these SAFR-032 characteristic genes are entirely unique open reading frames. In addition, four genes are unique to the genomes of the resistant SAFR-032 and FO-36b. Fifty three genes involved in spore coat formation, regulation and germination, DNA repair, and peroxide resistance, are missing from all three genomes. The vast majority of these are cleanly deleted from their usual genomic context without any obvious replacement. Several DNA repair and peroxide resistance genes earlier reported to be unique to SAFR-032 are in fact shared with ATCC7061T and no longer considered to be promising candidates for association with the elevated resistances. Instead, several SAFR-032 characteristic genes were identified, which along with one or more of the unique SAFR-032 genes may be responsible for the elevated resistances. These new candidates include five genes associated with DNA repair, namely, BPUM_0608 a helicase, BPUM_0652 an ATP binding protein, BPUM_0653 an endonuclease, BPUM_0656 a DNA cytosine-5- methyltransferase, and BPUM_3674 a DNA helicase. Three of these candidate genes are in immediate proximity of two conserved hypothetical proteins, BPUM_0654 and BPUM_0655 that are also absent from both FO-36b and ATCC7061T. This cluster of five genes is considered to be an especially promising target for future experimental work. PMID:23799069

  1. Fracture resistance exhibited by endodontically treated and retreated teeth shaped by ProTaper NEXT versus WaveOne: An in vitro study

    PubMed Central

    Khalap, Neha Deepak; Hegde, Vibha; Kokate, Sharad

    2015-01-01

    Aim: To compare the fracture resistance exhibited by teeth after primary endodontic treatment and retreatment. Materials and Methods: One hundred freshly extracted human teeth were selected. 20 samples served as control (untreated). Eighty experimental samples were divided into two groups (n = 40) for instrumentation using rotary Protaper NEXT (PTN) or reciprocating WaveOne (WO) files and obturated using warm lateral compaction. Half of the samples (n = 20) from each group were subjected to a load. The remaining half were subjected to retreatment using Protaper universal retreatment files (RFs) followed by a file larger than the master apical file used in groups 1 and 2 and reobturated. Group A: Control, Group B: PTN + obturation, Group C: WO + obturation, Group D: RF + PTN + obturation and Group E: RF + WO + obturation. The retreatment specimens were also subjected to load and the readings acquired were statistically analyzed. Result: When compared between the groups, control group exhibited the highest fracture resistance (P < 0.01). When multiple tests were performed, Group E exhibited significantly less fracture resistance (P < 0.01). Conclusion: Endodontic treatment and retreatment both results in lowering the fracture resistance of a tooth. PMID:26752838

  2. Introduced Brassica nigra populations exhibit greater growth and herbivore resistance but less tolerance than native populations in the native range.

    PubMed

    Oduor, Ayub M O; Lankau, Richard A; Strauss, Sharon Y; Gómez, José M

    2011-07-01

    Rapid post-introduction evolution has been found in many invasive plant species, and includes changes in defence (resistance and tolerance) and competitive ability traits. Here, we explored the post-introduction evolution of a trade-off between resistance to and tolerance of herbivory, which has received little attention. In a common garden experiment in a native range, nine invasive and 16 native populations of Brassica nigra were compared for growth and defence traits. Invasive populations had higher resistance to, but lower tolerance of, herbivore damage than native populations. Invasive populations survived better and produced more seeds than native ones when released from herbivores; but fitness was equivalent between the regions under ambient herbivory. The invasive populations grew taller, and produced more biomass and lighter seeds than natives, irrespective of insecticide treatment. In addition to supporting the idea of post-introduction rapid evolution of plant traits, our results also contribute to an emerging pattern of both increasing resistance and growth in invasive populations, contrary to the predictions of earlier theories of resistance-growth trade-offs. PMID:21410474

  3. 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?

    PubMed

    Golparian, Daniel; Fernandes, Prabhavathi; Ohnishi, Makoto; Jensen, Jörgen S; Unemo, Magnus

    2012-05-01

    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.

  4. 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

    PubMed Central

    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

  5. Transgenic soybean overexpressing GmSAMT1 exhibits resistance to multiple-HG types of soybean cyst nematode Heterodera glycines

    DOE PAGES

    Lin, Jingyu; Mazarei, Mitra; Zhao, Nan; Hatcher, Catherine N.; Wuddineh, Wegi A.; Rudis, Mary; Tschaplinski, Timothy J.; Pantalone, Vincent R.; Arelli, Prakash R.; Hewezi, Tarek; et al

    2016-05-23

    Soybean (Glycine max (L.) Merr.) salicylic acid methyl transferase (GmSAMT1) catalyses the conversion of salicylic acid to methyl salicylate. Prior results showed that when GmSAMT1 was overexpressed in transgenic soybean hairy roots, resistance is conferred against soybean cyst nematode (SCN), Heterodera glycines Ichinohe. In this study, we produced transgenic soybean overexpressing GmSAMT1 and characterized their response to various SCN races. Transgenic plants conferred a significant reduction in the development of SCN HG type 1.2.5.7 (race 2), HG type 0 (race 3) and HG type 2.5.7 (race 5). Among transgenic lines, GmSAMT1 expression in roots was positively associated with SCN resistance.more » In some transgenic lines, there was a significant decrease in salicylic acid titer relative to control plants. No significant seed yield differences were observed between transgenics and control soybean plants grown in one greenhouse with 22 °C day/night temperature, whereas transgenic soybean had higher yield than controls grown a warmer greenhouse (27 °C day/23 °C night) temperature. In a 1-year field experiment in Knoxville, TN, there was no significant difference in seed yield between the transgenic and nontransgenic soybean under conditions with negligible SCN infection. We hypothesize that GmSAMT1 expression affects salicylic acid biosynthesis, which, in turn, attenuates SCN development, without negative consequences to soybean yield or other morphological traits. Furthermore, we conclude that GmSAMT1 overexpression confers broad resistance to multiple SCN races, which would be potentially applicable to commercial production.« less

  6. Transgenic Sugarcane with a cry1Ac Gene Exhibited Better Phenotypic Traits and Enhanced Resistance against Sugarcane Borer

    PubMed Central

    Gao, Shiwu; Yang, Yingying; Wang, Chunfeng; Guo, Jinlong; Zhou, Dinggang; Wu, Qibin; Su, Yachun; Xu, Liping

    2016-01-01

    We developed sugarcane plants with improved resistance to the sugarcane borer, Diatraea saccharalis (F). An expression vector pGcry1Ac0229, harboring the cry1Ac gene and the selectable marker gene, bar, was constructed. This construct was introduced into the sugarcane cultivar FN15 by particle bombardment. Transformed plantlets were identified after selection with Phosphinothricin (PPT) and Basta. Plantlets were then screened by PCR based on the presence of cry1Ac and 14 cry1Ac positive plantlets were identified. Real-time quantitative PCR (RT-qPCR) revealed that the copy number of cry1Ac gene in the transgenic lines varied from 1 to 148. ELISA analysis showed that Cry1Ac protein levels in 7 transgenic lines ranged from 0.85 μg/FWg to 70.92 μg/FWg in leaves and 0.04 μg/FWg to 7.22 μg/FWg in stems, and negatively correlated to the rate of insect damage that ranged from 36.67% to 13.33%, respectively. Agronomic traits of six transgenic sugarcane lines with medium copy numbers were similar to the non-transgenic parental line. However, phenotype was poor in lines with high or low copy numbers. Compared to the non-transgenic control plants, all transgenic lines with medium copy numbers had relatively equal or lower sucrose yield and significantly improved sugarcane borer resistance, which lowered susceptibility to damage by insects. This suggests that the transgenic sugarcane lines harboring medium copy numbers of the cry1Ac gene may have significantly higher resistance to sugarcane borer but the sugarcane yield in these lines is similar to the non-transgenic control thus making them superior to the control lines. PMID:27093437

  7. Transgenic Sugarcane with a cry1Ac Gene Exhibited Better Phenotypic Traits and Enhanced Resistance against Sugarcane Borer.

    PubMed

    Gao, Shiwu; Yang, Yingying; Wang, Chunfeng; Guo, Jinlong; Zhou, Dinggang; Wu, Qibin; Su, Yachun; Xu, Liping; Que, Youxiong

    2016-01-01

    We developed sugarcane plants with improved resistance to the sugarcane borer, Diatraea saccharalis (F). An expression vector pGcry1Ac0229, harboring the cry1Ac gene and the selectable marker gene, bar, was constructed. This construct was introduced into the sugarcane cultivar FN15 by particle bombardment. Transformed plantlets were identified after selection with Phosphinothricin (PPT) and Basta. Plantlets were then screened by PCR based on the presence of cry1Ac and 14 cry1Ac positive plantlets were identified. Real-time quantitative PCR (RT-qPCR) revealed that the copy number of cry1Ac gene in the transgenic lines varied from 1 to 148. ELISA analysis showed that Cry1Ac protein levels in 7 transgenic lines ranged from 0.85 μg/FWg to 70.92 μg/FWg in leaves and 0.04 μg/FWg to 7.22 μg/FWg in stems, and negatively correlated to the rate of insect damage that ranged from 36.67% to 13.33%, respectively. Agronomic traits of six transgenic sugarcane lines with medium copy numbers were similar to the non-transgenic parental line. However, phenotype was poor in lines with high or low copy numbers. Compared to the non-transgenic control plants, all transgenic lines with medium copy numbers had relatively equal or lower sucrose yield and significantly improved sugarcane borer resistance, which lowered susceptibility to damage by insects. This suggests that the transgenic sugarcane lines harboring medium copy numbers of the cry1Ac gene may have significantly higher resistance to sugarcane borer but the sugarcane yield in these lines is similar to the non-transgenic control thus making them superior to the control lines.

  8. Multidrug-resistant hela cells overexpressing MRP1 exhibit sensitivity to cell killing by hyperthermia: Interactions with etoposide

    SciTech Connect

    Souslova, Tatiana; Averill-Bates, Diana A. . E-mail: averill.diana@uqam.ca

    2004-12-01

    Purpose: Multidrug resistance (MDR) remains one of the primary obstacles in cancer chemotherapy and often involves overexpression of drug efflux transporters such as P-glycoprotein and multidrug resistance protein 1 (MRP1). Regional hyperthermia is undergoing clinical investigation in combination with chemotherapy or radiotherapy. This study evaluates whether hyperthermia can reverse MDR mediated by MRP1 in human cervical adenocarcinoma (HeLa) cells. Methods and materials: Cytotoxicity of hyperthermia and/or etoposide was evaluated using sulforhodamine-B in HeLa cells overexpressing MRP1 and their drug-sensitive counterparts. Glutathione, glutathione peroxidase (GPx), and glutathione S-transferase (GST) were quantified by spectrophotometry. GST isoenzymes were quantified by immunodetection. Caspase activation was evaluated by fluorometry and chromatin condensation by fluorescence microscopy using Hoechst 33258. Necrosis was determined using propidium iodide. Results: The major finding is that HeLa and HeLaMRP cells are both sensitive to cytotoxicity of hyperthermia (41-45 deg C). Hyperthermia induced activation of caspase 3 and chromatin condensation. Although total levels of cell killing were similar, there was a switch from apoptotic to necrotic cell death in MDR cells. This could be explained by decreased glutathione and GPx in MDR cells. MDR cells also contained very low levels of GST and were resistant to etoposide-induced apoptosis. Hyperthermia caused a modest increase in etoposide-induced apoptosis in HeLa and HeLaMRP cells, which required appropriate heat-drug scheduling. Conclusions: Hyperthermia could be useful in eliminating MDR cells that overexpress MRP1.

  9. Src Is a Potential Therapeutic Target in Endocrine-Resistant Breast Cancer Exhibiting Low Estrogen Receptor-Mediated Transactivation

    PubMed Central

    Pancholi, Sunil; Nikitorowicz-Buniak, Joanna; Simigdala, Nikiana; Dowsett, Mitch; Johnston, Stephen R.; Martin, Lesley-Ann

    2016-01-01

    Despite the effectiveness of endocrine therapies in estrogen receptor positive (ER+) breast cancer, approximately 40% of patients relapse. Previously, we identified the Focal-adhesion kinase canonical pathway as a major contributor of resistance to estrogen deprivation and cellular-sarcoma kinase (c-src) as a dominant gene in this pathway. Dasatinib, a pan-src inhibitor, has recently been used in clinical trials to treat ER+ patients but has shown mixed success. In the following study, using isogenic cell line models, we provide a potential explanation for these findings and suggest a sub-group that may benefit. A panel of isogenic cell lines modelling resistance to aromatase inhibitors (LTED) and tamoxifen (TAMR) were assessed for response to dasatinib ± endocrine therapy. Dasatinib caused a dose-dependent decrease in proliferation in MCF7-TAMR cells and resensitized them to tamoxifen and fulvestrant but not in HCC1428-TAMR. In contrast, in estrogen-deprived conditions, dasatinib increased the proliferation rate of parental-MCF7 cells and had no effect on MCF7-LTED or HCC1428-LTED. Treatment with dasatinib caused a decrease in src-phosphorylation and inhibition of downstream pathways, including AKT and ERK1/2 in all cell lines tested, but only the MCF7-TAMR showed a concomitant decrease in markers of cell cycle progression. Inhibition of src also caused a significant decrease in cell migration in both MCF7-LTED and MCF7-TAMR cells. Finally, we showed that, in MCF7-TAMR cells, in contrast to tamoxifen sensitive cell lines, ER is expressed throughout the cell rather than being restricted to the nucleus and that treatment with dasatinib resulted in nuclear shuttling of ER, which was associated with an increase in ER-mediated transcription. These data suggest that src has differential effects in endocrine-resistant cell lines, particularly in tamoxifen resistant models, with low ER genomic activity, providing further evidence of the importance of patient selection

  10. Bell and banana pepper exhibit mature-plant resistance to tomato spotted wilt Tospovirus transmitted by Frankliniella fusca (Thysanoptera: Thripidae).

    PubMed

    Beaudoin, A L P; Kahn, N D; Kennedy, G G

    2009-02-01

    Tomato spotted wilt virus (family Bunyaviridae, genus Tospovirus, TSWV) causes annual economic losses in pepper, Capsicum annuum L., across the southern United States and is transmitted by several species of thrips, including the tobacco thrips, Frankliniella fusca (Hinds). Reduced virus transmission and symptom severity as plant age increases is known as mature-plant resistance. TSWV transmission to pepper plants was examined in three and four age classes in field and greenhouse trials, respectively. In the field trial, 'Camelot' bell pepper plants were exposed to potentially viruliferous F. fusca 37, 51, or 65 d postsowing. Two greenhouse trials of Camelot bell and one trial each of 'Bounty' and 'Pageant' banana pepper plants were exposed to potentially viruliferous F. fusca, 43, 57, 71, or 85; 48, 62, 75, or 90; 42, 56, 70, or 84; and 43, 57, 71, or 85 d postsowing, respectively. Linear and hyperbolic regressions of percentage of infected plants per block on days postsowing indicated mature-plant resistance in all trials. All models were significant, but hyperbolic curves better fit the data than linear models. Hyperbolic models were used to calculate the number of days posttransplant at which a 50% decrease from the predicted percentage of infected plants at transplant age (42 d postsowing) was expected. This was referred to as days posttransplant-50 (DPT50). DPRT50 occurred within 9 days posttransplant age for all trials, indicating that early TSWV management in pepper is critical.

  11. Transgenic Brassica juncea plants expressing MsrA1, a synthetic cationic antimicrobial peptide, exhibit resistance to fungal phytopathogens.

    PubMed

    Rustagi, Anjana; Kumar, Deepak; Shekhar, Shashi; Yusuf, Mohd Aslam; Misra, Santosh; Sarin, Neera Bhalla

    2014-06-01

    Cationic antimicrobial peptides (CAPs) have shown potential against broad spectrum of phytopathogens. Synthetic versions with desirable properties have been modeled on these natural peptides. MsrA1 is a synthetic chimera of cecropin A and melittin CAPs with antimicrobial properties. We generated transgenic Brassica juncea plants expressing the msrA1 gene aimed at conferring fungal resistance. Five independent transgenic lines were evaluated for resistance to Alternaria brassicae and Sclerotinia sclerotiorum, two of the most devastating pathogens of B. juncea crops. In vitro assays showed inhibition by MsrA1 of Alternaria hyphae growth by 44-62 %. As assessed by the number and size of lesions and time taken for complete leaf necrosis, the Alternaria infection was delayed and restricted in the transgenic plants with the protection varying from 69 to 85 % in different transgenic lines. In case of S. sclerotiorum infection, the lesions were more severe and spread profusely in untransformed control compared with transgenic plants. The sclerotia formed in the stem of untransformed control plants were significantly more in number and larger in size than those present in the transgenic plants where disease protection of 56-71.5 % was obtained. We discuss the potential of engineering broad spectrum biotic stress tolerance by transgenic expression of CAPs in crop plants.

  12. Transgenic Brassica juncea plants expressing MsrA1, a synthetic cationic antimicrobial peptide, exhibit resistance to fungal phytopathogens.

    PubMed

    Rustagi, Anjana; Kumar, Deepak; Shekhar, Shashi; Yusuf, Mohd Aslam; Misra, Santosh; Sarin, Neera Bhalla

    2014-06-01

    Cationic antimicrobial peptides (CAPs) have shown potential against broad spectrum of phytopathogens. Synthetic versions with desirable properties have been modeled on these natural peptides. MsrA1 is a synthetic chimera of cecropin A and melittin CAPs with antimicrobial properties. We generated transgenic Brassica juncea plants expressing the msrA1 gene aimed at conferring fungal resistance. Five independent transgenic lines were evaluated for resistance to Alternaria brassicae and Sclerotinia sclerotiorum, two of the most devastating pathogens of B. juncea crops. In vitro assays showed inhibition by MsrA1 of Alternaria hyphae growth by 44-62 %. As assessed by the number and size of lesions and time taken for complete leaf necrosis, the Alternaria infection was delayed and restricted in the transgenic plants with the protection varying from 69 to 85 % in different transgenic lines. In case of S. sclerotiorum infection, the lesions were more severe and spread profusely in untransformed control compared with transgenic plants. The sclerotia formed in the stem of untransformed control plants were significantly more in number and larger in size than those present in the transgenic plants where disease protection of 56-71.5 % was obtained. We discuss the potential of engineering broad spectrum biotic stress tolerance by transgenic expression of CAPs in crop plants. PMID:24452332

  13. Biofilm-Forming Methicillin-Resistant Staphylococcus aureus Survive in Kupffer Cells and Exhibit High Virulence in Mice

    PubMed Central

    Oyama, Takuto; Miyazaki, Motoyasu; Yoshimura, Michinobu; Takata, Tohru; Ohjimi, Hiroyuki; Jimi, Shiro

    2016-01-01

    Although Staphylococcus aureus is part of the normal body flora, heavy usage of antibiotics has resulted in the emergence of methicillin-resistant strains (MRSA). MRSA can form biofilms and cause indwelling foreign body infections, bacteremia, soft tissue infections, endocarditis, and osteomyelitis. Using an in vitro assay, we screened 173 clinical blood isolates of MRSA and selected 20 high-biofilm formers (H-BF) and low-biofilm formers (L-BF). These were intravenously administered to mice and the general condition of mice, the distribution of bacteria, and biofilm in the liver, lung, spleen, and kidney were investigated. MRSA count was the highest in the liver, especially within Kupffer cells, which were positive for acid polysaccharides that are associated with intracellular biofilm. After 24 h, the general condition of the mice worsened significantly in the H-BF group. In the liver, bacterial deposition and aggregation and the biofilm-forming spot number were all significantly greater for H-BF group than for L-BF. CFU analysis revealed that bacteria in the H-BF group survived for long periods in the liver. These results indicate that the biofilm-forming ability of MRSA is a crucial factor for intracellular persistence, which could lead to chronic infections. PMID:27376326

  14. A newly isolated Chlorella sp. from desert sand crusts exhibits a unique resistance to excess light intensity.

    PubMed

    Treves, Haim; Raanan, Hagai; Finkel, Omri M; Berkowicz, Simon M; Keren, Nir; Shotland, Yoram; Kaplan, Aaron

    2013-12-01

    We recently isolated a small green alga from a biological sand crust (BSC) in the NW Negev, Israel. Based on its 18S rRNA and rbcL genes, it is a close relative of Chlorella sorokiniana and of certain strains of C. vulgaris and C. variabilis, but differs substantially in many aspects from C. sorokiniana. Because the classification of Chlorellales is still not resolved, we designated this species as C. ohadii (Trebouxiophyceae) in honor of Professor Itzhak Ohad. Under controlled laboratory conditions, C. ohadii showed marked structural and photosynthetic performance changes, depending on the carbon source used during growth, as well as remarkable resistance to photoinhibition. CO2 -dependent O2 evolution was not affected even when exposed to a light intensity of 3500 μmole photons m(-2)  s(-1) , over 1.5 times the maximal intensity reached at the BSC surface, whereas the variable fluorescence declined sharply. We briefly discuss the use of fluorescence to assess photosynthetic rate and the implications of this finding for the assessment of global BSCs activity.

  15. The novel tankyrase inhibitor (AZ1366) enhances irinotecan activity in tumors that exhibit elevated tankyrase and irinotecan resistance

    PubMed Central

    Quackenbush, Kevin S.; Bagby, Stacey; Tai, Wai Meng; Messersmith, Wells A.; Schreiber, Anna; Greene, Justin; Kim, Jihye; Wang, Guoliang; Purkey, Alicia; Pitts, Todd M.; Nguyen, Anna; Gao, Dexiang; Blatchford, Patrick; Capasso, Anna; Schuller, Alwin G.; Eckhardt, S. Gail; Arcaroli, John J.

    2016-01-01

    Background Dysregulation of the canonical Wnt signaling pathway has been implicated in colorectal cancer (CRC) development as well as incipient stages of malignant transformation. In this study, we investigated the antitumor effects of AZ1366 (a novel tankyrase inhibitor) as a single agent and in combination with irinotecan in our patient derived CRC explant xenograft models. Results Six out of 18 CRC explants displayed a significant growth reduction to AZ1366. There was one CRC explant (CRC040) that reached the threshold of sensitivity (TGII ≤ 20%) in this study. In addition, the combination of AZ1366 + irinotecan demonstrated efficacy in 4 out of 18 CRC explants. Treatment effects on the WNT pathway revealed that tankyrase inhibition was ineffective at reducing WNT dependent signaling. However, the anti-tumor effects observed in this study were likely a result of alternative tankyrase effects whereby tankyrase inhibition reduced NuMA levels. Materials and Methods Eighteen CRC explants were treated with AZ1366 single agent or in combination for 28 days and treatment responses were assessed. Pharmacokinetic (AZ1366 drug concentrations) and pharmacodynamic effects (Axin2 levels) were investigated over 48 hours. Immunohistochemistry of nuclear β-catenin levels as well as western blot was employed to examine the treatment effects on the WNT pathway as well as NuMA. Conclusions Combination AZ1366 and irinotecan achieved greater anti-tumor effects compared to monotherapy. Activity was limited to CRC explants that displayed irinotecan resistance and increased protein levels of tankyrase and NuMA. PMID:27070088

  16. Transgenic rice with inducible ethylene production exhibits broad-spectrum disease resistance to the fungal pathogens Magnaporthe oryzae and Rhizoctonia solani.

    PubMed

    Helliwell, Emily E; Wang, Qin; Yang, Yinong

    2013-01-01

    Rice blast (Magnaporthe oryzae) and sheath blight (Rhizoctonia solani) are the two most devastating diseases of rice (Oryza sativa), and have severe impacts on crop yield and grain quality. Recent evidence suggests that ethylene (ET) may play a more prominent role than salicylic acid and jasmonic acid in mediating rice disease resistance. In this study, we attempt to genetically manipulate endogenous ET levels in rice for enhancing resistance to rice blast and sheath blight diseases. Transgenic lines with inducible production of ET were generated by expressing the rice ACS2 (1-aminocyclopropane-1-carboxylic acid synthase, a key enzyme of ET biosynthesis) transgene under control of a strong pathogen-inducible promoter. In comparison with the wild-type plant, the OsACS2-overexpression lines showed significantly increased levels of the OsACS2 transcripts, endogenous ET and defence gene expression, especially in response to pathogen infection. More importantly, the transgenic lines exhibited increased resistance to a field isolate of R. solani, as well as different races of M. oryzae. Assessment of the growth rate, generational time and seed production revealed little or no differences between wild type and transgenic lines. These results suggest that pathogen-inducible production of ET in transgenic rice can enhance resistance to necrotrophic and hemibiotrophic fungal pathogens without negatively impacting crop productivity.

  17. Mammary Stem Cells and Tumor-Initiating Cells Are More Resistant to Apoptosis and Exhibit Increased DNA Repair Activity in Response to DNA Damage

    PubMed Central

    Chang, Chi-Hsuan; Zhang, Mei; Rajapakshe, Kimal; Coarfa, Cristian; Edwards, Dean; Huang, Shixia; Rosen, Jeffrey M.

    2015-01-01

    Summary Adult stem cells and tumor-initiating cells (TICs) often employ different mechanisms of DNA damage response (DDR) as compared to other tissue cell types. However, little is known about how mammary stem cells (MaSCs) and mammary TICs respond to DNA damage. Using the mouse mammary gland and syngeneic p53-null tumors as models, we investigated the molecular and physiological consequences of DNA damage in wild-type MaSCs, p53-null MaSCs, and p53-null TICs. We showed that wild-type MaSCs and basal cells are more resistant to apoptosis and exhibit increased non-homologous end joining (NHEJ) activity. Loss of p53 in mammary epithelium affected both cell-cycle regulation and DNA repair efficiency. In p53-null tumors, we showed that TICs are more resistant to ionizing radiation (IR) due to decreased apoptosis, elevated NHEJ activity, and more-rapid DNA repair. These results have important implications for understanding DDR mechanisms involved in both tumorigenesis and therapy resistance. PMID:26300228

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

    DOEpatents

    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.

  19. New Zealand white rabbit progeny exposed in utero to methanol are resistant to skeletal anomalies reported for rodents, but exhibit a novel vertebral defect.

    PubMed

    Sweeting, J Nicole; Wells, Peter G

    2015-12-01

    Rabbits may serve as a useful model for predicting the human risk for methanol (MeOH) teratogenicity, which currently is unknown. New Zealand white (NZW) rabbits are resistant to the MeOH-initiated gross morphological anomalies characteristically observed in several strains of mice and rats, but skeletal development has not been assessed. Pregnant rabbits were administered 2 doses of 2g/kg MeOH on gestational day (GD) 7 or 8, and assessed for skeletal abnormalities on GD 29. Variations between treated and control fetuses were observed only in the number of post-lumbar vertebrae, where MeOH-exposed fetuses had fewer ossified vertebrae, which has not been reported for rodents. Furthermore, rabbits did not exhibit the MeOH-initiated skeletal defects characteristically reported for rodent fetuses. These results expand the morphological breadth of the relative species-dependent resistance of rabbits to MeOH teratogenicity compared to rodents, yet reveal a novel skeletal defect or delay in ossification not reported for rodents.

  20. Fucoidan from sea cucumber Cucumaria frondosa exhibits anti-hyperglycemic effects in insulin resistant mice via activating the PI3K/PKB pathway and GLUT4.

    PubMed

    Wang, Yiming; Wang, Jingfeng; Zhao, Yanlei; Hu, Shiwei; Shi, Di; Xue, Changhu

    2016-01-01

    The present study investigated the anti-hyperglycemic properties and mechanisms of fucoidan, isolated from Cucumaria frondosa (Cf-FUC), in insulin resistant mice. Male C57BL/6J mice were fed regular diet or high-fat/high-sucrose diet for 19 weeks. Model animals were dietary administrated either rosiglitazone (RSG, 1 mg/kg·bw), fucoidan (Cf-FUC, 80 mg/kg·bw) or their combinations. Results showed that Cf-FUC significantly reduced fasting blood glucose and insulin levels, and enhanced glucose tolerance and insulin tolerance in insulin-resistant mice. Quantitative real-time PCR analysis showed that Cf-FUC increased the mRNA expressions of insulin receptors (IR), insulin receptor substrate 1 (IRS-1), phosphatidylinositol 3 kinase (PI3K), protein kinase B (PKB), and glucose transporter 4 (GLUT4). Western blot assays demonstrated that Cf-FUC showed no effect on total protein expression but nevertheless enhanced the phosphorylation of proteins listed above and increased translocation of GLUT4 to the cell membrane. Furthermore, Cf-FUC enhanced the effects of RSG. These results indicated that Cf-FUC exhibited significant anti-hyperglycemic effects via activating PI3K/PKB pathway and GLUT4 in skeletal muscle and adipose tissue.

  1. High-level waste processing and disposal

    NASA Astrophysics Data System (ADS)

    Crandall, J. L.; Drause, H.; Sombret, C.; Uematsu, K.

    The national high level waste disposal plans for France, the Federal Republic of Germany, Japan, and the United States are covered. Three conclusions are reached. The first conclusion is that an excellent technology already exists for high level waste disposal. With appropriate packaging, spent fuel seems to be an acceptable waste form. Borosilicate glass reprocessing waste forms are well understood, in production in France, and scheduled for production in the next few years in a number of other countries. For final disposal, a number of candidate geological repository sites have been identified and several demonstration sites opened. The second conclusion is that adequate financing and a legal basis for waste disposal are in place in most countries. Costs of high level waste disposal will probably and about 5 to 10% to the costs of nuclear electric power. Third conclusion is less optimistic.

  2. A Software Architecture for High Level Applications

    SciTech Connect

    Shen,G.

    2009-05-04

    A modular software platform for high level applications is under development at the National Synchrotron Light Source II project. This platform is based on client-server architecture, and the components of high level applications on this platform will be modular and distributed, and therefore reusable. An online model server is indispensable for model based control. Different accelerator facilities have different requirements for the online simulation. To supply various accelerator simulators, a set of narrow and general application programming interfaces is developed based on Tracy-3 and Elegant. This paper describes the system architecture for the modular high level applications, the design of narrow and general application programming interface for an online model server, and the prototype of online model server.

  3. Outdoor Exhibits

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The National Data Buoy Center (NDBC) at the John C. Stennis Space Center has exhibits located in front of the Visitors Center. These boat-shaped buoys are moored in areas of the ocean that experience hostile environmental conditions. The instruments installed gather information and relay it to the National Weather Service by satellite. Nomad buoys are 20 feet long and weigh 13,900 pounds. They provide information on wind speed and direction, humidity levels, air and sea surface temperature and air pressure. U.S. Coast Guard ships transport buoys to their mooring sites.

  4. High-Level Application Framework for LCLS

    SciTech Connect

    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.

  5. PAIRWISE BLENDING OF HIGH LEVEL WASTE (HLW)

    SciTech Connect

    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.

  6. High-level radioactive wastes. Supplement 1

    SciTech Connect

    McLaren, L.H.

    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.

  7. Do we understand high-level vision?

    PubMed

    Cox, David Daniel

    2014-04-01

    'High-level' vision lacks a single, agreed upon definition, but it might usefully be defined as those stages of visual processing that transition from analyzing local image structure to analyzing structure of the external world that produced those images. Much work in the last several decades has focused on object recognition as a framing problem for the study of high-level visual cortex, and much progress has been made in this direction. This approach presumes that the operational goal of the visual system is to read-out the identity of an object (or objects) in a scene, in spite of variation in the position, size, lighting and the presence of other nearby objects. However, while object recognition as a operational framing of high-level is intuitive appealing, it is by no means the only task that visual cortex might do, and the study of object recognition is beset by challenges in building stimulus sets that adequately sample the infinite space of possible stimuli. Here I review the successes and limitations of this work, and ask whether we should reframe our approaches to understanding high-level vision.

  8. Overexpression of ShCYP51B and ShatrD in Sclerotinia homoeocarpa isolates exhibiting practical field resistance to a demethylation inhibitor fungicide.

    PubMed

    Hulvey, Jon; Popko, James T; Sang, Hyunkyu; Berg, Andrew; Jung, Geunhwa

    2012-09-01

    We investigated genetic factors that govern the reduced propiconazole sensitivity of Sclerotinia homoeocarpa field isolates collected during a 2-year field efficacy study on dollar spot disease of turf in five New England sites. These isolates displayed a >50-fold range of in vitro sensitivity to a sterol demethylation inhibitor (DMI) fungicide, propiconazole, making them ideal for investigations of genetic mechanisms of reduced DMI sensitivity. The CYP51 gene homolog in S. homoeocarpa (ShCYP51B), encoding the enzyme target of DMIs, is likely a minor genetic factor for reduced propiconazole sensitivity, since there were no differences in constitutive relative expression (RE) values and only 2-fold-higher induced RE values for insensitive than for sensitive isolate groups. Next, we mined RNA-Seq transcriptome data for additional genetic factors and found evidence for the overexpression of a homolog of Botrytis cinerea atrD (BcatrD), ShatrD, a known efflux transporter of DMI fungicides. The ShatrD gene showed much higher constitutive and induced RE values for insensitive isolates. Several polymorphisms were found upstream of ShatrD but were not definitively linked to overexpression. The screening of constitutive RE values of ShCYP51B and ShatrD in isolates from two golf courses that exhibited practical field resistance to propiconazole uncovered evidence for significant population-specific overexpression of both genes. However, linear regression demonstrated that the RE of ShatrD displays a more significant relationship with propiconazole sensitivity than that of ShCYP51B. In summary, our results suggest that efflux is a major determinant of the reduced DMI sensitivity of S. homoeocarpa genotypes in New England, which may have implications for the emergence of practical field resistance in this important turfgrass pathogen.

  9. Mice Deficient in Proglucagon-Derived Peptides Exhibit Glucose Intolerance on a High-Fat Diet but Are Resistant to Obesity.

    PubMed

    Takagi, Yusuke; Kinoshita, Keita; Ozaki, Nobuaki; Seino, Yusuke; Murata, Yoshiharu; Oshida, Yoshiharu; Hayashi, Yoshitaka

    2015-01-01

    Homozygous glucagon-GFP knock-in mice (Gcggfp/gfp) lack proglucagon derived-peptides including glucagon and GLP-1, and are normoglycemic. We have previously shown that Gcggfp/gfp show improved glucose tolerance with enhanced insulin secretion. Here, we studied glucose and energy metabolism in Gcggfp/gfp mice fed a high-fat diet (HFD). Male Gcggfp/gfp and Gcggfp/+ mice were fed either a normal chow diet (NCD) or an HFD for 15-20 weeks. Regardless of the genotype, mice on an HFD showed glucose intolerance, and Gcggfp/gfp mice on HFD exhibited impaired insulin secretion whereas Gcggfp/+ mice on HFD exhibited increased insulin secretion. A compensatory increase in β-cell mass was observed in Gcggfp/+mice on HFD, but not in Gcggfp/gfp mice on the same diet. Weight gain was significantly lower in Gcggfp/gfp mice than in Gcggfp/+mice. Oxygen consumption was enhanced in Gcggfp/gfp mice compared to Gcggfp/+ mice on an HFD. HFD feeding significantly increased uncoupling protein 1 mRNA expression in brown adipose and inguinal white adipose tissues of Gcggfp/gfp mice, but not of Gcggfp/+mice. Treatment with the glucagon-like peptide-1 receptor agonist liraglutide (200 mg/kg) improved glucose tolerance in Gcggfp/gfp mice and insulin content in Gcggfp/gfp and Gcggfp/+ mice was similar after liraglutide treatment. Our findings demonstrate that Gcggfp/gfp mice develop diabetes upon HFD-feeding in the absence of proglucagon-derived peptides, although they are resistant to diet-induced obesity.

  10. A Hybrid Cationic Peptide Composed of Human β-Defensin-1 and Humanized θ-Defensin Sequences Exhibits Salt-Resistant Antimicrobial Activity

    PubMed Central

    Nagaraj, Ramakrishnan; Motukupally, Swapna R.

    2014-01-01

    We have designed a hybrid peptide by combining sequences of human β-defensin-1 (HBD-1) and θ-defensin, in an attempt to generate a molecule that combines the diversity in structure and biological activity of two different peptides to yield a promising therapeutic candidate. HBD-1 was chosen as it is a natural defensin of humans that is constitutively expressed, but its antibacterial activity is considerably impaired by elevated ionic strength. θ-Defensins are expressed in human bone marrow as a pseudogene and are homologous to rhesus monkey circular minidefensins. Retrocyclins are synthetic human θ-defensins. The cyclic nature of the θ-defensin peptides makes them salt resistant, nonhemolytic, and virtually noncytotoxic in vitro. However, a nonhuman circular molecule developed for clinical use would be less viable than a linear molecule. In this study, we have fused the C-terminal region of HBD-1 to the nonapeptide sequence of a synthetic retrocyclin. Cyclization was achieved by joining the terminal ends of the hybrid peptide by a disulfide bridge. The hybrid peptide with or without the disulfide bridge exhibited enhanced antimicrobial activity against both Gram-negative and Gram-positive bacteria as well as against fungi, including clinical bacterial isolates from eye infections. The peptide retained activity in the presence of NaCl and serum and was nonhemolytic in vitro. Thus, the hybrid peptide generated holds potential as a new class of antibiotics. PMID:25348533

  11. High-Level Waste Melter Review

    SciTech Connect

    Ahearne, J.; Gentilucci, J.; Pye, L. D.; Weber, T.; Woolley, F.; Machara, N. P.; Gerdes, K.; Cooley, C.

    2002-02-26

    The U.S. Department of Energy (DOE) is faced with a massive cleanup task in resolving the legacy of environmental problems from years of manufacturing nuclear weapons. One of the major activities within this task is the treatment and disposal of the extremely large amount of high-level radioactive (HLW) waste stored at the Hanford Site in Richland, Washington. The current planning for the method of choice for accomplishing this task is to vitrify (glassify) this waste for disposal in a geologic repository. This paper describes the results of the DOE-chartered independent review of alternatives for solidification of Hanford HLW that could achieve major cost reductions with reasonable long-term risks, including recommendations on a path forward for advanced melter and waste form material research and development. The potential for improved cost performance was considered to depend largely on increased waste loading (fewer high-level waste canisters for disposal), higher throughput, or decreased vitrification facility size.

  12. High-Level Waste Melter Study Report

    SciTech Connect

    Perez, 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.

  13. Evaluation of stainless steel zirconium alloys as high-level nuclear waste forms

    NASA Astrophysics Data System (ADS)

    McDeavitt, S. M.; Abraham, D. P.; Park, J. Y.

    1998-09-01

    Stainless steel-zirconium (SS-Zr) alloys have been developed for the consolidation and disposal of waste stainless steel, zirconium, and noble metal fission products such as Nb, Mo, Tc, Ru, Pd, and Ag recovered from spent nuclear fuel assemblies. These remnant waste metals are left behind following electrometallurgical treatment, a molten salt-based process being demonstrated by Argonne National Laboratory. Two SS-Zr compositions have been selected as baseline waste form alloys: (a) stainless steel-15 wt% zirconium (SS-15Zr) for stainless steel-clad fuels and (b) zirconium-8 wt% stainless steel (Zr-8SS) for Zircaloy-clad fuels. Simulated waste form alloys were prepared and tested to characterize the metallurgy of SS-15Zr and Zr-8SS and to evaluate their physical properties and corrosion resistance. Both SS-15Zr and Zr-8SS have multi-phase microstructures, are mechanically strong, and have thermophysical properties comparable to other metals. They also exhibit high resistance to corrosion in simulated groundwater as determined by immersion, electrochemical, and vapor hydration tests. Taken together, the microstructure, physical property, and corrosion resistance data indicate that SS-15Zr and Zr-8SS are viable materials as high-level waste forms.

  14. Materials Science of High-Level Nuclear Waste Immobilization

    SciTech Connect

    Weber, William J.; Navrotsky, Alexandra; Stefanovsky, S. V.; Vance, E. R.; Vernaz, Etienne Y.

    2009-01-09

    With the increasing demand for the development of more nuclear power comes the responsibility to address the technical challenges of immobilizing high-level nuclear wastes in stable solid forms for interim storage or disposition in geologic repositories. The immobilization of high-level nuclear wastes has been an active area of research and development for over 50 years. Borosilicate glasses and complex ceramic composites have been developed to meet many technical challenges and current needs, although regulatory issues, which vary widely from country to country, have yet to be resolved. Cooperative international programs to develop advanced proliferation-resistant nuclear technologies to close the nuclear fuel cycle and increase the efficiency of nuclear energy production might create new separation waste streams that could demand new concepts and materials for nuclear waste immobilization. This article reviews the current state-of-the-art understanding regarding the materials science of glasses and ceramics for the immobilization of high-level nuclear waste and excess nuclear materials and discusses approaches to address new waste streams.

  15. EAP high-level product architecture

    NASA Astrophysics Data System (ADS)

    Gudlaugsson, T. V.; Mortensen, N. H.; Sarban, R.

    2013-04-01

    EAP technology has the potential to be used in a wide range of applications. This poses the challenge to the EAP component manufacturers to develop components for a wide variety of products. Danfoss Polypower A/S is developing an EAP technology platform, which can form the basis for a variety 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 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 has resulted in the first version of an EAP technology platform, on which multiple EAP products can be based. The contents of the platform have been the result of multi-disciplinary development work at Danfoss PolyPower, as well as collaboration with potential customers and research institutions. Initial results from applying the platform on demonstrator design for potential applications are promising. The scope of the article does not include technical details.

  16. The effects of high level infrasound

    SciTech Connect

    Johnson, D.L.

    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 concerned mainly about hearing, some discussion of other physiological effects is appropriate. Such discussion also serves to highlight a basic question, 'Is hearing the main concern of infrasound and low frequency exposure, or is there a more sensitive mechanism'. It would be comforting to know that the focal point of this conference is indeed the most important concern. Therefore, besides hearing loss and auditory threshold of infrasonic and low frequency exposure, four other effects will be provided. These are performance, respiration, annoyance, and vibration.

  17. Service Oriented Architecture for High Level Applications

    SciTech Connect

    Chu, Chungming; Chevtsov, Sergei; Wu, Juhao; Shen, Guobao; /Brookhaven

    2012-06-28

    Standalone high level applications often suffer from poor performance and reliability due to lengthy initialization, heavy computation and rapid graphical update. Service-oriented architecture (SOA) is trying to separate the initialization and computation from applications and to distribute such work to various service providers. Heavy computation such as beam tracking will be done periodically on a dedicated server and data will be available to client applications at all time. Industrial standard service architecture can help to improve the performance, reliability and maintainability of the service. Robustness will also be improved by reducing the complexity of individual client applications.

  18. Technetium Chemistry in High-Level Waste

    SciTech Connect

    Hess, Nancy J.

    2006-06-01

    Tc contamination is found within the DOE complex at those sites whose mission involved extraction of plutonium from irradiated uranium fuel or isotopic enrichment of uranium. At the Hanford Site, chemical separations and extraction processes generated large amounts of high level and transuranic wastes that are currently stored in underground tanks. The waste from these extraction processes is currently stored in underground High Level Waste (HLW) tanks. However, the chemistry of the HLW in any given tank is greatly complicated by repeated efforts to reduce volume and recover isotopes. These processes ultimately resulted in mixing of waste streams from different processes. As a result, the chemistry and the fate of Tc in HLW tanks are not well understood. This lack of understanding has been made evident in the failed efforts to leach Tc from sludge and to remove Tc from supernatants prior to immobilization. Although recent interest in Tc chemistry has shifted from pretreatment chemistry to waste residuals, both needs are served by a fundamental understanding of Tc chemistry.

  19. High level intelligent control of telerobotics systems

    NASA Technical Reports Server (NTRS)

    Mckee, James

    1988-01-01

    A high level robot command language is proposed for the autonomous mode of an advanced telerobotics system and a predictive display mechanism for the teleoperational model. It is believed that any such system will involve some mixture of these two modes, since, although artificial intelligence can facilitate significant autonomy, a system that can resort to teleoperation will always have the advantage. The high level command language will allow humans to give the robot instructions in a very natural manner. The robot will then analyze these instructions to infer meaning so that is can translate the task into lower level executable primitives. If, however, the robot is unable to perform the task autonomously, it will switch to the teleoperational mode. The time delay between control movement and actual robot movement has always been a problem in teleoperations. The remote operator may not actually see (via a monitor) the results of high actions for several seconds. A computer generated predictive display system is proposed whereby the operator can see a real-time model of the robot's environment and the delayed video picture on the monitor at the same time.

  20. High-level waste: View from Nevada

    SciTech Connect

    Miller, B.

    1994-12-31

    {open_quotes}Instead of acknowledging the serious shortcomings of the current waste program, the Department of Energy (DOE) has sought to tighten the screws on Nevada,{close_quotes} says Nevada Governor Bob Miller. Nevada`s opposition to the federal government`s proposed high-level radioactive waste repository at Yucca Mountain has grown out of fundamental flaws within the siting process, says Miller. {open_quotes}This process has left the nation with one technically flawed site as its sole prospect for nuclear waste disposal,{close_quotes} he says. Miller claims that DOE has acknowledged that the site is inadequate. Nevertheless, he says, the agency has insisted on pressing ahead with its plans, attempting to {open_quotes}adjust the standards to fit the site.{close_quotes} Miller concludes that dry and/or above-ground waste storage at reactor site represents a more sensible - and less costly - disposal method for high-level wastes, at least in the short term.

  1. Commissioning of the CMS High Level Trigger

    SciTech Connect

    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.

  2. Hot-wall corrosion testing of simulated high level nuclear waste

    SciTech Connect

    Chandler, G.T.; Zapp, P.E.; Mickalonis, J.I.

    1995-01-01

    Three materials of construction for steam tubes used in the evaporation of high level radioactive waste were tested under heat flux conditions, referred to as hot-wall tests. The materials were type 304L stainless steel alloy C276, and alloy G3. Non-radioactive acidic and alkaline salt solutions containing halides and mercury simulated different high level waste solutions stored or processed at the United States Department of Energy`s Savannah River Site. Alloy C276 was also tested for corrosion susceptibility under steady-state conditions. The nickel-based alloys C276 and G3 exhibited excellent corrosion resistance under the conditions studied. Alloy C276 was not susceptible to localized corrosion and had a corrosion rate of 0.01 mpy (0.25 {mu}m/y) when exposed to acidic waste sludge and precipitate slurry at a hot-wall temperature of 150{degrees}C. Type 304L was susceptible to localized corrosion under the same conditions. Alloy G3 had a corrosion rate of 0.1 mpy (2.5 {mu}m/y) when exposed to caustic high level waste evaporator solution at a hot-wall temperature of 220{degrees}C compared to 1.1 mpy (28.0 {mu}/y) for type 304L. Under extreme caustic conditions (45 weight percent sodium hydroxide) G3 had a corrosion rate of 0.1 mpy (2.5 {mu}m/y) at a hot-wall temperature of 180{degrees}C while type 304L had a high corrosion rate of 69.4 mpy (1.8 mm/y).

  3. New Rice for Africa (NERICA) cultivars exhibit different levels of post-attachment resistance against the parasitic weeds Striga hermonthica and Striga asiatica.

    PubMed

    Cissoko, Mamadou; Boisnard, Arnaud; Rodenburg, Jonne; Press, Malcolm C; Scholes, Julie D

    2011-12-01

    Striga hermonthica and S. asiatica are root parasitic weeds that infect the major cereal crops of sub-Saharan Africa causing severe losses in yield. The interspecific upland NEw RICe for Africa (NERICA) cultivars are popular amongst subsistence farmers, but little is known about their post-attachment resistance against Striga. Here, we evaluate the post-attachment resistance levels of the NERICA cultivars and their parents against ecotypes of S. hermonthica and S.asiatica, characterize the phenotype of the resistance mechanisms and determine the effect of Striga on host biomass. Some NERICA cultivars showed good broad-spectrum resistance against several Striga ecotypes, whereas others showed intermediate resistance or were very susceptible. The phenotype of a resistant interaction was often characterized by an inability of the parasite to penetrate the endodermis. Moreover, some parasites formed only a few connections to the host xylem, grew slowly and remained small. The most resistant NERICA cultivars were least damaged by Striga, although even a small number of parasites caused a reduction in above-ground host biomass. The elucidation of the molecular genetic basis of the resistance mechanisms and tolerance would allow the development of cultivars with multiple, durable resistance for use in farmers' fields.

  4. High-level connectionist models. Semiannual report

    SciTech Connect

    Pollack, J.B.

    1989-08-01

    The major achievement of this semiannum was the significant revision and extension of the Recursive Auto-Associative Memory (RAAM) work for publication in the journal Artificial Intelligence. Included as an appendix to this report, the article includes several new elements: (1) Background - The work was more clearly set into the area of recursive distributed representations, machine learning, and the adequacy of the connectionist approach for high-level cognitive modeling; (2) New Experiment - RAAM was applied to finding compact representations for sequences of letters; (3) Analysis - The developed representations were analyzed as features which range from categorical to distinctive. Categorical features distinguish between conceptual categories while distinctive features vary within categories and discriminate or label the members. The representations were also analyzed geometrically; and (4) Applications - Feasibility studies were performed and described on inference by association, and on using RAAM-generated patterns along with cascaded networks for natural language parsing. Both of these remain long-term goals of the project.

  5. The High Level Data Reduction Library

    NASA Astrophysics Data System (ADS)

    Ballester, P.; Gabasch, A.; Jung, Y.; Modigliani, A.; Taylor, J.; Coccato, L.; Freudling, W.; Neeser, M.; Marchetti, E.

    2015-09-01

    The European Southern Observatory (ESO) provides pipelines to reduce data for most of the instruments at its Very Large telescope (VLT). These pipelines are written as part of the development of VLT instruments, and are used both in the ESO's operational environment and by science users who receive VLT data. All the pipelines are highly specific geared toward instruments. However, experience showed that the independently developed pipelines include significant overlap, duplication and slight variations of similar algorithms. In order to reduce the cost of development, verification and maintenance of ESO pipelines, and at the same time improve the scientific quality of pipelines data products, ESO decided to develop a limited set of versatile high-level scientific functions that are to be used in all future pipelines. The routines are provided by the High-level Data Reduction Library (HDRL). To reach this goal, we first compare several candidate algorithms and verify them during a prototype phase using data sets from several instruments. Once the best algorithm and error model have been chosen, we start a design and implementation phase. The coding of HDRL is done in plain C and using the Common Pipeline Library (CPL) functionality. HDRL adopts consistent function naming conventions and a well defined API to minimise future maintenance costs, implements error propagation, uses pixel quality information, employs OpenMP to take advantage of multi-core processors, and is verified with extensive unit and regression tests. This poster describes the status of the project and the lesson learned during the development of reusable code implementing algorithms of high scientific quality.

  6. Decontamination of high-level waste canisters

    SciTech Connect

    Nesbitt, J.F.; Slate, S.C.; Fetrow, L.K.

    1980-12-01

    This report presents evaluations of several methods for the in-process decontamination of metallic canisters containing any one of a number of solidified high-level waste (HLW) forms. The use of steam-water, steam, abrasive blasting, electropolishing, liquid honing, vibratory finishing and soaking have been tested or evaluated as potential techniques to decontaminate the outer surfaces of HLW canisters. Either these techniques have been tested or available literature has been examined to assess their applicability to the decontamination of HLW canisters. Electropolishing has been found to be the most thorough method to remove radionuclides and other foreign material that may be deposited on or in the outer surface of a canister during any of the HLW processes. Steam or steam-water spraying techniques may be adequate for some applications but fail to remove all contaminated forms that could be present in some of the HLW processes. Liquid honing and abrasive blasting remove contamination and foreign material very quickly and effectively from small areas and components although these blasting techniques tend to disperse the material removed from the cleaned surfaces. Vibratory finishing is very capable of removing the bulk of contamination and foreign matter from a variety of materials. However, special vibratory finishing equipment would have to be designed and adapted for a remote process. Soaking techniques take long periods of time and may not remove all of the smearable contamination. If soaking involves pickling baths that use corrosive agents, these agents may cause erosion of grain boundaries that results in rough surfaces.

  7. Performance of the CMS High Level Trigger

    NASA Astrophysics Data System (ADS)

    Perrotta, Andrea

    2015-12-01

    The CMS experiment has been designed with a 2-level trigger system. The first level is implemented using custom-designed electronics. The second level is the so-called High Level Trigger (HLT), a streamlined version of the CMS offline reconstruction software running on a computer farm. For Run II of the Large Hadron Collider, the increases in center-of-mass energy and luminosity will raise the event rate to a level challenging for the HLT algorithms. The increase in the number of interactions per bunch crossing, on average 25 in 2012, and expected to be around 40 in Run II, will be an additional complication. We present here the expected performance of the main triggers that will be used during the 2015 data taking campaign, paying particular attention to the new approaches that have been developed to cope with the challenges of the new run. This includes improvements in HLT electron and photon reconstruction as well as better performing muon triggers. We will also present the performance of the improved tracking and vertexing algorithms, discussing their impact on the b-tagging performance as well as on the jet and missing energy reconstruction.

  8. HIGH LEVEL RF FOR THE SNS RING.

    SciTech Connect

    ZALTSMAN,A.; BLASKIEWICZ,M.; BRENNAN,J.; BRODOWSKI,J.; METH,M.; SPITZ,R.; SEVERINO,F.

    2002-06-03

    A high level RF system (HLRF) consisting of power amplifiers (PA's) and ferrite loaded cavities is being designed and built by Brookhaven National Laboratory (BNL) for the Spallation Neutron Source (SNS) project. It is a fixed frequency, two harmonic system whose main function is to maintain a gap for the kicker rise time. Three cavities running at the fundamental harmonic (h=l) will provide 40 kV and one cavity at the second harmonic (h=2) will provide 20 kV. Each cavity has two gaps with a design voltage of 10 kV per gap and will be driven by a power amplifier (PA) directly adjacent to it. The PA uses a 600kW tetrode to provide the necessary drive current. The anode of the tetrode is magnetically coupled to the downstream cell of the cavity. Drive to the PA will be provided by a wide band, solid state amplifier located remotely. A dynamic tuning scheme will be implemented to help compensate for the effect of beam loading.

  9. CMS High Level Trigger Timing Measurements

    NASA Astrophysics Data System (ADS)

    Richardson, Clint

    2015-12-01

    The two-level trigger system employed by CMS consists of the Level 1 (L1) Trigger, which is implemented using custom-built electronics, and the High Level Trigger (HLT), a farm of commercial CPUs running a streamlined version of the offline CMS reconstruction software. The operational L1 output rate of 100 kHz, together with the number of CPUs in the HLT farm, imposes a fundamental constraint on the amount of time available for the HLT to process events. Exceeding this limit impacts the experiment's ability to collect data efficiently. Hence, there is a critical need to characterize the performance of the HLT farm as well as the algorithms run prior to start up in order to ensure optimal data taking. Additional complications arise from the fact that the HLT farm consists of multiple generations of hardware and there can be subtleties in machine performance. We present our methods of measuring the timing performance of the CMS HLT, including the challenges of making such measurements. Results for the performance of various Intel Xeon architectures from 2009-2014 and different data taking scenarios are also presented.

  10. DEFENSE HIGH LEVEL WASTE GLASS DEGRADATION

    SciTech Connect

    W. Ebert

    2001-09-20

    The purpose of this Analysis/Model Report (AMR) is to document the analyses that were done to develop models for radionuclide release from high-level waste (HLW) glass dissolution that can be integrated into performance assessment (PA) calculations conducted to support site recommendation and license application for the Yucca Mountain site. This report was developed in accordance with the ''Technical Work Plan for Waste Form Degradation Process Model Report for SR'' (CRWMS M&O 2000a). It specifically addresses the item, ''Defense High Level Waste Glass Degradation'', of the product technical work plan. The AP-3.15Q Attachment 1 screening criteria determines the importance for its intended use of the HLW glass model derived herein to be in the category ''Other Factors for the Postclosure Safety Case-Waste Form Performance'', and thus indicates that this factor does not contribute significantly to the postclosure safety strategy. Because the release of radionuclides from the glass will depend on the prior dissolution of the glass, the dissolution rate of the glass imposes an upper bound on the radionuclide release rate. The approach taken to provide a bound for the radionuclide release is to develop models that can be used to calculate the dissolution rate of waste glass when contacted by water in the disposal site. The release rate of a particular radionuclide can then be calculated by multiplying the glass dissolution rate by the mass fraction of that radionuclide in the glass and by the surface area of glass contacted by water. The scope includes consideration of the three modes by which water may contact waste glass in the disposal system: contact by humid air, dripping water, and immersion. The models for glass dissolution under these contact modes are all based on the rate expression for aqueous dissolution of borosilicate glasses. The mechanism and rate expression for aqueous dissolution are adequately understood; the analyses in this AMR were conducted to

  11. Dolutegravir (S/GSK1349572) exhibits significantly slower dissociation than raltegravir and elvitegravir from wild-type and integrase inhibitor-resistant HIV-1 integrase-DNA complexes.

    PubMed

    Hightower, Kendra E; Wang, Ruolan; Deanda, Felix; Johns, Brian A; Weaver, Kurt; Shen, Yingnian; Tomberlin, Ginger H; Carter, H Luke; Broderick, Timothy; Sigethy, Scott; Seki, Takahiro; Kobayashi, Masanori; Underwood, Mark R

    2011-10-01

    The integrase inhibitor (INI) dolutegravir (DTG; S/GSK1349572) has significant activity against HIV-1 isolates with raltegravir (RAL)- and elvitegravir (ELV)-associated resistance mutations. As an initial step in characterizing the different resistance profiles of DTG, RAL, and ELV, we determined the dissociation rates of these INIs with integrase (IN)-DNA complexes containing a broad panel of IN proteins, including IN substitutions corresponding to signature RAL and ELV resistance mutations. DTG dissociates slowly from a wild-type IN-DNA complex at 37°C with an off-rate of 2.7 × 10(-6) s(-1) and a dissociative half-life (t(1/2)) of 71 h, significantly longer than the half-lives for RAL (8.8 h) and ELV (2.7 h). Prolonged binding (t(1/2), at least 5 h) was observed for DTG with IN-DNA complexes containing E92, Y143, Q148, and N155 substitutions. The addition of a second substitution to either Q148 or N155 typically resulted in an increase in the off-rate compared to that with the single substitution. For all of the IN substitutions tested, the off-rate of DTG from IN-DNA complexes was significantly slower (from 5 to 40 times slower) than the off-rate of RAL or ELV. These data are consistent with the potential for DTG to have a higher genetic barrier to resistance, provide evidence that the INI off-rate may be an important component of the mechanism of INI resistance, and suggest that the slow dissociation of DTG may contribute to its distinctive resistance profile.

  12. Transgenic soybean overexpressing GmSamT1 exhibits resistance to multiple-HG types of soybean cysts nematode heterodera glycines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean (Glycine max (L.) Merr.) salicylic acid methyl transferase (GmSAMT1) catalyzes the conversion of salicylic acid to methyl salicylate. Prior results showed that when GmSAMT1 was overexpressed in transgenic soybean hairy roots, resistance is conferred against soybean cyst nematode (SCN), Heter...

  13. In Vitro Recombinants of Antibiotic-Resistant Chlamydia trachomatis Strains Have Statistically More Breakpoints than Clinical Recombinants for the Same Sequenced Loci and Exhibit Selection at Unexpected Loci

    PubMed Central

    Srinivasan, Tara; Bruno, William J.; Wan, Raymond; Yen, Albert; Duong, Jennifer

    2012-01-01

    Lateral gene transfer (LGT) is essential for generating between-strain genomic recombinants of Chlamydia trachomatis to facilitate the organism's evolution. Because there is no reliable laboratory-based gene transfer system for C. trachomatis, in vitro generation of recombinants from antibiotic-resistant strains is being used to study LGT. However, selection pressures imposed on in vitro recombinants likely affect statistical properties of recombination relative to naturally occurring clinical recombinants, including prevalence at particular loci. We examined multiple loci for 16 in vitro-derived recombinants of ofloxacin- and rifampin-resistant L1 and D strains, respectively, grown with both antibiotics, and compared these with the same sequenced loci among 11 clinical recombinants. Breakpoints and recombination frequency were examined using phylogenetics, bioinformatics, and statistics. In vitro and clinical isolates clustered perfectly into two groups, without misclassification, using Ward's minimum variance based on breakpoint data. As expected, gyrA (confers ofloxacin resistance) and rpoB (confers rifampin resistance) had significantly more breakpoints among in vitro recombinants than among clinical recombinants (P < 0.0001 and P = 0.02, respectively, using the Wilcoxon rank sum test). Unexpectedly, trpA also had significantly more breakpoints for in vitro recombinants (P < 0.0001). There was also significant selection at other loci. The strongest bias was for ompA in strain D (P = 3.3 × 10−8). Our results indicate that the in vitro model differs statistically from natural recombination events. Additional genomic studies are needed to determine the factors responsible for the observed selection biases at unexpected loci and whether these are important for LGT to inform approaches for genetically manipulating C. trachomatis. PMID:22123249

  14. Arabidopsis Auxin Mutants Are Compromised in Systemic Acquired Resistance and Exhibit Aberrant Accumulation of Various Indolic Compounds1[W][OA

    PubMed Central

    Truman, William M.; Bennett, Mark H.; Turnbull, Colin G.N.; Grant, Murray R.

    2010-01-01

    Systemic acquired resistance is a widespread phenomenon in the plant kingdom that confers heightened and often enduring immunity to a range of diverse pathogens. Systemic immunity develops through activation of plant disease resistance protein signaling networks following local infection with an incompatible pathogen. The accumulation of the phytohormone salicylic acid in systemically responding tissues occurs within days after a local immunizing infection and is essential for systemic resistance. However, our knowledge of the signaling components underpinning signal perception and the establishment of systemic immunity are rudimentary. Previously, we showed that an early and transient increase in jasmonic acid in distal responding tissues was central to effective establishment of systemic immunity. Based upon predicted transcriptional networks induced in naive Arabidopsis (Arabidopsis thaliana) leaves following avirulent Pseudomonas syringae challenge, we show that a variety of auxin mutants compromise the establishment of systemic immunity. Linking together transcriptional and targeted metabolite studies, our data provide compelling evidence for a role of indole-derived compounds, but not auxin itself, in the establishment and maintenance of systemic immunity. PMID:20081042

  15. Characterization of Klebsiella sp. strain 10982, a colonizer of humans that contains novel antibiotic resistance alleles and exhibits genetic similarities to plant and clinical Klebsiella isolates.

    PubMed

    Hazen, Tracy H; Zhao, LiCheng; Sahl, Jason W; Robinson, Gwen; Harris, Anthony D; Rasko, David A; Johnson, J Kristie

    2014-01-01

    A unique Klebsiella species strain, 10982, was cultured from a perianal swab specimen obtained from a patient in the University of Maryland Medical Center intensive care unit. Klebsiella sp. 10982 possesses a large IncA/C multidrug resistance plasmid encoding a novel FOX AmpC β-lactamase designated FOX-10. A novel variant of the LEN β-lactamase was also identified. Genome sequencing and bioinformatic analysis demonstrated that this isolate contains genes associated with nitrogen fixation, allantoin metabolism, and citrate fermentation. These three gene regions are typically present in either Klebsiella pneumoniae clinical isolates or Klebsiella nitrogen-fixing endophytes but usually not in the same organism. Phylogenomic analysis of Klebsiella sp. 10982 and sequenced Klebsiella genomes demonstrated that Klebsiella sp. 10982 is present on a branch that is located intermediate between the genomes of nitrogen-fixing endophytes and K. pneumoniae clinical isolates. Metabolic features identified in the genome of Klebsiella sp. 10982 distinguish this isolate from other Klebsiella clinical isolates. These features include the nitrogen fixation (nif) gene cluster, which is typically present in endophytic Klebsiella isolates and is absent from Klebsiella clinical isolates. Additionally, the Klebsiella sp. 10982 genome contains genes associated with allantoin metabolism, which have been detected primarily in K. pneumoniae isolates from liver abscesses. Comparative genomic analysis of Klebsiella sp. 10982 demonstrated that this organism has acquired genes conferring new metabolic strategies and novel antibiotic resistance alleles, both of which may enhance its ability to colonize the human body.

  16. Penetration barrier contributes to bacterial biofilm-associated resistance against only select antibiotics, and exhibits genus-, strain- and antibiotic-specific differences.

    PubMed

    Singh, Rachna; Sahore, Simmi; Kaur, Preetinder; Rani, Alka; Ray, Pallab

    2016-08-01

    Bacterial biofilms are implicated in a wide range of implant-based and chronic infections. These infections are often associated with adverse therapeutic outcomes, owing to the decreased antibiotic susceptibility of biofilms compared with their planktonic counterparts. This altered biofilm susceptibility has been attributed to multiple factors, including a reduced antibiotic penetration. Although several studies have addressed the role of penetration barrier in biofilm-associated drug resistance, it remains inconclusive. This study was done to elucidate antibiotic penetration through biofilms formed by Staphylococcus aureus, S. epidermidis, Escherichia coli and Klebsiella pneumoniae, using an agar disk diffusion assay. Penetration capacity of six antimicrobial drugs from different classes (β-lactams, aminoglycosides, tetracyclines, phenicols, fluoroquinolones and glycopeptides) through biofilms formed by standard strains and clinical isolates from catheter-related bloodstream infections (CRBSI) was elucidated by measuring their growth-inhibition zones in lawn cultures on Mueller-Hinton agar, following diffusion of an antibiotic from an overlying disk through their biofilm to the agar medium. Penetration of only select antimicrobials (vancomycin and chloramphenicol) was hindered through biofilms. There was considerable variation in biofilm-permeating capacity depending upon the genus, strain/CRBSI isolate and antibiotic tested. Furthermore, antibiotics failed to kill the biofilm cells independent of penetration, indicating that other factors contributed substantially to biofilm resistance.

  17. Penetration barrier contributes to bacterial biofilm-associated resistance against only select antibiotics, and exhibits genus-, strain- and antibiotic-specific differences.

    PubMed

    Singh, Rachna; Sahore, Simmi; Kaur, Preetinder; Rani, Alka; Ray, Pallab

    2016-08-01

    Bacterial biofilms are implicated in a wide range of implant-based and chronic infections. These infections are often associated with adverse therapeutic outcomes, owing to the decreased antibiotic susceptibility of biofilms compared with their planktonic counterparts. This altered biofilm susceptibility has been attributed to multiple factors, including a reduced antibiotic penetration. Although several studies have addressed the role of penetration barrier in biofilm-associated drug resistance, it remains inconclusive. This study was done to elucidate antibiotic penetration through biofilms formed by Staphylococcus aureus, S. epidermidis, Escherichia coli and Klebsiella pneumoniae, using an agar disk diffusion assay. Penetration capacity of six antimicrobial drugs from different classes (β-lactams, aminoglycosides, tetracyclines, phenicols, fluoroquinolones and glycopeptides) through biofilms formed by standard strains and clinical isolates from catheter-related bloodstream infections (CRBSI) was elucidated by measuring their growth-inhibition zones in lawn cultures on Mueller-Hinton agar, following diffusion of an antibiotic from an overlying disk through their biofilm to the agar medium. Penetration of only select antimicrobials (vancomycin and chloramphenicol) was hindered through biofilms. There was considerable variation in biofilm-permeating capacity depending upon the genus, strain/CRBSI isolate and antibiotic tested. Furthermore, antibiotics failed to kill the biofilm cells independent of penetration, indicating that other factors contributed substantially to biofilm resistance. PMID:27402781

  18. Phenotypic- and Genotypic-Resistance Detection for Adaptive Resistance Management in Tetranychus urticae Koch

    PubMed Central

    Kwon, Deok Ho; Kang, Taek-Jun; Kim, Young Ho; Lee, Si Hyeock

    2015-01-01

    Rapid resistance detection is necessary for the adaptive management of acaricide-resistant populations of Tetranychus urticae. Detection of phenotypic and genotypic resistance was conducted by employing residual contact vial bioassay (RCV) and quantitative sequencing (QS) methods, respectively. RCV was useful for detecting the acaricide resistance levels of T. urticae, particularly for on-site resistance detection; however, it was only applicable for rapid-acting acaricides (12 out of 19 tested acaricides). QS was effective for determining the frequencies of resistance alleles on a population basis, which corresponded to 12 nonsynonymous point mutations associated with target-site resistance to five types of acaricides [organophosphates (monocrotophos, pirimiphos-methyl, dimethoate and chlorpyrifos), pyrethroids (fenpropathrin and bifenthrin), abamectin, bifenazate and etoxazole]. Most field-collected mites exhibited high levels of multiple resistance, as determined by RCV and QS data, suggesting the seriousness of their current acaricide resistance status in rose cultivation areas in Korea. The correlation analyses revealed moderate to high levels of positive relationships between the resistance allele frequencies and the actual resistance levels in only five of the acaricides evaluated, which limits the general application of allele frequency as a direct indicator for estimating actual resistance levels. Nevertheless, the resistance allele frequency data alone allowed for the evaluation of the genetic resistance potential and background of test mite populations. The combined use of RCV and QS provides basic information on resistance levels, which is essential for choosing appropriate acaricides for the management of resistant T. urticae. PMID:26545209

  19. Transgenic Pearl Millet Male Fertility Restorer Line (ICMP451) and Hybrid (ICMH451) Expressing Brassica juncea Nonexpressor of Pathogenesis Related Genes 1 (BjNPR1) Exhibit Resistance to Downy Mildew Disease

    PubMed Central

    Khareedu, Venkateswara Rao; Vudem, Dashavantha Reddy

    2014-01-01

    Brassica juncea Nonexpressor of pathogenesis-related genes 1 (BjNPR1) has been introduced into pearl millet male fertility restorer line ICMP451 by Agrobacterium tumefaciens-mediated genetic transformation. Transgenic pearl millet plants were regenerated from the phosphinothricin-resistant calli obtained after co-cultivation with A. tumefaciens strain LBA4404 harbouring Ti plasmid pSB111-bar-BjNPR1. Molecular analyses confirmed the stable integration and expression of BjNPR1 in transgenic pearl millet lines. Transgenes BjNPR1 and bar were stably inherited and disclosed co-segregation in subsequent generations in a Mendelian fashion. Transgenic pearl millet hybrid ICMH451-BjNPR1 was developed by crossing male-sterile line 81A X homozygous transgenic line ICMP451-BjNPR1. T3 and T4 homozygous lines of ICMP451-BjNPR1 and hybrid ICMH451-BjNPR1 exhibited resistance to three strains of downy mildew pathogen, while the untransformed ICMP451 and the isogenic hybrid ICMH451 plants were found susceptible. Following infection with S. graminicola, differential expression of systemic acquired resistance pathway genes, UDP-glucose salicylic acid glucosyl transferase and pathogenesis related gene 1 was observed in transgenic ICMP451-BjNPR1 and untransformed plants indicating the activation of systemic acquired resistance pathway contributing to the transgene-mediated resistance against downy mildew. The transgenic pearl millet expressing BjNPR1 showed resistance to multiple strains of S. graminicola and, as such, seems promising for the development of durable downy mildew resistant hybrids. PMID:24603762

  20. High-level waste-form-product performance evaluation. [Leaching; waste loading; mechanical stability

    SciTech Connect

    Bernadzikowski, T A; Allender, J S; Stone, J A; Gordon, D E; Gould, Jr, T H; Westberry, III, C F

    1982-01-01

    Seven candidate waste forms were evaluated for immobilization and geologic disposal of high-level radioactive wastes. The waste forms were compared on the basis of leach resistance, mechanical stability, and waste loading. All forms performed well at leaching temperatures of 40, 90, and 150/sup 0/C. Ceramic forms ranked highest, followed by glasses, a metal matrix form, and concrete. 11 tables.

  1. Plastid-expressed 5-enolpyruvylshikimate-3-phosphate synthase genes provide high level glyphosate tolerance in tobacco.

    PubMed

    Ye, G N; Hajdukiewicz, P T; Broyles, D; Rodriguez, D; Xu, C W; Nehra, N; Staub, J M

    2001-02-01

    Plastid transformation (transplastomic) technology has several potential advantages for biotechnological applications including the use of unmodified prokaryotic genes for engineering, potential high-level gene expression and gene containment due to maternal inheritance in most crop plants. However, the efficacy of a plastid-encoded trait may change depending on plastid number and tissue type. We report a feasibility study in tobacco plastids to achieve high-level herbicide resistance in both vegetative tissues and reproductive organs. We chose to test glyphosate resistance via over-expression in plastids of tolerant forms of 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS). Immunological, enzymatic and whole-plant assays were used to prove the efficacy of three different prokaryotic (Achromobacter, Agrobacterium and Bacillus) EPSPS genes. Using the Agrobacterium strain CP4 EPSPS as a model we identified translational control sequences that direct a 10,000-fold range of protein accumulation (to >10% total soluble protein in leaves). Plastid-expressed EPSPS could provide very high levels of glyphosate resistance, although levels of resistance in vegetative and reproductive tissues differed depending on EPSPS accumulation levels, and correlated to the plastid abundance in these tissues. Paradoxically, higher levels of plastid-expressed EPSPS protein accumulation were apparently required for efficacy than from a similar nuclear-encoded gene. Nevertheless, the demonstration of high-level glyphosate tolerance in vegetative and reproductive organs using transplastomic technology provides a necessary step for transfer of this technology to other crop species.

  2. Characterization of a compensatory mutant of Leishmania major that lacks ether lipids but exhibits normal growth, and G418 and hygromycin resistance.

    PubMed

    Zufferey, Rachel; Bibis, Stergios S; Zhu, Tongtong; Dhalladoo, Subbhalakshmi

    2012-03-01

    Ether glycerolipid biosynthesis in Leishmania major initiates with the acylation of dihydroxyacetonephosphate by the glycosomal dihydroxyacetonephosphate acyltransferase LmDAT. We previously reported that a null mutant of LmDAT is severely affected in logarithmic growth, survival during stationary phase, and in virulence in mice. In addition, it lacks all ether glycerolipids, produces altered forms of the ether-lipid based virulence factors lipophosphoglycan and increased levels of GPI-anchored protein gp63. Here, we describe the characterization of a compensatory mutant of a null strain of LmDAT, Δlmdat/Δlmdat(rev). Similarly to the null mutant, the Δlmdat/Δlmdat(rev) strain formed altered forms of lipophosphoglycan and increased levels of gp63, and was avirulent in mice infection. Further, dihydroxyacetonephosphate acyltransferase activity was absent in the revertant clone, indicating that a mutation in another acyltransferase gene did not confer dihydroxyacetonephosphate specificity. In contrast, the revertant grew normally but still exhibited poor survival during stationary phase. In addition, agarose gel analysis of its genomic DNA failed to detect any amplified DNA. Surprisingly, its sensitivity to aminoglycoside based antibiotics G418 and hygromycin was lower than that of the null mutant, wild type and complemented line. PMID:22306069

  3. Secretin receptor-knockout mice are resistant to high-fat diet-induced obesity and exhibit impaired intestinal lipid absorption.

    PubMed

    Sekar, Revathi; Chow, Billy K C

    2014-08-01

    Secretin, a classical gastrointestinal hormone released from S cells in response to acid and dietary lipid, regulates pleiotropic physiological functions, such as exocrine pancreatic secretion and gastric motility. Subsequent to recently proposed revisit on secretin's metabolic effects, we have confirmed lipolytic actions of secretin during starvation and discovered a hormone-sensitive lipase-mediated mechanistic pathway behind. In this study, a 12 wk high-fat diet (HFD) feeding to secretin receptor-knockout (SCTR(-/-)) mice and their wild-type (SCTR(+/+)) littermates revealed that, despite similar food intake, SCTR(-/-) mice gained significantly less weight (SCTR(+/+): 49.6±0.9 g; SCTR(-/-): 44.7±1.4 g; P<0.05) and exhibited lower body fat content. These SCTR(-/-) mice have corresponding alleviated HFD-associated hyperleptinemia and improved glucose/insulin tolerance. Further analyses indicate that SCTR(-/-) have impaired intestinal fatty acid absorption while having similar energy expenditure and locomotor activity. Reduced fat absorption in the intestine is further supported by lowered postprandial triglyceride concentrations in circulation in SCTR(-/-) mice. In jejunal cells, transcript and protein levels of a key fat absorption regulator, cluster of differentiation 36 (CD36), was reduced in knockout mice, while transcript of Cd36 and fatty-acid uptake in isolated enterocytes was stimulated by secretin. Based on our findings, a novel positive feedback pathway involving secretin and CD36 to enhance intestinal lipid absorption is being proposed.

  4. Characterization of a compensatory mutant of Leishmania major that lacks ether lipids but exhibits normal growth, and G418 and hygromycin resistance.

    PubMed

    Zufferey, Rachel; Bibis, Stergios S; Zhu, Tongtong; Dhalladoo, Subbhalakshmi

    2012-03-01

    Ether glycerolipid biosynthesis in Leishmania major initiates with the acylation of dihydroxyacetonephosphate by the glycosomal dihydroxyacetonephosphate acyltransferase LmDAT. We previously reported that a null mutant of LmDAT is severely affected in logarithmic growth, survival during stationary phase, and in virulence in mice. In addition, it lacks all ether glycerolipids, produces altered forms of the ether-lipid based virulence factors lipophosphoglycan and increased levels of GPI-anchored protein gp63. Here, we describe the characterization of a compensatory mutant of a null strain of LmDAT, Δlmdat/Δlmdat(rev). Similarly to the null mutant, the Δlmdat/Δlmdat(rev) strain formed altered forms of lipophosphoglycan and increased levels of gp63, and was avirulent in mice infection. Further, dihydroxyacetonephosphate acyltransferase activity was absent in the revertant clone, indicating that a mutation in another acyltransferase gene did not confer dihydroxyacetonephosphate specificity. In contrast, the revertant grew normally but still exhibited poor survival during stationary phase. In addition, agarose gel analysis of its genomic DNA failed to detect any amplified DNA. Surprisingly, its sensitivity to aminoglycoside based antibiotics G418 and hygromycin was lower than that of the null mutant, wild type and complemented line.

  5. Do Highly Effective Principals Also Have High Levels of Cultural Intelligence?

    ERIC Educational Resources Information Center

    Naughton, Whitney Michelle

    2010-01-01

    Purpose: The purpose of this study was to determine if elementary school principals who exhibit characteristics of highly effective principals also possess high levels of cultural intelligence. Methodology: Three instruments were used in this study, combining both qualitative and quantitative approaches to the collection of data. The first…

  6. Coping with naturally high levels of soil salinity and boron in the westside of central California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the Westside of central California, over 200,000 ha exhibit naturally high levels of salinity and boron (B). The Coast Ranges of the west central California evolved from complex folding and faulting of sedimentary and igneous rocks of Mesozoic and Tertiary age. Cretaceous and Tertiary marine sedi...

  7. Recessive resistance to Cucurbit yellow stunting disorder virus in melon TGR 1551

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cucurbit yellow stunting disorder virus (CYSDV) reduces melon (Cucumis melo L.) fruit quality and yield in many parts of the world. Host plant resistance of melon to CYSDV is a high priority for sustainable melon production in affected production areas. High-level resistance to CYSDV exhibited by TG...

  8. 46 CFR 153.409 - High level alarms.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false High level alarms. 153.409 Section 153.409 Shipping... BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Gauging Systems § 153.409 High level alarms. When Table 1 refers to this section or requires a cargo to have...

  9. 40 CFR 227.30 - High-level radioactive waste.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 26 2012-07-01 2011-07-01 true 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...

  10. 40 CFR 227.30 - High-level radioactive waste.

    Code of Federal Regulations, 2010 CFR

    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...

  11. 40 CFR 227.30 - High-level radioactive waste.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 25 2011-07-01 2011-07-01 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...

  12. 40 CFR 227.30 - High-level radioactive waste.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 25 2014-07-01 2014-07-01 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...

  13. 40 CFR 227.30 - High-level radioactive waste.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 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...

  14. Evaluation of high-level clouds in cloud resolving model simulations with ARM and KWAJEX observations

    NASA Astrophysics Data System (ADS)

    Liu, Zheng; Muhlbauer, Andreas; Ackerman, Thomas

    2015-12-01

    In this study, we evaluate high-level clouds in a cloud resolving model during two convective cases, ARM9707 and KWAJEX. The simulated joint histograms of cloud occurrence and radar reflectivity compare well with cloud radar and satellite observations when using a two-moment microphysics scheme. However, simulations performed with a single moment microphysical scheme exhibit low biases of approximately 20 dB. During convective events, two-moment microphysical overestimate the amount of high-level cloud and one-moment microphysics precipitate too readily and underestimate the amount and height of high-level cloud. For ARM9707, persistent large positive biases in high-level cloud are found, which are not sensitive to changes in ice particle fall velocity and ice nuclei number concentration in the two-moment microphysics. These biases are caused by biases in large-scale forcing and maintained by the periodic lateral boundary conditions. The combined effects include significant biases in high-level cloud amount, radiation, and high sensitivity of cloud amount to nudging time scale in both convective cases. The high sensitivity of high-level cloud amount to the thermodynamic nudging time scale suggests that thermodynamic nudging can be a powerful "tuning" parameter for the simulated cloud and radiation but should be applied with caution. The role of the periodic lateral boundary conditions in reinforcing the biases in cloud and radiation suggests that reducing the uncertainty in the large-scale forcing in high levels is important for similar convective cases and has far reaching implications for simulating high-level clouds in super-parameterized global climate models such as the multiscale modeling framework.

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

    SciTech Connect

    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).

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

    PubMed

    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. PMID:27070796

  17. Reference commercial high-level waste glass and canister definition.

    SciTech Connect

    Slate, S.C.; Ross, W.A.; Partain, W.L.

    1981-09-01

    This report presents technical data and performance characteristics of a high-level waste glass and canister intended for use in the design of a complete waste encapsulation package suitable for disposal in a geologic repository. The borosilicate glass contained in the stainless steel canister represents the probable type of high-level waste product that will be produced in a commercial nuclear-fuel reprocessing plant. Development history is summarized for high-level liquid waste compositions, waste glass composition and characteristics, and canister design. The decay histories of the fission products and actinides (plus daughters) calculated by the ORIGEN-II code are presented.

  18. Neptunium estimation in dissolver and high-level-waste solutions

    SciTech Connect

    Pathak, P.N.; Prabhu, D.R.; Kanekar, A.S.; Manchanda, V.K.

    2008-07-01

    This papers deals with the optimization of the experimental conditions for the estimation of {sup 237}Np in spent-fuel dissolver/high-level waste solutions using thenoyltrifluoroacetone as the extractant. (authors)

  19. Decision Document for Heat Removal from High Level Waste Tanks

    SciTech Connect

    WILLIS, W.L.

    2000-07-31

    This document establishes the combination of design and operational configurations that will be used to provide heat removal from high-level waste tanks during Phase 1 waste feed delivery to prevent the waste temperature from exceeding tank safety requirement limits. The chosen method--to use the primary and annulus ventilation systems to remove heat from the high-level waste tanks--is documented herein.

  20. High-Level Waste System Process Interface Description

    SciTech Connect

    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.

  1. High illness loads (physical and social) do not always force high levels of mass religiosity.

    PubMed

    Paul, Gregory S

    2012-04-01

    The hypothesis that high levels of religiosity are partly caused by high disease loads is in accord with studies showing that societal dysfunction promotes mass supernaturalism. However, some cultures suffering from high rates of disease and other socioeconomic dysfunction exhibit low levels of popular religiosity. At this point, it appears that religion is hard pressed to thrive in healthy societies, but poor conditions do not always make religion popular, either.

  2. Ethics on Exhibit

    ERIC Educational Resources Information Center

    Vick, Randy M.

    2011-01-01

    This article discusses ethical questions raised by an exhibition of work by an artist with a history of mental illness and the exhibition's relevance to art therapy and “outsider art” discourse on the subject. Considerations for how such an exhibit could be handled had the circumstances included an art therapist and art therapy client are…

  3. High level radioactive waste management facility design criteria

    SciTech Connect

    Sheikh, N.A.; Salaymeh, S.R.

    1993-10-01

    This paper discusses the engineering systems for the structural design of the Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS). At the DWPF, high level radioactive liquids will be mixed with glass particles and heated in a melter. This molten glass will then be poured into stainless steel canisters where it will harden. This process will transform the high level waste into a more stable, manageable substance. This paper discuss the structural design requirements for this unique one of a kind facility. A special emphasis will be concentrated on the design criteria pertaining to earthquake, wind and tornado, and flooding.

  4. Final report on cermet high-level waste forms

    SciTech Connect

    Kobisk, E.H.; Quinby, T.C.; Aaron, W.S.

    1981-08-01

    Cermets are being developed as an alternate method for the fixation of defense and commercial high level radioactive waste in a terminal disposal form. Following initial feasibility assessments of this waste form, consisting of ceramic particles dispersed in an iron-nickel base alloy, significantly improved processing methods were developed. The characterization of cermets has continued through property determinations on samples prepared by various methods from a variety of simulated and actual high-level wastes. This report describes the status of development of the cermet waste form as it has evolved since 1977. 6 tables, 18 figures.

  5. Disposal of high-level nuclear waste in space

    NASA Astrophysics Data System (ADS)

    Coopersmith, Jonathan

    1992-08-01

    A solution of launching high-level nuclear waste into space is suggested. Disposal in space includes solidifying the wastes, embedding them in an explosion-proof vehicle, and launching it into earth orbit, and then into a solar orbit. The benefits of such a system include not only the safe disposal of high-level waste but also the establishment of an infrastructure for large-scale space exploration and development. Particular attention is given to the wide range of technical choices along with the societal, economic, and political factors needed for success.

  6. Bilateral medial patellofemoral ligament reconstruction in high-level athletes.

    PubMed

    Kuroda, Yuichi; Matsushita, Takehiko; Matsumoto, Tomoyuki; Kawakami, Yohei; Kurosaka, Masahiro; Kuroda, Ryosuke

    2014-10-01

    This report presents two cases of high-level athletes with bilateral patellar dislocations who were able to return to their preinjury level of activity after bilateral medial patellofemoral ligament (MPFL) reconstruction, without any major complications. Patient 1 was a 19-year-old male volleyball player for a top-level college volleyball team, and patient 2 was a 24-year-old woman who was a member of a national-level adult softball team. MPFL reconstruction could be an effective treatment for bilateral patellar dislocation in high-level athletes. Level of evidence V.

  7. The Use of ARTEMIS with High-Level Applications

    SciTech Connect

    B. A. Bowling; H. Shoaee; S. Witherspoon

    1995-10-01

    ARTEMIS is an online accelerator modeling server developed at CEBAF. One of the design goals of ARTEMIS was to provide an integrated modeling environment for high- level accelerator diagnostic and control applications such as automated beam steering, Linac Energy management (LEM) and the fast feedback system. This report illustrates the use of ARTEMIS in these applications as well as the application interface using the EPICS cdev device support API. Concentration is placed on the design and implementation aspects of high- level applications which utilize the ARTEMIS server for information on beam dynamics. Performance benchmarks for various model operations provided by ARTEMIS are also discussed.

  8. A Teaching Aids Exhibition.

    ERIC Educational Resources Information Center

    Mahanja, Salah

    1985-01-01

    Describes an exhibition for the benefit of teachers of English in Arab Primary Schools, which was prepared by third-year students at the Teachers College for Arab Teachers. The exhibition included games, songs, audiovisual aids, crossword puzzles, vocabulary, spelling booklets, preposition aids, and worksheet and lesson planning aids. (SED)

  9. The ATLAS Data Acquisition and High Level Trigger system

    NASA Astrophysics Data System (ADS)

    The ATLAS TDAQ Collaboration

    2016-06-01

    This paper describes the data acquisition and high level trigger system of the ATLAS experiment at the Large Hadron Collider at CERN, as deployed during Run 1. Data flow as well as control, configuration and monitoring aspects are addressed. An overview of the functionality of the system and of its performance is presented and design choices are discussed.

  10. High-level manpower movement and Japan's foreign aid.

    PubMed

    Furuya, K

    1992-01-01

    "Japan's technical assistance programs to Asian countries are summarized. Movements of high-level manpower accompanying direct foreign investments by private enterprise are also reviewed. Proposals for increased human resources development include education and training of foreigners in Japan as well as the training of Japanese aid experts and the development of networks for information exchange."

  11. THE XAL INFRASTRUCTURE FOR HIGH LEVEL CONTROL ROOM APPLICATIONS

    SciTech Connect

    Shishlo, Andrei P; Allen, Christopher K; Chu, Paul; Galambos, John D; Pelaia II, Tom

    2009-01-01

    XAL is a Java programming framework for building high-level control applications related to accelerator physics. The structure, details of implementation, and interaction between components, auxiliary XAL packages, and the latest modifications are discussed. A general overview of XAL applications created for the SNS project is presented.

  12. 46 CFR 153.409 - High level alarms.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... LEVEL ALARM.” Cargo Temperature Control Systems ... 46 Shipping 5 2011-10-01 2011-10-01 false High level alarms. 153.409 Section 153.409 Shipping... BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo...

  13. 46 CFR 153.409 - High level alarms.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... LEVEL ALARM.” Cargo Temperature Control Systems ... 46 Shipping 5 2012-10-01 2012-10-01 false High level alarms. 153.409 Section 153.409 Shipping... BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo...

  14. Susceptibility of Drug-Resistant Clinical Herpes Simplex Virus Type 1 Strains to Essential Oils of Ginger, Thyme, Hyssop, and Sandalwood▿

    PubMed Central

    Schnitzler, Paul; Koch, Christine; Reichling, Jürgen

    2007-01-01

    Acyclovir-resistant clinical isolates of herpes simplex virus type 1 (HSV-1) were analyzed in vitro for their susceptibilities to essential oils of ginger, thyme, hyssop, and sandalwood. All essential oils exhibited high levels of virucidal activity against acyclovir-sensitive strain KOS and acyclovir-resistant HSV-1 clinical isolates and reduced plaque formation significantly. PMID:17353250

  15. Phytophthora fruit rot-resistant watermelon germplasm lines: USVL489-PFR, USVL782-PFR, USVL203-PFR, and USVL020-PFR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    USVL489-PFR, USVL782-PFR, USVL203-PFR, and USVL020-PFR are watermelon (Citrullus lanatus var. lanatus (Thunb.) Matsum. & Nakai) germplasm lines that exhibit high levels of resistance to Phytophthora fruit rot caused by the plant pathogen Phytophthora capsici. Resistance in these germplasm lines is ...

  16. Communicating Science through Exhibitions

    NASA Astrophysics Data System (ADS)

    Dusenbery, P.; Harold, J.; Morrow, C.

    It is critically important for the public to better understand the scientific process. Museum exhibitions are an important part of informal science education that can effectively reach public audiences as well as school groups. They provide an important gateway for the public to learn about compelling scientific endeavors. There are many ways for scientists to help develop science exhibitions. The Space Science Institute (SSI) is a national leader in producing traveling science exhibitions and their associated educational programming (i.e. interactive websites, educator workshops, public talks, instructional materials). Two of its exhibitions, Space Weather Center and MarsQuest, are currently on tour. Another exhibition, Alien Earths, is in development. The Space Weather Center was developed in partnership with various research missions at NASA's Goddard Space Flight Center. MarsQuest is a 5000 square-foot traveling exhibition. The exhibit's second 3-year tour began this January at the Detroit Science Center. It is enabling millions of Americans to share in the excitement of the scientific exploration of Mars and to learn more about their own planet in the process. The 3,000 square-foot traveling exhibition, called Alien Earths, will bring origins-related research and discoveries to students and the American public. Alien Earths has four interrelated exhibit areas: Our Place in Space, Star Birth, PlanetQuest, and Search for Life. Exhibit visitors will explore the awesome events surrounding the birth of stars and planets; they will join scientists in the hunt for planets outside our solar system including those that may be in ``habitable zones'' around other stars; and finally they will be able to learn about how scientists are looking for signs of life beyond Earth. Besides the exhibits, SSI is also developing interactive web sites based on exhibit themes. New technologies are transforming the Web from a static medium to an interactive environment with tremendous

  17. New Hurricane Exhibit

    NASA Technical Reports Server (NTRS)

    2007-01-01

    A new exhibit in StenniSphere depicting NASA's role in hurricane prediction and research and SSC's role in helping the region recover from Hurricane Katrina. The cyclone-shaped exhibit focuses on the effects of the Aug. 29, 2005 storm and outlines how NASA is working to improve weather forecasting. Through photos, 3-D models and digital animations, the exhibit tells the story of what happened inside the storm and how NASA's scientific research can increase the accuracy of hurricane tracking and modeling.

  18. Human monocytes and macrophages undergo M1-type inflammatory polarization in response to high levels of glucose.

    PubMed

    Torres-Castro, Israel; Arroyo-Camarena, Úrsula D; Martínez-Reyes, Camilo P; Gómez-Arauz, Angélica Y; Dueñas-Andrade, Yareth; Hernández-Ruiz, Joselín; Béjar, Yadira L; Zaga-Clavellina, Verónica; Morales-Montor, Jorge; Terrazas, Luis I; Kzhyshkowska, Julia; Escobedo, Galileo

    2016-08-01

    Emerging data suggest that elevated glucose may promote inflammatory activation of monocytic lineage cells with the ability to injure vascular endothelial tissue of diabetic patients, however evidence in primary human monocytes and macrophages is still insufficient. We investigated the effect of high glucose concentration on the inflammatory capacity of human macrophages in vitro and examined whether similar responses were detectable in circulating monocytes from prediabetic patients. Primary monocytes were isolated from healthy blood donors and differentiated into macrophages. Differentiated macrophages were exposed to normal levels of glucose (NG), high glucose (HG) or high mannitol as osmotic pressure control (OP) for three days. Using PCR, ELISA and flow cytometry, we found that HG macrophages showed overexpression of CD11c and inducible nitric oxide synthase as well as down-regulation of arginase-1 and interleukin (IL)-10 with respect to NG and OP macrophages. Consistent with in vitro results, circulating monocytes from hyperglycemic patients exhibited higher levels of CD11c and lower expression of CD206 than monocytes from normoglycemic controls. In subjects with hyperglycemia, elevation in CD11c(+) monocytes was associated with increased obesity, insulin resistance, and triglyceridemia as well as low serum IL-10. Our data suggest that human monocytes and macrophages undergo M1-like inflammatory polarization when exposed to high levels of glucose on in vitro culture conditions and in patients with hyperglycemia. These results demonstrate that excess glucose has direct effects on macrophage activation though the molecular mechanisms mediating such a response remain to be elucidated. PMID:27269375

  19. Screening and incorporation of rust resistance from Allium cepa into bunching onion (Allium fistulosum) via alien chromosome addition.

    PubMed

    Wako, Tadayuki; Yamashita, Ken-ichiro; Tsukazaki, Hikaru; Ohara, Takayoshi; Kojima, Akio; Yaguchi, Shigenori; Shimazaki, Satoshi; Midorikawa, Naoko; Sakai, Takako; Yamauchi, Naoki; Shigyo, Masayoshi

    2015-04-01

    Bunching onion (Allium fistulosum L.; 2n = 16), bulb onion (Allium cepa L. Common onion group), and shallot (Allium cepa L. Aggregatum group) cultivars were inoculated with rust fungus, Puccinia allii, isolated from bunching onion. Bulb onions and shallots are highly resistant to rust, suggesting they would serve as useful resources for breeding rust resistant bunching onions. To identify the A. cepa chromosome(s) related to rust resistance, a complete set of eight A. fistulosum - shallot monosomic alien addition lines (MAALs) were inoculated with P. allii. At the seedling stage, FF+1A showed a high level of resistance in controlled-environment experiments, suggesting that the genes related to rust resistance could be located on shallot chromosome 1A. While MAAL, multi-chromosome addition line, and hypoallotriploid adult plants did not exhibit strong resistance to rust. In contrast to the high resistance of shallot, the addition line FF+1A+5A showed reproducibly high levels of rust resistance.

  20. Test Control Center exhibit

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Have you ever wondered how the engineers at John C. Stennis Space Center in Hancock County, Miss., test fire a Space Shuttle Main Engine? The Test Control Center exhibit at StenniSphere can answer your questions by simulating the test firing of a Space Shuttle Main Engine. A recreation of one of NASA's test control centers, the exhibit explains and portrays the 'shake, rattle and roar' that happens during a real test firing.

  1. Communicating Science through Exhibitions

    NASA Astrophysics Data System (ADS)

    Dusenbery, Paul

    2005-04-01

    It is critically important for the public to better understand the scientific process. Museum exhibitions are an important part of informal science education that can effectively reach public audiences as well as school groups. They provide an important gateway for the public to learn about compelling scientific endeavors. Science exhibitions also provide a marvelous opportunity for scientists to become engaged in the exhibit development process. The Space Science Institute (SSI) is a national leader in producing traveling science exhibitions and their associated educational programming (i.e. interactive websites, educator workshops, public talks, instructional materials). The focus of this presentation will be on two of its exhibit projects: MarsQuest (on tour for four years) and Alien Earths (its tour began early in 2005). MarsQuest is enabling millions of Americans to share in the excitement of the scientific exploration of Mars and to learn more about their own planet in the process. Alien Earths will bring origins-related research and discoveries to students and the American public. It has four interrelated exhibit areas: Our Place in Space, Star Birth, Planet Quest, and Search for Life. Exhibit visitors will explore the awesome events surrounding the birth of stars and planets; they will join scientists in the hunt for planets outside our solar system including those that may be in ``habitable zones'' around other stars; and finally they will be able to learn about how scientists are looking for signs of life beyond Earth. SSI is also developing interactive web sites based on exhibit themes. New technologies are transforming the Web from a static medium to an interactive environment with tremendous potential for informal education and inquiry-based investigations. This talk will focus on the role informal science projects play in effectively communicating science to a broad, public audience.

  2. Evaluation and selection of candidate high-level waste forms

    SciTech Connect

    Bernadzikowski, T. A.; Allender, J. S.; Butler, J. L.; Gordon, D. E.; Gould, Jr., T. H.; Stone, J. A.

    1982-03-01

    Seven candidate waste forms being developed under the direction of the Department of Energy's National High-Level Waste (HLW) Technology Program, were evaluated as potential media for the immobilization and geologic disposal of high-level nuclear wastes. The evaluation combined preliminary waste form evaluations conducted at DOE defense waste-sites and independent laboratories, peer review assessments, a product performance evaluation, and a processability analysis. Based on the combined results of these four inputs, two of the seven forms, borosilicate glass and a titanate based ceramic, SYNROC, were selected as the reference and alternative forms for continued development and evaluation in the National HLW Program. Both the glass and ceramic forms are viable candidates for use at each of the DOE defense waste-sites; they are also potential candidates for immobilization of commercial reprocessing wastes. This report describes the waste form screening process, and discusses each of the four major inputs considered in the selection of the two forms.

  3. Multipurpose optimization models for high level waste vitrification

    SciTech Connect

    Hoza, M.

    1994-08-01

    Optimal Waste Loading (OWL) models have been developed as multipurpose tools for high-level waste studies for the Tank Waste Remediation Program at Hanford. Using nonlinear programming techniques, these models maximize the waste loading of the vitrified waste and optimize the glass formers composition such that the glass produced has the appropriate properties within the melter, and the resultant vitrified waste form meets the requirements for disposal. The OWL model can be used for a single waste stream or for blended streams. The models can determine optimal continuous blends or optimal discrete blends of a number of different wastes. The OWL models have been used to identify the most restrictive constraints, to evaluate prospective waste pretreatment methods, to formulate and evaluate blending strategies, and to determine the impacts of variability in the wastes. The OWL models will be used to aid in the design of frits and the maximize the waste in the glass for High-Level Waste (HLW) vitrification.

  4. RETENTION OF SULFATE IN HIGH LEVEL RADIOACTIVE WASTE GLASS

    SciTech Connect

    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.

  5. Life Extension of Aging High Level Waste (HLW) Tanks

    SciTech Connect

    BRYSON, D.

    2002-02-04

    The Double Shell Tanks (DSTs) play a critical role in the Hanford High-Level Waste Treatment Complex, and therefore activities are underway to protect and better understand these tanks. The DST Life Extension Program is focused on both tank life extension and on evaluation of tank integrity. Tank life extension activities focus on understanding tank failure modes and have produced key chemistry and operations controls to minimize tank corrosion and extend useful tank life. Tank integrity program activities have developed and applied key technologies to evaluate the condition of the tank structure and predict useful tank life. Program results to date indicate that DST useful life can be extended well beyond the original design life and allow the existing tanks to fill a critical function within the Hanford High-Level Waste Treatment Complex. In addition the tank life may now be more reliably predicted, facilitating improved planning for the use and possible future replacement of these tanks.

  6. Management of data quality of high level waste characterization

    SciTech Connect

    Winters, W.I., Westinghouse Hanford

    1996-06-12

    Over the past 10 years, the Hanford Site has been transitioning from nuclear materials production to Site cleanup operations. High-level waste characterization at the Hanford Site provides data to support present waste processing operations, tank safety programs, and future waste disposal programs. Quality elements in the high-level waste characterization program will be presented by following a sample through the data quality objective, sampling, laboratory analysis and data review process. Transition from production to cleanup has resulted in changes in quality systems and program; the changes, as well as other issues in these quality programs, will be described. Laboratory assessment through quality control and performance evaluation programs will be described, and data assessments in the laboratory and final reporting in the tank characterization reports will be discussed.

  7. Case for retrievable high-level nuclear waste disposal

    USGS Publications Warehouse

    Roseboom, Eugene H.

    1994-01-01

    Plans for the nation's first high-level nuclear waste repository have called for permanently closing and sealing the repository soon after it is filled. However, the hydrologic environment of the proposed site at Yucca Mountain, Nevada, should allow the repository to be kept open and the waste retrievable indefinitely. This would allow direct monitoring of the repository and maintain the options for future generations to improve upon the disposal methods or use the uranium in the spent fuel as an energy resource.

  8. Automatic rule generation for high-level vision

    NASA Technical Reports Server (NTRS)

    Rhee, Frank Chung-Hoon; Krishnapuram, Raghu

    1992-01-01

    Many high-level vision systems use rule-based approaches to solving problems such as autonomous navigation and image understanding. The rules are usually elaborated by experts. However, this procedure may be rather tedious. In this paper, we propose a method to generate such rules automatically from training data. The proposed method is also capable of filtering out irrelevant features and criteria from the rules.

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

    SciTech Connect

    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.

  10. Handbook of high-level radioactive waste transportation

    SciTech Connect

    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.

  11. Overview of high-level waste management accomplishments

    SciTech Connect

    Lawroski, H; Berreth, J R; Freeby, W A

    1980-01-01

    Storage of power reactor spent fuel is necessary at present because of the lack of reprocessing operations particularly in the U.S. By considering the above solidification and storage scenario, there is more than reasonable assurance that acceptable, stable, low heat generation rate, solidified waste can be produced, and safely disposed. The public perception of no waste disposal solutions is being exploited by detractors of nuclear power application. The inability to even point to one overall system demonstration lends credibility to the negative assertions. By delaying the gathering of on-line information to qualify repository sites, and to implement a demonstration, the actions of the nuclear power detractors are self serving in that they can continue to point out there is no demonstration of satisfactory high-level waste disposal. By maintaining the liquid and solidified high-level waste in secure above ground storage until acceptable decay heat generation rates are achieved, by producing a compatible, high integrity, solid waste form, by providing a second or even third barrier as a compound container and by inserting the enclosed waste form in a qualified repository with spacing to assure moderately low temperature disposal conditions, there appears to be no technical reason for not progressing further with the disposal of high-level wastes and needed implementation of the complete nuclear power fuel cycle.

  12. High level cognitive information processing in neural networks

    NASA Technical Reports Server (NTRS)

    Barnden, John A.; Fields, Christopher A.

    1992-01-01

    Two related research efforts were addressed: (1) high-level connectionist cognitive modeling; and (2) local neural circuit modeling. The goals of the first effort were to develop connectionist models of high-level cognitive processes such as problem solving or natural language understanding, and to understand the computational requirements of such models. The goals of the second effort were to develop biologically-realistic model of local neural circuits, and to understand the computational behavior of such models. In keeping with the nature of NASA's Innovative Research Program, all the work conducted under the grant was highly innovative. For instance, the following ideas, all summarized, are contributions to the study of connectionist/neural networks: (1) the temporal-winner-take-all, relative-position encoding, and pattern-similarity association techniques; (2) the importation of logical combinators into connection; (3) the use of analogy-based reasoning as a bridge across the gap between the traditional symbolic paradigm and the connectionist paradigm; and (4) the application of connectionism to the domain of belief representation/reasoning. The work on local neural circuit modeling also departs significantly from the work of related researchers. In particular, its concentration on low-level neural phenomena that could support high-level cognitive processing is unusual within the area of biological local circuit modeling, and also serves to expand the horizons of the artificial neural net field.

  13. Laboratory and field evaluation of the impact of washings on the effectiveness of LifeNet®, Olyset® and PermaNet® 2.0 in two areas, where there is a high level of resistance of Anopheles gambiae to pyrethroids, Benin, West Africa

    PubMed Central

    2014-01-01

    Background An investigation carried out in Benin has shown that, in some areas close to rivers where density of mosquitoes is high, long-lasting, insecticidal bed nets (LLINs) are permanently used. In such areas, LLINs are washed every month. Based on this situation, the 20-wash minimum efficacy advised by the manufacturers would be inadequate. The main goal of this study was to evaluate the effectiveness of LifeNet®, Olyset® and Permanet® 2.0 washed several times against Anopheles gambiae sensu stricto (s.s.) populations, which have developed high resistance to pyrethroids. Methods Efficacy of LifeNet®, Olyset® and PermaNet® 2.0 washed 30 and 40 times was expressed in terms of blood-feeding inhibition rate, deterrence, induced exophily and mortality rates. This WHOPES phase II evaluation, conducted in experimental huts in Akron (southern Benin) and in Malanville (northern Benin), was accompanied by WHOPES Phase I evaluation. Results Over 40 successive washes, LifeNet® induced a mortality rate over 80% in phase I. However, beyond 10 washes, Permanet® 2.0 and Olyset induced dramatically reduced mortality rates, respectively 12.5 and 2.5%. With regard to Phase II results, unwashed LifeNet®, LifeNet® and Olyset® washed 30 and 40 times induced a similar exophily rate per study site (at least 58% in Malanville and at least 71% in Akron). Regarding blood feeding inhibition, LifeNet® and Olyset® washed 30 and 40 times significantly reduced wild An. gambiae s.s. blood feeding showing a similar personal protection as unwashed LifeNet®. LifeNet® washed 30 and 40 times induced mortality rates significantly higher than those induced by Olyset® and Permanet® 2.0 (P < 0,05). Conclusion LifeNet®, followed by Olyset®, have shown good efficacy against host-seeking resistant An. gambiae s.s. population in experimental huts in Benin. Lifenet® have shown to be an effective and promising vector control tool to prevent malaria in areas where repeated washings is

  14. Swamp to Space exhibit

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The menacing-looking alligator is really harmless. It is one of the realistic props to help convince visitors that the feel of the swamp is real in StenniSphere's Swamp to Space exhibit at John C. Stennis Space Center in Hancock County, Miss. The historical section of the Swamp to Space exhibit tells the story of why and how Stennis Space Center came to be. It also pays tribute to the families who moved their homes to make way for the space age in Mississippi.

  15. Ceramic process and plant design for high-level nuclear waste immobilization

    SciTech Connect

    Grantham, L.F.; McKisson, R.L.; De Wames, R.E.; Guon, J.; Flintoff, J.F.; McKenzie, D.E.

    1983-01-01

    In the last 3 years, significant advances in ceramic technology for high-level nuclear waste solidification have been made. Product quality in terms of leach-resistance, compositional uniformity, structural integrity, and thermal stability promises to be superior to borosilicate glass. This paper addresses the process effectiveness and preliminary designs for glass and ceramic immobilization plants. The reference two-step ceramic process utilizes fluid-bed calcination (FBC) and hot isostatic press (HIP) consolidation. Full-scale demonstration of these well-developed processing steps has been established at DOE and/or commercial facilities for processing radioactive materials. Based on Savannah River-type waste, our model predicts that the capital and operating cost for the solidification of high-level nuclear waste is about the same for the ceramic and glass options. However, when repository costs are included, the ceramic option potentially offers significantly better economics due to its high waste loading and volume reduction. Volume reduction impacts several figures of merit in addition to cost such as system logistics, storage, transportation, and risk. The study concludes that the ceramic product/process has many potential advantages, and rapid deployment of the technology could be realized due to full-scale demonstrations of FBC and HIP technology in radioactive environments. Based on our finding and those of others, the ceramic innovation not only offers a viable backup to the glass reference process but promises to be a viable future option for new high-level nuclear waste management opportunities.

  16. Antibiotic resistance in soil and water environments.

    PubMed

    Esiobu, Nwadiuto; Armenta, Lisa; Ike, Joseph

    2002-06-01

    Seven locations were screened for antibiotic-resistant bacteria using a modified agar dilution technique. Isolates resistant to high levels of antibiotics were screened for r plasmids. Low-level resistance (25 micro g x ml(-1)) was widespread for ampicillin, penicillin, tetracycline, vancomycin and streptomycin but not for kanamycin. Resistant populations dropped sharply at high antibiotic levels, suggesting that intrinsic non-emergent mechanisms were responsible for the multiple drug resistance exhibited at low doses. Dairy farm manure contained significantly (P < 0.01) more (%) resistant bacteria than the other sites. Bacteria isolated from a dairy water canal, a lake by a hospital and a residential garden (fertilized by farm manure) displayed resistance frequencies of 77, 75 and 70%, respectively. Incidence of tetracycline resistance was most prevalent at 47-89% of total bacteria. Out of 200 representative isolates analyzed, Pseudomonas, Enterococcus-like bacteria, Enterobacter and Burkholderia species constituted the dominant reservoirs of resistance at high drug levels (50-170 micro g x ml(-1)). Plasmids were detected in only 29% (58) of these bacteria with tetracycline resistance accounting for 65% of the plasmid pool. Overall, resistance trends correlated to the abundance and type of bacterial species present in the habitat. Environmental reservoirs of resistance include opportunistic pathogens and constitute some public health concern. PMID:12396530

  17. Exhibition in Sight

    ERIC Educational Resources Information Center

    Wasserman, Burton

    1978-01-01

    Ludwig Mies van der Rohe is known primarily as an architect. However, he also designed chairs and tables. Discusses an exhibit held in New York City a few months ago which showed how well the famous architect achieved his goals in the area of furniture design. (Author/RK)

  18. Exhibition in Sight

    ERIC Educational Resources Information Center

    Wasserman, Burton

    1978-01-01

    One of the most offbeat exhibitions presented in the last several years was the widely celebrated Warhol-Wyeth duo show, "Portraits of Each Other", held at the Brandywine River Museum in Chadds Ford, Pennsylvania. Discusses their paintings and their diametrically different personalities. (Author/RK)

  19. Development of a High Level Waste Tank Inspection System

    SciTech Connect

    Appel, D.K.; Loibl, M.W.; Meese, D.C.

    1995-03-21

    The Westinghouse Savannah River Technology Center was requested by it`s sister site, West Valley Nuclear Service (WVNS), to develop a remote inspection system to gather wall thickness readings of their High Level Waste Tanks. WVNS management chose to take a proactive approach to gain current information on two tanks t hat had been in service since the early 70`s. The tanks contain high level waste, are buried underground, and have only two access ports to an annular space between the tank and the secondary concrete vault. A specialized remote system was proposed to provide both a visual surveillance and ultrasonic thickness measurements of the tank walls. A magnetic wheeled crawler was the basis for the remote delivery system integrated with an off-the-shelf Ultrasonic Data Acquisition System. A development program was initiated for Savannah River Technology Center (SRTC) to design, fabricate, and test a remote system based on the Crawler. The system was completed and involved three crawlers to perform the needed tasks, an Ultrasonic Crawler, a Camera Crawler, and a Surface Prep Crawler. The crawlers were computer controlled so that their operation could be done remotely and their position on the wall could be tracked. The Ultrasonic Crawler controls were interfaced with ABB Amdata`s I-PC, Ultrasonic Data Acquisition System so that thickness mapping of the wall could be obtained. A second system was requested by Westinghouse Savannah River Company (WSRC), to perform just ultrasonic mapping on their similar Waste Storage Tanks; however, the system needed to be interfaced with the P-scan Ultrasonic Data Acquisition System. Both remote inspection systems were completed 9/94. Qualifications tests were conducted by WVNS prior to implementation on the actual tank and tank development was achieved 10/94. The second inspection system was deployed at WSRC 11/94 with success, and the system is now in continuous service inspecting the remaining high level waste tanks at WSRC.

  20. High-level waste management technology program plan

    SciTech Connect

    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.

  1. Overview of the Spanish high-level waste program

    SciTech Connect

    Ulibarri, A.; Beceiro, A.R.

    1995-12-31

    The Empresa Nacional de Residuos Radiactivos, S.A. (ENRESA) was set up in 1984 with the mandate to be responsible for the management of all radioactive wastes generated in Spain. The strategy and main guidelines of ENRESA`s program to fulfill this mandate are contained in the General Radioactive Waste Plan (PGRR), a basic document which ENRESA is due to submit every year to the Ministry of Industry and Energy for Government approval. The Spanish nuclear electricity generating program consists of nine Light Water Reactors (LWR) with an overall capacity of 7.1 GWe, after the Vandellos 1 nuclear power plant were phased-out in 1989. The spent nuclear fuel from LWRs is defined, in accordance with the 1983 National Energy Plan, as high level waste, and its management is accordingly focused to the direct disposal option. The spent nuclear fuel from Vandellos 1, a graphite gas-cooled reactor which was in operation from 1972 to 1989, in reprocessed abroad, and the wastes generated in the processes will be returned to Spain. The final objective of the Spanish High Level Waste program is to dispose of the spent nuclear fuel and high level vitrified waste into a deep geological repository. In fulfilling this target, taking into account the time frame in which it can reasonably be achieved, a previous step is necessary in order to secure the temporary storage of the spent fuel. This paper presents the strategy and a description of the different elements of the program currently under way as established in the fourth General Radioactive Waste Plan that has been approved by the Government in December 1994.

  2. High-level neutron coincidence counter maintenance manual

    SciTech Connect

    Swansen, J.; Collinsworth, P.

    1983-05-01

    High-level neutron coincidence counter operational (field) calibration and usage is well known. This manual makes explicit basic (shop) check-out, calibration, and testing of new units and is a guide for repair of failed in-service units. Operational criteria for the major electronic functions are detailed, as are adjustments and calibration procedures, and recurrent mechanical/electromechanical problems are addressed. Some system tests are included for quality assurance. Data on nonstandard large-scale integrated (circuit) components and a schematic set are also included.

  3. CLASSIFICATION OF THE MGR DEFENSE HIGH LEVEL WASTE DISPOSAL CONTIANER

    SciTech Connect

    J.A. Ziegler

    1999-08-31

    The purpose of this analysis is to document the Quality Assurance (QA) classification of the Monitored Geologic Repository (MGR) defense high-level waste disposal container system structures, systems and components (SSCs) performed by the MGR Safety Assurance Department. This analysis also provides the basis for revision of YMP/90-55Q, Q-List (YMP 1998). The Q-List identifies those MGR SSCs subject to the requirements of DOE/RW-0333PY ''Quality Assurance Requirements and Description'' (QARD) (DOE 1998).

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

    SciTech Connect

    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.

  5. High-level wastes: DOE names three sites for characterization

    SciTech Connect

    1986-07-01

    DOE announced in May 1986 that there will be there site characterization studies made to determine suitability for a high-level radioactive waste repository. The studies will include several test drillings to the proposed disposal depths. Yucca Mountain, Nevada; Deaf Smith Country, Texas, and Hanford, Washington were identified as the study sites, and further studies for a second repository site in the East were postponed. The affected states all filed suits in federal circuit courts because they were given no advance warning of the announcement of their selection or the decision to suspend work on a second repository. Criticisms of the selection process include the narrowing or DOE options.

  6. Very-high-level neutral-beam control system

    SciTech Connect

    Elischer, V.; Jacobson, V.; Theil, E.

    1981-10-01

    As increasing numbers of neutral beams are added to fusion machines, their operation can consume a significant fraction of a facility's total resources. LBL has developed a very high level control system that allows a neutral beam injector to be treated as a black box with just 2 controls: one to set the beam power and one to set the pulse duration. This 2 knob view allows simple operation and provides a natural base for implementing even higher level controls such as automatic source conditioning.

  7. Spanish high level radioactive waste management system issues

    SciTech Connect

    Ulibarri, A.; Veganzones, A.

    1993-12-31

    The Empresa Nacional de Residuous Radiactivos, S.A. (ENRESA) was set up in 1984 as a state-owned limited liability company to be responsible for the management of all kinds of radioactive wastes in Spain. This paper provides an overview of the strategy and main lines of action stated in the third General Radioactive Waste Plan, currently in force, for the management of spent nuclear fuel and high-level wastes, as well as an outline of the main related projects, either being developed or foreseen. Aspects concerning the organizational structure, the economic and financing system and the international co-operational are also included.

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

    SciTech Connect

    Mahidhara, R.K.; Elleman, T.S.; Murty, K.L.

    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. Modern Alchemy: Solidifying high-level nuclear waste

    SciTech Connect

    Newton, C.C.

    1997-07-01

    The U.S. Department of Energy is putting a modern version of alchemy to work to produce an answer to a decades-old problem. It is taking place at the Savannah River Site (SRS) in Aiken, South Carolina and at the West Valley Demonstration Project (WVDP) near Buffalo, New York. At both locations, contractor Westinghouse Electric Corporation is applying technology that is turning liquid high-level radioactive waste (HLW) into a stabilized, durable glass for safer and easier management. The process is called vitrification. SRS and WVDP are now operating the nation`s first full-scale HLW vitrification plants.

  10. Long-term high-level waste technology. Composite report

    NASA Astrophysics Data System (ADS)

    Cornman, W. R.

    1981-12-01

    Research and development studies on the immobilization of high-level wastes from the chemical reprocessing of nuclear reactor fuels are summarized. The reports are grouped under the following tasks: (1) program management and support; (2) waste preparation; (3) waste fixation; and (4) final handling. Some of the highlights are: leaching properties were obtained for titanate and tailored ceramic materials being developed at ICPP to immobilize zirconia calcine; comparative leach tests, hot-cell tests, and process evaluations were conducted of waste form alternatives to borosilicate glass for the immobilization of SRP high-level wastes, experiments were run at ANL to qualify neutron activation analysis and radioactive tracers for measuring leach rates from simulated waste glasses; comparative leach test samples of SYNROC D were prepared, characterized, and tested at LLNL; encapsulation of glass marbles with lead or lead alloys was demonstrated on an engineering scale at PNL; a canister for reference Commercial HLW was designed at PNL; a study of the optimization of salt-crete was completed at SRL; a risk assessment showed that an investment for tornado dampers in the interim storage building of the DWPF is unjustified.

  11. Permitting plan for the high-level waste interim storage

    SciTech Connect

    Deffenbaugh, M.L.

    1997-04-23

    This document addresses the environmental permitting requirements for the transportation and interim storage of solidified high-level waste (HLW) produced during Phase 1 of the Hanford Site privatization effort. Solidified HLW consists of canisters containing vitrified HLW (glass) and containers that hold cesium separated during low-level waste pretreatment. The glass canisters and cesium containers will be transported to the Canister Storage Building (CSB) in a U.S. Department of Energy (DOE)-provided transportation cask via diesel-powered tractor trailer. Tri-Party Agreement (TPA) Milestone M-90 establishes a new major milestone, and associated interim milestones and target dates, governing acquisition and/or modification of facilities necessary for: (1) interim storage of Tank Waste Remediation Systems (TWRS) immobilized HLW (IHLW) and other canistered high-level waste forms; and (2) interim storage and disposal of TWRS immobilized low-activity tank waste (ILAW). An environmental requirements checklist and narrative was developed to identify the permitting path forward for the HLW interim storage (HLWIS) project (See Appendix B). This permitting plan will follow the permitting logic developed in that checklist.

  12. Local acceptance of a high-level nuclear waste repository.

    PubMed

    Sjöberg, Lennart

    2004-06-01

    The siting of nuclear waste facilities has been very difficult in all countries. Recent experience in Sweden indicates, however, that it may be possible, under certain circumstances, to gain local support for the siting of a high-level nuclear waste (HLNW) repository. The article reports on a study of attitudes and risk perceptions of people living in four municipalities in Sweden where HLNW siting was being intensely discussed at the political level, in media, and among the public. Data showed a relatively high level of consensus on acceptability of at least further investigation of the issue; in two cases local councils have since voted in favor of a go-ahead, and in one case only a very small majority defeated the issue. Models of policy attitudes showed that these were related to attitude to nuclear power, attributes of the perceived HLNW risk, and trust. Factors responsible for acceptance are discussed at several levels. One is the attitude to nuclear power, which is becoming more positive, probably because no viable alternatives are in sight. Other factors have to do with the extensive information programs conducted in these municipalities, and with the logical nature of the conclusion that they would be good candidates for hosting the national HLNW repository.

  13. Space augmentation of military high-level waste disposal

    NASA Technical Reports Server (NTRS)

    English, T.; Lees, L.; Divita, E.

    1979-01-01

    Space disposal of selected components of military high-level waste (HLW) is considered. This disposal option offers the promise of eliminating the long-lived radionuclides in military HLW from the earth. A space mission which meets the dual requirements of long-term orbital stability and a maximum of one space shuttle launch per week over a period of 20-40 years, is a heliocentric orbit about halfway between the orbits of earth and Venus. Space disposal of high-level radioactive waste is characterized by long-term predictability and short-term uncertainties which must be reduced to acceptably low levels. For example, failure of either the Orbit Transfer Vehicle after leaving low earth orbit, or the storable propellant stage failure at perihelion would leave the nuclear waste package in an unplanned and potentially unstable orbit. Since potential earth reencounter and subsequent burn-up in the earth's atmosphere is unacceptable, a deep space rendezvous, docking, and retrieval capability must be developed.

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

    SciTech Connect

    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.

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

    SciTech Connect

    Not Available

    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.

  16. Spent fuel and high-level radioactive waste transportation report

    SciTech Connect

    Not Available

    1990-11-01

    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 the Southern States Energy Board (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.

  17. Spent fuel and high-level radioactive waste transportation report

    SciTech Connect

    Not Available

    1989-11-01

    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 the Southern States Energy Board (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 sew be supplied to all parties in receipt of this publication provided they remain on the SSEB mailing list.

  18. Burning high-level TRU waste in fusion fission reactors

    NASA Astrophysics Data System (ADS)

    Shen, Yaosong

    2016-09-01

    Recently, the concept of actinide burning instead of a once-through fuel cycle for disposing spent nuclear fuel seems to get much more attention. A new method of burning high-level transuranic (TRU) waste combined with Thorium-Uranium (Th-U) fuel in the subcritical reactors driven by external fusion neutron sources is proposed in this paper. The thorium-based TRU fuel burns all of the long-lived actinides via a hard neutron spectrum while outputting power. A one-dimensional model of the reactor concept was built by means of the ONESN_BURN code with new data libraries. The numerical results included actinide radioactivity, biological hazard potential, and much higher burnup rate of high-level transuranic waste. The comparison of the fusion-fission reactor with the thermal reactor shows that the harder neutron spectrum is more efficient than the soft. The Th-U cycle produces less TRU, less radiotoxicity and fewer long-lived actinides. The Th-U cycle provides breeding of 233U with a long operation time (>20 years), hence significantly reducing the reactivity swing while improving safety and burnup.

  19. How to achieve high-level expression of microbial enzymes

    PubMed Central

    Liu, Long; Yang, Haiquan; Shin, Hyun-dong; Chen, Rachel R.; Li, Jianghua; Du, Guocheng; Chen, Jian

    2013-01-01

    Microbial enzymes have been used in a large number of fields, such as chemical, agricultural and biopharmaceutical industries. The enzyme production rate and yield are the main factors to consider when choosing the appropriate expression system for the production of recombinant proteins. Recombinant enzymes have been expressed in bacteria (e.g., Escherichia coli, Bacillus and lactic acid bacteria), filamentous fungi (e.g., Aspergillus) and yeasts (e.g., Pichia pastoris). The favorable and very advantageous characteristics of these species have resulted in an increasing number of biotechnological applications. Bacterial hosts (e.g., E. coli) can be used to quickly and easily overexpress recombinant enzymes; however, bacterial systems cannot express very large proteins and proteins that require post-translational modifications. The main bacterial expression hosts, with the exception of lactic acid bacteria and filamentous fungi, can produce several toxins which are not compatible with the expression of recombinant enzymes in food and drugs. However, due to the multiplicity of the physiological impacts arising from high-level expression of genes encoding the enzymes and expression hosts, the goal of overproduction can hardly be achieved, and therefore, the yield of recombinant enzymes is limited. In this review, the recent strategies used for the high-level expression of microbial enzymes in the hosts mentioned above are summarized and the prospects are also discussed. We hope this review will contribute to the development of the enzyme-related research field. PMID:23686280

  20. High level language-based robotic control system

    NASA Technical Reports Server (NTRS)

    Rodriguez, Guillermo (Inventor); Kreutz, Kenneth K. (Inventor); Jain, Abhinandan (Inventor)

    1996-01-01

    This invention is a robot control system based on a high level language implementing a spatial operator algebra. There are two high level languages included within the system. At the highest level, applications programs can be written in a robot-oriented applications language including broad operators such as MOVE and GRASP. The robot-oriented applications language statements are translated into statements in the spatial operator algebra language. Programming can also take place using the spatial operator algebra language. The statements in the spatial operator algebra language from either source are then translated into machine language statements for execution by a digital control computer. The system also includes the capability of executing the control code sequences in a simulation mode before actual execution to assure proper action at execution time. The robot's environment is checked as part of the process and dynamic reconfiguration is also possible. The languages and system allow the programming and control of multiple arms and the use of inward/outward spatial recursions in which every computational step can be related to a transformation from one point in the mechanical robot to another point to name two major advantages.

  1. High level language-based robotic control system

    NASA Technical Reports Server (NTRS)

    Rodriguez, Guillermo (Inventor); Kruetz, Kenneth K. (Inventor); Jain, Abhinandan (Inventor)

    1994-01-01

    This invention is a robot control system based on a high level language implementing a spatial operator algebra. There are two high level languages included within the system. At the highest level, applications programs can be written in a robot-oriented applications language including broad operators such as MOVE and GRASP. The robot-oriented applications language statements are translated into statements in the spatial operator algebra language. Programming can also take place using the spatial operator algebra language. The statements in the spatial operator algebra language from either source are then translated into machine language statements for execution by a digital control computer. The system also includes the capability of executing the control code sequences in a simulation mode before actual execution to assure proper action at execution time. The robot's environment is checked as part of the process and dynamic reconfiguration is also possible. The languages and system allow the programming and control of multiple arms and the use of inward/outward spatial recursions in which every computational step can be related to a transformation from one point in the mechanical robot to another point to name two major advantages.

  2. Behavior construction and refinement from high-level specifications

    NASA Astrophysics Data System (ADS)

    Martignoni, Andrew J., III; Smart, William D.

    2004-12-01

    Mobile robots are excellent examples of systems that need to show a high level of autonomy. Often robots are loosely supervised by humans who are not intimately familiar with the inner workings of the robot. We cannot generally predict exact environmental conditions in which the robot will operate in advance. This means that the behavior must be adapted in the field. Untrained individuals cannot (and probably should not) program the robot to effect these changes. We need a system that will (a) allow re-tasking, and (b) allow adaptation of the behavior to the specific conditions in the field. In this paper we concentrate on (b). We will describe how to assemble controllers, based on high-level descriptions of the behavior. We will show how the behavior can be tuned by the human, despite not knowing how the code is put together. We will also show how this can be done automatically, using reinforcement learning, and point out the problems that must be overcome for this approach to work.

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

    NASA Technical Reports Server (NTRS)

    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.

  4. High-level power analysis and optimization techniques

    NASA Astrophysics Data System (ADS)

    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

  5. Starship 2040 Exhibit

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This photograph shows onlookers viewing displays within the Starship 2040 exhibit on display at Joe Davis Stadium in Huntsville, Alabama. Developed by the Space Transportation Directorate at Marshall Space Flight Center (MSFC), the Starship 2040 exhibit is housed in a 48-ft (14.6-m) tractor and trailer rig, permitting it to travel around the Nation, demonstrating NASA's vision of what commercial spaceflight might be like 40 years from now. All the irnovations suggested aboard the exhibit (automated vehicle health monitoring systems, high-energy propulsion drive, navigational aids, and emergency and safety systems) are based on concepts and technologies now being studied at NASA Centers and partner institutions around the Nation. NASA is the Nation's premier agency for development of the space transportation system, including future-generation reusable launch vehicles. Such systems, the keys to a 'real' Starship 2040, require revolutionary advances in critical aerospace technologies, from thermal, magnetic, chemical, and propellantless propulsion systems to new energy sources such as space solar power or antimatter propulsion. These and other advances are now being studied, developed, and tested at NASA field centers and partner institutions all over the Nation.

  6. Starship 2040 Exhibit

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This photograph shows Justin Varnadore, son of a Marshall TV employee, at the controls of one of the many displays within the Starship 2040 exhibit on display at Joe Davis Stadium in Huntsville, Alabama. Developed by the Space Transportation Directorate at Marshall Space Flight Center (MSFC), the Starship 2040 exhibit is housed in a 48-ft (14.6-m) tractor and trailer rig, permitting it to travel around the Nation, demonstrating NASA's vision of what commercial spaceflight might be like 40 years from now. All the irnovations suggested aboard the exhibit (automated vehicle health monitoring systems, high-energy propulsion drive, navigational aids, and emergency and safety systems) are based on concepts and technologies now being studied at NASA Centers and partner institutions around the Nation. NASA is the Nation's premier agency for development of the space transportation system, including future-generation reusable launch vehicles. Such systems, the keys to a 'real' Starship 2040, require revolutionary advances in critical aerospace technologies, from thermal, magnetic, chemical, and propellantless propulsion systems to new energy sources such as space solar power or antimatter propulsion. These and other advances are now being studied, developed, and tested at NASA field centers and partner institutions all over the Nation.

  7. Starship 2040 Exhibit

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This photograph shows the Starship 2040 leaving the Marshall Space Flight Center (MSFC) for the exhibit site. Developed by the Space Transportation Directorate at MSFC, the Starship 2040 exhibit is housed in a 48-ft (14.6-m) tractor and trailer rig, permitting it to travel around the Nation, demonstrating NASA's vision of what commercial spaceflight might be like 40 years from now. All the irnovations suggested aboard the exhibit, automated vehicle health monitoring systems, high-energy propulsion drive, navigational aids and emergency and safety systems, are based on concepts and technologies now being studied at NASA Centers and partner institutions around the Nation. NASA is the nation's premier agency for development of the space transportation system, including future-generation reusable launch vehicles. Such systems, the keys to a 'real' Starship 2040, require revolutionary advances in critical aerospace technologies, from thermal, magnetic, chemical, and propellantless propulsion systems to new energy sources such as space solar power or antimatter propulsion. These and other advances are now being studied, developed, and tested at NASA field centers and partner institutions all over the Nation.

  8. Online Exhibits & Concept Maps

    NASA Astrophysics Data System (ADS)

    Douma, M.

    2009-12-01

    Presenting the complexity of geosciences to the public via the Internet poses a number of challenges. For example, utilizing various - and sometimes redundant - Web 2.0 tools can quickly devour limited time. Do you tweet? Do you write press releases? Do you create an exhibit or concept map? The presentation will provide participants with a context for utilizing Web 2.0 tools by briefly highlighting methods of online scientific communication across several dimensions. It will address issues of: * breadth and depth (e.g. from narrow topics to well-rounded views), * presentation methods (e.g. from text to multimedia, from momentary to enduring), * sources and audiences (e.g. for experts or for the public, content developed by producers to that developed by users), * content display (e.g. from linear to non-linear, from instructive to entertaining), * barriers to entry (e.g. from an incumbent advantage to neophyte accessible, from amateur to professional), * cost and reach (e.g. from cheap to expensive), and * impact (e.g. the amount learned, from anonymity to brand awareness). Against this backdrop, the presentation will provide an overview of two methods of online information dissemination, exhibits and concept maps, using the WebExhibits online museum (www.webexhibits.org) and SpicyNodes information visualization tool (www.spicynodes.org) as examples, with tips on how geoscientists can use either to communicate their science. Richly interactive online exhibits can serve to engage a large audience, appeal to visitors with multiple learning styles, prompt exploration and discovery, and present a topic’s breadth and depth. WebExhibits, which was among the first online museums, delivers interactive information, virtual experiments, and hands-on activities to the public. While large, multidisciplinary exhibits on topics like “Color Vision and Art” or “Calendars Through the Ages” require teams of scholars, user interface experts, professional writers and editors

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

    SciTech Connect

    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.

  10. High level radioactive waste vitrification process equipment component testing

    NASA Astrophysics Data System (ADS)

    Siemens, D. H.; Health, W. C.; Larson, D. E.; Craig, S. N.; Berger, D. N.; Goles, R. W.

    1985-04-01

    Remote operability and maintainability of vitrification equipment were assessment under shielded cell conditions. The equipment tested will be applied to immobilize high level and transuranic liquid waste slurries that resulted from plutonium production for defense weapons. Equipment tested included: a turntable for handling waste canisters under the melter; a removable discharge cone in the melter overflow section; a thermocouple jumper that extends into a shielded cell; remote instrument and electrical connectors; remote, mechanical, and heat transfer aspects of the melter glass overflow section; a reamer to clean out plugged nozzles in the melter top; a closed circuit camera to view the melter interior; and a device to retrieve samples of the glass product. A test was also conduucted to evaluate liquid metals for use in a liquid metal sealing system.

  11. Characterization of composite ceramic high level waste forms.

    SciTech Connect

    Frank, S. M.; Bateman, K. J.; DiSanto, T.; Johnson, S. G.; Moschetti, T. L.; Noy, M. H.; O'Holleran, T. P.

    1997-12-05

    Argonne National Laboratory has developed a composite ceramic waste form for the disposition of high level radioactive waste produced during electrometallurgical conditioning of spent nuclear fuel. The electrorefiner LiCl/KCl eutectic salt, containing fission products and transuranics in the chloride form, is contacted with a zeolite material which removes the fission products from the salt. After salt contact, the zeolite is mixed with a glass binder. The zeolite/glass mixture is then hot isostatic pressed (HIPed) to produce the composite ceramic waste form. The ceramic waste form provides a durable medium that is well suited to incorporate fission products and transuranics in the chloride form. Presented are preliminary results of the process qualification and characterization studies, which include chemical and physical measurements and product durability testing, of the ceramic waste form.

  12. Calculates Neutron Production in Canisters of High-level Waste

    1993-01-15

    ALPHN calculates the (alpha,n) neutron production rate of a canister of vitrified high-level waste. The user supplies the chemical composition of the glass or glass-ceramic and the curies of the alpha-emitting actinides present. The output of the program gives the (alpha,n) neutron production of each actinide in neutrons per second and the total for the canister. The (alpha,n) neutron production rates are source terms only; that is, they are production rates within the glass andmore » do not take into account the shielding effect of the glass. For a given glass composition, the user can calculate up to eight cases simultaneously; these cases are based on the same glass composition but contain different quantities of actinides per canister.« less

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

    PubMed

    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. PMID:26043208

  14. Review of High Level Waste Tanks Ultrasonic Inspection Data

    SciTech Connect

    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.

  15. Remote ignitability analysis of high-level radioactive waste

    SciTech Connect

    Lundholm, C.W.; Morgan, J.M.; Shurtliff, R.M.; Trejo, L.E.

    1992-09-01

    The Idaho Chemical Processing Plant (ICPP), was used to reprocess nuclear fuel from government owned reactors to recover the unused uranium-235. These processes generated highly radioactive liquid wastes which are stored in large underground tanks prior to being calcined into a granular solid. The Resource Conservation and Recovery Act (RCRA) and state/federal clean air statutes require waste characterization of these high level radioactive wastes for regulatory permitting and waste treatment purposes. The determination of the characteristic of ignitability is part of the required analyses prior to calcination and waste treatment. To perform this analysis in a radiologically safe manner, a remoted instrument was needed. The remote ignitability Method and Instrument will meet the 60 deg. C. requirement as prescribed for the ignitability in method 1020 of SW-846. The method for remote use will be equivalent to method 1020 of SW-846.

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

    PubMed Central

    Altmann, Lori J. P.; Troche, Michelle S.

    2011-01-01

    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. PMID:21860777

  17. High level radioactive waste vitrification process equipment component testing

    SciTech Connect

    Siemens, D.H.; Heath, W.O.; Larson, D.E.; Craig, S.N.; Berger, D.N.; Goles, R.W.

    1985-04-01

    Remote operability and maintainability of vitrification equipment were assessed under shielded-cell conditions. The equipment tested will be applied to immobilize high-level and transuranic liquid waste slurries that resulted from plutonium production for defense weapons. Equipment tested included: a turntable for handling waste canisters under the melter; a removable discharge cone in the melter overflow section; a thermocouple jumper that extends into a shielded cell; remote instrument and electrical connectors; remote, mechanical, and heat transfer aspects of the melter glass overflow section; a reamer to clean out plugged nozzles in the melter top; a closed circuit camera to view the melter interior; and a device to retrieve samples of the glass product. A test was also conducted to evaluate liquid metals for use in a liquid metal sealing system.

  18. Linearization of the Fermilab recycler high level RF

    SciTech Connect

    Joseph E Dey; Tom Kubicki; John Reid

    2003-05-28

    In studying the Recycler high level RF, it was found that at 89 kHz, the lowest frequency required by the system, some nonlinearities in magnitude and phase were discovered. The visible evidence of this was that beam injected in a barrier bucket had a definite slope at the top. Using a network analyzer, the S-parameter S{sub 21} was realized for the overall system and from mathematical modeling a second order numerator and denominator transfer function was found. The inverse of this transfer function gives their linearization transfer function. The linearization transfer function was realized in hardware by summing a high pass, band pass and low pass filter together. The resulting magnitude and phase plots, along with actual beam response will be shown.

  19. 4.5 Meter high level waste canister study

    SciTech Connect

    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.

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

    PubMed

    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.

  1. SIMULANT DEVELOPMENT FOR SAVANNAH RIVER SITE HIGH LEVEL WASTE

    SciTech Connect

    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.

  2. High-level waste tank farm set point document

    SciTech Connect

    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.

  3. High levels of subgenomic HCV plasma RNA in immunosilent infections

    PubMed Central

    Bernardin, Flavien; Stramer, Susan; Rehermann, Barbara; Page-Shafer, Kimberly; Cooper, Stewart; Bangsberg, David; Hahn, Judith; Tobler, Leslie; Busch, Michael; Delwart, Eric

    2007-01-01

    A genetic analysis of hepatitis C virus (HCV) in rare blood donors who remained HCV seronegative despite long-term high-level viremia revealed the chronic presence of HCV genomes with large in frame deletions in their structural genes. Full-length HCV genomes were only detected as minority variants. In one immunodeficiency virus (HIV) co-infected donor the truncated HCV genome transiently decreased in frequency concomitant with delayed seroconversion and re-emerged following partial seroreversion. The long-term production of heavily truncated HCV genomes in vivo suggests that these viruses retained the necessary elements for RNA replication while the deleted structural functions necessary for their spread in vivo was provided in trans by wild type helper virus in co-infected cells. The absence of immunological pressure and a high viral load may therefore promote the emergence of truncated HCV subgenomic replicons in vivo. PMID:17493654

  4. Exceptionally high levels of multiple mating in an army ant

    NASA Astrophysics Data System (ADS)

    Denny, A. Jay; Franks, Nigel R.; Powell, Scott; Edwards, Keith J.

    Most species of social insects have singly mated queens, although there are notable exceptions. Competing hypotheses have been proposed to explain the evolution of high levels of multiple mating, but this issue is far from resolved. Here we use microsatellites to investigate mating frequency in the army ant Eciton burchellii and show that queens mate with an exceptionally large number of males, eclipsing all but one other social insect species for which data are available. In addition we present evidence that suggests that mating is serial, continuing throughout the lifetime of the queen. This is the first demonstration of serial mating among social hymenoptera. We propose that high paternity within colonies is most likely to have evolved to increase genetic diversity and to counter high pathogen and parasite loads.

  5. Socioeconomic studies of high-level nuclear waste disposal.

    PubMed Central

    White, G F; Bronzini, M S; Colglazier, E W; Dohrenwend, B; Erikson, K; Hansen, R; Kneese, A V; Moore, R; Page, E B; Rappaport, R A

    1994-01-01

    The socioeconomic investigations of possible impacts of the proposed repository for high-level nuclear waste at Yucca Mountain, Nevada, have been unprecedented in several respects. They bear on the public decision that sooner or later will be made as to where and how to dispose permanently of the waste presently at military weapons installations and that continues to accumulate at nuclear power stations. No final decision has yet been made. There is no clear precedent from other countries. The organization of state and federal studies is unique. The state studies involve more disciplines than any previous efforts. They have been carried out in parallel to federal studies and have pioneered in defining some problems and appropriate research methods. A recent annotated bibliography provides interested scientists with a compact guide to the 178 published reports, as well as to relevant journal articles and related documents. PMID:7971963

  6. Space Shuttle Cockpit exhibit

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Want to sit in the cockpit of the Space Shuttle and watch astronauts work in outer space? At StenniSphere, you can do that and much more. StenniSphere, the visitor center at John C. Stennis Space Center in Hancock County, Miss., presents 14,000-square-feet of interactive exhibits that depict America's race for space as well as a glimpse of the future. StenniSphere is open free of charge from 9 a.m. to 5 p.m. daily.

  7. Smithsonian climate change exhibits

    NASA Astrophysics Data System (ADS)

    Kumar, Mohi

    2006-05-01

    Two new museum exhibits, ``Arctic: A Friend Acting Strangely'' and ``Atmosphere: Change is in the Air'' opened 15 April at the Smithsonian Institution's National Museum of Natural History in Washington, D.C., in partnership with the U.S. National Oceanic and Atmospheric Administration, NASA, and the U.S. National Science Foundation. In ``Arctic: A Friend Acting Strangely,'' anecdotes from indigenous polar people reveal how climate changes have affected life within the last 50 years. For example, as permafrost melts and sea ice shrinks, plant distributions and animal migration patterns are changing, severely affecting culture.

  8. High-level hepatitis B virus replication in transgenic mice.

    PubMed Central

    Guidotti, L G; Matzke, B; Schaller, H; Chisari, F V

    1995-01-01

    Hepatitis B virus (HBV) transgenic mice whose hepatocytes replicate the virus at levels comparable to that in the infected livers of patients with chronic hepatitis have been produced, without any evidence of cytopathology. High-level viral gene expression was obtained in the liver and kidney tissues in three independent lineages. These animals were produced with a terminally redundant viral DNA construct (HBV 1.3) that starts just upstream of HBV enhancer I, extends completely around the circular viral genome, and ends just downstream of the unique polyadenylation site in HBV. In these animals, the viral mRNA is more abundant in centrilobular hepatocytes than elsewhere in the hepatic lobule. High-level viral DNA replication occurs inside viral nucleocapsid particles that preferentially form in the cytoplasm of these centrilobular hepatocytes, suggesting that an expression threshold must be reached for nucleocapsid assembly and viral replication to occur. Despite the restricted distribution of the viral replication machinery in centrilobular cytoplasmic nucleocapsids, nucleocapsid particles are detectable in the vast majority of hepatocyte nuclei throughout the hepatic lobule. The intranuclear nucleocapsid particles are empty, however, suggesting that viral nucleocapsid particle assembly occurs independently in the nucleus and the cytoplasm of the hepatocyte and implying that cytoplasmic nucleocapsid particles do not transport the viral genome across the nuclear membrane into the nucleus during the viral life cycle. This model creates the opportunity to examine the influence of viral and host factors on HBV pathogenesis and replication and to assess the antiviral potential of pharmacological agents and physiological processes, including the immune response. PMID:7666518

  9. High Level Information Fusion (HLIF) with nested fusion loops

    NASA Astrophysics Data System (ADS)

    Woodley, Robert; Gosnell, Michael; Fischer, Amber

    2013-05-01

    Situation modeling and threat prediction require higher levels of data fusion in order to provide actionable information. Beyond the sensor data and sources the analyst has access to, the use of out-sourced and re-sourced data is becoming common. Through the years, some common frameworks have emerged for dealing with information fusion—perhaps the most ubiquitous being the JDL Data Fusion Group and their initial 4-level data fusion model. Since these initial developments, numerous models of information fusion have emerged, hoping to better capture the human-centric process of data analyses within a machine-centric framework. 21st Century Systems, Inc. has developed Fusion with Uncertainty Reasoning using Nested Assessment Characterizer Elements (FURNACE) to address challenges of high level information fusion and handle bias, ambiguity, and uncertainty (BAU) for Situation Modeling, Threat Modeling, and Threat Prediction. It combines JDL fusion levels with nested fusion loops and state-of-the-art data reasoning. Initial research has shown that FURNACE is able to reduce BAU and improve the fusion process by allowing high level information fusion (HLIF) to affect lower levels without the double counting of information or other biasing issues. The initial FURNACE project was focused on the underlying algorithms to produce a fusion system able to handle BAU and repurposed data in a cohesive manner. FURNACE supports analyst's efforts to develop situation models, threat models, and threat predictions to increase situational awareness of the battlespace. FURNACE will not only revolutionize the military intelligence realm, but also benefit the larger homeland defense, law enforcement, and business intelligence markets.

  10. Starship 2040 Exhibit

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This photograph shows the Starship 2040 on display at Joe Davis Stadium in Huntsville, Alabama. Developed by the Space Transportation Directorate at Marshall Space Flight Center (MSFC), the Starship 2040 exhibit is housed in a 48-ft (14.6-m) tractor and trailer rig, permitting it to travel around the Nation, demonstrating NASA's vision of what commercial spaceflight might be like 40 years from now. All the irnovations suggested aboard the exhibit (automated vehicle health monitoring systems, high-energy propulsion drive, navigational aids, and emergency and safety systems) are based on concepts and technologies now being studied at NASA Centers and partner institutions around the Nation. NASA is the Nation's premier agency for development of the space transportation system, including future-generation reusable launch vehicles. Such systems, the keys to a 'real' Starship 2040, require revolutionary advances in critical aerospace technologies, from thermal, magnetic, chemical, and propellantless propulsion systems to new energy sources such as space solar power or antimatter propulsion. These and other advances are now being studied, developed, and tested at NASA field centers and partner institutions all over the Nation.

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

    SciTech Connect

    Farmer, J.C.; Van Konynenburg, R.A.; McCright, R.D. ); Bullen, D.B. )

    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.

  12. Spent nuclear fuel project high-level information management plan

    SciTech Connect

    Main, G.C.

    1996-09-13

    This document presents the results of the Spent Nuclear Fuel Project (SNFP) Information Management Planning Project (IMPP), a short-term project that identified information management (IM) issues and opportunities within the SNFP and outlined a high-level plan to address them. This high-level plan for the SNMFP IM focuses on specific examples from within the SNFP. The plan`s recommendations can be characterized in several ways. Some recommendations address specific challenges that the SNFP faces. Others form the basis for making smooth transitions in several important IM areas. Still others identify areas where further study and planning are indicated. The team`s knowledge of developments in the IM industry and at the Hanford Site were crucial in deciding where to recommend that the SNFP act and where they should wait for Site plans to be made. Because of the fast pace of the SNFP and demands on SNFP staff, input and interaction were primarily between the IMPP team and members of the SNFP Information Management Steering Committee (IMSC). Key input to the IMPP came from a workshop where IMSC members and their delegates developed a set of draft IM principles. These principles, described in Section 2, became the foundation for the recommendations found in the transition plan outlined in Section 5. Availability of SNFP staff was limited, so project documents were used as a basis for much of the work. The team, realizing that the status of the project and the environment are continually changing, tried to keep abreast of major developments since those documents were generated. To the extent possible, the information contained in this document is current as of the end of fiscal year (FY) 1995. Programs and organizations on the Hanford Site as a whole are trying to maximize their return on IM investments. They are coordinating IM activities and trying to leverage existing capabilities. However, the SNFP cannot just rely on Sitewide activities to meet its IM requirements

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

    SciTech Connect

    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 closure

  14. Crystalline plutonium hosts derived from high-level waste formulations.

    SciTech Connect

    O'Holleran, T. P.

    1998-04-24

    The Department of Energy has selected immobilization for disposal in a repository as one approach for disposing of excess plutonium (1). Materials for immobilizing weapons-grade plutonium for repository disposal must meet the ''spent fuel standard'' by providing a radiation field similar to spent fuel (2). Such a radiation field can be provided by incorporating fission products from high-level waste into the waste form. Experiments were performed to evaluate the feasibility of incorporating high-level waste (HLW) stored at the Idaho Chemical Processing Plant (ICPP) into plutonium dispositioning materials to meet the spent fuel standard. A variety of materials and preparation techniques were evaluated based on prior experience developing waste forms for immobilizing HLW. These included crystalline ceramic compositions prepared by conventional sintering and hot isostatic pressing (HIP), and glass formulations prepared by conventional melting. Because plutonium solubility in silicate melts is limited, glass formulations were intentionally devitrified to partition plutonium into crystalline host phases, thereby allowing increased overall plutonium loading. Samarium, added as a representative rare earth neutron absorber, also tended to partition into the plutonium host phases. Because the crystalline plutonium host phases are chemically more inert, the plutonium is more effectively isolated from the environment, and its attractiveness for proliferation is reduced. In the initial phase of evaluating each material and preparation method, cerium was used as a surrogate for plutonium. For promising materials, additional preparation experiments were performed using plutonium to verify the behavior of cerium as a surrogate. These experiments demonstrated that cerium performed well as a surrogate for plutonium. For the most part, cerium and plutonium partitioned onto the same crystalline phases, and no anomalous changes in oxidation state were observed. The only observed

  15. Interventions for Individuals With High Levels of Needle Fear

    PubMed Central

    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

  16. Evidence for the presence of R250G mutation at the ATPase domain of topoisomerase II in an arsenite-resistant Leishmania donovani exhibiting a differential drug inhibition profile.

    PubMed

    Singh, Gaganmeet; Thakur, Meghna; Chakraborti, Pradip K; Dey, Chinmoy S

    2009-01-01

    Resistance to operational drugs is a major barrier to successful antileishmanial chemotherapy that demands development of novel drug intervention strategies based on rational approaches. Model drug resistance phenotypes, such as arsenite resistance used in the current study, facilitate our understanding of the mechanism of drug resistance and assist in identifying new drug target(s). The current study was undertaken to investigate the sensitivity of topoisomerase II (topo II) of arsenite-sensitive (Ld-Wt) and -resistant (Ld-As20) Leishmania donovani to antileishmanial/anti-topo II agents. The effect of antileishmanial/anti-topo II drugs on partially purified topo II enzyme from Ld-Wt and Ld-As20 revealed differential inhibition of topo II decatenation activity for the two strains, with a lower amount of drug required to inhibit activity by 50% in Ld-Wt compared with Ld-As20. Comparison of topo II sequences from both strains indicated a point mutation, R250G, in the ATPase domain of the resistant strain. Furthermore, the Arg-250 of the ATPase domain of topo II was observed to be conserved throughout different species of Leishmania. Variation in the topo II gene sequence between Ld-Wt and Ld-As20 is envisaged to be responsible for the differential behaviour of the enzymes from the two sources. PMID:18805675

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

    SciTech Connect

    Mendel, J.E.

    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.

  18. Attenuation of high-level impulses by earmuffs.

    PubMed

    Zera, Jan; Mlynski, Rafal

    2007-10-01

    Attenuation of high-level acoustic impulses (noise reduction) by various types of earmuffs was measured using a laboratory source of type A impulses and an artificial test fixture compatible with the ISO 4869-3 standard. The measurements were made for impulses of peak sound-pressure levels (SPLs) from 150 to 170 dB. The rise time and A duration of the impulses depended on their SPL and were within a range of 12-400 mus (rise time) and 0.4-1.1 ms (A duration). The results showed that earmuff peak level attenuation increases by about 10 dB when the impulse's rise time and the A duration are reduced. The results also demonstrated that the signals under the earmuff cup have a longer rise and A duration than the original impulses recorded outside the earmuff. Results of the measurements were used to check the validity of various hearing damage risk criteria that specify the maximum permissible exposure to impulse noise. The present data lead to the conclusion that procedures in which hearing damage risk is assessed only from signal attenuation, without taking into consideration changes in the signal waveform under the earmuff, tend to underestimate the risk of hearing damage. PMID:17902846

  19. ATW system impact on high-level waste

    SciTech Connect

    Arthur, E.D.

    1992-12-01

    This report discusses the Accelerator Transmutation of Waste (ATW) concept which aims at destruction of key long-lived radionuclides in high-level nuclear waste (HLW), both fission products and actinides. This focus makes it different from most other transmutation concepts which concentrate primarily on actinide burning. The ATW system uses an accelerator-driven, sub-critical assembly to create an intense thermal neutron environment for radionuclide transmutation. This feature allows rapid transmutation under low-inventory system conditions, which in turn, has a direct impact on the size of chemical separations and materials handling components of the system. Inventories in ATW are factors of eight to thirty times smaller than reactor systems of equivalent thermal power. Chemical separations systems are relatively small in scale and can be optimized to achieve high decontamination factors and minimized waste streams. The low-inventory feature also directly impacts material amounts remaining in the system at its end of life. In addition to its low-inventory operation, the accelerator-driven neutron source features of ATW are key to providing a sufficient level of neutrons to allow transmutation of long-lived fission products.

  20. NOx AND HETEROGENEITY EFFECTS IN HIGH LEVEL WASTE (HLW)

    SciTech Connect

    Meisel, Dan; Camaioni, Donald M.; Orlando, Thom

    2000-06-01

    We summarize contributions from our EMSP supported research to several field operations of the Office of Environmental Management (EM). In particular we emphasize its impact on safety programs at the Hanford and other EM sites where storage, maintenance and handling of HLW is a major mission. In recent years we were engaged in coordinated efforts to understand the chemistry initiated by radiation in HLW. Three projects of the EMSP (''The NOx System in Nuclear Waste,'' ''Mechanisms and Kinetics of Organic Aging in High Level Nuclear Wastes, D. Camaioni--PI'' and ''Interfacial Radiolysis Effects in Tanks Waste, T. Orlando--PI'') were involved in that effort, which included a team at Argonne, later moved to the University of Notre Dame, and two teams at the Pacific Northwest National Laboratory. Much effort was invested in integrating the results of the scientific studies into the engineering operations via coordination meetings and participation in various stages of the resolution of some of the outstanding safety issues at the sites. However, in this Abstract we summarize the effort at Notre Dame.

  1. Cytotoxicity assessment of residual high-level disinfectants.

    PubMed

    Ryu, Mizuyuki; Kobayashi, Toshihiro; Kawamukai, Emiko; Quan, Glenlelyn; Furuta, Taro

    2013-01-01

    Some studies show the uptake of disinfectants on medical devices but no studies on their cytotoxicity have been reported. This study aimed to assess that cytotoxicity in a 3-dimensional culture system using HeLa cells grown in matrices composed of collagen. Plastic materials were soaked in the use solutions of the widely used high-level disinfectants, glutaraldehyde (GA), ortho-phthalaldehyde (OPA) and peracetic acid (PAA). After being rinsed, they were allowed to dry and were embedded into the cell medium to investigate the cytotoxicity of the residual disinfectants. Cytotoxicity was observed with the polyvinyl chloride, polyurethane and silicon tubes soaked in GA and OPA, indicating that both disinfectants were absorbed in the test pieces, whereas for PAA, none was observed. As for the polytetrafluoroethylene (PTFE) tubes, no disinfectant displayed cytotoxicity. GA and OPA are primary irritants, having a potential to cause anaphylaxis and other forms of allergic reactions. There should be consideration not only about the toxicity of the residual disinfectant from poor rinsing, but also about the toxicity that would result from the disinfectants that were absorbed and consequently released from the medical devices or materials.

  2. Wind resource quality affected by high levels of renewables

    DOE PAGES

    Diakov, Victor

    2015-06-17

    For solar photovoltaic (PV) and wind resources, the capacity factor is an important parameter describing the quality of the resource. As the share of variable renewable resources (such as PV and wind) on the electric system is increasing, so does curtailment (and the fraction of time when it cannot be avoided). At high levels of renewable generation, curtailments effectively change the practical measure of resource quality from capacity factor to the incremental capacity factor. The latter accounts only for generation during hours of no curtailment and is directly connected with the marginal capital cost of renewable generators for a givenmore » level of renewable generation during the year. The Western U.S. wind generation is analyzed hourly for a system with 75% of annual generation from wind, and it is found that the value for the system of resources with equal capacity factors can vary by a factor of 2, which highlights the importance of using the incremental capacity factor instead. Finally, the effect is expected to be more pronounced in smaller geographic areas (or when transmission limitations imposed) and less pronounced at lower levels of renewable energy in the system with less curtailment.« less

  3. Wind resource quality affected by high levels of renewables

    SciTech Connect

    Diakov, Victor

    2015-06-17

    For solar photovoltaic (PV) and wind resources, the capacity factor is an important parameter describing the quality of the resource. As the share of variable renewable resources (such as PV and wind) on the electric system is increasing, so does curtailment (and the fraction of time when it cannot be avoided). At high levels of renewable generation, curtailments effectively change the practical measure of resource quality from capacity factor to the incremental capacity factor. The latter accounts only for generation during hours of no curtailment and is directly connected with the marginal capital cost of renewable generators for a given level of renewable generation during the year. The Western U.S. wind generation is analyzed hourly for a system with 75% of annual generation from wind, and it is found that the value for the system of resources with equal capacity factors can vary by a factor of 2, which highlights the importance of using the incremental capacity factor instead. Finally, the effect is expected to be more pronounced in smaller geographic areas (or when transmission limitations imposed) and less pronounced at lower levels of renewable energy in the system with less curtailment.

  4. Pupil dilation dynamics track attention to high-level information.

    PubMed

    Kang, Olivia E; Huffer, Katherine E; Wheatley, Thalia P

    2014-01-01

    It has long been thought that the eyes index the inner workings of the mind. Consistent with this intuition, empirical research has demonstrated that pupils dilate as a consequence of attentional effort. Recently, Smallwood et al. (2011) demonstrated that pupil dilations not only provide an index of overall attentional effort, but are time-locked to stimulus changes during attention (but not during mind-wandering). This finding suggests that pupil dilations afford a dynamic readout of conscious information processing. However, because stimulus onsets in their study involved shifts in luminance as well as information, they could not determine whether this coupling of stimulus and pupillary dynamics reflected attention to low-level (luminance) or high-level (information) changes. Here, we replicated the methodology and findings of Smallwood et al. (2011) while controlling for luminance changes. When presented with isoluminant digit sequences, participants' pupillary dilations were synchronized with stimulus onsets when attending, but not when mind-wandering. This replicates Smallwood et al. (2011) and clarifies their finding by demonstrating that stimulus-pupil coupling reflects online cognitive processing beyond sensory gain.

  5. THERMAL ANALYSIS OF GEOLOGIC HIGH-LEVEL RADIOACTIVE WASTE PACKAGES

    SciTech Connect

    Hensel, S.; Lee, S.

    2010-04-20

    The engineering design of disposal of the high level waste (HLW) packages in a geologic repository requires a thermal analysis to provide the temperature history of the packages. Calculated temperatures are used to demonstrate compliance with criteria for waste acceptance into the geologic disposal gallery system and as input to assess the transient thermal characteristics of the vitrified HLW Package. The objective of the work was to evaluate the thermal performance of the supercontainer containing the vitrified HLW in a non-backfilled and unventilated underground disposal gallery. In order to achieve the objective, transient computational models for a geologic vitrified HLW package were developed by using a computational fluid dynamics method, and calculations for the HLW disposal gallery of the current Belgian geological repository reference design were performed. An initial two-dimensional model was used to conduct some parametric sensitivity studies to better understand the geologic system's thermal response. The effect of heat decay, number of co-disposed supercontainers, domain size, humidity, thermal conductivity and thermal emissivity were studied. Later, a more accurate three-dimensional model was developed by considering the conduction-convection cooling mechanism coupled with radiation, and the effect of the number of supercontainers (3, 4 and 8) was studied in more detail, as well as a bounding case with zero heat flux at both ends. The modeling methodology and results of the sensitivity studies will be presented.

  6. High levels of molecular chlorine in the Arctic atmosphere

    NASA Astrophysics Data System (ADS)

    Liao, Jin; Huey, L. Gregory; Liu, Zhen; Tanner, David J.; Cantrell, Chris A.; Orlando, John J.; Flocke, Frank M.; Shepson, Paul B.; Weinheimer, Andrew J.; Hall, Samuel R.; Ullmann, Kirk; Beine, Harry J.; Wang, Yuhang; Ingall, Ellery D.; Stephens, Chelsea R.; Hornbrook, Rebecca S.; Apel, Eric C.; Riemer, Daniel; Fried, Alan; Mauldin, Roy L.; Smith, James N.; Staebler, Ralf M.; Neuman, J. Andrew; Nowak, John B.

    2014-02-01

    Chlorine radicals can function as a strong atmospheric oxidant, particularly in polar regions, where levels of hydroxyl radicals are low. In the atmosphere, chlorine radicals expedite the degradation of methane and tropospheric ozone, and the oxidation of mercury to more toxic forms. Here we present direct measurements of molecular chlorine levels in the Arctic marine boundary layer in Barrow, Alaska, collected in the spring of 2009 over a six-week period using chemical ionization mass spectrometry. We report high levels of molecular chlorine, of up to 400 pptv. Concentrations peaked in the early morning and late afternoon, and fell to near-zero levels at night. Average daytime molecular chlorine levels were correlated with ozone concentrations, suggesting that sunlight and ozone are required for molecular chlorine formation. Using a time-dependent box model, we estimate that the chlorine radicals produced from the photolysis of molecular chlorine oxidized more methane than hydroxyl radicals, on average, and enhanced the abundance of short-lived peroxy radicals. Elevated hydroperoxyl radical levels, in turn, promoted the formation of hypobromous acid, which catalyses mercury oxidation and the breakdown of tropospheric ozone. We therefore suggest that molecular chlorine exerts a significant effect on the atmospheric chemistry of the Arctic.

  7. Why consider subseabed disposal of high-level nuclear waste

    SciTech Connect

    Heath, G. R.; Hollister, C. D.; Anderson, D. R.; Leinen, M.

    1980-01-01

    Large areas of the deep seabed warrant assessment as potential disposal sites for high-level radioactive waste because: (1) they are far from seismically and tectonically active lithospheric plate boundaries; (2) they are far from active or young volcanos; (3) they contain thick layers of very uniform fine-grained clays; (4) they are devoid of natural resources likely to be exploited in the forseeable future; (5) the geologic and oceanographic processes governing the deposition of sediments in such areas are well understood, and are remarkably insensitive to past oceanographic and climatic changes; and (6) sedmentary records of tens of millions of years of slow, uninterrupted deposition of fine grained clay support predictions of the future stability of such sites. Data accumulated to date on the permeability, ion-retardation properties, and mechanical strength of pelagic clay sediments indicate that they can act as a primary barrier to the escape of buried nuclides. Work in progress should determine within the current decade whether subseabed disposal is environmentally acceptable and technically feasible, as well as address the legal, political and social issues raised by this new concept.

  8. High-level PC-based laser system modeling

    NASA Astrophysics Data System (ADS)

    Taylor, Michael S.

    1991-05-01

    Since the inception of the Strategic Defense Initiative (SDI) there have been a multitude of comparison studies done in an attempt to evaluate the effectiveness and relative sizes of complementary, and sometimes competitive, laser weapon systems. It became more and more apparent that what the systems analyst needed was not only a fast, but a cost effective way to perform high-level trade studies. In the present investigation, a general procedure is presented for the development of PC-based algorithmic systems models for laser systems. This procedure points out all of the major issues that should be addressed in the design and development of such a model. Issues addressed include defining the problem to be modeled, defining a strategy for development, and finally, effective use of the model once developed. Being a general procedure, it will allow a systems analyst to develop a model to meet specific needs. To illustrate this method of model development, a description of the Strategic Defense Simulation - Design To (SDS-DT) model developed and used by Science Applications International Corporation (SAIC) is presented. SDS-DT is a menu-driven, fast executing, PC-based program that can be used to either calculate performance, weight, volume, and cost values for a particular design or, alternatively, to run parametrics on particular system parameters to perhaps optimize a design.

  9. Application of SYNROC to high-level defense wastes

    SciTech Connect

    Tewhey, J.D.; Hoenig, C.L.; Newkirk, H.W.; Rozsa, R.B.; Coles, D.G.; Ryerson, F.J.

    1981-01-01

    The SYNROC method for immobilization of high-level nuclear reactor wastes is currently being applied to US defense wastes in tank storage at Savannah River, South Carolina. The minerals zirconolite, perovskite, and hollandite are used in SYNROC D formulations to immobilize fission products and actinides that comprise up to 10% of defense waste sludges and coexisting solutions. Additional phases in SYNROC D are nepheline, the host phase for sodium; and spinel, the host for excess aluminum and iron. Up to 70 wt % of calcined sludge can be incorporated with 30 wt % of SYNROC additives to produce a waste form consisting of 10% nepheline, 30% spinel, and approximately 20% each of the radioactive waste-bearing phases. Urea coprecipitation and spray drying/calcining methods have been used in the laboratory to produce homogeneous, reactive ceramic powders. Hot pressing and sintering at temperatures from 1000 to 1100/sup 0/C result in waste form products with greater than 97% of theoretical density. Hot isostatic pressing has recently been implemented as a processing alternative. Characterization of waste-form mineralogy has been done by means of XRD, SEM, and electron microprobe. Leaching of SYNROC D samples is currently being carried out. Assessment of radiation damage effects and physical properties of SYNROC D will commence in FY 81.

  10. The GRAVITY instrument software/high-level software

    NASA Astrophysics Data System (ADS)

    Burtscher, Leonard; Wieprecht, Ekkehard; Ott, Thomas; Kok, Yitping; Yazici, Senol; Anugu, Narsireddy; Dembet, Roderick; Fedou, Pierre; Lacour, Sylvestre; Ott, Jürgen; Paumard, Thibaut; Lapeyrere, Vincent; Kervella, Pierre; Abuter, Roberto; Pozna, Eszter; Eisenhauer, Frank; Blind, Nicolas; Genzel, Reinhard; Gillessen, Stefan; Hans, Oliver; Haug, Marcus; Haussmann, Frank; Kellner, Stefan; Lippa, Magdalena; Pfuhl, Oliver; Sturm, Eckhard; Weber, Johannes; Amorim, Antonio; Brandner, Wolfgang; Rousselet-Perraut, Karine; Perrin, Guy S.; Straubmeier, Christian; Schöller, Markus

    2014-07-01

    GRAVITY is the four-beam, near-infrared, AO-assisted, fringe tracking, astrometric and imaging instrument for the Very Large Telescope Interferometer (VLTI). It is requiring the development of one of the most complex instrument software systems ever built for an ESO instrument. Apart from its many interfaces and interdependencies, one of the most challenging aspects is the overall performance and stability of this complex system. The three infrared detectors and the fast reflective memory network (RMN) recorder contribute a total data rate of up to 20 MiB/s accumulating to a maximum of 250 GiB of data per night. The detectors, the two instrument Local Control Units (LCUs) as well as the five LCUs running applications under TAC (Tools for Advanced Control) architecture, are interconnected with fast Ethernet, RMN fibers and dedicated fiber connections as well as signals for the time synchronization. Here we give a simplified overview of all subsystems of GRAVITY and their interfaces and discuss two examples of high-level applications during observations: the acquisition procedure and the gathering and merging of data to the final FITS file.

  11. High-Level Performance Modeling of SAR Systems

    NASA Technical Reports Server (NTRS)

    Chen, Curtis

    2006-01-01

    SAUSAGE (Still Another Utility for SAR Analysis that s General and Extensible) is a computer program for modeling (see figure) the performance of synthetic- aperture radar (SAR) or interferometric synthetic-aperture radar (InSAR or IFSAR) systems. The user is assumed to be familiar with the basic principles of SAR imaging and interferometry. Given design parameters (e.g., altitude, power, and bandwidth) that characterize a radar system, the software predicts various performance metrics (e.g., signal-to-noise ratio and resolution). SAUSAGE is intended to be a general software tool for quick, high-level evaluation of radar designs; it is not meant to capture all the subtleties, nuances, and particulars of specific systems. SAUSAGE was written to facilitate the exploration of engineering tradeoffs within the multidimensional space of design parameters. Typically, this space is examined through an iterative process of adjusting the values of the design parameters and examining the effects of the adjustments on the overall performance of the system at each iteration. The software is designed to be modular and extensible to enable consideration of a variety of operating modes and antenna beam patterns, including, for example, strip-map and spotlight SAR acquisitions, polarimetry, burst modes, and squinted geometries.

  12. Ultrafilter Conditions for High Level Waste Sludge Processing

    SciTech Connect

    Geeting, John GH; Hallen, Richard T.; Peterson, Reid A.

    2006-08-28

    An evaluation of the optimal filtration conditions was performed based on test data obtained from filtration of a High Level Waste Sludge sample from the Hanford tank farms. This evaluation was performed using the anticipated configuration for the Waste Treatment Plant at the Hanford site. Testing was performed to identify the optimal pressure drop and cross flow velocity for filtration at both high and low solids loading. However, this analysis indicates that the actual filtration rate achieved is relatively insensitive to these conditions under anticipated operating conditions. The maximum filter flux was obtained by adjusting the system control valve pressure from 400 to 650 kPa while the filter feed concentration increased from 5 to 20 wt%. However, operating the system with a constant control valve pressure drop of 500 kPa resulted in a less than 1% reduction in the average filter flux. Also note that allowing the control valve pressure to swing as much as +/- 20% resulted in less than a 5% decrease in filter flux.

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

    PubMed

    Aymanns, Simone; Mauerer, Stefanie; van Zandbergen, Ger; Wolz, Christiane; Spellerberg, Barbara

    2011-01-01

    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.

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

    SciTech Connect

    J.A. Ziegler

    2000-11-20

    The purpose of this calculation is to provide a dose consequence analysis of high-level waste (HLW) consisting of plutonium immobilized in vitrified HLW to be handled at the proposed Monitored Geologic Repository at Yucca Mountain for a beyond design basis event (BDBE) under expected conditions using best estimate values for each calculation parameter. In addition to the dose calculation, a plutonium respirable particle size for dose calculation use is derived. The current concept for this waste form is plutonium disks enclosed in cans immobilized in canisters of vitrified HLW (i.e., glass). The plutonium inventory at risk used for this calculation is selected from Plutonium Immobilization Project Input for Yucca Mountain Total Systems Performance Assessment (Shaw 1999). The BDBE examined in this calculation is a nonmechanistic initiating event and the sequence of events that follow to cause a radiological release. This analysis will provide the radiological releases and dose consequences for a postulated BDBE. Results may be considered in other analyses to determine or modify the safety classification and quality assurance level of repository structures, systems, and components. This calculation uses best available technical information because the BDBE frequency is very low (i.e., less than 1.0E-6 events/year) and is not required for License Application for the Monitored Geologic Repository. The results of this calculation will not be used as part of a licensing or design basis.

  15. The ALICE High Level Trigger: status and plans

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    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 the upgrade, during Run 2. For opportunistic use as a Grid computing site during periods of inactivity of the experiment a virtualisation based setup is deployed.

  16. The LHCb Data Acquisition and High Level Trigger Processing Architecture

    NASA Astrophysics Data System (ADS)

    Frank, M.; Gaspar, C.; Jost, B.; Neufeld, N.

    2015-12-01

    The LHCb experiment at the LHC accelerator at CERN collects collisions of particle bunches at 40 MHz. After a first level of hardware trigger with an output rate of 1 MHz, the physically interesting collisions are selected by running dedicated trigger algorithms in the High Level Trigger (HLT) computing farm. This farm consists of up to roughly 25000 CPU cores in roughly 1750 physical nodes each equipped with up to 4 TB local storage space. This work describes the LHCb online system with an emphasis on the developments implemented during the current long shutdown (LS1). We will elaborate the architecture to treble the available CPU power of the HLT farm and the technicalities to determine and verify precise calibration and alignment constants which are fed to the HLT event selection procedure. We will describe how the constants are fed into a two stage HLT event selection facility using extensively the local disk buffering capabilities on the worker nodes. With the installed disk buffers, the CPU resources can be used during periods of up to ten days without beams. These periods in the past accounted to more than 70% of the total time.

  17. Cytotoxicity assessment of residual high-level disinfectants.

    PubMed

    Ryu, Mizuyuki; Kobayashi, Toshihiro; Kawamukai, Emiko; Quan, Glenlelyn; Furuta, Taro

    2013-01-01

    Some studies show the uptake of disinfectants on medical devices but no studies on their cytotoxicity have been reported. This study aimed to assess that cytotoxicity in a 3-dimensional culture system using HeLa cells grown in matrices composed of collagen. Plastic materials were soaked in the use solutions of the widely used high-level disinfectants, glutaraldehyde (GA), ortho-phthalaldehyde (OPA) and peracetic acid (PAA). After being rinsed, they were allowed to dry and were embedded into the cell medium to investigate the cytotoxicity of the residual disinfectants. Cytotoxicity was observed with the polyvinyl chloride, polyurethane and silicon tubes soaked in GA and OPA, indicating that both disinfectants were absorbed in the test pieces, whereas for PAA, none was observed. As for the polytetrafluoroethylene (PTFE) tubes, no disinfectant displayed cytotoxicity. GA and OPA are primary irritants, having a potential to cause anaphylaxis and other forms of allergic reactions. There should be consideration not only about the toxicity of the residual disinfectant from poor rinsing, but also about the toxicity that would result from the disinfectants that were absorbed and consequently released from the medical devices or materials. PMID:24366628

  18. Anthropometric characteristics of high level European junior basketball players.

    PubMed

    Jelicić, M; Sekulić, D; Marinović, M

    2002-12-01

    The purpose of the research was to assess anthropometric status of European high-level junior basketball players and to determine anthropometric differences between the players playing in different game positions (guards, forwards, centers). The sample consisted of 132 young basketball players, participants of the European Junior Basketball Championship, Zadar, 2000. Participants were measured with 31 measures (anthropometric variables), on the basis of which two body composition measures (BMI and relative body fat) and somatotype were calculated. The basic statistical parameters were computed. The analysis of variance and discriminant canonical analysis were employed to determine the differences between positions in play. Results indicate that prominent longitudinal and transversal skeletal dimensions as well as circumference measures characterize players on the position of centers, but they do not have significantly larger skinfold measures in relation to forwards. Centers are also predominantly ectomorphic compared with other players. Guards achieved significantly lower values in all spaces and they are predominantly mesomorphic. Further investigations are necessary in order to assess potential changes in status of these parameters when the participants will reach the age of senior players and afterwards, as well as to determine relations between anthropometric status and skill related variables.

  19. Corrosion Behavior of Alloy 625 in Simulated Nuclear High-Level Waste Medium

    NASA Astrophysics Data System (ADS)

    Girija, S.; Nandakumar, T.; Mudali, U. Kamachi

    2015-11-01

    The present investigation aims to study the effect of various ions present in nuclear high-level waste (HLW) (acidic) medium on the corrosion resistance of Alloy 625, with solution-annealed and sensitized microstructure. The heat-affected zones are prone to sensitization during welding of components and subsequent exposure to acidic waste during service could result in intergranular corrosion in these regions and hence it was attempted to study the corrosion behavior of the alloy under sensitized conditions. Double loop electrochemical potentiokinetic reactivation test was carried out to obtain the extent of chromium depletion. Potentiodynamic anodic polarization and electrochemical noise investigations were carried out on Alloy 625 in 3 M nitric acid and simulated nuclear HLW medium (prepared in 3 M nitric acid) at 298 K and 323 K. The study showed that the alloy possess good corrosion resistance in 3 M nitric acid and simulated HLW medium. However, a marginal decrease in the corrosion resistance occurred in simulated HLW when compared to the plain acid, as observed from an increase in passivation current density, decrease in transpassive potentials, and decrease in electrochemical noise resistance. Increase in temperature of the medium and change in microstructure from solution-annealed to sensitized state further decreased the corrosion resistance of Alloy 625. Electrochemical noise time records obtained at open circuit conditions showed a stable passive film for 22 h of immersion of the alloy in 3 M nitric acid and simulated HLW. However, the amplitude of current fluctuations was higher for the sensitized microstructure when compared to the solution-annealed microstructure.

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

    SciTech Connect

    Gdowski, G.E.; Bullen, D.B. )

    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.

  1. Bean common mosaic virus Isolate Exhibits a Novel Pathogenicity Profile in Common Bean, Overcoming the bc-3 Resistance Allele Coding for the Mutated eIF4E Translation Initiation Factor.

    PubMed

    Feng, Xue; Myers, James R; Karasev, Alexander V

    2015-11-01

    Resistance against Bean common mosaic virus (BCMV) in Phaseolus vulgaris is governed by six recessive resistance alleles at four loci. One of these alleles, bc-3, is able to protect P. vulgaris against all BCMV strains and against other potyviruses; bc-3 was identified as the eIF4E allele carrying mutated eukaryotic translation initiation factor gene. Here, we characterized a novel BCMV isolate 1755a that was able to overcome bc-2 and bc-3 alleles in common bean. Thus, it displayed a novel pattern of interactions with resistance genes in P. vulgaris, and was assigned to a new pathogroup, PG-VIII. The IVT7214 cultivar supporting the replication of BCMV-1755a was found to have the intact homozygous bc-3 cleaved amplified polymorphic sequences marker and corresponding mutations in the eIF4E allele that confer resistance to BCMV isolates from all other pathogroups as well as to other potyviruses. The VPg protein of 1755a had seven amino acid substitutions relative to VPgs of other BCMV isolates unable to overcome bc-3. The 1755a genome was found to be a recombinant between NL1, US1 (both PG-I), and a yet unknown BCMV strain. Analysis of the recombination patterns in the genomes of NL1 and US1 (PG-I), NY15P (PG-V), US10 and RU1-OR (PG-VII), and 1755a (PG-VIII), indicated that P1/HC-Pro cistrons of BCMV strains may interact with most resistance genes. This is the first report of a BCMV isolate able to overcome the bc-3 resistance allele, suggesting that the virus has evolved mechanisms to overcome multiple resistance genes available in common bean. PMID:26196181

  2. A cost for high levels of sperm competition in rodents: increased sperm DNA fragmentation.

    PubMed

    delBarco-Trillo, Javier; García-Álvarez, Olga; Soler, Ana Josefa; Tourmente, Maximiliano; Garde, José Julián; Roldan, Eduardo R S

    2016-03-16

    Sperm competition, a prevalent evolutionary process in which the spermatozoa of two or more males compete for the fertilization of the same ovum, leads to morphological and physiological adaptations, including increases in energetic metabolism that may serve to propel sperm faster but that may have negative effects on DNA integrity. Sperm DNA damage is associated with reduced rates of fertilization, embryo and fetal loss, offspring mortality, and mutations leading to genetic disease. We tested whether high levels of sperm competition affect sperm DNA integrity. We evaluated sperm DNA integrity in 18 species of rodents that differ in their levels of sperm competition using the sperm chromatin structure assay. DNA integrity was assessed upon sperm collection, in response to incubation under capacitating or non-capacitating conditions, and after exposure to physical and chemical stressors. Sperm DNA was very resistant to physical and chemical stressors, whereas incubation in non-capacitating and capacitating conditions resulted in only a small increase in sperm DNA damage. Importantly, levels of sperm competition were positively associated with sperm DNA fragmentation across rodent species. This is the first evidence showing that high levels of sperm competition lead to an important cost in the form of increased sperm DNA damage.

  3. Stability of High-Level Radioactive Waste Forms

    SciTech Connect

    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 proposal

  4. High-level waste issues and resolutions document

    SciTech Connect

    Not Available

    1994-05-01

    The High-Level Waste (HLW) Issues and Resolutions Document recognizes US Department of Energy (DOE) complex-wide HLW issues and offers potential corrective actions for resolving these issues. Westinghouse Management and Operations (M&O) Contractors are effectively managing HLW for the Department of Energy at four sites: Idaho National Engineering Laboratory (INEL), Savannah River Site (SRS), West Valley Demonstration Project (WVDP), and Hanford Reservation. Each site is at varying stages of processing HLW into a more manageable form. This HLW Issues and Resolutions Document identifies five primary issues that must be resolved in order to reach the long-term objective of HLW repository disposal. As the current M&O contractor at DOE`s most difficult waste problem sites, Westinghouse recognizes that they have the responsibility to help solve some of the complexes` HLW problems in a cost effective manner by encouraging the M&Os to work together by sharing expertise, eliminating duplicate efforts, and sharing best practices. Pending an action plan, Westinghouse M&Os will take the initiative on those corrective actions identified as the responsibility of an M&O. This document captures issues important to the management of HLW. The proposed resolutions contained within this document set the framework for the M&Os and DOE work cooperatively to develop an action plan to solve some of the major complex-wide problems. Dialogue will continue between the M&Os, DOE, and other regulatory agencies to work jointly toward the goal of storing, treating, and immobilizing HLW for disposal in an environmentally sound, safe, and cost effective manner.

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

    SciTech Connect

    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.

  6. Activity profile of high-level Australian lacrosse players.

    PubMed

    Polley, Chris S; Cormack, Stuart J; Gabbett, Tim J; Polglaze, Ted

    2015-01-01

    Despite lacrosse being one of the fastest growing team sports in the world, there is a paucity of information detailing the activity profile of high-level players. Microtechnology systems (global positioning systems and accelerometers) provide the opportunity to obtain detailed information on the activity profile in lacrosse. Therefore, this study aimed to analyze the activity profile of lacrosse match-play using microtechnology. Activity profile variables assessed relative to minutes of playing time included relative distance (meter per minute), distance spent standing (0-0.1 m·min), walking (0.2-1.7 m·min), jogging (1.8-3.2 m·min), running (3.3-5.6 m·min), sprinting (≥5.7 m·min), number of high, moderate, low accelerations and decelerations, and player load (PL per minute), calculated as the square root of the sum of the squared instantaneous rate of change in acceleration in 3 vectors (medio-lateral, anterior-posterior, and vertical). Activity was recorded from 14 lacrosse players over 4 matches during a national tournament. Players were separated into positions of attack, midfield, or defense. Differences (effect size [ES] ± 90% confidence interval) between positions and periods of play were considered likely positive when there was ≥75% likelihood of the difference exceeding an ES threshold of 0.2. Midfielders had likely covered higher (mean ± SD) meters per minute (100 ± 11) compared with attackers (87 ± 14; ES = 0.89 ± 1.04) and defenders (79 ± 14; ES = 1.54 ± 0.94) and more moderate and high accelerations and decelerations. Almost all variables across positions were reduced in quarter 4 compared with quarter 1. Coaches should accommodate for positional differences when preparing lacrosse players for competition. PMID:25264672

  7. Engineering neural systems for high-level problem solving.

    PubMed

    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

  8. Liver regeneration in rats administered high levels of carbohydrates.

    PubMed

    Gershbein, L L

    1976-01-01

    Partially hepatectomized male rats were administered high levels of carbohydrates by drinker, in a casein-cellulose synthetic medium and in a commercial meal over a period of 10 days after surgery and the amount of liver regenerating or the increment ascertained; representative hepatic glycogen changes were also followed. Of the carbohydrate solutions, 5% levulose, 5% levulose+5% glucose and 10% sucrose increased the extent of liver regeneration as was also the case with the synthetic diet suplemented with 30 and 60% glucose, 30 and 60% levulose, 30% levulose+30% glucose, 30% each of galactose and the arabinoglactan, Stractan and 60% each of sucrose, honey and unsulphured molasses. The liver increments and glycogen contents were in the control range for animals fed the synthetic diet containing 30% each of lactose, sorbitol, corn starch and raffinose pentahydrate, 5% ascorbic acid and 15% L-arabinose but the liver glycogen was depressed with 30% xylose, a diet which was poorly tolerated; 15% mannitol caused a decrease inthe increment. The incorporation of several sugars into the commercial rat meal, including xylose (11%), raffinose (15%), L-arabinose (8%), D-arabinose (5%), L-sorbose (17%), galactosamine (0.20%) and galactono-gamma-lactone (10%), led to little change over the control increments. In intact rats fed the synthetic diet containing 30% each of glucose, lactose, galactose, sucrose and levulose for an interval of 10 days, the wet and dry liver--body weight ratios were significantly elevated only with the last two sugars but liver glycogen was increased in each instance.

  9. Review of high-level waste form properties. [146 bibliographies

    SciTech Connect

    Rusin, J.M.

    1980-12-01

    This report is a review of waste form options for the immobilization of high-level-liquid wastes from the nuclear fuel cycle. This review covers the status of international research and development on waste forms as of May 1979. Although the emphasis in this report is on waste form properties, process parameters are discussed where they may affect final waste form properties. A summary table is provided listing properties of various nuclear waste form options. It is concluded that proposed waste forms have properties falling within a relatively narrow range. In regard to crystalline versus glass waste forms, the conclusion is that either glass of crystalline materials can be shown to have some advantage when a single property is considered; however, at this date no single waste form offers optimum properties over the entire range of characteristics investigated. A long-term effort has been applied to the development of glass and calcine waste forms. Several additional waste forms have enough promise to warrant continued research and development to bring their state of development up to that of glass and calcine. Synthetic minerals, the multibarrier approach with coated particles in a metal matrix, and high pressure-high temperature ceramics offer potential advantages and need further study. Although this report discusses waste form properties, the total waste management system should be considered in the final selection of a waste form option. Canister design, canister materials, overpacks, engineered barriers, and repository characteristics, as well as the waste form, affect the overall performance of a waste management system. These parameters were not considered in this comparison.

  10. Engineering neural systems for high-level problem solving.

    PubMed

    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

  11. High-level disinfection of gastrointestinal endoscope reprocessing

    PubMed Central

    Chiu, King-Wah; Lu, Lung-Sheng; Chiou, Shue-Shian

    2015-01-01

    High level disinfection (HLD) of the gastrointestinal (GI) endoscope is not simply a slogan, but rather is a form of experimental monitoring-based medicine. By definition, GI endoscopy is a semicritical medical device. Hence, such medical devices require major quality assurance for disinfection. And because many of these items are temperature sensitive, low-temperature chemical methods, such as liquid chemical germicide, must be used rather than steam sterilization. In summarizing guidelines for infection prevention and control for GI endoscopy, there are three important steps that must be highlighted: manual washing, HLD with automated endoscope reprocessor, and drying. Strict adherence to current guidelines is required because compared to any other medical device, the GI endoscope is associated with more outbreaks linked to inadequate cleaning or disinfecting during HLD. Both experimental evaluation on the surveillance bacterial cultures and in-use clinical results have shown that, the monitoring of the stringent processes to prevent and control infection is an essential component of the broader strategy to ensure the delivery of safe endoscopy services, because endoscope reprocessing is a multistep procedure involving numerous factors that can interfere with its efficacy. Based on our years of experience in the surveillance of culture monitoring of endoscopic reprocessing, we aim in this study to carefully describe what details require attention in the GI endoscopy disinfection and to share our experience so that patients can be provided with high quality and safe medical practices. Quality management encompasses all aspects of pre- and post-procedural care including the efficiency of the endoscopy unit and reprocessing area, as well as the endoscopic procedure itself. PMID:25699232

  12. High Levels of Molecular Chlorine found in the Arctic Atmosphere

    NASA Astrophysics Data System (ADS)

    Liao, J.; Huey, L. G.; Liu, Z.; Tanner, D.; Cantrell, C. A.; Orlando, J. J.; Flocke, F. M.; Shepson, P. B.; Weinheimer, A. J.; Hall, S. R.; Beine, H.; Wang, Y.; Ingall, E. D.; Thompson, C. R.; Hornbrook, R. S.; Apel, E. C.; Fried, A.; Mauldin, L.; Smith, J. N.; Staebler, R. M.; Neuman, J. A.; Nowak, J. B.

    2014-12-01

    Chlorine radicals are a strong atmospheric oxidant, particularly in polar regions where levels of hydroxyl radicals can be quite low. In the atmosphere, chlorine radicals expedite the degradation of methane and tropospheric ozone and the oxidation of mercury to more toxic forms. Here, we present direct measurements of molecular chlorine levels in the Arctic marine boundary layer in Barrow, Alaska, collected in the spring of 2009 over a six-week period using chemical ionization mass spectrometry. We detected high levels of molecular chlorine of up to 400 pptv. Concentrations peaked in the early morning and late afternoon and fell to near-zero levels at night. Average daytime molecular chlorine levels were correlated with ozone concentrations, suggesting that sunlight and ozone are required for molecular chlorine formation. Using a time-dependent box model, we estimated that the chlorine radicals produced from the photolysis of molecular chlorine on average oxidized more methane than hydroxyl radicals and enhanced the abundance of short-lived peroxy radicals. Elevated hydroperoxyl radical levels, in turn, promoted the formation of hypobromous acid, which catalyzed mercury oxidation and the breakdown of tropospheric ozone. Therefore, we propose that molecular chlorine exerts a significant effect on the atmospheric chemistry in the Arctic. While the formation mechanisms of molecular chlorine are not yet understood, the main potential sources of chlorine include snowpack, sea salt, and sea ice. There is recent evidence of molecular halogen (Br2 and Cl2) formation in the Arctic snowpack. The coverage and composition of the snow may control halogen chemistry in the Arctic. Changes of sea ice and snow cover in the changing climate may affect air-snow-ice interaction and have a significant impact on the levels of radicals, ozone, mercury and methane in the Arctic troposphere.

  13. Radiative Lifetimes for High Levels of Neutral Fe

    NASA Astrophysics Data System (ADS)

    Lawler, James E.; Den Hartog, E.; Guzman, A.

    2013-01-01

    New radiative lifetime measurements for ~ 50 high lying levels of Fe I are reported. Laboratory astrophysics faces a challenge to provide basic spectroscopic data, especially reliable atomic transition probabilities, in the IR region for abundance studies. The availability of HgCdTe (HAWAII) detector arrays has opened IR spectral regions for extensive new spectroscopic studies. The SDSS III APOGEE project in the H-Band is an important example which will penetrate the dust obscuring the Galactic bulge. APOGEE will survey elemental abundances of 100,000 red giant stars in the bulge, bar, disk, and halo of the Milky Way. Many stellar spectra in the H-Band are, as expected, dominated by transitions of Fe I. Most of these IR transitions connect high levels of Fe. Our program has started an effort to meet this challenge with new radiative lifetime measurements on high lying levels of Fe I using time resolved laser induced fluorescence (TRLIF). The TRLIF method is typically accurate to 5% and is efficient. Our goal is to combine these accurate, absolute radiative lifetimes with emission branching fractions [1] to determine log(gf) values of the highest quality for Fe I lines in the UV, visible, and IR. This method was used very successfully by O’Brian et al. [2] on lower levels of Fe I. This method is still the best available for all but very simple spectra for which ab-initio theory is more accurate. Supported by NSF grant AST-0907732. [1] Branching fractions are being measured by M. Ruffoni and J. C. Pickering at Imperial College London. [2] O'Brian, T. R., Wickliffe, M. E., Lawler, J. E., Whaling, W., & Brault, J. W. 1991, J. Opt. Soc. Am. B 8, 1185

  14. High-level disinfection of gastrointestinal endoscope reprocessing.

    PubMed

    Chiu, King-Wah; Lu, Lung-Sheng; Chiou, Shue-Shian

    2015-02-20

    High level disinfection (HLD) of the gastrointestinal (GI) endoscope is not simply a slogan, but rather is a form of experimental monitoring-based medicine. By definition, GI endoscopy is a semicritical medical device. Hence, such medical devices require major quality assurance for disinfection. And because many of these items are temperature sensitive, low-temperature chemical methods, such as liquid chemical germicide, must be used rather than steam sterilization. In summarizing guidelines for infection prevention and control for GI endoscopy, there are three important steps that must be highlighted: manual washing, HLD with automated endoscope reprocessor, and drying. Strict adherence to current guidelines is required because compared to any other medical device, the GI endoscope is associated with more outbreaks linked to inadequate cleaning or disinfecting during HLD. Both experimental evaluation on the surveillance bacterial cultures and in-use clinical results have shown that, the monitoring of the stringent processes to prevent and control infection is an essential component of the broader strategy to ensure the delivery of safe endoscopy services, because endoscope reprocessing is a multistep procedure involving numerous factors that can interfere with its efficacy. Based on our years of experience in the surveillance of culture monitoring of endoscopic reprocessing, we aim in this study to carefully describe what details require attention in the GI endoscopy disinfection and to share our experience so that patients can be provided with high quality and safe medical practices. Quality management encompasses all aspects of pre- and post-procedural care including the efficiency of the endoscopy unit and reprocessing area, as well as the endoscopic procedure itself.

  15. Activity profile of high-level Australian lacrosse players.

    PubMed

    Polley, Chris S; Cormack, Stuart J; Gabbett, Tim J; Polglaze, Ted

    2015-01-01

    Despite lacrosse being one of the fastest growing team sports in the world, there is a paucity of information detailing the activity profile of high-level players. Microtechnology systems (global positioning systems and accelerometers) provide the opportunity to obtain detailed information on the activity profile in lacrosse. Therefore, this study aimed to analyze the activity profile of lacrosse match-play using microtechnology. Activity profile variables assessed relative to minutes of playing time included relative distance (meter per minute), distance spent standing (0-0.1 m·min), walking (0.2-1.7 m·min), jogging (1.8-3.2 m·min), running (3.3-5.6 m·min), sprinting (≥5.7 m·min), number of high, moderate, low accelerations and decelerations, and player load (PL per minute), calculated as the square root of the sum of the squared instantaneous rate of change in acceleration in 3 vectors (medio-lateral, anterior-posterior, and vertical). Activity was recorded from 14 lacrosse players over 4 matches during a national tournament. Players were separated into positions of attack, midfield, or defense. Differences (effect size [ES] ± 90% confidence interval) between positions and periods of play were considered likely positive when there was ≥75% likelihood of the difference exceeding an ES threshold of 0.2. Midfielders had likely covered higher (mean ± SD) meters per minute (100 ± 11) compared with attackers (87 ± 14; ES = 0.89 ± 1.04) and defenders (79 ± 14; ES = 1.54 ± 0.94) and more moderate and high accelerations and decelerations. Almost all variables across positions were reduced in quarter 4 compared with quarter 1. Coaches should accommodate for positional differences when preparing lacrosse players for competition.

  16. High-level disinfection of gastrointestinal endoscope reprocessing.

    PubMed

    Chiu, King-Wah; Lu, Lung-Sheng; Chiou, Shue-Shian

    2015-02-20

    High level disinfection (HLD) of the gastrointestinal (GI) endoscope is not simply a slogan, but rather is a form of experimental monitoring-based medicine. By definition, GI endoscopy is a semicritical medical device. Hence, such medical devices require major quality assurance for disinfection. And because many of these items are temperature sensitive, low-temperature chemical methods, such as liquid chemical germicide, must be used rather than steam sterilization. In summarizing guidelines for infection prevention and control for GI endoscopy, there are three important steps that must be highlighted: manual washing, HLD with automated endoscope reprocessor, and drying. Strict adherence to current guidelines is required because compared to any other medical device, the GI endoscope is associated with more outbreaks linked to inadequate cleaning or disinfecting during HLD. Both experimental evaluation on the surveillance bacterial cultures and in-use clinical results have shown that, the monitoring of the stringent processes to prevent and control infection is an essential component of the broader strategy to ensure the delivery of safe endoscopy services, because endoscope reprocessing is a multistep procedure involving numerous factors that can interfere with its efficacy. Based on our years of experience in the surveillance of culture monitoring of endoscopic reprocessing, we aim in this study to carefully describe what details require attention in the GI endoscopy disinfection and to share our experience so that patients can be provided with high quality and safe medical practices. Quality management encompasses all aspects of pre- and post-procedural care including the efficiency of the endoscopy unit and reprocessing area, as well as the endoscopic procedure itself. PMID:25699232

  17. Engineering Escherichia coli for high-level production of propionate.

    PubMed

    Akawi, Lamees; Srirangan, Kajan; Liu, Xuejia; Moo-Young, Murray; Perry Chou, C

    2015-07-01

    Mounting environmental concerns associated with the use of petroleum-based chemical manufacturing practices has generated significant interest in the development of biological alternatives for the production of propionate. However, biological platforms for propionate production have been limited to strict anaerobes, such as Propionibacteria and select Clostridia. In this work, we demonstrated high-level heterologous production of propionate under microaerobic conditions in engineered Escherichia coli. Activation of the native Sleeping beauty mutase (Sbm) operon not only transformed E. coli to be propionogenic (i.e., propionate-producing) but also introduced an intracellular "flux competition" between the traditional C2-fermentative pathway and the novel C3-fermentative pathway. Dissimilation of the major carbon source of glycerol was identified to critically affect such "flux competition" and, therefore, propionate synthesis. As a result, the propionogenic E. coli was further engineered by inactivation or overexpression of various genes involved in the glycerol dissimilation pathways and their individual genetic effects on propionate production were investigated. Generally, knocking out genes involved in glycerol dissimilation (except glpA) can minimize levels of solventogenesis and shift more dissimilated carbon flux toward the C3-fermentative pathway. For optimal propionate production with high C3:C2-fermentative product ratios, glycerol dissimilation should be channeled through the respiratory pathway and, upon suppressed solventogenesis with minimal production of highly reduced alcohols, the alternative NADH-consuming route associated with propionate synthesis can be critical for more flexible redox balancing. With the implementation of various biochemical and genetic strategies, high propionate titers of more than 11 g/L with high yields up to 0.4 g-propionate/g-glycerol (accounting for ~50 % of dissimilated glycerol) were achieved, demonstrating the

  18. Hydrothermal transformations in an aluminophosphate glass matrix containing simulators of high-level radioactive wastes

    NASA Astrophysics Data System (ADS)

    Yudintsev, S. V.; Mal'kovsky, V. I.; Mokhov, A. V.

    2016-05-01

    The interaction of aluminophosphate glass with water at 95°C for 35 days results in glass heterogenization and in the appearance of a gel layer and various phases. The leaching rate of elements is low owing to the formation of a protective layer on the glass surface. It is shown that over 80% of uranium leached from the glass matrix occurs as colloids below 450 nm in size characterized by high migration ability in the geological environment. To determine the composition of these colloids is a primary task for further studies. Water vapor is a crystallization factor for glasses. The conditions as such may appear even at early stages of glass storage because of the failure of seals on containers of high-level radioactive wastes. The examination of water resistance of crystallized matrices and determination of the fraction of radionuclide in colloids are also subjects for further studies.

  19. Increasing Safety and Reducing Environmental Damage Risk from Aging High-Level Radioactive Waste Tanks

    SciTech Connect

    Steffler, Eric D.; McClintock, Frank A.; Lam, Poh-Sang; Lloyd, W. R.; Rashid, Mark M.

    2004-06-01

    The research activities of this EMSP project at the U. S. Department of Energy Savannah River Site (SRS) are developed for the site-specific needs in the area of high level nuclear waste tanks. Traditional and advanced fracture methodologies are assessed, the crack growth resistance properties for the material of construction (A285 carbon steel) are measured in terms of crack tip constraint, crack growth criteria based on crack opening displacement (CTOD) or angle (CTOA) are developed, and the relationship between stress corrosion cracking (SCC) and the weld residual stress is investigated. All these activities lead to the development of predictive tools for the structural integrity of the SRS waste tanks. The methodologies can be extended to commercial applications.

  20. Development of a pelleted waste form for high-level alumina wastes

    SciTech Connect

    Kirkbride, R.A.

    1980-09-01

    A formulation to pelletize simulated high-level ICPP alumina waste calcine was developed. The pellets are formed on a 41-cm-diameter disc pelletizer using 5% bentonite, 2% metakaolin, and 5 wt % calcium hydroxide as a solid binder and a solution of 7M phosphoric acid and 4M nitric acid as a liquid binder. After drying and heat treatment at 800/sup 0/C for 2 hours, the average crush strength of the pellets is 3.9 MPa and the pellets have a leach resistance of 10/sup -3/ g/cm/sup 2//day, based on Soxhlet leaching for 48 h at 95/sup 0/C with distilled water.

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

    SciTech Connect

    Strum, M.J.; Weiss, H.; Farmer, J.C. ); Bullen, D.B. )

    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.

  2. Multibarrier copper-base containers for high-level waste disposal

    SciTech Connect

    Peters, D.T. ); Medley, D.F. ); Enders, P.A. ); Kundig, K.J.A.

    1993-11-01

    Copper and aluminum bronze have been shown to exhibit a high degree of kinetic stability in anticipated repository environments, including mildly oxidizing conditions under high gamma fields. The nature of the thermodynamic and kinetic stability of the metals is discussed. It is proposed that a robust, composite waste container composed of a copper mantle surrounding an inner shell of high-strength aluminum bronze would make the best use of the corrosion- and creep-related properties of the metals. Several designs and closure techniques are suggested. A bimetallic, centrifugally cast cylinder with a diameter and wall thickness appropriate to a high-level waste burial container has been produced. The advantages of the bimetallic casting are discussed, as are the potential multifunctional applications of composite containers of this type. Suggestions for future work are proposed. Creation of an engineered analog is suggested as an additional redundant safeguard in the proposed repository.

  3. Development of Concentration and Calcination Technology For High Level Liquid Waste

    SciTech Connect

    Pande, D.P.

    2006-07-01

    The concentrated medium and high-level liquid radio chemicals effluents contain nitric acid, water along with the dissolved chemicals including the nitrates of the radio nuclides. High level liquid waste contain mainly nitrates of cesium, strontium, cerium, zirconium, chromium, barium, calcium, cobalt, copper, pickle, iron etc. and other fission products. This concentrated solution requires further evaporation, dehydration, drying and decomposition in temperature range of 150 to 700 deg. C. The addition of the calcined solids in vitrification pot, instead of liquid feed, helps to avoid low temperature zone because the vaporization of the liquid and decomposition of nitrates do not take place inside the melter. In our work Differential and thermo gravimetric studies has been carried out in the various stages of thermal treatment including drying, dehydration and conversion to oxide forms. Experimental studies were done to characterize the chemicals present in high-level radioactive waste. A Rotary Ball Kiln Calciner was used for development of the process because this is amenable for continuous operation and moderately good heat transfer can be achieved inside the kiln. This also has minimum secondary waste and off gases generation. The Rotary Ball Kiln Calciner Demonstration facility system was designed and installed for the demonstration of calcination process. The Rotary Ball Kiln Calciner is a slowly rotating slightly inclined horizontal tube that is externally heated by means of electric resistance heating. The liquid feed is sprayed onto the moving bed of metal balls in a slowly rotating calciner by a peristaltic type-metering pump. The vaporization of the liquid occurs in the pre-calcination zone due to counter current flow of hot gases. The dehydration and denitration of the solids occurs in the calcination zone, which is externally heated by electrical furnace. The calcined powder is cooled in the post calcination portion. It has been demonstrated that the

  4. High level waste interim storge architecture selection - decision report

    SciTech Connect

    Calmus, R.B.

    1996-09-27

    The U.S. Department of Energy (DOE) has embarked upon a course to acquire Hanford Site tank waste treatment and immobilization services using privatized facilities (RL 1996a). This plan contains a two-phased approach. Phase I is a proof-of-principle/connnercial demonstration- scale effort and Phase II is a fiill-scale production effort. In accordance with the planned approach, interim storage and disposal of various products from privatized facilities are to be DOE fumished. The high-level waste (BLW) interim storage options, or alternative architectures, were identified and evaluated to provide the framework from which to select the most viable method of Phase I BLW interim storage (Calmus 1996). This evaluation, hereafter referred to as the Alternative Architecture Evaluation, was performed to established performance and risk criteria (technical merit, cost, schedule, etc.). Based on evaluation results, preliminary architectures and path forward reconunendations were provided for consideration in the architecture decision- maldng process. The decision-making process used for selection of a Phase I solidified BLW interim storage architecture was conducted in accordance with an approved Decision Plan (see the attachment). This decision process was based on TSEP-07,Decision Management Procedure (WHC 1995). The established decision process entailed a Decision Board, consisting of Westinghouse Hanford Company (VY`HC) management staff, and included appointment of a VTHC Decision Maker. The Alternative Architecture Evaluation results and preliminary recommendations were presented to the Decision Board members for their consideration in the decision-making process. The Alternative Architecture Evaluation was prepared and issued before issuance of @C-IP- 123 1, Alternatives Generation and Analysis Procedure (WI-IC 1996a), but was deemed by the Board to fully meet the intent of WHC-IP-1231. The Decision Board members concurred with the bulk of the Alternative Architecture

  5. JET MIXING ANALYSIS FOR SRS HIGH-LEVEL WASTE RECOVERY

    SciTech Connect

    Lee, S.

    2011-07-05

    The process of recovering the waste in storage tanks at the Savannah River Site (SRS) typically requires mixing the contents of the tank to ensure uniformity of the discharge stream. Mixing is accomplished with one to four slurry pumps located within the tank liquid. The slurry pump may be fixed in position or they may rotate depending on the specific mixing requirements. The high-level waste in Tank 48 contains insoluble solids in the form of potassium tetraphenyl borate compounds (KTPB), monosodium titanate (MST), and sludge. Tank 48 is equipped with 4 slurry pumps, which are intended to suspend the insoluble solids prior to transfer of the waste to the Fluidized Bed Steam Reformer (FBSR) process. The FBSR process is being designed for a normal feed of 3.05 wt% insoluble solids. A chemical characterization study has shown the insoluble solids concentration is approximately 3.05 wt% when well-mixed. The project is requesting a Computational Fluid Dynamics (CFD) mixing study from SRNL to determine the solids behavior with 2, 3, and 4 slurry pumps in operation and an estimate of the insoluble solids concentration at the suction of the transfer pump to the FBSR process. The impact of cooling coils is not considered in the current work. The work consists of two principal objectives by taking a CFD approach: (1) To estimate insoluble solids concentration transferred from Tank 48 to the Waste Feed Tank in the FBSR process and (2) To assess the impact of different combinations of four slurry pumps on insoluble solids suspension and mixing in Tank 48. For this work, several different combinations of a maximum of four pumps are considered to determine the resulting flow patterns and local flow velocities which are thought to be associated with sludge particle mixing. Two different elevations of pump nozzles are used for an assessment of the flow patterns on the tank mixing. Pump design and operating parameters used for the analysis are summarized in Table 1. The baseline

  6. High-level microsatellite instability in appendiceal carcinomas.

    PubMed

    Taggart, Melissa W; Galbincea, John; Mansfield, Paul F; Fournier, Keith F; Royal, Richard E; Overman, Michael J; Rashid, Asif; Abraham, Susan C

    2013-08-01

    High-level microsatellite instability (MSI-high) is found in approximately 15% of all colorectal adenocarcinomas (CRCs) and in at least 20% of right-sided cancers. It is most commonly due to somatic hypermethylation of the MLH1 gene promoter region, with familial cases (Lynch syndrome) representing only 2% to 3% of CRCs overall. In contrast to CRC, MSI-high in appendiceal adenocarcinomas is rare. Only 4 MSI-high appendiceal carcinomas and 1 MSI-high appendiceal serrated adenoma have been previously reported, and the prevalence of MSI in the appendix is unknown. We identified 108 appendiceal carcinomas from MD Anderson Cancer Center in which MSI status had been assessed by immunohistochemistry for the DNA mismatch-repair proteins MLH1, MSH2, MSH6, and PMS2 (n=83), polymerase chain reaction (n=7), or both (n=18). Three cases (2.8%) were MSI-high, and 1 was MSI-low. The 3 MSI-high cases included: (1) a poorly differentiated nonmucinous adenocarcinoma with loss of MLH1/PMS2 expression, lack of MLH1 promoter methylation, and lack of BRAF gene mutation, but no detected germline mutation in MLH1 from a 39-year-old man; (2) an undifferentiated carcinoma with loss of MSH2/MSH6, but no detected germline mutation in MSH2 or TACSTD1, from a 59-year-old woman; and (3) a moderately differentiated mucinous adenocarcinoma arising in a villous adenoma with loss of MSH2/MSH6 expression, in a 38-year-old man with a strong family history of CRC who declined germline testing. When the overall group of appendiceal carcinomas was classified according to histologic features and precursor lesions, the frequencies of MSI-high were: 3 of 108 (2.8%) invasive carcinomas, 3 of 96 (3.1%) invasive carcinomas that did not arise from a background of goblet cell carcinoid tumors, and 0 of 12 (0%) signet ring and mucinous carcinomas arising in goblet cell carcinoid tumors. These findings, in conjunction with the previously reported MSI-high appendiceal carcinomas, highlight the low prevalence of MSI

  7. Reusable, Extensible High-Level Data-Distribution Concept

    NASA Technical Reports Server (NTRS)

    James, Mark; Zima, Hans; Diaconescua, Roxana

    2007-01-01

    A framework for high-level specification of data distributions in data-parallel application programs has been conceived. [As used here, distributions signifies means to express locality (more specifically, locations of specified pieces of data) in a computing system composed of many processor and memory components connected by a network.] Inasmuch as distributions exert a great effect on the performances of application programs, it is important that a distribution strategy be flexible, so that distributions can be adapted to the requirements of those programs. At the same time, for the sake of productivity in programming and execution, it is desirable that users be shielded from such error-prone, tedious details as those of communication and synchronization. As desired, the present framework enables a user to refine a distribution type and adjust it to optimize the performance of an application program and conceals, from the user, the low-level details of communication and synchronization. The framework provides for a reusable, extensible, data-distribution design, denoted the design pattern, that is independent of a concrete implementation. The design pattern abstracts over coding patterns that have been found to be commonly encountered in both manually and automatically generated distributed parallel programs. The following description of the present framework is necessarily oversimplified to fit within the space available for this article. Distributions are among the elements of a conceptual data-distribution machinery, some of the other elements being denoted domains, index sets, and data collections (see figure). Associated with each domain is one index set and one distribution. A distribution class interface (where "class" is used in the object-oriented-programming sense) includes operations that enable specification of the mapping of an index to a unit of locality. Thus, "Map(Index)" specifies a unit, while "LocalLayout(Index)" specifies the local address

  8. Phylogeographic reconstruction of a bacterial species with high levels of lateral gene transfer

    USGS Publications Warehouse

    Pearson, T.; Giffard, P.; Beckstrom-Sternberg, S.; Auerbach, R.; Hornstra, H.; Tuanyok, A.; Price, E.P.; Glass, M.B.; Leadem, B.; Beckstrom-Sternberg, J. S.; Allan, G.J.; Foster, J.T.; Wagner, D.M.; Okinaka, R.T.; Sim, S.H.; Pearson, O.; Wu, Z.; Chang, J.; Kaul, R.; Hoffmaster, A.R.; Brettin, T.S.; Robison, R.A.; Mayo, M.; Gee, J.E.; Tan, P.; Currie, B.J.; Keim, P.

    2009-01-01

    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. Conclusion: We describe an

  9. Cementitious Grout for Closing SRS High Level Waste Tanks - 12315

    SciTech Connect

    Langton, C.A.; Stefanko, D.B.; Burns, H.H.; Waymer, J.; Mhyre, W.B.; Herbert, J.E.; Jolly, J.C. Jr.

    2012-07-01

    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. Ancillary equipment abandoned in the tanks will also be filled to the extent practical. 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 to be chemically reducing with a reduction potential (Eh) of -200 to -400. Grouts with this chemistry stabilize 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 to support the mass placement strategy developed by

  10. Advanced High-Level Waste Glass Research and Development Plan

    SciTech Connect

    Peeler, David K.; Vienna, John D.; Schweiger, Michael J.; Fox, Kevin M.

    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

  11. Development of Crystal-Tolerant High-Level Waste Glasses

    SciTech Connect

    Matyas, Josef; Vienna, John D.; Schaible, Micah J.; Rodriguez, Carmen P.; Crum, Jarrod V.; Arrigoni, Alyssa L.; Tate, Rachel M.

    2010-12-17

    Twenty five glasses were formulated. They were batched from HLW AZ-101 simulant or raw chemicals and melted and tested with a series of tests to elucidate the effect of spinel-forming components (Ni, Fe, Cr, Mn, and Zn), Al, and noble metals (Rh2O3 and RuO2) on the accumulation rate of spinel crystals in the glass discharge riser of the high-level waste (HLW) melter. In addition, the processing properties of glasses, such as the viscosity and TL, were measured as a function of temperature and composition. Furthermore, the settling of spinel crystals in transparent low-viscosity fluids was studied at room temperature to access the shape factor and hindered settling coefficient of spinel crystals in the Stokes equation. The experimental results suggest that Ni is the most troublesome component of all the studied spinel-forming components producing settling layers of up to 10.5 mm in just 20 days in Ni-rich glasses if noble metals or a higher concentration of Fe was not introduced in the glass. The layer of this thickness can potentially plug the bottom of the riser, preventing glass from being discharged from the melter. The noble metals, Fe, and Al were the components that significantly slowed down or stopped the accumulation of spinel at the bottom. Particles of Rh2O3 and RuO2, hematite and nepheline, acted as nucleation sites significantly increasing the number of crystals and therefore decreasing the average crystal size. The settling rate of ≤10-μm crystal size around the settling velocity of crystals was too low to produce thick layers. The experimental data for the thickness of settled layers in the glasses prepared from AZ-101 simulant were used to build a linear empirical model that can predict crystal accumulation in the riser of the melter as a function of concentration of spinel-forming components in glass. The developed model predicts the thicknesses of accumulated layers quite well, R2 = 0.985, and can be become an efficient tool for the formulation

  12. Hanford high-level waste evaporator/crystallizer corrosion evaluation

    SciTech Connect

    Ohl, P.C.; Carlos, W.C.

    1993-10-01

    The US Department of Energy, Hanford Site nuclear reservation, located in Southeastern Washington State, is currently home to 61 Mgal of radioactive waste stored in 177 large underground storage tanks. As an intermediate waste volume reduction, the 242-A Evaporator/Crystallizer processes waste solutions from most of the operating laboratories and plants on the Hanford Site. The waste solutions are concentrated in the Evaporator/Crystallizer to a slurry of liquid and crystallized salts. This concentrated slurry is returned to Hanford Site waste tanks at a significantly reduced volume. The Washington State Department of Ecology Dangerous Waste Regulations, WAC 173-393 require that a tank system integrity assessment be completed and maintained on file at the facility for all dangerous waste tank systems. This corrosion evaluation was performed in support of the 242-A Evaporator/Crystallizer Tank System Integrity Assessment Report. This corrosion evaluation provided a comprehensive compatibility study of the component materials and corrosive environments. Materials used for the Evaporator components and piping include austenitic stainless steels (SS) (primarily ASTM A240, Type 304L) and low alloy carbon steels (CS) (primarily ASTM A53 and A106) with polymeric or asbestos gaskets at flanged connections. Building structure and secondary containment is made from ACI 301-72 Structural Concrete for Buildings and coated with a chemically resistant acrylic coating system.

  13. Insecticide resistance status of Colorado potato beetle (Coleoptera: Chrysomelidae) adults in northern Xinjiang Uygur autonomous region.

    PubMed

    Jiang, Wei-Hua; Wang, Zhi-Tian; Xiong, Man-Hui; Lu, Wei-Ping; Liu, Ping; Guo, Wen-Chao; Li, Guo-Qing

    2010-08-01

    Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), has become the economically most important insect defoliator of potatoes, Solanum tuberosum L., in northern Xinjiang Uygur autonomous region in China. Currently, control of Colorado potato beetle relies mainly on chemical insecticides. And this may result in insecticide resistance. In this study, LD50 values were measured by a topical bioassay for 14 conventional insecticides in seven local populations from Urumqi, Changji, Tacheng, Nilka, Gongliu, Qapqal, and Tekes counties (cities). The Tekes field population was the most susceptible population and was selected as a reference strain. Compared with the Tekes strain, the Changji, Qapqal, Nilka, Tacheng, and Gongliu populations exhibited moderate to very high levels of resistance to cyhalothrin. The Qapqal and Changji populations showed a moderate and a very high resistance to deltamethrin, respectively. And the Changji population developed a high resistance against alpha-cypermethrin. Moreover, the Qapqal population had a moderate resistance to carbofuran, and the Urumqi population reached high level of resistance to endosulfan. Possible resistance mechanisms of the Changji and Qapqal populations were determined using three enzyme inhibitors. Triphenyl phosphate (TPP), diethylmeleate, and piperonyl butoxide (PBO) had little synergism to cyhalothrin in the two populations. In contrast, PBO and TPP exhibited some synergistic effects to carbofuran in the Qapqal population, indicating the involvement of monooxygenases and esterases in conferring carbofuran resistance. It seems that additional mechanisms, such as target site insensitivity, should play an important role in Colorado potato beetle resistances to cyhalothrin and carbofuran in northern Xinjiang local populations.

  14. Anticipated Degradation Modes of Metallic Engineered Barriers for High-Level Nuclear Waste Repositories

    NASA Astrophysics Data System (ADS)

    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.

  15. High-level waste program progress report, April 1, 1980-June 30, 1980

    SciTech Connect

    1980-08-01

    The highlights of this report are on: waste management analysis for nuclear fuel cycles; fixation of waste in concrete; study of ceramic and cermet waste forms; alternative high-level waste forms development; and high-level waste container development.

  16. Validation of Stress Corrosion Cracking Model for High Level Radioactive-Waste Packages

    SciTech Connect

    Lu, S; Gordon, G; Andresen, P

    2004-04-22

    A stress corrosion cracking (SCC) model has been adapted for performance prediction of high level radioactive-waste packages to be emplaced in the proposed Yucca Mountain radioactive-waste repository. SCC is one form of environmentally assisted cracking resulting from the presence of three factors: metallurgical susceptibility, critical environment, and tensile stresses. For waste packages of the proposed Yucca Mountain repository, the outer barrier material is the highly corrosion-resistant Alloy UNS-N06022, the environment is represented by the water film present on the surface of the waste package from dripping or deliquescence of soluble salts present in any surface deposits, and the stress is principally the weld induced residual stress. SCC has historically been separated into 'initiation' and 'propagation' phases. Initiation of SCC will not occur on a smooth surface if the surface stress is below a threshold value defined as the threshold stress. Cracks can also initiate at and propagate from flaws (or defects) resulting from manufacturing processes (such as welding). To account for crack propagation, the slip dissolution/film rupture (SDFR) model is adopted to provide mathematical formulae for prediction of the crack growth rate. Once the crack growth rate at an initiated SCC is determined, it can be used by the performance assessment (not in the scope of this paper) to determine the time to through-wall penetration for the waste package. This paper presents the development and validation of the SDFR crack growth rate model based on technical information in the literature as well as experimentally determined crack growth rates developed specifically for Alloy UNS- N06022 in environments relevant to high level radioactive-waste packages of the proposed Yucca Mountain radioactive-waste repository.

  17. International program to study subseabed disposal of high-level radioactive wastes

    SciTech Connect

    Carlin, E.M.; Hinga, K.R.; Knauss, J.A.

    1984-01-01

    This report provides an overview of the international program to study seabed disposal of nuclear wastes. Its purpose is to inform legislators, other policy makers, and the general public as to the history of the program, technological requirements necessary for feasibility assessment, legal questions involved, international coordination of research, national policies, and research and development activities. Each of these major aspects of the program is presented in a separate section. The objective of seabed burial, similar to its continental counterparts, is to contain and to isolate the wastes. The subseabed option should not be confuesed with past practices of ocean dumping which have introduced wastes into ocean waters. Seabed disposal refers to the emplacement of solidified high-level radioactive waste (with or without reprocessing) in certain geologically stable sediments of the deep ocean floor. Specially designed surface ships would transport waste canisters from a port facility to the disposal site. Canisters would be buried from a few tens to a few hundreds of meters below the surface of ocean bottom sediments, and hence would not be in contact with the overlying ocean water. The concept is a multi-barrier approach for disposal. Barriers, including waste form, canister, ad deep ocean sediments, will separate wastes from the ocean environment. High-level wastes (HLW) would be stabilized by conversion into a leach-resistant solid form such as glass. This solid would be placed inside a metallic canister or other type of package which represents a second barrier. The deep ocean sediments, a third barrier, are discussed in the Feasibility Assessment section. The waste form and canister would provide a barrier for several hundred years, and the sediments would be relied upon as a barrier for thousands of years. 62 references, 3 figures, 2 tables.

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

    SciTech Connect

    Gdowski, G.E.; Bullen, D.B. )

    1988-08-01

    Six alloys are being considered as possible materials for the fabrication of containers for the disposal of high-level radioactive waste. Three of these candidate materials are copper-based alloys: CDA 102 (oxygen-free copper), CDA 613 (Cu-7Al), and CDA 715 (Cu-30Ni). The other three are iron- to nickel-based austenitic materials: Types 304L and 316L stainless steels and Alloy 825. Radioactive waste will include spent-fuel assemblies from reactors as well as waste in borosilicate glass and will be sent to the prospective site at Yucca Mountain, Nevada, for disposal. The waste-package 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, the containers must be retrievable from the disposal site. Shortly after emplacement of the containers in the repository, they will be exposed to high temperatures and high gamma radiation fields from the decay of high-level waste. This radiation will promote the radiolytic decomposition of moist air to hydrogen. This volume surveys the available data on the effects of hydrogen on the six candidate alloys for fabrication of the containers. For copper, the mechanism of hydrogen embrittlement is discussed, and the effects of hydrogen on the mechanical properties of the copper-based alloys are reviewed. The solubilities and diffusivities of hydrogen are documented for these alloys. For the austenitic materials, the degradation of mechanical properties by hydrogen is documented. The diffusivity and solubility of hydrogen in these alloys are also presented. For the copper-based alloys, the ranking according to resistance to detrimental effects of hydrogen is: CDA 715 (best) > CDA 613 > CDA 102 (worst). For the austenitic alloys, the ranking is: Type 316L stainless steel {approx} Alloy 825 > Type 304L stainless steel (worst). 87 refs., 19 figs., 8 tabs.

  19. Mechanisms of resistance to paraquat in plants.

    PubMed

    Hawkes, Timothy R

    2014-09-01

    The aim of this brief review is to draw information from studies of the mechanism of evolved resistance in weeds, together with information from laboratory studies of paraquat tolerance in model plants. Plants having mutations that limit paraquat uptake into cytoplasm, that confer various stress tolerances or that have transgenes that co-express two or more of the chloroplast Halliwell-Asada cycle enzymes can all exhibit enhanced tolerance to paraquat. However, none of these mechanisms correspond to the high-level resistances that have evolved naturally in weeds. Most, but not all, of the evidence from studies of paraquat-resistant biotypes of weeds can reasonably be reconciled with the proposal of a single major gene mechanism that sequesters paraquat away from chloroplasts and into the vacuole. However, the molecular details of this putative mechanism remain ill-defined.

  20. Effect of Tulathromycin on Colonization Resistance, Antimicrobial Resistance, and Virulence of Human Gut Microbiota in Chemostats

    PubMed Central

    Hao, Haihong; Zhou, Shengxi; Cheng, Guyue; Dai, Menghong; Wang, Xu; Liu, Zhenli; Wang, Yulian; Yuan, Zonghui

    2016-01-01

    To evaluate microbiological safety of tulathromycin on human intestinal bacteria, tulathromycin (0, 0.1, 1, 10, and 100 μg/mL) was added into Chemostats. Before and after drug exposure, we monitored (1) population, SCFA products, antimicrobial resistance, and colonization resistance of gut microbiota, and (2) the antimicrobial resistance genes, transferability, virulent genes, pathogenicity of Enterococus faecalis. Results showed that low level of tulathromycin did not exhibit microbiological hazard on resistance selection and colonization resistance. However, high level of tulathromycin (10 and 100 μg/mL) may disturb colonization resistance of human gut microbiota and select antimicrobial resistant E. faecalis. Most of the selected resistant E. faecalis carried resistant gene of ermB, transferable element of Tn1545 and three virulence genes (esp, cylA, and ace). One of them (E. faecalis 143) was confirmed to have higher horizontal transfer risk and higher pathogenicity. The calculated no observable adverse effect concentration (NOAEC) and microbiological acceptable daily intake (mADI) in our study was 1 μg/mL and 14.66 μg/kg.bw/day, respectively. PMID:27092131

  1. 21 CFR 880.6885 - Liquid chemical sterilants/high level disinfectants.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Liquid chemical sterilants/high level... and Personal Use Miscellaneous Devices § 880.6885 Liquid chemical sterilants/high level disinfectants. (a) Identification. A liquid chemical sterilant/high level disinfectant is a germicide that...

  2. 21 CFR 880.6885 - Liquid chemical sterilants/high level disinfectants.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Liquid chemical sterilants/high level... and Personal Use Miscellaneous Devices § 880.6885 Liquid chemical sterilants/high level disinfectants. (a) Identification. A liquid chemical sterilant/high level disinfectant is a germicide that...

  3. 21 CFR 880.6885 - Liquid chemical sterilants/high level disinfectants.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Liquid chemical sterilants/high level... and Personal Use Miscellaneous Devices § 880.6885 Liquid chemical sterilants/high level disinfectants. (a) Identification. A liquid chemical sterilant/high level disinfectant is a germicide that...

  4. 21 CFR 880.6885 - Liquid chemical sterilants/high level disinfectants.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Liquid chemical sterilants/high level... and Personal Use Miscellaneous Devices § 880.6885 Liquid chemical sterilants/high level disinfectants. (a) Identification. A liquid chemical sterilant/high level disinfectant is a germicide that...

  5. 21 CFR 880.6885 - Liquid chemical sterilants/high level disinfectants.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Liquid chemical sterilants/high level... and Personal Use Miscellaneous Devices § 880.6885 Liquid chemical sterilants/high level disinfectants. (a) Identification. A liquid chemical sterilant/high level disinfectant is a germicide that...

  6. Development of integraded mechanistically-based degradation-mode models for performance assessment of high-level waste containers

    SciTech Connect

    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.

  7. Development of integrated mechanistically-based degradation-mode models for performance assessment of high-level waste containers

    SciTech Connect

    Bedrossian, P; Estill, J; Farmer, J; Hopper, R; Horn, J; Huang, J S; McCright, D; Roy, A; Wang, F; Wilfinger, K

    1999-02-08

    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-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 Gr 55, a carbon steel, or Monel 400. At the present time, Alloy C-22 and A516 G4 55 are favored.

  8. Electrochemical determination of the corrosion behavior of candidate alloys proposed for containment of high level nuclear waste in tuff

    SciTech Connect

    Glass, R.S.; Overturf, G.E.; Garrison, R.E.; McCright, R.D.

    1984-06-18

    Long-term geological disposal of nuclear waste requires corrosion-resistant canister materials for encapsulation. Several austenitic stainless steels are under consideration for such purposes for the disposal of high-level waste at the candidate repository site located at Yucca Mountain, Nevada. With regard to corrosion considerations, a worst case scenario at this prospective repository location would result from the intrusion of vadose water. This preliminary study focuses on the electrochemical and corrosion behavior of the candidate canister materials under worst-case repository environments. Electrochemical parameters related to localized attack (e.g., pitting potentials) and the electrochemical corrosion rates have been examined. 15 references, 15 figures, 4 tables.

  9. Sulfur incorporation in high level nuclear waste glass: A S K-edge XAFS investigation

    NASA Astrophysics Data System (ADS)

    Brendebach, B.; Denecke, M. A.; Roth, G.; Weisenburger, S.

    2009-11-01

    We perform X-ray absorption fine structure (XAFS) spectroscopy measurements at the sulfur K-edge to elucidate the electronic and geometric bonding of sulfur atoms in borosilicate glass used for the vitrification of high level radioactive liquid waste. The sulfur is incorporated as sulfate, most probably as sodium sulfate, which can be deduced from the X-ray absorption near edge structure (XANES) by fingerprint comparison with reference compounds. This finding is backed up by Raman spectroscopy investigation. In the extended XAFS data, no second shell beyond the first oxygen layer is visible. We argue that this is due to the sulfate being present as small clusters located into voids of the borosilicate network. Hence, destructive interference of the variable surrounding prohibits the presence of higher shell signals. The knowledge of the sulfur bonding characteristics is essential for further optimization of the glass composition and to balance the requirements of the process and glass quality parameters, viscosity and electrical resistivity on one side, waste loading and sulfur uptake on the other side.

  10. Modeling the corrosion of high-level waste containers: CAM-CRM interface

    SciTech Connect

    Bedrossian, P J; Farmer, J C; 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 repository 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 A5 16 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 Environment (NFE), as well as to the exacerbated conditions in the CAM-CRM crevice. [5]. Haynes International has published corrosion rates of Alloys 625 and C-22 in artificial crevice solutions (5-10 wt. % FeCl,) at various temperatures (25, 50 and 75 C) [6,7]. In this case, the observed rates for Alloy C-22 appear to be due to passive dissolution. It is believed that Alloy C-22 must be at an electrochemical potential above the repassivation potential to initiate localized corrosion.

  11. MODELING THE CORROSION OF HIGH-LEVEL WASTE CONTAINERS CAM-CRM INTERFACE

    SciTech Connect

    Farmer, Joseph; McCright, Daniel

    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-layer canister. In this particular design, the inner barrier is made of a corrosion resistant material (CRM) such as Alloy 625 or C-22, while the outer barrier is made of a corrosion-allowance material (CAM) such as carbon steel or Monel400. Initially, the containers will be hot and dry due to the heat generated by radioactive decay. However, the temperature will eventually drop to levels where both humid air and aqueous phase corrosion will be possible. As the outer barrier is penetrated, uniform corrosion of the CRM will be possible in exfoliated areas. The possibility for crevice formation between the CAM and CRM will also exist. In the case of either Alloy 625 or C-22, a crevice will have to form before significant penetration of the CRM can occur. Crevice corrosion of the CRMs has been well documented. Lillard and Scully have induced crevice corrosion in Alloy 625 during exposure to artificial sea water. Jones and Wilde have prepared simulated crevice solutions of FeCl{sub 2}, NiCl{sub 2} and CrCl{sub 3}, and measured substantial pH suppression. Asphahani measured the dissolution rates of Alloys 625 and C-22 in such artificial crevice solutions at various temperatures. Others have observed no significant localized attack in less severe environments.

  12. Modeling the corrosion of high-level waste containers CAM-CRM interface

    SciTech Connect

    Farmer, J.C.; McCright, M.

    1997-12-09

    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-layer canister. In this particular design,the inner barrier is made of a corrosion resistant material (CRM) such as Alloy 625 and C-22, while the outer barrier is made of a corrosion allowance material (CAM) such as carbon steel or Monel 400. Initially, the containers will be hot and dry due to the heat generated by radioactive decay. However, the temperature will eventually drop to levels where both humid air and aqueous phase corrosion will be possible. As the outer barrier is penetrated, uniform corrosion of the CRM will be possible of exfoliated areas. The possibility of crevice formation between the CAM and CRM will also exist. In the case of either Alloy 625 or C-22, a crevice will have to form before significant penetration of the CRM can occur. Crevice corrosion of the CRMs has been well documented.

  13. Constitutively vancomycin-resistant Enterococcus faecium resistant to synergistic beta-lactam combinations.

    PubMed Central

    Green, M; Binczewski, B; Pasculle, A W; Edmund, M; Barbadora, K; Kusne, S; Shlaes, D M

    1993-01-01

    Vancomycin resistance among enterococci has recently been recognized. Synergy between vancomycin and penicillin has been shown in vitro for isolates of Enterococcus faecium resistant to both of these antibiotics. We describe three isolates of vancomycin-resistant E. faecium which demonstrate unique phenotypic characteristics. The isolates exhibited high-level resistance to both vancomycin and teicoplanin, consistent with the VanA phenotype. However, resistance in these isolates could not be induced or cured, and mating experiments failed to detect a transfer of resistance. The combination of vancomycin and penicillin did not significantly change the MIC of penicillin for any of the three isolates. Immunoblotting with polyclonal anti-VanB antibody showed no reaction with the cellular proteins of these strains. Probing with a vanA oligonucleotide revealed hybridization with chromosomal but not plasmid DNA. The mechanism of constitutive resistance of those strains remains unclear. A second mutational change, perhaps involving PBP 5, may explain the presence of resistance to synergistic combination penicillin-vancomycin therapy. In vitro evaluation of penicillin-vancomycin should be carried out in all clinical cases where this therapeutic regimen is being considered. Images PMID:8328775

  14. Population genetic structure of a centipede species with high levels of developmental instability.

    PubMed

    Fusco, Giuseppe; Leśniewska, Małgorzata; Congiu, Leonardo; Bertorelle, Giorgio

    2015-01-01

    European populations of the geophilomorph centipede Haplophilus subterraneus show a high proportion of individuals with morphological anomalies, suggesting high levels of developmental instability. The broad geographic distribution of this phenomenon seems to exclude local environmental causes, but the source of instability is still to be identified. The goal of the present study was to collect quantitative data on the occurrence of phenodeviants in different populations, along with data on the patterns of genetic variation within and between populations, in order to investigate possible association between developmental instability and genetic features. In a sample of 11 populations of H. subterraneus, distributed in western and central Europe, we looked for phenodeviants, in particular with respect to trunk morphology, and studied genetic variation through the genotyping of microsatellite loci. Overall, no support was found to the idea that developmental instability in H. subterraneus is related to a specific patterns of genetic variation, including inbreeding estimates. We identified a major genetic partition that subdivides French populations from the others, and a low divergence among northwestern areas, which are possibly related to the post-glacial recolonization from southern refugia and/or to recent anthropogenic soil displacements. A weak correlation between individual number of leg bearing segments and the occurrence of trunk anomalies seems to support a trade-off between these two developmental traits. These results, complemented by preliminary data on developmental stability in two related species, suggest that the phenomenon has not a simple taxonomic distribution, while it exhibits an apparent localization in central and eastern Europe.

  15. Oxidative Alkaline leaching of Americium from simulated high-level nuclear waste sludges

    SciTech Connect

    Reed, Wendy A.; Garnov, Alexander Yu.; Rao, Linfeng; Nash, Kenneth L.; Bond, Andrew H.

    2004-01-23

    Oxidative alkaline leaching has been proposed to pre-treat the high-level nuclear waste sludges to remove some of the problematic (e.g., Cr) and/or non-radioactive (e.g., Na, Al) constituents before vitrification. It is critical to understand the behavior of actinides, americium and plutonium in particular, in oxidative alkaline leaching. We have studied the leaching behavior of americium from four different sludge simulants (BiPO{sub 4}, BiPO{sub 4 modified}, Redox, PUREX) using potassium permanganate and potassium persulfate in alkaline solutions. Up to 60% of americium sorbed onto the simulants is leached from the sludges by alkaline persulfate and permanganate. The percentage of americium leached increases with [NaOH] (between 1.0 and 5.0 M). The initial rate of americium leaching by potassium persulfate increases in the order BiPO{sub 4} sludge < Redox sludge < PUREX sludge. The data are most consistent with oxidation of Am{sup 3+} in the sludge to either AmO{sub 2}{sup +} or AmO{sub 2}{sup 2+} in solution. Though neither of these species is expected to exhibit long-term stability in solution, the potential for mobilization of americium from sludge samples would have to be accommodated in the design of any oxidative leaching process for real sludge samples.

  16. High-level production of functional muscle alpha-tropomyosin in Pichia pastoris.

    PubMed

    Hilario, E; Lataro, R C; Alegria, M C; Lavarda, S C; Ferro, J A; Bertolini, M C

    2001-06-22

    Although numerous studies have reported the production of skeletal muscle alpha-tropomyosin in E. coli, the protein needs to be modified at the amino terminus in order to be active. Without these modifications the protein does not bind to actin, does not exhibit head-to-tail polymerization, and does not inhibit the actomyosin Mg(2+)-ATPase in the absence of troponin. On the other hand, the protein produced in insect cells using baculovirus as an expression vector (Urbancikova, M., and Hitchcock-DeGregori, S. E., J. Biol. Chem., 269, 24310-24315, 1994) is only partially acetylated at its amino terminal and therefore is not totally functional. In an attempt to produce an unmodified functional recombinant muscle alpha-tropomyosin for structure-function correlation studies we have expressed the chicken skeletal alpha-tropomyosin cDNA in the yeast Pichia pastoris. Recombinant protein was produced at a high level (20 mg/L) and was similar to the wild type muscle protein in its ability to polymerize, to bind to actin and to regulate the actomyosin S1 Mg(2+)-ATPase.

  17. Nonlinear response of a clamped beam and plate to high levels of excitation

    NASA Astrophysics Data System (ADS)

    Wolfe, Howard F.; White, Robert G.

    Acoustic fatigue failure in aerospace structures has been a concern for many years. New prediction techniques are needed for the new materials and structural concepts of interest and higher sound pressure levels encountered for the hypersonic flight regime. The objective of this program of work is to improve the fundamental understanding of the nonlinear behavior of beams and plates excited from low to high levels of excitation. Experiments have been conducted utilizing a clamped-clamped (C-C) beam statically tested and shaker driven at increasing levels of excitation. Similarly, a C-C-C-C plate was acoustically excited in a progressive wave tube. The total strains and the components, bending and axial, were measured for increasing levels of excitation. The bending strain response modes induced exhibited a peak broadening and frequency increase with an increase in excitation levels. The bending strain amplitudes were slightly less than the total strains measured. While the axial strains increased with increasing excitation levels, they did not increase as rapidly as expected. The static test resulted in a linear relationship between the strain and the loads over the level of interest. The dynamic tests resulted in a nonlinear relationship between the response strains and the excitation levels.

  18. Ga(+) Basicity and Affinity Scales Based on High-Level Ab Initio Calculations.

    PubMed

    Brea, Oriana; Mó, Otilia; Yáñez, Manuel

    2015-10-26

    The structure, relative stability and bonding of complexes formed by the interaction between Ga(+) and a large set of compounds, including hydrocarbons, aromatic systems, and oxygen-, nitrogen-, fluorine and sulfur-containing Lewis bases have been investigated through the use of the high-level composite ab initio Gaussian-4 theory. This allowed us to establish rather accurate Ga(+) cation affinity (GaCA) and Ga(+) cation basicity (GaCB) scales. The bonding analysis of the complexes under scrutiny shows that, even though one of the main ingredients of the Ga(+) -base interaction is electrostatic, it exhibits a non-negligible covalent character triggered by the presence of the low-lying empty 4p orbital of Ga(+) , which favors a charge donation from occupied orbitals of the base to the metal ion. This partial covalent character, also observed in AlCA scales, is behind the dissimilarities observed when GaCA are compared with Li(+) cation affinities, where these covalent contributions are practically nonexistent. Quite unexpectedly, there are some dissimilarities between several Ga(+) -complexes and the corresponding Al(+) -analogues, mainly affecting the relative stability of π-complexes involving aromatic compounds.

  19. Exhibitions: Facing Outward, Pointing Inward

    ERIC Educational Resources Information Center

    McDonald, Joseph P.

    2007-01-01

    The Coalition of Essential Schools (CES) Exhibitions Project of the early 1990s produced a range of work that continues to inform the practice of using exhibitions as a "360 degree" method of transforming teaching and learning, community connections, school design, and assessment. Among that work was this paper coupling the origins of exhibitions…

  20. Does high serum uric acid level cause aspirin resistance?

    PubMed

    Yildiz, Bekir S; Ozkan, Emel; Esin, Fatma; Alihanoglu, Yusuf I; Ozkan, Hayrettin; Bilgin, Murat; Kilic, Ismail D; Ergin, Ahmet; Kaftan, Havane A; Evrengul, Harun

    2016-06-01

    In patients with coronary artery disease (CAD), though aspirin inhibits platelet activation and reduces atherothrombotic complications, it does not always sufficiently inhibit platelet function, thereby causing a clinical situation known as aspirin resistance. As hyperuricemia activates platelet turnover, aspirin resistance may be specifically induced by increased serum uric acid (SUA) levels. In this study, we thus investigated the association between SUA level and aspirin resistance in patients with CAD. We analyzed 245 consecutive patients with stable angina pectoris (SAP) who in coronary angiography showed more than 50% occlusion in a major coronary artery. According to aspirin resistance, two groups were formed: the aspirin resistance group (Group 1) and the aspirin-sensitive group (Group 2). Compared with those of Group 2, patients with aspirin resistance exhibited significantly higher white blood cell counts, neutrophil counts, neutrophil-to-lymphocyte ratios, SUA levels, high-sensitivity C-reactive protein levels, and fasting blood glucose levels. After multivariate analysis, a high level of SUA emerged as an independent predictor of aspirin resistance. The receiver-operating characteristic analysis provided a cutoff value of 6.45 mg/dl for SUA to predict aspirin resistance with 79% sensitivity and 65% specificity. Hyperuricemia may cause aspirin resistance in patients with CAD and high SUA levels may indicate aspirin-resistant patients. Such levels should thus recommend avoiding heart attack and stroke by adjusting aspirin dosage. PMID:26656902

  1. Copper-resistant enteric bacteria from United Kingdom and Australian piggeries.

    PubMed Central

    Williams, J R; Morgan, A G; Rouch, D A; Brown, N L; Lee, B T

    1993-01-01

    Thirty-three enteric isolates from Australian (Escherichia coli only) and United Kingdom (U.K.) (Salmonella sp., Citrobacter spp., and E. coli) piggeries were characterized with respect to their copper resistance. The copper resistance phenotypes of four new Australian E. coli isolates were comparable with that of the previously studied E. coli K-12 strain ED8739(pRJ1004), in that the resistance level in rich media was high (up to 18 mM CuSO4) and resistance was inducible. Copper resistance was transferable by conjugation from the new Australian isolates to E. coli K-12 recipients. DNA similarity between the new Australian isolates and the pco copper resistance determinant located on plasmid pRJ1004 was strong as measured by DNA-DNA hybridization; however, the copper resistance plasmids were nonidentical as indicated by the presence of restriction fragment length polymorphisms between the plasmids. DNA-DNA hybridization and polymerase chain reaction analysis demonstrated DNA homology between the pco determinant and DNA from the U.K.E. coli, Salmonella sp., and Citrobacter freundii isolates. However, the copper resistance level and inducibility were variable among the U.K. strains. Of the U.K. E. coli isolates, 1 demonstrated a high level of copper resistance, 4 exhibited intermediate resistance, and 16 showed a low level of copper resistance; all of these resistances were expressed constitutively. A single U.K. C. freundii isolate, had a high level of copper resistance, inducible by subtoxic levels of copper. Transconjugants from one E. coli and one C. freundii donor, with E. coli K-12 strain UB1637 as a recipient, showed copper resistance levels and inducibility of resistance which differed from that expressed from plasmid pRJ1004.(ABSTRACT TRUNCATED AT 250 WORDS) Images PMID:8368840

  2. Against the Odds Exhibition Opens

    MedlinePlus

    ... LA and Vox Populi organizations. Photo courtesy of Bill Branson At the exhibition, HIV and AIDS were topics addressed by Dr. Victoria Cargill (right), Director of Clinical Studies and Director of Minority ...

  3. Greenhouse Earth: A Traveling Exhibition

    SciTech Connect

    Booth, W.H.; Caesar, S.

    1992-09-01

    The Franklin Institute Science Museum provided an exhibit entitled the Greenhouse Earth: A Traveling Exhibition. This 3500 square-foot exhibit on global climate change was developed in collaboration with the Association of Science-Technology Centers. The exhibit opened at The Franklin Institute on February 14, 1992, welcoming 291,000 visitors over its three-month stay. During its three-year tour, Greenhouse Earth will travel to ten US cities, reaching two million visitors. Greenhouse Earth aims to deepen public understanding of the scientific issues of global warming and the conservation measures that can be taken to slow its effects. The exhibit features hands-on exhibitry, interactive computer programs and videos, a theater production, a demonstration cart,'' guided tours, and lectures. supplemental educational programs at the Institute included a teachers preview, a symposium on climate change, and a satellite field trip.'' The development of Greenhouse Earth included front-end and formative evaluation procedures. Evaluation includes interviews with visitors, prototypes, and summative surveys for participating museums. During its stay in Philadelphia, Greenhouse Earth was covered by the local and national press, with reviews in print and broadcast media. Greenhouse Earth is the first large-scale museum exhibit to address global climate change.

  4. Honey bees (Apis mellifera) reared in brood combs containing high levels of pesticide residues exhibit increased susceptibility to Nosema (Microsporidia) infection.

    PubMed

    Wu, Judy Y; Smart, Matthew D; Anelli, Carol M; Sheppard, Walter S

    2012-03-01

    Nosema ceranae and pesticide exposure can contribute to honey bee health decline. Bees reared from brood comb containing high or low levels of pesticide residues were placed in two common colony environments. One colony was inoculated weekly with N. ceranae spores in sugar syrup and the other colony received sugar syrup only. Worker honey bees were sampled weekly from the treatment and control colonies and analyzed for Nosema spore levels. Regardless of the colony environment (spores+syrup added or syrup only added), a higher proportion of bees reared from the high pesticide residue brood comb became infected with N. ceranae, and at a younger age, compared to those reared in low residue brood combs. These data suggest that developmental exposure to pesticides in brood comb increases the susceptibility of bees to N. ceranae infection.

  5. Exploiting selective genotyping to study genetic diversity of resistance to Fusarium head blight in barley.

    PubMed

    Wingbermuehle, W J; Gustus, C; Smith, K P

    2004-10-01

    Numerous barley cultivars from around the world have been identified as potential sources of Fusarium head blight (FHB) resistance genes. All of these cultivars exhibit partial resistance, and several mapping studies have shown that resistance to FHB is controlled by multiple genes. Successful development of barley cultivars with high levels of FHB resistance will require combining genes from multiple sources. We characterized five potential new sources of FHB resistance ('AC Oxbow', 'Atahualpa', 'HOR211', 'PFC88209', and 'Zhedar#1') to determine if they contain new FHB resistance genes. Cluster analysis, using a set of 80 SSR markers distributed throughout the genome, showed that most of the new sources of resistance were not similar to three cultivars that have been used in previous FHB mapping studies ('Chevron', 'Frederickson', and 'Gobernadora'), with 'Atahualpa' and 'HOR211' being the most dissimilar. By selective genotyping, we determined whether markers linked to six known FHB resistance quantitative trait loci (QTLs), discovered in other genotypes, explained variation for resistance in advanced breeding populations created from the new sources of resistance. Markers linked to four of the six known QTLs were associated with FHB severity in at least one of the populations. However, none of the six QTL regions were associated with variation for FHB severity in populations derived from crosses that utilized sources of resistance HOR211 or PFC88209. Selective genotyping is an efficient method for breeders to utilize current QTL information about disease resistance to search for new resistance genes. PMID:15257434

  6. Hi-LAB: A New Measure of Aptitude for High-Level Language Proficiency

    ERIC Educational Resources Information Center

    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,…

  7. Alternatives Generation and Analysis for Heat Removal from High Level Waste Tanks

    SciTech Connect

    WILLIS, W.L.

    2000-06-15

    This document addresses the preferred combination of design and operational configurations to provide heat removal from high-level waste tanks during Phase 1 waste feed delivery to prevent the waste temperature from exceeding tank safety requirement limits. An interim decision for the preferred method to remove the heat from the high-level waste tanks during waste feed delivery operations is presented herein.

  8. Characteristics Data Base: Programmer's guide to the High-Level Waste Data Base

    SciTech Connect

    Jones, K.E. ); Salmon, R. )

    1990-08-01

    The High-Level Waste Data Base is a menu-driven PC data base developed as part of OCRWM's technical data base on the characteristics of potential repository wastes, which also includes spent fuel and other materials. This programmer's guide completes the documentation for the High-Level Waste Data Base, the user's guide having been published previously. 3 figs.

  9. 40 CFR 1065.725 - High-level ethanol-gasoline blends.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ethanol used for blending must be either denatured ethanol meeting the specifications in 40 CFR 80.1610... 40 Protection of Environment 33 2014-07-01 2014-07-01 false High-level ethanol-gasoline blends... Calibration Standards § 1065.725 High-level ethanol-gasoline blends. For testing vehicles capable of...

  10. 78 FR 70281 - United States-Mexico High Level Economic Dialogue

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-25

    ... United States-Mexico High Level Economic Dialogue AGENCY: International Trade Administration, Commerce... Register notice on the United States-Mexico High Level Economic Dialogue. DATES: The agency must receive... largest export market and third largest overall trading partner. The United States, in turn, is...

  11. F14512, a polyamine-vectorized inhibitor of topoisomerase II, exhibits a marked anti-tumor activity in ovarian cancer.

    PubMed

    Thibault, Benoît; Clement, Emily; Zorza, Grégoire; Meignan, Samuel; Delord, Jean-Pierre; Couderc, Bettina; Bailly, Christian; Narducci, Fabrice; Vandenberghe, Isabelle; Kruczynski, Anna; Guilbaud, Nicolas; Ferré, Pierre; Annereau, Jean-Philippe

    2016-01-01

    Epithelial ovarian cancer is the fourth cause of death among cancer-bearing women and frequently associated with carboplatin resistance, underlining the need for more efficient and targeted therapies. F14512 is an epipodophylotoxin-core linked to a spermine chain which enters cells via the polyamine transport system (PTS). Here, we investigate this novel concept of vectorization in ovarian cancer. We compared the effects of etoposide and F14512 on a panel of five carboplatin-sensitive or resistant ovarian cancer models. We assessed the incorporation of F17073, a spermine-linked fluorescent probe, in these cells and in 18 clinical samples. We then showed that F14512 exhibits a high anti-proliferative and pro-apoptotic activity, particularly in cells with high levels of F17073 incorporation. Consistently, F14512 significantly inhibited tumor growth compared to etoposide, in a cisplatin-resistant A2780R subcutaneous model, at a dose of 1.25 mg/kg. In addition, ex vivo analysis indicated that 15 out of 18 patients presented a higher F17073 incorporation into tumor cells compared to normal cells. Overall, our data suggest that F14512, a targeted drug with a potent anti-tumor efficacy, constitutes a potential new therapy for highly PTS-positive and platinum-resistant ovarian cancer-bearing patients.

  12. Perspectives on the closed fuel cycle Implications for high-level waste matrices

    NASA Astrophysics Data System (ADS)

    Gras, Jean-Marie; Quang, Richard Do; Masson, Hervé; Lieven, Thierry; Ferry, Cécile; Poinssot, Christophe; Debes, Michel; Delbecq, Jean-Michel

    2007-05-01

    Nuclear energy accounts for 80% of electricity production in France, generating approximately 1150 t of spent fuel for an electrical output of 420 TWh. Based on a reprocessing-conditioning-recycling strategy, the orientations taken by Électricité de France (EDF) for the mid-term and the far-future are to keep the fleet performances at the highest level, and to maintain the nuclear option fully open by the replacement of present pressurized water reactor (PWR) by new light water reactor (LWR), such as the evolutionary pressurized reactor (EPR) and future Generation IV designs. Adaptations of waste materials to new requirements will come with these orientations in order to meet long-term energy sustainability. In particular, waste materials and spent fuels are expected to meet increased requirements in comparison with the present situation. So the treatment of higher burn-up UO2 spent fuel and MOX fuel requires determining the performances of glass and other matrices according to several criteria: chemical 'digestibility' (i.e. capacity of glass to incorporate fission products and minor actinides without loss of quality), resistance to alpha self-irradiation, residual power in view of disposal. Considering the long-term evolution of spent MOX fuel in storage, the helium production, the influence of irradiation damages accumulation and the evolution of the microstructure of the fuel pellet need to be known, as well as for the future fuels. Further, the eventual transmutation of minor actinides in fast neutron reactors (FR) of Generation IV, if its interest in optimising high-level waste management is proven, may also raise new challenges about the materials and fuel design. Some major questions in terms of waste materials and spent fuel are discussed in this paper.

  13. Design and performance of atomizing nozzles for spray calcination of high-level wastes

    SciTech Connect

    Miller, F.A.; Stout, L.A.

    1981-05-01

    A key aspect of high-level liquid-waste spray calcination is waste-feed atomization by using air atomizing nozzles. Atomization substantially increases the heat transfer area of the waste solution, which enhances rapid drying. Experience from the spray-calciner operations has demonstrated that nozzle flow conditions that produce 70-..mu.. median-volume-diameter or smaller spray droplets are required for small-scale spray calciners (drying capacity less than 80 L/h). For large-scale calciners (drying capacity greater than 300 L/h), nozzle flow conditions that produce 100-..mu.. median-volume-diameter or smaller spray droplets are required. Mass flow ratios of 0.2 to 0.4, depending on nozzle size, are required for proper operation of internal-mix atomizing nozzles. Both internal-mix and external-mix nozzles have been tested at PNL. Due to the lower airflow requirements and fewer large droplets produced, the internal-mix nozzle has been chosen for primary development in the spray calciner program at PNL. Several nozzle air-cap materials for internal-mix nozzles have been tested for wear resistance. Results show that nozzle air caps of stainless steel and Cer-vit (a machineable glass ceramic) are suceptible to rapid wear by abrasive slurries, whereas air caps of alumina and reaction-bonded silicon nitride show only slow wear. Longer-term testing is necessary to determine more accurately the actual frequency of nozzle replacement. Atomizing nozzle air caps of alumina are subject to fracture from thermal shock, whereas air caps of silicon nitride and Cer-vit are not. Fractured nozzles are held in place by the air-cap retaining ring and continue to atomize satisfactorily. Therefore, fractures caused by thermal shocking do not necessarily result in nozzle failure.

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

    SciTech Connect

    Farmer, J.C.; Van Konynenburg, R.A.; McCright, R.D. ); Gdowski, G.E. )

    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.

  15. Precautionary practices of healthcare workers who disinfect medical and dental devices using high-level disinfectants.

    PubMed

    Henn, Scott A; Boiano, James M; Steege, Andrea L

    2015-02-01

    BACKGROUND High-level disinfectants (HLDs) are used throughout the healthcare industry to chemically disinfect reusable, semicritical medical and dental devices to control and prevent healthcare-associated infections among patient populations. Workers who use HLDs are at risk of exposure to these chemicals, some of which are respiratory and skin irritants and sensitizers. OBJECTIVE To evaluate exposure controls used and to better understand impediments to healthcare workers using personal protective equipment while handling HLDs. DESIGN Web-based survey. PARTICIPANTS A targeted sample of members of professional practice organizations representing nurses, technologists/technicians, dental professionals, respiratory therapists, and others who reported handling HLDs in the previous 7 calendar days. Participating organizations invited either all or a random sample of members via email, which included a hyperlink to the survey. METHODS Descriptive analyses were conducted including simple frequencies and prevalences. RESULTS A total of 4,657 respondents completed the survey. The HLDs used most often were glutaraldehyde (59%), peracetic acid (16%), and ortho-phthalaldehyde (15%). Examples of work practices or events that could increase exposure risk included failure to wear water-resistant gowns (44%); absence of standard procedures for minimizing exposure (19%); lack of safe handling training (17%); failure to wear protective gloves (9%); and a spill/leak of HLD during handling (5%). Among all respondents, 12% reported skin contact with HLDs, and 33% of these respondents reported that they did not always wear gloves. CONCLUSION Findings indicated that precautionary practices were not always used, underscoring the importance of improved employer and worker training and education regarding HLD hazards.

  16. Geomicrobiology of High Level Nuclear Waste-Contaminated Vadose Sediments at the Hanford Site, Washington State

    SciTech Connect

    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.

  17. Precautionary practices of healthcare workers who disinfect medical and dental devices using high-level disinfectants.

    PubMed

    Henn, Scott A; Boiano, James M; Steege, Andrea L

    2015-02-01

    BACKGROUND High-level disinfectants (HLDs) are used throughout the healthcare industry to chemically disinfect reusable, semicritical medical and dental devices to control and prevent healthcare-associated infections among patient populations. Workers who use HLDs are at risk of exposure to these chemicals, some of which are respiratory and skin irritants and sensitizers. OBJECTIVE To evaluate exposure controls used and to better understand impediments to healthcare workers using personal protective equipment while handling HLDs. DESIGN Web-based survey. PARTICIPANTS A targeted sample of members of professional practice organizations representing nurses, technologists/technicians, dental professionals, respiratory therapists, and others who reported handling HLDs in the previous 7 calendar days. Participating organizations invited either all or a random sample of members via email, which included a hyperlink to the survey. METHODS Descriptive analyses were conducted including simple frequencies and prevalences. RESULTS A total of 4,657 respondents completed the survey. The HLDs used most often were glutaraldehyde (59%), peracetic acid (16%), and ortho-phthalaldehyde (15%). Examples of work practices or events that could increase exposure risk included failure to wear water-resistant gowns (44%); absence of standard procedures for minimizing exposure (19%); lack of safe handling training (17%); failure to wear protective gloves (9%); and a spill/leak of HLD during handling (5%). Among all respondents, 12% reported skin contact with HLDs, and 33% of these respondents reported that they did not always wear gloves. CONCLUSION Findings indicated that precautionary practices were not always used, underscoring the importance of improved employer and worker training and education regarding HLD hazards. PMID:25633000

  18. High level seismic/vibrational tests at the HDR: An overview

    SciTech Connect

    Kot, C.A.; Srinivasan, M.G.; Hsieh, B.J.; Schrammel, D.; Malcher, L.; Steinhilber, H.; Costello, J.F.

    1991-12-31

    As part of the Phase II testing at the HDR Test Facility in Kahl/Main, FRG, two series of high-level seismic/vibrational experiments were performed. In the first of these (SHAG) a coast-down shaker, mounted on the reactor operating floor and capable of generating 1000 tonnes of force, was used to investigate full-scale structural response, soil-structure interaction (SSI), and piping/equipment response at load levels equivalent to those of a design basis earthquake. The HDR soil/structure system was tested to incipient failure exhibiting highly nonlinear response. In the load transmission from structure to piping/equipment significant response amplifications and shifts to higher frequencies occurred. The performance of various pipe support configurations was evaluated. This latter effort was continued in the second series of tests (SHAM), in which an in-plant piping system was investigated at simulated seismic loads (generated by two servo-hydraulic actuators each capable of generating 40 tonnes of force), that exceeded design levels manifold and resulted in considerable pipe plastification and failure of some supports (snubbers). The evaluation of six different support configurations demonstrated that proper system design (for a given spectrum) rather than number of supports or system stiffness is essential to limiting pipe stresses. Pipe strains at loads exceeding the design level eightfold were still tolerable, indicating that pipe failure even under extreme seismic loads is unlikely inspite of multiple support failures. Conservatively, an excess capacity (margin) of at least four was estimated for the piping system, and the pipe damping was found to be 4%. Comparisons of linear and nonlinear computational results with measurements showed that analytical predictions have wide scatter and do not necessarily yield conservative responses, underpredicting, in particular, peak support forces.

  19. High level seismic/vibrational tests at the HDR: An overview

    SciTech Connect

    Kot, C.A.; Srinivasan, M.G.; Hsieh, B.J. ); Schrammel, D.; Malcher, L. ); Steinhilber, H. ); Costello, J.F. . Office of Nuclear Regulatory Research)

    1991-01-01

    As part of the Phase II testing at the HDR Test Facility in Kahl/Main, FRG, two series of high-level seismic/vibrational experiments were performed. In the first of these (SHAG) a coast-down shaker, mounted on the reactor operating floor and capable of generating 1000 tonnes of force, was used to investigate full-scale structural response, soil-structure interaction (SSI), and piping/equipment response at load levels equivalent to those of a design basis earthquake. The HDR soil/structure system was tested to incipient failure exhibiting highly nonlinear response. In the load transmission from structure to piping/equipment significant response amplifications and shifts to higher frequencies occurred. The performance of various pipe support configurations was evaluated. This latter effort was continued in the second series of tests (SHAM), in which an in-plant piping system was investigated at simulated seismic loads (generated by two servo-hydraulic actuators each capable of generating 40 tonnes of force), that exceeded design levels manifold and resulted in considerable pipe plastification and failure of some supports (snubbers). The evaluation of six different support configurations demonstrated that proper system design (for a given spectrum) rather than number of supports or system stiffness is essential to limiting pipe stresses. Pipe strains at loads exceeding the design level eightfold were still tolerable, indicating that pipe failure even under extreme seismic loads is unlikely inspite of multiple support failures. Conservatively, an excess capacity (margin) of at least four was estimated for the piping system, and the pipe damping was found to be 4%. Comparisons of linear and nonlinear computational results with measurements showed that analytical predictions have wide scatter and do not necessarily yield conservative responses, underpredicting, in particular, peak support forces.

  20. Production of Cloned Miniature Pigs Expressing High Levels of Human Apolipoprotein(a) in Plasma.

    PubMed

    Ozawa, Masayuki; Himaki, Takehiro; Ookutsu, Shoji; Mizobe, Yamato; Ogawa, Junki; Miyoshi, Kazuchika; Yabuki, Akira; Fan, Jianglin; Yoshida, Mitsutoshi

    2015-01-01

    High lipoprotein(a) [Lp(a)] levels are a major risk factor for the development of atherosclerosis. However, because apolipoprotein(a) [apo(a)], the unique component of Lp(a), is found only in primates and humans, the study of human Lp(a) has been hampered due to the lack of appropriate animal models. Using somatic cell nuclear transfer (SCNT) techniques, we produced transgenic miniature pigs expressing human apo(a) in the plasma. First, we placed the hemagglutinin (HA)-tagged cDNA of human apo(a) under the control of the β-actin promoter and cytomegalovirus enhancer, and then introduced this construct into kidney epithelial cells. Immunostaining of cells with anti-HA antibody allowed identification of cells stably expressing apo(a); one of the positive clones was used to provide donor cells for SCNT, yielding blastocysts that expressed apo(a). Immunohistochemical analysis of tissue sections and RT-PCR analysis of total RNA from organs of cloned piglet revealed that apo(a) is expressed in various tissues/organs including heart, liver, kidney, and intestine. More importantly, a transgenic line exhibited a high level (>400 mg/dL) of Lp(a) in plasma, and the transgenic apo(a) gene was transmitted to the offspring. Thus, we generated a human apo(a)-transgenic miniature pig that can be used as a model system to study advanced atherosclerosis related to human disease. The anatomical and physiological similarities between the swine and human cardiovascular systems will make this pig model a valuable source of information on the role of apo(a) in the formation of atherosclerosis, as well as the mechanisms underlying vascular health and disease. PMID:26147378

  1. Low-temperature lithium diffusion in simulated high-level boroaluminosilicate nuclear waste glasses

    SciTech Connect

    Neeway, James J.; Kerisit, Sebastien N.; Gin, Stephane; Wang, Zhaoying; Zhu, Zihua; Ryan, Joseph V.

    2014-12-01

    Ion exchange is recognized as an integral, if underrepresented, mechanism influencing glass corrosion. However, due to the formation of various alteration layers in the presence of water, it is difficult to conclusively deconvolute the mechanisms of ion exchange from other processes occurring simultaneously during corrosion. In this work, an operationally inert non-aqueous solution was used as an alkali source material to isolate ion exchange and study the solid-state diffusion of lithium. Specifically, the experiments involved contacting glass coupons relevant to the immobilization of high-level nuclear waste, SON68 and CJ-6, which contained Li in natural isotope abundance, with a non-aqueous solution of 6LiCl dissolved in dimethyl sulfoxide at 90 °C for various time periods. The depth profiles of major elements in the glass coupons were measured using time-of-flight secondary ion mass spectrometry (ToF-SIMS). Lithium interdiffusion coefficients, DLi, were then calculated based on the measured depth profiles. The results indicate that the penetration of 6Li is rapid in both glasses with the simplified CJ-6 glass (D6Li ≈ 4.0-8.0 × 10-21 m2/s) exhibiting faster exchange than the more complex SON68 glass (DLi ≈ 2.0-4.0 × 10-21 m2/s). Additionally, sodium ions present in the glass were observed to participate in ion exchange reactions; however, different diffusion coefficients were necessary to fit the diffusion profiles of the two alkali ions. Implications of the diffusion coefficients obtained in the absence of alteration layers to the long-term performance of nuclear waste glasses in a geological repository system are also discussed.

  2. Population genetic structure of a centipede species with high levels of developmental instability.

    PubMed

    Fusco, Giuseppe; Leśniewska, Małgorzata; Congiu, Leonardo; Bertorelle, Giorgio

    2015-01-01

    European populations of the geophilomorph centipede Haplophilus subterraneus show a high proportion of individuals with morphological anomalies, suggesting high levels of developmental instability. The broad geographic distribution of this phenomenon seems to exclude local environmental causes, but the source of instability is still to be identified. The goal of the present study was to collect quantitative data on the occurrence of phenodeviants in different populations, along with data on the patterns of genetic variation within and between populations, in order to investigate possible association between developmental instability and genetic features. In a sample of 11 populations of H. subterraneus, distributed in western and central Europe, we looked for phenodeviants, in particular with respect to trunk morphology, and studied genetic variation through the genotyping of microsatellite loci. Overall, no support was found to the idea that developmental instability in H. subterraneus is related to a specific patterns of genetic variation, including inbreeding estimates. We identified a major genetic partition that subdivides French populations from the others, and a low divergence among northwestern areas, which are possibly related to the post-glacial recolonization from southern refugia and/or to recent anthropogenic soil displacements. A weak correlation between individual number of leg bearing segments and the occurrence of trunk anomalies seems to support a trade-off between these two developmental traits. These results, complemented by preliminary data on developmental stability in two related species, suggest that the phenomenon has not a simple taxonomic distribution, while it exhibits an apparent localization in central and eastern Europe. PMID:26029915

  3. Production of Cloned Miniature Pigs Expressing High Levels of Human Apolipoprotein(a) in Plasma

    PubMed Central

    Ozawa, Masayuki; Himaki, Takehiro; Ookutsu, Shoji; Mizobe, Yamato; Ogawa, Junki; Miyoshi, Kazuchika; Yabuki, Akira; Fan, Jianglin; Yoshida, Mitsutoshi

    2015-01-01

    High lipoprotein(a) [Lp(a)] levels are a major risk factor for the development of atherosclerosis. However, because apolipoprotein(a) [apo(a)], the unique component of Lp(a), is found only in primates and humans, the study of human Lp(a) has been hampered due to the lack of appropriate animal models. Using somatic cell nuclear transfer (SCNT) techniques, we produced transgenic miniature pigs expressing human apo(a) in the plasma. First, we placed the hemagglutinin (HA)-tagged cDNA of human apo(a) under the control of the β-actin promoter and cytomegalovirus enhancer, and then introduced this construct into kidney epithelial cells. Immunostaining of cells with anti-HA antibody allowed identification of cells stably expressing apo(a); one of the positive clones was used to provide donor cells for SCNT, yielding blastocysts that expressed apo(a). Immunohistochemical analysis of tissue sections and RT-PCR analysis of total RNA from organs of cloned piglet revealed that apo(a) is expressed in various tissues/organs including heart, liver, kidney, and intestine. More importantly, a transgenic line exhibited a high level (>400 mg/dL) of Lp(a) in plasma, and the transgenic apo(a) gene was transmitted to the offspring. Thus, we generated a human apo(a)–transgenic miniature pig that can be used as a model system to study advanced atherosclerosis related to human disease. The anatomical and physiological similarities between the swine and human cardiovascular systems will make this pig model a valuable source of information on the role of apo(a) in the formation of atherosclerosis, as well as the mechanisms underlying vascular health and disease. PMID:26147378

  4. Population Genetic Structure of a Centipede Species with High Levels of Developmental Instability

    PubMed Central

    Fusco, Giuseppe; Leśniewska, Małgorzata; Congiu, Leonardo; Bertorelle, Giorgio

    2015-01-01

    European populations of the geophilomorph centipede Haplophilus subterraneus show a high proportion of individuals with morphological anomalies, suggesting high levels of developmental instability. The broad geographic distribution of this phenomenon seems to exclude local environmental causes, but the source of instability is still to be identified. The goal of the present study was to collect quantitative data on the occurrence of phenodeviants in different populations, along with data on the patterns of genetic variation within and between populations, in order to investigate possible association between developmental instability and genetic features. In a sample of 11 populations of H. subterraneus, distributed in western and central Europe, we looked for phenodeviants, in particular with respect to trunk morphology, and studied genetic variation through the genotyping of microsatellite loci. Overall, no support was found to the idea that developmental instability in H. subterraneus is related to a specific patterns of genetic variation, including inbreeding estimates. We identified a major genetic partition that subdivides French populations from the others, and a low divergence among northwestern areas, which are possibly related to the post-glacial recolonization from southern refugia and/or to recent anthropogenic soil displacements. A weak correlation between individual number of leg bearing segments and the occurrence of trunk anomalies seems to support a trade-off between these two developmental traits. These results, complemented by preliminary data on developmental stability in two related species, suggest that the phenomenon has not a simple taxonomic distribution, while it exhibits an apparent localization in central and eastern Europe. PMID:26029915

  5. Incorporation of Bacterial Blight Resistance Genes Into Lowland Rice Cultivar Through Marker-Assisted Backcross Breeding.

    PubMed

    Pradhan, Sharat Kumar; Nayak, Deepak Kumar; Pandit, Elssa; Behera, Lambodar; Anandan, Annamalai; Mukherjee, Arup Kumar; Lenka, Srikanta; Barik, Durga Prasad

    2016-07-01

    Bacterial blight (BB) of rice caused by Xanthomonas oryzae pv. oryzae is a major disease of rice in many rice growing countries. Pyramided lines carrying two BB resistance gene combinations (Xa21+xa13 and Xa21+xa5) were developed in a lowland cultivar Jalmagna background through backcross breeding by integrating molecular markers. In each backcross generation, markers closely linked to the disease resistance genes were used to select plants possessing the target genes. Background selection was continued in those plants carrying resistant genes until BC(3) generation. Plants having the maximum contribution from the recurrent parent genome were selected in each generation and hybridized with the recipient parent. The BB-pyramided line having the maximum recipient parent genome recovery of 95% was selected among BC3F1 plants and selfed to isolate homozygous BC(3)F(2) plants with different combinations of BB resistance genes. Twenty pyramided lines with two resistance gene combinations exhibited high levels of tolerance against the BB pathogen. In order to confirm the resistance, the pyramided lines were inoculated with different X. oryzae pv. oryzae strains of Odisha for bioassay. The genotypes with combination of two BB resistance genes conferred high levels of resistance to the predominant X. oryzae pv. oryzae isolates prevalent in the region. The pyramided lines showed similarity with the recipient parent with respect to major agro-morphologic traits.

  6. Mitochondrial DNA exhibits resistance to induced point and deletion mutations

    PubMed Central

    Valente, William J.; Ericson, Nolan G.; Long, Alexandra S.; White, Paul A.; Marchetti, Francesco; Bielas, Jason H.

    2016-01-01

    The accumulation of somatic mitochondrial DNA (mtDNA) mutations contributes to the pathogenesis of human disease. Currently, mitochondrial mutations are largely considered results of inaccurate processing of its heavily damaged genome. However, mainly from a lack of methods to monitor mtDNA mutations with sufficient sensitivity and accuracy, a link between mtDNA damage and mutation has not been established. To test the hypothesis that mtDNA-damaging agents induce mtDNA mutations, we exposed MutaTMMouse mice to benzo[a]pyrene (B[a]P) or N-ethyl-N-nitrosourea (ENU), daily for 28 consecutive days, and quantified mtDNA point and deletion mutations in bone marrow and liver using our newly developed Digital Random Mutation Capture (dRMC) and Digital Deletion Detection (3D) assays. Surprisingly, our results demonstrate mutagen treatment did not increase mitochondrial point or deletion mutation frequencies, despite evidence both compounds increase nuclear DNA mutations and demonstrated B[a]P adduct formation in mtDNA. These findings contradict models of mtDNA mutagenesis that assert the elevated rate of mtDNA mutation stems from damage sensitivity and abridged repair capacity. Rather, our results demonstrate induced mtDNA damage does not readily convert into mutation. These findings suggest robust mitochondrial damage responses repress induced mutations after mutagen exposure. PMID:27550180

  7. Why Low Bounce Balls Exhibit High Rolling Resistance

    ERIC Educational Resources Information Center

    Cross, Rod

    2015-01-01

    A simple experiment is described to measure the coefficient of rolling friction for a low bounce ball rolling on a horizontal surface. As observed previously by others, the coefficient increased with rolling speed. The energy loss due to rolling friction can be explained in terms of the measured coefficient of restitution for the ball, meaning…

  8. Considering High-Tech Exhibits?

    ERIC Educational Resources Information Center

    Routman, Emily

    1994-01-01

    Discusses a variety of high-tech exhibit media used in The Living World, an educational facility operated by The Saint Louis Zoo. Considers the strengths and weaknesses of holograms, video, animatronics, video-equipped microscopes, and computer interactives. Computer interactives are treated with special attention. (LZ)

  9. Mechanisms of drug resistance: quinolone resistance

    PubMed Central

    Hooper, David C.; Jacoby, George A.

    2015-01-01

    Quinolone antimicrobials are synthetic and widely used in clinical medicine. Resistance emerged with clinical use and became common in some bacterial pathogens. Mechanisms of resistance include two categories of mutation and acquisition of resistance-conferring genes. Resistance mutations in one or both of the two drug target enzymes, DNA gyrase and DNA topoisomerase IV, are commonly in a localized domain of the GyrA and ParE subunits of the respective enzymes and reduce drug binding to the enzyme-DNA complex. Other resistance mutations occur in regulatory genes that control the expression of native efflux pumps localized in the bacterial membrane(s). These pumps have broad substrate profiles that include quinolones as well as other antimicrobials, disinfectants, and dyes. Mutations of both types can accumulate with selection pressure and produce highly resistant strains. Resistance genes acquired on plasmids can confer low-level resistance that promotes the selection of mutational high-level resistance. Plasmid-encoded resistance is due to Qnr proteins that protect the target enzymes from quinolone action, one mutant aminoglycoside-modifying enzyme that also modifies certain quinolones, and mobile efflux pumps. Plasmids with these mechanisms often encode additional antimicrobial resistances and can transfer multidrug resistance that includes quinolones. Thus, the bacterial quinolone resistance armamentarium is large. PMID:26190223

  10. Ontological Problem-Solving Framework for Assigning Sensor Systems and Algorithms to High-Level Missions

    PubMed Central

    Qualls, Joseph; Russomanno, David J.

    2011-01-01

    The lack of knowledge models to represent sensor systems, algorithms, and missions makes opportunistically discovering a synthesis of systems and algorithms that can satisfy high-level mission specifications impractical. A novel ontological problem-solving framework has been designed that leverages knowledge models describing sensors, algorithms, and high-level missions to facilitate automated inference of assigning systems to subtasks that may satisfy a given mission specification. To demonstrate the efficacy of the ontological problem-solving architecture, a family of persistence surveillance sensor systems and algorithms has been instantiated in a prototype environment to demonstrate the assignment of systems to subtasks of high-level missions. PMID:22164081

  11. Association of metal tolerance with multiple antibiotic resistance of bacteria isolated from drinking water

    SciTech Connect

    Calomiris, J.J.; Armstrong, J.L.; Seidler, R.J.

    1984-06-01

    Bacterial isolates from the drinking water system of an Oregon coastal community were examined to assess the association of metal tolerance with multiple antibiotic resistance. Positive correlations between tolerance to high levels of Cu/sup 2 +/, Pb/sup 2 +/, and Zn/sup 2 +/ and multiple antibiotic resistance were noted among bacteria from distribution waters but not among bacteria from raw waters. Tolerances to higher levels of Al/sup 3 +/ and Sn/sup 2 +/ were demonstrated more often by raw water isolates which were not typically multiple antibiotic resistant. A similar incidence of tolerance to Cd/sup 2 +/ was demonstrated by isolates of both water types and was not associated with multiple antibiotic resistance. These results suggest that simultaneous selection phenomena occurred in distribution water for bacteria which exhibited unique patterns of tolerance to Cu/sup 2 +/, Pb/sup 2 +/, and Zn/sup 2 +/ and antibiotic resistance.

  12. Integrated Corrosion Facility for long-term testing of candidate materials for high-level radioactive waste containment

    SciTech Connect

    Estill, J.C.; Dalder, E.N.C.; Gdowski, G.E.; McCright, R.D.

    1994-10-01

    A long-term-testing facility, the Integrated Corrosion Facility (I.C.F.), is being developed to investigate the corrosion behavior of candidate construction materials for high-level-radioactive waste packages for the potential repository at Yucca Mountain, Nevada. Corrosion phenomena will be characterized in environments considered possible under various scenarios of water contact with the waste packages. The testing of the materials will be conducted both in the liquid and high humidity vapor phases at 60 and 90{degrees}C. Three classes of materials with different degrees of corrosion resistance will be investigated in order to encompass the various design configurations of waste packages. The facility is expected to be in operation for a minimum of five years, and operation could be extended to longer times if warranted. A sufficient number of specimens will be emplaced in the test environments so that some can be removed and characterized periodically. The corrosion phenomena to be characterized are general, localized, galvanic, and stress corrosion cracking. The long-term data obtained from this study will be used in corrosion mechanism modeling, performance assessment, and waste package design. Three classes of materials are under consideration. The corrosion resistant materials are high-nickel alloys and titanium alloys; the corrosion allowance materials are low-alloy and carbon steels; and the intermediate corrosion resistant materials are copper-nickel alloys.

  13. Balamuthia mandrillaris exhibits metalloprotease activities.

    PubMed

    Matin, Abdul; Stins, Monique; Kim, Kwang Sik; Khan, Naveed Ahmed

    2006-06-01

    Balamuthia mandrillaris is a recently identified protozoan pathogen that can cause fatal granulomatous encephalitis. However, the pathogenesis and pathophysiology of B. mandrillaris encephalitis remain unclear. Because proteases may play a role in the central nervous system (CNS) pathology, we used spectrophotometric, cytopathic and zymographic assays to assess protease activities of B. mandrillaris. Using two clinical isolates of B. mandrillaris (from human and baboon), we observed that B. mandrillaris exhibits protease activities. Zymographic assays revealed major protease bands of approximate molecular weights in the region of 40-50 kDa on sodium dodecyl sulfate-polyacrylamide gels using gelatin as substrate. The protease bands were inhibited with 1,10-phenanthroline, suggesting metallo-type proteases. The proteolytic activities were observed over a pH range of 5-11 with maximum activity at neutral pH and at 42 degrees C. Balamuthia mandrillaris proteases exhibit properties to degrade extracellular matrix (ECM), which provide structural and functional support to the brain tissue. This is shown by degradation of collagen I and III (major components of collagenous ECM), elastin (elastic fibrils of ECM), plasminogen (involved in proteolytic degradation of ECM), as well as other substrates such as casein and gelatin but not haemoglobin. However, these proteases exhibited a minimal role in B. mandrillaris-mediated host cell death in vitro using human brain microvascular endothelial cells (HBMECs). This was shown using broad-spectrum matrix metalloprotease inhibitors, GM 6001 and GM 1489, which had no effect on B. mandrillaris-mediated HBMEC cytotoxicity. This is the first demonstration that B. mandrillaris exhibits metalloproteases, which may play important role(s) in the ECM degradation and thus in CNS pathology. PMID:16706791

  14. Assessment of high-level waste form conformance with proposed regulatory and repository criteria

    SciTech Connect

    Gordon, D E; Gray, P L; Jennings, A S; Permar, P H

    1982-04-01

    Federal regulatory criteria for geologic disposal of high-level waste are under development. Also, interim performance specifications for high-level waste forms in geologic isolation are being developed within the Federal program responsible for repository selection and operation. Two high-level waste forms, borosilicate glass and crystalline ceramic, have been selected as candidate immobilization forms for the Defense Waste Processing Facility (DWPF) which is to immobilize high-level wastes at the Savannah River Plant (SRP). An assessment of how these two waste forms conform with the proposed regulatory criteria and repository specifications was performed. Both forms were determined to be in conformance with postulated rules for radionuclide releases and radiation exposures throughout the entire waste disposal system, as well as with proposed repository operation requirements.

  15. Demonstration of Small Tank Tetraphenylborate Precipitation Process Using Savannah River Site High Level Waste

    SciTech Connect

    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.

  16. The Demographics of High-level and Recreational Athletes With Intra-articular Hip Injury

    PubMed Central

    Tibor, Lisa M.; Bedi, Asheesh; Oltean, Hanna N.; Gagnier, Joel Joseph; Kelly, Bryan T.

    2013-01-01

    Objectives: The pathoanatomy that causes femoroacetabular impingement (FAI) is common, but not everyone develops hip pain or arthrosis. Symptomatic FAI is likely due to a combination of anatomy and biomechanical demands, including sports participation. The primary purpose of this study was to determine demographic differences between high-level and recreational athletes undergoing hip arthroscopy. The secondary purpose of this study was to look at the demographics of high-level athletes grouped by sports with similar mechanical demands on the hip. We hypothesize that high-level and recreational athletes will differ by age, gender, and need for bilateral surgery. We also predict that demographics for high-level athletes will differ for sports with unique demands for hip kinematics. Methods: Using our hip preservation center registry, a retrospective review of prospectively collected data from patients undergoing hip arthroscopy between March 2010 and April 2012 was performed. Athletes were categorized as high-level (high school, collegiate, Olympic/international, or professional) or recreational. Subgroup analysis was performed for high-level athletes, looking at differences between contact, rotational running, impingement, overhead/asymmetric, endurance, and flexibility sports. Results: 288 high-level athletes and 334 recreational athletes were included. Being a high level athlete was associated with younger age (average age 20.2 vs 33.0, OR=0.69, P<0.001) and male gender (61.5% vs 53.6%, OR=1.75, P=0.03). The percentage of high-level athletes undergoing bilateral surgery was higher than for recreational athletes (28.4% vs 15.9%); however, this association was found to be confounded by age in multivariate analysis The most common sports for high-level athletes were soccer, hockey, and football. Athletes participating in rotational running sports were significantly younger than flexibility, contact, or impingement athletes. Similarly, endurance athletes were

  17. Immobilized high-level waste interim storage alternatives generation and analysis and decision report

    SciTech Connect

    CALMUS, R.B.

    1999-05-18

    This report presents a study of alternative system architectures to provide onsite interim storage for the immobilized high-level waste produced by the Tank Waste Remediation System (TWRS) privatization vendor. It examines the contract and program changes that have occurred and evaluates their impacts on the baseline immobilized high-level waste (IHLW) interim storage strategy. In addition, this report documents the recommended initial interim storage architecture and implementation path forward.

  18. Sunflower (Helianthus annuus) long-chain acyl-coenzyme A synthetases expressed at high levels in developing seeds.

    PubMed

    Aznar-Moreno, Jose A; Venegas Calerón, Mónica; Martínez-Force, Enrique; Garcés, Rafael; Mullen, Robert; Gidda, Satinder K; Salas, Joaquín J

    2014-03-01

    Long chain fatty acid synthetases (LACSs) activate the fatty acid chains produced by plastidial de novo biosynthesis to generate acyl-CoA derivatives, important intermediates in lipid metabolism. Oilseeds, like sunflower, accumulate high levels of triacylglycerols (TAGs) in their seeds to nourish the embryo during germination. This requires that sunflower seed endosperm supports very active glycerolipid synthesis during development. Sunflower seed plastids produce large amounts of fatty acids, which must be activated through the action of LACSs, in order to be incorporated into TAGs. We cloned two different LACS genes from developing sunflower endosperm, HaLACS1 and HaLACS2, which displayed sequence homology with Arabidopsis LACS9 and LACS8 genes, respectively. These genes were expressed at high levels in developing seeds and exhibited distinct subcellular distributions. We generated constructs in which these proteins were fused to green fluorescent protein and performed transient expression experiments in tobacco cells. The HaLACS1 protein associated with the external envelope of tobacco chloroplasts, whereas HaLACS2 was strongly bound to the endoplasmic reticulum. Finally, both proteins were overexpressed in Escherichia coli and recovered as active enzymes in the bacterial membranes. Both enzymes displayed similar substrate specificities, with a very high preference for oleic acid and weaker activity toward stearic acid. On the basis of our findings, we discuss the role of these enzymes in sunflower oil synthesis.

  19. High-level secretory expression and purification of unhydroxylated human collagen α1(III) chain in Pichia pastoris GS115.

    PubMed

    Li, Linbo; Fan, Daidi; Ma, Xiaoxuan; Deng, Jianjun; He, Jing

    2015-01-01

    Recombinant collagen and gelatin have been applied in biomedical materials field because of products from genetically engineered microorganisms with improved safety, traceability, reproducibility, and homogeneous quality. To obtain high-level secretory expression of single-chain full-length human collagen α1(III) chain (COL3A1) without the N and C telopeptides, the cDNA coding for the human COL3A1 gene was cloned into the secretory expression vector pPIC9K and integrated into Pichia pastoris GS115. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting analysis of culture supernatant from the recombinant methylotrophic yeast suggested that the unhydroxylated recombinant human COL3A1 (rhCOL3A1) was secreted into the culture medium, and exhibited an apparent molecular mass of approximately 130 kDa, which is 1.4 times higher than the theoretical one. Finally, the unhydroxylated rhCOL3A1 was purified to greater than 90% purity using a four-step approach. In addition, methylthiazolydiphenyl-tetrazolium bromide experiments indicated that low concentration of rhCOL3A1 could promote Baby hamster kidney cell (BHK21) proliferation effectively. The production and purification of rhCOL3A1 described in this study offer a new method for obtaining high level of rhCOL3A1 in relatively pure form, which is suitable for biomedical materials application. PMID:25231012

  20. Rapid High-Level Production of Functional HIV Broadly Neutralizing Monoclonal Antibodies in Transient Plant Expression Systems

    PubMed Central

    Rosenberg, Yvonne; Sack, Markus; Montefiori, David; Forthal, Donald; Mao, Lingjun; -Abanto, Segundo Hernandez; 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. PMID:23533588

  1. DEVELOPMENT OF AN IMPROVED SODIUM TITANATE FOR THE PRETREATMENT OF HIGH LEVEL NUCLEAR WASTE AT THE SAVANNAH RIVER SITE

    SciTech Connect

    Hobbs D. T.; Poirier, M. R.; Barnes, M. J.; Stallings, M. E.; Nyman, M. D.

    2005-11-22

    High-level nuclear waste produced from fuel reprocessing operations at the Savannah River Site (SRS) requires pretreatment to remove {sup 137}Cs, {sup 90}Sr and alpha-emitting radionuclides (i.e., actinides) prior to disposal onsite as low level waste. Separation processes planned at SRS include caustic side solvent extraction, for {sup 137}Cs removal, and sorption of {sup 90}Sr and alpha-emitting radionuclides onto monosodium titanate (MST). The predominant alpha-emitting radionuclides in the highly alkaline waste solutions include plutonium isotopes {sup 238}Pu, {sup 239}Pu and {sup 240}Pu. This paper describes recent results to produce an improved sodium titanate material that exhibits increased removal kinetics and capacity for {sup 90}Sr and alpha-emitting radionuclides compared to the baseline MST material.

  2. Advanced waste form and Melter development for treatment of troublesome high-level wastes

    SciTech Connect

    Marra, James; Kim, Dong -Sang; Maio, Vincent

    2015-10-01

    A number of waste components in US defense high level radioactive wastes (HLW) have proven challenging for current Joule heated ceramic melter (JHCM) operations and have limited the ability to increase waste loadings beyond already realized levels. Many of these “troublesome" waste species cause crystallization in the glass melt that can negatively impact product quality or have a deleterious effect on melter processing. Recent efforts at US Department of Energy laboratories have focused on understanding crystallization behavior within HLW glass melts and investigating approaches to mitigate the impacts of crystallization so that increases in waste loading can be realized. Advanced glass formulations have been developed to highlight the unique benefits of next-generation melter technologies such as the Cold Crucible Induction Melter (CCIM). Crystal-tolerant HLW glasses have been investigated to allow sparingly soluble components such as chromium to crystallize in the melter but pass out of the melter before accumulating.The Hanford site AZ-101 tank waste composition represents a waste group that is waste loading limited primarily due to high concentrations of Fe2O3 (also with high Al2O3 concentrations). Systematic glass formulation development utilizing slightly higher process temperatures and higher tolerance to spinel crystals demonstrated that an increase in waste loading of more than 20% could be achieved for this waste composition, and by extension higher loadings for wastes in the same group. An extended duration CCIM melter test was conducted on an AZ-101 waste simulant using the CCIM platform at the Idaho National Laboratory (INL). The melter was continually operated for approximately 80 hours demonstrating that the AZ-101 high waste loading glass composition could be readily processed using the CCIM technology. The resulting glass was close to the targeted composition and exhibited excellent durability in both

  3. Antibiotic resistance among cultured bacterial isolates from bioethanol fermentation facilities across the United States.

    PubMed

    Murphree, Colin A; Heist, E Patrick; Moe, Luke A

    2014-09-01

    Bacterial contamination of fuel ethanol fermentations by lactic acid bacteria (LAB) can have crippling effects on bioethanol production. Producers have had success controlling bacterial growth through prophylactic addition of antibiotics to fermentors, yet concerns have arisen about antibiotic resistance among the LAB. Here, we report on mechanisms used by 32 LAB isolates from eight different US bioethanol facilities to persist under conditions of antibiotic stress. Minimum inhibitory concentration assays with penicillin, erythromycin, and virginiamycin revealed broad resistance to each of the antibiotics as well as high levels of resistance to individual antibiotics. Phenotypic assays revealed that antibiotic inactivation mechanisms contributed to the high levels of individual resistances among the isolates, especially to erythromycin and virginiamycin, yet none of the isolates appeared to use a β-lactamase. Biofilm formation was noted among the majority of the isolates and may contribute to persistence under low levels of antibiotics. Nearly all of the isolates carried at least one canonical antibiotic resistance gene and many carried more than one. The erythromycin ribosomal methyltransferase (erm) gene class was found in 19 of 32 isolates, yet a number of these isolates exhibit little to no resistance to erythromycin. The erm genes were present in 15 isolates that encoded more than one antibiotic resistance mechanism, suggestive of potential genetic linkages. PMID:24748439

  4. Are Sewage Treatment Plants Promoting Antibiotic Resistance?

    EPA Science Inventory

    1. Introduction 1.1. How bacteria exhibit resistance 1.1.1. Resistance to -lactams 1.1.2. Resistance to sulphonamides and trimethoprim 1.1.3. Resistance to macrolides 1.1.4. Resistance to fluoroquinolones 1.1.5. Resistance to tetracyclines 1.1.6. Resistance to nitroimidaz...

  5. Antibiotic resistance among aquatic bacteria in natural freshwater environments of Korea.

    PubMed

    Kim, Tae Woon; Joung, Yochan; Han, Ji-Hye; Jung, Wonwha; Kim, Seung Bum

    2015-12-01

    The taxonomic diversity and antibiotic resistance among freshwater bacterial communities in the major water bodies of Korea was examined using 437 penicillin-resistant, and 110 tetracycline-resistant bacterial isolates. Based on 16S rRNA gene sequence analysis, most isolates were assigned to Proteobacteria, which was then followed by Bacteroidetes. Strains of Aeromonas were found as the most abundant penicillin-resistant populations, whereas those affiliated to diverse species including enteric groups were found as the most abundant tetracycline-resistant populations. Most strains exhibited multiple antibiotic resistance, and all tested strains were resistant to penicillin and hygromycin. High levels of resistance were observed for antibiotics acting on cell wall synthesis, whereas low levels were for those acting on DNA replication or transcription in general. It is apparent from this study that penicillin resistance is widespread among environmental bacteria, although the antibiotic has been generally non-detectable in the environment. It is also likely from the taxonomic composition of the resistant communities that various sources including terrestrial animals and humans may contribute to antibiotic resistance in the freshwater environment.

  6. Crows spontaneously exhibit analogical reasoning.

    PubMed

    Smirnova, Anna; Zorina, Zoya; Obozova, Tanya; Wasserman, Edward

    2015-01-19

    Analogical reasoning is vital to advanced cognition and behavioral adaptation. Many theorists deem analogical thinking to be uniquely human and to be foundational to categorization, creative problem solving, and scientific discovery. Comparative psychologists have long been interested in the species generality of analogical reasoning, but they initially found it difficult to obtain empirical support for such thinking in nonhuman animals (for pioneering efforts, see [2, 3]). Researchers have since mustered considerable evidence and argument that relational matching-to-sample (RMTS) effectively captures the essence of analogy, in which the relevant logical arguments are presented visually. In RMTS, choice of test pair BB would be correct if the sample pair were AA, whereas choice of test pair EF would be correct if the sample pair were CD. Critically, no items in the correct test pair physically match items in the sample pair, thus demanding that only relational sameness or differentness is available to support accurate choice responding. Initial evidence suggested that only humans and apes can successfully learn RMTS with pairs of sample and test items; however, monkeys have subsequently done so. Here, we report that crows too exhibit relational matching behavior. Even more importantly, crows spontaneously display relational responding without ever having been trained on RMTS; they had only been trained on identity matching-to-sample (IMTS). Such robust and uninstructed relational matching behavior represents the most convincing evidence yet of analogical reasoning in a nonprimate species, as apes alone have spontaneously exhibited RMTS behavior after only IMTS training.

  7. Collaborative virtual environments art exhibition

    NASA Astrophysics Data System (ADS)

    Dolinsky, Margaret; Anstey, Josephine; Pape, Dave E.; Aguilera, Julieta C.; Kostis, Helen-Nicole; Tsoupikova, Daria

    2005-03-01

    This panel presentation will exhibit artwork developed in CAVEs and discuss how art methodologies enhance the science of VR through collaboration, interaction and aesthetics. Artists and scientists work alongside one another to expand scientific research and artistic expression and are motivated by exhibiting collaborative virtual environments. Looking towards the arts, such as painting and sculpture, computer graphics captures a visual tradition. Virtual reality expands this tradition to not only what we face, but to what surrounds us and even what responds to our body and its gestures. Art making that once was isolated to the static frame and an optimal point of view is now out and about, in fully immersive mode within CAVEs. Art knowledge is a guide to how the aesthetics of 2D and 3D worlds affect, transform, and influence the social, intellectual and physical condition of the human body through attention to psychology, spiritual thinking, education, and cognition. The psychological interacts with the physical in the virtual in such a way that each facilitates, enhances and extends the other, culminating in a "go together" world. Attention to sharing art experience across high-speed networks introduces a dimension of liveliness and aliveness when we "become virtual" in real time with others.

  8. Crows spontaneously exhibit analogical reasoning.

    PubMed

    Smirnova, Anna; Zorina, Zoya; Obozova, Tanya; Wasserman, Edward

    2015-01-19

    Analogical reasoning is vital to advanced cognition and behavioral adaptation. Many theorists deem analogical thinking to be uniquely human and to be foundational to categorization, creative problem solving, and scientific discovery. Comparative psychologists have long been interested in the species generality of analogical reasoning, but they initially found it difficult to obtain empirical support for such thinking in nonhuman animals (for pioneering efforts, see [2, 3]). Researchers have since mustered considerable evidence and argument that relational matching-to-sample (RMTS) effectively captures the essence of analogy, in which the relevant logical arguments are presented visually. In RMTS, choice of test pair BB would be correct if the sample pair were AA, whereas choice of test pair EF would be correct if the sample pair were CD. Critically, no items in the correct test pair physically match items in the sample pair, thus demanding that only relational sameness or differentness is available to support accurate choice responding. Initial evidence suggested that only humans and apes can successfully learn RMTS with pairs of sample and test items; however, monkeys have subsequently done so. Here, we report that crows too exhibit relational matching behavior. Even more importantly, crows spontaneously display relational responding without ever having been trained on RMTS; they had only been trained on identity matching-to-sample (IMTS). Such robust and uninstructed relational matching behavior represents the most convincing evidence yet of analogical reasoning in a nonprimate species, as apes alone have spontaneously exhibited RMTS behavior after only IMTS training. PMID:25532894

  9. RESULTS OF THE FY09 ENHANCED DOE HIGH LEVEL WASTE MELTER THROUGHPUT STUDIES AT SRNL

    SciTech Connect

    Johnson, F.; Edwards, T.

    2010-06-23

    High-level waste (HLW) throughput (i.e., the amount of waste processed per unit time) is a function of two critical parameters: waste loading (WL) and melt rate. For the Waste Treatment and Immobilization Plant (WTP) at the Hanford Site and the Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS), increasing HLW throughput would significantly reduce the overall mission life cycle costs for the Department of Energy (DOE). The objective of this task is to develop data, assess property models, and refine or develop the necessary models to support increased WL of HLW at SRS. It is a continuation of the studies initiated in FY07, but is under the specific guidance of a Task Change Request (TCR)/Work Authorization received from DOE headquarters (Project Number RV071301). Using the data generated in FY07, FY08 and historical data, two test matrices (60 glasses total) were developed at the Savannah River National Laboratory (SRNL) in order to generate data in broader compositional regions. These glasses were fabricated and characterized using chemical composition analysis, X-ray Diffraction (XRD), viscosity, liquidus temperature (TL) measurement and durability as defined by the Product Consistency Test (PCT). The results of this study are summarized below: (1) In general, the current durability model predicts the durabilities of higher waste loading glasses quite well. A few of the glasses exhibited poorer durability than predicted. (2) Some of the glasses exhibited anomalous behavior with respect to durability (normalized leachate for boron (NL [B])). The quenched samples of FY09EM21-02, -07 and -21 contained no nepheline or other wasteform affecting crystals, but have unacceptable NL [B] values (> 10 g/L). The ccc sample of FY09EM21-07 has a NL [B] value that is more than one half the value of the quenched sample. These glasses also have lower concentrations of Al{sub 2}O{sub 3} and SiO{sub 2}. (3) Five of the ccc samples (EM-13, -14, -15, -29 and

  10. A Framework for Translating a High Level Security Policy into Low Level Security Mechanisms

    NASA Astrophysics Data System (ADS)

    Hassan, Ahmed A.; Bahgat, Waleed M.

    2010-01-01

    Security policies have different components; firewall, active directory, and IDS are some examples of these components. Enforcement of network security policies to low level security mechanisms faces some essential difficulties. Consistency, verification, and maintenance are the major ones of these difficulties. One approach to overcome these difficulties is to automate the process of translation of high level security policy into low level security mechanisms. This paper introduces a framework of an automation process that translates a high level security policy into low level security mechanisms. The framework is described in terms of three phases; in the first phase all network assets are categorized according to their roles in the network security and relations between them are identified to constitute the network security model. This proposed model is based on organization based access control (OrBAC). However, the proposed model extend the OrBAC model to include not only access control policy but also some other administrative security policies like auditing policy. Besides, the proposed model enables matching of each rule of the high level security policy with the corresponding ones of the low level security policy. Through the second phase of the proposed framework, the high level security policy is mapped into the network security model. The second phase could be considered as a translation of the high level security policy into an intermediate model level. Finally, the intermediate model level is translated automatically into low level security mechanism. The paper illustrates the applicability of proposed approach through an application example.

  11. Low-level awareness accompanies "unconscious" high-level processing during continuous flash suppression.

    PubMed

    Gelbard-Sagiv, Hagar; Faivre, Nathan; Mudrik, Liad; Koch, Christof

    2016-01-01

    The scope and limits of unconscious processing are a matter of ongoing debate. Lately, continuous flash suppression (CFS), a technique for suppressing visual stimuli, has been widely used to demonstrate surprisingly high-level processing of invisible stimuli. Yet, recent studies showed that CFS might actually allow low-level features of the stimulus to escape suppression and be consciously perceived. The influence of such low-level awareness on high-level processing might easily go unnoticed, as studies usually only probe the visibility of the feature of interest, and not that of lower-level features. For instance, face identity is held to be processed unconsciously since subjects who fail to judge the identity of suppressed faces still show identity priming effects. Here we challenge these results, showing that such high-level priming effects are indeed induced by faces whose identity is invisible, but critically, only when a lower-level feature, such as color or location, is visible. No evidence for identity processing was found when subjects had no conscious access to any feature of the suppressed face. These results suggest that high-level processing of an image might be enabled by-or co-occur with-conscious access to some of its low-level features, even when these features are not relevant to the processed dimension. Accordingly, they call for further investigation of lower-level awareness during CFS, and reevaluation of other unconscious high-level processing findings. PMID:26756173

  12. Extending Automatic Parallelization to Optimize High-Level Abstractions for Multicore

    SciTech Connect

    Liao, C; Quinlan, D J; Willcock, J J; Panas, T

    2008-12-12

    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. C++ applications using high-level abstractions, such as STL containers and complex user-defined 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 automatically parallelize C++ applications using ROSE, a multiple-language source-to-source compiler infrastructure which preserves the high-level abstractions and gives us access to their semantics. Several representative parallelization candidate kernels are used to explore semantic-aware parallelization strategies for high-level abstractions, combined with extended compiler analyses. Those kernels include an array-base computation loop, a loop with task-level parallelism, and a domain-specific tree traversal. Our work extends the applicability of automatic parallelization to modern applications using high-level abstractions and exposes more opportunities to take advantage of multicore processors.

  13. Screening and incorporation of rust resistance from Allium cepa into bunching onion (Allium fistulosum) via alien chromosome addition.

    PubMed

    Wako, Tadayuki; Yamashita, Ken-ichiro; Tsukazaki, Hikaru; Ohara, Takayoshi; Kojima, Akio; Yaguchi, Shigenori; Shimazaki, Satoshi; Midorikawa, Naoko; Sakai, Takako; Yamauchi, Naoki; Shigyo, Masayoshi

    2015-04-01

    Bunching onion (Allium fistulosum L.; 2n = 16), bulb onion (Allium cepa L. Common onion group), and shallot (Allium cepa L. Aggregatum group) cultivars were inoculated with rust fungus, Puccinia allii, isolated from bunching onion. Bulb onions and shallots are highly resistant to rust, suggesting they would serve as useful resources for breeding rust resistant bunching onions. To identify the A. cepa chromosome(s) related to rust resistance, a complete set of eight A. fistulosum - shallot monosomic alien addition lines (MAALs) were inoculated with P. allii. At the seedling stage, FF+1A showed a high level of resistance in controlled-environment experiments, suggesting that the genes related to rust resistance could be located on shallot chromosome 1A. While MAAL, multi-chromosome addition line, and hypoallotriploid adult plants did not exhibit strong resistance to rust. In contrast to the high resistance of shallot, the addition line FF+1A+5A showed reproducibly high levels of rust resistance. PMID:26218854

  14. Determination of total cyanide in Hanford Site high-level wastes

    SciTech Connect

    Winters, W.I.; Pool, K.H.

    1994-05-01

    Nickel ferrocyanide compounds (Na{sub 2-x}Cs{sub x}NiFe (CN){sub 6}) were produced in a scavenging process to remove {sup 137}Cs from Hanford Site single-shell tank waste supernates. Methods for determining total cyanide in Hanford Site high-level wastes are needed for the evaluation of potential exothermic reactions between cyanide and oxidizers such as nitrate and for safe storage, processing, and management of the wastes in compliance with regulatory requirements. Hanford Site laboratory experience in determining cyanide in high-level wastes is summarized. Modifications were made to standard cyanide methods to permit improved handling of high-level waste samples and to eliminate interferences found in Hanford Site waste matrices. Interferences and associated procedure modifications caused by high nitrates/nitrite concentrations, insoluble nickel ferrocyanides, and organic complexants are described.

  15. Predictors of High Level of Hostility among Homeless Men on Parole.

    PubMed

    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.

  16. The Savannah River Site Replacement High Level Radioactive Waste Evaporator Project

    SciTech Connect

    Presgrove, S.B.

    1992-08-01

    The Replacement High Level Waste Evaporator Project was conceived in 1985 to reduce the volume of the high level radioactive waste Process of the high level waste has been accomplished up to this time using Bent Tube type evaporators and therefore, that type evaporator was selected for this project. The Title I Design of the project was 70% completed in late 1990. The Department of Energy at that time hired an independent consulting firm to perform a complete review of the project. The DOE placed a STOP ORDER on purchasing the evaporator in January 1991. Essentially, no construction was to be done on this project until all findings and concerns dealing with the type and design of the evaporator are resolved. This report addresses two aspects of the DOE design review; (1) Comparing the Bent Tube Evaporator with the Forced Circulation Evaporator, (2) The design portion of the DOE Project Review - concentrated on the mechanical design properties of the evaporator. 1 ref.

  17. The Savannah River Site Replacement High Level Radioactive Waste Evaporator Project

    SciTech Connect

    Presgrove, S.B. )

    1992-01-01

    The Replacement High Level Waste Evaporator Project was conceived in 1985 to reduce the volume of the high level radioactive waste Process of the high level waste has been accomplished up to this time using Bent Tube type evaporators and therefore, that type evaporator was selected for this project. The Title I Design of the project was 70% completed in late 1990. The Department of Energy at that time hired an independent consulting firm to perform a complete review of the project. The DOE placed a STOP ORDER on purchasing the evaporator in January 1991. Essentially, no construction was to be done on this project until all findings and concerns dealing with the type and design of the evaporator are resolved. This report addresses two aspects of the DOE design review; (1) Comparing the Bent Tube Evaporator with the Forced Circulation Evaporator, (2) The design portion of the DOE Project Review - concentrated on the mechanical design properties of the evaporator. 1 ref.

  18. Results of a pilot antibiotic resistance survey of Albanian poultry farms.

    PubMed

    Alcaine, S D; Molla, L; Nugen, S R; Kruse, H

    2016-03-01

    Global dissemination of antibiotic-resistant bacteria in food animals is a major public health concern. Whilst many countries have implemented prudent antibiotic use policies and surveillance systems both in clinical and veterinary settings, there are no such systems in place in Albania and little is known about the levels of antibiotic-resistant bacteria in food animals within the country. A total of 172 poultry samples were taken from six Albanian farms over a 3-month period and were tested for the presence of Enterobacteriaceae. In total, 91 bacterial isolates were obtained and were characterised by species (Escherichia coli, Salmonella spp. or other Enterobacteriaceae) and by susceptibility to 11 antibiotics. Resistance rates of E. coli and Salmonella isolates were, respectively: amoxicillin (86%, 64%); chloramphenicol (77%, 82%); ciprofloxacin (93%, 73%); cefotaxime (14%, 0%); gentamicin (12%, 0%); kanamycin (30%, 18%); nalidixic acid (91%, 73%); streptomycin (70%, 55%); sulphonamides (91%, 73%); tetracycline (95%, 73%); and trimethoprim (79%, 64%). Multidrug resistance to at least four antibiotics was observed in 95% of E. coli isolates and 82% of Salmonella. In conclusion, these data indicate that: (i) Salmonella and E. coli isolates from Albanian poultry farms exhibit high to extremely high levels of antibiotic resistance; (ii) Salmonella and E. coli isolates exhibit resistance to multiple antibiotics; and (iii) multidrug resistance profiles among Enterobacteriaceae are geographically widespread. Implementation of prudent antibiotic use policies in food animals and related surveillance will be necessary to reduce the emergence, spread and establishment of highly resistant strains across poultry farms in Albania. PMID:27436396

  19. No fitness cost of glyphosate resistance endowed by massive EPSPS gene amplification in Amaranthus palmeri.

    PubMed

    Vila-Aiub, Martin M; Goh, Sou S; Gaines, Todd A; Han, Heping; Busi, Roberto; Yu, Qin; Powles, Stephen B

    2014-04-01

    Amplification of the EPSPS gene has been previously identified as the glyphosate resistance mechanism in many populations of Amaranthus palmeri, a major weed pest in US agriculture. Here, we evaluate the effects of EPSPS gene amplification on both the level of glyphosate resistance and fitness cost of resistance. A. palmeri individuals resistant to glyphosate by expressing a wide range of EPSPS gene copy numbers were evaluated under competitive conditions in the presence or absence of glyphosate. Survival rates to glyphosate and fitness traits of plants under intra-specific competition were assessed. Plants with higher amplification of the EPSPS gene (53-fold) showed high levels of glyphosate resistance, whereas less amplification of the EPSPS gene (21-fold) endowed a lower level of glyphosate resistance. Without glyphosate but under competitive conditions, plants exhibiting up to 76-fold EPSPS gene amplification exhibited similar height, and biomass allocation to vegetative and reproductive organs, compared to glyphosate susceptible A. palmeri plants with no amplification of the EPSPS gene. Both the additive effects of EPSPS gene amplification on the level of glyphosate resistance and the lack of associated fitness costs are key factors contributing to EPSPS gene amplification as a widespread and important glyphosate resistance mechanism likely to become much more evident in weed plant species.

  20. High-Level Clouds and Relation to Sea Surface Temperature as Inferred from Japan's GMS Measurements

    NASA Technical Reports Server (NTRS)

    Chou, Ming-Dah; Lindzen, Richard S.; Lee, Kyu-Tae; Einaudi, Franco (Technical Monitor)

    2000-01-01

    High-level clouds have a significant impact on the radiation energy budgets and, hence, the climate of the Earth. Convective cloud systems, which are controlled by large-scale thermal and dynamical conditions, propagate rapidly within days. At this time scale, changes of sea surface temperature (SST) are small. Radiances measured by Japan's Geostationary Meteorological Satellite (GMS) are used to study the relation between high-level clouds and SST in the tropical western and central Pacific (30 S-30 N; 130 E-170 W), where the ocean is warm and deep convection is intensive. Twenty months (January 1998 - August, 1999) of GMS data are used, which cover the second half of the strong 1997-1998 El Nino. Brightness temperature at the 11-micron channel is used to identify high-level clouds. The core of convection is identified based on the difference in the brightness temperatures of the 11- and 12-micron channels. Because of the rapid movement of clouds, there is little correlation between clouds six hours apart. When most of deep convection moves to regions of high SST, the domain averaged high-level cloud amount decreases. A +2C change of SST in cloudy regions results in a relative change of -30% in high-level cloud amount. This large change in cloud amount is due to clouds moving from cool regions to warm regions but not the change in SST itself. A reduction in high-level cloud amount in the equatorial region implies an expanded dry upper troposphere in the off-equatorial region, and the greenhouse warming of high clouds and water vapor is reduced through enhanced longwave cooling to space. The results are important for understanding the physical processes relating SST, convection, and water vapor in the tropics. They are also important for validating climate simulations using global general circulation models.

  1. Susceptibility of HPV16 and 18 to high level disinfectants indicated for semi‐critical ultrasound probes

    PubMed Central

    Ryndock, Eric; Robison, Richard

    2015-01-01

    Ultrasound probes used in endocavitary procedures have been shown to be contaminated with high‐risk HPV after routine use and HPV is also known to be resistant to some high level disinfectants (HLDs). This study compared efficacy of two leading ultrasound probe HLD methods; liquid ortho‐phthalaldehyde (Cidex® OPA) and an automated device using sonicated hydrogen peroxide (trophon® EPR) against HPV16 and HPV18 in a hard‐surface carrier test. Native HPV16 and HPV18 virions were generated in organotypic epithelial raft cultures. Viral lysates were dried onto carriers with a 5% (v/v) protein soil. Efficacy tests were performed against the automated device at 35% and 31.5% H2O2 and 0.55% OPA in quadruplicate with matched input, neutralization, and cytotoxicity controls. Hypochlorite was included as a positive control. Infectivity was determined by the abundance (qRT‐PCR) of the spliced E1^E4 transcript in infected recipient cells. The automated HLD device showed excellent efficacy against HPV16 and HPV18 (>5 log10 reductions in infectivity) whereas OPA showed minimal efficacy (<0.6 log10 reductions). While HPV is highly resistant to OPA, sonicated hydrogen peroxide offers an effective disinfection solution for ultrasound probes. Disinfection methods that are effective against HPV should be adopted where possible. J. Med. Virol. 88:1076–1080, 2016. © 2015 The Authors. Journal of Medical Virology Published by Wiley Periodicals, Inc. PMID:26519866

  2. Rapid selection using G418 of high copy number transformants of Pichia pastoris for high-level foreign gene expression.

    PubMed

    Scorer, C A; Clare, J J; McCombie, W R; Romanos, M A; Sreekrishna, K

    1994-02-01

    Pichia pastoris is a methylotrophic yeast increasingly important in the production of therapeutic proteins. Expression vectors are based on the methanol-inducible AOX1 promoter and are integrated into the host chromosome. In most cases high copy number integration has been shown to be important for high-level expression. Since this occurs at low frequency during transformation, we previously used DNA dot blot screens to identify suitable clones. In this paper we report the use of vectors containing the Tn903 kanr gene conferring G418-resistance. Initial experiments demonstrated that copy number showed a tight correlation with drug-resistance. Using a G418 growth inhibition screen, we readily isolated a series of transformants, containing progressively increasing numbers (1 to 12) of a vector expressing HIV-1 ENV, which we used to examine the relationship between copy number and foreign mRNA levels. Northern blot analysis indicated that ENV mRNA levels from a single-copy clone were nearly as high as AOX1 mRNA, and increased progressively with increasing copy number so as to greatly exceed AOX1 mRNA. We have also developed protocols for the selection, using G418, of high copy number transformants following spheroplast transformation or electroporation. We anticipate that these protocols will simplify the use of Pichia as a biotechnological tool.

  3. Tank waste remediation system phase I high-level waste feed processability assessment report

    SciTech Connect

    Lambert, S.L.; Stegen, G.E., Westinghouse Hanford

    1996-08-01

    This report evaluates the effects of feed composition on the Phase I high-level waste immobilization process and interim storage facility requirements for the high-level waste glass.Several different Phase I staging (retrieval, blending, and pretreatment) scenarios were used to generate example feed compositions for glass formulations, testing, and glass sensitivity analysis. Glass models and data form laboratory glass studies were used to estimate achievable waste loading and corresponding glass volumes for various Phase I feeds. Key issues related to feed process ability, feed composition, uncertainty, and immobilization process technology are identified for future consideration in other tank waste disposal program activities.

  4. The radiation characteristics of the transport packages with vitrified high-level waste

    NASA Astrophysics Data System (ADS)

    Bogatov, S. A.; Mitenkova, E. F.; Novikov, N. V.

    2015-12-01

    The calculation method of neutron yield in the (α, n) reaction for a homogeneous material of arbitrary composition is represented. It is shown that the use of the ORIGEN 2 code excluding the real elemental composition of vitrified high-level waste leads to significant underestimation of the neutron yield in the (α, n) reaction. For vitrified high-level waste and spent nuclear fuel from VVER, the neutron fluxes are analyzed. The thickness of the protective materials for a transfer cask and a shipping cask with vitrified highlevel waste are estimated.

  5. Avoiding the zero sum game in global cancer policy: beyond 2011 UN high level summit.

    PubMed

    Sullivan, R; Purushotham, A D

    2011-11-01

    In September 2011 a unique high level summit on non-communicable diseases will be held in New York. For cancer as for many of the other chronic diseases this marks their first high level recognition. However, the reality of cancer control in middle and low income countries is and will be very different from the trajectory experienced by developed countries. This perspective seeks to critically examine the approach being taken, mapping pitfalls and presenting alternative solutions for an international cancer control policy. PMID:22018537

  6. The radiation characteristics of the transport packages with vitrified high-level waste

    SciTech Connect

    Bogatov, S. A.; Mitenkova, E. F. Novikov, N. V.

    2015-12-15

    The calculation method of neutron yield in the (α, n) reaction for a homogeneous material of arbitrary composition is represented. It is shown that the use of the ORIGEN 2 code excluding the real elemental composition of vitrified high-level waste leads to significant underestimation of the neutron yield in the (α, n) reaction. For vitrified high-level waste and spent nuclear fuel from VVER, the neutron fluxes are analyzed. The thickness of the protective materials for a transfer cask and a shipping cask with vitrified highlevel waste are estimated.

  7. Talc-silicon glass-ceramic waste forms for immobilization of high- level calcined waste

    SciTech Connect

    Vinjamuri, K.

    1993-06-01

    Talc-silicon glass-ceramic waste forms are being evaluated as candidates for immobilization of the high level calcined waste stored onsite at the Idaho Chemical Processing Plant. These glass-ceramic waste forms were prepared by hot isostatically pressing a mixture of simulated nonradioactive high level calcined waste, talc, silicon and aluminum metal additives. The waste forms were characterized for density, chemical durability, and glass and crystalline phase compositions. The results indicate improved density and chemical durability as the silicon content is increased.

  8. Adapting high-level language programs for parallel processing using data flow

    NASA Technical Reports Server (NTRS)

    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.

  9. Impact of transporting defense high-level waste to a geologic repository

    SciTech Connect

    Joy, D.S.; Shappert, L.B.; Boyle, J.W.

    1984-08-01

    This transportation study assumes that defense high-level waste is stored in three locations (the Savannah River, Hanford, and Idaho Falls plants) and may be disposed of in (1) a commercial repository or (2) a defense-only repository, either of which could be located at one of the five candidate sites; also documented is a preliminary analysis of the costs and risks of transporting defense high-level waste from the three storage sites to the five potential candidate repository sites. 17 references, 4 figures, 27 tables.

  10. Solvent extraction in the treatment of acidic high-level liquid waste : where do we stand?

    SciTech Connect

    Horwitz, E. P.; Schulz, W. W.

    1998-06-18

    During the last 15 years, a number of solvent extraction/recovery processes have been developed for the removal of the transuranic elements, {sup 90}Sr and {sup 137}Cs from acidic high-level liquid waste. These processes are based on the use of a variety of both acidic and neutral extractants. This chapter will present an overview and analysis of the various extractants and flowsheets developed to treat acidic high-level liquid waste streams. The advantages and disadvantages of each extractant along with comparisons of the individual systems are discussed.

  11. High-level seismic response and failure prediction methods for piping

    SciTech Connect

    Severud, L.K.; Anderson, M.J.; Lindquist, M.R.; Wagner, S.E.; Weiner, E.O.

    1988-01-01

    Seismic response and failure analyses were performed for four piping systems that were shake-tested to high level nonlinear and inelastic response levels. Both pre- and post-test analyses were accomplished. A number of simplified elastic, elasto-plastic, and inelastic transient dynamic analysis methods were utilized. Descriptions of these methods, with their special structural parameters and comparisons of predictions using each method to test data, are provided. Reasonably useful, but conservative, methods were found for predicting the high-level inelastic response and the failure modes.

  12. Review of recent Chinese research on field dependence-independence in high-level athletes.

    PubMed

    Liu, W H

    1996-12-01

    A review of seven studies in China concerning field dependence-independence among 500 athletes in 10 different sports is presented. Athletes participating in closed-skill sports were more field-independent than those in open-skill sports. In closed-skill sports, high-level athletes were more field-independent than those of medium level. In open-skill sports involving direct contact, high-level athletes were more field-dependent than those of medium level. No significant relationship was found between field dependence-independence and athletes' performance in open skill sports in which no direct contact was involved. PMID:9017730

  13. Biofeedback to facilitate unassisted ventilation in individuals with high-level quadriplegia. A case report.

    PubMed

    Morrison, S A

    1988-09-01

    The purpose of this case report is to discuss the effectiveness of electromyographic biofeedback in reeducating and strengthening the accessory breathing muscles in an individual with high-level (C1) complete quadriplegia. Six unassisted breathing sessions were performed with EMG biofeedback intervention. Six unassisted breathing sessions without EMG biofeedback intervention were also performed. In both conditions, the subject's vital capacity and the amount of time of unassisted ventilation were recorded. The study results indicated that EMG biofeedback may be a helpful modality in training accessory breathing muscles to enable an individual with high-level quadriplegia to become independent of mechanical ventilation for varying amounts of time.

  14. Transgenic wheat expressing a barley UDP-glucosyltransferase detoxifies deoxynivalenol and provides high levels of resistance to Fusarium graminearum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium head blight (FHB), mainly caused by Fusarium graminearum, is a devastating disease of wheat and barley that results in huge economic losses worldwide. During infection, F. graminearum produces trichothecene mycotoxins, such as deoxynivalenol (DON), that increase fungal virulence and decreas...

  15. Inheritance of Resistance to Powdery Mildew Race 1W in Watermelon.

    PubMed

    Ben-Naim, Yariv; Cohen, Yigal

    2015-11-01

    Powdery mildew caused by Podosphaera xanthii is a major disease of watermelon in Israel. In this study, 291 accessions of Citrullus spp. were evaluated for resistance against P. xanthii race 1W. Only eight accessions exhibited high level of resistance. Inheritance of resistance against P. xanthii race 1W was studied by crossing three resistant accession of Citrullus lanatus var. citroides BIU 119, PI 189225, or PI 482312 with the susceptible cultivar 'Malali' or 'Sugar Baby'. Parents, F1, F2, and back cross progenies were evaluated for resistance in growth chambers at the cotyledon stage and the 4-leaf stage and in the field, at the 15-leaf stage. Resistance at the cotyledon stage was controlled by a single, partially dominant gene, whereas at the 4-leaf stage or the 15-leaf stage resistance was controlled by three complimentary, partially dominant genes. Crosses made among these resistant accessions revealed that BIU 119 and PI 189225 carry the same genes for resistance, whereas PI 482312 shares two out of three genes with both BIU 119 and PI 189225. A breeding line with high resistance level and good fruit qualities was developed from BIU 119 × HA5500.

  16. Inheritance of Resistance to Powdery Mildew Race 1W in Watermelon.

    PubMed

    Ben-Naim, Yariv; Cohen, Yigal

    2015-11-01

    Powdery mildew caused by Podosphaera xanthii is a major disease of watermelon in Israel. In this study, 291 accessions of Citrullus spp. were evaluated for resistance against P. xanthii race 1W. Only eight accessions exhibited high level of resistance. Inheritance of resistance against P. xanthii race 1W was studied by crossing three resistant accession of Citrullus lanatus var. citroides BIU 119, PI 189225, or PI 482312 with the susceptible cultivar 'Malali' or 'Sugar Baby'. Parents, F1, F2, and back cross progenies were evaluated for resistance in growth chambers at the cotyledon stage and the 4-leaf stage and in the field, at the 15-leaf stage. Resistance at the cotyledon stage was controlled by a single, partially dominant gene, whereas at the 4-leaf stage or the 15-leaf stage resistance was controlled by three complimentary, partially dominant genes. Crosses made among these resistant accessions revealed that BIU 119 and PI 189225 carry the same genes for resistance, whereas PI 482312 shares two out of three genes with both BIU 119 and PI 189225. A breeding line with high resistance level and good fruit qualities was developed from BIU 119 × HA5500. PMID:26267543

  17. Molecular characterisation of the clonal emergence of high-level ciprofloxacin-monoresistant Haemophilus influenzae in the Region of Southern Denmark.

    PubMed

    Fuursted, Kurt; Hartmeyer, Gitte Nyvang; Stegger, Marc; Andersen, Paal Skytt; Justesen, Ulrik Stenz

    2016-06-01

    Haemophilus influenzae is an important human pathogen usually susceptible to quinolones. Here we report the emergence of high-level ciprofloxacin-monoresistant H. influenzae in the Region of Southern Denmark. Four isolates were collected for phenotypic and molecular characterisation using whole-genome sequencing (WGS). During an 18-month period, the occurrence of high-level ciprofloxacin-monoresistant H. influenzae in patients aged 1-77 years from sputum, ear and eye samples was detected. An epidemiological link between the patients could not be identified. The isolates were non-encapsulated, biotype III and were demonstrated by WGS to be clonal belonging to a single clade with an unknown multilocus sequence type (double-locus variant of ST196). The antibiogram demonstrated that they were all monoresistant to ciprofloxacin with a minimum inhibitory concentration (MIC) >32mg/L. In silico resistome analysis revealed identical, both previously characterised and novel, putative resistance-related mutations in gyrA (S84L and D88N), parC (K20R, S84I, D356A or T356A, and M481I) and parE (E151K, I159A, D420N and S599A) in all isolates. The isolates were otherwise negative for any resistance genes. This is the first description of the clonal emergence of high-level monoresistant H. influenzae due to amino acid substitutions in gyrA, parC and parE. PMID:27436470

  18. Molecular characterisation of the clonal emergence of high-level ciprofloxacin-monoresistant Haemophilus influenzae in the Region of Southern Denmark.

    PubMed

    Fuursted, Kurt; Hartmeyer, Gitte Nyvang; Stegger, Marc; Andersen, Paal Skytt; Justesen, Ulrik Stenz

    2016-06-01

    Haemophilus influenzae is an important human pathogen usually susceptible to quinolones. Here we report the emergence of high-level ciprofloxacin-monoresistant H. influenzae in the Region of Southern Denmark. Four isolates were collected for phenotypic and molecular characterisation using whole-genome sequencing (WGS). During an 18-month period, the occurrence of high-level ciprofloxacin-monoresistant H. influenzae in patients aged 1-77 years from sputum, ear and eye samples was detected. An epidemiological link between the patients could not be identified. The isolates were non-encapsulated, biotype III and were demonstrated by WGS to be clonal belonging to a single clade with an unknown multilocus sequence type (double-locus variant of ST196). The antibiogram demonstrated that they were all monoresistant to ciprofloxacin with a minimum inhibitory concentration (MIC) >32mg/L. In silico resistome analysis revealed identical, both previously characterised and novel, putative resistance-related mutations in gyrA (S84L and D88N), parC (K20R, S84I, D356A or T356A, and M481I) and parE (E151K, I159A, D420N and S599A) in all isolates. The isolates were otherwise negative for any resistance genes. This is the first description of the clonal emergence of high-level monoresistant H. influenzae due to amino acid substitutions in gyrA, parC and parE.

  19. Molecular characterization of fluoroquinolone-resistant Aeromonas spp. isolated from imported shrimp.

    PubMed

    Shakir, Zakiya; Khan, Saeed; Sung, Kidon; Khare, Sangeeta; Khan, Ashraf; Steele, Roger; Nawaz, Mohamed

    2012-11-01

    Sixty-three nalidixic acid-resistant Aeromonas sp. isolates were obtained from imported shrimp. Phylogenetic analysis of gyrB sequences indicated that 18 were A. enteropelogenes, 26 were A. caviae, and 19 were A. sobria. Double missense mutations in the quinolone resistance-determining region (QRDR) of gyrA at codon 83 (Ser→Val/Ile) and codon 92 (Leu→Met) coupled with a point mutation of parC at codon 80 (Ser→Ile/Phe) conferred high levels of quinolone resistance in the isolates. A majority of A. enteropelogenes and A. caviae strains harbored toxin genes, whereas only a few A. sobria strains harbored these genes. The fluoroquinolone-resistant Aeromonas spp. exhibited higher cytotoxicity than fluoroquinolone-sensitive, virulent Aeromonas spp. to rat epithelial cells.

  20. Effects of Crowding and Attention on High-Levels of Motion Processing and Motion Adaptation

    PubMed Central

    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