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Sample records for aliivibrio salmonicida strain

  1. Recombinant expression and purification of an ATP-dependent DNA ligase from Aliivibrio salmonicida.

    PubMed

    Williamson, Adele; Pedersen, Hege

    2014-05-01

    The genome of the psychrophilic fish-pathogen Aliivibrio salmonicida encodes a putative ATP-dependent DNA ligase in addition to a housekeeping NAD-dependent enzyme. In order to study the structure and activity of the ATP dependent ligase in vitro we have undertaken its recombinant production and purification from an Escherichia coli based expression system. Expression and purification of this protein presented two significant challenges. First, the gene product was moderately toxic to E. coli cells, second it was necessary to remove the large amounts of E. coli DNA present in bacterial lysates without contamination of the protein preparation by nucleases which might interfere with future assaying. The toxicity problem was overcome by fusion of the putative ligase to large solubility tags such as maltose-binding protein (MBP) or Glutathione-S-transferase (GST), and DNA was removed by treatment with a nuclease which could be inhibited by reducing agents. As the A. salmonicida ATP-dependent DNA ligase gene encodes a predicted leader peptide, both the full-length and mature forms of the protein were produced. Both possessed ATP-dependent DNA ligase activity, but the truncated form was significantly more active. Here we detail the first reported production, purification and preliminary characterization of active A. salmonicida ATP-dependent DNA ligase.

  2. LitR Is a Repressor of syp Genes and Has a Temperature-Sensitive Regulatory Effect on Biofilm Formation and Colony Morphology in Vibrio (Aliivibrio) salmonicida

    PubMed Central

    Bjelland, Ane Mohn; Ronessen, Maria; Robertsen, Espen; Willassen, Nils Peder

    2014-01-01

    Vibrio (Aliivibrio) salmonicida is the etiological agent of cold water vibriosis, a disease in farmed Atlantic salmon (Salmo salar) that is kept under control due to an effective vaccine. A seawater temperature below 12°C is normally required for disease development. Quorum sensing (QS) is a cell density-regulated communication system that bacteria use to coordinate activities involved in colonization and pathogenesis, and we have previously shown that inactivation of the QS master regulator LitR attenuates the V. salmonicida strain LFI1238 in a fish model. We show here that strain LFI1238 and a panel of naturally occurring V. salmonicida strains are poor biofilm producers. Inactivation of litR in the LFI1238 strain enhances medium- and temperature-dependent adhesion, rugose colony morphology, and biofilm formation. Chemical treatment and electron microscopy of the biofilm identified an extracellular matrix consisting mainly of a fibrous network, proteins, and polysaccharides. Further, by microarray analysis of planktonic and biofilm cells, we identified a number of genes regulated by LitR and, among these, were homologues of the Vibrio fischeri symbiosis polysaccharide (syp) genes. The syp genes were regulated by LitR in both planktonic and biofilm lifestyle analyses. Disruption of syp genes in the V. salmonicida ΔlitR mutant alleviated adhesion, rugose colony morphology, and biofilm formation. Hence, LitR is a repressor of syp transcription that is necessary for expression of the phenotypes examined. The regulatory effect of LitR on colony morphology and biofilm formation is temperature sensitive and weak or absent at temperatures above the bacterium's upper threshold for pathogenicity. PMID:24973072

  3. Expression profiling reveals Spot 42 small RNA as a key regulator in the central metabolism of Aliivibrio salmonicida

    PubMed Central

    2012-01-01

    Background Spot 42 was discovered in Escherichia coli nearly 40 years ago as an abundant, small and unstable RNA. Its biological role has remained obscure until recently, and is today implicated in having broader roles in the central and secondary metabolism. Spot 42 is encoded by the spf gene. The gene is ubiquitous in the Vibrionaceae family of gamma-proteobacteria. One member of this family, Aliivibrio salmonicida, causes cold-water vibriosis in farmed Atlantic salmon. Its genome encodes Spot 42 with 84% identity to E. coli Spot 42. Results We generated a A. salmonicida spf deletion mutant. We then used microarray and Northern blot analyses to monitor global effects on the transcriptome in order to provide insights into the biological roles of Spot 42 in this bacterium. In the presence of glucose, we found a surprisingly large number of ≥ 2X differentially expressed genes, and several major cellular processes were affected. A gene encoding a pirin-like protein showed an on/off expression pattern in the presence/absence of Spot 42, which suggests that Spot 42 plays a key regulatory role in the central metabolism by regulating the switch between fermentation and respiration. Interestingly, we discovered an sRNA named VSsrna24, which is encoded immediately downstream of spf. This new sRNA has an expression pattern opposite to that of Spot 42, and its expression is repressed by glucose. Conclusions We hypothesize that Spot 42 plays a key role in the central metabolism, in part by regulating the pyruvat dehydrogenase enzyme complex via pirin. PMID:22272603

  4. Expression and characterization of a codon-optimized alkaline-stable carbonic anhydrase from Aliivibrio salmonicida for CO2 sequestration applications.

    PubMed

    Jun, So-Young; Kim, Sung Ho; Kanth, Bashista Kumar; Lee, Jinwon; Pack, Seung Pil

    2017-03-01

    The CO2 mineralization process, accelerated by carbonic anhydrase (CA) was proposed for the efficient capture and storage of CO2, the accumulation of which in the atmosphere is the main cause of global warming. Here, we characterize a highly stable form of the cloned CA from the Gram-negative marine bacterium Aliivibrio salmonicida, named ASCA that can promote CO2 absorption in an alkaline solvent required for efficient carbon capture. We designed a mature form of ASCA (mASCA) using a codon optimization of ASCA gene and removal of ASCA signal peptide. mASCA was highly expressed (255 mg/L) with a molecular weight of approximately 26 kDa. The mASCA enzyme exhibited stable esterase activity within a temperature range of 10-60 °C and a pH range of 6-11. mASCA activity remained stable for 48 h at pH 10. We also investigated its inhibition profiles using inorganic anions, such as acetazolamide, sulfanilamide, iodide, nitrate, and azide. We also demonstrate that mASCA is capable of catalyzing the conversion of CO2 to CaCO3 (calcite form) in the presence of Ca(2+). It should be noted that mASCA enzyme exhibits high production yield and sufficient stabilities against relatively high temperature and alkaline pH, which are required conditions for the development of more efficient enzymatic CCS systems.

  5. Infection of sea lamprey with an unusual strain of Aeromonas salmonicida

    USGS Publications Warehouse

    Diamanka, Arfang; Loch, Thomas P.; Cipriano, Rocco C.; Winters, Andrew D.; Faisal, Mohamed

    2014-01-01

    The invasion of the Laurentian Great Lakes by the fish-parasitic sea lamprey has led to catastrophic consequences, including the potential introduction of fish pathogens. Aeromonas salmonicida is a bacterial fish pathogen that causes devastating losses worldwide. Currently, there are five accepted subspecies of Aeromonas salmonicida: A. salmonicida subsp. salmonicida, masoucida, smithia, achromogenes, and pectinolytica. We discuss the discovery of an isolate of A. salmonicida that is pathogenic to rainbow trout (Oncorhynchus mykiss) and exhibits unique phenotypic and molecular characteristics. We examined 181 adult sea lamprey (Petromyzon marinus) from the Humber River (Lake Ontario watershed) and 162 adult sea lamprey from Duffins Creek (Lake Ontario watershed) during the spring seasons of 2005–11. Among those, 4/343 (1.2%) sea lamprey were culture positive for A. salmonicida, whereby biochemical and molecular studies identified three of the isolates as A. salmonicida subsp. salmonicida. The remaining isolate (As-SL1) recovered from Humber River sea lamprey was phenotypically more similar to A. salmonicida subsp. salmonicida than to the four other A. salmonicida subspecies. However, unlike A. salmonicida subsp. salmonicida, As-SL1 was sucrose positive, produced an acid-over-acid reaction on triple-sugar iron medium and did not amplify with A. salmonicida subsp. salmonicida specific primers. Phylogenetic analysis based on partial stretches of the 16S rRNA and DNA gyrase subunit B genes further confirmed that the As-SL1 isolate was not A. salmonicida subsp. masoucida, smithia, achromogenes, or pectinolytica. Based on our analyses, the As-SL1 isolate is either an unusual strain of A. salmonicida subsp. salmonicida or a novel A. salmonicida subspecies. The four A. salmonicida isolates that were recovered from sea lamprey were pathogenic to rainbow trout in experimental challenge studies. Our study also underscores the potential role of sea lamprey in the ecology of

  6. Draft Genome Sequence of Pseudomonas fluorescens ML11A, an Endogenous Strain from Brook Charr with Antagonistic Properties against Aeromonas salmonicida subsp. salmonicida

    PubMed Central

    Charette, Steve J.; Derome, Nicolas

    2017-01-01

    ABSTRACT Pseudomonas fluorescens ML11A, isolated from brook charr, showed a strong in vitro inhibitory effect against Aeromonas salmonicida subsp. salmonicida, a bacterial fish pathogen. Its genome harbors gene clusters for siderophore and bacteriocin biosynthesis and shares 99% whole-genome identity with P. fluorescens A506, a biological control strain used in agriculture. PMID:28254983

  7. Draft Genome Sequence of Aliivibrio fischeri Strain 5LC, a Bacterium Retrieved from Gilthead Sea Bream (Sparus aurata) Larvae Reared in Aquaculture.

    PubMed

    Califano, Gianmaria; Franco, Telma; Gonçalves, Ana C S; Castanho, Sara; Soares, Florbela; Ribeiro, Laura; Mata, Leonardo; Costa, Rodrigo

    2015-06-04

    To shed light on the putative host-mediated lifestyle of the quintessential marine symbiont Aliivibrio fischeri, and on the symbiosis versus potentially pathogenic features of bacteria associated with farmed fish, we report the draft genome sequence of A. fischeri strain 5LC, a bacterium retrieved from gilthead sea bream (Sparus aurata) larvae.

  8. Draft Genome Sequence of Aliivibrio fischeri Strain 5LC, a Bacterium Retrieved from Gilthead Sea Bream (Sparus aurata) Larvae Reared in Aquaculture

    PubMed Central

    Califano, Gianmaria; Franco, Telma; Gonçalves, Ana C. S.; Castanho, Sara; Soares, Florbela; Ribeiro, Laura; Mata, Leonardo

    2015-01-01

    To shed light on the putative host-mediated lifestyle of the quintessential marine symbiont Aliivibrio fischeri, and on the symbiosis versus potentially pathogenic features of bacteria associated with farmed fish, we report the draft genome sequence of A. fischeri strain 5LC, a bacterium retrieved from gilthead sea bream (Sparus aurata) larvae. PMID:26044435

  9. Draft genome sequence of the Chilean isolate Aeromonas salmonicida strain CBA100.

    PubMed

    Valdes, Natalia; Espinoza, Carolina; Sanhueza, Loreto; Gonzalez, Alex; Corsini, Gino; Tello, Mario

    2015-03-01

    We report the draft genome sequence from Aeromonas salmonicida sp. strain CBA100, which was characterized as an antibiotic-resistant bacterium isolated from infected rainbow trout. The total size of the genome is 4,788,109 bp, with a G + C content of 60.55%. Comparison of its open reading frames shows that the closest homologue to one third of the genes of strain CBA100 are found in A. hydrophila. The strain contains several efflux pumps and putative genes that confer resistance to multiclass antibiotics, including macrolide, β-lactamics, florfenicol and quinolones. The antibiogram profile suggests that efflux pumps are the main mechanism of resistance to non-β-lactamic antibiotics. This is the first genome of a Chilean isolate of A. salmonicida, which should shed light on the design of strain-specific vaccines against this pathogen and reduce the use of antibiotics for preventive treatment in Chilean aquaculture. © FEMS 2014. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  10. Clustering subspecies of Aeromonas salmonicida using IS630 typing

    PubMed Central

    2013-01-01

    Background The insertion element IS630 found in Aeromonas salmonicida belongs to the IS630-Tc1-mariner superfamily of transposons. It is present in multiple copies and represents approximately half of the IS present in the genome of A. salmonicida subsp. salmonicida A449. Results By using High Copy Number IS630 Restriction Fragment Length Polymorphism (HCN-IS630-RFLP), strains of various subspecies of Aeromonas salmonicida showed conserved or clustering patterns, thus allowing their differentiation from each other. Fingerprints of A. salmonicida subsp. salmonicida showed the highest homogeneity while ‘atypical’ A. salmonicida strains were more heterogeneous. IS630 typing also differentiated A. salmonicida from other Aeromonas species. The copy number of IS630 in Aeromonas salmonicida ranges from 8 to 35 and is much lower in other Aeromonas species. Conclusions HCN-IS630-RFLP is a powerful tool for subtyping of A. salmonicida. The high stability of IS630 insertions in A. salmonicida subsp. salmonicida indicates that it might have played a role in pathoadaptation of A. salmonicida which has reached an optimal configuration in the highly virulent and specific fish pathogen A. salmonicida subsp. salmonicida. PMID:23406017

  11. Serological comparison of selected isolates of Aeromonas salmonicida ssp. Salmonicida

    USGS Publications Warehouse

    Hahnel, G.B.; Gould, R.W.; Boatman, E.S.

    1983-01-01

    Eight isolates of Acronionus salmonicida ssp. salmonicida were collected during furunculosis epizootics in North American Pacific coast states and provinces. Both virulent and avirulent forms of each isolate, confirmed by challenge and electron microscopy, were examined. Serological comparisons by cross-absorption agglutination tests revealed no serological differences between isolates. Using the double diffusion precipitin test, a single band was observed when antigen from a sonicated virulent strain was reacted with antiserum against a sonicated, virulent strain absorbed with homologous, avirulent strain. The presence of the single band was eliminated by excess sonication.

  12. Analysis of a ferric uptake regulator (Fur) knockout mutant in Aeromonas salmonicida subsp. salmonicida.

    PubMed

    Ebanks, Roger O; Goguen, Michel; Knickle, Leah; Dacanay, Andrew; Leslie, Andrew; Ross, Neil W; Pinto, Devanand M

    2013-03-23

    Aeromonas salmonicida subsp. salmonicida is the etiological agent of furunculosis; a serious infectious disease in aquaculture raised salmonids. Iron acquisition has been shown to be critical for the survival of pathogenic bacteria during the course of infection. Previous work has demonstrated that A. salmonicida expresses iron-repressible IROMP proteins, suggesting the presence of iron acquisition systems that are under the control of a ferric uptake regulator (Fur). In this study, the A. salmonicida fur has been sequenced and a fur deletion strain generated. The A. salmonicida fur gene has an open reading frame of 428 bp, coding for a protein of 143 amino acids, and with high homology to previously described Fur proteins. The Fur protein product had a 94% sequence identity and 96% sequence similarity to the Aeromonas hydrophila Fur protein product. Transcription of the A. salmonicida fur gene was not regulated by the iron status of the bacterium and is not autoregulated, as in Escherichia coli. Proteomic analysis of the A. salmonicida fur mutant, fails to repress iron-regulated outer membrane proteins in the presence of iron. The A. salmonicida fur::KO mutant shows significantly reduced pathogenicity compared to the wild-type parental strain. In addition, the A. salmonicida fur mutant provides an important tool for further investigation of the iron acquisition mechanisms utilized by A. salmonicida.

  13. Aeromonas salmonicida grown in vivo.

    PubMed Central

    Garduño, R A; Thornton, J C; Kay, W W

    1993-01-01

    The virulent fish pathogen Aeromonas salmonicida was rapidly killed in vivo when restricted inside a diffusion chamber implanted intraperitoneally in rainbow trout. After a period of regrowth, the survivors had acquired resistance to host-mediated bacteriolysis, phagocytosis, and oxidative killing, properties which were subsequently lost by growth in vitro. Resistance to bacteriolysis and phagocytosis was associated with a newly acquired capsular layer revealed by acidic polysaccharide staining and electron microscopy. This capsular layer shielded the underlying, regular surface array (S-layer) from immunogold labeling with a primary antibody to the S-layer protein. Resistance to oxidative killing was mediated by a mechanism not associated with the presence of the capsular layer. An attenuated vaccine strain of A. salmonicida grown in vivo failed to express the capsular layer. Consequently, the in vivo-grown cells of this attenuated strain remained as sensitive to bacteriolysis, and as avidly adherent to macrophages, as the in vitro-grown cells. The importance of these new virulence determinants and their relation to the known virulence factors of A. salmonicida are discussed. Images PMID:8359906

  14. Development of a SYBR green I real-time PCR assay for specific identification of the fish pathogen Aeromonas salmonicida subspecies salmonicida.

    PubMed

    Fernández-Álvarez, Clara; González, Santiago F; Santos, Ysabel

    2016-12-01

    A SYBR Green I real-time polymerase chain reaction protocol for specific detection of the fish pathogen Aeromonas salmonicida subsp. salmonicida was developed and validated for rapid diagnosis of typical furunculosis. The sequence of the aopO gene of A. salmonicida subsp. salmonicida, which encodes for a serine/threonine protein kinase linked to virulence, was chosen for primer design. The selected primers amplified a 119-bp internal fragment of the aopO gene. The specificity test proved that 100 % (40/40) of the A. salmonicida subsp. salmonicida strains tested showed a positive amplification with subspecies-specific melting temperatures (Tm) of 80.75 ± 0.35 °C. Atypical A. salmonicida subspecies and other non-related bacterial fish pathogens did not amplify or showed unspecific melting profiles, except for one strain of A. salmonicida subsp. achromogenes and one strain of A. salmonicida subsp. smithia. The detection sensitivity was 21 fg of purified bacterial DNA per reaction, corresponding to 1-2 bacterial cells and 6-60 bacteria per reaction for seeded kidney and blood. The assay was highly reproducible with low variation coefficient values for intra-run and inter-run assays. The assay also allowed the specific detection of A. salmonicida subsp. salmonicida in tissues of fish naturally and experimentally infected. No amplification was detected when tissues from healthy fish or fish affected by other diseases were tested. The SYBR Green real-time PCR and melt curve analysis developed in this study is a rapid and accurate method for the specific identification of A. salmonicida subsp. salmonicida isolates and its detection on tissues of fish affected by furunculosis.

  15. Biological control of Aeromonas salmonicida subsp. salmonicida infection in rainbow trout (Oncorhynchus mykiss) using Aeromonas phage PAS-1.

    PubMed

    Kim, J H; Choresca, C H; Shin, S P; Han, J E; Jun, J W; Park, S C

    2015-02-01

    The potential control efficacy of Aeromonas phage PAS-1 was evaluated against Aeromonas salmonicida subsp. salmonicida infection in rainbow trout (Oncorhynchus mykiss) model in this study. The phage was co-cultured with the virulent A. salmonicida subsp. salmonicida strain AS05 that possesses the type III secretion system (TTSS) ascV gene, and efficient bacteriolytic activity was observed against the bacteria. The administration of PAS-1 in rainbow trout demonstrated that the phage was cleared from the fish within 200 h post-administration, and a temporal neutralizing activity against the phage was detected in the sera of phage-administrated fish. The administration of PAS-1 (multiplicity of infection: 10 000) in A. salmonicida subsp. salmonicida infected rainbow trout model showed notable protective effects, with increased survival rates and mean times to death. These results demonstrated that Aeromonas phage PAS-1 could be considered as an alternative biological control agent against A. salmonicida subsp. salmonicida infections in rainbow trout culture. © 2013 Blackwell Verlag GmbH.

  16. Aeromonas salmonicida resistance to complement-mediated killing.

    PubMed Central

    Merino, S; Albertí, S; Tomás, J M

    1994-01-01

    The resistance of Aeromonas salmonicida to complement-mediated killing was investigated by using different strains and their isogenic mutants that had been previously characterized for their surface components. We found that the classical complement pathway is involved in serum killing of susceptible A. salmonicida strains, while the alternative complement pathway seems not to be involved. All of the A. salmonicida strains are able to activate complement, but the smooth strains (with or without the A-layer) are resistant to complement-mediated killing. The reasons for this resistance are that C3b may be bound far from the cell membrane and that it is rapidly degraded; therefore, the lytic final complex C5b-9 (membrane attack complex) is not formed. Isogenic rough mutants are serum sensitive because they bind more C3b than the smooth strains, and if C3b is not completely degraded, then the lytic complex (C5b-9) is formed. Images PMID:7525485

  17. Triclosan Resistance in a Bacterial Fish Pathogen, Aeromonas salmonicida subsp. salmonicida, is Mediated by an Enoyl Reductase, FabV.

    PubMed

    Khan, Raees; Lee, Myung Hwan; Joo, Hae-Jin; Jung, Yong-Hoon; Ahmad, Shabir; Choi, Jin-Hee; Lee, Seon-Woo

    2015-04-01

    Triclosan, the widely used biocide, specifically targets enoyl-acyl carrier protein reductase (ENR) in the bacterial fatty acid synthesis system. Although the fish pathogen Aeromonas salmonicida subsp. salmonicida exhibits triclosan resistance, the nature of this resistance has not been elucidated. Here, we aimed to characterize the triclosan resistance of A. salmonicida subsp. salmonicida causing furunculosis. The fosmid library of triclosan-resistant A. salmonicida subsp. salmonicida was constructed to select a fosmid clone showing triclosan resistance. With the fosmid clone showing triclosan resistance, a subsequent secondary library search resulted in the selection of subclone pTSR-1. DNA sequence analysis of pTSR-1 revealed the presence of a chromosomal-borne fabV-encoding ENR homolog. The ENR of A. salmonicida (FabVas) exhibited significant homology with previously known FabV, including the catalytic domain YX(8)K. fabVas introduction into E. coli dramatically increased its resistance to triclosan. Heterologous expression of FabVas might functionally replace the triclosan-sensitive FabI in vivo to confer E. coli with triclosan resistance. A genome-wide search for fabVas homologs revealed the presence of an additional fabV gene (fabVas2) paralog in A. salmonicida strains and the fabVas orthologs from other gram-negative fish pathogens. Both of the potential FabV ENRs expressed similarly with or without triclosan supplement. This is the first report about the presence of two potential FabV ENRs in a single pathogenic bacterium. Our result suggests that triclosan-resistant ENRs are widely distributed in various bacteria in nature, and the wide use of this biocide can spread these triclosan-tolerant ENRs among fish pathogens and other pathogenic bacteria.

  18. The Aeromonas salmonicida Lipopolysaccharide Core from Different Subspecies: The Unusual subsp. pectinolytica.

    PubMed

    Merino, Susana; Tomás, Juan M

    2016-01-01

    Initial hydridization tests using Aeromonas salmonicida typical and atypical strains showed the possibility of different lipopolysaccharide (LPS) outer cores among these strains. By chemical structural analysis, LPS-core SDS-PAGE gel migration, and functional and comparative genomics we demonstrated that typical A. salmonicida (subsp. salmonicida) strains and atypical subsp. masoucida and probably smithia strains showed the same LPS outer core. A. salmonicida subsp. achromogenes strains show a similar LPS outer core but lack one of the most external residues (a galactose linked α1-6 to heptose), not affecting the O-antigen LPS linkage. A. salmonicida subsp. pectinolytica strains show a rather changed LPS outer core, which is identical to the LPS outer core from the majority of the A. hydrophila strains studied by genomic analyses. The LPS inner core in all tested A. salmonicida strains, typical and atypical, is well-conserved. Furthermore, the LPS inner core seems to be conserved in all the Aeromonas (psychrophilic or mesophilic) strains studied by genomic analyses.

  19. The mosaic architecture of Aeromonas salmonicida subsp. salmonicida pAsa4 plasmid and its consequences on antibiotic resistance

    PubMed Central

    Tanaka, Katherine H.; Vincent, Antony T.; Trudel, Mélanie V.; Paquet, Valérie E.; Frenette, Michel

    2016-01-01

    Aeromonas salmonicida subsp. salmonicida, the causative agent of furunculosis in salmonids, is an issue especially because many isolates of this bacterium display antibiotic resistances, which limit treatments against the disease. Recent results suggested the possible existence of alternative forms of pAsa4, a large plasmid found in A. salmonicida subsp. salmonicida and bearing multiple antibiotic resistance genes. The present study reveals the existence of two newly detected pAsa4 variants, pAsa4b and pAsa4c. We present the extensive characterization of the genomic architecture, the mobile genetic elements and the antimicrobial resistance genes of these plasmids in addition to the reference pAsa4 from the strain A449. The analysis showed differences between the three architectures with consequences on the content of resistance genes. The genomic plasticity of the three pAsa4 variants could be partially explained by the action of mobile genetic elements like insertion sequences. Eight additional isolates from Canada and Europe that bore similar antibiotic resistance patterns as pAsa4-bearing strains were genotyped and specific pAsa4 variants could be attributed to phenotypic profiles. pAsa4 and pAsa4c were found in Europe, while pAsa4b was found in Canada. In accordance with their content in conjugative transfer genes, only pAsa4b and pAsa4c can be transferred by conjugation in Escherichia coli. The plasticity of pAsa4 variants related to the acquisition of antibiotic resistance indicates that these plasmids may pose a threat in terms of the dissemination of antimicrobial-resistant A. salmonicida subsp. salmonicida bacteria. PMID:27812409

  20. Two Catechol Siderophores, Acinetobactin and Amonabactin, Are Simultaneously Produced by Aeromonas salmonicida subsp. salmonicida Sharing Part of the Biosynthetic Pathway.

    PubMed

    Balado, Miguel; Souto, Alba; Vences, Ana; Careaga, Valeria P; Valderrama, Katherine; Segade, Yuri; Rodríguez, Jaime; Osorio, Carlos R; Jiménez, Carlos; Lemos, Manuel L

    2015-12-18

    The iron uptake mechanisms based on siderophore synthesis used by the fish pathogen Aeromonas salmonicida subsp. salmonicida are still not completely understood, and the precise structure of the siderophore(s) is unknown. The analysis of genome sequences revealed that this bacterium possesses two gene clusters putatively involved in the synthesis of siderophores. One cluster is a candidate to encode the synthesis of acinetobactin, the siderophore of the human pathogen Acinetobacter baumannii, while the second cluster shows high similarity to the genes encoding amonabactin synthesis in Aeromonas hydrophila. Using a combination of genomic analysis, mutagenesis, biological assays, chemical purification, and structural determination procedures, here we demonstrate that most A. salmonicida subsp. salmonicida strains produce simultaneously the two siderophores, acinetobactin and amonabactin. Interestingly, the synthesis of both siderophores relies on a single copy of the genes encoding the synthesis of the catechol moiety (2,3-dihydroxybenzoic acid) and on one encoding a phosphopantetheinyl transferase. These genes are present only in the amonabactin cluster, and a single mutation in any of them abolishes production of both siderophores. We could also demonstrate that some strains, isolated from fish raised in seawater, produce only acinetobactin since they present a deletion in the amonabactin biosynthesis gene amoG. Our study represents the first evidence of simultaneous production of acinetobactin and amonabactin by a bacterial pathogen and reveals the plasticity of bacterial genomes and biosynthetic pathways. The fact that the same siderophore is produced by unrelated pathogens highlights the importance of these systems and their interchangeability between different bacteria.

  1. Occurrence and significance of atypical Aeromonas salmonicida in non-salmonid and salmonid fish species: a review.

    PubMed

    Wiklund, T; Dalsgaard, I

    1998-02-26

    Bacterial strains of Aeromonas salmonicida included in the recognized subsp. acromogenes, subsp. masoucida, and subsp. smithia in addition to the large number of strains not included in any of the described subspecies are referred to as atypical A. salmonicida. The atypical strains form a very heterogeneous group with respect to biochemical characteristics, growth conditions, and production of extracellular proteasess. Consequently, the present taxonomy of the species A. salmonicida is rather ambiguous. Atypical A. salmonicida has been isolated from a wide range of cultivated and wild fish species, non-salmonids as well as salmonids, inhabiting fresh water, brackish water and marine environments in northern and central Europe, South Africa, North America, Japan and Australia. In non-salmonid fish species, infections with atypical strains often manifest themselves as superficial skin ulcerations. The best known diseases associated with atypical A. salmonicida are carp Cyprinus carpio erythrodermatitis, goldfish Carassius auratus ulcer disease, and ulcer disease of flounder Platichthys flesus, but atypical strains are apparently involved in more disease outbreaks than previously suspected. Macroscopical and microscopical studies of ulcerated fish indicate internal organs are infrequently invaded by atypical A. salmonicida. This view is supported by the fact that atypical strains are irregularly isolated from visceral organs of ulcerated fish. High mortality caused by atypical A. salmonicida has been observed in populations of wild non-salmonids and farmed salmonids, although the association between the mortality in the wild fish stocks and atypical A. salmonicida has not always been properly assessed. In injection experiments the pathogenicity of the atypical strains examined showed large variation. An extacellular A-layer has been detected in different atypical strains, but virulence mechanisms different from those described for (typical) A. salmonicida subsp

  2. Polyphasic characterization of Aeromonas salmonicida isolates recovered from salmonid and non-salmonid fish

    USGS Publications Warehouse

    Diamanka, A.; Loch, T.P.; Cipriano, R.C.; Faisal, M.

    2013-01-01

    Michigan's fisheries rely primarily upon the hatchery propagation of salmonid fish for release in public waters. One limitation on the success of these efforts is the presence of bacterial pathogens, including Aeromonas salmonicida, the causative agent of furunculosis. This study was undertaken to determine the prevalence of A. salmonicida in Michigan fish, as well as to determine whether biochemical or gene sequence variability exists among Michigan isolates. A total of 2202 wild, feral and hatchery-propagated fish from Michigan were examined for the presence of A. salmonicida. The examined fish included Chinook salmon, Oncorhynchus tshawytscha (Walbaum), coho salmon, O. kisutcha (Walbaum), steelhead trout, O. mykiss (Walbaum), Atlantic salmon, Salmo salar L., brook trout, Salvelinus fontinalis (Mitchill), and yellow perch, Perca flavescens (Mitchill). Among these, 234 fish yielded a brown pigment-producing bacterium that was presumptively identified as A. salmonicida. Further phenotypic and phylogenetic analyses identified representative isolates as Aeromonas salmonicida subsp. salmonicida and revealed some genetic and biochemical variability. Logistic regression analyses showed that infection prevalence varied according to fish species/strain, year and gender, whereby Chinook salmon and females had the highest infection prevalence. Moreover, this pathogen was found in six fish species from eight sites, demonstrating its widespread nature within Michigan.

  3. Comparative genomics profiling of clinical isolates of Aeromonas salmonicida using DNA microarrays

    PubMed Central

    Nash, John HE; Findlay, Wendy A; Luebbert, Christian C; Mykytczuk, Oksana L; Foote, Simon J; Taboada, Eduardo N; Carrillo, Catherine D; Boyd, Jessica M; Colquhoun, Duncan J; Reith, Michael E; Brown, Laura L

    2006-01-01

    Background Aeromonas salmonicida has been isolated from numerous fish species and shows wide variation in virulence and pathogenicity. As part of a larger research program to identify virulence genes and candidates for vaccine development, a DNA microarray was constructed using a subset of 2024 genes from the draft genome sequence of A. salmonicida subsp. salmonicida strain A449. The microarray included genes encoding known virulence-associated factors in A. salmonicida and homologs of virulence genes of other pathogens. We used microarray-based comparative genomic hybridizations (M-CGH) to compare selected A. salmonicida sub-species and other Aeromonas species from different hosts and geographic locations. Results Results showed variable carriage of virulence-associated genes and generally increased variation in gene content across sub-species and species boundaries. The greatest variation was observed among genes associated with plasmids and transposons. There was little correlation between geographic region and degree of variation for all isolates tested. Conclusion We have used the M-CGH technique to identify subsets of conserved genes from amongst this set of A. salmonicida virulence genes for further investigation as potential vaccine candidates. Unlike other bacterial characterization methods that use a small number of gene or DNA-based functions, M-CGH examines thousands of genes and/or whole genomes and thus is a more comprehensive analytical tool for veterinary or even human health research. PMID:16522207

  4. Subunit vaccine candidates against Aeromonas salmonicida in rainbow trout Oncorhynchus mykiss

    PubMed Central

    Jørgensen, Louise von Gersdorff; Skov, Jakob; Chettri, Jiwan Kumar; Holm Mattsson, Andreas; Dalsgaard, Inger; Kania, Per Walter; Buchmann, Kurt

    2017-01-01

    Aeromonas salmonicida subsp. salmonicida is the etiological agent of furunculosis and a major fish health problem in salmonid aquaculture worldwide. Injection vaccination with commercial mineral oil-adjuvanted bacterin vaccines has been partly successful in preventing the disease but in Danish rainbow trout (Oncorhynchus mykiss, Walbaum) aquaculture furunculosis outbreaks still occur. In this study we tested the efficacy of experimental subunit vaccines against A. salmonicida infection in rainbow trout. We utilized in silico screening of the proteome of A. salmonicida subsp. salmonicida strain A449 and identified potential protective protein antigens that were tested by in vivo challenge trial. A total of 14 proteins were recombinantly expressed in Escherichia coli and prepared in 3 different subunit vaccine combinations to immunize 3 groups of rainbow trout by intraperitoneal (i.p.) injection. The fish were exposed to virulent A. salmonicida 7 weeks after immunization. To assess the efficacy of the subunit vaccines we evaluated the immune response in fish after immunization and challenge infection by measuring the antibody levels and monitoring the survival of fish in different groups. The survival of fish at 3 weeks after challenge infection showed that all 3 groups of fish immunized with 3 different protein combinations exhibited significantly lower mortalities (17–30%) compared to the control groups (48% and 56%). The ELISA results revealed significantly elevated antibody levels in fish against several protein antigens, which in some cases were positively correlated to the survival. PMID:28182704

  5. Insertion sequence AS5 (ISAS5) is involved in the genomic plasticity of Aeromonas salmonicida

    PubMed Central

    Trudel, Mélanie V.; Tanaka, Katherine H.; Filion, Geneviève; Daher, Rana K.; Frenette, Michel; Charette, Steve J.

    2013-01-01

    The genome of the fish pathogen Aeromonas salmonicida subsp salmonicida harbors a large number of insertion sequences (ISs), many of which are located on plasmids. In the present study, we analyzed the small plasmid profile of A. salmonicida strains to identify evidences of plasmid alterations. Ten out of 78 strains analyzed displayed an unconventional plasmid profile. However the HER1104 strain was unique, having a positive PCR signal for pAsal1 plasmid despite not carrying this plasmid. Instead, HER1104 was bearing a plasmid at higher molecular weight than pAsal1. We characterized this new larger plasmid, which we called pAsal1B since it is a derivative of pAsal1 containing one more complete IS (ISAS5) than the parental plasmid. An additional 96 bp relic of ISAS5 was also present in pAsal1B. These results propose that ISAS5 is another active mobile genetic element in A. salmonicida subsp salmonicida and provided further proof of the genomic plasticity of this bacterium. PMID:23956951

  6. Infection routes of Aeromonas salmonicida in rainbow trout monitored in vivo by real-time bioluminescence imaging.

    PubMed

    Bartkova, S; Kokotovic, B; Dalsgaard, I

    2017-01-01

    Recent development of imaging tools has facilitated studies of pathogen infections in vivo in real time. This trend can be exemplified by advances in bioluminescence imaging (BLI), an approach that helps to visualize dissemination of pathogens within the same animal over several time points. Here, we employ bacterial BLI for examining routes of entry and spread of Aeromonas salmonicida susbp. salmonicida in rainbow trout. A virulent Danish A. salmonicida strain was tagged with pAKgfplux1, a dual-labelled plasmid vector containing the mutated gfpmut3a gene from Aequorea victoria and the luxCDABE genes from the bacterium Photorhabdus luminescens. The resulting A. salmonicida transformant exhibited growth properties and virulence identical to the wild-type A. salmonicida, which made it suitable for an experimental infection, mimicking natural conditions. Fish were infected with pAKgfplux1 tagged A. salmonicida via immersion bath. Colonization and subsequent tissue dissemination was followed over a 24-h period using the IVIS spectrum imaging workstation. Results suggest the pathogen's colonization sites are the dorsal and pectoral fin and the gills, followed by a progression through the internal organs and an ensuing exit via the anal opening. This study provides a tool for visualizing colonization of A. salmonicida and other bacterial pathogens in fish.

  7. Assessment of bacterial biodetoxification of herbicide atrazine using Aliivibrio fischeri cytotoxicity assay with prolonged contact time.

    PubMed

    Háhn, Judit; Szoboszlay, Sándor; Tóth, Gergő; Kriszt, Balázs

    2017-07-01

    In our study, we determined and compared the atrazine-biodetoxification ability of 41 bacterial strains and 21 consortia created of those with over 50% degradation rate in pure cultures. Biodegradation capacity was measured with GC-MS. Detoxification was assessed based on the cytotoxic effect of end-products to Aliivibrio fischeri in chronic bioluminescence inhibition assay with 25 h contact time. Chronic A. fischeri assay adapted to a microplate, which is suitable for examine numerous residues simultaneously, also appeared to be significantly more sensitive to atrazine compared to the standard acute (30 min) test. Due to its sensitivity, the chronic assay could be a valuable tool to provide a more comprehensive view of the ecological risks of atrazine and other chemicals. Thirteen strains were able to degrade more than 50% of 50 ppm atrazine. Four of these belong to Rhodococcus aetherivorans, R. qingshengii, Serratia fonticola and Olivibacter oleidegradans which species' atrazine degrading ability has never been reported before. Four consortia degrading ability was more effective than that of the creating individual strains; moreover, their residues did not show cytotoxic effects to A. fischeri. However, in several cases, the degradation products of sole strains and consortia resulted in significant bioluminescence inhibition. Thus high biodegradation (>90%) does not certainly mean the reduction or cessation of toxicity highlighting the importance of the evaluation of biological effects of degradation residues to improve the efficiency and abate the ecological risks of bioremediation techniques.

  8. Aeromonas salmonicida subsp. salmonicida in the light of its type-three secretion system

    PubMed Central

    Vanden Bergh, Philippe; Frey, Joachim

    2014-01-01

    Aeromonas salmonicida subsp. salmonicida is an important pathogen in salmonid aquaculture and is responsible for the typical furunculosis. The type-three secretion system (T3SS) is a major virulence system. In this work, we review structure and function of this highly sophisticated nanosyringe in A. salmonicida. Based on the literature as well as personal experimental observations, we document the genetic (re)organization, expression regulation, anatomy, putative functional origin and roles in the infectious process of this T3SS. We propose a model of pathogenesis where A. salmonicida induces a temporary immunosuppression state in fish in order to acquire free access to host tissues. Finally, we highlight putative important therapeutic and vaccine strategies to prevent furunculosis of salmonid fish. PMID:24119189

  9. Involvement of LuxS in Aeromonas salmonicida metabolism, virulence and infection in Atlantic salmon (Salmo salar L).

    PubMed

    Meng, Lingjie; Du, Yishuai; Liu, Pengfei; Li, Xian; Liu, Ying

    2017-05-01

    Quorum sensing is a bacterial density dependent communication system, which regarded to regulate co-operative behaviors of community and mediated by extracellular signal molecules named autoinducers (AI). Among various signals, autoinducer-2 (AI-2) is believed to be the messengers inter species and produced by LuxS. For Aeromonas salmonicida (A. salmonicida), an opportunistic pathogen to many cold-water teleost, little information has been known about the function of AI-2 and LuxS. Therefore, our aim was to preliminarily clarify the function of LuxS in A. salmonicida. The consequences demonstrated that wild type A. salmonicida exhibited AI-2 activity and luxS defective mutant strain fail to produce AI-2 signals. Furthermore, it was suggested that luxS deficiency could impact bacterial morphology, surface properties and virulence dramatically. Challenge experiment showed a tendency that immune factors expressed earlier when Atlantic salmon was infected with ΔluxS strain. Overall, we hypothesis that AI-2 quorum sensing could regulate the expression of A-layer protein coding gene vapA, and then influence bacterial survival ability when suffered from attack of the host immune system. Though additional studies are warranted, our study will supply a new thinking to control the damage caused by A. salmonicida. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Design of a toxicity biosensor based on Aliivibrio fischeri entrapped in a disposable card.

    PubMed

    Jouanneau, Sulivan; Durand-Thouand, Marie-José; Thouand, Gérald

    2016-03-01

    The degradation of the marine environment is a subject of concern for the European authorities primarily because of its contamination by hydrocarbons. The traditional methods (ISO 11348 standard) of general toxicity assessment are unsuitable in a context of in situ monitoring, such as seaports or bathing zones. Consequently, to address this issue, bacterial biosensors appear to be pertinent tools. This article presents the design of an innovative bioluminescent biosensor dedicated to in situ toxicity monitoring. This biosensor is based on the entrapment of the wild marine bioluminescent bacterial strain Aliivibrio fischeri ATCC® 49387™ in an agarose matrix within a disposable card. A pre-study was needed to select the most biological parameters. In particular, the regenerating medium's composition and the hydrogel concentration needed for the bacterial entrapment (mechanical resistance) were optimized. Based on these data, the ability of the bacterial reporter to assess the sample toxicity was demonstrated using naphthalene as a chemical model. The biosensor's results show a lower sensitivity to naphthalene (EC50 = 95 mg/L) compared with the results obtained using the reference method (EC50 = 43 mg/L). With this architecture, the biosensor is an interesting compromise among low maintenance, ease of use, appropriate sensitivity, relatively low cost and the ability to control online toxicity.

  11. Hydrogenosomes in the diplomonad Spironucleus salmonicida

    PubMed Central

    Jerlström-Hultqvist, Jon; Einarsson, Elin; Xu, Feifei; Hjort, Karin; Ek, Bo; Steinhauf, Daniel; Hultenby, Kjell; Bergquist, Jonas; Andersson, Jan O.; Svärd, Staffan G.

    2013-01-01

    Acquisition of the mitochondrion is a key event in the evolution of the eukaryotic cell, but diversification of the organelle has occurred during eukaryotic evolution. One example of such mitochondria-related organelles (MROs) are hydrogenosomes, which produce ATP by substrate-level phosphorylation with hydrogen as a byproduct. The diplomonad parasite Giardia intestinalis harbours mitosomes, another type of MRO. Here we identify MROs in the salmon parasite Spironucleus salmonicida with similar protein import and Fe–S cluster assembly machineries as in Giardia mitosomes. We find that hydrogen production is prevalent in the diplomonad genus Spironucleus, and that S. salmonicida MROs contain enzymes characteristic of hydrogenosomes. Evolutionary analyses of known hydrogenosomal components indicate their presence in the diplomonad ancestor, and subsequent loss in Giardia. Our results suggest that hydrogenosomes are metabolic adaptations predating the split between parabasalids and diplomonads, which is deeper than the split between animals and fungi in the eukaryotic tree. PMID:24042146

  12. Interaction of the fish pathogen Aeromonas salmonicida with rainbow trout macrophages.

    PubMed Central

    Garduño, R A; Kay, W W

    1992-01-01

    A procedure was developed to culture rainbow trout macrophages (M phi) on supported glass coverslips. Using this method and a variety of well-characterized Aeromonas salmonicida strains with normal or altered cell surfaces, we investigated the role of this unusual bacterial surface in the bacterium-M phi interaction. An intact crystalline protein array, the A-layer, mediated adherence of A. salmonicida cells to M phi even in the absence of opsonins. In contrast, unopsonized cells of an A-layer-negative (A-) mutant with a smooth lipopolysaccharide (LPS) layer were unable to interact with M phi. However, this ability was recovered when the A-layer was reconstituted onto the smooth LPS surface of these A- LPS+ cells. Two A. salmonicida mutants possessing the A-layer in different disorganized states had a reduced ability to interact with M phi. A+ cells grown under calcium limitation produced A-layers locked into an alternative conformation which mediated the highest levels of M phi association in the absence of opsonins or any other surface coating. Coating A+ cells with hemin greatly increased their levels of M phi association, and bacterial cells grown on trout blood agar plates also had a dramatic increase in their ability to interact with M phi. Only A+ A. salmonicida cells were highly cytotoxic to trout M phi, especially after being coated with hemin, presumably due to a more focused targeting of the bacterial cell onto the M phi surface and/or into the intracellular regions of the M phi. Images PMID:1398975

  13. Screening microorganisms for insulin binding reveals binding by Burkholderia multivorans and Burkholderia cenocepacia and novel attachment of insulin to Aeromonas salmonicida via the A-layer.

    PubMed

    Nisr, Raid B; Moody, A John; Gilpin, Martyn L

    2012-03-01

    Exposure to microorganisms is considered an environmental factor that can contribute to Type 1 diabetes. Insulin-binding proteins (IBPs) on microorganisms may induce production of antibodies that can react with the human insulin receptor (HIR) with possible consequences in developing a diabetic autoimmune response against HIR and insulin. The interaction of insulin with microorganisms was studied by screening 45 microbial species for their ability to bind insulin. Binding assays were performed using labelled insulin to identify insulin-binding components on the microorganisms. Burkholderia multivorans and Burkholderia cenocepacia isolated from patients with cystic fibrosis (CF) and the fish pathogen Aeromonas salmonicida were the only strains of those tested, which showed insulin-binding components on their cell surfaces. Further work with A. salmonicida suggested that the insulin-binding activity of A. salmonicida is due to the A-layer. A mutant of A. salmonicida lacking the A-layer showed binding, but at a much reduced rate suggesting another insulin-binding component in addition to the high affinity of the A-protein. Soluble protein lysates were subjected to Western ligand blotting using peroxidase-labelled insulin to detect IBPs. Two positive IBPs were apparent at approximately 30 and 20 kDa in lysates from Burkholderia strains, but no IBP was detected in A. salmonicida lysates.

  14. Differential partition of virulent Aeromonas salmonicida and attenuated derivatives possessing specific cell surface alterations in polymer aqueous-phase systems

    NASA Technical Reports Server (NTRS)

    Van Alstine, J. M.; Trust, T. J.; Brooks, D. E.

    1986-01-01

    Two-polymer aqueous-phase systems in which partitioning of biological matter between the phases occurs according to surface properties such as hydrophobicity, charge, and lipid composition are used to compare the surface properties of strains of the fish pathogen Aeromonas salmonicida. The differential ability of strains to produce a surface protein array crucial to their virulence, the A layer, and to produce smooth lipopolysaccharide is found to be important in the partitioning behavior of Aeromonas salmonicida. The presence of the A layer is shown to decrease the surface hydrophilicity of the pathogen, and to increase specifically its surface affinity for fatty acid esters of polyethylene glycol. The method has application to the analysis of surface properties crucial to bacterial virulence, and to the selection of strains and mutants with specific surface characteristics.

  15. Haemorrhagic septicaemia by Aeromonas salmonicida subsp. salmonicida in a black-tip reef shark (Carcharhinus melanopterus).

    PubMed

    Briones, V; Fernández, A; Blanco, M; Ramiro, F; de Vicente, M L; García, J; Méndez, J L; Goyache, J

    1998-09-01

    One black-tip reef shark (Carcharhinus melanopterus) was found dead without previous signs of disease. Major lesions consisted in cutaneous erythema, mainly at the base of the fins, focal to diffuse inflammatory lesions in gills and intestinal wall, and discrete haemorrhages in the same organs, liver and kidneys. Microcolonies of Gram-negative rods were observed in the lamina propia of gills, underneath the intestinal mucosa and randomly distributed in the renal and hepatic parenchymas. Also, emboli containing Gram-negative rods were observed in capillaries of these organs. Aeromonas salmonicida subsp. salmonicida was isolated in pure culture from gills, liver and intestine. Specific immunostaining confirmed the relationship between the isolate and lesion-associated bacteria. No previous reports on this infection in sharks have been found in the literature.

  16. A Novel lux Operon in the Cryptically Bioluminescent Fish Pathogen Vibrio salmonicida Is Associated with Virulence▿

    PubMed Central

    Nelson, Eric J.; Tunsjø, Hege S.; Fidopiastis, Pat M.; Sørum, Henning; Ruby, Edward G.

    2007-01-01

    The cold-water-fish pathogen Vibrio salmonicida expresses a functional bacterial luciferase but produces insufficient levels of its aliphatic-aldehyde substrate to be detectably luminous in culture. Our goals were to (i) better explain this cryptic bioluminescence phenotype through molecular characterization of the lux operon and (ii) test whether the bioluminescence gene cluster is associated with virulence. Cloning and sequencing of the V. salmonicida lux operon revealed that homologs of all of the genes required for luminescence are present: luxAB (luciferase) and luxCDE (aliphatic-aldehyde synthesis). The arrangement and sequence of these structural lux genes are conserved compared to those in related species of luminous bacteria. However, V. salmonicida strains have a novel arrangement and number of homologs of the luxR and luxI quorum-sensing regulatory genes. Reverse transcriptase PCR analysis suggests that this novel arrangement of quorum-sensing genes generates antisense transcripts that may be responsible for the reduced production of bioluminescence. In addition, infection with a strain in which the luxA gene was mutated resulted in a marked delay in mortality among Atlantic salmon relative to infection with the wild-type parent in single-strain challenge experiments. In mixed-strain competition between the luxA mutant and the wild type, the mutant was attenuated up to 50-fold. It remains unclear whether the attenuation results from a direct loss of luciferase or a polar disturbance elsewhere in the lux operon. Nevertheless, these findings document for the first time an association between a mutation in a structural lux gene and virulence, as well as provide a new molecular system to study Vibrio pathogenesis in a natural host. PMID:17277225

  17. The impact of Aeromonas salmonicida infection on innate immune parameters of Atlantic salmon (Salmo salar L).

    PubMed

    Du, Yishuai; Yi, Mengmeng; Xiao, Peng; Meng, Lingjie; Li, Xian; Sun, Guoxiang; Liu, Ying

    2015-05-01

    Enzyme activities and gene expression of a number of innate immune parameters in the serum, mucus and skin of Atlantic salmon (Salmo salar) were investigated after challenge with a pathogenic strain of Aeromonas salmonicida (A. salmonicida). Fish were injected in the dorsal muscle with either 100 μl bacterium solution, about 3.05 × 10(7) CFU/ml A. salmonicida, or 100 μl 0.9% NaCl (as control group) and tissue samples were collected at days 0, 2, 4 and 6 post-injection. Lysozyme (LSZ) and alkaline phosphatase (AKP) activities in serum, mucus and skin, and LSZ and AKP mRNA expression in skin of the challenged fish were higher than those of the control at most of the experimental time, with significant differences at several time points (P < 0.05), indicating the involvement of LSZ and AKP in the innate immunity of Atlantic salmon to A. salmonicida. Superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities in mucus and skin, along with the SOD, POD and CAT mRNA expression in skin significantly decreased at day 4 and 6, indicating the decreased antioxidant capacity of the challenged fish. Glutamate pyruvate transaminase (GPT) and glutamic oxalacetic transaminase (GOT) activities in serum, mucus and skin of the challenged group were all higher than those of the control after the injection, and at several time points significant differences were found between the two groups, suggesting organs of fish were impaired after the pathogen infection. The changes of the GPT and GOT activities could be used as potential biomarkers for the impairment of physiological functions caused by the pathogen infection. Identified biomarkers of the immune responses will contribute to the early-warning system of the disease. So this study will not only provide a theoretical basis for vaccine development, but also provide basic data for the establishment of early warning systems for diseases caused by A. salmonicida in Atlantic salmon rearing. Copyright © 2015 Elsevier

  18. The protective effect of humic-rich substances on atypical Aeromonas salmonicida subsp. salmonicida infection in common carp (Cyprinus carpio L.).

    PubMed

    Yamin, G; Falk, R; Avtalion, R R; Shoshana, N; Ofek, T; Smirnov, R; Rubenstein, G; van Rijn, J

    2017-05-11

    When challenged with atypical Aeromonas salmonicida subsp. salmonicida, exposure of the common carp (Cyprinus carpio L.) to different humic-rich compounds resulted in a significant reduction in infection rates. Specifically, in fish exposed to (i) humic-rich water and sludge from a recirculating system, (ii) a synthetic humic acid, and (iii) a Leonardite-derived humic-rich extract, infection rates were reduced to 14.9%, 17.0% and 18.8%, respectively, as compared to a 46.8% infection rate in the control treatment. An additional set of experiments was performed to examine the effect of humic-rich components on the growth of the bacterial pathogen. Liquid culture medium supplemented with either humic-rich water from the recirculating system, the synthetic humic acid or the Leonardite humic-rich extract resulted in a growth reduction of 41.1%, 45.2% and 61.6%, respectively, as compared to the growth of the Aeromonas strain in medium devoid of humic substances. Finally, in a third set of experiments it was found that while the innate immune system of the carps was not affected by their exposure to humic-rich substances, their acquired immune system was affected. Fish, immunized against bovine serum albumin, displayed elevated antibody titres as compared to immunized carps which were not exposed to the various sources of humic substances. © 2017 John Wiley & Sons Ltd.

  19. Transcriptomic and proteomic analyses of splenic immune mechanisms of rainbow trout (Oncorhynchus mykiss) infected by Aeromonas salmonicida subsp. salmonicida.

    PubMed

    Long, Meng; Zhao, Juan; Li, Tongtong; Tafalla, Carolina; Zhang, Qianqian; Wang, Xiehao; Gong, Xiaoning; Shen, Zhixin; Li, Aihua

    2015-06-03

    Furunculosis caused by Aeromonas salmonicida subsp. salmonicida is an epidemic disease among salmonids, including rainbow trout (Oncorhynchus mykiss). However, the immune mechanisms that are elicited in rainbow trout against the invasion of A. salmonicida are not yet fully understood. In this study, we examined the spleen to investigate the immune response of rainbow trout at 3days post-infection by A. salmonicida at the transcriptome and proteome levels by using Illumina-seq and iTRAQ methods, respectively. A total of 1036 genes and 133 proteins were found to undergo differential expression during the immune response of the spleen against A. salmonicida infection. Gene ontology and KEGG analysis were conducted among the differentially expressed genes and proteins, revealing that immune system process and response to stimulus were the top two biological processes, and immune system, signaling molecules and interaction, and immune diseases were the differential pathways activated. Correlation analysis of transcriptomic and proteomic results showed 17 proteins (11 upregulated and 6 downregulated) having consistent expression at RNA and protein levels. Moreover, protein-protein interaction analysis showed that diseases, proteasome, aminoacyl-tRNA biosynthesis, and nucleotide metabolism were the main interactions among the consistently expressed proteins. Consequently, these upregulated proteins, namely, ferritin, CD209, IL13Rα1, VDAC2, GIMAP7, PSMA1, and two ANXA11s could be considered as potential biomarkers for rainbow trout immune responses. This study provides the first identification of immune markers through an analysis of the differential expression of both genes and their corresponding protein products in the spleen of rainbow trout after infection by A. salmonicida, shedding light on the molecular mechanisms triggered in rainbow trout against A. salmonicida infection and providing new molecular targets for further immunological research in fish. Copyright

  20. Integron-containing IncU R plasmids pRAS1 and pAr-32 from the fish pathogen Aeromonas salmonicida.

    PubMed

    Sørum, Henning; L'Abée-Lund, Trine M; Solberg, Asta; Wold, Anette

    2003-04-01

    A 45-kb R plasmid, pRAS1, that confers resistance to tetracyclines, trimethoprim, and sulfonamides was isolated in 1989 from an atypical strain of the fish pathogen Aeromonas salmonicida. This plasmid could be transferred by conjugation to Escherichia coli with a high degree of efficiency (frequency, 0.48). The following year pRAS1 was isolated from A. salmonicida subsp. salmonicida in the same area. Incompatibility group U plasmid pRAS1 contained a drug resistance-determining region of 12 kb consisting of a class 1 integron similar to In4 of Tn1696 but with a dfrA16 gene cassette inserted. Close to IS6100 at the right end of Tn4 was a truncated Tn1721. Restriction enzyme analysis showed that R plasmid pAr-32, isolated from A. salmonicida in Japan in 1970, had the same backbone structure as pRAS1, while the drug resistance-determining region contained a complex class 1 integron with an aadA2 cassette; the chloramphenicol resistance gene catA2, as in In6 of pSa; and a duplicate of the 3' conserved segment of the integron.

  1. The Aeromonas salmonicida subsp. salmonicida exoproteome: determination of the complete repertoire of Type-Three Secretion System effectors and identification of other virulence factors.

    PubMed

    Vanden Bergh, Philippe; Heller, Manfred; Braga-Lagache, Sophie; Frey, Joachim

    2013-09-27

    Aeromonas salmonicida subsp. salmonicida, the etiologic agent of furunculosis, is a major pathogen of fisheries worldwide. Several virulence factors have been described, but the type-three secretion system (T3SS) is recognized as having a major effect on virulence by injecting effectors directly into fish cells. In this study we used high-throughput proteomics to display the differences between in vitro secretome of A. salmonicida wild-type (wt, hypervirulent, JF2267) and T3SS-deficient (isogenic ΔascV, extremely low-virulent, JF2747) strains in exponential and stationary phases of growth. Results confirmed the secretion of effectors AopH, AexT, AopP and AopO via T3SS, and for the first time demonstrated the impact of T3SS in secretion of Ati2, AopN and ExsE that are known as effectors in other pathogens. Translocators, needle subunits, Ati1, and AscX were also secreted in supernatants (SNs) dependent on T3SS. AopH, Ati2, AexT, AopB and AopD were in the top seven most abundant excreted proteins. EF-G, EF-Tu, DnaK, HtpG, PNPase, PepN and MdeA were moderately secreted in wt SNs and predicted to be putative T3 effectors by bioinformatics. Pta and ASA_P5G088 were increased in wt SNs and T3-associated in other bacteria. Ten conserved cytoplasmic proteins were more abundant in wt SNs than in the ΔascV mutant, but without any clear association to a secretion system. T1-secreted proteins were predominantly found in wt SNs: OmpAI, OmpK40, DegQ, insulinase ASA_0716, hypothetical ASA_0852 and ASA_3619. Presence of T3SS components in pellets was clearly decreased by ascV deletion, while no impact was observed on T1- and T2SS. Our results demonstrated that the ΔascV mutant strain excreted well-described (VapA, AerA, AerB, GCAT, Pla1, PlaC, TagA, Ahe2, GbpA and enolase) and yet uncharacterized potential toxins, adhesins and enzymes as much as or even more than the wt strain. Other putative important virulence factors were not detected. We demonstrated the whole in vitro

  2. The Aeromonas salmonicida subsp. salmonicida exoproteome: determination of the complete repertoire of Type-Three Secretion System effectors and identification of other virulence factors

    PubMed Central

    2013-01-01

    Background Aeromonas salmonicida subsp. salmonicida, the etiologic agent of furunculosis, is a major pathogen of fisheries worldwide. Several virulence factors have been described, but the type-three secretion system (T3SS) is recognized as having a major effect on virulence by injecting effectors directly into fish cells. In this study we used high-throughput proteomics to display the differences between in vitro secretome of A. salmonicida wild-type (wt, hypervirulent, JF2267) and T3SS-deficient (isogenic ΔascV, extremely low-virulent, JF2747) strains in exponential and stationary phases of growth. Results Results confirmed the secretion of effectors AopH, AexT, AopP and AopO via T3SS, and for the first time demonstrated the impact of T3SS in secretion of Ati2, AopN and ExsE that are known as effectors in other pathogens. Translocators, needle subunits, Ati1, and AscX were also secreted in supernatants (SNs) dependent on T3SS. AopH, Ati2, AexT, AopB and AopD were in the top seven most abundant excreted proteins. EF-G, EF-Tu, DnaK, HtpG, PNPase, PepN and MdeA were moderately secreted in wt SNs and predicted to be putative T3 effectors by bioinformatics. Pta and ASA_P5G088 were increased in wt SNs and T3-associated in other bacteria. Ten conserved cytoplasmic proteins were more abundant in wt SNs than in the ΔascV mutant, but without any clear association to a secretion system. T1-secreted proteins were predominantly found in wt SNs: OmpAI, OmpK40, DegQ, insulinase ASA_0716, hypothetical ASA_0852 and ASA_3619. Presence of T3SS components in pellets was clearly decreased by ascV deletion, while no impact was observed on T1- and T2SS. Our results demonstrated that the ΔascV mutant strain excreted well-described (VapA, AerA, AerB, GCAT, Pla1, PlaC, TagA, Ahe2, GbpA and enolase) and yet uncharacterized potential toxins, adhesins and enzymes as much as or even more than the wt strain. Other putative important virulence factors were not detected. Conclusions We

  3. Diversity and Homogeneity among Small Plasmids of Aeromonas salmonicida subsp. salmonicida Linked with Geographical Origin

    PubMed Central

    Attéré, Sabrina A.; Vincent, Antony T.; Trudel, Mélanie V.; Chanut, Romain; Charette, Steve J.

    2015-01-01

    Furunculosis, which is caused by Aeromonas salmonicida subsp. salmonicida, is a major salmonid disease in fish farms worldwide. Several plasmids found in this bacterium confer phenotypes such drug resistance and virulence. Small plasmids (pAsa1, pAsa2, pAsa3, and pAsal1) related to ColE1- and ColE2-type replicons are usually present in its normal plasmidome. In the present study, with the objective to investigate if these plasmids display particularities related to the origin of the isolates bearing them, a total of 153 isolates, including 78 new and 75 previously described, were analyzed for the presence of small plasmids by PCR and DNA restriction fragment profiling. A geographical dichotomy between Canadian and European isolates for their propensity to do not have pAsa3 or pAsal1 was found. In addition, the genotyping analysis led to the identification of two European isolates harboring an unusual pAsal1. An investigation by next-generation sequencing (NGS) of these two isolates shed light on two pAsal1 variants (pAsal1C and pAsal1D). As with pAsal1B, another pAsal1 variant previously described, these two new variants bore a second insertion sequence (ISAS5) in addition to the usual ISAS11. The characterization of these variants suggested that they could predominate over the wild-type pAsal1 in stressful conditions such as growth at temperatures of 25°C and above. To obtain a comprehensive portrait of the mutational pressure on small plasmids, 26 isolates whose DNA had been sequenced by NGS were investigated. pAsa3 and pAsal1 were more prone to mutations than pAsa1 and pAsa2, especially in the mobA gene, which encodes a relaxase and a primase. Lastly, the average copy number of each plasmid per cell was assessed using raw sequencing data. A clear trend with respect to the relative proportion per cell of each plasmid was identified. Our large-scale study revealed a geographical dichotomy in small plasmid repertoire in addition to a clear trend for pAsa3 and p

  4. Effects of temperature on biochemical reactions and drug resistance of virulent and avirulent Aeromonas salmonicida

    USGS Publications Warehouse

    Hahnel, G.B.; Gould, R.W.

    1982-01-01

    Incubation temperatures of 11°, 18° and 28° did not substantially affect biochemical reactions of either virulent or avirulent forms of Aeromonas salmonicida subspecies salmonicida. The only change observed, amygdalin fermentation, was positive at 11° and 18° but negative at 28°C. Several isolates utilized sucrose, a characteristic not normally recognized for A. salmonicida subspecies salmonicida.Antimicrobial susceptibility screening indicated resistance to novobiocin increased at the higher incubation temperatures. Standardized drug sensitivity testing procedures and precise zone diameter interpretive standards for bacterial fish pathogens are needed.

  5. QTL detection for Aeromonas salmonicida resistance related traits in turbot (Scophthalmus maximus)

    PubMed Central

    2011-01-01

    Background Interactions between fish and pathogens, that may be harmless under natural conditions, often result in serious diseases in aquaculture systems. This is especially important due to the fact that the strains used in aquaculture are derived from wild strains that may not have had enough time to adapt to new disease pressures. The turbot is one of the most promising European aquaculture species. Furunculosis, caused by the bacterium Aeromonas salmonicida, produces important losses to turbot industry. An appealing solution is to achieve more robust broodstock, which can prevent or diminish the devastating effects of epizooties. Genomics strategies have been developed in turbot to look for candidate genes for resistance to furunculosis and a genetic map with appropriate density to screen for genomic associations has been also constructed. In the present study, a genome scan for QTL affecting resistance and survival to A. salmonicida in four turbot families was carried out. The objectives were to identify consistent QTL using different statistical approaches (linear regression and maximum likelihood) and to locate the tightest associated markers for their application in genetic breeding strategies. Results Significant QTL for resistance were identified by the linear regression method in three linkage groups (LGs 4, 6 and 9) and for survival in two LGs (6 and 9). The maximum likelihood methodology identified QTL in three LGs (5, 6 and 9) for both traits. Significant association between disease traits and genotypes was detected for several markers, some of them explaining up to 17% of the phenotypic variance. We also identified candidate genes located in the detected QTL using data from previously mapped markers. Conclusions Several regions controlling resistance to A. salmonicida in turbot have been detected. The observed concordance between different statistical methods at particular linkage groups gives consistency to our results. The detected associated

  6. Synthesis, characterization and toxicological evaluation of Cr₂O₃ nanoparticles using Daphnia magna and Aliivibrio fischeri.

    PubMed

    Puerari, Rodrigo Costa; da Costa, Cristina H; Vicentini, Denice S; Fuzinatto, Cristiane F; Melegari, Silvia P; Schmidt, Éder C; Bouzon, Zenilda L; Matias, William G

    2016-06-01

    Chromium III oxide (Cr2O3) nanoparticles (NPs) are used in pigments for ceramics, dyes, paints and cosmetics. However, few studies addressing the toxic potential of these NPs have been reported in the literature. Thus, this research aimed to evaluate the acute and chronic effects of Cr2O3 NPs through acute toxicity tests with Daphnia magna and Aliivibrio fischeri and chronic toxicity tests with Daphnia magna. Cr2O3 NPs were synthesized by the sol-gel method and characterized through TEM, X-Ray diffraction (XRD), zeta potential (ZP) and surface area analysis. In the acute toxicity tests the EC(50,48h) value obtained with D. magna was 6.79 mg L(-1) and for A. fischeri the EC(50,15min) value was 16.10 mg L(-1) and the EC(50,30min) value was 12.91 mg L(-1). Regarding the chronic toxicity tests with D. magna, effects on longevity (OEC=1.00 mg L(-1)), reproduction (OEC=1.00 mg L(-1)) and growth (OEC=0.50 mg L(-1)) were observed. On the SEM and TEM images, ultrastructural alterations in the organelles of exposed organisms were also observed. Thus, toxicological studies with NPs are of great importance in order to reduce the risk of environmental contamination.

  7. Diversity of antibiotic-resistance genes in Canadian isolates of Aeromonas salmonicida subsp. salmonicida: dominance of pSN254b and discovery of pAsa8

    PubMed Central

    Trudel, Mélanie V.; Vincent, Antony T.; Attéré, Sabrina A.; Labbé, Myriam; Derome, Nicolas; Culley, Alexander I.; Charette, Steve J.

    2016-01-01

    The bacterium Aeromonas salmonicida subsp. salmonicida is a common pathogen in fish farms worldwide. Since the antibiotic resistance of this bacterial species is on the increase, it is important to have a broader view on this issue. In the present study, we tested the presence of known plasmids conferring multi-drug resistance as well as antibiotic resistance genes by a PCR approach in 100 Canadian A. salmonicida subsp. salmonicida isolates. Our study highlighted the dominance of the conjugative pSN254b plasmid, which confers multi-drug resistance. We also identified a new multi-drug plasmid named pAsa8, which has been characterized by a combination of sequencing technologies (Illumina and Oxford nanopore). This new plasmid harbors a complex class 1 integron similar to the one of the Salmonella genomic island 1 (SGI1) found in Salmonella enterica and Proteus mirabilis. Consequently, in addition to providing an update on the A. salmonicida subsp. salmonicida isolates that are resistant to antibiotics, our data suggest that this bacterium is potentially an important reservoir of drug resistance genes and should consequently be monitored more extensively. In addition, we describe a screening method that has the potential to become a diagnostic tool that is complementary to other methods currently in use. PMID:27752114

  8. Detection of Variants of the pRAS3, pAB5S9, and pSN254 Plasmids in Aeromonas salmonicida subsp. salmonicida: Multidrug Resistance, Interspecies Exchanges, and Plasmid Reshaping

    PubMed Central

    Vincent, Antony T.; Trudel, Mélanie V.; Paquet, Valérie E.; Boyle, Brian; Tanaka, Katherine H.; Dallaire-Dufresne, Stéphanie; Daher, Rana K.; Frenette, Michel; Derome, Nicolas

    2014-01-01

    The ubiquitous water-borne Gram-negative bacterium Aeromonas salmonicida subsp. salmonicida is the causative agent of furunculosis, a worldwide disease in fish farms. Plasmids carrying antibiotic resistance genes have already been described for this bacterium. The aim of the present study was to identify and characterize additional multidrug resistance plasmids in A. salmonicida subsp. salmonicida. We sequenced the plasmids present in two multiple antibiotic-resistant isolates using high-throughput technologies. We also investigated 19 other isolates with various multidrug resistance profiles by genotyping PCR and assessed their resistance to tetracycline. We identified variants of the pAB5S9 and pSN254 plasmids that carry several antibiotic resistance genes and that have been previously reported in bacteria other than A. salmonicida subsp. salmonicida, which suggests a high level of interspecies exchange. Genotyping analyses and the antibiotic resistance profiles of the 19 other isolates support the idea that multiple versions of pAB5S9 and pSN254 exist in A. salmonicida subsp. salmonicida. We also identified variants of the pRAS3 plasmid. The present study revealed that A. salmonicida subsp. salmonicida harbors a wide variety of plasmids, which suggests that this ubiquitous bacterium may contribute to the spread of antibiotic resistance genes in the environment. PMID:25267667

  9. The impact of quorum sensing on the virulence of Aeromonas hydrophila and Aeromonas salmonicida towards burbot (Lota lota L.) larvae.

    PubMed

    Natrah, F M I; Alam, Md Iftakharul; Pawar, Sushant; Harzevili, A Shiri; Nevejan, Nancy; Boon, Nico; Sorgeloos, Patrick; Bossier, Peter; Defoirdt, Tom

    2012-09-14

    In this study, the link between quorum sensing in Aeromonas spp. and its virulence towards burbot (Lota lota) was investigated. High mortality occurred in burbot juveniles challenged with Aeromonas salmonicida HN-00, but not in juveniles challenged with Aeromonas hydrophila AH-1N. Meanwhile, both A. hydrophila AH-1N and A. salmonicida HN-00 were virulent towards larvae. The effect of quorum sensing on the virulence of A. hydrophila AH-1N towards burbot larvae was further investigated using quorum sensing mutants (N-(butyryl)-L-homoserine lactone production and receptor mutants). Challenge with these mutants resulted in higher survival of burbot larvae when compared to challenge with the wild type, and the addition of the signal molecule N-butyryl-L-homoserine lactone restored the virulence of the quorum sensing production mutant. Moreover, quorum sensing inhibitors protected the burbot larvae from both Aeromonas strains. Finally, the freshwater micro-algae Chlorella saccharophila and Chlamydomonas reinhardtii, which are able to interfere with quorum sensing, also protected burbot from the pathogens. However, QS interference was unlikely to be the only mechanism. This study revealed that the virulence of Aeromonas spp. towards burbot is regulated by quorum sensing and that quorum sensing inhibitors and micro-algae are promising biocontrol agents.

  10. Microencapsulated Aliivibrio fischeri in alginate microspheres for monitoring heavy metal toxicity in environmental waters.

    PubMed

    Futra, Dedi; Heng, Lee Yook; Surif, Salmijah; Ahmad, Asmat; Ling, Tan Ling

    2014-12-05

    In this article a luminescence fiber optic biosensor for the microdetection of heavy metal toxicity in waters based on the marine bacterium Aliivibrio fischeri (A. fischeri) encapsulated in alginate microspheres is described. Cu(II), Cd(II), Pb(II), Zn(II), Cr(VI), Co(II), Ni(II), Ag(I) and Fe(II) were selected as sample toxic heavy metal ions for evaluation of the performance of this toxicity microbiosensor. The loss of bioluminescence response from immobilized A. fischeri bacterial cells corresponds to changes in the toxicity levels. The inhibition of the luminescent biosensor response collected at excitation and emission wavelengths of 287 ± 2 nm and 487 ± 2 nm, respectively, was found to be reproducible and repeatable within the relative standard deviation (RSD) range of 2.4-5.7% (n = 8). The toxicity biosensor based on alginate micropsheres exhibited a lower limit of detection (LOD) for Cu(II) (6.40 μg/L), Cd(II) (1.56 μg/L), Pb(II) (47 μg/L), Ag(I) (18 μg/L) than Zn(II) (320 μg/L), Cr(VI) (1,000 μg/L), Co(II) (1700 μg/L), Ni(II) (2800 μg/L), and Fe(III) (3100 μg/L). Such LOD values are lower when compared with other previous reported whole cell toxicity biosensors using agar gel, agarose gel and cellulose membrane biomatrices used for the immobilization of bacterial cells. The A. fischeri bacteria microencapsulated in alginate biopolymer could maintain their metabolic activity for a prolonged period of up to six weeks without any noticeable changes in the bioluminescence response. The bioluminescent biosensor could also be used for the determination of antagonistic toxicity levels for toxicant mixtures. A comparison of the results obtained by atomic absorption spectroscopy (AAS) and using the proposed luminescent A. fischeri-based biosensor suggests that the optical toxicity biosensor can be used for quantitative microdetermination of heavy metal toxicity in environmental water samples.

  11. Microencapsulated Aliivibrio fischeri in Alginate Microspheres for Monitoring Heavy Metal Toxicity in Environmental Waters

    PubMed Central

    Futra, Dedi; Heng, Lee Yook; Surif, Salmijah; Ahmad, Asmat; Ling, Tan Ling

    2014-01-01

    In this article a luminescence fiber optic biosensor for the microdetection of heavy metal toxicity in waters based on the marine bacterium Aliivibrio fischeri (A. fischeri) encapsulated in alginate microspheres is described. Cu(II), Cd(II), Pb(II), Zn(II), Cr(VI), Co(II), Ni(II), Ag(I) and Fe(II) were selected as sample toxic heavy metal ions for evaluation of the performance of this toxicity microbiosensor. The loss of bioluminescence response from immobilized A. fischeri bacterial cells corresponds to changes in the toxicity levels. The inhibition of the luminescent biosensor response collected at excitation and emission wavelengths of 287 ± 2 nm and 487 ± 2 nm, respectively, was found to be reproducible and repeatable within the relative standard deviation (RSD) range of 2.4–5.7% (n = 8). The toxicity biosensor based on alginate micropsheres exhibited a lower limit of detection (LOD) for Cu(II) (6.40 μg/L), Cd(II) (1.56 μg/L), Pb(II) (47 μg/L), Ag(I) (18 μg/L) than Zn(II) (320 μg/L), Cr(VI) (1,000 μg/L), Co(II) (1700 μg/L), Ni(II) (2800 μg/L), and Fe(III) (3100 μg/L). Such LOD values are lower when compared with other previous reported whole cell toxicity biosensors using agar gel, agarose gel and cellulose membrane biomatrices used for the immobilization of bacterial cells. The A. fischeri bacteria microencapsulated in alginate biopolymer could maintain their metabolic activity for a prolonged period of up to six weeks without any noticeable changes in the bioluminescence response. The bioluminescent biosensor could also be used for the determination of antagonistic toxicity levels for toxicant mixtures. A comparison of the results obtained by atomic absorption spectroscopy (AAS) and using the proposed luminescent A. fischeri-based biosensor suggests that the optical toxicity biosensor can be used for quantitative microdetermination of heavy metal toxicity in environmental water samples. PMID:25490588

  12. The Genome of Spironucleus salmonicida Highlights a Fish Pathogen Adapted to Fluctuating Environments

    PubMed Central

    Xu, Feifei; Jerlström-Hultqvist, Jon; Einarsson, Elin; Ástvaldsson, Ásgeir; Svärd, Staffan G.; Andersson, Jan O.

    2014-01-01

    Spironucleus salmonicida causes systemic infections in salmonid fish. It belongs to the group diplomonads, binucleated heterotrophic flagellates adapted to micro-aerobic environments. Recently we identified energy-producing hydrogenosomes in S. salmonicida. Here we present a genome analysis of the fish parasite with a focus on the comparison to the more studied diplomonad Giardia intestinalis. We annotated 8067 protein coding genes in the ∼12.9 Mbp S. salmonicida genome. Unlike G. intestinalis, promoter-like motifs were found upstream of genes which are correlated with gene expression, suggesting a more elaborate transcriptional regulation. S. salmonicida can utilise more carbohydrates as energy sources, has an extended amino acid and sulfur metabolism, and more enzymes involved in scavenging of reactive oxygen species compared to G. intestinalis. Both genomes have large families of cysteine-rich membrane proteins. A cluster analysis indicated large divergence of these families in the two diplomonads. Nevertheless, one of S. salmonicida cysteine-rich proteins was localised to the plasma membrane similar to G. intestinalis variant-surface proteins. We identified S. salmonicida homologs to cyst wall proteins and showed that one of these is functional when expressed in Giardia. This suggests that the fish parasite is transmitted as a cyst between hosts. The extended metabolic repertoire and more extensive gene regulation compared to G. intestinalis suggest that the fish parasite is more adapted to cope with environmental fluctuations. Our genome analyses indicate that S. salmonicida is a well-adapted pathogen that can colonize different sites in the host. PMID:24516394

  13. Immunohistochemical study of inducible nitric oxide synthase and tumour necrosis factor alpha response in turbot (Scophthalmus maximus) experimentally infected with Aeromonas salmonicida subsp. salmonicida.

    PubMed

    Coscelli, Germán; Bermúdez, Roberto; Ronza, Paolo; Losada, Ana Paula; Quiroga, María Isabel

    2016-09-01

    Aeromonas salmonicida subsp. salmonicida represents one of the major threats in aquaculture, especially in salmonid fish and turbot farming. In order to fight bacterial infections, fish have an immune system composed by innate and specific cellular and humoral elements analogous to those present in mammals. However, innate immunity plays a primordial role against bacterial infections in teleost fish. Among these non-specific mechanisms, the production of nitric oxide (NO) by inducible nitric oxide synthase (iNOS) pathway and the tumour necrosis factor-alpha (TNFα) produced by mononuclear phagocytes, are two of the main immune effectors to eliminate bacterial pathogens. In this study, the distribution and kinetic of iNOS and TNFα-producing cells of kidney and spleen of turbot experimentally inoculated with A. salmonicida was assessed by immunohistochemistry. In control and challenged fish, individual iNOS(+) and TNFα(+) cells, showing a similar pattern of distribution, were detected. In challenged fish, the number of immunoreactive cells was significantly increased in the evaluated organs, as well as the melanomacrophage centres showed variable positivity for both antigens. These results indicate that A. salmonicida induced an immune response in challenged turbot, which involved the increase of the activity of iNOS and TNFα in the leukocytic population from kidney and spleen. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Aeromonas salmonicida Ati2 is an effector protein of the type three secretion system.

    PubMed

    Dallaire-Dufresne, Stéphanie; Barbeau, Xavier; Sarty, Darren; Tanaka, Katherine H; Denoncourt, Alix M; Lagüe, Patrick; Reith, Michael E; Charette, Steve J

    2013-09-01

    The bacterium Aeromonas salmonicida, a fish pathogen, uses the type three secretion system (TTSS) to inject effector proteins into host cells to promote the infection. The study of the genome of A. salmonicida has revealed the existence of Ati2, a potential TTSS effector protein. In the present study, a structure-function analysis of Ati2 has been done to determine its role in the virulence of A. salmonicida. Biochemical assays revealed that Ati2 is secreted into the medium in a TTSS-dependent manner. Protein sequence analyses, molecular modelling and biochemical assays demonstrated that Ati2 is an inositol polyphosphate 5-phosphatase, which hydrolyses PtdIns(4,5)P2 and PtdIns(3,4,5)P3 in a way similar to VPA0450, a protein from Vibrio parahaemolyticus having high sequence similarity with Ati2. Mutants of Ati2 with altered amino acids at two different locations in the catalytic site displayed no phosphatase activity. Wild-type and mutant forms of Ati2 were cloned into expression systems for Dictyostelium discoideum, a soil amoeba used as an alternative host to study A. salmonicida virulence. Expression tests allowed us to demonstrate that Ati2 is toxic for the host cell in a catalytic-dependent manner. Finally, this study demonstrated the existence of a new TTSS effector protein in A. salmonicida.

  15. Detection and quantification of Aeromonas salmonicida in fish tissue by real-time PCR.

    PubMed

    Bartkova, S; Kokotovic, B; Skall, H F; Lorenzen, N; Dalsgaard, I

    2017-02-01

    Furunculosis, a septicaemic infection caused by the bacterium Aeromonas salmonicida subsp. salmonicida, currently causes problems in Danish seawater rainbow trout production. Detection has mainly been achieved by bacterial culture, but more rapid and sensitive methods are needed. A previously developed real-time PCR assay targeting the plasmid encoded aopP gene of A. salmonicida was, in parallel with culturing, used for the examination of five organs of 40 fish from Danish freshwater and seawater farms. Real-time PCR showed overall a higher frequency of positives than culturing (65% of positive fish by real-time PCR compared to 30% by a culture approach). Also, no real-time PCR-negative samples were found positive by culturing. A. salmonicida was detected by real-time PCR, though not by culturing, in freshwater fish showing no signs of furunculosis, indicating possible presence of carrier fish. In seawater fish examined after an outbreak and antibiotics treatment, real-time PCR showed the presence of the bacterium in all examined organs (1-482 genomic units mg(-1) ). With a limit of detection of 40 target copies (1-2 genomic units) per reaction, a high reproducibility and an excellent efficiency, the present real-time PCR assay provides a sensitive tool for the detection of A. salmonicida. © 2016 John Wiley & Sons Ltd.

  16. Living in an Extremely Polluted Environment: Clues from the Genome of Melanin-Producing Aeromonas salmonicida subsp. pectinolytica 34melT

    PubMed Central

    Pavan, María Elisa; Pavan, Esteban E.; López, Nancy I.; Levin, Laura

    2015-01-01

    Aeromonas salmonicida subsp. pectinolytica 34melT can be considered an extremophile due to the characteristics of the heavily polluted river from which it was isolated. While four subspecies of A. salmonicida are known fish pathogens, 34melT belongs to the only subspecies isolated solely from the environment. Genome analysis revealed a high metabolic versatility, the capability to cope with diverse stress agents, and the lack of several virulence factors found in pathogenic Aeromonas. The most relevant phenotypic characteristics of 34melT are pectin degradation, a distinctive trait of A. salmonicida subsp. pectinolytica, and melanin production. Genes coding for three pectate lyases were detected in a cluster, unique to this microorganism, that contains all genes needed for pectin degradation. Melanin synthesis in 34melT is hypothesized to occur through the homogentisate pathway, as no tyrosinases or laccases were detected and the homogentisate 1,2-dioxygenase gene is inactivated by a transposon insertion, leading to the accumulation of the melanin precursor homogentisate. Comparative genome analysis of other melanogenic Aeromonas strains revealed that this gene was inactivated by transposon insertions or point mutations, indicating that melanin biosynthesis in Aeromonas occurs through the homogentisate pathway. Horizontal gene transfer could have contributed to the adaptation of 34melT to a highly polluted environment, as 13 genomic islands were identified in its genome, some of them containing genes coding for fitness-related traits. Heavy metal resistance genes were also found, along with others associated with oxidative and nitrosative stresses. These characteristics, together with melanin production and the ability to use different substrates, may explain the ability of this microorganism to live in an extremely polluted environment. PMID:26025898

  17. In vitro studies of Lactobacillus delbrueckii subsp. lactis in Atlantic salmon (Salmo salar L.) foregut: tissue responses and evidence of protection against Aeromonas salmonicida subsp. salmonicida epithelial damage.

    PubMed

    Salinas, Irene; Myklebust, Reidar; Esteban, Maria Angeles; Olsen, Rolf Erik; Meseguer, José; Ringø, Einar

    2008-04-01

    Probiotic bacteria increase the host health status and protect mucosal tissue against pathogen-caused damage in mammalian models. Using an in vitro (intestinal sac) method this study aimed to address (a) the in vitro ability of Lactobacillus delbrueckii subsp. lactis to remain in the gastrointestinal tract of Atlantic salmon (Salmo salar L.) and (b) its ability to prevent cellular damage caused by successive incubation with Aeromonas salmonicida subsp. salmonicida the causative agent of furunculosis. Short in vitro incubation of salmon foregut with (TRITC)-labelled L. delbrueckii subsp. lactis showed that the probiont was able to colonize the enterocyte surface as studied by confocal microscopy. Furthermore, foregut incubated with the probiotic bacteria only, resulted in a healthy intestinal barrier whereas exposure to A. salmonicida disrupted its integrity. However, pre-treatment of salmon intestine with L. delbrueckii subsp. lactis prevented Aeromonas damaging effects. These results are promising in the context of the use of non-autochthonous probiotic bacteria as prophylactic agents against fish bacterial infections in the gastrointestinal tract.

  18. Correlation between acute toxicity for Daphnia magna, Aliivibrio fischeri and physicochemical variables of the leachate produced in landfill simulator reactors.

    PubMed

    Barrios Restrepo, José J; Flohr, Letícia; Melegari, Silvia P; da Costa, Cristina H; Fuzinatto, Cristiane F; de Castilhos, Armando B; Matias, William G

    2017-11-01

    Due to the diversified nature of municipal solid waste and the different stages of its decomposition, the formed leachates result in a complex chemical mixture with toxic potential. These chemicals can cause environmental problems, such as the contamination of surface or groundwater, thus affecting the balance of aquatic ecosystems. The aim of our study was to evaluate the acute toxicity of leachates in Daphnia magna and Aliivibrio fischeri and to identify the main physicochemical variables that influence the toxicity of the landfill leachates produced in reactors within pilot simulations. Acute toxicity tests carried out on D. magna and A. fischeri showed that the leachates produced inside the reactors are highly toxic, presenting EC5048h < 1% for D. magna and EC5015min < 12% for A. fischeri. This result indicates that microcrustaceans are more sensitive to leachates, making them more suitable to our study. Pb showed the highest correlation with EC5048h, suggesting that Pb is the main chemical variable indicative of toxicity for the conditions of the experiment. In smaller scale, phosphate (PO4(3-)) and nitrate (NO(3-)) were the macronutrients that most influenced the toxicity. Clearly, this correlation should be viewed with caution because the synergistic effects of this complex mixture are difficult to observe.

  19. Evaluation of commercially prepared transport systems for nonlethal detection of Aeromonas salmonicida in salmonid fish

    USGS Publications Warehouse

    Cipriano, R.C.; Bullock, G.L.

    2001-01-01

    In vitro studies indicated that commercially prepared transport systems containing Amies, Stuart's, and Cary-Blair media worked equally well in sustaining the viability of the fish pathogen Aeromonas salmonicida, which causes furunculosis. The bacterium remained viable without significant increase or decrease in cell numbers for as long as 48 h of incubation at 18-20??C in Stuart's transport medium; consequently, obtaining mucus samples in such tubes were comparable to on-site detection of A. salmonicida by dilution plate counts on Coomassie Brilliant Blue agar. In three different assays of 100 samples of mucus from Atlantic salmon Salmo salar infected subclinically with A. salmonicida, dilution counts conducted on-site proved more reliable for detecting the pathogen than obtaining the samples in the transport system. In the on-site assays, dilution counts detected the pathogen in 34, 41, and 22 samples, whereas this was accomplished in only 15, 15, and 3 of the respective samples when the transport system was used. In an additional experiment, Arctic char Salvelinus alpinus sustaining a frank epizootic of furunculosis were sampled similarly. Here, too, dilution counts were more predictive of the prevalence of A. salmonicida and detected the pathogen in 46 mucus samples; in comparison, only 6 samples collected by using the transport system were positive. We also observed that the transport system supported the growth of the normal mucus bacterial flora. Particularly predominant among these were motile aeromonads and Pseudomonas fluorescens. In studies of mixed culture growth, two representatives of both of the latter genera of bacteria outgrew A. salmonicida - in some cases, to the total exclusion of the pathogen itself.

  20. Quarantine of Aeromonas salmonicida-harboring ebonyshell mussels (Fusconaia ebena) prevents transmission of the pathogen to brook trout (Salvelinus fontinalis)

    USGS Publications Warehouse

    Starliper, C.E.

    2005-01-01

    Furunculosis, caused by the bacterium Aeromonas salmonicida, was artificially induced in brook trout (Salvelinus fontinalis) in an experimental tank. Ebonyshells (Fusconaia ebena) were placed to cohabit with these fish to acquire the pathogen through siphoning. After 2 wk of cohabitation, 10 of the mussels were assayed by bacterial culture and all were found to harbor A. salmonicida. The mean cell count from soft tissue homogenates was 1.84 ?? 105 cfu/g, which comprised an average 14.41% of the total bacteria isolated from tissues. From the fluids, a mean of 2.84 ?? 105 A. salmonicida cfu/mL was isolated, which comprised an average of 17.29% of the total bacterial flora. The mussels were removed from the cohabitation tank and distributed equally among five previously disinfected tanks, 35 per tank. The F. ebena in each tank were allowed to depurate A. salmonicida for various durations: 1, 5, 10, 15 or 30 days. After each group had depurated for their assigned time, 10 were assayed for bacteria, tank water was tested, and 20 pathogen-free bioindicator brook trout were added to cohabit with the remaining mussels. Depuration was considered successful if A. salmonicida was not isolated from tank water or the mussels, and there was no infection or mortality to bioindicator fish. After 1 day of depuration, A. salmonicida was not isolated from the soft tissues; however, it was isolated from one of the paired fluids (10% prevalence). The tank water tested positive, and the bioindicator fish became infected and died. From the 5-day depuration group, A. salmonicida was not isolated from soft tissues, but was isolated from three fluids (30%; mean = 1.56 ?? 102 cfu/mL). Tank water from the 5-day group was negative, and there was no mortality among the bioindicator fish. However, A. salmonicida was isolated from 2 of 20 fish at the end of the 14-day observation period. One F. ebena fluid sample was positive for A. salmonicida from the 10-day depuration group, but none of the

  1. Toxicity of individual pharmaceuticals and their mixtures to Aliivibrio fischeri: Evidence of toxicological interactions in binary combinations.

    PubMed

    Di Nica, Valeria; Villa, Sara; Finizio, Antonio

    2017-03-01

    The combined toxicities of binary mixtures of veterinary pharmaceutical active compounds were examined using the bioluminescent bacterium Aliivibrio fischeri as a test organism (Microtox® test). Mixtures were prepared at an equitoxic ratio that corresponded to the inhibitory concentration, 10% (IC10) of individual pharmaceutical active compounds. In addition, the toxicity was determined of a multicomponent mixture that contained all of the investigated pharmaceutical active compounds mixed at a ratio corresponding to their individual predicted no-effect concentration (PNEC) values. The experimental results were successively compared with those obtained by applying the 2 most widely used models for predicting mixture toxicity, the concentration addition (CA) and independent action (IA) models. Although the toxicity of the multicomponent mixture tested was well predicted by the CA and IA models, deviations from the model predictions were found for almost all of the binary mixtures. The deviations from the CA and IA models were greater at lower concentrations, particularly when diclofenac sodium and amoxicillin were present in the mixture. Based on these results, another hypothesis was tested, that of toxicological interactions occurring in binary mixtures (in the direction of synergistic or antagonistic effects), by applying the combination index method, which allowed for computerized quantification of synergism, the additive effect and antagonism. The application of this method confirmed, for at least half of the binary combinations, the clear presence of synergistic deviations at the lowest tested concentrations, with a tendency toward antagonism at the higher ones. In 1 case, a relevant antagonistic interaction was observed. Environ Toxicol Chem 2017;36:815-822. © 2016 SETAC.

  2. Aeromonas salmonicida Binds Differentially to Mucins Isolated from Skin and Intestinal Regions of Atlantic Salmon in an N-Acetylneuraminic Acid-Dependent Manner

    PubMed Central

    Padra, János T.; Sundh, Henrik; Jin, Chunsheng; Karlsson, Niclas G.; Sundell, Kristina

    2014-01-01

    Aeromonas salmonicida subsp. salmonicida infection, also known as furunculosis disease, is associated with high morbidity and mortality in salmonid aquaculture. The first line of defense the pathogen encounters is the mucus layer, which is predominantly comprised of secreted mucins. Here we isolated and characterized mucins from the skin and intestinal tract of healthy Atlantic salmon and studied how A. salmonicida bound to them. The mucins from the skin, pyloric ceca, and proximal and distal intestine mainly consisted of mucins soluble in chaotropic agents. The mucin density and mucin glycan chain length from the skin were lower than were seen with mucin from the intestinal tract. A. salmonicida bound to the mucins isolated from the intestinal tract to a greater extent than to the skin mucins. The mucins from the intestinal regions had higher levels of sialylation than the skin mucins. Desialylating intestinal mucins decreased A. salmonicida binding, whereas desialylation of skin mucins resulted in complete loss of binding. In line with this, A. salmonicida also bound better to mammalian mucins with high levels of sialylation, and N-acetylneuraminic acid appeared to be the sialic acid whose presence was imperative for binding. Thus, sialylated structures are important for A. salmonicida binding, suggesting a pivotal role for sialylation in mucosal defense. The marked differences in sialylation as well as A. salmonicida binding between the skin and intestinal tract suggest interorgan differences in the host-pathogen interaction and in the mucin defense against A. salmonicida. PMID:25287918

  3. Survival of cells and DNA of Aeromonas salmonicida released into aquatic microcosms.

    PubMed

    Deere, D; Porter, J; Pickup, R W; Edwards, C

    1996-09-01

    The survival of the bacterial fish pathogen Aeromonas salmonicida, and persistence of its DNA, were monitored in aquatic microcosms using selective culture and most probable number PCR. Bacterial cells and naked DNA were released into natural non-sterile microcosms consisting of lake sediment overlayered with lake water. Two different types of surface sediment were used. One was sandy in character, taken from the shoreline whilst the other was a littoral loamy surface mud. Inoculated cells and naked DNA became undetectable from water overlayers within 4 weeks of release. Colony counts of Aer. salmonicida declined below detectable limits after 4 weeks in loamy sediment or 7 weeks in sandy sediment; however, naked DNA and DNA from released cells remained detectable for more than 13 weeks.

  4. Precipitating antibody against Aeromonas salmonicida in serums of inbred albino Rainbow Trout (Salmo gairdneri)

    USGS Publications Warehouse

    Anderson, Douglas P.; Klontz, George W.

    1970-01-01

    Precipitins in albino rainbow trout serums were demonstrated by gel diffusion after a single parenteral exposure to the soluble antigens of Aeromonas salmonicida. The fraction of the serum containing antibody activity against the presented antigens was shown by immunoelectrophoresis to be in the nonmigrating region. This corresponded to the beta-2 fraction of rabbit serum. An antibody-containing component comparable with rabbit gamma globulin was not detected.

  5. Growth inhibition of Aeromonas salmonicida and Yersinia ruckeri by disinfectants containing peracetic acid.

    PubMed

    Meinelt, Thomas; Phan, Thy-My; Behrens, Sascha; Wienke, Andreas; Pedersen, Lars-Flemming; Liu, Dibo; Straus, David L

    2015-04-08

    Peracetic acid (PAA) is a therapeutic agent used for disinfection in aquaculture, but it must be investigated thoroughly in order to mitigate diseases without harming the fish. Successful disinfectants (like PAA) should not leave dangerous residues in the environment in order to successfully contribute to sustainable aquaculture. The aim of our study was to compare the effectiveness of 6 commercial PAA products with different molecular PAA:H2O2 ratios to reduce bacterial growth of Aeromonas salmonicida and Yersinia ruckeri and to determine effective concentrations and exposure times. All products reduced colony-forming units (CFUs) of A. salmonicida and Y. ruckeri. Products with higher molecular PAA:H2O2 ratios inhibited growth better than products with lower molecular PAA:H2O2 ratios at the same PAA concentration; this indicates that H2O2 is not the driving force in the reduction of A. salmonicida and Y. ruckeri growth by PAA in vitro. The practical application of the products with high molecular PAA:H2O2 ratios should be prioritized if these pathogens are diagnosed.

  6. Antimicrobial effect of the Biotronic® Top3 supplement and efficacy in protecting rainbow trout (Oncorhynchus mykiss) from infection by Aeromonas salmonicida subsp. salmonicida.

    PubMed

    Menanteau-Ledouble, Simon; Krauss, Ines; Goncalves, Rui Alexandre; Weber, Barbara; Santos, Gonçalo Abreu; El-Matbouli, Mansour

    2017-03-18

    Demand for more environmentally friendly practices have led to the adoption of several feed supplements by the fish farming industry. In the present study, we investigated a commercially available formula that includes a mixture of three compounds: organic acids, a phytochemical and Biomin® Permeabilizing Complex. This mixture demonstrated antimicrobial properties in vitro and was able to inhibit growth of multiple species of aquatic bacterial pathogens, including Aeromonas salmonicida. Bacterial challenge was performed using A. salmonicida and three exposure routes: intra-peritoneal injection, immersion, and cohabitation. Mortality rates following infection by injection were significantly decreased in the fish that had received the supplemented feed. Fish infected through the other routes did not show a significant difference in mortality. In term of farming performance, while the fish that had received the feed supplement showed an improvement in weight gain and final weight, these changes were not found to be statistically significant. Similarly, no significant difference was observed in the feed conversion ratio. The results of this study suggest that this feed supplement may be effective at protecting rainbow trout from fish furunculosis.

  7. Historical record of Yersinia ruckeri and Aeromonas salmonicida among sea-run Atlantic salmon (Salmo salar) in the Penobscot River

    USGS Publications Warehouse

    Cipriano, R.C.; Coll, J.

    2005-01-01

    Despite restoration efforts, only about 2,000 Atlantic salmon (Salmo salar) salmon have annually returned to New England Rivers and more than 71% of these fish migrate to the Penobscot River alone. This report provides a historical compilation on the prevalence's of both Yersinia ruckeri, cause of enteric redmouth disease, and Aeromonas salmonicida, cause of furunculosis, among mature sea-run Atlantic salmon that returned to the Penobscot River from 1976 to 2003. Aeromonas salmonicida was detected in 28.6% and Yersinia ruckeri was detected among 50% of the yearly returns. Consequently, Atlantic salmon that return to the river are potential reservoirs of infection.

  8. Antimicrobial Resistance and Plasmid Profile of Bacterial Strains Isolated from the Urbanized Eltsovka-1 River (Russia).

    PubMed

    Lobova, Tatiana I; Yemelyanova, Elena; Andreeva, Irina S; Puchkova, Larisa I; Repin, Vladimir Ye

    2015-08-01

    Antimicrobial resistance and plasmid profile of Gram-positive and Gram-negative bacterial strains isolated from the urbanized Eltsovka-1 River (Russia) were investigated. Sequencing of the 16S rRNA of of G+ strains showed 99-100% identity to that of Bacillus aerophilus, Bacillus altitudinis, Bacillus amyloliquefaciens, Bacillus anthrancis, Bacillus barbaricus, Bacillus cereus, Bacillus flexus, Bacillus indriensis, Bacillus stratosphericus, Bacillus subtilis subsp. subtilis, Bacillus thuringiensis, Streptomyces albidoflavus, Streptomyces albus, Streptomyces exfoliatus, Streptomyces odorifer, and Streptomyces sampsonii. Sequencing of the 16S rRNA of G-strains was similar in 99-100% to that of Aeromonas bestiarum, Aeromonas encheleia, Aeromonas hydrophila, A. hydrophila subsp. anaerogenes, A. hydrophila subsp. dhakensis, Aeromonas media, Aeromonas molluscorum, Aeromonas popoffii, Aeromonas salmonicida subsp. masoucida, A. salmonicida subsp. pectinolytica, A. salmonicida subsp. salmonicida, Aeromonas punctata, Aeromonas sobria, and Shewanella putrefaciens. The highest percentage (88.4%) of strains was resistant to polymyxin B followed by 69% to lincomycin, 61.5% to benzilpenicillin, 57.7% to ampicillin, and 50% to carbenicillin. A low level of resistance (4%) was found to kanamycin (8%), to streptomycin (11.5%), to neomycin and tetracycline, and (15%) to erythromycin. No resistance was found to gentamycin, monomycin, and chloroamphenicol. The majority (80.7%) of strains was multidrug-resistant. Ninety-two percent of all strains carried plasmid DNA of various sizes.

  9. Enhancement of anti-Aeromonas salmonicida activity in Atlantic salmon (Salmo salar) macrophages by a mannose-binding lectin

    USGS Publications Warehouse

    Ottinger, C.A.; Johnson, S.C.; Ewart, K.V.; Brown, L.L.; Ross, N.W.

    1999-01-01

    We investigated the effects of a calcium-dependent mannose-binding lectin isolated from the serum of Atlantic salmon on Aeromonassalmonicida viability and the anti-A. salmonicida activity of Atlantic salmon macrophages. In the absence of other factors, binding of this lectin at concentrations of 0.8, 4.0 and 20.0 ng ml−1 to virulent A. salmonicida failed to significantly reduce (P>0.05) cell viability. However, binding of the lectin to A. salmonicida did result in significant (P≤0.05) dose-dependent increases in phagocytosis, and bactericidal activity. Significant increases (P≤0.05) were also observed in phagocyte respiratory burst activity within the lectin concentration range of 4.0–20.0 ng ml−1 but the stimulation was not dose dependent at these lectin concentrations. At the lowest lectin concentration tested (0.32 ng ml−1), a significant decrease (P≤0.05) in respiratory burst was observed. The structure and activity of this lectin are similar to that of mammalian mannose-binding lectins, which are known to play a pivotal role in innate immunity. The presence of this lectin may be an important defense mechanism against Gram-negative bacteria such as A. salmonicida.

  10. Transferable, multiple antibiotic and mercury resistance in Atlantic Canadian isolates of Aeromonas salmonicida subsp. salmonicida is associated with carriage of an IncA/C plasmid similar to the Salmonella enterica plasmid pSN254

    PubMed Central

    McIntosh, Douglas; Cunningham, Michelle; Ji, Baijing; Fekete, Frank A.; Parry, Erin M.; Clark, Sarah E.; Zalinger, Zachary B.; Gilg, Ilana C.; Danner, G. Russell; Johnson, Keith A.; Beattie, Mike; Ritchie, Rachael

    2008-01-01

    Objectives The aim of this study was to examine the molecular basis for multiple antibiotic and mercury resistance in Canadian isolates of Aeromonas salmonicida subsp. salmonicida. Methods Phenotypic and genotypic methods were employed to identify plasmid-associated antibiotic and mercury resistance genes and to determine the organization of those genes in multidrug-resistant (MDR) A. salmonicida isolates. Results The MDR phenotype was transferable via conjugation using Escherichia coli, Aeromonas hydrophila and Edwardseilla tarda as recipients. Antibiotic and mercury resistance genes were carried by a conjugative IncA/C plasmid. Three distinct antibiotic resistance cassettes were characterized; first a class I integron containing an aadA7 gene encoding for an aminoglycoside-3′-adenyltransferase, the second cassette showed 99.9% nucleotide sequence homology to a cassette previously identified in the Salmonella enterica IncA/C plasmid pSN254, containing floR, tetA, sulII and strA/strB sequences. The third cassette showed 100% nucleotide sequence similarity to a transposon-like element, containing a blaCMY-2 β-lactamase in association with sugE and blc sequences. This element is known to be widely distributed among clinical and food-borne Salmonella and other Enterobacteriaceae throughout Asia and the United States. Mercury resistance was linked to the presence of a mer operon that showed 100% nucleotide sequence homology to the mer operon carried by plasmid pSN254. Conclusions Each MDR A. salmonicida isolate carried the same plasmid, which was related to plasmid pSN254. This is the first report of plasmid-mediated florfenicol-resistant A. salmonicida in North America. In addition, it is the first report of a plasmid-associated AmpC β-lactamase sequence in a member of the Aeromonadaceae. PMID:18375380

  11. Lux-operon of the Marine Psychrophilic Bacteria Aliivibrio logei: a Comparative Analysis of the LuxR1/LuxR2 Regulatory Activity in Escherichia coli cells.

    PubMed

    Khrulnova, Svetlana A; Baranova, Ancha; Bazhenov, Sergey V; Goryanin, Ignatiy I; Konopleva, Maria N; Maryshev, Ivan V; Salykhova, Albina I; Vasilyeva, Alexandra V; Manukhov, Ilya V; Zavilgelsky, Gennadii B

    2016-02-03

    The lux-operon оf the psychrophilic bioluminescent bacterium A. logei is regulated by Quorum Sensing (QS). The key components of this system are LuxI that catalyzes the synthesis of autoinducer (AI) and LuxR that activates the transcription of entire lux-operon. The lux-operon of A. logei contains two copies of luxR gene: luxR1 and luxR2. In the present study lux-operon sequence analysis from 16 strains of A. logei, isolated from cold habitats of the White, Baltic, Okhotsk and Bering Seas was carried out. The phylogenetic analysis showed that all isolated strains of A. logei have both copies of luxR genes which are homologous to luxR genes of relative A. salmonicida. LuxR1 and LuxR2 activity evaluation showed that LuxR2 remain active at significantly lower concentration of AI (10-9M) compared to LuxR1 which is activate only at high AI concentration (10-6М). As QS response is already prominent at AI concentrations as low as 10-8 - 10-9M, we conclude that LuxR2 is a main activator of the lux-operon of A. logei. The thermolabilities of LuxR1 and LuxR2 are similar and exceed that of LuxR of mesophilic bacterium A. fischeri. As oppose to LuxR2, LuxR1 is not a substrate of Lon protease and does not require the chaperonin GroEL/ES for its folding.

  12. Survival of two bacterial fish pathogens (Aeromonas salmonicida and the Enteric Redmouth Bacterium) in ozonated, chlorinated, and untreated waters

    USGS Publications Warehouse

    Wedemeyer, Gary A.; Nelson, Nancy C.

    1977-01-01

    Ozone and chlorine inactivation curves were determined in three water types at 20 °C for the destruction of the fish pathogens Aeromonas salmonicida, the etiologic agent of furunculosis, and the enteric redmouth bacterium (ERM). In phosphate-buffered distilled water, 0.01 mg/ℓ ozone inactivated 103 cells/ml of ERM and A. salmonicida in 1/2 and 10 min, respectively. Chlorine at this concentration had little effect on either pathogen and a residual of at least 0.05 mg/ℓ was needed to achieve a complete kill within a 10-min contact time. In soft lake water (30 mg/ℓ as CaCO3) a chlorine residual of 0.1 mg/ℓ rapidly  inactivated A. salmonicida and ERM but in hard water (120 mg/ℓ) A. salmonicida was more resistant and 0.2 mg/ℓ chlorine was required. Ozonation of the two lake waters at 90 mg O3∙h−1∙ℓ−1 (equivalent to a 0.01 mg/ℓ residual in ozone demand-free water) was required to destroy both pathogens within 10 min.In untreated soft lake water 103 cells/ml of A. salmonicida survived only 2 days, while the ERM bacterium (103 cells/ml) survived even after 20 day s in soft and hard untreated lake waters.

  13. Antimicrobial susceptibility testing of aquatic bacteria: quality control disk diffusion ranges for Escherichia coli ATCC 25922 and Aeromonas salmonicida subsp. salmonicida ATCC 33658 at 22 and 28 degrees C.

    PubMed

    Miller, R A; Walker, R D; Baya, A; Clemens, K; Coles, M; Hawke, J P; Henricson, B E; Hsu, H M; Mathers, J J; Oaks, J L; Papapetropoulou, M; Reimschuessel, R

    2003-09-01

    Quality control (QC) ranges for disk diffusion susceptibility testing of aquatic bacterial isolates were proposed as a result of a multilaboratory study conducted according to procedures established by the National Committee for Clinical Laboratory Standards (NCCLS). Ranges were proposed for Escherichia coli ATCC 25922 and Aeromonas salmonicida subsp. salmonicida ATCC 33658 at 22 and 28 degrees C for nine different antimicrobial agents (ampicillin, enrofloxacin, erythromycin, florfenicol, gentamicin, oxolinic acid, oxytetracycline, ormetoprim-sulfadimethoxine, and trimethoprim-sulfamethoxazole). All tests were conducted on standard Mueller-Hinton agar. With >/=95% of all data points fitting within the proposed QC ranges, the results from this study comply with NCCLS guidelines and have been accepted by the NCCLS Subcommittee for Veterinary Antimicrobial Susceptibility Testing. These QC guidelines will permit greater accuracy in interpreting results and, for the first time, the ability to reliably compare susceptibility test data between aquatic animal disease diagnostic laboratories.

  14. Antimicrobial Susceptibility Testing of Aquatic Bacteria: Quality Control Disk Diffusion Ranges for Escherichia coli ATCC 25922 and Aeromonas salmonicida subsp. salmonicida ATCC 33658 at 22 and 28°C

    PubMed Central

    Miller, R. A.; Walker, R. D.; Baya, A.; Clemens, K.; Coles, M.; Hawke, J. P.; Henricson, B. E.; Hsu, H. M.; Mathers, J. J.; Oaks, J. L.; Papapetropoulou, M.; Reimschuessel, R.

    2003-01-01

    Quality control (QC) ranges for disk diffusion susceptibility testing of aquatic bacterial isolates were proposed as a result of a multilaboratory study conducted according to procedures established by the National Committee for Clinical Laboratory Standards (NCCLS). Ranges were proposed for Escherichia coli ATCC 25922 and Aeromonas salmonicida subsp. salmonicida ATCC 33658 at 22 and 28°C for nine different antimicrobial agents (ampicillin, enrofloxacin, erythromycin, florfenicol, gentamicin, oxolinic acid, oxytetracycline, ormetoprim-sulfadimethoxine, and trimethoprim-sulfamethoxazole). All tests were conducted on standard Mueller-Hinton agar. With ≥95% of all data points fitting within the proposed QC ranges, the results from this study comply with NCCLS guidelines and have been accepted by the NCCLS Subcommittee for Veterinary Antimicrobial Susceptibility Testing. These QC guidelines will permit greater accuracy in interpreting results and, for the first time, the ability to reliably compare susceptibility test data between aquatic animal disease diagnostic laboratories. PMID:12958263

  15. Crystallization and preliminary X-ray diffraction analysis of a cold-adapted catalase from Vibrio salmonicida

    SciTech Connect

    Riise, Ellen Kristin; Lorentzen, Marit Sjo; Helland, Ronny; Willassen, Nils Peder

    2006-01-01

    Monoclinic (P2{sub 1}) crystals of a His-tagged form of V. salmonicida catalase without cofactor diffract X-rays to 1.96 Å. Catalase (EC 1.11.1.6) catalyses the breakdown of hydrogen peroxide to water and molecular oxygen. Recombinant Vibrio salmonicida catalase (VSC) possesses typical cold-adapted features, with higher catalytic efficiency, lower thermal stability and a lower temperature optimum than its mesophilic counterpart from Proteus mirabilis. Crystals of VSC were produced by the hanging-drop vapour-diffusion method using ammonium sulfate as precipitant. The crystals belong to the monoclinic space group P2{sub 1}, with unit-cell parameters a = 98.15, b = 217.76, c = 99.28 Å, β = 110.48°. Data were collected to 1.96 Å and a molecular-replacement solution was found with eight molecules in the asymmetric unit.

  16. Bisucaberin--a dihydroxamate siderophore isolated from Vibrio salmonicida, an important pathogen of farmed Atlantic salmon (Salmo salar).

    PubMed

    Winkelmann, Gunther; Schmid, Dietmar G; Nicholson, Graeme; Jung, Günther; Colquhoun, Duncan J

    2002-06-01

    A siderophore of the bacterial fish pathogen, Vibrio salmonicida, was isolated from low-iron culture supernatant and structurally characterized as bisucaberin by FTICR- and FAB-MS, NMR and GC-MS analysis of the hydrolysis products. Although the cyclic dihydroxamate bisucaberin has previously been isolated from a marine bacterium, Alteromonas haloplanktis, its involvement in cold-water vibriosis of Atlantic salmon (Salmon salar) is novel. Bisucaberin production in iron-limited media was highest at temperatures around and below 10 degrees C, correlating well with temperatures at which outbreaks of cold-water vibriosis occur. Due to the very high stability constant of K = 32.2, bisucaberin is a most efficient iron scavenger which may contribute to the virulence of V. salmonicida in Atlantic salmon.

  17. Simultaneous Detection of Aeromonas salmonicida, Flavobacterium psychrophilum, and Yersinia ruckeri, Three Major Fish Pathogens, by Multiplex PCR

    PubMed Central

    del Cerro, A.; Marquez, I.; Guijarro, J. A.

    2002-01-01

    A multiplex PCR assay based on the 16S rRNA genes was developed for the simultaneous detection of three major fish pathogens, Aeromonas salmonicida, Flavobacterium psychrophilum, and Yersinia ruckeri. The assay proved to be specific and as sensitive as each single PCR assay, with detection limits in the range of 6, 0.6, and 27 CFU for A. salmonicida, F. psychrophilum, and Y. ruckeri, respectively. The assay was useful for the detection of the bacteria in artificially infected fish as well as in fish farm outbreaks. Results revealed that this multiplex PCR system permits a specific, sensitive, reproducible, and rapid method for the routine laboratory diagnosis of infections produced by these three bacteria. PMID:12324372

  18. Virulence and persistence of rough and smooth forms of Aeromonas salmonicida inoculated into coho salmon (Oncorhynchus kisutch)

    USGS Publications Warehouse

    Anderson, Douglas P.

    1972-01-01

    Virulent isolates of Aeromonas salmonicida showed a majority of smooth colonies, while the attenuated isolates displayed mostly rough colonies. A lesion occurred at the site of inoculation when one of the rough forms was inoculated into yearling coho salmon, but few mortalities were recorded even though the rough forms were readily recovered from both the lesion and the kidney. The fish inoculated with the same dosage of smooth forms all died within 96 hr of inoculation.

  19. Immunization of pacific salmon: comparison of intraperitoneal injection and hyperosmotic infiltration of Vibrio anguillarum and Aeromonas salmonicida bacterins

    USGS Publications Warehouse

    Antipa, Ross; Amend, Donald F.

    1977-01-01

    Two methods of immunizing fish, intraperitoneal (i.p.) injection and hyperosmotic infiltration, were compared for control of vibriosis and furunculosis in pen-reared coho salmon (Oncorhynchus kisutch) and chinook salmon (O. tshawytscha). Both methods provided significant protection against vibriosis under field test conditions. In coho salmon, hyperosmotic infiltration provided the best protection and fastest rise in antibody titer of seven treatments tested. In chinook salmon, hyperosmotic infiltration of Vibrio anguillarum and Aeromonas salmonicida vaccines resulted in 83.3% survival in comparison with 28.7% survival in controls. Both i.p. injection and hyperosmotic infiltration of V. anguillarum and A. salmonicida bacterins resulted in production of serum antibodies specific for each respective pathogen. Vaccination with bivalent V. anguillarum–A.salmonicida vaccines produced antibodies to both pathogens, and provided protection against vibriosis. Growth rates of vaccinated coho salmon were not significantly different from controls.

  20. General baseline toxicity QSAR for nonpolar, polar and ionisable chemicals and their mixtures in the bioluminescence inhibition assay with Aliivibrio fischeri.

    PubMed

    Escher, Beate I; Baumer, Andreas; Bittermann, Kai; Henneberger, Luise; König, Maria; Kühnert, Christin; Klüver, Nils

    2017-03-22

    The Microtox assay, a bioluminescence inhibition assay with the marine bacterium Aliivibrio fischeri, is one of the most popular bioassays for assessing the cytotoxicity of organic chemicals, mixtures and environmental samples. Most environmental chemicals act as baseline toxicants in this short-term screening assay, which is typically run with only 30 min of exposure duration. Numerous Quantitative Structure-Activity Relationships (QSARs) exist for the Microtox assay for nonpolar and polar narcosis. However, typical water pollutants, which have highly diverse structures covering a wide range of hydrophobicity and speciation from neutral to anionic and cationic, are often outside the applicability domain of these QSARs. To include all types of environmentally relevant organic pollutants we developed a general baseline toxicity QSAR using liposome-water distribution ratios as descriptors. Previous limitations in availability of experimental liposome-water partition constants were overcome by reliable prediction models based on polyparameter linear free energy relationships for neutral chemicals and the COSMOmic model for charged chemicals. With this QSAR and targeted mixture experiments we could demonstrate that ionisable chemicals fall in the applicability domain. Most investigated water pollutants acted as baseline toxicants in this bioassay, with the few outliers identified as uncouplers or reactive toxicants. The main limitation of the Microtox assay is that chemicals with a high melting point and/or high hydrophobicity were outside of the applicability domain because of their low water solubility. We quantitatively derived a solubility cut-off but also demonstrated with mixture experiments that chemicals inactive on their own can contribute to mixture toxicity, which is highly relevant for complex environmental mixtures, where these chemicals may be present at concentrations below the solubility cut-off.

  1. Effect of a phytogenic feed additive on the susceptibility of Onchorhynchus mykiss to Aeromonas salmonicida.

    PubMed

    Menanteau-Ledouble, S; Krauss, I; Santos, G; Fibi, S; Weber, B; El-Matbouli, M

    2015-06-29

    In recent years, feed additives have increasingly been adopted by the aquaculture industry. These supplements not only offer an alternative to antibiotics but have also been linked to enhanced growth performance. However, the literature is still limited and provides contradictory information on their effectiveness. This is mainly due to the wide variety of available products and their complex mechanisms of action. Phytogenic feed additives have been shown to have antimicrobial effects and can improve growth performance. In the present study, we investigated the susceptibility of several fish pathogenic bacteria to a phytogenic essential oil product in vitro. In addition, we determined the protective effect of a commercial phytogenic feed additive containing oregano, anis and citrus oils on the resistance of rainbow trout Oncorhynchus mykiss to infection by Aeromonas salmonicida. The bacterium was administered through 3 different routes: intra-peritoneal injection, immersion in a bacterial solution and cohabitation with infected fish. Mortality rates were significantly lower in infected rainbow trout that had received the feed additive: the overall mortality rate across all routes of infection was 18% in fish fed a diet containing the additive compared to 37% in fish that received unsupplemented feed. The route of infection also significantly impacted mortality, with average mortality rates of 60, 17.5 and 5% for intra-peritoneal injection, immersion and cohabitation, respectively. In general, fish were better protected against infection by immersion than infection by injection.

  2. Recovery of a fish pathogenic bacterium, Aeromonas salmonicida, from ebonyshell mussels Fusconaia ebena using nondestructive sample collection procedures

    USGS Publications Warehouse

    Starliper, C.E.

    2008-01-01

    Refugia are increasingly being used to maintain and propagate imperiled freshwater mussels for future population augmentations. Success for this endeavor is dependent on good husbandry, including a holistic program of resource health management. A significant aspect to optimal health is the prevention or control of infectious diseases. Describing and monitoring pathogens and diseases in mussels involves examination of tissues or samples collected from an appropriate number of individuals that satisfies a certain confidence level for expected prevalences of infections. In the present study, ebonyshell mussels Fusconaia ebena were infected with a fish pathogenic bacterium, Aeromonas salmonicida, through their cohabitation with diseased brook trout Salvelinus fontinalis. At a 100% prevalence of infection, the F. ebena were removed from the cohabitation tank to clean tanks that were supplied with pathogen-free water, which initiated their depuration of A. salmonicida. Three samples (nondestructive fluid, mantle, hemolymph) collected using nondestructive procedures were compared with fluids and soft tissue homogenates collected after sacrificing the mussels for recovery of the bacterium during this period of depuration. Nondestructive sample collections, especially ND fluid, provide a comparable alternative to sacrificing mussels to determine pathogen status.

  3. Cold adapted features of Vibrio salmonicida catalase: characterisation and comparison to the mesophilic counterpart from Proteus mirabilis.

    PubMed

    Lorentzen, Marit Sjo; Moe, Elin; Jouve, Hélène Marie; Willassen, Nils Peder

    2006-10-01

    The gene encoding catalase from the psychrophilic marine bacterium Vibrio salmonicida LFI1238 was identified, cloned and expressed in the catalase-deficient Escherichia coli UM2. Recombinant catalase from V. salmonicida (VSC) was purified to apparent homogeneity as a tetramer with a molecular mass of 235 kDa. VSC contained 67% heme b and 25% protoporphyrin IX. VSC was able to bind NADPH, react with cyanide and form compounds I and II as other monofunctional small subunit heme catalases. Amino acid sequence alignment of VSC and catalase from the mesophilic Proteus mirabilis (PMC) revealed 71% identity. As for cold adapted enzymes in general, VSC possessed a lower temperature optimum and higher catalytic efficiency (k (cat)/K (m)) compared to PMC. VSC have higher affinity for hydrogen peroxide (apparent K (m)) at all temperatures. For VSC the turnover rate (k (cat)) is slightly lower while the catalytic efficiency is slightly higher compared to PMC over the temperature range measured, except at 4 degrees C. Moreover, the catalytic efficiency of VSC and PMC is almost temperature independent, except at 4 degrees C where PMC has a twofold lower efficiency compared to VSC. This may indicate that VSC has evolved to maintain a high efficiency at low temperatures.

  4. The adjuvant effect of low frequency ultrasound when applied with an inactivated Aeromonas salmonicida vaccine to rainbow trout (Oncorhynchus mykiss).

    PubMed

    Cobo Labarca, Cristóbal; Makhutu, Mary; Lumsdon, Alexander E; Thompson, Kim D; Jung, Rainer; Kloas, Werner; Knopf, Klaus

    2015-03-10

    Vaccine adjuvants are classified according to their properties of either inducing the persistence of antigens within the animal after immunisation and/or activation of the animal's immune response. The adjuvant effect of low intensity low frequency sonophoresis (LFS) was tested in rainbow trout using an Aeromonas salmonicida bacterin vaccine administered by immersion vaccination using LFS at 37 kHz. The adjuvant effect obtained with LFS was compared with that of normal immersion or intraperitoneal injection vaccination. Quantitative PCR was used to measure bacterial DNA in vaccinated fish up to 35 days post-vaccination, while RT-qPCR was used to assess gene expression during the early and late immune response post-vaccination. Results showed that antigen uptake in the gills was significantly higher in the group exposed to low intensity LFS compared to the other two vaccination groups 15 min post-vaccination, but this initially high uptake did not persist over the rest of the experiment. In the kidney, by comparison, the vast majority of the samples analysed did not show the presence or persistence of the bacterin. Showing that the route of vaccine uptake using the A. salmonicida bacterin, does not influence the persistence of the bacterin in the gills or the kidney. On the other hand, LFS induced a higher inflammatory response and T-helper cell activation, characterized by a significant up-regulation of interleukin-8 (IL-8), IL-1ß and CD-4, respectively. The expression of Ig-M, Ig-T and Ig-D was up-regulated in gills (being significant for Ig-M), but not in the spleen and kidney of the sonicated group. Conversely, Ig-M was up-regulated in the spleen of the non-sonicated groups, but not in the sonicated group. This highlights the ability of ultrasound to enhance mucosal immunity. It remains to be established whether the up-regulation of Ig-M in gills would be sufficient to offer protection in fish infected with A. salmonicida.

  5. Optimization of nested polymerase chain reaction assays for identification of Aeromonas salmonicida, Yersinia ruckeri and Flavobacterium psychrophilum

    USGS Publications Warehouse

    Taylor, P.W.; Winton, J.R.

    2002-01-01

    Nested polymerase chain reaction (PCR) assays were developed using first-round primers complementary to highly conserved regions within the bacterial 16S ribosomal RNA (rRNA) gene (universal eubacterial primers) and second-round primers specific for sequences within the 16S rRNA genes of Aeromonas salmonicida, Yersinia ruckeri, andFlavobacterium psychrophilum. Following optimization of the MgCl2 concentration and primer annealing temperature, PCR employing the universal eubacterial primers was used to amplify a 1,500-base-pair (bp) product visible in agarose gels stained with ethidium bromide. The calculated detection limit of this single-round assay was less than 1.4 × 104 colony-forming units (CFU) per reaction for all bacterial species tested. Single-round PCR using primer sets specific for A. salmonicida, Y. ruckeri, and F. psychrophilumamplified bands of 271, 575, and 1,100 bp, respectively, with detection limits of less than 1.4 × 104, 1.4 × 105, and 1.4 × 105 CFU per reaction. Using the universal eubacterial primers in the first round and the species-specific primer sets in the second round of nested PCR assays improved the detection ability by approximately four orders of magnitude to fewer than 14 CFU per sample for each of the three bacterial species. Such nested assays could be adapted to a wide variety of bacterial fish pathogens for which 16S sequences are available.

  6. Differences in detection of Aeromonas salmonicida in covertly infected salmonid fishes by the stress-inducible furunculosis test and culture-based assays

    USGS Publications Warehouse

    Cipriano, R.C.; Ford, L.A.; Smith, D.R.; Schachte, J.H.; Petrie, C.J.

    1997-01-01

    Accurate detection of Aeromonas salmonicida subsp. salmonicida (the cause of furunculosis disease) in covertly infected salmonids is difficult and is a cause of concern for those involved in fish health inspection and resource management programs. In this study, we examined populations of brook trout Salvelinus fontinalis, Atlantic salmon Salmo salar, and lake trout Salvelinus namaycush that previously sustained natural episodes of furunculosis. Consequently, the sampled fish were presumed to harbor latent infections. Mucus, gill, liver, kidney, heart, spleen, and intestine samples (N = 100 fish per group sampled) were processed and examined by (1) direct dilution counts and (2) quadrant streaking after a 48-h pre-enrichment in trypticase soy broth (TSB). Another subsample of fish from each group was then subjected to stress-inducible furunculosis tests. Stress tests detected A. salmonicida in three of four groups of fish that were examined whereas the pathogen was detected in only two of the groups analyzed with culture-based assays. Although pre-enrichment in TSB enhanced detection within internal sampling sites including the liver, heart, spleen, and kidney, enrichment did not enhance detection from mucus, gill, or intestinal samples.

  7. Bactericidal activity of juvenile chinook salmon macrophages against Aeromonas salmonicida after exposure to live or heat-killed Renibacterium salmoninarum or to soluble proteins produced by R. salmoninarum

    USGS Publications Warehouse

    Siegel, D.C.; Congleton, J.L.

    1997-01-01

    Macrophages isolated from the anterior kidney of juvenile chinook salmon Oncorhynchus tshawytscha in 96-well microtiter plates were exposed for 72 h to 0, 105, or 106 live or heat-killed Renibacterium salmoninarum cells per well or to 0, 0.1, 1.0, or 10 ??g/mL of R. salmoninarum soluble proteins. After treatment, the bactericidal activity of the macrophages against Aerornonas salmonicida was determined by a colorimetric assay based on the reduction of the tetrazolium dye MTT to formazan by viable bacteria. The MTT assay was modified to allow estimation of the percentage of bacteria killed by reference to a standard curve relating the number of bacteria added to microtiter wells to absorbance by formazan at 600 nm. The live and heat-killed R. salmoninarum treatments significantly (P < 0.001) increased killing of A. salmonicida by chinook salmon macrophages. In each of the five trials, significantly (P < 0.05) greater increases in killing occurred after exposure to 105 R. salmoninarum cells than to 106 R. salmoninarum cells per well. In contrast, treatment of macrophages with 10 ??g/mL R. salmoninarum soluble proteins significantly (P < 0.001) decreased killing of A. salmonicida, but treatment with lower doses did not. These results show that the bactericidal activity of chinook salmon macrophages is stimulated by exposure to R. salmoninarum cells at lower dose levels but inhibited by exposure to R. salmoninarum cells or soluble proteins at higher dose levels.

  8. Toxicity of individual pharmaceuticals and their mixtures to Aliivibrio fischeri: Experimental results for single compounds and considerations of their mechanisms of action and potential acute effects on aquatic organisms.

    PubMed

    Di Nica, Valeria; Villa, Sara; Finizio, Antonio

    2017-03-01

    In the first part of a broader study on the effects of individual and multicomponent mixtures of pharmaceutical active compounds, the authors used the Microtox(®) test system to analyze in detail the effects of 10 widely used human and veterinary pharmaceutical active compounds toward the bioluminescent bacterium Aliivibrio fischeri. The experimental results indicated moderate toxicity for the majority of the tested compounds. Comparison between experimental 50% inhibitory concentrations and those predicted from the quantitative structure-activity relationship models indicated that most of the tested pharmaceutical active compounds behave as polar narcotic compounds toward A. fischeri (only the antibiotic chlortetracycline seemed to have a specific mechanism of action). A comparison between the experimental results and a collection of acute toxicity data on other nontarget organisms indicated that in general A. fischeri has a comparable sensitivity to other aquatic species. However, according to the Globally Harmonized System of Classification and Labelling of Chemicals, the majority of the investigated chemicals can be classified as harmful or nontoxic for aquatic ecosystems. Finally, based on comparisons among the 95th percentile of measured environmental concentrations found in European Union water bodies and acute toxicity data on various aquatic organisms, no risk to aquatic life exists when the tested pharmaceutical active compounds are assessed as individual chemicals. Environ Toxicol Chem 2017;36:807-814. © 2016 SETAC.

  9. Transcription Factor T-Bet in Atlantic Salmon: Characterization and Gene Expression in Mucosal Tissues during Aeromonas Salmonicida Infection

    PubMed Central

    Kumari, Jaya; Zhang, Zuobing; Swain, Trilochan; Chi, Heng; Niu, Cuijuan; Bøgwald, Jarl; Dalmo, Roy Ambli

    2015-01-01

    The T-box transcription factor T-bet is expressed in a number of hematopoietic cell types in mammals and plays an essential role in the lineage determination of Th1 T-helper cells and is considered as an essential feature for both innate and adaptive immune responses in higher vertebrates. In the present study, we have identified and characterized the full-length Atlantic salmon T-bet cDNA (3502 bp). The putative primary structure of the polypeptide deduced from the cDNA sequence contained 612 aa, which possessed a T-box DNA binding domain. Phylogenetic study and gene synteny revealed it is as a homolog to mammalian T-bet. Quantitative PCR analysis of different tissues in healthy fish showed that salmon T-bet gene was highly expressed in spleen, followed by head kidney, and was expressed in intestine, skin, and liver at lower levels. Moreover, the time-dependent expression profile of T-bet, interferon gamma (IFNγ), interleukin-22 (IL-22), and natural killer enhancement factor in mucosal tissues during water-borne infection with live Aeromonas salmonicida, indicated the involvement of T-bet in mucosal immune response in Atlantic salmon. PMID:26217339

  10. Transcription Factor T-Bet in Atlantic Salmon: Characterization and Gene Expression in Mucosal Tissues during Aeromonas Salmonicida Infection.

    PubMed

    Kumari, Jaya; Zhang, Zuobing; Swain, Trilochan; Chi, Heng; Niu, Cuijuan; Bøgwald, Jarl; Dalmo, Roy Ambli

    2015-01-01

    The T-box transcription factor T-bet is expressed in a number of hematopoietic cell types in mammals and plays an essential role in the lineage determination of Th1 T-helper cells and is considered as an essential feature for both innate and adaptive immune responses in higher vertebrates. In the present study, we have identified and characterized the full-length Atlantic salmon T-bet cDNA (3502 bp). The putative primary structure of the polypeptide deduced from the cDNA sequence contained 612 aa, which possessed a T-box DNA binding domain. Phylogenetic study and gene synteny revealed it is as a homolog to mammalian T-bet. Quantitative PCR analysis of different tissues in healthy fish showed that salmon T-bet gene was highly expressed in spleen, followed by head kidney, and was expressed in intestine, skin, and liver at lower levels. Moreover, the time-dependent expression profile of T-bet, interferon gamma (IFNγ), interleukin-22 (IL-22), and natural killer enhancement factor in mucosal tissues during water-borne infection with live Aeromonas salmonicida, indicated the involvement of T-bet in mucosal immune response in Atlantic salmon.

  11. Effect of dietary β-glucan on growth, survival and regulation of immune processes in rainbow trout (Oncorhynchus mykiss) infected by Aeromonas salmonicida.

    PubMed

    Ji, Liqin; Sun, Guoxiang; Li, Jun; Wang, Yi; Du, Yishuai; Li, Xian; Liu, Ying

    2017-05-01

    The present study evaluated the effects of dietary β-glucan (0, 0.05%, 0.1%, and 0.2%) on growth performance after 42 days of feeding. Thereafter, rainbow trout (Oncorhynchus mykiss) were infected with Aeromonas salmonicida, and survival rates as well as the regulating processes of stress- and immune-related factors were analyzed. In general, higher dietary β-glucan levels obviously improved specific growth rate (SGR), weight gain (WG) and feed efficiency (FE) (P ≤ 0.05). Survival rates in β-glucan groups increased significantly compared with the control group after A. salmonicida infection (P ≤ 0.05). Serum total superoxide dimutase (T-SOD), peroxidase (POD) as well as catalase (CAT) activities, and their mRNA expressions in the head kidney of fish in the β-glucan groups generally increased to higher levels after infection, and more quickly, compared with in the control group. Serum lysozyme (LSZ) and its expression in the head kidney in β-glucan groups reached a higher peak earlier than in the control group. Serum glutamic oxalacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) levels in the β-glucan groups were significantly lower than in the control group (P ≤ 0.05). The peak of heat shock protein 70 (HSP70) expression in the 0.2% β-glucan group was higher and occurred earlier than in other groups (P ≤ 0.05). These results confirm that 0.1% and 0.2% dietary β-glucan are beneficial for promoting growth in rainbow trout and enhancing resistance against A. salmonicida. Furthermore, β-glucan could play an important role in regulating stress- and immune-related factors in rainbow trout to more quickly fight against bacterial infection. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Effects of dietary linseed oil on innate immune system of Eurasian perch and disease resistance after exposure to Aeromonas salmonicida achromogen.

    PubMed

    Geay, F; Mellery, J; Tinti, E; Douxfils, J; Larondelle, Y; Mandiki, S N M; Kestemont, P

    2015-12-01

    This study was designated to investigate the effects of dietary fish oil (FO diet) replacement by linseed oil (LO diet) on regulation of immune response and disease resistance in Eurasian perch (Perca fluviatilis). A control diet containing fish oil (FO = cod liver oil) and characterized by high levels of n-3 high LC-PUFA (6% EPA, 7.5% of total fatty acids (FAs)) was compared to linseed oil diet (LO diet) composed of low LC-PUFA contents (1% EPA, 2.3% DHA of total FAs) but high C18 fatty acids levels. The experiment was conducted in quadruplicate groups of 80 fish each. After 10 weeks of feeding, the innate immune status was evaluated in various organs (liver, spleen, and head-kidney) (feeding condition). Two days later, a bacterial challenge was performed on fish from 2 rearing conditions: fish infected with Aeromonas salmonicida (bacteria condition) and fish injected with sterile medium but maintained in the same flow system that fish challenged with bacteria (sentinel condition). Three days after injection of bacteria, a significant decrease of lymphocyte, thrombocyte and basophil populations was observed while neutrophils were not affected. In addition, plasma lysozyme activity and reactive oxygen species production in kidney significantly increased in fish challenged with A. salmonicida while the plasma alternative complement pathway activity was not affected. Increase of plasma lysozyme activity as well as reactive oxygen species production in spleen and kidney of sentinel fish suggest that these immune defenses can also be activated, but at lower bacteria concentration than infected fish. No differences in leucocyte populations, plasma lysozyme and alternative complement pathway activities were observed between dietary treatments. Similarly, expression of genes related to eicosanoid synthesis in liver were not affected by the dietary oil source but were strongly stimulated in fish challenged with A. salmonicida. These findings demonstrated that the use of

  13. Antibody responses correlate with antigen dose and in vivo protection for oil-adjuvanted, experimental furunculosis (Aeromonas salmonicida subsp. salmonicida) vaccines in Atlantic salmon (Salmo salar L.) and can be used for batch potency testing of vaccines.

    PubMed

    Romstad, Anne Berit; Reitan, Liv Jorun; Midtlyng, Paul; Gravningen, Kjersti; Evensen, Øystein

    2013-01-21

    Salmon farming has increased dramatically over last thirty years and a key to the success is the introduction of protective vaccines. In Norway, almost 100% of all Atlantic salmon are vaccinated prior to sea transfer. This extensive use of vaccines demands use of a lot of resources in production and quality control of vaccines, and fish are now one of the most widely used laboratory animal species in Norway, since all batch testing today is performed by challenge experiments. With an increasing focus on the 3 R's (Replacement, Reduction and Refinement), new methods are needed. The aim of this study was to assess the use of different vaccine evaluation methods to identify furunculosis vaccines of different "potency", using ELISA as in vitro assay and intraperitoneal and cohabitation challenge as in vivo assays. Eleven vaccines with different antigen content (0, 2, 5, 10, 20, 40, 80, 100 and 200%) and different antigen qualities were included in the study. Challenge and blood sampling for the ELISA assay were conducted 9 weeks post vaccination. The results from this study indicated that there is a close correlation between the antigen dose in the vaccine and the antibody response against Aeromonas salmonicida as measured by ELISA. There is also a close correlation between the antibody response and protection for both i.p. and cohabitation challenge models. The ELISA method identified sub-potent batches better than currently used in vivo assay (i.p challenge) and seems to be the best method of performing a batch potency test of furunculosis vaccines particularly when taking the 3R's principles into account. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Detection of Aeromonas salmonicida, causal agent of furunculosis in salmonid fish, from the tank effluent of hatchery-reared Atlantic salmon smolts.

    PubMed Central

    O'Brien, D; Mooney, J; Ryan, D; Powell, E; Hiney, M; Smith, P R; Powell, R

    1994-01-01

    The fish pathogen, Aeromonas salmonicida, could be detected only by bacteriological culture from the kidney of dead or moribund fish in one tank in a hatchery rearing Atlantic salmon (Salmo salar L.) smolts. However, by using a DNA probe specific for this species, allied to a PCR assay, the pathogen could be detected in water, feces and effluent samples taken from this fish tank. Also, the presence of the pathogen was found in effluent samples from two fish tanks containing apparently healthy fish. Subsequently, the presence of pathogen in these tanks was confirmed by an increase in the daily mortality rate and by a plate culture from moribund fish. Images PMID:7527205

  15. Enhanced Aeromonas salmonicida bacterin uptake and side effects caused by low frequency sonophoresis in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Cobo, Cristóbal; Makosch, Katarzyna; Jung, Rainer; Kohlmann, Klaus; Knopf, Klaus

    2014-02-01

    Low frequency sonophoresis (LFS) has been recognized as one of the most advanced technologies in transdermal delivery of substances, due to the modification of the stratum corneum lipid bilayer, in focal skin applications in mammals. Based on these findings, LFS has been suggested as a potential technology to be used for enhancement in immersion fish vaccination. In contrast to mammals where LFS is applied to discrete regions of the skin, in fish the whole individual needs to be exposed for practical purposes. The current study evaluated the impact of LFS at 37 kHz on the uptake of an Aeromonas salmonicida bacterin and side effects of the treatment in rainbow trout. Quantitative real time PCR (qPCR) and immunohistochemistry were used to examine the bacterin uptake into skin and gill tissue. Side effects were assessed by behavioural examination, histology and blood serum analysis. The sonication intensity of 171 mW/cm² was enough for increasing skin permeability, but caused heavy erratic swimming and gill haemorrhages. Sonication intensities as low as 105 mW/cm² did not modify skin permeability and enhanced the bacterin uptake into the gill tissue by factor 15 compared to conventional immersion. Following sonication, the gill permeability for the bacterin decreased after 20 min and 120 min by factor 3 and 2, respectively. However, during sonication, erratic swimming of the fish raised some concerns. Further reduction of the sonication intensity to 57 mW/cm² did not induce erratic swimming, and the bacterin uptake into the gill tissue was still increased by factor 3. In addition, a decreasing albumin-globulin ratio in the serum of the rainbow trout within 40 min revealed that LFS leads to an inflammatory response. Consequently, based on both increased bacterin uptake and the inflammatory response, low intensity LFS has the potential to enhance vaccine immunity without significant side effects.

  16. Characterization of susceptibility and carrier status of burbot, Lota lota (L.), to IHNV, IPNV, Flavobacterium psychrophilum, Aeromonas salmonicida and Renibacterium salmoninarum.

    PubMed

    Polinski, M P; Fehringer, T R; Johnson, K A; Snekvik, K R; Lapatra, S E; Lafrentz, B R; Ireland, S C; Cain, K D

    2010-07-01

    In this study, susceptibility and potential carrier status of burbot, Lota lota, were assessed for five important fish pathogens. Burbot demonstrated susceptibility and elevated mortality following challenge with infectious haematopoietic necrosis virus (IHNV) by immersion and to Aeromonas salmonicida by intraperitoneal (i.p.) injection. IHNV persisted in fish for at least 28 days, whereas A. salmonicida was not re-isolated beyond 17 days post-challenge. In contrast, burbot appeared refractory to Flavobacterium psychrophilum following intramuscular (i.m.) injection and to infectious pancreatic necrosis virus (IPNV) by immersion. However, i.p injection of IPNV resulted in re-isolation of virus from fish for the duration of the 28 day challenge. Renibacterium salmoninarum appeared to induce an asymptomatic carrier state in burbot following i.p. injection, but overt manifestation of disease was not apparent. Viable bacteria persisted in fish for at least 41 days, and bacterial DNA isolated by diagnostic polymerase chain reaction was detected from burbot kidney tissue 90 days after initial exposure. This study is the first to investigate susceptibility of burbot to selected fish pathogens, and this information will aid in efforts to culture and manage this species.

  17. Efficacy of an extract from garlic, Allium sativum, against infection with the furunculosis bacterium, Aeromonas salmonicida, in rainbow trout, Oncorhynchus mykiss

    USGS Publications Warehouse

    Breyer, Kate E.; Getchell, Rodman G.; Cornwell, Emily R.; Wooster, Gregory A.; Ketola, H. George; Bowser, Paul R.

    2015-01-01

    Juvenile rainbow trout, Oncorhynchus mykiss, were fed diets containing 0, 0.5, 1.0, and 2.0% of a garlic extract, challenged with a modified 50% lethal dose of Aeromonas salmonicida and monitored for 28 d. There were significant increases in survival of trout fed 0.5 and 1.0% garlic extract as compared to the control and 2.0% garlic extract groups. A target animal safety study was performed at varying increments using the target dose of 0.5% garlic extract at 0× (0% garlic extract), 1× (0.5% garlic extract), 3× (1.5% garlic extract), and 5× (2.5% garlic extract) for 3× (6 wk) the duration of the original study. There was a significant increase in the level of circulating lymphocytes and a significant decrease in the level of circulating monocytes. The latter correlated to an increased level of pigment-containing macrophage centers within the renal tissue as garlic extract dosing increased, denoting a potential deleterious inflammatory effect as macrophage infiltration became severe at the highest dose. These studies suggest that feeding low-dose (0.5% or 1.0%) garlic extract improves survivability in rainbow trout when challenged with A. salmonicida and appears safe; however, higher levels do not appear to be effective and may cause deleterious effects on health.

  18. Toxoid construction of AsaP1, a lethal toxic aspzincin metalloendopeptidase of Aeromonas salmonicida subsp. achromogenes, and studies of its activity and processing.

    PubMed

    Schwenteit, Johanna; Bogdanović, Xenia; Fridjonsson, Olafur H; Aevarsson, Arnthor; Bornscheuer, Uwe T; Hinrichs, Winfried; Gudmundsdottir, Bjarnheidur K

    2013-03-23

    AsaP1 is a toxic aspzincin metalloendopeptidase secreted by the fish pathogen Aeromonas salmonicida subsp. achromogenes. The protease is highly immunogenic and antibodies against AsaP1 evoke a passive protection against infection with A. salmonicida subsp. achromogenes. The protease is expressed as 37 kDa pre-pro-protein and processed to an active enzyme of 19kDa in A. salmonicida subsp. achromogenes. Recombinant expression of AsaP1(rec) in E. coli results in a protease of 22 kDa that is not secreted. AsaP1(rec) induces comparable pathological changes in Atlantic salmon (Salmo salar L.) to native AsaP1(wt). The aim of the study was to construct AsaP1 toxoids by exchanging catalytically important amino acids in the active site region of the protease. Four different AsaP1 mutants (AsaP1(E294A), AsaP1(E294Q), AsaP1(Y309A), and AsaP1(Y309F)) were successfully constructed by one step site directed mutagenesis, expressed in E. coli BL21 C43 as pre-pro-proteins and purified by His-tag affinity chromatography and gel filtration. Three of the resulting mutants (AsaP1(E294A), AsaP1(E294Q), and AsaP1(Y309A)) were not caseinolytic active and are detected as unprocessed pre-pro-proteins of 37 kDa. Caseinolytic active AsaP1(rec) and a mutant with reduced activity, AsaP1(Y309F), were processed to a size of 22 kDa. Furthermore, AsaP1(rec) is able to process the inactive mutants to the mature size of 22 kDa, allowing the conclusion that AsaP1 is autocatalytically processed. All four mutants AsaP1(E294A), AsaP1(E294Q), AsaP1(Y309A) and AsaP1(Y309F) are non-toxic in fish but induce a specific anti-AsaP1 antibody response in Arctic charr (Salvelinus alpinus L.) and are therefore true toxoids and possible vaccine additives. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. The hydrocarbon-degrading marine bacterium Cobetia sp. strain MM1IDA2H-1 produces a biosurfactant that interferes with quorum sensing of fish pathogens by signal hijacking.

    PubMed

    Ibacache-Quiroga, C; Ojeda, J; Espinoza-Vergara, G; Olivero, P; Cuellar, M; Dinamarca, M A

    2013-07-01

    Biosurfactants are produced by hydrocarbon-degrading marine bacteria in response to the presence of water-insoluble hydrocarbons. This is believed to facilitate the uptake of hydrocarbons by bacteria. However, these diffusible amphiphilic surface-active molecules are involved in several other biological functions such as microbial competition and intra- or inter-species communication. We report the isolation and characterization of a marine bacterial strain identified as Cobetia sp. MM1IDA2H-1, which can grow using the sulfur-containing heterocyclic aromatic hydrocarbon dibenzothiophene (DBT). As with DBT, when the isolated strain is grown in the presence of a microbial competitor, it produces a biosurfactant. Because the obtained biosurfactant was formed by hydroxy fatty acids and extracellular lipidic structures were observed during bacterial growth, we investigated whether the biosurfactant at its critical micelle concentration can interfere with bacterial communication systems such as quorum sensing. We focused on Aeromonas salmonicida subsp. salmonicida, a fish pathogen whose virulence relies on quorum sensing signals. Using biosensors for quorum sensing based on Chromobacterium violaceum and Vibrio anguillarum, we showed that when the purified biosurfactant was mixed with N-acyl homoserine lactones produced by A. salmonicida, quorum sensing was inhibited, although bacterial growth was not affected. In addition, the transcriptional activities of A. salmonicida virulence genes that are controlled by quorum sensing were repressed by both the purified biosurfactant and the growth in the presence of Cobetia sp. MM1IDA2H-1. We propose that the biosurfactant, or the lipid structures interact with the N-acyl homoserine lactones, inhibiting their function. This could be used as a strategy to interfere with the quorum sensing systems of bacterial fish pathogens, which represents an attractive alternative to classical antimicrobial therapies in fish aquaculture.

  20. The hydrocarbon-degrading marine bacterium Cobetia sp. strain MM1IDA2H-1 produces a biosurfactant that interferes with quorum sensing of fish pathogens by signal hijacking

    PubMed Central

    Ibacache-Quiroga, C; Ojeda, J; Espinoza-Vergara, G; Olivero, P; Cuellar, M; Dinamarca, M A

    2013-01-01

    Summary Biosurfactants are produced by hydrocarbon-degrading marine bacteria in response to the presence of water-insoluble hydrocarbons. This is believed to facilitate the uptake of hydrocarbons by bacteria. However, these diffusible amphiphilic surface-active molecules are involved in several other biological functions such as microbial competition and intra-or inter-species communication. We report the isolation and characterization of a marine bacterial strain identified as Cobetia sp. MM1IDA2H-1, which can grow using the sulfur-containing heterocyclic aromatic hydrocarbon dibenzothiophene (DBT). As with DBT, when the isolated strain is grown in the presence of a microbial competitor, it produces a biosurfactant. Because the obtained biosurfactant was formed by hydroxy fatty acids and extracellular lipidic structures were observed during bacterial growth, we investigated whether the biosurfactant at its critical micelle concentration can interfere with bacterial communication systems such as quorum sensing. We focused on Aeromonas salmonicida subsp. salmonicida, a fish pathogen whose virulence relies on quorum sensing signals. Using biosensors for quorum sensing based on Chromobacterium violaceum and Vibrio anguillarum, we showed that when the purified biosurfactant was mixed with N-acyl homoserine lactones produced by A. salmonicida, quorum sensing was inhibited, although bacterial growth was not affected. In addition, the transcriptional activities of A. salmonicida virulence genes that are controlled by quorum sensing were repressed by both the purified biosurfactant and the growth in the presence of Cobetia sp. MM1IDA2H-1. We propose that the biosurfactant, or the lipid structures interact with the N-acyl homoserine lactones, inhibiting their function. This could be used as a strategy to interfere with the quorum sensing systems of bacterial fish pathogens, which represents an attractive alternative to classical antimicrobial therapies in fish

  1. A genomic survey of the fish parasite Spironucleus salmonicida indicates genomic plasticity among diplomonads and significant lateral gene transfer in eukaryote genome evolution

    PubMed Central

    Andersson, Jan O; Sjögren, Åsa M; Horner, David S; Murphy, Colleen A; Dyal, Patricia L; Svärd, Staffan G; Logsdon, John M; Ragan, Mark A; Hirt, Robert P; Roger, Andrew J

    2007-01-01

    Background Comparative genomic studies of the mitochondrion-lacking protist group Diplomonadida (diplomonads) has been lacking, although Giardia lamblia has been intensively studied. We have performed a sequence survey project resulting in 2341 expressed sequence tags (EST) corresponding to 853 unique clones, 5275 genome survey sequences (GSS), and eleven finished contigs from the diplomonad fish parasite Spironucleus salmonicida (previously described as S. barkhanus). Results The analyses revealed a compact genome with few, if any, introns and very short 3' untranslated regions. Strikingly different patterns of codon usage were observed in genes corresponding to frequently sampled ESTs versus genes poorly sampled, indicating that translational selection is influencing the codon usage of highly expressed genes. Rigorous phylogenomic analyses identified 84 genes – mostly encoding metabolic proteins – that have been acquired by diplomonads or their relatively close ancestors via lateral gene transfer (LGT). Although most acquisitions were from prokaryotes, more than a dozen represent likely transfers of genes between eukaryotic lineages. Many genes that provide novel insights into the genetic basis of the biology and pathogenicity of this parasitic protist were identified including 149 that putatively encode variant-surface cysteine-rich proteins which are candidate virulence factors. A number of genomic properties that distinguish S. salmonicida from its human parasitic relative G. lamblia were identified such as nineteen putative lineage-specific gene acquisitions, distinct mutational biases and codon usage and distinct polyadenylation signals. Conclusion Our results highlight the power of comparative genomic studies to yield insights into the biology of parasitic protists and the evolution of their genomes, and suggest that genetic exchange between distantly-related protist lineages may be occurring at an appreciable rate in eukaryote genome evolution. PMID

  2. Transcriptional changes in innate immunity genes in head kidneys from Aeromonas salmonicida-challenged rainbow trout fed a mixture of polycyclic aromatic hydrocarbons.

    PubMed

    Curtis, Lawrence R; Bravo, Claudia F; Bayne, Christopher J; Tilton, Fred; Arkoosh, Mary R; Lambertini, Elisabetta; Loge, Frank J; Collier, Tracy K; Meador, James P; Tilton, Susan C

    2017-08-01

    We previously observed that exposure to a complex mixture of high molecular weight polycyclic aromatic hydrocarbons (PAHs) increased sensitivity of rainbow trout (Oncorhynchus mykiss) to subsequent challenge with Aeromonas salmonicida, the causative agent of furunculosis. In this study, we evaluate potential mechanisms associated with disease susceptibility from combined environmental factors of dietary PAH exposure and pathogen challenge. Rainbow trout were fed a mixture of ten high molecular weight PAHs at an environmentally relevant concentration (7.82μg PAH mixture/g fish/day) or control diet for 50 days. After 50 days of PAH exposure, fish were challenged with either Aeromonas salmonicida at a lethal concentration 30 (LC30) or growth media without the pathogen (mock challenge). Head kidneys were collected 2, 4, 10 and 20 days after challenge and gene expression (q<0.05) was evaluated among treatments. In animals fed the PAH contaminated diet, we observed down-regulation of expression for innate immune system genes in pathways (p<0.05) for the terminal steps of the complement cascade (complement component C6) and other bacteriolytic processes (lysozyme type II) potentially underlying increased disease susceptibility after pathogen challenge. Increased expression of genes associated with hemorrhage/tissue remodeling/inflammation pathways (p<0.05) was likely related to more severe head kidney damage due to infection in PAH-fed compared to control-fed fish. This study is the first to evaluate transcriptional signatures associated with the impact of chronic exposure to an environmentally relevant mixture of PAHs in disease susceptibility and immunity. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Lipopolysaccharides isolated from Aeromonas salmonicida and Vibrio anguillarum show quantitative but not qualitative differences in inflammatory outcome in Sparus aurata (Gilthead seabream).

    PubMed

    Boltaña, S; Tridico, R; Teles, M; Mackenzie, S; Tort, L

    2014-08-01

    In fish, the defence system recognises pathogenic microorganisms via pathogen recognition receptors (PRRs) that sense particular structures of the pathogens; the so-called pathogen associated molecular patterns (PAMPs) such as bacterial lipopolysaccharides (LPSs). The result of the PAMP-PRR interactions leads to complex and orchestrated immune responses. In this study, Sparus aurata (Gilthead seabream) were intraperitoneally injected with purified lipopolysaccharide (LPS) from Aeromonas salmonicida (As)- and Vibrio anguillarum (Va) (1 mg*Kgfish(-1)), both Gram negative bacteria responsible for vibriosis and furunculosis respectively, therefore causing an impact upon marine fish cultures. Head-kidney, intestine, spleen, liver and blood samples were collected at 3, 6, 12 and 24 h post-injection. Plasma levels of cortisol, prostaglandins and lactate were measured and were significantly increased after As-LPS and Va-LPS treatment. Furthermore, tissue-specific differences of the gene regulatory patterns were evident for each LPS. When monocyte/macrophage cell cultures were challenged with As-LPS and Va-LPS, the pro-inflammatory cytokine mRNA abundances present a similar pattern of response. However, As-LPS always triggered a stronger response concerning TNFα, IL1β and cyclooxygenase-2 (COX2) mRNA abundance as well as PGE2 levels in the supernatant. Overall, the results indicate that specific LPSs do not activate different pro-inflammatory responses and that the observed gene expression pattern is tissue and concentration dependent.

  4. Use of human cDNA microarrays for identification of differentially expressed genes in Atlantic salmon liver during Aeromonas salmonicida infection.

    PubMed

    Tsoi, Stephen C M; Cale, Jacqueline M; Bird, Ian M; Ewart, Vanya; Brown, Laura L; Douglas, Susan

    2003-01-01

    Commercially available human complementary DNA microarrays were used to compare differential expression in the livers of Atlantic salmon ( Salmo salar) infected with Aeromonas salmonicida and of healthy fish. Complementary DNA probes were prepared from total RNA isolated from livers of control salmon and infected salmon by reverse transcription in the presence of (33)P-dCTP and independently hybridized to human GENE-FILTERS GF211 microarrays. Of the 4131 known genes on the microarray, 241 spots gave clearly detectable signals using labeled RNA from the control salmon liver. Of these, 4 spots were consistently found to have a greater than 2-fold increase in infected salmon compared with controls when using the same pair of filters to generate hybridization data from triplicates. These up-regulated genes were ADP/ATP translocase (AAT2), Na(+)/K(+) ATPase, acyloxyacyl hydrolase (AOAH), and platelet-derived growth factor (PDFG-A). A BlastN search revealed an AAT2 homolog from Atlantic salmon, and a reverse transcriptase polymerase chain reaction assay using primers based on this sequence confirmed its up-regulation (approx. 1.8-fold) during early infection. This work demonstrates the feasibility of using human microarrays to facilitate the discovery of differentially expressed genes in Atlantic salmon, for which no homologous microarrays are available.

  5. Identification of differentially expressed protective genes in liver of two rainbow trout strains.

    PubMed

    Rebl, Alexander; Verleih, Marieke; Korytář, Thomáš; Kühn, Carsten; Wimmers, Klaus; Köllner, Bernd; Goldammer, Tom

    2012-01-15

    Since 1975, the rainbow trout strain BORN (Germany) has been bred in brackish water from a coastal form imported from Denmark. Accompanying phenotypic monitoring of the adapted BORN trout until now revealed that this selection strain manifested a generally elevated resistance towards high stress and pathogenic challenge including lower susceptibility towards Aeromonas salmonicida infections in comparison to other trout strains in local aqua farms. We focus on the elucidation of both, genetic background and immunological basis for the increased survivorship to infections. A first comparison of gene expression profiles in liver tissue of healthy rainbow trout from the local selection strain BORN and imported trout using a GRASP 16K cDNA microarray revealed six differentially expressed genes evoking pathogen and wounding responses, LEAP2A (encoding for liver-expressed antimicrobial peptide), SERPINA1 (alpha-1 antitrypsin), FTH1 (middle subunit of ferritin), FGL2 (fibroleukin), CLEC4E (macrophage-inducible C-type lectin), and SERPINF2 (alpha-2 antiplasmin). Since the latter gene is not described in salmonid species so far, our first aim was to characterize the respective sequence in rainbow trout. Two trout SERPINF2 genes were identified, which share only 48% identical amino acid residues and a characteristic SERPIN domain. Second, we aimed to analyse the expression of those genes after temperature challenge (8 °C and 23 °C). Only FTH1 was upregulated in BORN and import trout after increase of temperature, while SERPINA1 and FGL2 were only elevated in import trout. Third, the expression of all named genes was analyzed after pathogen challenge with A. salmonicida subsp. salmonicida. As a main finding, we detected a comparably faster regeneration of LEAP2A mRNA abundance in BORN trout following bacterial infection. Ingenuity Pathways Analysis suggested a functional interplay among the mentioned factors and the pro-inflammatory cytokine TNF, whose stronger expression

  6. Steelhead trout Oncorhynchus mykiss metabolic rate is affected by dietary Aloe vera inclusion but not by mounting an immune response against formalin-killed Aeromonas salmonicida.

    PubMed

    Zanuzzo, F S; Urbinati, E C; Nash, G W; Gamperl, A K

    2015-07-01

    The oxygen consumption (MO2) of two groups of 10° C acclimated steelhead trout Oncorhynchus mykiss was measured for 72 h after they were given a 100 µl kg(-1) intraperitoneal injection of formalin-killed Aeromonas salmonicida (ASAL) or phosphate-buffered saline (PBS). In addition, plasma cortisol levels were measured in fish from both groups prior to, and 1 and 3 h after, they were given a 30 s net stress. The first group was fed an unaltered commercial diet for 4 weeks, whereas the second group was fed the same diet but with 0·5% (5 g kg(-1) ) Aloe vera powder added; A. vera has potential as an immunostimulant for use in aquaculture, but its effects on basal and acute phase response (APR)-related metabolic expenditures and stress physiology, are unknown. Injection of ASAL v. PBS had no measurable effect on the MO2 of O. mykiss indicating that the APR in this species is not associated with any net increase in energy expenditure. In contrast, incorporating 0·5% A. vera powder into the feed decreased routine metabolic rate by c. 8% in both injection groups and standard metabolic rate in the ASAL-injected group (by c. 4 mg O2 kg(-1) h(-1) ; 5%). Aloe vera fed fish had resting cortisol levels that were approximately half of those in fish on the commercial diet (c. 2·5 v. 5·0 ng ml(-1) ), but neither this difference nor those post-stress reached statistical significance (P > 0·05). © 2015 The Fisheries Society of the British Isles.

  7. Distribution and retention of antigens of Aeromonas salmonicida in Atlantic salmon (Salmo salar L.) vaccinated with a DeltaaroA mutant or formalin-inactivated bacteria in oil-adjuvant.

    PubMed

    Grove, S; Høie, S; Evensen, Ø

    2003-10-01

    In this study we report the differences in distribution and retention of Aeromonas salmonicida antigens after vaccination with two different vaccines. Parr of Atlantic salmon (Salmo salar) were given intraperitoneal injections of either a commercial, monovalent furunculosis vaccine (Apoject) or live, attenuated A. salmonicida (DeltaaroA). Fish were sampled at weeks 2, 4 and 12 post-vaccination and head kidney and spleen were collected. Presence of LPS and 16S rDNA in isolated leukocytes were investigated by immunocytochemistry and polymerase chain reaction (PCR).16S rDNA was detected in head kidney and spleen of all DeltaaroA vaccinated and most Apoject-vaccinated fish at weeks 2 and 4. At week 12, 16S rDNA was detected in none of the DeltaaroA vaccinated fish, but it was detected in head kidney of 75% of Apoject-vaccinated fish. LPS was detected in both vaccination groups at all sampling times, but most frequently in the DeltaaroA vaccinated fish (in head kidney 75-83% vs. 50%, in spleen 58-67% vs. 17-25%).

  8. Biodegradation and detoxification of olive mill wastewater by selected strains of the mushroom genera Ganoderma and Pleurotus.

    PubMed

    Ntougias, Spyridon; Baldrian, Petr; Ehaliotis, Constantinos; Nerud, Frantisek; Antoniou, Theodoros; Merhautová, Věra; Zervakis, Georgios I

    2012-07-01

    Thirty-nine white-rot fungi belonging to nine species of Agaricomycotina (Basidiomycota) were initially screened for their ability to decrease olive-mill wastewater (OMW) phenolics. Four strains of Ganoderma australe, Ganoderma carnosum, Pleurotus eryngii and Pleurotus ostreatus, were selected and further examined for key-aspects of the OMW biodegradation process. Fungal growth in OMW-containing batch cultures resulted in significant decolorization (by 40-46% and 60-65% for Ganoderma and Pleurotus spp. respectively) and reduction of phenolics (by 64-67% and 74-81% for Ganoderma and Pleurotus spp. respectively). COD decrease was less pronounced (12-29%). Cress-seeds germination increased by 30-40% when OMW was treated by Pleurotus strains. Toxicity expressed as inhibition of Aliivibrio fischeri luminescence was reduced in fungal-treated OMW samples by approximately 5-15 times compared to the control. As regards the pertinent enzyme activities, laccase and Mn-independent peroxidase were detected for Ganoderma spp. during the entire incubation period. In contrast, Pleurotus spp. did not exhibit any enzyme activities at early growth stages; instead, high laccase (five times greater than those of Ganoderma spp.) and Mn peroxidases activities were determined at the end of treatment. OMW decolorization by Ganoderma strains was strongly correlated to the reduction of phenolics, whereas P. eryngii laccase activity was correlated with the effluent's decolorization.

  9. Quorum sensing in Aeromonas hydrophila and Aeromonas salmonicida: identification of the LuxRI homologs AhyRI and AsaRI and their cognate N-acylhomoserine lactone signal molecules.

    PubMed Central

    Swift, S; Karlyshev, A V; Fish, L; Durant, E L; Winson, M K; Chhabra, S R; Williams, P; Macintyre, S; Stewart, G S

    1997-01-01

    Spent culture supernatants from both Aeromonas hydrophila and Aeromonas salmonicida activate a range of biosensors responsive to N-acylhomoserine lactones (AHLs). The genes for a quorum sensing signal generator and a response regulator were cloned from each Aeromonas species and termed ahyRI and asaRI, respectively. Protein sequence homology analysis places the gene products within the growing family of LuxRI homologs. ahyR and asaR are transcribed divergently from ahyI and asaI, respectively, and in both Aeromonas species, the genes downstream have been identified by DNA sequence and PCR analysis. Downstream of both ahyI and asaI is a gene with close homology to iciA, an inhibitor of chromosome replication in Escherichia coli, a finding which implies that in Aeromonas, cell division may be linked to quorum sensing. The major signal molecule synthesized via both AhyI and AsaI was purified from spent culture supernatants and identified as N-(butanoyl)-L-homoserine lactone (BHL) by thin-layer chromatography, high-pressure liquid chromatography analysis, and mass spectrometry. In addition, a second, minor AHL, N-hexanoyl-L-homoserine lactone, was identified. Transcriptional reporter studies with ahyI::luxCDABE fusions indicate that AhyR and BHL are both required for ahyI transcription. For A. salmonicida, although the addition of exogenous BHL gives only a small stimulation of the production of serine protease with comparison to the control culture, the incorporation of a longer-chain AHL, N-(3-oxodecanoyl)-L-homoserine lactone, reduced the final level (by approximately 50%) and delayed the appearance (from an A650 of 0.9 in the control to an A650 of 1.2 in the test) of protease in the culture supernatant. These data add A. hydrophila and A. salmonicida to the growing family of gram-negative bacteria now known to control gene expression through quorum sensing. PMID:9286976

  10. Natural Strain

    NASA Technical Reports Server (NTRS)

    Freed, Alan D.

    1995-01-01

    The purpose of this paper is to present a consistent and thorough development of the strain and strain-rate measures affiliated with Hencky. Natural measures for strain and strain-rate, as I refer to them, are first expressed in terms of of the fundamental body-metric tensors of Lodge. These strain and strain-rate measures are mixed tensor fields. They are mapped from the body to space in both the Eulerian and Lagrangian configurations, and then transformed from general to Cartesian fields. There they are compared with the various strain and strain-rate measures found in the literature. A simple Cartesian description for Hencky strain-rate in the Lagrangian state is obtained.

  11. Strain Gage

    NASA Technical Reports Server (NTRS)

    1995-01-01

    HITEC Corporation developed a strain gage application for DanteII, a mobile robot developed for NASA. The gage measured bending forces on the robot's legs and warned human controllers when acceptable forces were exceeded. HITEC further developed the technology for strain gage services in creating transducers out of "Indy" racing car suspension pushrods, NASCAR suspension components and components used in motion control.

  12. Experimental Identification of Actinobacillus pleuropneumoniae Strains L20 and JL03 Heptosyltransferases, Evidence for a New Heptosyltransferase Signature Sequence

    PubMed Central

    Merino, Susana; Knirel, Yuriy A.; Regué, Miguel; Tomás, Juan M.

    2013-01-01

    We experimentally identified the activities of six predicted heptosyltransferases in Actinobacillus pleuropneumoniae genome serotype 5b strain L20 and serotype 3 strain JL03. The initial identification was based on a bioinformatic analysis of the amino acid similarity between these putative heptosyltrasferases with others of known function from enteric bacteria and Aeromonas. The putative functions of all the Actinobacillus pleuropneumoniae heptosyltrasferases were determined by using surrogate LPS acceptor molecules from well-defined A. hydrophyla AH-3 and A. salmonicida A450 mutants. Our results show that heptosyltransferases APL_0981 and APJL_1001 are responsible for the transfer of the terminal outer core D-glycero-D-manno-heptose (D,D-Hep) residue although they are not currently included in the CAZY glycosyltransferase 9 family. The WahF heptosyltransferase group signature sequence [S(T/S)(GA)XXH] differs from the heptosyltransferases consensus signature sequence [D(TS)(GA)XXH], because of the substitution of D261 for S261, being unique. PMID:23383222

  13. Hip flexor strain - aftercare

    MedlinePlus

    ... flexor - aftercare; Hip flexor injury - aftercare; Hip flexor tear - aftercare; Iliopsoas strain - aftercare; Strained iliopsoas muscle - aftercare; Torn iliopsoas muscle - aftercare; Psoas strain - aftercare

  14. High temperature strain gage apparent strain compensation

    NASA Technical Reports Server (NTRS)

    Holmes, Harlan K.; Moore, T. C., Sr.

    1992-01-01

    Once an installed strain gage is connected to a strain indicating device and the instrument is balanced, a subsequent change in temperature of the gage installation will generally produce a resistance change in the gage. This purely temperature-induced resistance will be registered by the indicating device as a strain and is referred to as 'apparent strain' to distinguish it from strain due to applied stress. One desirable technique for apparent strain compensation is to employ two identical gages with identical mounting procedures which are connected with a 'half bridge' configuration where gages see the same thermal environment but only one experiences a mechanical strain input. Their connection in adjacent arms of the bridge will then balance the thermally induced apparent strains and, in principle, only the mechanical strain remains. Two approaches that implement this technique are discussed.

  15. Geobacteraceae strains and methods

    DOEpatents

    Lovley, Derek R.; Nevin, Kelly P.; Yi, Hana

    2015-07-07

    Embodiments of the present invention provide a method of producing genetically modified strains of electricigenic microbes that are specifically adapted for the production of electrical current in microbial fuel cells, as well as strains produced by such methods and fuel cells using such strains. In preferred embodiments, the present invention provides genetically modified strains of Geobacter sulfurreducens and methods of using such strains.

  16. Improving survival and storage stability of bacteria recalcitrant to freeze-drying: a coordinated study by European culture collections.

    PubMed

    Peiren, Jindrich; Buyse, Joke; De Vos, Paul; Lang, Elke; Clermont, Dominique; Hamon, Sylviane; Bégaud, Evelyne; Bizet, Chantal; Pascual, Javier; Ruvira, María A; Macián, M Carmen; Arahal, David R

    2015-04-01

    The objective of this study is to improve the viability after freeze-drying and during storage of delicate or recalcitrant strains safeguarded at biological resource centers. To achieve this objective, a joint experimental strategy was established among the different involved partner collections of the EMbaRC project ( www.embarc.eu ). Five bacterial strains considered as recalcitrant to freeze-drying were subjected to a standardized freeze-drying protocol and to seven agreed protocol variants. Viability of these strains was determined before and after freeze-drying (within 1 week, after 6 and 12 months, and after accelerated storage) for each of the protocols. Furthermore, strains were exchanged between partners to perform experiments with different freeze-dryer-dependent parameters. Of all tested variables, choice of the lyoprotectant had the biggest impact on viability after freeze-drying and during storage. For nearly all tested strains, skim milk as lyoprotectant resulted in lowest viability after freeze-drying and storage. On the other hand, best freeze-drying and storage conditions were strain and device dependent. For Aeromonas salmonicida CECT 894(T), best survival was obtained when horse serum supplemented with trehalose was used as lyoprotectant, while Aliivibrio fischeri LMG 4414(T) should be freeze-dried in skim milk supplemented with marine broth in a 1:1 ratio. Freeze-drying Campylobacter fetus CIP 53.96(T) using skim milk supplemented with trehalose as lyoprotectant resulted in best recovery. Xanthomonas fragariae DSM 3587(T) expressed high viability after freeze-drying and storage for all tested lyoprotectants and could not be considered as recalcitrant. In contrary, Flavobacterium columnare LMG 10406(T) did not survive the freeze-drying process under all tested conditions.

  17. Muscle strain treatment

    MedlinePlus

    Treatment - muscle strain ... Question: How do you treat a muscle strain ? Answer: Rest the strained muscle and apply ice for the first few days after the injury. Anti-inflammatory medicines or acetaminophen ( ...

  18. Muscle strain (image)

    MedlinePlus

    A muscle strain is the stretching or tearing of muscle fibers. A muscle strain can be caused by sports, exercise, a ... something that is too heavy. Symptoms of a muscle strain include pain, tightness, swelling, tenderness, and the ...

  19. Characteristics of bacterial strains inhabiting the wood of coniferous trees.

    PubMed

    Gajewska, Julitta; Miszczyk, Anita; Markiewicz, Zdzisław

    2004-01-01

    The presented studies embraced samples of wood chips from coniferous trees which contained layers of duramen, alburnum and bark. Microbiological analysis involved qualitative and quantitative determination of bacterial flora inhabiting the studied wood material. The wood chips were found to contain primarily species belonging to the genera Bacillus and Pseudomonas. The presence of the potentially pathogenic species Bacillus cereus 1, Sphingomonas paucimobilis, Aeromonas salmonicida and Chryseomonas luteola was also demonstrated.

  20. Superlattice strain gage

    DOEpatents

    Noel, Bruce W.; Smith, Darryl L.; Sinha, Dipen N.

    1990-01-01

    A strain gage comprising a strained-layer superlattice crystal exhibiting piezoelectric properties is described. A substrate upon which such a strained-layer superlattice crystal has been deposited is attached to an element to be monitored for strain. A light source is focused on the superlattice crystal and the light reflected from, passed through, or emitted from the crystal is gathered and compared with previously obtained optical property data to determine the strain in the element.

  1. Superlattice strain gage

    DOEpatents

    Noel, B.W.; Smith, D.L.; Sinha, D.N.

    1988-06-28

    A strain gage comprising a strained-layer superlattice crystal exhibiting piezoelectric properties is described. A substrate upon which such a strained-layer superlattice crystal has been deposited is attached to an element to be monitored for strain. A light source is focused on the superlattice crystal and the light reflected from, passed through, or emitted from the crystal is gathered and compared with previously obtained optical property data to determine the strain in the element. 8 figs.

  2. A balloon strain gage

    NASA Technical Reports Server (NTRS)

    Rand, J. L.

    1981-01-01

    This paper describes the development of a unique strain measuring device which is intended to monitor the state of strain in thin balloon films during flight. The gate is bonded directly to the film without significantly altering the state of strain or stress in the wall of the balloon. Results of a model balloon inflation are presented which indicate the gage to measure strain in a deployed balloon.

  3. Balloon film strain measurement

    NASA Technical Reports Server (NTRS)

    Rand, J. L.

    1983-01-01

    A discussion is presented of the results of a flight test program in which scientific research balloon material strain was measured in order to determine stress levels. Attention is given to material strain characteristics during the inflation, launch, ascent, and flight of a natural shape, zero-pressure scientific balloon. Measurements were conducted with a simple thin film strain transducer. Thermal, meridional and circumferential strain history data for the test flight are given.

  4. Elevated temperature strain gages

    NASA Technical Reports Server (NTRS)

    Brittain, J. O.; Geslin, D.; Lei, J. F.

    1985-01-01

    Materials were evaluated that could be used in manufacturing electrical resistance strain gages for static strain measurements at temperatures at or above 1273 K. Strain gage materials must have a characteristic response to strain, temperature and time that is reproducible or that varies in a predictable manner within specified limits. Several metallic alloys were evaluated, as well as a series of transition metal carbides, nitrides and silicides.

  5. Sprains and Strains

    MedlinePlus

    ... happens. A strain is a stretched or torn muscle or tendon. Tendons are tissues that connect muscle to bone. Twisting or pulling these tissues can ... suddenly or develop over time. Back and hamstring muscle strains are common. Many people get strains playing ...

  6. Strain powered antennas

    NASA Astrophysics Data System (ADS)

    Domann, John P.; Carman, Greg P.

    2017-01-01

    This paper proposes the creation of strain powered antennas that radiate electromagnetic energy by mechanically vibrating a piezoelectric or piezomagnetic material. A closed form analytic model of electromagnetic radiation from a strain powered electrically small antenna is derived and analyzed. Fundamental scaling laws and the frequency dependence of strain powered antennas are discussed. The radiation efficiency of strain powered electrically small antennas is contrasted with a conventional electric dipole. Analytical results show that operating at the first mechanical resonance produces the most efficient strain powered radiation relative to electric dipole antennas. A resonant analysis is exploited to determine the material property space that produces efficient strain powered antennas. These results show how a properly designed strain powered antenna can radiate more efficiently than an equally sized electric dipole antenna.

  7. Three dimensional strained semiconductors

    DOEpatents

    Voss, Lars; Conway, Adam; Nikolic, Rebecca J.; Leao, Cedric Rocha; Shao, Qinghui

    2016-11-08

    In one embodiment, an apparatus includes a three dimensional structure comprising a semiconductor material, and at least one thin film in contact with at least one exterior surface of the three dimensional structure for inducing a strain in the structure, the thin film being characterized as providing at least one of: an induced strain of at least 0.05%, and an induced strain in at least 5% of a volume of the three dimensional structure. In another embodiment, a method includes forming a three dimensional structure comprising a semiconductor material, and depositing at least one thin film on at least one surface of the three dimensional structure for inducing a strain in the structure, the thin film being characterized as providing at least one of: an induced strain of at least 0.05%, and an induced strain in at least 5% of a volume of the structure.

  8. Strain sensor comprising a strain sensitive, two-mode optical

    NASA Technical Reports Server (NTRS)

    Egalon, Claudio Oliveira (Inventor); Rogowski, Robert S. (Inventor)

    1994-01-01

    A strain sensor uses an optical fiber including a strain sensitive portion and at least one strain insensitive portion. The strain sensitive portion is mounted on the surface of a structure at a location where a strain is desired to be measured. The strain insensitive portion(s) may be fused to the strain sensitive portion to transmit light therethrough, so that the resulting pattern may be detected to determine the amount of strain by comparison with a similar fiber not subjected to strain, or with the light pattern produced when the fiber is not under strain.

  9. Thin film strain transducer

    NASA Technical Reports Server (NTRS)

    Rand, J. L. (Inventor)

    1984-01-01

    A strain transducer system and process for making the same is disclosed. A beryllium copper ring having four strain gages is electrically connected in Wheatstone bridge fashion to the output instrumentation. Tabs are bonded to a balloon or like surface with strain on the surface causing bending of a ring which provides an electrical signal through the gages proportional to the surface strain. A photographic pattern of a one half ring segment as placed on a sheet of beryllium copper for chem-mill etch formation is illustrated.

  10. Strained Silicon Photonics

    PubMed Central

    Schriever, Clemens; Bohley, Christian; Schilling, Jörg; Wehrspohn, Ralf B.

    2012-01-01

    A review of recent progress in the field of strained silicon photonics is presented. The application of strain to waveguide and photonic crystal structures can be used to alter the linear and nonlinear optical properties of these devices. Here, methods for the fabrication of strained devices are summarized and recent examples of linear and nonlinear optical devices are discussed. Furthermore, the relation between strain and the enhancement of the second order nonlinear susceptibility is investigated, which may enable the construction of optically active photonic devices made of silicon. PMID:28817015

  11. Light intensity strain analysis

    NASA Technical Reports Server (NTRS)

    Williams, J. G. (Inventor)

    1973-01-01

    A process is described for the analysis of the strain field of structures subjected to large deformations involving a low modulus substrate having a high modulus, relatively thin coating. The optical properties of transmittance and reflectance are measured for the coated substrate while stressed and unstressed to indicate the strain field for the coated substrate.

  12. Mechanical strain isolator mount

    NASA Technical Reports Server (NTRS)

    James, Gordon E. (Inventor)

    1991-01-01

    Certain devices such as optical instruments must preserve their alignmental integrity while being subjected to mechanical strain. A mechanical strain isolator mount is provided to preserve the alignmental integrity of an alignment sensitive instrument. An alignment sensitive instrument is mounted on a rectangular base. Flexural legs are connected at their proximal ends to the rectangular base. Flexural legs are also spaced parallel to the sides. Mounting pads are connected to the legs at the distal end and the mechanical strain isolator mount is attached to the substrate by means of threaded bolts. When a mounting pad and its respective leg is subjected to lateral strain in either the X or Y direction via the substrate, the respective leg relieves the strain by bending in the direction of the strain. An axial strain on a mounting pad in the Z direction is relieved by a rotational motion of the legs in the direction of the strain. When the substrate is stress free, the flexural legs return to their original condition and thus preserve the original alignment integrity of the alignment sensitive instrument.

  13. Chitinase producing Bt strains

    Treesearch

    Haim B. Gunner; Matthew Zimet; Sarah Berger

    1985-01-01

    Screening of 402 strains of more than 18 varieties of Bacillus thuringiensis showed chitinase to be inducible in virtually every serovar tested. Though the chitinase titre varied among strains, there was a strong correlation between enhanced lethality to spruce budworm, Choristoneura fumiferana (Clemens), and an increase in...

  14. Hamstring strain - aftercare

    MedlinePlus

    ... mild muscle strain or pull Grade 2 -- partial muscle tear Grade 3 -- complete muscle tear Recovery time depends on the grade of the ... be healing as expected. Alternative Names Pulled hamstring muscle; Sprain - ... Ali K, Leland JM. Hamstring strains and tears in the athlete. Clin Sports Med . 2012;31( ...

  15. Heat strain in cold.

    PubMed

    Rintamäki, Hannu; Rissanen, Sirkka

    2006-07-01

    In spite of increased environmental cold stress, heat strain is possible also in a cold environment. The body heat balance depends on three factors: environmental thermal conditions, metabolic heat production and thermal insulation of clothing and other protective garments. As physical exercise may increase metabolic heat production from rest values by ten times or even more, the required thermal insulation of clothing may vary accordingly. However, in most outdoor work, and often in indoor cold work, too, the thermal insulation of clothing is impractical, difficult or impossible to adjust according to the changes in physical activity. This is especially true with whole body covering garments like chemical protective clothing. As a result of this imbalance, heat strain may develop. In cold all the signs of heat strain (core temperature above 38 degrees C, warm or hot thermal sensations, increased cutaneous circulation and sweating) may not be present at the same time. Heat strain in cold may be whole body heat strain or related only to torso or core temperature. Together with heat strain in torso or body core, there can be at the same time even cold strain in peripheral parts and/or superficial layers of the body. In cold environment both the preservation of insulation and facilitation of heat loss are important. Development of clothing design is still needed to allow easy adjustments of thermal insulation.

  16. Thin film strain transducer

    NASA Astrophysics Data System (ADS)

    Rand, J. L.

    1981-01-01

    Previous attempts to develop an appropriate sensor for measuring the stress or strain of high altitude balloons during flight are reviewed as well as the various conditions that must be met by such a device. The design, development and calibration of a transducer which promises to satisfy the necessary design constraints are described. The thin film strain transducer has a low effective modulus so as not to interfere with the strain that would naturally occur in the balloon. In addition, the transducer has a high sensitivity to longitudinal strain (7.216 mV/V/unit strain) which is constant for all temperature from room temperature to -80 C and all strains from 5 percent compression to 10 percent tensile strain. At the same time, the sensor is relatively insensitive (0.27 percent) to transverse forces. The device has a standard 350 ohm impedance which is compatible with available bridge balance, amplification and telemetry instrumentation now available for balloon flight. Recommendations are included for improved coatings to provide passive thermal control as well as model, tethered and full scale flight testing.

  17. Strain gauge installation tool

    DOEpatents

    Conard, Lisa Marie

    1998-01-01

    A tool and a method for attaching a strain gauge to a test specimen by maaining alignment of, and applying pressure to, the strain gauge during the bonding of the gauge to the specimen. The tool comprises rigid and compliant pads attached to a spring-loaded clamp. The pads are shaped to conform to the specimen surface to which the gauge is to be bonded. The shape of the pads permits the tool to align itself to the specimen and to maintain alignment of the gauge to the specimen during the bond curing process. A simplified method of attaching a strain gauge is provided by use of the tool.

  18. Strain and magnetic remanence

    NASA Astrophysics Data System (ADS)

    Borradaile, Graham John

    1993-05-01

    Experimental data may be compatible with the hypothesis that a single direction of magnetic remanence rotates as a rigid marker with strains up to 40% shortening in coaxial, perfect flattening ( X = Y > Z). Detailed agreement with the passive line model is relatively poor for the specimens in which remanance is carried by magnetite. However, for this range of strains the differences with the passive line model (Wettstein's equation) are so slight that the latter model may be more easily employed to de-strain or restore deformed remanance to its original attitude. In the case of hematite-bearing remanences, the differences between the passive line and rigid marker model are even smaller because of the higher aspect ratios of grains of hematite. Therefore it is suggested that Wettstein's equation may be safely used to restore remanence after even higher strains, where the remanence is carried by hematite.

  19. Nanowires enabling strained photovoltaics

    SciTech Connect

    Greil, J.; Bertagnolli, E.; Lugstein, A.; Birner, S.

    2014-04-21

    Photovoltaic nano-devices have largely been relying on charge separation in conventional p-n junctions. Junction formation via doping, however, imposes major challenges in process control. Here, we report on a concept for photovoltaic energy conversion at the nano scale without the need for intentional doping. Our approach relies on charge carrier separation in inhomogeneously strained germanium nanowires (Ge NWs). This concept utilizes the strain-induced gradient in bandgap along tapered NWs. Experimental data confirms the feasibility of strain-induced charge separation in individual vapor-liquid-solid grown Ge NW devices with an internal quantum efficiency of ∼5%. The charge separation mechanism, though, is not inherently limited to a distinct material. Our work establishes a class of photovoltaic nano-devices with its opto-electronic properties engineered by size, shape, and applied strain.

  20. Strains and Sprains

    MedlinePlus

    ... in the joint or muscle swelling and bruising warmth and redness of the injured area difficulty moving ... looks "bent" or misshapen signs of infection (increased warmth, redness, streaks, swelling, and pain) a strain or ...

  1. Sprains and Strains

    MedlinePlus

    ... people at risk for strains. Gymnastics, tennis, rowing, golf, and other sports that require extensive gripping can ... participating in any sport or exercise. Wear protective equipment when playing. Run on even surfaces. Information on ...

  2. Photothermal strain imaging

    NASA Astrophysics Data System (ADS)

    Choi, Changhoon; Ahn, Joongho; Jeon, Seungwan; Kim, Chulhong

    2017-07-01

    Vulnerable plaques are the major cause of cardiovascular disease, but they are difficult to detect with conventional intravascular imaging techniques. Techniques are needed to identify plaque vulnerability based on the presence of lipids in plaque. Thermal strain imaging (TSI) is an imaging technique based on ultrasound (US) wave propagation speed, which varies with the medium temperature. In TSI, the strain that occurs during tissue temperature change can be used for lipid detection because it has a different tendency depending on the type of tissue. Here, we demonstrate photothermal strain imaging (pTSI) using an intravascular ultrasound catheter. pTSI is performed by slightly and selectively heating lipid using a relatively inexpensive continuous laser source. We applied a speckle-tracking algorithm to US B-mode images for strain calculations. As a result, the strain produced in porcine fat was different from the strain produced in water-bearing gelatin phantom, which made it possible to distinguish the two. This suggests that pTSI could potentially be a way of differentiating lipids in coronary artery.

  3. Strain: Fact or Fiction?

    NASA Astrophysics Data System (ADS)

    Heilbronner, Renée

    2017-04-01

    2017 marks the 50th anniversary of the publication of John Ramsay's well known textbook "Folding and Fracturing of Rocks" - ... and the 30th anniversary of the rejection of a rather less well known paper entitled "Strain: Fact or Fiction?" submitted by Renée Panozzo to the Journal of Structural Geology. The gist of the paper was simple and straight forward: it was argued that not every fabric that can be observed in deformed rocks is necessarily a measure of the amount of strain the rock incurred. A distinction was made between a general "fabric", i.e., the traceable geometry of grain boundaries, for example, and a so-called "strain fabric", i.e., the model geometry that would result from homogeneously straining an initially isotropic fabric and that would exhibit at least orthorhombic symmetry. To verify if a given fabric was indeed a strain fabric it was therefore suggested to use the SURFOR method (published by Panozzo) and to carry out a so-called strain test, i.e., a check of symmetry, before interpreting the results of a fabric analysis in terms of strain. The problem with the paper was that it was very obviously written out of frustration. The frustration came form having reviewed a number of manuscripts which tried to use the then novel SURFOR method for strain analysis without first checking if the the fabric was a indeed a "strain fabric" or not, and then blaming the SURFOR method for producing ambiguous results. As a result, the paper was not exactly well balanced and carefully thought out. It was considered "interesting but not scholarly" by one of the reviewers and down-right offensive by the second. To tell the truth, however, the paper was not formally rejected. The editor Sue Treagus strongly encouraged Panozzo to revise the paper, ... and 30 years later, I will follow her advise and offer a revised paper as a tribute to John Ramsay. To quote from the original manuscript: "We should be a little more impressed that strain works so well, and less

  4. Isolation of a pigment-producing strain of Aeromonas liquefaciens from silver salmon (Oncorhynchus kisutch)

    USGS Publications Warehouse

    Ross, A.J.

    1962-01-01

    Aeromonas salmonicida, the etiological agent of furunculosis in fish, is distinctive in the field of fish diseases in that it may readily be recognized by the water-soluble reddish-brown pigment formed on culture media containing tyrosine. Additional tests for the identification of this organism include blackening of the colonial growth when flooded with an aqueous solution of p-phenylenediamine and a lack of motility (Griffin, Progressive Fish Culturist 14:74, 1952).

  5. Strain isolated ceramic coatings

    NASA Technical Reports Server (NTRS)

    Tolokan, R. P.; Brady, J. B.; Jarrabet, G. P.

    1985-01-01

    Plasma sprayed ceramic coatings are used in gas turbine engines to improve component temperature capability and cooling air efficiency. A compliant metal fiber strain isolator between a plasma sprayed ceramic coating and a metal substrate improves ceramic durability while allowing thicker coatings for better insulation. Development of strain isolated coatings has concentrated on design and fabrication of coatings and coating evaluation via thermal shock testing. In thermal shock testing, five types of failure are possible: buckling failure im compression on heat up, bimetal type failure, isothermal expansion mismatch failure, mudflat cracking during cool down, and long term fatigue. A primary failure mode for thermally cycled coatings is designated bimetal type failure. Bimetal failure is tensile failure in the ceramic near the ceramic-metal interface. One of the significant benefits of the strain isolator is an insulating layer protecting the metal substrate from heat deformation and thereby preventing bimetal type failure.

  6. Strain avalanches in plasticity

    NASA Astrophysics Data System (ADS)

    Argon, A. S.

    2013-09-01

    Plastic deformation at the mechanism level in all solids occurs in the form of discrete thermally activated individual stress relaxation events. While there are clear differences in mechanisms between dislocation mediated events in crystalline solids and by individual shear transformations in amorphous metals and semiconductors, such relaxation events interact strongly to form avalanches of strain bursts. In all cases the attendant distributions of released energy as amplitudes of acoustic emissions, or in serration amplitudes in flow stress, the levels of strain bursts are of fractal character with fractal exponents in the range from -1.5 to -2.0, having the character of phenomena of self-organized criticality, SOC. Here we examine strain avalanches in single crystals of ice, hcp metals, the jerky plastic deformations of nano-pillars of fcc and bcc metals deforming in compression, those in the plastic flow of bulk metallic glasses, all demonstrating the remarkable universality of character of plastic relaxation events.

  7. Strain gauge installation tool

    DOEpatents

    Conard, L.M.

    1998-06-16

    A tool and a method are disclosed for attaching a strain gauge to a test specimen by maintaining alignment of, and applying pressure to, the strain gauge during the bonding of the gauge to the specimen. The tool comprises rigid and compliant pads attached to a spring-loaded clamp. The pads are shaped to conform to the specimen surface to which the gauge is to be bonded. The shape of the pads permits the tool to align itself to the specimen and to maintain alignment of the gauge to the specimen during the bond curing process. A simplified method of attaching a strain gauge is provided by use of the tool. 6 figs.

  8. Muscle strain injuries.

    PubMed

    Garrett, W E

    1996-01-01

    One of the most common injuries seen in the office of the practicing physician is the muscle strain. Until recently, little data were available on the basic science and clinical application of this basic science for the treatment and prevention of muscle strains. Studies in the last 10 years represent action taken on the direction of investigation into muscle strain injuries from the laboratory and clinical fronts. Findings from the laboratory indicate that certain muscles are susceptible to strain injury (muscles that cross multiple joints or have complex architecture). These muscles have a strain threshold for both passive and active injury. Strain injury is not the result of muscle contraction alone, rather, strains are the result of excessive stretch or stretch while the muscle is being activated. When the muscle tears, the damage is localized very near the muscle-tendon junction. After injury, the muscle is weaker and at risk for further injury. The force output of the muscle returns over the following days as the muscle undertakes a predictable progression toward tissue healing. Current imaging studies have been used clinically to document the site of injury to the muscle-tendon junction. The commonly injured muscles have been described and include the hamstring, the rectus femoris, gastrocnemius, and adductor longus muscles. Injuries inconsistent with involvement of a single muscle-tendon junction proved to be at tendinous origins rather than within the muscle belly. Important information has also been provided regarding injuries with poor prognosis, which are potentially repairable surgically, including injuries to the rectus femoris muscle, the hamstring origin, and the abdominal wall. Data important to the management of common muscle injuries have been published. The risks of reinjury have been documented. The early efficacy and potential for long-term risks of nonsteroidal antiinflammatory agents have been shown. New data can also be applied to the field

  9. Radio frequency strain monitor

    NASA Technical Reports Server (NTRS)

    Heyman, Joseph S. (Inventor); Rogowski, Robert S. (Inventor); Holben, Jr., Milford S. (Inventor)

    1989-01-01

    A radio frequency strain monitor includes a voltage controlled oscillator for generating an oscillating signal that is input into a propagation path. The propagation path is preferably bonded to the surface of a structure to be monitored and produces a propagated signal. A phase difference between the oscillating and propagated signals is detected and maintained at a substantially constant value which is preferably a multiple of 90.degree. by changing the frequency of the oscillating signal. Any change in frequency of the oscillating signal provides an indication of strain in the structure to which the propagation path is bonded.

  10. Novel B19' strain glass with large recoverable strain

    NASA Astrophysics Data System (ADS)

    Liang, Qianglong; Wang, Dong; Zhang, Jian; Ji, Yuanchao; Ding, Xiangdong; Wang, Yu; Ren, Xiaobing; Wang, Yunzhi

    2017-08-01

    We report a strain glass state (B19' strain glass) in a Ni-rich TiNi shape memory alloy produced by cold rolling. As compared to previously reported strain glasses, this strain glass state has outstanding properties including quasilinear superelasticity with a large recoverable strain (˜4%), and slim hysteresis and high strength (˜1.0 GPa) over a wide temperature range (˜200 K). The existence of the B19' strain glass state is confirmed by (i) frequency dispersion of storage modulus, (ii) continuous decrease of electrical resistivity, and (iii) continuous growth of B19' nanodomains upon cooling. This study proves that the effect of defect strength on the creation of a strain glass state is in parallel to the effect of cooling rate on the creation of a structural glass, e.g., any strain crystal (i.e., martensite) can be turned into a strain glass if strong enough defects could be engineered.

  11. ConStrains identifies microbial strains in metagenomic datasets.

    PubMed

    Luo, Chengwei; Knight, Rob; Siljander, Heli; Knip, Mikael; Xavier, Ramnik J; Gevers, Dirk

    2015-10-01

    An important fraction of microbial diversity is harbored in strain individuality, so identification of conspecific bacterial strains is imperative for improved understanding of microbial community functions. Limitations in bioinformatics and sequencing technologies have to date precluded strain identification owing to difficulties in phasing short reads to faithfully recover the original strain-level genotypes, which have highly similar sequences. We present ConStrains, an open-source algorithm that identifies conspecific strains from metagenomic sequence data and reconstructs the phylogeny of these strains in microbial communities. The algorithm uses single-nucleotide polymorphism (SNP) patterns in a set of universal genes to infer within-species structures that represent strains. Applying ConStrains to simulated and host-derived datasets provides insights into microbial community dynamics.

  12. Repetitive strain injury.

    PubMed

    Al-Otaibi, S T

    2001-05-01

    Repetitive strain injury is a group of musculoskeletal disorders affecting muscles, tendons, nerves and blood vessels. These disorders could be attributed to occupational causes; however non-occupational causes should be excluded. The management of these cases required a multidisciplinary team approach.

  13. Strain gage barometric transmitter

    NASA Technical Reports Server (NTRS)

    Viton, P.

    1977-01-01

    A strain gage barometric transmitter for measuring the atmospheric pressure in severe environmental conditions is described. This equipment specifications are presented and its performance assessed. It is shown that this barometric sensor can measure the atmospheric pressure with a precision of 0.5 mb during a 6 month period.

  14. Sadovskii vortex in strain

    NASA Astrophysics Data System (ADS)

    Freilich, Daniel; Llewellyn Smith, Stefan

    2015-11-01

    Sadovskii vortices are patches of fluid with uniform vorticity surrounded by a vortex sheet. They were first constructed as models for wakes behind bluff objects. We investigate the Sadovskii vortex in a straining field and examine limiting cases to validate our computational method. One limit is the patch vortex in strain (Moore & Saffman, Aircraft wake turbulence and its detection 1971), where there is no vortex sheet. We solve this as a free-boundary problem, and show that a simple method using the Biot-Savart law quickly gives solutions for stable shapes. When used for the more elongated (stronger straining field) situations, the method also leads to new vortex shapes. In the hollow vortex case, where there is no vortex patch and the circulation is entirely due to the vortex sheet (Llewellyn Smith and Crowdy, J. Fluid Mech. 691 2012), we use the Birkhoff-Rott equation to calculate the velocity of the fluid on the vortex boundary. The combination of these two methods can then be used to calculate the shape and velocity field of the Sadovksii vortex in strain.

  15. Balloon film strain measurement

    NASA Astrophysics Data System (ADS)

    Rand, James L.

    In order to understand the state of stress in scientific balloons, a need exists for the measurement of film deformation in flight. The results of a flight test program are reported where material strain was measured for the first time during the inflation, launch, ascent and float of a typical natural shape, zero pressure scientific balloon.

  16. Highly stretchable miniature strain sensor for large dynamic strain measurement

    SciTech Connect

    Song, Bo; Yao, Shurong; Nie, Xu; Yu, Xun; Blecke, Jill

    2016-01-01

    In this paper, a new type of highly stretchable strain sensor was developed to measure large strains. The sensor was based on the piezo-resistive response of carbon nanotube (CNT)/polydimethylsiloxane (PDMS) composite thin films. The piezo-resistive response of CNT composite gives accurate strain measurement with high frequency response, while the ultra-soft PDMS matrix provides high flexibility and ductility for large strain measurement. Experimental results show that the CNT/PDMS sensor measures large strains (up to 8 %) with an excellent linearity and a fast frequency response. The new miniature strain sensor also exhibits much higher sensitivities than the conventional foil strain gages, as its gauge factor is 500 times of that of the conventional foil strain gages.

  17. Highly stretchable miniature strain sensor for large dynamic strain measurement

    DOE PAGES

    Song, Bo; Yao, Shurong; Nie, Xu; ...

    2016-01-01

    In this paper, a new type of highly stretchable strain sensor was developed to measure large strains. The sensor was based on the piezo-resistive response of carbon nanotube (CNT)/polydimethylsiloxane (PDMS) composite thin films. The piezo-resistive response of CNT composite gives accurate strain measurement with high frequency response, while the ultra-soft PDMS matrix provides high flexibility and ductility for large strain measurement. Experimental results show that the CNT/PDMS sensor measures large strains (up to 8 %) with an excellent linearity and a fast frequency response. The new miniature strain sensor also exhibits much higher sensitivities than the conventional foil strain gages,more » as its gauge factor is 500 times of that of the conventional foil strain gages.« less

  18. Strain patterns and strain accumulation along plate margins

    NASA Technical Reports Server (NTRS)

    Savage, J. C.

    1978-01-01

    Observations of strain accumulation along plate margins in Japan, New Zealand, and the United States indicate that: (1) a typical maximum rate of secular strain accumulation is on the order of 0.3 ppm/a, (2) a substantial part of the strain accumulation process can be attributed to slip at depth on the major plate boundary faults, and (3) some plastic deformation in a zone 100 km or more in width is apparently involved in the strain accumulation process.

  19. High temperature strain gages

    NASA Technical Reports Server (NTRS)

    Gregory, Otto J. (Inventor); You, Tao (Inventor)

    2011-01-01

    A ceramic strain gage based on reactively sputtered indium-tin-oxide (ITO) thin films is used to monitor the structural integrity of components employed in aerospace propulsion systems operating at temperatures in excess of 1500.degree. C. A scanning electron microscopy (SEM) of the thick ITO sensors reveals a partially sintered microstructure comprising a contiguous network of submicron ITO particles with well defined necks and isolated nanoporosity. Densification of the ITO particles was retarded during high temperature exposure with nitrogen thus stabilizing the nanoporosity. ITO strain sensors were prepared by reactive sputtering in various nitrogen/oxygen/argon partial pressures to incorporate more nitrogen into the films. Under these conditions, sintering and densification of the ITO particles containing these nitrogen rich grain boundaries was retarded and a contiguous network of nano-sized ITO particles was established.

  20. Novel strained superjunction VDMOS

    NASA Astrophysics Data System (ADS)

    Naugarhiya, Alok; Dubey, Shashank; Kondekar, Pravin N.

    2015-09-01

    In this paper, we have proposed novel strained superjunction (s-SJ) vertical double diffused MOS (VDMOS). Through channel engineering, we have introduced strain effects in s-SJ device using thin separate p-type silicon-germanium (p-SiGe) layer over silicon p-pillar. Further, we have designed process flow for the possible fabrication of s-SJ VDMOS. The proposed s-SJ devices fitted with less input capacitance (Cin) and 1.2∼3 times higher output current density than conventional SJ VDMOS. Therefore, 40% less gate charge (Qg) is required to turn-on the s-SJ VDMOS and Ron A is optimized in between 12% and 46%.

  1. Strain Gage Signal Interpretation.

    DTIC Science & Technology

    1986-02-01

    blades and vanes in many engines have been collected, played back and examined. The engine types encompass GE’s stable of turbine engines from the small...aeromechanical engineer . 1.3 SUMMARY OF RESULTS Strain gage signals from vibrating rotor blades and vanes were collected, examined, classified, and generalized...turboprops, to turbojets and to the large high bypass turbofan engines . Test conditions include all the phases that are investigated

  2. Strained Ring Energetic Binders

    DTIC Science & Technology

    1993-08-27

    polyhomobenzvalene ( PHBV ). PHBV was not found to have the mechanical instability problems of PBV, but was still thermally unstable (Tonset - 660C, Tmax - 1090C...DISCUSSION 4 Polybenzvalene (PBV) 4 Polyhomobenzvalene ( PHBV ) 6 Chain-Transfer Studies 11 CONCLUSIONS 15 EXPERIMENTAL PROCEDURES 16 .F 4E 19 APPENDICES A...strained ring polymers similar to PBV are known. The investigation of one of these polymers, polyhomobenzvalene ( PHBV ), is also described in this report

  3. Strain Measurement - Unidirectional.

    DTIC Science & Technology

    1983-04-20

    a ballpoint pen or a rounded piece of brass rod. If critical alignment is not necessary, gage lines may be located outside the immediate gage location...supplemented as needed by tabulated values. If the test design includes specification limits for the values, they should be included on the plots. Plots of...enough baseline before the event to allow estimation of the noise and stability. If the strain is to be correlated to specific events, the events should

  4. Symmetry in strain engineering of nanomembranes: making new strained materials.

    PubMed

    Paskiewicz, Deborah M; Scott, Shelley A; Savage, Donald E; Celler, George K; Lagally, Max G

    2011-07-26

    Strain in a material changes the lattice constant and thereby creates a material with new properties relative to the unstrained, but chemically identical, material. The ability to alter the strain (its magnitude, direction, extent, periodicity, symmetry, and nature) allows tunability of these new properties. A recent development, crystalline nanomembranes, offers a powerful platform for using and tuning strain to create materials that have unique properties, not achievable in bulk materials or with conventional processes. Nanomembranes, because of their thinness, enable elastic strain sharing, a process that introduces large amounts of strain and unique strain distributions in single-crystal materials, without exposing the material to the formation of extended defects. We provide here prescriptions for making new strained materials using crystal symmetry as the driver: we calculate the strain distributions in flat nanomembranes for two-fold and four-fold elastically symmetric materials. We show that we can controllably tune the amount of strain and the asymmetry of the strain distribution in elastically isotropic and anisotropic materials uniformly over large areas. We perform the experimental demonstration with a trilayer Si(110)/Si((1-x))Ge(x)(110)/Si(110) nanomembrane: an elastically two-fold symmetric system in which we can transfer strain that is biaxially isotropic. We are thus able to make uniformly strained materials that cannot be made any other way.

  5. Strain measurement based battery testing

    DOEpatents

    Xu, Jeff Qiang; Steiber, Joe; Wall, Craig M.; Smith, Robert; Ng, Cheuk

    2017-05-23

    A method and system for strain-based estimation of the state of health of a battery, from an initial state to an aged state, is provided. A strain gauge is applied to the battery. A first strain measurement is performed on the battery, using the strain gauge, at a selected charge capacity of the battery and at the initial state of the battery. A second strain measurement is performed on the battery, using the strain gauge, at the selected charge capacity of the battery and at the aged state of the battery. The capacity degradation of the battery is estimated as the difference between the first and second strain measurements divided by the first strain measurement.

  6. Strain balanced quantum posts

    SciTech Connect

    Alonso-Alvarez, D.; Alen, B.; Ripalda, J. M.; Llorens, J. M.; Taboada, A. G.; Briones, F.; Roldan, M. A.; Hernandez-Saz, J.; Hernandez-Maldonado, D.; Herrera, M.; Molina, S. I.

    2011-04-25

    Quantum posts are assembled by epitaxial growth of closely spaced quantum dot layers, modulating the composition of a semiconductor alloy, typically InGaAs. In contrast with most self-assembled nanostructures, the height of quantum posts can be controlled with nanometer precision, up to a maximum value limited by the accumulated stress due to the lattice mismatch. Here, we present a strain compensation technique based on the controlled incorporation of phosphorous, which substantially increases the maximum attainable quantum post height. The luminescence from the resulting nanostructures presents giant linear polarization anisotropy.

  7. Repetitive strain injury.

    PubMed

    van Tulder, Maurits; Malmivaara, Antti; Koes, Bart

    2007-05-26

    Repetitive strain injury remains a controversial topic. The term repetitive strain injury includes specific disorders such as carpal tunnel syndrome, cubital tunnel syndrome, Guyon canal syndrome, lateral epicondylitis, and tendonitis of the wrist or hand. The diagnosis is usually made on the basis of history and clinical examination. Large high-quality studies using newer imaging techniques, such as MRI and ultrasonography are few. Consequently, the role of such imaging in diagnosis of upper limb disorders remains unclear. In many cases, no specific diagnosis can be established and complaints are labelled as non-specific. Little is known about the effectiveness of treatment options for upper limb disorders. Strong evidence for any intervention is scarce and the effect, if any, is mainly short-term pain relief. Exercise is beneficial for non-specific upper limb disorders. Immobilising hand braces and open carpal tunnel surgery release are beneficial for carpal tunnel syndrome, and topical and oral non-steroidal anti-inflammatory drugs, and corticosteroid injections are helpful for lateral epicondylitis. Exercise is probably beneficial for neck pain, as are corticosteroid injections and exercise for shoulder pain. Although upper limb disorders occur frequently in the working population, most trials have not exclusively included a working population or assessed effects on work-related outcomes. Further high-quality trials should aim to include sufficient sample sizes, working populations, and work-related outcomes.

  8. Sadovskii vortex in strain

    NASA Astrophysics Data System (ADS)

    Freilich, Daniel; Llewellyn Smith, Stefan

    2014-11-01

    A Sadovskii vortex is a patch of fluid with uniform vorticity surrounded by a vortex sheet. Using a boundary element type method, we investigate the steady states of this flow in an incompressible, inviscid straining flow. Outside the vortex, the fluid is irrotational. In the limiting case where the entire circulation is due to the vortex patch, this is a patch vortex (Moore & Saffman, Aircraft wake turbulence and its detection 1971). In the other limiting case, where all the circulation is due to the vortex sheet, this is a hollow vortex (Llewellyn Smith and Crowdy, J. Fluid Mech. 691, 2012). This flow has two governing nondimensional parameters, relating the strengths of the straining field, vortex sheet, and patch vorticity. We study the relationship between these two parameters, and examine the shape of the resulting vortices. We also work towards a bifurcation diagram of the steady states of the Sadovskii vortex in an attempt to understand the connection between vortex sheet and vortex patch desingularizations of the point vortex. Support from NSF-CMMI-0970113.

  9. Colony Dimorphism in Bradyrhizobium Strains

    PubMed Central

    Sylvester-Bradley, Rosemary; Thornton, Philip; Jones, Peter

    1988-01-01

    Ten isolates of Bradyrhizobium spp. which form two colony types were studied; the isolates originated from a range of legume species. The two colony types differed in the amount of gum formed or size or both, depending on the strain. Whole 7-day-old colonies of each type were subcultured to determine the proportion of cells which had changed to the other type. An iterative computerized procedure was used to determine the rate of switching per generation between the two types and to predict proportions reached at equilibrium for each strain. The predicted proportions of the wetter (more gummy) or larger colony type at equilibrium differed significantly between strains, ranging from 0.9999 (strain CIAT 2383) to 0.0216 (strain CIAT 2469), because some strains switched faster from dry to wet (or small to large) and others switched faster from wet to dry (or large to small). Predicted equilibrium was reached after about 140 generations in strain USDA 76. In all but one strain (CIAT 3030) the growth rate of the wetter colony type was greater than or similar to that of the drier type. The mean difference in generation time between the two colony types was 0.37 h. Doubling times calculated for either colony type after 7 days of growth on the agar surface ranged from 6.0 to 7.3 h. The formation of two persistent colony types by one strain (clonal or colony dimorphism) may be a common phenomenon among Bradyrhizobium strains. Images PMID:16347599

  10. Geodetic strain measurements in Washington.

    USGS Publications Warehouse

    Savage, J.C.; Lisowski, M.; Prescott, W.H.

    1981-01-01

    Two new geodetic measurements of strain accumulation in the state of Washington for the interval 1972-1979 are reported. Near Seattle the average principal strain rates are 0.07 + or - 0.03 mu strain/yr N19oW and -0.13 + or - 0.02 mu strain/yr N71oE, and near Richland (south central Washington) the average principal strain rates are -0.02 + or - 0.01 mu strain/yr N36oW and -0.04 + or - 0.01 mu strain/yr N54oE. Extension is taken as positive, and the uncertainties quoted are standard deviations. A measurement of shear strain accumulation (dilation not determined) in the epoch 1914- 1966 along the north coast of Vancouver Island by the Geodetic Survey of Canada indicates a marginally significant accumulation of right-lateral shear (0.06 + or - 0.03 mu rad/yr) across the plate boundary (N40oW strike). Although there are significant differences in detail, these strain measurements are roughly consistent with a crude dislocation model that represents subduction of the Juan de Fuca plate. The observed accumulation of strain implies that large, shallow, thrust earthquakes should be expected off the coast of Washington and British Columbia. However, this conclusion is not easily reconciled with either observations of elevation change along the Washington coast or the focal mechanism solutions for shallow earthquakes in Washington. -Authors

  11. Strain Pattern in Supercooled Liquids

    NASA Astrophysics Data System (ADS)

    Illing, Bernd; Fritschi, Sebastian; Hajnal, David; Klix, Christian; Keim, Peter; Fuchs, Matthias

    2016-11-01

    Investigations of strain correlations at the glass transition reveal unexpected phenomena. The shear strain fluctuations show an Eshelby-strain pattern [˜cos (4 θ ) /r2 ], characteristic of elastic response, even in liquids, at long times. We address this using a mode-coupling theory for the strain fluctuations in supercooled liquids and data from both video microscopy of a two-dimensional colloidal glass former and simulations of Brownian hard disks. We show that the long-ranged and long-lived strain signatures follow a scaling law valid close to the glass transition. For large enough viscosities, the Eshelby-strain pattern is visible even on time scales longer than the structural relaxation time τ and after the shear modulus has relaxed to zero.

  12. Casimir interaction of strained graphene

    NASA Astrophysics Data System (ADS)

    Bordag, M.; Fialkovsky, I.; Vassilevich, D.

    2017-08-01

    We calculate the Casimir interaction of two freestanding graphene samples under uniaxial strain. Our approach fully takes retardation and dispersion into account and is based on quantum field theoretical expressions for conductivities in terms of the polarization operator. Contrary to some recent results the force shows a rather weak dependence on the realistic values of strain, changing just by a few percent in its maximum as compared to the non-strained case.

  13. Strain gage adhesives -- Operating characteristics

    NASA Astrophysics Data System (ADS)

    Hannah, R. L.; Reese, R. T.

    1994-02-01

    This paper is concerned with the adhesives which are used to bond the strain gages to substrates. Strain gage installations include four basic parts: the gage, the adhesive used to attach the gage to the stressed surface, the coatings used to protect the gage over its service life, and the electrical circuitry and data acquisition system used to record the strains. This paper describes the operating characteristics of the adhesives. The figures developed in this paper summarize the information available on adhesives from excellent manufacturer's catalogs, texts and references, and from experiences from the SEM Western Regional Strain Gage Committee.

  14. Thermal strain imaging: a review

    PubMed Central

    Seo, Chi Hyung; Shi, Yan; Huang, Sheng-Wen; Kim, Kang; O'Donnell, Matthew

    2011-01-01

    Thermal strain imaging (TSI) or temporal strain imaging is an ultrasound application that exploits the temperature dependence of sound speed to create thermal (temporal) strain images. This article provides an overview of the field of TSI for biomedical applications that have appeared in the literature over the past several years. Basic theory in thermal strain is introduced. Two major energy sources appropriate for clinical applications are discussed. Promising biomedical applications are presented throughout the paper, including non-invasive thermometry and tissue characterization. We present some of the limitations and complications of the method. The paper concludes with a discussion of competing technologies. PMID:22866235

  15. High temperature strain gage evaluation

    NASA Technical Reports Server (NTRS)

    Gonzalez, J. I.

    1977-01-01

    The structural thermal test of an advanced ramjet missile section required strain measurements as high as 922 K (1200 F). Since there is relatively little experience in the use of strain gages above the 700-755 K (800-900 F) level, a program was initiated to select and evaluate the best available gage. Candidate gages suitable for measurements up to 922 K (1200 F) were selected. This involved the determination of their operating characteristics, availability, cost, installation aspects, etc. The evaluation involved the following tests: strain as a function of load at room temperature and apparent strain as a function of temperature.

  16. Hydrogen production from microbial strains

    DOEpatents

    Harwood, Caroline S; Rey, Federico E

    2012-09-18

    The present invention is directed to a method of screening microbe strains capable of generating hydrogen. This method involves inoculating one or more microbes in a sample containing cell culture medium to form an inoculated culture medium. The inoculated culture medium is then incubated under hydrogen producing conditions. Once incubating causes the inoculated culture medium to produce hydrogen, microbes in the culture medium are identified as candidate microbe strains capable of generating hydrogen. Methods of producing hydrogen using one or more of the microbial strains identified as well as the hydrogen producing strains themselves are also disclosed.

  17. Adaptor for Measuring Principal Strains with Tuckerman Strain Gage

    NASA Technical Reports Server (NTRS)

    Mcpherson, A E

    1943-01-01

    An adapter is described which uses three Tuckerman optical strain gages to measure the displacement of the three vortices of an equilateral triangle along lines 120 degrees apart. These displacements are substituted in well-known equations in order to compute the magnitude and direction of the principal strains. Tests of the adaptor indicate that principal strains over a gage length of 1.42 inch may be measured with a systematic error not exceeding 4 percent and a mean observational error of the order of + or minus 0.000006. The maximum observed error in strain was of the order of 0.00006. The directions of principal strains for unidirectional stress were measured with the adaptor with an average error of the order of 1 degree.

  18. Strain relaxation in nanopatterned strained silicon round pillars

    NASA Astrophysics Data System (ADS)

    Himcinschi, C.; Singh, R.; Radu, I.; Milenin, A. P.; Erfurth, W.; Reiche, M.; Gösele, U.; Christiansen, S. H.; Muster, F.; Petzold, M.

    2007-01-01

    Periodic arrays of strained Si (sSi) round nanopillars were fabricated on sSi layers deposited on SiGe virtual substrates by electron-beam lithography and subsequent reactive-ion etching. The strain in the patterned sSi nanopillars was determined using high-resolution UV micro-Raman spectroscopy. The strain relaxes significantly upon nanostructuring: from 0.9% in the unpatterned sSi layer to values between 0.22% and 0.57% in the round sSi pillars with diameters from 100 up to 500nm. The strain distribution in the sSi nanopillars was analyzed by finite element (FE) modeling. The FE calculations confirm the strain relaxation after patterning, in agreement with the results obtained from Raman spectroscopy.

  19. Strained graphene Hall bar

    NASA Astrophysics Data System (ADS)

    Milovanović, S. P.; Peeters, F. M.

    2017-02-01

    The effects of strain, induced by a Gaussian bump, on the magnetic field dependent transport properties of a graphene Hall bar are investigated. The numerical simulations are performed using both classical and quantum mechanical transport theory and we found that both approaches exhibit similar characteristic features. The effects of the Gaussian bump are manifested by a decrease of the bend resistance, R B, around zero-magnetic field and the occurrence of side-peaks in R B. These features are explained as a consequence of bump-assisted scattering of electrons towards different terminals of the Hall bar. Using these features we are able to give an estimate of the size of the bump. Additional oscillations in R B are found in the quantum description that are due to the population/depopulation of Landau levels. The bump has a minor influence on the Hall resistance even for very high values of the pseudo-magnetic field. When the bump is placed outside the center of the Hall bar valley polarized electrons can be collected in the leads.

  20. Biomechanical strain of goldsmiths.

    PubMed

    Cândido, Paula Emanuela Fernandes; Teixeira, Juliana Vieira Schmidt; Moro, Antônio Renato Pereira; Gontijo, Leila Amaral

    2012-01-01

    The work of the goldsmiths consists in the manufacture of jewelry. The piece, be it an earring, bracelet or necklace, is hand-assembled. This task requires precision, skill, kindness and patience. In this work, we make use of tools such as cuticle clippers and rounded tip, beads or precious stones and also pieces of metal. This type of activity requires a biomechanical stress of hands and wrists. In order to quantify the biomechanical stress, we performed a case study to measure the movements performed by an assembly of pieces of jewelry. As method for research, filming was done during assembly of parts to a paste, using a Nikon digital camera, for 1 (one) hour. The film was edited by Kinovea software, and the task was divided into cycles, each cycle corresponds to a complete object. In one cycle, there are four two movements of supination and pronation movements of the forearm. The cycle lasts approximately sixteen seconds, totaling 1800 cycles in eight hours. Despite the effort required of the wrists, the activity shows no complaints from the employees, but this fact does not mischaracterizes the ability of employees to acquire repetitive strain injuries and work-related musculoskeletal disorders.

  1. Hypothetical strain-free oligoradicals

    PubMed Central

    Hoffmann, Roald; Eisenstein, Odile; Balaban, Alexandru T.

    1980-01-01

    Several new classes of oligoradicals free of angle strain are suggested and examined by means of molecular orbital calculations. The collapse products of these hypothetical radicals are highly strained molecules. Various electronic strategies for the stabilization of these oligoradicals have been explored. PMID:16592882

  2. Difference Between Strain and Sprain.

    ERIC Educational Resources Information Center

    Connors, G. Patrick

    Provided in this description of the differences between a strain (damage to the muscle or tendon) and a sprain (damage to the ligament) are definitions of mild, moderate, and severe (first, second, and third degree) strains and sprains. A final caution is given that these are two separate and distinct problems and should be treated as such. (DC)

  3. Difference Between Strain and Sprain.

    ERIC Educational Resources Information Center

    Connors, G. Patrick

    Provided in this description of the differences between a strain (damage to the muscle or tendon) and a sprain (damage to the ligament) are definitions of mild, moderate, and severe (first, second, and third degree) strains and sprains. A final caution is given that these are two separate and distinct problems and should be treated as such. (DC)

  4. Moire strain analysis of paper

    Treesearch

    R. E. Rowlands; P. K. Beasley; D. E. Gunderson

    1983-01-01

    Efficient use of paper products involves using modern aspects of materials science and engineering mechanics. This implies the ability to determine simultaneously different components of strain at multiple locations and under static or dynamic conditions. Although measuring strains in paper has been a topic of interest for over 40 years, present capability remains...

  5. Characterization of Salmonella enteritidis strains.

    PubMed Central

    Poppe, C; McFadden, K A; Brouwer, A M; Demczuk, W

    1993-01-01

    A study was conducted to characterize 318 Salmonella enteritidis strains that were mainly isolated from poultry and their environment in Canada. Biotype, phagetype (PT), plasmid profile (PP), hybridization with a plasmid-derived virulence sequence probe, antibiotic resistance, outer membrane proteins (OMPs), and lipopolysaccharide (LPS) profiles were determined. Relationships of these properties to one another, and their diagnostic and pathogenic significance were assessed. Biotyping indicated that failure to ferment rhamnose was sometimes useful as a marker for epidemiologically related strains. Phagetyping was the most effective method for subdividing S. enteritidis; it distinguished 12 PTs. Phagetype 13 was occasionally associated with septicemia and mortality in chickens. The strains belonged to 15 PPs. A 36 megadalton (MDa) plasmid was found in 97% of the strains. Only the 36 MDa plasmid hybridized with the probe. Seventeen percent of the strains were drug resistant; all strains were sensitive to ciprofloxacin. Thirty-five of 36 strains possessed the same OMP profile, and 36 of 41 strains contained smooth LPS. Images Fig. 1. PMID:8358678

  6. Bacterial succession during curing process of a skate (Dipturus batis) and isolation of novel strains.

    PubMed

    Reynisson, E; Thornór Marteinsson, V; Jónsdóttir, R; Magnússon, S H; Hreggvidsson, G O

    2012-08-01

    To study the succession of cultivated and uncultivated microbes during the traditional curing process of skate. The microbial diversity was evaluated by sequencing 16Sr RNA clone libraries and cultivation in variety of media from skate samples taken periodically during a 9-day curing process. A pH shift was observed (pH 6·64-9·27) with increasing trimethylamine (2·6 up to 75·6 mg N per 100 g) and total volatile nitrogen (TVN) (from 58·5 to 705·8 mg N per 100 g) but with relatively slow bacterial growth. Uncured skate was dominated by Oceanisphaera and Pseudoalteromonas genera but was substituted after curing by Photobacterium and Aliivibrio in the flesh and Pseudomonas on the skin. Almost 50% of the clone library is derived from putative undiscovered species. Cultivation and enrichment strategies resulted in isolation of putatively new species belonging to the genera Idiomarina, Rheinheimera, Oceanisphaera, Providencia and Pseudomonas. The most abundant genera able to hydrolyse urea to ammonia were Oceanisphaera, Psychrobacter, Pseudoalteromonas and isolates within the Pseudomonas genus. The curing process of skate is controlled and achieved by a dynamic bacterial community where the key players belong to Oceanisphaera, Pseudoalteromonas, Photobacterium, Aliivibrio and Pseudomonas. For the first time, the bacterial population developments in the curing process of skate are presented and demonstrate a reservoir of many yet undiscovered bacterial species. No Claim to Norwegian Government works Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

  7. Strain gage system evaluation program

    NASA Technical Reports Server (NTRS)

    Dolleris, G. W.; Mazur, H. J.; Kokoszka, E., Jr.

    1978-01-01

    A program was conducted to determine the reliability of various strain gage systems when applied to rotating compressor blades in an aircraft gas turbine engine. A survey of current technology strain gage systems was conducted to provide a basis for selecting candidate systems for evaluation. Testing and evaluation was conducted in an F 100 engine. Sixty strain gage systems of seven different designs were installed on the first and third stages of an F 100 engine fan. Nineteen strain gage failures occurred during 62 hours of engine operation, for a survival rate of 68 percent. Of the failures, 16 occurred at blade-to-disk leadwire jumps (84 percent), two at a leadwire splice (11 percent), and one at a gage splice (5 percent). Effects of erosion, temperature, G-loading, and stress levels are discussed. Results of a post-test analysis of the individual components of each strain gage system are presented.

  8. Residual strains in conduit arteries.

    PubMed

    Rachev, A; Greenwald, S E

    2003-05-01

    Residual strains and stresses are those that exist in a body when all external loads are removed. Residual strains in arteries can be characterized by the opening angle of the sector-like cross-section which arises when an unloaded ring segment is radially cut. A review of experimental methods for measuring residual strains and the main results about the variation of the opening angle with arterial localization, age, smooth muscle activity, mechanical environment and certain vascular pathologies are presented and discussed. It is shown that, in addition to their well-established ability to homogenize the stress field in the arterial wall, residual strains make arteries more compliant and thereby improve their performance as elastic reservoirs and ensure more effective local control of the arterial lumen by smooth muscle cells. Finally, evidence that, in some cases, residual strains remain in arteries even after they have been cut radially is discussed.

  9. Strain Insensitive Optical Phase Locked Loop

    NASA Technical Reports Server (NTRS)

    Egalon, Claudio O. (Inventor); Rogowski, Robert S. (Inventor)

    1998-01-01

    A strain sensor uses optical fibers including strain insensitive portions and a strain sensitive portion. The optical fibers form a sensitive arm of an optical phase locked loop (OPLL). The use of the OPLL allows for multimode optical fiber to be used in a strain insensitive configuration. Only strain information for the strain sensitive portion is monitored rather than the integrated strain measurements commonly made with optical fiber sensors.

  10. High temperature strain measurement with a resistance strain gage

    NASA Technical Reports Server (NTRS)

    Lei, Jih-Fen; Fichtel, ED; Mcdaniel, Amos

    1993-01-01

    A PdCr based electrical resistance strain gage was demonstrated in the laboratory to be a viable sensor candidate for static strain measurement at high temperatures. However, difficulties were encountered while transferring the sensor to field applications. This paper is therefore prepared for recognition and resolution of the problems likely to be encountered with PdCr strain gages in field applications. Errors caused by the measurement system, installation technique and lead wire attachment are discussed. The limitations and some considerations related to the temperature compensation technique used for this gage are also addressed.

  11. Recent advances in echocardiography: strain and strain rate imaging

    PubMed Central

    Mirea, Oana; Duchenne, Jurgen; Voigt, Jens-Uwe

    2016-01-01

    Deformation imaging by echocardiography is a well-established research tool which has been gaining interest from clinical cardiologists since the introduction of speckle tracking. Post-processing of echo images to analyze deformation has become readily available at the fingertips of the user. New parameters such as global longitudinal strain have been shown to provide added diagnostic value, and ongoing efforts of the imaging societies and industry aimed at harmonizing methods will improve the technique further. This review focuses on recent advances in the field of echocardiographic strain and strain rate imaging, and provides an overview on its current and potential future clinical applications. PMID:27158476

  12. STRAIN LOCALIZATION IN IRRADIATED MATERIALS

    SciTech Connect

    Byun, Thak Sang; Hashimoto, Naoyuki

    2006-01-01

    Low temperature irradiation can significantly harden metallic materials and often lead to strain localization and ductility loss in deformation. This paper provides a review on the radiation effects on the deformation of metallic materials, focusing on microscopic and macroscopic strain localization phenomena. The microscopic strain localization often observed in irradiated materials are dislocation channeling and deformation twinning, in which dislocation glides are evenly distributed and well confined in the narrow bands, usually a fraction of a micron wide. Dislocation channeling is a common strain localization mechanism observed virtually in all irradiated metallic materials with ductility, while deformation twinning is an alternative localization mechanism occurring only in low stacking fault energy materials. In some high stacking fault energy materials where cross slip is easy, curved and widening channels can be formed depending on dose and stress state. Irradiation also prompts macroscopic strain localization (or plastic instability). It is shown that the plastic instability stress and true fracture stress are nearly independent of irradiation dose if there is no radiation-induced phase change or embrittlement. A newly proposed plastic instability criterion is that the metals after irradiation show necking at yield when the yield stress exceeds the dose-independent plastic instability stress. There is no evident relationship between the microscopic and macroscopic strain localizations; which is explained by the long-range back-stress hardening. It is proposed that the microscopic strain localization is a generalized phenomenon occurring at high stress.

  13. Radio Frequency (RF) strain monitor

    NASA Technical Reports Server (NTRS)

    Heyman, Joseph S. (Inventor); Rogowski, Robert S. (Inventor); Holben, Milford S., Jr. (Inventor)

    1988-01-01

    This invention relates to an apparatus for measuring strain in a structure. In particular, the invention detects strain in parts per million to over ten percent along an entire length (or other dimension) of a structure measuring a few millimeters to several kilometers. By using a propagation path bonded to the structure, the invention is not limited by the signal attenuation characteristics of the structure and thus frequencies in the megahertz to gigahertz range may be used to detect strain in part per million to over ten percent with high precision.

  14. Low TCR nanocomposite strain gages

    NASA Technical Reports Server (NTRS)

    Gregory, Otto J. (Inventor); Chen, Ximing (Inventor)

    2012-01-01

    A high temperature thin film strain gage sensor capable of functioning at temperatures above 1400.degree. C. The sensor contains a substrate, a nanocomposite film comprised of an indium tin oxide alloy, zinc oxide doped with alumina or other oxide semiconductor and a refractory metal selected from the group consisting of Pt, Pd, Rh, Ni, W, Ir, NiCrAlY and NiCoCrAlY deposited onto the substrate to form an active strain element. The strain element being responsive to an applied force.

  15. Virtual strain gage size study

    SciTech Connect

    Reu, Phillip L.

    2015-09-22

    DIC is a non-linear low-pass spatial filtering operation; whether we consider the effect of the subset and shape function, the strain window used in the strain calculation, of other post-processing of the results, each decision will impact the spatial resolution, of the measurement. More fundamentally, the speckle size limits, the spatial resolution by dictating the smallest possible subset. After this decision the processing settings are controlled by the allowable noise level balanced by possible bias errors created by the data filtering. This article describes a process to determine optimum DIC software settings to determine if the peak displacements or strains are being found.

  16. Strain accumulation in quasicrystalline solids

    NASA Technical Reports Server (NTRS)

    Nori, Franco; Ronchetti, Marco; Elser, Veit

    1988-01-01

    The relaxation of two-dimensional quasicrystalline elastic networks when their constituent bonds are perturbed homogeneously is studied. Whereas ideal, quasi-periodic networks are stable against such perturbations, significant accumulations of strain in a class of disordered networks generated by a growth process are found. The grown networks are characterized by root mean square phason fluctuations which grow linearly with system size. The strain accumulation observed in these networks also grows linearly with system size. Finally, dependence of strain accumulation on cooling rate is found.

  17. What Are Sprains and Strains?

    MedlinePlus

    ... a lot. Examples are gymnastics, tennis, rowing, and golf. People who play these sports sometimes strain their ... and stretch before playing a sport. Wear protective equipment when playing. Run on flat surfaces. For More ...

  18. Magnetic Domain Strain Sensor Program

    DTIC Science & Technology

    1990-08-01

    static strain measurement at elevated temperatures. 2.2 Magnetic Strain Measurement Theory The initial work at GED investigated the Barkhausen effect...including large and small Barkhausen jumps. This is a wave propaga- tion phenomenon in which a magnetic wave velocity is measured. The wave velocity in a...theory explaining the phenomenon that deviates from the Barkhausen effect. Some basic concepts had to be examined to better understand magnetic phenomena

  19. PLASTICITY AND NON-LINEAR ELASTIC STRAINS

    DTIC Science & Technology

    conditions existing in plane waves in an extended medium to give the time rate of change of stress as a function of the time rate of change of strain, the stress invariants, the total strain and the plastic strain. (Author)

  20. The Spot 42 RNA: A regulatory small RNA with roles in the central metabolism

    PubMed Central

    Bækkedal, Cecilie; Haugen, Peik

    2015-01-01

    The Spot 42 RNA is a 109 nucleotide long (in Escherichia coli) noncoding small regulatory RNA (sRNA) encoded by the spf (spot fourty-two) gene. spf is found in gamma-proteobacteria and the majority of experimental work on Spot 42 RNA has been performed using E. coli, and recently Aliivibrio salmonicida. In the cell Spot 42 RNA plays essential roles as a regulator in carbohydrate metabolism and uptake, and its expression is activated by glucose, and inhibited by the cAMP-CRP complex. Here we summarize the current knowledge on Spot 42, and present the natural distribution of spf, show family-specific secondary structural features of Spot 42, and link highly conserved structural regions to mRNA target binding. PMID:26327359

  1. Magnetic susceptibility, petrofabrics and strain

    NASA Astrophysics Data System (ADS)

    Borradaile, Graham John

    1988-12-01

    Magnetic susceptibility is a non-destructive technique for quantifying the average fabric of a small sample of rock. The interpretation of the magnetic fabric is not always straightforward. However, the principal directions of the magnitude ellipsoid of susceptibility commonly show orientations consistent with the kinematic interpretations of folds, shear zones and other structural features. The directions may correspond with the orientations of strained objects or with the planar-linear mineral orientations. There will usually be multiple mineralogical sources of susceptibility, often involving silicates. If the sources are known, or if the susceptibility can be attributed to a single mineral species, it may be possible to establish a correlation between the strain ellipsoid and the susceptibility ellipsoid. This correlation will be of principal directions in many instances and occasionally there may be a weak correlation of strain magnitudes as well. In other circumstances it may be possible to establish a correlation between changes in susceptibility and the strain. Nevertheless magnetic fabric studies are not routine substitutes for strain analysis. Even where information on strain is not provided, the magnetic fabrics (and subfabrics) yield a measure of the preferred crystallographic orientation or preferred dimensional orientation of the minerals that may be integrated profitably with other petrofabric data. Experimental deformation of certain synthetic aggregates indicates that directions of magnetic susceptibility spin rapidly with advancing strain, especially where the matrix grains undergo crystal-plastic deformation. In certain experiments, simple shear appears to change the intensity of magnetic fabric more effectively than pure shear. Experiments indicate also that the initial anisotropy of a rock-like material is not easily overprinted by deformation whereas field studies are equivocal.

  2. Applications of strained layer superlattices

    NASA Astrophysics Data System (ADS)

    Smith, D. L.; Laurich, B. K.; Mailhiot, C.

    1990-04-01

    Because of different band edge lineups, strain conditions, and growth orientations, various strained layer superlattice (SLS) materials can exhibit qualitatively new physical behavior in their optical properties. Two examples are given of new physical behavior in SLS: strain generated electric fields in polar growth axis superlattices and strained type 2 superlattices. In SLS, large electric fields can be generated by the piezoelectric effect. The fields are largest for SLS with a (111) growth axis; they vanish for SLS with a (100) growth axis. The strain generated electric fields strongly modify the optical properties of the superlattice. Photogenerated electron-hole pairs screen the fields leading to a large nonlinear optical response. Application of an external electric field leads to a large linear electrooptical response. The absorption edge can be either red or blue shifted. Optical studies of (100), (111), and (211) oriented GaInAs/GaAs superlattices confirm the existence of the strain generated electric fields. Small band gap semiconductors are useful for making intrinsic long wavelength infrared detectors. Arbitrarily small band gaps can be reached in the type 2 superlattice InAs/GaSb. However, for band gaps less than 0.1 eV, the layer thicknesses are large and the overlap of electron and hole wavefunctions are small. Thus, the absorption coefficient is too small for useful infrared (IR) detection. Including In in the GaSb introduces strain in he InAs/GaInSb superlattice which shifts the band edges so that small band gaps can be reached in thin layer superlattices. Good absorption at long IR wavelengths is thus achieved.

  3. Optical Strain Measurement System Development

    NASA Technical Reports Server (NTRS)

    Lant, C. T.

    1985-01-01

    Investigations of physical phenomena affecting the durability of SSME components require measurement systems operational in hostile environments. The need for such instrumentation caused the definition and operation of an optical strain measurement system. This optical strain measurement system based on the speckle shift method is being developed. This is a noncontact, automatic method of measuring surface strain in one dimension that corrects for error due to rigid body motion. It provides a gauge length of 1 to 2 mm and allows the region of interest on the test specimen to be mapped point by point. The output is a graphics map of the points inspected on the specimen; data points is stored in quasi-real time. This is the first phase of a multiphase effort in optical strain measurement. The speckle pattern created by the test specimen is interpreted as high order interference fringes resulting from a random diffraction grating, being the natural surface roughness of the specimen. Strain induced on the specimen causes a change in spacing of the surface roughness, which in turn shifts the position of the interference pattern (speckles).

  4. Optical Strain Measurement System Development

    NASA Technical Reports Server (NTRS)

    Lant, C. T.

    1985-01-01

    Investigations of physical phenomena affecting the durability of SSME components require measurement systems operational in hostile environments. The need for such instrumentation caused the definition and operation of an optical strain measurement system. This optical strain measurement system based on the speckle shift method is being developed. This is a noncontact, automatic method of measuring surface strain in one dimension that corrects for error due to rigid body motion. It provides a gauge length of 1 to 2 mm and allows the region of interest on the test specimen to be mapped point by point. The output is a graphics map of the points inspected on the specimen; data points is stored in quasi-real time. This is the first phase of a multiphase effort in optical strain measurement. The speckle pattern created by the test specimen is interpreted as high order interference fringes resulting from a random diffraction grating, being the natural surface roughness of the specimen. Strain induced on the specimen causes a change in spacing of the surface roughness, which in turn shifts the position of the interference pattern (speckles).

  5. A thin film strain transducer

    NASA Technical Reports Server (NTRS)

    Rand, J. L.

    1983-01-01

    A device has been developed for the purpose of measuring longitudinal strain in thin polyethylene films. This paper describes the design, development, calibration, and application of this unique transducer in a variety of low temperature environments. This thin, ring-shaped device has a low effective modulus so as not to interfere with the strain that would naturally occur in a thin film. It has a standard 350 ohm impedance which is compatible with most available bridge balance, amplification, and telemetry instrumentation. This transducer has been successfully used for viscoelastic material characterization experiments in the laboratory, as well as in flight measurements of strain on the surface of scientific balloons during inflation, launch, ascent, and float.

  6. Measuring mine roof bolt strains

    DOEpatents

    Steblay, Bernard J.

    1986-01-01

    A mine roof bolt and a method of measuring the strain in mine roof bolts of this type are disclosed. According to the method, a flat portion on the head of the mine roof bolt is first machined. Next, a hole is drilled radially through the bolt at a predetermined distance from the bolt head. After installation of the mine roof bolt and loading, the strain of the mine roof bolt is measured by generating an ultrasonic pulse at the flat portion. The time of travel of the ultrasonic pulse reflected from the hole is measured. This time of travel is a function of the distance from the flat portion to the hole and increases as the bolt is loaded. Consequently, the time measurement is correlated to the strain in the bolt. Compensation for various factors affecting the travel time are also provided.

  7. Taxonomy of oxalotrophic Methylobacterium strains

    NASA Astrophysics Data System (ADS)

    Sahin, Nurettin; Kato, Yuko; Yilmaz, Ferah

    2008-10-01

    Most of the oxalotrophic bacteria are facultative methylotrophs and play important ecological roles in soil fertility and cycling of elements. This study gives a detailed picture of the taxonomy and diversity of these bacteria and provides new information about the taxonomical variability within the genus Methylobacterium. Twelve mesophilic, pink-pigmented, and facultatively methylotrophic oxalate-oxidizing strains were included in this work that had been previously isolated from the soil and some plant tissues by the potassium oxalate enrichment method. The isolates were characterized using biochemical tests, cellular lipid profiles, spectral characteristics of carotenoid pigments, G+C content of the DNA, and 16S rDNA sequencing. The taxonomic similarities among the strains were analyzed using the simple matching ( S SM) and Jaccard ( S J) coefficients, and the UPGMA clustering algorithm. The phylogenetic position of the strains was inferred by the neighbor-joining method on the basis of the 16S rDNA sequences. All isolates were Gram-negative, facultatively methylotrophic, oxidase and catalase positive, and required no growth factors. Based on the results of numerical taxonomy, the strains formed four closely related clusters sharing ≥85% similarity. Analysis of the 16S rDNA sequences demonstrated that oxalotrophic, pink-pigmented, and facultatively methylotrophic strains could be identified as members of the genus Methylobacterium. Except for M. variabile and M. aquaticum, all of the Methylobacterium type strains tested had the ability of oxalate utilization. Our results indicate that the capability of oxalate utilization seems to be an uncommon trait and could be used as a valuable taxonomic criterion for differentiation of Methylobacterium species.

  8. Genome Sequence of Pseudomonas chlororaphis Strain 189.

    PubMed

    Town, Jennifer; Audy, Patrice; Boyetchko, Susan M; Dumonceaux, Tim J

    2016-06-23

    Pseudomonas chlororaphis strain 189 is a potent inhibitor of the growth of the potato pathogen Phytophthora infestans We determined the complete, finished sequence of the 6.8-Mbp genome of this strain, consisting of a single contiguous molecule. Strain 189 is closely related to previously sequenced strains of P. chlororaphis. Copyright © 2016 Town et al.

  9. Thermal stability of strained nanowires.

    PubMed

    Nisoli, Cristiano; Abraham, Douglas; Lookman, Turab; Saxena, Avadh

    2009-06-19

    Stranski-Krastanow strained islands undergo a shape anisotropy transition as they grow in size, finally evolving toward nanowires. This effect has been explained until now via simple energetic models that neglect thermodynamics. We investigate theoretically the stability of strained nanowires under thermal fluctuations of the long side. We find phase transitions from nanowires back to nanoislands as the temperature is increased and as the height of the nanostructure is raised or lowered, and we predict regions of phase coexistence. Our results are general, but explain recent data on the growth of erbium silicide on a vicinal Si surface.

  10. Characterization of strains of Corynebacterium bovis.

    PubMed Central

    Brooks, B W; Barnum, D A

    1984-01-01

    The biochemical and morphological characteristics of 104 strains of Corynebacterium bovis isolated from bovine milk samples and the C. bovis reference strain were found to be uniform. Valuable criteria for identification were presence of catalase and oxidase, production of acid from glucose and fructose and a requirement for enriched basal media. Six strains of human and three strains of bovine origin were found to be inconsistent with the reference strain. PMID:6722650

  11. Photoacoustic spectroscopy of Entamoeba histolytica strains

    NASA Astrophysics Data System (ADS)

    Acosta-Avalos, D.; Alvarado-Gil, J. J.; Silva, E. F.; Orozco, E.; de Menezes, L. F.; Vargas, H.

    2005-06-01

    Pathogenic and non-pathogenic strains of E. histolytica are studied using photoacoustic spectroscopy. It is shown that the pathogenic strain presents a spectrum similar to that of iron sulfur proteins. The non-pathogenic strain does not show any relevant absorption at the studied wavelength range. The differences observed between the optical absorption spectra of both strains opens the possibility of using photoacoustic spectroscopy as a reliable and simple technique to identify different types of E. histolytica strains.

  12. Bacteriocins and novel bacterial strains.

    USDA-ARS?s Scientific Manuscript database

    Poultry is thought to be a significant source of Campylobacter in human disease. We evaluated anti-Campylobacter activity among 365 Bacillus and Paenibacillus isolates from poultry. One novel antagonistic Bacillus circulans and three Paenibacillus polymyxa strains were identified and further studi...

  13. Trials with a Strain Gauge.

    ERIC Educational Resources Information Center

    Auty, Geoff

    1996-01-01

    Describes an attempt to match the goals of the practical demonstration of the use of a strain gauge and the technical applications of science and responding to student questions in early trials, while keeping within the level of electronics in advanced physics. (Author/JRH)

  14. Chronic occupational repetitive strain injury.

    PubMed

    O'Neil, B A; Forsythe, M E; Stanish, W D

    2001-02-01

    To review common repetitive strain injuries (RSIs) that occur in the workplace, emphasizing diagnosis, treatment, and etiology of these conditions. A MEDLINE search from January 1966 to June 1999 focused on articles published since 1990 because RSIs are relatively new diagnoses. MeSH headings that were explored using the thesaurus included "cumulative trauma disorder," "overuse injury," and "repetitive strain injury." The search was limited to English articles only, and preference was given to randomized controlled trials. Repetitive strain injuries result from repeated stress to the body's soft tissue structures including muscles, tendons, and nerves. They often occur in patients who perform repetitive movements either in their jobs or in extracurricular activities. Common RSIs include tendon-related disorders, such as rotator cuff tendonitis, and peripheral nerve entrapment disorders, such as carpal tunnel syndrome. A careful history and physical examination often lead to the diagnosis, but newer imaging techniques, such as magnetic resonance imaging and ultrasound, can help in refractory cases. Conservative management with medication, physiotherapy, or bracing is the mainstay of treatment. Surgery is reserved for cases that do not respond to treatment. Repetitive strain injury is common; primary care physicians must establish a diagnosis and, more importantly, its relationship to occupation. Treatment can be offered by family physicians who refer to specialists for cases refractory to conservative management.

  15. Chronic occupational repetitive strain injury.

    PubMed Central

    O'Neil, B. A.; Forsythe, M. E.; Stanish, W. D.

    2001-01-01

    OBJECTIVE: To review common repetitive strain injuries (RSIs) that occur in the workplace, emphasizing diagnosis, treatment, and etiology of these conditions. QUALITY OF EVIDENCE: A MEDLINE search from January 1966 to June 1999 focused on articles published since 1990 because RSIs are relatively new diagnoses. MeSH headings that were explored using the thesaurus included "cumulative trauma disorder," "overuse injury," and "repetitive strain injury." The search was limited to English articles only, and preference was given to randomized controlled trials. MAIN MESSAGE: Repetitive strain injuries result from repeated stress to the body's soft tissue structures including muscles, tendons, and nerves. They often occur in patients who perform repetitive movements either in their jobs or in extracurricular activities. Common RSIs include tendon-related disorders, such as rotator cuff tendonitis, and peripheral nerve entrapment disorders, such as carpal tunnel syndrome. A careful history and physical examination often lead to the diagnosis, but newer imaging techniques, such as magnetic resonance imaging and ultrasound, can help in refractory cases. Conservative management with medication, physiotherapy, or bracing is the mainstay of treatment. Surgery is reserved for cases that do not respond to treatment. CONCLUSION: Repetitive strain injury is common; primary care physicians must establish a diagnosis and, more importantly, its relationship to occupation. Treatment can be offered by family physicians who refer to specialists for cases refractory to conservative management. PMID:11228032

  16. Mobilomics in Saccharomyces cerevisiae strains

    PubMed Central

    2013-01-01

    Background Mobile Genetic Elements (MGEs) are selfish DNA integrated in the genomes. Their detection is mainly based on consensus–like searches by scanning the investigated genome against the sequence of an already identified MGE. Mobilomics aims at discovering all the MGEs in a genome and understanding their dynamic behavior: The data for this kind of investigation can be provided by comparative genomics of closely related organisms. The amount of data thus involved requires a strong computational effort, which should be alleviated. Results Our approach proposes to exploit the high similarity among homologous chromosomes of different strains of the same species, following a progressive comparative genomics philosophy. We introduce a software tool based on our new fast algorithm, called regender, which is able to identify the conserved regions between chromosomes. Our case study is represented by a unique recently available dataset of 39 different strains of S.cerevisiae, which regender is able to compare in few minutes. By exploring the non–conserved regions, where MGEs are mainly retrotransposons called Tys, and marking the candidate Tys based on their length, we are able to locate a priori and automatically all the already known Tys and map all the putative Tys in all the strains. The remaining putative mobile elements (PMEs) emerging from this intra–specific comparison are sharp markers of inter–specific evolution: indeed, many events of non–conservation among different yeast strains correspond to PMEs. A clustering based on the presence/absence of the candidate Tys in the strains suggests an evolutionary interconnection that is very similar to classic phylogenetic trees based on SNPs analysis, even though it is computed without using phylogenetic information. Conclusions The case study indicates that the proposed methodology brings two major advantages: (a) it does not require any template sequence for the wanted MGEs and (b) it can be applied to

  17. Material mechanical characterization method for multiple strains and strain rates

    SciTech Connect

    Erdmand, III, Donald L.; Kunc, Vlastimil; Simunovic, Srdjan; Wang, Yanli

    2016-01-19

    A specimen for measuring a material under multiple strains and strain rates. The specimen including a body having first and second ends and a gage region disposed between the first and second ends, wherein the body has a central, longitudinal axis passing through the first and second ends. The gage region includes a first gage section and a second gage section, wherein the first gage section defines a first cross-sectional area that is defined by a first plane that extends through the first gage section and is perpendicular to the central, longitudinal axis. The second gage section defines a second cross-sectional area that is defined by a second plane that extends through the second gage section and is perpendicular to the central, longitudinal axis and wherein the first cross-sectional area is different in size than the second cross-sectional area.

  18. High Strain, Strain Rate Behavior of PTFE/Al/W

    NASA Astrophysics Data System (ADS)

    Addiss, John; Cai, Jing; Walley, Steve; Proud, William; Nesterenko, Vitali

    2007-06-01

    Conventional dropweight technique was modified to accommodate low amplitude signals from low strength, cold isostatically pressed energetic ``heavy'' composites of polytetrafluoroethylene (PTFE)/AL/W. The fracture strength, strain and post-critical behaviour of fractured samples were measured for samples of different porosity and W grain size (the masses of each component being the same in each case). Unusual phenomenon of significantly higher strength (55 MPa) of porous composites (density 5.9 g/cc) with small tungsten particles (1 micron) in comparison with strength (32 MPa) of dense composites (7.1 g/cc) with larger tungsten particles (20 micron) was observed. This is attributed to force chains created by a network of small tungsten particles. Interrupted tests at the different level of strains revealed mechanism of fracture under dynamic compression.

  19. A NEW STRAIN OF TRANSMISSIBLE LEUCEMIA IN FOWLS (STRAIN H).

    PubMed

    Ellermann, V

    1921-03-31

    1. A new strain of fowl leucosis has been transmitted through twelve generations of fowls. 2. An increase in virulence was observed during its passage. This was shown in a shortening of the interval between inoculation and death. The increase in virulence does not affect the number of successful inoculations, which remains approximately constant in from 20 to 40 per cent of the birds employed. 3. As with former strains, the disease manifests itself in various forms; i.e., myeloid and intravascular lymphoid types. A single lymphatic case was observed. 4. In several intravascular cases a diminution in the hemolytic power of the serum was established. This phenomenon was absent in a number of myeloid cases. 5. Active immunization cannot be produced by means of the subcutaneous injection of virulent material. 6. The finding of previous experiments that the virus is filterable has been confirmed. 7. The inoculation of human leucemic material into fowls gave negative results.

  20. Strains

    MedlinePlus

    Pulled muscle ... can include: Pain and difficulty moving the injured muscle Discolored and bruised skin Swelling ... if you still have pain. Rest the pulled muscle for at least a day. If possible, keep ...

  1. Modelling to very high strains

    NASA Astrophysics Data System (ADS)

    Bons, P. D.; Jessell, M. W.; Griera, A.; Evans, L. A.; Wilson, C. J. L.

    2009-04-01

    Ductile strains in shear zones often reach extreme values, resulting in typical structures, such as winged porphyroclasts and several types of shear bands. The numerical simulation of the development of such structures has so far been inhibited by the low maximum strains that numerical models can normally achieve. Typical numerical models collapse at shear strains in the order of one to three. We have implemented a number of new functionalities in the numerical platform "Elle" (Jessell et al. 2001), which significantly increases the amount of strain that can be achieved and simultaneously reduces boundary effects that become increasingly disturbing at higher strain. Constant remeshing, while maintaining the polygonal phase regions, is the first step to avoid collapse of the finite-element grid required by finite-element solvers, such as Basil (Houseman et al. 2008). The second step is to apply a grain-growth routine to the boundaries of polygons that represent phase regions. This way, the development of sharp angles is avoided. A second advantage is that phase regions may merge or become separated (boudinage). Such topological changes are normally not possible in finite element deformation codes. The third step is the use of wrapping vertical model boundaries, with which optimal and unchanging model boundaries are maintained for the application of stress or velocity boundary conditions. The fourth step is to shift the model by a random amount in the vertical direction every time step. This way, the fixed horizontal boundary conditions are applied to different material points within the model every time step. Disturbing boundary effects are thus averaged out over the whole model and not localised to e.g. top and bottom of the model. Reduction of boundary effects has the additional advantage that model can be smaller and, therefore, numerically more efficient. Owing to the combination of these existing and new functionalities it is now possible to simulate the

  2. Virtual strain gage size study

    DOE PAGES

    Reu, Phillip L.

    2015-09-22

    DIC is a non-linear low-pass spatial filtering operation; whether we consider the effect of the subset and shape function, the strain window used in the strain calculation, of other post-processing of the results, each decision will impact the spatial resolution, of the measurement. More fundamentally, the speckle size limits, the spatial resolution by dictating the smallest possible subset. After this decision the processing settings are controlled by the allowable noise level balanced by possible bias errors created by the data filtering. This article describes a process to determine optimum DIC software settings to determine if the peak displacements or strainsmore » are being found.« less

  3. Strain tolerant microfilamentary superconducting wire

    DOEpatents

    Finnemore, Douglas K.; Miller, Theodore A.; Ostenson, Jerome E.; Schwartzkopf, Louis A.; Sanders, Steven C.

    1993-02-23

    A strain tolerant microfilamentary wire capable of carrying superconducting currents is provided comprising a plurality of discontinuous filaments formed from a high temperature superconducting material. The discontinuous filaments have a length at least several orders of magnitude greater than the filament diameter and are sufficiently strong while in an amorphous state to withstand compaction. A normal metal is interposed between and binds the discontinuous filaments to form a normal metal matrix capable of withstanding heat treatment for converting the filaments to a superconducting state. The geometry of the filaments within the normal metal matrix provides substantial filament-to-filament overlap, and the normal metal is sufficiently thin to allow supercurrent transfer between the overlapped discontinuous filaments but is also sufficiently thick to provide strain relief to the filaments.

  4. Strain softening in stretched DNA

    PubMed Central

    Luan, Binquan; Aksimentiev, Aleksei

    2010-01-01

    The microscopic mechanics of DNA stretching was characterized using extensive molecular dynamics simulations. By employing an anisotropic pressure control method, realistic force-extension dependences of effectively infinite DNA molecules were obtained. A coexistence of B- and S-DNA domains was observed during the overstretching transition. The simulations revealed that strain softening may occur in the process of stretching torsionally constrained DNA. The latter observation was qualitatively reconciled with available experimental data using a random-field Ising model. PMID:18851334

  5. Strain-Detecting Composite Materials

    NASA Technical Reports Server (NTRS)

    Wallace, Terryl A. (Inventor); Smith, Stephen W. (Inventor); Piascik, Robert S. (Inventor); Horne, Michael R. (Inventor); Messick, Peter L. (Inventor); Alexa, Joel A. (Inventor); Glaessgen, Edward H. (Inventor); Hailer, Benjamin T. (Inventor)

    2016-01-01

    A composite material includes a structural material and a shape-memory alloy embedded in the structural material. The shape-memory alloy changes crystallographic phase from austenite to martensite in response to a predefined critical macroscopic average strain of the composite material. In a second embodiment, the composite material includes a plurality of particles of a ferromagnetic shape-memory alloy embedded in the structural material. The ferromagnetic shape-memory alloy changes crystallographic phase from austenite to martensite and changes magnetic phase in response to the predefined critical macroscopic average strain of the composite material. A method of forming a composite material for sensing the predefined critical macroscopic average strain includes providing the shape-memory alloy having an austenite crystallographic phase, changing a size and shape of the shape-memory alloy to thereby form a plurality of particles, and combining the structural material and the particles at a temperature of from about 100-700.degree. C. to form the composite material.

  6. High temperature capacitive strain gage

    NASA Astrophysics Data System (ADS)

    Wnuk, Stephen P., Jr.; Wnuk, Stephen P., III; Wnuk, V. P.

    1990-01-01

    Capacitive strain gages designed for measurements in wind tunnels to 2000 F were built and evaluated. Two design approaches were followed. One approach was based on fixed capacitor plates with a movable ground plane inserted between the plates to effect differential capacitive output with strain. The second approach was based on movable capacitor plates suspended between sapphire bearings, housed in a rugged body, and arranged to operate as a differential capacitor. A sapphire bearing gage (1/4 in. diameter x 1 in. in size) was built with a range of 50,000 and a resolution of 200 microstrain. Apparent strain on Rene' 41 was less than + or - 1000 microstrain from room temperature to 2000 F. Three gage models were built from the Ground Plane Differential concept. The first was 1/4 in. square by 1/32 in. high and useable to 700 F. The second was 1/2 in. square by 1/16 in. high and useable to 1440 F. The third, also 1/2 in. square by 1/16 in. high was expected to operate in the 1600 to 2000 F range, but was not tested because time and funding ended.

  7. High Temperature Capacitive Strain Gage

    NASA Technical Reports Server (NTRS)

    Wnuk, Stephen P., Jr.; Wnuk, Stephen P., III; Wnuk, V. P.

    1990-01-01

    Capacitive strain gages designed for measurements in wind tunnels to 2000 F were built and evaluated. Two design approaches were followed. One approach was based on fixed capacitor plates with a movable ground plane inserted between the plates to effect differential capacitive output with strain. The second approach was based on movable capacitor plates suspended between sapphire bearings, housed in a rugged body, and arranged to operate as a differential capacitor. A sapphire bearing gage (1/4 in. diameter x 1 in. in size) was built with a range of 50,000 and a resolution of 200 microstrain. Apparent strain on Rene' 41 was less than + or - 1000 microstrain from room temperature to 2000 F. Three gage models were built from the Ground Plane Differential concept. The first was 1/4 in. square by 1/32 in. high and useable to 700 F. The second was 1/2 in. square by 1/16 in. high and useable to 1440 F. The third, also 1/2 in. square by 1/16 in. high was expected to operate in the 1600 to 2000 F range, but was not tested because time and funding ended.

  8. Yield strain in shear banding amorphous solids.

    PubMed

    Dasgupta, Ratul; Hentschel, H George E; Procaccia, Itamar

    2013-02-01

    In recent research it was found that the fundamental shear-localizing instability of amorphous solids under external strain, which eventually results in a shear band and failure, consists of a highly correlated array of Eshelby quadrupoles all having the same orientation and some density ρ. In this paper we calculate analytically the energy E(ρ,γ) associated with such highly correlated structures as a function of the density ρ and the external strain γ. We show that for strains smaller than a characteristic strain γ(Y) the total strain energy initially increases as the quadrupole density increases, but that for strains larger than γ(Y) the energy monotonically decreases with quadrupole density. We identify γ(Y) as the yield strain. Its value, derived from values of the qudrupole strength based on the atomistic model, agrees with that from the computed stress-strain curves and broadly with experimental results.

  9. Strains and Sprains Are a Pain

    MedlinePlus

    ... strain at some point. Strains and sprains are common injuries, especially for kids who are very active or ... such as twisting your ankle. This kind of injury is common in sports, but also can happen any time ...

  10. Strain Monitoring of Flexible Structures

    NASA Technical Reports Server (NTRS)

    Litteken, Douglas A.

    2017-01-01

    , such as tensile testing, fatigue testing, and shear testing, but common measurement techniques cannot be used on fabric. Measuring strain in a material and during a test is a critical parameter for an engineer to monitor the structure during the test and correlate to an analytical model. The ability to measure strain in fabric structures is a challenge for NASA. Foil strain gauges, for example, are commonplace on metallic structures testing, but are extremely difficult to interface with a fabric substrate. New strain measuring techniques need to be developed for use with fabric structures. This paper investigates options for measuring strain in fabric structures for both ground testing and in-space structural health monitoring. It evaluates current commercially available options and outlines development work underway to build custom measurement solutions for NASA's fabric structures.

  11. Turbulent Plane Wakes Subjected to Successive Strains

    NASA Technical Reports Server (NTRS)

    Rogers, Michael M.

    2003-01-01

    Six direct numerical simulations of turbulent time-evolving strained plane wakes have been examined to investigate the response of a wake to successive irrotational plane strains of opposite sign. The orientation of the applied strain field has been selected so that the flow is the time-developing analogue of a spatially developing wake evolving in the presence of either a favourable or an adverse streamwise pressure gradient. The magnitude of the applied strain rate a is constant in time t until the total strain e(sup at) reaches about four. At this point, a new simulation is begun with the sign of the applied strain being reversed (the original simulation is continued as well). When the total strain is reduced back to its original value of one, yet another simulation is begun with the sign of the strain being reversed again back to its original sign. This process is done for both initially "favourable" and initially "adverse" strains, providing simulations for each of these strain types from three different initial conditions. The evolution of the wake mean velocity deficit and width is found to be very similar for all the adversely strained cases, with both measures rapidly achieving exponential growth at the rate associated with the cross-stream expansive strain e(sup at). In the "favourably" strained cases, the wake widths approach a constant and the velocity deficits ultimately decay rapidly as e(sup -2at). Although all three of these cases do exhibit the same asymptotic exponential behaviour, the time required to achieve this is longer for the cases that have been previously adversely strained (by at approx. equals 1). These simulations confirm the generality of the conclusions drawn in Rogers (2002) regarding the response of plane wakes to strain. The evolution of strained wakes is not consistent with the predictions of classical self-similar analysis; a more general equilibrium similarity solution is required to describe the results. At least for the cases

  12. Using BEEM To Probe Strains In Semiconductors

    NASA Technical Reports Server (NTRS)

    Bell, L. Douglas; Milliken, Autumn M.; Manion, Stephen J.; Kaiser, William J.

    1996-01-01

    Ballistic-electron-emission microscopy (BEEM) useful in determining strains in semiconductors under some conditions. More specifically, BEEM is variant of scanning tunneling microscopy and sensitive to electronic structure of probed material. In present approach, BEEM used to obtain data on those aspects of variations in electronic structures related to variations in strains. Then by use of mathematical modeling of relationships between electronic structures and strains, variations in strains deduced from BEEM data.

  13. Temperature-Compensating Inactive Strain Gauge

    NASA Technical Reports Server (NTRS)

    Moore, Thomas C., Sr.

    1993-01-01

    Thermal contribution to output of active gauge canceled. High-temperature strain gauges include both active gauge wires sensing strains and inactive gauge wires providing compensation for thermal contributions to gauge readings. Inactive-gauge approach to temperature compensation applicable to commercially available resistance-type strain gauges operating at temperatures up to 700 degrees F and to developmental strain gauges operating at temperatures up to 2,000 degrees F.

  14. Optical Fibers Would Sense Local Strains

    NASA Technical Reports Server (NTRS)

    Egalon, Claudio O.; Rogowski, Robert S.

    1994-01-01

    Proposed fiber-optic transducers measure local strains. Includes lead-in and lead-out lengths producing no changes in phase shifts, plus short sensing length in which phase shift is sensitive to strain. Phase shifts in single-mode fibers vary with strains. In alternative version, multiple portions of optical fiber sensitive to strains characteristic of specific vibrational mode of object. Same principle also used with two-mode fiber.

  15. Using BEEM To Probe Strains In Semiconductors

    NASA Technical Reports Server (NTRS)

    Bell, L. Douglas; Milliken, Autumn M.; Manion, Stephen J.; Kaiser, William J.

    1996-01-01

    Ballistic-electron-emission microscopy (BEEM) useful in determining strains in semiconductors under some conditions. More specifically, BEEM is variant of scanning tunneling microscopy and sensitive to electronic structure of probed material. In present approach, BEEM used to obtain data on those aspects of variations in electronic structures related to variations in strains. Then by use of mathematical modeling of relationships between electronic structures and strains, variations in strains deduced from BEEM data.

  16. Piezoelectric field in strained GaAs.

    SciTech Connect

    Chow, Weng Wah; Wieczorek, Sebastian Maciej

    2005-11-01

    This report describes an investigation of the piezoelectric field in strained bulk GaAs. The bound charge distribution is calculated and suitable electrode configurations are proposed for (1) uniaxial and (2) biaxial strain. The screening of the piezoelectric field is studied for different impurity concentrations and sample lengths. Electric current due to the piezoelectric field is calculated for the cases of (1) fixed strain and (2) strain varying in time at a constant rate.

  17. Strain Rate Effects on Ultimate Strain of Copper

    DTIC Science & Technology

    1979-05-01

    34Dogbone" Specimen Used for Quasi-Static 5 and Intermediate Rate Tests 2 Schematic of Split Hopkinso’v Bar Apparatus 7 3a PETN Filled Tube Specimen...48 Experiment 25 Calculated Stress Components in Copper Cylinder 52 Expanded by PETN 26 Fracture of Explosively Expanded Cylindrical 54 Tube A-la...Record of Shot No. 10 73 A7b Framing Camera Record of Shot No. 10 74 A-8 Strain Versus Time for Copper Tube Expanded 75 by PETN vi

  18. Haemophilus ducreyi Cutaneous Ulcer Strains Are Nearly Identical to Class I Genital Ulcer Strains

    PubMed Central

    Gangaiah, Dharanesh; Webb, Kristen M.; Humphreys, Tricia L.; Fortney, Kate R.; Toh, Evelyn; Tai, Albert; Katz, Samantha S.; Pillay, Allan; Chen, Cheng-Yen; Roberts, Sally A.; Munson, Robert S.; Spinola, Stanley M.

    2015-01-01

    Background Although cutaneous ulcers (CU) in the tropics is frequently attributed to Treponema pallidum subspecies pertenue, the causative agent of yaws, Haemophilus ducreyi has emerged as a major cause of CU in yaws-endemic regions of the South Pacific islands and Africa. H. ducreyi is generally susceptible to macrolides, but CU strains persist after mass drug administration of azithromycin for yaws or trachoma. H. ducreyi also causes genital ulcers (GU) and was thought to be exclusively transmitted by microabrasions that occur during sex. In human volunteers, the GU strain 35000HP does not infect intact skin; wounds are required to initiate infection. These data led to several questions: Are CU strains a new variant of H. ducreyi or did they evolve from GU strains? Do CU strains contain additional genes that could allow them to infect intact skin? Are CU strains susceptible to azithromycin? Methodology/Principal Findings To address these questions, we performed whole-genome sequencing and antibiotic susceptibility testing of 5 CU strains obtained from Samoa and Vanuatu and 9 archived class I and class II GU strains. Except for single nucleotide polymorphisms, the CU strains were genetically almost identical to the class I strain 35000HP and had no additional genetic content. Phylogenetic analysis showed that class I and class II strains formed two separate clusters and CU strains evolved from class I strains. Class I strains diverged from class II strains ~1.95 million years ago (mya) and CU strains diverged from the class I strain 35000HP ~0.18 mya. CU and GU strains evolved under similar selection pressures. Like 35000HP, the CU strains were highly susceptible to antibiotics, including azithromycin. Conclusions/Significance These data suggest that CU strains are derivatives of class I strains that were not recognized until recently. These findings require confirmation by analysis of CU strains from other regions. PMID:26147869

  19. Acquisition of Dynamic Stress/Strain Data

    NASA Technical Reports Server (NTRS)

    Mines, R. G.; Demonet, R. J.

    1985-01-01

    Computer program enables real-time data acquisition and plotting of stress strain by small, desk top computer. Program monitors load cell and multiple-strain gages during tension or compression loading. Scan routine triggered by specified change of applied load or longitudinal strain.

  20. Job strain in physical therapists.

    PubMed

    Campo, Marc A; Weiser, Sherri; Koenig, Karen L

    2009-09-01

    Job stress has been associated with poor outcomes. In focus groups and small-sample surveys, physical therapists have reported high levels of job stress. Studies of job stress in physical therapy with larger samples are needed. The purposes of this study were: (1) to determine the levels of psychological job demands and job control reported by physical therapists in a national sample, (2) to compare those levels with national norms, and (3) to determine whether high demands, low control, or a combination of both (job strain) increases the risk for turnover or work-related pain. This was a prospective cohort study with a 1-year follow-up period. Participants were randomly selected members of the American Physical Therapy Association (n=882). Exposure assessments included the Job Content Questionnaire (JCQ), a commonly used instrument for evaluation of the psychosocial work environment. Outcomes included job turnover and work-related musculoskeletal disorders. Compared with national averages, the physical therapists reported moderate job demands and high levels of job control. About 16% of the therapists reported changing jobs during follow-up. Risk factors for turnover included high job demands, low job control, job strain, female sex, and younger age. More than one half of the therapists reported work-related pain. Risk factors for work-related pain included low job control and job strain. The JCQ measures only limited dimensions of the psychosocial work environment. All data were self-reported and subject to associated bias. Physical therapists' views of their work environments were positive, including moderate levels of demands and high levels of control. Those therapists with high levels of demands and low levels of control, however, were at increased risk for both turnover and work-related pain. Physical therapists should consider the psychosocial work environment, along with other factors, when choosing a job.

  1. Effect of strain and strain rate on residual microstructures in copper

    SciTech Connect

    Stevens, M.F.; Follansbee, P.S.

    1986-01-01

    Several specimens of OFE Cu were deformed in compression to study the resulting microstructures at equivalent levels of threshold stress and strain. Equiaxed, diffuse dislocation cells are more persistent in Cu when tested at strain rates exceeding 10/sup 3/ sec/sup -1/. At quasi-static strain rates, dislocation collapse into more distinct, narrow microbands occurs at lower strain levels.

  2. Radio-Frequency Strain Monitor

    NASA Technical Reports Server (NTRS)

    Heyman, Joseph S.; Rogowski, Robert S.; Holben, Milford S., Jr.

    1988-01-01

    Radio-frequency (RF) strain monitor developed to measure lengths of objects. RF waveguide or cable bonded to structure monitored. Propagation of RF signal along waveguide results in phase shift proportional to length of path traveled. Impedance mismatches placed in RF cable at nodes of structure. Records mismatches and detects overall length of line and lengths of intervals between nodes. Used to detect changes in elements of large structure with single cable. Monitor has potential for many applications, including monitoring stability of such large structures as aircraft, bridges, and buildings in Earthquake zones.

  3. Tests of strain analysis by experimental deformation

    NASA Astrophysics Data System (ADS)

    Borradaile, G. J.; McArthur, J.

    1991-01-01

    The linearisation method and Robin's method of strain analysis of granular materials yield accurate strain estimates for a variety of materials deformed experimentally in pure shear. The breakdown of continuum behaviour at high pore fluid pressures causes the methods to overestimate the strain because they do not take added rigid-body rotation into account. Both methods tolerate some variation in initial shape ratio and some degree of initial preferred orientation at modest strains. Results of tests on polymict sandstone indicate that the lower than average ductility of competent clasts may be balanced against an unfavourable degree of preferred orientation to yield an improved strain estimate.

  4. Error quantification in strain mapping methods.

    PubMed

    Guerrero, Elisa; Galindo, Pedro; Yáñez, Andrés; Ben, Teresa; Molina, Sergio I

    2007-10-01

    In this article a method for determining errors of the strain values when applying strain mapping techniques has been devised. This methodology starts with the generation of a thickness/defocus series of simulated high-resolution transmission electron microscopy images of InAsxP1-x/InP heterostructures and the application of geometric phase. To obtain optimal defocusing conditions, a comparison of different defocus values is carried out by the calculation of the strain profile standard deviations among different specimen thicknesses. Finally, based on the analogy of real state strain to a step response, a characterization of strain mapping error near an interface is proposed.

  5. Demonstration test of burner liner strain measurements using resistance strain gages

    NASA Technical Reports Server (NTRS)

    Grant, H. P.; Anderson, W. L.

    1984-01-01

    A demonstration test of burner liner strain measurements using resistance strain gages as well as a feasibility test of an optical speckle technique for strain measurement are presented. The strain gage results are reported. Ten Kanthal A-1 wire strain gages were used for low cycle fatigue strain measurements to 950 K and .002 apparent strain on a JT12D burner can in a high pressure (10 atmospheres) burner test. The procedure for use of the strain gages involved extensive precalibration and postcalibration to correct for cooling rate dependence, drift, and temperature effects. Results were repeatable within + or - .0002 to .0006 strain, with best results during fast decels from 950 K. The results agreed with analytical prediction based on an axisymmetric burner model, and results indicated a non-uniform circumferential distribution of axial strain, suggesting temperature streaking.

  6. Strain engineering of graphene: a review.

    PubMed

    Si, Chen; Sun, Zhimei; Liu, Feng

    2016-02-14

    Graphene has intrigued the science community by many unique properties not found in conventional materials. In particular, it is the strongest two-dimensional material ever measured, being able to sustain reversible tensile elastic strain larger than 20%, which yields an interesting possibility to tune the properties of graphene by strain and thus opens a new field called "straintronics". In this article, the current progress in the strain engineering of graphene is reviewed. We first summarize the strain effects on the electronic structure and Raman spectra of graphene. We then highlight the electron-phonon coupling greatly enhanced by the biaxial strain and the strong pseudomagnetic field induced by the non-uniform strain with specific distribution. Finally, the potential application of strain-engineering in the self-assembly of foreign atoms on the graphene surface is also discussed. Given the short history of graphene straintronics research, the current progress has been notable, and many further advances in this field are expected.

  7. Fundamental understanding of piezoelectric strain sensors

    NASA Astrophysics Data System (ADS)

    Sirohi, Jayant; Chopra, Inderjit

    1999-06-01

    This paper investigates the behavior of piezoelectric elements as strain sensors. Strain is measured in terms of the charge generated by the element as a result of the direct piezoelectric effect. Strains from piezoceramic and piezofilm sensors are compared with strains from a conventional foil strain gage and the advantages of each type of sensor are discussed, along with their limitations. The sensors are surface bonded and are calibrated by means of a dynamic beam bending setup over a frequency range of 5 - 500 Hz. Correction factors to account for transverse strain and shear lag effects due to the bond layer are analytically derived and validated experimentally. Additionally, design of signal conditioning electronics to collect the signals from the piezoelectric sensors is addressed. The superior performance of piezoelectric sensors compared to conventional strain gages in terms of sensitivity and signal to noise ratio is demonstrated.

  8. Strain engineering of graphene: a review

    NASA Astrophysics Data System (ADS)

    Si, Chen; Sun, Zhimei; Liu, Feng

    2016-02-01

    Graphene has intrigued the science community by many unique properties not found in conventional materials. In particular, it is the strongest two-dimensional material ever measured, being able to sustain reversible tensile elastic strain larger than 20%, which yields an interesting possibility to tune the properties of graphene by strain and thus opens a new field called ``straintronics''. In this article, the current progress in the strain engineering of graphene is reviewed. We first summarize the strain effects on the electronic structure and Raman spectra of graphene. We then highlight the electron-phonon coupling greatly enhanced by the biaxial strain and the strong pseudomagnetic field induced by the non-uniform strain with specific distribution. Finally, the potential application of strain-engineering in the self-assembly of foreign atoms on the graphene surface is also discussed. Given the short history of graphene straintronics research, the current progress has been notable, and many further advances in this field are expected.

  9. Comparison of strains of Mycoplasma iowae.

    PubMed

    Rhoades, K R

    1984-01-01

    Comparison of biochemical test results and protein electrophoretic patterns of 21 strains of Mycoplasma iowae indicated that all were similar. Comparison of agglutination test results indicated marked within-species antigenic variation. None of 21 antigens prepared from different strains were effective in demonstrating turkey antibody against five reference strains. Examination of sera from turkeys exposed by intra-air-sac inoculation to two pathogenic strains also indicated antigenic variation. Neither the M. iowae type-strain, Iowa 695, nor the other reference strains were effective in demonstrating antibody against both strains used to expose the turkeys. These findings suggest that antigenic variation may be a major problem in effective serodiagnosis of M. iowae infections.

  10. Ignition Delay Associated with a Strained Strip

    NASA Technical Reports Server (NTRS)

    Gerk, T. J.; Karagozian, A. R.

    1996-01-01

    Ignition processes associated with two adjacent fuel-oxidizer interferences bounding a strained fuel strip are explored here using single-step activation energy asymptotics. Calculations are made for constant as well as temporally decaying strain fields. There possible models of ignition are determined: one in which the two interfaces ignite independently as diffusion flames; one in which the two interfaces ignite dependently and in which ignition occurs to form a single , premixed flame at very high strain rates before ignition is completely prevented. In contrast to a single, isolated interface in which ignition can be prevented by overmatching heat production with heat convection due to strain, ignition of a strained fuel strip can also be prevented if the finite extend of fuel is diluted by oxidizer more quickly than heat production can cause a positive feedback thermal runaway. These behaviors are dependent on the relative sizes of timescales associated with species and heat diffusion, with convection due to strain, and with the chemical reaction. The result here indicate that adjacent, strained species interfaces may ignite quite differently in nature from ignition of a single, strained intrface and that their interdependence should be considered as the interfaces are brought closer together in complex strain fields. Critical strain rates leading to complete ignition delay are found to be considerably smaller for the fuel strip than those for single interfaces as the fuel strip is made thin in comparison to diffusion and chemical length scales.

  11. Multiplicative earthquake likelihood models incorporating strain rates

    NASA Astrophysics Data System (ADS)

    Rhoades, D. A.; Christophersen, A.; Gerstenberger, M. C.

    2017-01-01

    SUMMARYWe examine the potential for <span class="hlt">strain</span>-rate variables to improve long-term earthquake likelihood models. We derive a set of multiplicative hybrid earthquake likelihood models in which cell rates in a spatially uniform baseline model are scaled using combinations of covariates derived from earthquake catalogue data, fault data, and <span class="hlt">strain</span>-rates for the New Zealand region. Three components of the <span class="hlt">strain</span> rate estimated from GPS data over the period 1991-2011 are considered: the shear, rotational and dilatational <span class="hlt">strain</span> rates. The hybrid model parameters are optimised for earthquakes of M 5 and greater over the period 1987-2006 and tested on earthquakes from the period 2012-2015, which is independent of the <span class="hlt">strain</span> rate estimates. The shear <span class="hlt">strain</span> rate is overall the most informative individual covariate, as indicated by Molchan error diagrams as well as multiplicative modelling. Most models including <span class="hlt">strain</span> rates are significantly more informative than the best models excluding <span class="hlt">strain</span> rates in both the fitting and testing period. A hybrid that combines the shear and dilatational <span class="hlt">strain</span> rates with a smoothed seismicity covariate is the most informative model in the fitting period, and a simpler model without the dilatational <span class="hlt">strain</span> rate is the most informative in the testing period. These results have implications for probabilistic seismic hazard analysis and can be used to improve the background model component of medium-term and short-term earthquake forecasting models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4222745','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4222745"><span>Distribution of Nontuberculous Mycobacteria <span class="hlt">strains</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2013-01-01</p> <p>Aim Mycobacteria other than tuberculosis (MOTT) cause increasingly serious infections especially in immunosuppressive patients by direct transmission from the environment or after colonization. However, identification of these species is difficult because of the cost and difficulties in defining to species level. Identification and distribution of these species can help clinician in the choice of treatment. Materials and methods A total of 90 MOTT <span class="hlt">strains</span> obtained from four different centers were included in the study. These <span class="hlt">strains</span> were identified by sequence analysis of 16S rRNA and Hsp65 genetic regions. Results Accordingly, within the 90 MOTT <span class="hlt">strains</span>, 17 different species were identified. In order of frequency, these species were M. gordonea (n = 21), M. abscessus (n = 13), M. lentiflavum (n = 9), M. fortuitum (n = 8), M. intracellulare (n = 6), M. kumamotonense (n = 6), M. neoaurum (n = 5), M. chimaera (n = 5), M. alvei (n = 5), M. peregrinum (n = 3), M. canariasense (n = 3), M. flavescens (n = 1), M. mucogenicum (n = 1), M. chelona (n = 1), M. elephantis (n = 1), M. terrae (n = 1) and M. xenopi (n = 1). Most frequently identified MOTT species according to the geographical origin were as follows: M. abscessus was the most common species either in Istanbul or Malatya regions (n = 6, n = 6, consequently). While M. kumamotonense was the most frequent species isolated from Ankara region (n = 6), M. gordonea was the most common for Samsun region (n = 14). Conclusion Our study revealed that frequency of MOTT varies depending on the number of clinical samples and that frequency of these species were affected by the newly identified species as a result of the use of novel molecular methods. In conclusion, when establishing diagnosis and treatment methods, it is important to know that infections caused by unidentified MOTT species may vary according to the regions in Turkey. The results</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25503536','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25503536"><span><span class="hlt">Strain</span> effects on oxygen migration in perovskites.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mayeshiba, Tam; Morgan, Dane</p> <p>2015-01-28</p> <p>Fast oxygen transport materials are necessary for a range of technologies, including efficient and cost-effective solid oxide fuel cells, gas separation membranes, oxygen sensors, chemical looping devices, and memristors. <span class="hlt">Strain</span> is often proposed as a method to enhance the performance of oxygen transport materials, but the magnitude of its effect and its underlying mechanisms are not well-understood, particularly in the widely-used perovskite-structured oxygen conductors. This work reports on an ab initio prediction of <span class="hlt">strain</span> effects on migration energetics for nine perovskite systems of the form LaBO3, where B = [Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Ga]. Biaxial <span class="hlt">strain</span>, as might be easily produced in epitaxial systems, is predicted to lead to approximately linear changes in migration energy. We find that tensile biaxial <span class="hlt">strain</span> reduces the oxygen vacancy migration barrier across the systems studied by an average of 66 meV per percent <span class="hlt">strain</span> for a single selected hop, with a low of 36 and a high of 89 meV decrease in migration barrier per percent <span class="hlt">strain</span> across all systems. The estimated range for the change in migration barrier within each system is ±25 meV per percent <span class="hlt">strain</span> when considering all hops. These results suggest that <span class="hlt">strain</span> can significantly impact transport in these materials, e.g., a 2% tensile <span class="hlt">strain</span> can increase the diffusion coefficient by about three orders of magnitude at 300 K (one order of magnitude at 500 °C or 773 K) for one of the most <span class="hlt">strain</span>-responsive materials calculated here (LaCrO3). We show that a simple elasticity model, which assumes only dilative or compressive <span class="hlt">strain</span> in a cubic environment and a fixed migration volume, can qualitatively but not quantitatively model the <span class="hlt">strain</span> dependence of the migration energy, suggesting that factors not captured by continuum elasticity play a significant role in the <span class="hlt">strain</span> response.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/892605','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/892605"><span>Determining Micromechanical <span class="hlt">Strain</span> in Nitinol</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Strasberg, Matthew; /SLAC</p> <p>2006-09-27</p> <p>Nitinol is a superelastic alloy made of equal parts nickel and titanium. Due to its unique shape memory properties, nitinol is used to make medical stents, lifesaving devices used to allow blood flow in occluded arteries. Micromechanical models and even nitinol-specific finite element analysis (FEA) software are insufficient for unerringly predicting fatigue and resultant failure. Due to the sensitive nature of its application, a better understanding of nitinol on a granular scale is being pursued through X-ray diffraction techniques at the Stanford Synchrotron Radiation Laboratory (SSRL) at the Stanford Linear Accelerator Center (SLAC). Through analysis of powder diffraction patterns of nitinol under increasing tensile loads, localized <span class="hlt">strain</span> can be calculated. We compare these results with micromechanical predictions in order to advance nitinol-relevant FEA tools. From this we hope to gain a greater understanding of how nitinol fatigues under multi-axial loads.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AIPC.1723b0001D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AIPC.1723b0001D"><span>Modeling competition between yeast <span class="hlt">strains</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Gee, Maarten; van Mourik, Hilda; de Visser, Arjan; Molenaar, Jaap</p> <p>2016-04-01</p> <p>We investigate toxin interference competition between S. cerevisiae colonies grown on a solid medium. In vivo experiments show that the outcome of this competition depends strongly on nutrient availability and cell densities. Here we present a new model for S. cerevisiae colonies, calculating the local height and composition of the colonies. The model simulates yeast colonies that show a good fit to experimental data. Simulations of colonies that start out with a homogeneous mixture of toxin producing and toxin sensitive cells can display remarkable pattern formation, depending on the initial ratio of the <span class="hlt">strains</span>. Simulations in which the toxin producing and toxin sensitive species start at nearby positions clearly show that toxin production is advantageous.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26902321','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26902321"><span>Comparison of <span class="hlt">Strain</span> Rosettes and Digital Image Correlation for Measuring Vertebral Body <span class="hlt">Strain</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gustafson, Hannah; Siegmund, Gunter; Cripton, Peter</p> <p>2016-05-01</p> <p><span class="hlt">Strain</span> gages are commonly used to measure bone <span class="hlt">strain</span>, but only provide <span class="hlt">strain</span> at a single location. Digital image correlation (DIC) is an optical technique that provides the displacement, and therefore <span class="hlt">strain</span>, over an entire region of interest on the bone surface. This study compares vertebral body <span class="hlt">strains</span> measured using <span class="hlt">strain</span> gages and DIC. The anterior surfaces of 15 cadaveric porcine vertebrae were prepared with a <span class="hlt">strain</span> rosette and a speckled paint pattern for DIC. The vertebrae were loaded in compression with a materials testing machine, and two high-resolution cameras were used to image the anterior surface of the bones. The mean noise levels for the <span class="hlt">strain</span> rosette and DIC were 1 με and 24 με, respectively. Bland-Altman analysis was used to compare <span class="hlt">strain</span> from the DIC and rosette (excluding 44% of trials with some evidence of <span class="hlt">strain</span> rosette failure or debonding); the mean difference ± 2 standard deviations (SDs) was -108 με ± 702 με for the minimum (compressive) principal <span class="hlt">strain</span> and -53 με ± 332 με for the maximum (tensile) principal <span class="hlt">strain</span>. Although the DIC has higher noise, it avoids the relatively high risk we observed of <span class="hlt">strain</span> gage debonding. These results can be used to develop guidelines for selecting a method to measure <span class="hlt">strain</span> on bone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3714661','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3714661"><span>Sensor for Measuring <span class="hlt">Strain</span> in Textile</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mattmann, Corinne; Clemens, Frank; Tröster, Gerhard</p> <p>2008-01-01</p> <p>In this paper a stain sensor to measure large <span class="hlt">strain</span> (80%) in textiles is presented. It consists of a mixture of 50wt-% thermoplastic elastomer (TPE) and 50wt-% carbon black particles and is fiber-shaped with a diameter of 0.315mm. The attachment of the sensor to the textile is realized using a silicone film. This sensor configuration was characterized using a <span class="hlt">strain</span> tester and measuring the resistance (extension-retraction cycles): It showed a linear resistance response to <span class="hlt">strain</span>, a small hysteresis, no ageing effects and a small dependance on the <span class="hlt">strain</span> velocity. The total mean error caused by all these effects was ±5.5% in <span class="hlt">strain</span>. Washing several times in a conventional washing machine did not influence the sensor properties. The paper finishes by showing an example application where 21 <span class="hlt">strain</span> sensors were integrated into a catsuit. With this garment, 27 upper body postures could be recognized with an accuracy of 97%. PMID:27879904</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/9891143','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/9891143"><span>Job <span class="hlt">Strain</span> in Shift and Daytime Workers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Knutsson; Nilsson</p> <p>1997-07-01</p> <p>Cross-sectional questionnaire data were used to compare the levels of job <span class="hlt">strain</span> in shift and daytime workers. Job <span class="hlt">strain</span> was measured according to Karasek's Demands/Discretion model. Four occupational groups were included: drivers, industrial workers, policemen/watchmen, and cooks. The study subjects were a random sample of 508 daytime workers and 418 shift workers. Job demand did not differentiate between shift and daytime workers, comparing groups broken down by gender and by occupation. The daytime workers reported higher levels of job <span class="hlt">strain</span> than the shift workers, and women experienced a higher level of job <span class="hlt">strain</span> than did men. Multiple linear regression analysis showed that only occupational group and gender predicted job <span class="hlt">strain</span> level. Shiftwork was not significantly associated with job <span class="hlt">strain</span> in the regression model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24518385','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24518385"><span>The many shades of prion <span class="hlt">strain</span> adaptation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Baskakov, Ilia V</p> <p>2014-01-01</p> <p>In several recent studies transmissible prion disease was induced in animals by inoculation with recombinant prion protein amyloid fibrils produced in vitro. Serial transmission of amyloid fibrils gave rise to a new class of prion <span class="hlt">strains</span> of synthetic origin. Gradual transformation of disease phenotypes and PrP(Sc) properties was observed during serial transmission of synthetic prions, a process that resembled the phenomenon of prion <span class="hlt">strain</span> adaptation. The current article discusses the remarkable parallels between phenomena of prion <span class="hlt">strain</span> adaptation that accompanies cross-species transmission and the evolution of synthetic prions occurring within the same host. Two alternative mechanisms underlying prion <span class="hlt">strain</span> adaptation and synthetic <span class="hlt">strain</span> evolution are discussed. The current article highlights the complexity of the prion transmission barrier and <span class="hlt">strain</span> adaptation and proposes that the phenomenon of prion adaptation is more common than previously thought.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19840000339&hterms=vibrational+modes&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dvibrational%2Bmodes','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19840000339&hterms=vibrational+modes&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dvibrational%2Bmodes"><span>Deriving <span class="hlt">Strain</span> Modes From Vibrational Tests</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Young, J. W.; Joanides, J. C.</p> <p>1985-01-01</p> <p>Measurements and theoretical analysis complement each other. Experimental acceleration and <span class="hlt">strain</span> data used to calculate coefficients of low-frequency vibrational modes of object under test. An iterative comparison of experimental and calculated <span class="hlt">strains</span> give modal model of improved accuracy that predicts <span class="hlt">strains</span> under operating conditions. Method useful in fatigue life and reliability analyses of buildings, pumps, engines, vehicles, and other systems subject to vibrations and loud noises during operation.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA571154','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA571154"><span>SNIT: SNP Identification for <span class="hlt">Strain</span> Typing</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2011-01-01</p> <p>Durkin S, Schneewind O, Nierman WC: Genome sequencing and analysis of Yersina pestis KIM D27, an avirulent <span class="hlt">strain</span> exempt from select agent regulation. PLoS...gener- ated from next-generation sequencing (NGS) data, we selected the recently published Yersinia pestis KIM D27 genome [12]. The Y. pestis D27 <span class="hlt">strain</span>...is a deriva- tive of Y. pestis KIM 10 <span class="hlt">strain</span> (accession no. NC_004088). The Y. pestis KIM D27 draft genome (accession no. ADDC00000000) was generated</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010TePhL..36..507B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010TePhL..36..507B"><span>On inhomogeneous <span class="hlt">straining</span> in compressed sylvinite</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barannikova, S. A.; Nadezhkin, M. V.; Zuev, L. B.; Zhigalkin, V. M.</p> <p>2010-06-01</p> <p>Spatiotemporal distributions of local components of the distortion tensor of quasi-plastic materials—saliferous rocks (sylvinite)—have been studied under active compressive <span class="hlt">straining</span> conditions using double-exposure speckle photography techniques. The <span class="hlt">strain</span> localization patterns are presented and the features of macroscopic <span class="hlt">strain</span> inhomogeneity are considered for inelastic behavior of the material. Results obtained for the slow wave processes in deformed saliferous rocks are compared to analogous data available for ionic crystals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002SPIE.4700..304A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002SPIE.4700..304A"><span>Microminiature temperature-compensated magnetoelastic <span class="hlt">strain</span> gauge</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arms, Steven W.; Townsend, Christopher P.</p> <p>2002-07-01</p> <p>Our objective was to demonstrate a microminiature magnetoelastic <span class="hlt">strain</span> gauge that provides both <span class="hlt">strain</span> and temperature signals without additional sensors. Iron based magnetoelastic materials were embedded within superelastic nickel/titanium (NiTi) tubing. NiTi stress was transferred to the ferrite, causing a permeability change sensed by a tiny coil. The coil/bridge was excited (70 KHz AC), synchronously demodulated, and amplified to produce a voltage output proportional to coil/ferrite impedance. A DC voltage was also applied and separately conditioned to provide an output proportional to coil resistance; this signal was used to provide thermal compensation. Controlled <span class="hlt">strains</span> were applied and 6 Hz cyclic outputs recorded simultaneously from the magnetoelastic <span class="hlt">strain</span> gauge and conventional foil <span class="hlt">strain</span> gauges. The magnetoelastic <span class="hlt">strain</span> gauge tracked the foil gauge with minimal hysteresis and good linearity over 600 microstrain; repeatability was approximately 1.5 microstrain. The magnetoelastic <span class="hlt">strain</span> gauge's gauge factor was computed from delta inductance/original inductance under static <span class="hlt">strain</span> conditions. Temperatures of 25-140 deg C resulted in an uncompensated shift of 15 microstrain/deg C, and compensated shift of 1.0 microstrain/deg C. A sensitive micro-magnetoelastic <span class="hlt">strain</span> gauge was demonstrated using the same sensor to detect stress and temperature with no moving parts, high gauge factor, and good thermal stability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MsT.........54S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MsT.........54S"><span>Construction of an Optical Fiber <span class="hlt">Strain</span> Gauge</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sulaiman, Najwa</p> <p></p> <p>This project is focused on the construction of an optical fiber <span class="hlt">strain</span> gauge that is based on a <span class="hlt">strain</span> gauge described by Butter and Hocker. Our gauge is designed to generate an interference pattern from the signals carried on two bare single-mode fibers that are fastened to an aluminum cantilever. When the cantilever experiences flexural stress, the interference pattern should change. By observing this change, it is possible to determine the <span class="hlt">strain</span> experienced by the cantilever. I describe the design and construction of our optical fiber <span class="hlt">strain</span> gauge as well as the characterization of different parts of the apparatus.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/912475','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/912475"><span>Measurement of Sorption-Induced <span class="hlt">Strain</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Eric P. Robertson; Richard L. Christiansen</p> <p>2005-05-01</p> <p><span class="hlt">Strain</span> caused by the adsorption of gases was measured in samples of subbituminous coal from the Powder River basin of Wyoming, U.S.A. and high-volatile bituminous coal from east-central Utah, U.S.A. using an apparatus developed jointly at the Idaho National Laboratory (Idaho Falls, Idaho, U.S.A.) and Colorado School of Mines (Golden, Colorado, U.S.A.). The apparatus can be used to measure <span class="hlt">strain</span> on multiple small coal samples based on the optical detection of the longitudinal <span class="hlt">strain</span> instead of the more common usage of <span class="hlt">strain</span> gauges, which require larger samples and longer equilibration times. With this apparatus, we showed that the swelling and shrinkage processes were reversible and that accurate <span class="hlt">strain</span> data could be obtained in a shortened amount of time. A suite of <span class="hlt">strain</span> curves was generated for these coals using gases that included carbon dioxide, nitrogen, methane, helium, and various mixtures of these gases. A Langmuir-type equation was applied to satisfactorily model the <span class="hlt">strain</span> data obtained for pure gases. The sorption-induced <span class="hlt">strain</span> measured in the subbituminous coal was larger than the high-volatile bituminous coal for all gases tested over the range of pressures used in the experimentation, with the CO2-induced <span class="hlt">strain</span> for the subbituminous coal over twice as great at the bituminous coal.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AcMSn..29..543X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AcMSn..29..543X"><span>Control of surface wettability via <span class="hlt">strain</span> engineering</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xiong, Wei; Liu, Jefferson Zhe; Zhang, Zhi-Liang; Zhen, Quan-Shui</p> <p>2013-08-01</p> <p>Reversible control of surface wettability has wide applications in lab-on-chip systems, tunable optical lenses, and microfluidic tools. Using a graphene sheet as a sample material and molecular dynamic simulations, we demonstrate that <span class="hlt">strain</span> engineering can serve as an effective way to control the surface wettability. The contact angles θ of water droplets on a graphene vary from 72.5° to 106° under biaxial <span class="hlt">strains</span> ranging from -10% to 10% that are applied on the graphene layer. For an intrinsic hydrophilic surface (at zero <span class="hlt">strain</span>), the variation of θ upon the applied <span class="hlt">strains</span> is more sensitive, i.e., from 0° to 74.8°. Overall the cosines of the contact angles exhibit a linear relation with respect to the <span class="hlt">strains</span>. In light of the inherent dependence of the contact angle on liquid-solid interfacial energy, we develop an analytic model to show the cos θ as a linear function of the adsorption energy E ads of a single water molecule over the substrate surface. This model agrees with our molecular dynamic results very well. Together with the linear dependence of E ads on biaxial <span class="hlt">strains</span>, we can thus understand the effect of <span class="hlt">strains</span> on the surface wettability. Thanks to the ease of reversibly applying mechanical <span class="hlt">strains</span> in micro/nano-electromechanical systems, we believe that <span class="hlt">strain</span> engineering can be a promising means to achieve the reversibly control of surface wettability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15004343','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15004343"><span>Caregiver role <span class="hlt">strain</span> of older workers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Beitman, Candace L; Johnson, Jennifer L; Clark, Adrienne L; Highsmith, Sharon R; Burgess, Amy L; Minor, Megan C; Stir, Aimee L</p> <p>2004-01-01</p> <p>The purpose of this study was to measure role <span class="hlt">strain</span> in older adult workers who were also caregivers of frail elders according to Komarovsky's role <span class="hlt">strain</span> theory, and to determine whether different patterns of role <span class="hlt">strain</span> exist for male worker-caregivers than females. Researchers developed the Job-Caregiver Role <span class="hlt">Strain</span> Scale Survey, which was adapted from a survey that measured role <span class="hlt">strain</span> in working parents and spouses. Surveys were distributed to 11 male and 34 female older workers who were also caregivers. A factor analysis was completed, which isolated four factors of role <span class="hlt">strain</span>. Researchers named the factors time management and arrangements, health and competing role demands, low rewards, and reactions to perceptions. Role <span class="hlt">strain</span> in older adult worker-caregivers is complex and involves multiple variables. A discriminant function analysis predicted differences in the way older male and female worker-caregivers perceived role <span class="hlt">strain</span>. Use of role <span class="hlt">strain</span> theory can assist employers and occupational therapists in developing and maintaining work environments that support not only the older employee's work performance, but participation in the role of elder caregiver as well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4644690','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4644690"><span>Skeletal muscle tensile <span class="hlt">strain</span> dependence: hyperviscoelastic nonlinearity</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wheatley, Benjamin B; Morrow, Duane A; Odegard, Gregory M; Kaufman, Kenton R; Donahue, Tammy L Haut</p> <p>2015-01-01</p> <p>Introduction Computational modeling of skeletal muscle requires characterization at the tissue level. While most skeletal muscle studies focus on hyperelasticity, the goal of this study was to examine and model the nonlinear behavior of both time-independent and time-dependent properties of skeletal muscle as a function of <span class="hlt">strain</span>. Materials and Methods Nine tibialis anterior muscles from New Zealand White rabbits were subject to five consecutive stress relaxation cycles of roughly 3% <span class="hlt">strain</span>. Individual relaxation steps were fit with a three-term linear Prony series. Prony series coefficients and relaxation ratio were assessed for <span class="hlt">strain</span> dependence using a general linear statistical model. A fully nonlinear constitutive model was employed to capture the <span class="hlt">strain</span> dependence of both the viscoelastic and instantaneous components. Results Instantaneous modulus (p<0.0005) and mid-range relaxation (p<0.0005) increased significantly with <span class="hlt">strain</span> level, while relaxation at longer time periods decreased with <span class="hlt">strain</span> (p<0.0005). Time constants and overall relaxation ratio did not change with <span class="hlt">strain</span> level (p>0.1). Additionally, the fully nonlinear hyperviscoelastic constitutive model provided an excellent fit to experimental data, while other models which included linear components failed to capture muscle function as accurately. Conclusions Material properties of skeletal muscle are <span class="hlt">strain</span>-dependent at the tissue level. This <span class="hlt">strain</span> dependence can be included in computational models of skeletal muscle performance with a fully nonlinear hyperviscoelastic model. PMID:26409235</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/366503','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/366503"><span>Investigation of a noncontact <span class="hlt">strain</span> measurement technique</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Damiano, B.; Talarico, L.J.</p> <p>1996-05-01</p> <p>The goal of this project was to investigate the feasibility of a new noncontact technique for directly and continuously monitoring peak <span class="hlt">strain</span> in rotating components. The technique utilizes the unique <span class="hlt">strain</span>-sensitive magnetic material properties of transformation Induced Plasticity (TRIP) steel alloys to measure <span class="hlt">strain</span>. These alloys are weakly magnetic when unstrained but become strongly ferromagnetic after mechanical deformation. A computer study was performed to determine whether the <span class="hlt">strain</span>-induced change in the magnetic material properties of a TRIP steel gage bonded to a rotating component would cause significant perturbations in the magnetic flux of a stationary electromagnet. The effects of <span class="hlt">strain</span> level, distance between the rotating component and the stationary electromagnet, and motion-induced eddy currents on flux perturbation magnitude were investigated. The calculated results indicate that a TRIP steel <span class="hlt">strain</span> sensing element can cause a significant perturbation in the magnetic flux of a stationary electromagnet. The magnetic flux perturbation magnitude was found to be inversely proportional to the distance between the magnet face and the TRIP steel element and directly proportional to the TRIP steel <span class="hlt">strain</span> level. The effect of motion-induced eddy currents on the magnetic flux was found to be negligible. It appears that the technique can be successfully applied to measure peak <span class="hlt">strain</span> in rotating components; however, the sensitivity of the magnetic flux perturbation magnitude to the distance between the <span class="hlt">strain</span> sensing element and the electromagnet may require making an independent proximity measurement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840004375','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840004375"><span>Inflatable device for installing <span class="hlt">strain</span> gage bridges</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cook, C. E.; Smith, G. E.; Monaghan, R. C. (Inventor)</p> <p>1983-01-01</p> <p>Methods and devices for installing in a tubular shaft multiple <span class="hlt">strain</span> gages are disclosed with focus on a method and a device for pneumatically forcing <span class="hlt">strain</span> gages into seated engagement with the internal surfaces of a tubular shaft in an installation of multiple <span class="hlt">strain</span> gages in a tubular shaft. The <span class="hlt">strain</span> gages or other electron devices are seated in a template-like component which is wrapped about a pneumatically expansible body. The component is inserted into a shaft and the body is pneumatically expanded after a suitable adhesive was applied to the surfaces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9061E..31R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9061E..31R"><span>Distributed <span class="hlt">strain</span> monitoring for bridges: temperature effects</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Regier, Ryan; Hoult, Neil A.</p> <p>2014-03-01</p> <p>To better manage infrastructure assets as they reach the end of their service lives, quantitative data is required to better assess structural behavior and allow for more informed decision making. Distributed fiber optic <span class="hlt">strain</span> sensors are one sensing technology that could provide comprehensive data for use in structural assessments as these systems potentially allow for <span class="hlt">strain</span> to be measured with the same accuracy and gage lengths as conventional <span class="hlt">strain</span> sensors. However, as with many sensor technologies, temperature can play an important role in terms of both the structure's and sensor's performance. To investigate this issue a fiber optic distributed <span class="hlt">strain</span> sensor system was installed on a section of a two span reinforced concrete bridge on the TransCanada Highway. <span class="hlt">Strain</span> data was acquired several times a day as well as over the course of several months to explore the effects of changing temperature on the data. The results show that the <span class="hlt">strain</span> measurements are affected by the bridge behavior as a whole. The <span class="hlt">strain</span> measurements due to temperature are compared to <span class="hlt">strain</span> measurements that were taken during a load test on the bridge. The results show that even a small change in temperature can produce crack width and <span class="hlt">strain</span> changes similar to those due to a fully loaded transport truck. Future directions for research in this area are outlined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/2631512','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/2631512"><span>Differentiation of Listeria and Streptococcus <span class="hlt">strains</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Herendi, A; Ralovich, B</p> <p>1989-01-01</p> <p>Colonial morphology of non-beta haemolytic Listeria <span class="hlt">strains</span> is frequently similar to that of non-haemolytic streptococci. Biochemical characteristics, motility, haemolysis on ox blood agar, growth on Clauberg, selective streptococcus (Si) and Mitis-Salivarius agar medium, CAMP test, serological behaviour of 16 Listeria <span class="hlt">strains</span> were studied and the results were compared with the properties of Streptococcus <span class="hlt">strains</span>. Microscopic morphology, motility and catalase activity are useful for distinguishing these <span class="hlt">strains</span>. To avoid a false diagnosis, latex-agglutination should be supplemented with the above tests.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160000697','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160000697"><span>Acceleration and Velocity Sensing from Measured <span class="hlt">Strain</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pak, Chan-Gi; Truax, Roger</p> <p>2016-01-01</p> <p>A simple approach for computing acceleration and velocity of a structure from the <span class="hlt">strain</span> is proposed in this study. First, deflection and slope of the structure are computed from the <span class="hlt">strain</span> using a two-step theory. Frequencies of the structure are computed from the time histories of <span class="hlt">strain</span> using a parameter estimation technique together with an Autoregressive Moving Average model. From deflection, slope, and frequencies of the structure, acceleration and velocity of the structure can be obtained using the proposed approach. shape sensing, fiber optic <span class="hlt">strain</span> sensor, system equivalent reduction and expansion process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/7270427','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/7270427"><span>Effective heat <span class="hlt">strain</span> index using pocket computer.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kamon, E; Ryan, C</p> <p>1981-08-01</p> <p>An effective heat <span class="hlt">strain</span> index (EHSI) using a hand calculator with memory is suggested for on-site evaluation of prevailing hot ambient conditions. The inputs to the programmed calculator include dry-bulb, wet-bulb and globe temperatures, and estimates of metabolism and air movements. The index is based on a program for calculation of the total heat balance and on the efficiency of sweating. The display of information on the ambient conditions EHSI display is one of following: no <span class="hlt">strain</span>; low <span class="hlt">strain</span>; high <span class="hlt">strain</span>; or time limits of exposure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/867015','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/867015"><span>Optical fiber sensor technique for <span class="hlt">strain</span> measurement</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Butler, Michael A.; Ginley, David S.</p> <p>1989-01-01</p> <p>Laser light from a common source is split and conveyed through two similar optical fibers and emitted at their respective ends to form an interference pattern, one of the optical fibers having a portion thereof subjected to a <span class="hlt">strain</span>. Changes in the <span class="hlt">strain</span> cause changes in the optical path length of the <span class="hlt">strain</span> fiber, and generate corresponding changes in the interference pattern. The interference pattern is received and transduced into signals representative of fringe shifts corresponding to changes in the <span class="hlt">strain</span> experienced by the <span class="hlt">strained</span> one of the optical fibers. These signals are then processed to evaluate <span class="hlt">strain</span> as a function of time, typical examples of the application of the apparatus including electrodeposition of a metallic film on a conductive surface provided on the outside of the optical fiber being <span class="hlt">strained</span>, so that <span class="hlt">strains</span> generated in the optical fiber during the course of the electrodeposition are measurable as a function of time. In one aspect of the invention, signals relating to the fringe shift are stored for subsequent processing and analysis, whereas in another aspect of the invention the signals are processed for real-time display of the <span class="hlt">strain</span> changes under study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70187494','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70187494"><span>Using <span class="hlt">strain</span> rates to forecast seismic hazards</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Evans, Eileen</p> <p>2017-01-01</p> <p>One essential component in forecasting seismic hazards is observing the gradual accumulation of tectonic <span class="hlt">strain</span> accumulation along faults before this <span class="hlt">strain</span> is suddenly released as earthquakes. Typically, seismic hazard models are based on geologic estimates of slip rates along faults and historical records of seismic activity, neither of which records actively accumulating <span class="hlt">strain</span>. But this <span class="hlt">strain</span> can be estimated by geodesy: the precise measurement of tiny position changes of Earth’s surface, obtained from GPS, interferometric synthetic aperture radar (InSAR), or a variety of other instruments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2705517','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2705517"><span>Lattice <span class="hlt">Strain</span> Due to an Atomic Vacancy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Li, Shidong; Sellers, Michael S.; Basaran, Cemal; Schultz, Andrew J.; Kofke, David A.</p> <p>2009-01-01</p> <p>Volumetric <span class="hlt">strain</span> can be divided into two parts: <span class="hlt">strain</span> due to bond distance change and <span class="hlt">strain</span> due to vacancy sources and sinks. In this paper, efforts are focused on studying the atomic lattice <span class="hlt">strain</span> due to a vacancy in an FCC metal lattice with molecular dynamics simulation (MDS). The result has been compared with that from a continuum mechanics method. It is shown that using a continuum mechanics approach yields constitutive results similar to the ones obtained based purely on molecular dynamics considerations. PMID:19582230</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20976649','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20976649"><span><span class="hlt">Strain</span> accommodation in inelastic deformation of glasses</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Murali, P.; Ramamurty, U.; Shenoy, Vijay B.</p> <p>2007-01-01</p> <p>Motivated by recent experiments on metallic glasses, we examine the micromechanisms of <span class="hlt">strain</span> accommodation including crystallization and void formation during inelastic deformation of glasses by employing molecular statics simulations. Our atomistic simulations with Lennard-Jones-like potentials suggests that a softer short range interaction between atoms favors crystallization. Compressive hydrostatic <span class="hlt">strain</span> in the presence of a shear <span class="hlt">strain</span> promotes crystallization whereas a tensile hydrostatic <span class="hlt">strain</span> is found to induce voids. The deformation subsequent to the onset of crystallization includes partial reamorphization and recrystallization, suggesting important atomistic mechanisms of plastic dissipation in glasses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890000370&hterms=history+Base+data&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dhistory%2BBase%2Bdata','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890000370&hterms=history+Base+data&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dhistory%2BBase%2Bdata"><span>Predictions Of Fatigue Damage From <span class="hlt">Strain</span> Histories</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sire, Robert A.; Besuner, Philip M.; Toomey, Tim</p> <p>1989-01-01</p> <p>Semiempirical mathematical model of fatigue damage in stressed objects uses experimental histories of <span class="hlt">strains</span> in those objects to predict fatigue lives. Accounts for initiation and propagation of fatigue cracks on cycle-by-cycle basis. Measured <span class="hlt">strain</span> history first digitized, then converted to history of turning-point <span class="hlt">strains</span> for purposes of analysis. Data between turning points not used. When model calibrated against proper test data for each type of object characterized, its predictions of fatigue lives superior to statistical models as one based on root-mean-square <span class="hlt">strain</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/9749560','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/9749560"><span><span class="hlt">Strain</span> amplification in the bone mechanosensory system.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cowin, S C; Weinbaum, S</p> <p>1998-09-01</p> <p>This article discusses the potential mechanisms by which the <span class="hlt">strain</span> induced at the membrane of an osteocyte may be amplified from the <span class="hlt">strain</span> experienced by the whole bone due to mechanical loading. These mechanisms address the question of how these mechanical load-induced small <span class="hlt">strains</span> of (typically) about 0.1% (but up to 0.5%) applied to a whole bone are amplified to <span class="hlt">strains</span> of 1% or larger at the membrane of the osteocyte buried in its lacuna in the bone matrix. The answer to this question is an important link in the mechanosensory system in bone and in relating in vitro cell studies to in vivo cellular response.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2951977','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2951977"><span>Prion <span class="hlt">strain</span> interactions are highly selective</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Nilsson, K. Peter R.; Joshi-Barr, Shivanjali; Winson, Olivia; Sigurdson, Christina J.</p> <p>2010-01-01</p> <p>Various misfolded and aggregated neuronal proteins commonly co-exist in neurodegenerative disease, but whether the proteins co-aggregate and alter the disease pathogenesis is unclear. Here we used mixtures of distinct prion <span class="hlt">strains</span>, which are believed to differ in conformation, to test the hypothesis that two different aggregates interact and change the disease in vivo. We tracked two prion <span class="hlt">strains</span> in mice histopathologically and biochemically, as well as by spectral analysis of plaque-bound polythiophene acetic acid (PTAA), a conformation-sensitive fluorescent amyloid ligand. We found that prion <span class="hlt">strains</span> interacted in a highly selective and <span class="hlt">strain</span>-specific manner, with either (i) no interaction, (ii) hybrid plaque formation, or (iii) blockage of one <span class="hlt">strain</span> by a second (interference). The hybrid plaques were maintained upon further passage in vivo and each <span class="hlt">strain</span> seemed to maintain its original conformational properties, suggesting that one <span class="hlt">strain</span> served only as a scaffold for aggregation of the second <span class="hlt">strain</span>. These findings not only further our understanding of prion <span class="hlt">strain</span> interactions, but also directly demonstrate interactions that may occur in other protein aggregate mixtures. PMID:20826672</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25641620','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25641620"><span>Material approaches to stretchable <span class="hlt">strain</span> sensors.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Park, Jaeyoon; You, Insang; Shin, Sangbaie; Jeong, Unyong</p> <p>2015-04-27</p> <p>With the recent progress made in wearable electronics, devices now require high flexibility and stretchability up to large <span class="hlt">strain</span> levels (typically larger than 30 % <span class="hlt">strain</span>). Wearable <span class="hlt">strain</span> sensors or deformable <span class="hlt">strain</span> sensors have been gaining increasing research interest because of the rapid development of electronic skins and robotics and because of their biomedical applications. Conventional brittle <span class="hlt">strain</span> sensors made of metals and piezoresistors are not applicable for such stretchable sensors. This Review summarizes recent advances in stretchable sensors and focuses on material aspects for high stretchability and sensitivity. It begins with a brief introduction to the Wheatstone bridge circuit of conventional resistive <span class="hlt">strain</span> sensors. Then, studies on the manipulation of materials are reviewed, including waved structural approaches for making metals and semiconductors stretchable, the use of liquid metals, and conductive filler/elastomer composites by using percolation among the fillers. For capacitive <span class="hlt">strain</span> sensors, the constant conductivity of the electrode is a key factor in obtaining reliable sensors. Possible approaches to developing capacitive <span class="hlt">strain</span> sensors are presented. This Review concludes with a discussion on the major challenges and perspectives related to stretchable <span class="hlt">strain</span> sensors. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/7453585','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/7453585"><span>[Antigenic relationships between Debaryomyces <span class="hlt">strains</span> (author's transl)].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Aksoycan, N</p> <p>1980-01-01</p> <p>The results of the agglutinations between homologous and heterologous Debaryomyces <span class="hlt">strains</span> and their agglutinating sera are shown in table I. According to these findings, D. hansenii and D. marama are antigenically different from other Debaryomyces <span class="hlt">strains</span> in this genus. In a previous study Aksoycan et al. have shown a common antigenic factor between D. hansenii, D. marama <span class="hlt">strains</span> and Salmonella 0:7 antigen. This factor was not present in other six <span class="hlt">strains</span> of Debaryomyces. These results also show that D. tamarii does not have any antigenic relationship with the other seven species of Debaryomyces in this genus.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JNuM..451..264K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JNuM..451..264K"><span>True stress-<span class="hlt">strain</span> curves of cold worked stainless steel over a large range of <span class="hlt">strains</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kamaya, Masayuki; Kawakubo, Masahiro</p> <p>2014-08-01</p> <p>True stress-<span class="hlt">strain</span> curves for cold worked stainless steel were obtained over a range of <span class="hlt">strains</span> that included a large <span class="hlt">strain</span> exceeding the <span class="hlt">strain</span> for the tensile strength (post-necking <span class="hlt">strain</span>). A specified testing method was used to obtain the stress-<span class="hlt">strain</span> curves in air at room temperature. The testing method employed the digital image correlation (DIC) technique and iterative finite element analyses (FEA) and was referred to as IFD (Iteration FEA procedure based on DIC measurement) method. Although hourglass type specimens have been previously used for the IFD method, in this study, plate specimens with a parallel gage section were used to obtain accurate yield and tensile strengths together with the stress-<span class="hlt">strain</span> curves. The stress-<span class="hlt">strain</span> curves including the post-necking <span class="hlt">strain</span> were successfully obtained by the IFD method, and it was shown that the stress-<span class="hlt">strain</span> curves for different degrees of cold work collapsed onto a single curve when the offset <span class="hlt">strain</span> was considered. It was also shown that the Swift type constitutive equation gave good regression for the true stress-<span class="hlt">strain</span> curves including the post-necking <span class="hlt">strain</span> regardless of the degree of cold work, although the Ramberg-Osgood type constitutive equation showed poor fit. In the regression for the Swift type constitutive equation, the constant for power law could be assumed to be nS = 0.5.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10878089','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10878089"><span>Surveillance of rotavirus <span class="hlt">strains</span> in the United States: identification of unusual <span class="hlt">strains</span>. The National Rotavirus <span class="hlt">Strain</span> Surveillance System collaborating laboratories.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Griffin, D D; Kirkwood, C D; Parashar, U D; Woods, P A; Bresee, J S; Glass, R I; Gentsch, J R</p> <p>2000-07-01</p> <p>Rotavirus <span class="hlt">strains</span> from 964 fecal specimens collected from children at 11 U.S. hospital laboratories from November 1997 to March 1998 and from samples collected at 12 laboratories from November 1998 to March 1999 were typed for G and P proteins. Serotype G1 was the predominant serotype in 1997-1998 (88%), followed by G2 (6.2%), G9 (3.3%), and G3 (1.5%). This pattern was similar to that seen in 1998-1999: G1 (79%), G2 (15%), G9 (3.0%), G4 (1.6%), and G3 (0.3%). Novel P[9] <span class="hlt">strains</span> were identified in both seasons, and analysis of a 364-nucleotide fragment from gene segment 4 of one of the <span class="hlt">strains</span> demonstrated 97.3% nucleotide identity with the prototype P3[9],G3 <span class="hlt">strain</span>, AU1, isolated in Japan. This is the first report of a human AU1-like <span class="hlt">strain</span> in the United States. These results reinforce our initial findings that serotype G9 persists in the United States but has not become a predominant <span class="hlt">strain</span> and that the common serotypes G1 to G4 account for almost 90% of <span class="hlt">strains</span> in circulation. Other uncommon <span class="hlt">strains</span> exist in the United States but may have been overlooked before because of their low prevalence and the use of inadequate diagnostic tools.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950047316&hterms=Rebound&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DRebound','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950047316&hterms=Rebound&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DRebound"><span>A comparison of eastern North American seismic <span class="hlt">strain</span>-rates to glacial rebound <span class="hlt">strain</span>-rates</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>James, Thomas S.; Bent, Allison L.</p> <p>1994-01-01</p> <p>Glacial rebound <span class="hlt">strain</span>-rates computed using a simple Laurentide glacial loading model are of the order of 10(exp -9) per year within the region of glaciation and extending several hundred kilometers beyond. The horizontal <span class="hlt">strain</span>-rates receive approximately equal contributions from horizontal and vertical velocities, a consequence of the spherical geometry adopted for the Earth model. In the eastern United States and southeastern Canada the computed <span class="hlt">strain</span>-rates are 1-3 orders of magnitude greater than an estimate of the average seismic <span class="hlt">strain</span>-rate (Anderson, 1986) and approximately 1 order of magnitude greater than predicted erosional <span class="hlt">strain</span>-rates. The predicted glacial rebound <span class="hlt">strain</span>-rates are not, in general, oriented in such a way as to augment the observed state of deviatoric stress, possibly explaining why the seismic <span class="hlt">strain</span>-rates are much smaller than the glacial rebound <span class="hlt">strain</span>-rates. An exception to this may be seismically active regions in the St. Lawrence valley.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950047316&hterms=seismic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dseismic','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950047316&hterms=seismic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dseismic"><span>A comparison of eastern North American seismic <span class="hlt">strain</span>-rates to glacial rebound <span class="hlt">strain</span>-rates</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>James, Thomas S.; Bent, Allison L.</p> <p>1994-01-01</p> <p>Glacial rebound <span class="hlt">strain</span>-rates computed using a simple Laurentide glacial loading model are of the order of 10(exp -9) per year within the region of glaciation and extending several hundred kilometers beyond. The horizontal <span class="hlt">strain</span>-rates receive approximately equal contributions from horizontal and vertical velocities, a consequence of the spherical geometry adopted for the Earth model. In the eastern United States and southeastern Canada the computed <span class="hlt">strain</span>-rates are 1-3 orders of magnitude greater than an estimate of the average seismic <span class="hlt">strain</span>-rate (Anderson, 1986) and approximately 1 order of magnitude greater than predicted erosional <span class="hlt">strain</span>-rates. The predicted glacial rebound <span class="hlt">strain</span>-rates are not, in general, oriented in such a way as to augment the observed state of deviatoric stress, possibly explaining why the seismic <span class="hlt">strain</span>-rates are much smaller than the glacial rebound <span class="hlt">strain</span>-rates. An exception to this may be seismically active regions in the St. Lawrence valley.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016IJN....1560005S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016IJN....1560005S"><span>Simulation and Analysis of <span class="hlt">Strain</span> Sensitivity of CNT-Based <span class="hlt">Strain</span> Sensors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sapra, Gaurav; Vig, Renu; Sharma, Manu</p> <p>2016-10-01</p> <p>Carbon nanotubes (CNT) is turning out to be a replacement to all the existing traditional sensors due to their high gauge factor, multidirectional sensing capability, high flexibility, low mass density, high dynamic range and high sensitivity to <span class="hlt">strains</span> at nano and macro- scales. The <span class="hlt">strain</span> sensitivity of CNT-based <span class="hlt">strain</span> sensors depends on number of parameters; quality and quantity of CNT used, type of polymer used, deposition and dispersion technique adopted and also on environmental conditions. Due to all these parameters, the piezoresistive behavior of CNT is diversified and it needs to be explored. This paper theoretically analyses the <span class="hlt">strain</span> sensitivity of CNT-based <span class="hlt">strain</span> sensors. The <span class="hlt">strain</span> sensitivity response of CNT <span class="hlt">strain</span> sensor is a result of change in total resistance of CNT network with respect to applied <span class="hlt">strain</span>. The total resistance of CNT network consists of intrinsic resistance and inter-tube resistance. It has been found that the change in intrinsic resistance under <span class="hlt">strain</span> is due to the variation of bandgap of individual, which depends on the chirality of the tube and it varies exponentially with <span class="hlt">strain</span>. The inter-tube resistance of CNT network changes nonlinearly due to change in distance between neighboring CNTs with respect to applied <span class="hlt">strain</span>. As the distance d between CNTs increases due to applied <span class="hlt">strain</span>, tunneling resistance Rtunnel increases nonlinearly in exponential manner. When the concentration of CNTs in composite is close to percolation threshold, then the change of inter-tube resistances is more dominant than intrinsic resistance. At percolation threshold, the total resistance of CNT networks changes nonlinearly and this effect of nonlinearity is due to tunneling effect. The <span class="hlt">strain</span> sensitivity of CNT-based <span class="hlt">strain</span> sensors also varies nonlinearly with the change in temperature. For the change of temperature from -20∘C to 50∘C, there is more than 100% change in <span class="hlt">strain</span> sensitivity of CNT/polymer composite <span class="hlt">strain</span> sensor. This change is</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/495681','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/495681"><span>Bicrystals with <span class="hlt">strain</span> gradient effects</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Shu, J.Y.</p> <p>1997-01-09</p> <p>Boundary between two perfectly bonded single crystals plays an important role in determining the deformation of the bicrystals. This work addresses the role of the grain boundary by considering the elevated hardening of a slip system due to a slip gradient. The slip gradients are associated with geometrically necessary dislocations and their effects become pronounced when a representative length scale of the deformation field is comparable to the dominant microstructural length scale of a material. A new rate-dependent crystal plasticity theory is presented and has been implemented within the finite element method framework. A planar bicrystal under uniform in-plane loading is studied using the new crystal theory. The <span class="hlt">strain</span> is found to be continuous but nonuniform within a boundary layer around the interface. The lattice rotation is also nonuniform within the boundary layer. The width of the layer is determined by the misorientation of the grains, the hardening of slip systems, and most importantly by the characteristic material length scales. The overall yield strength of the bicrystal is also obtained. A significant grain-size dependence of the yield strength, the Hall- Petch effect is predicted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AIPC.1426..167J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AIPC.1426..167J"><span>High <span class="hlt">strain</span> rate behavior of polyurea compositions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Joshi, Vasant S.; Milby, Christopher</p> <p>2012-03-01</p> <p>High-<span class="hlt">strain</span>-rate response of three polyurea compositions with varying molecular weights has been investigated using a Split Hopkinson Pressure Bar arrangement equipped with aluminum bars. Three polyurea compositions were synthesized from polyamines (Versalink, Air Products) with a multi-functional isocyanate (Isonate 143L, Dow Chemical). Amines with molecular weights of 1000, 650, and a blend of 250/1000 have been used in the current investigation. These materials have been tested to <span class="hlt">strain</span> rates of over 6000/s. High <span class="hlt">strain</span> rate results from these tests have shown varying trends as a function of increasing <span class="hlt">strain</span>. While higher molecular weight composition show lower yield, they do not show dominant hardening behavior at lower <span class="hlt">strain</span>. On the other hand, the blend of 250/1000 show higher load bearing capability but lower <span class="hlt">strain</span> hardening effects than the 600 and 1000 molecular weight amine based materials. Results indicate that the initial increase in the modulus of the blend of 250/1000 may lead to the loss of <span class="hlt">strain</span> hardening characteristics as the material is compressed to 50% <span class="hlt">strain</span>, compared to 1000 molecular weight amine based material.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=243376','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=243376"><span>Surfactin production by <span class="hlt">strains</span> of Bacillus mojavensis</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>Bacillus mojavensis, RRC101 is an endophytic bacterium patented for control of fungal diseases in maize and other plants. DNA fingerprint analysis of the rep-PCR fragments of 35 B. mojavensis and 4 B. subtilis <span class="hlt">strains</span> using the Diversilab genotyping system revealed genotypic distinctive <span class="hlt">strains</span> alon...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22412602','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22412602"><span><span class="hlt">Strain</span> engineering in graphene by laser irradiation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Papasimakis, N.; Mailis, S.; Huang, C. C.; Al-Saab, F.; Hewak, D. W.; Luo, Z.; Shen, Z. X.</p> <p>2015-02-09</p> <p>We demonstrate that the Raman spectrum of graphene on lithium niobate can be controlled locally by continuous exposure to laser irradiation. We interpret our results in terms of changes to doping and mechanical <span class="hlt">strain</span> and show that our observations are consistent with light-induced gradual <span class="hlt">strain</span> relaxation in the graphene layer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED208517.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED208517.pdf"><span>Fiscal <span class="hlt">Strain</span> in an Era of Retrenchment.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Hentschke, Guilbert; Yagielski, John</p> <p></p> <p>Preliminary results of a three-year study of fifteen school districts indicate that fiscal <span class="hlt">strain</span> results from both "intended" and "unintended" factors. The authors construct a model of fiscal <span class="hlt">strain</span> that combines budget constraints with school district decision-makers' preference functions and indifference curves. Using this model and 1976 and…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28729269','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28729269"><span>Multiple Genome Sequences of Lactobacillus plantarum <span class="hlt">Strains</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kafka, Thomas A; Geissler, Andreas J; Vogel, Rudi F</p> <p>2017-07-20</p> <p>We report here the genome sequences of four Lactobacillus plantarum <span class="hlt">strains</span> which vary in surface hydrophobicity. Bioinformatic analysis, using additional genomes of Lactobacillus plantarum <span class="hlt">strains</span>, revealed a possible correlation between the cell wall teichoic acid-type and cell surface hydrophobicity and provide the basis for consecutive analyses. Copyright © 2017 Kafka et al.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5522936','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5522936"><span>Multiple Genome Sequences of Lactobacillus plantarum <span class="hlt">Strains</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kafka, Thomas A.; Geissler, Andreas J.</p> <p>2017-01-01</p> <p>ABSTRACT We report here the genome sequences of four Lactobacillus plantarum <span class="hlt">strains</span> which vary in surface hydrophobicity. Bioinformatic analysis, using additional genomes of Lactobacillus plantarum <span class="hlt">strains</span>, revealed a possible correlation between the cell wall teichoic acid-type and cell surface hydrophobicity and provide the basis for consecutive analyses. PMID:28729269</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993STIN...9426568W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993STIN...9426568W"><span>Attachment techniques for high temperature <span class="hlt">strain</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wnuk, Steve P., Jr.</p> <p>1993-01-01</p> <p>Attachment methods for making resistive <span class="hlt">strain</span> measurements to 2500 F were studied. A survey of available <span class="hlt">strain</span> gages and attachment techniques was made, and the results are compiled for metal and carbon composite test materials. A theoretical analysis of <span class="hlt">strain</span> transfer into a bonded <span class="hlt">strain</span> gage was made, and the important physical parameters of the <span class="hlt">strain</span> transfer medium, the ceramic matrix, were identified. A pull tester to measure pull-out tests on commonly used <span class="hlt">strain</span> gage cements indicated that all cements tested displayed adequate strength for good <span class="hlt">strain</span> transfer. Rokide flame sprayed coatings produced significantly stronger bonds than ceramic cements. An in-depth study of the flame spray process produced simplified installation procedures which also resulted in greater reliability and durability. Application procedures incorporating improvements made during this program are appended to the report. <span class="hlt">Strain</span> gages installed on carbon composites, Rene' 41, 316 stainless steel, and TZM using attachment techniques developed during this program were successfully tested to 2500 F. Photographs of installation techniques, test procedures, and graphs of the test data are included in this report.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=medicaid&pg=5&id=EJ1001107','ERIC'); return false;" href="https://eric.ed.gov/?q=medicaid&pg=5&id=EJ1001107"><span>Medically Complex Home Care and Caregiver <span class="hlt">Strain</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Moorman, Sara M.; Macdonald, Cameron</p> <p>2013-01-01</p> <p>Purpose of the study: To examine (a) whether the content of caregiving tasks (i.e., nursing vs. personal care) contributes to variation in caregivers' <span class="hlt">strain</span> and (b) whether the level of complexity of nursing tasks contributes to variation in <span class="hlt">strain</span> among caregivers providing help with such tasks. Design and methods: The data came from the Cash…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007ApPhL..90d1114T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007ApPhL..90d1114T"><span>Tomographic reconstruction of picosecond acoustic <span class="hlt">strain</span> propagation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tomoda, Motonobu; Matsuda, Osamu; Wright, Oliver B.; Li Voti, Roberto</p> <p>2007-01-01</p> <p>By means of an ultrafast optical technique, picosecond acoustic <span class="hlt">strain</span> pulses in a transparent medium are tomographically visualized. The authors reconstruct <span class="hlt">strain</span> pulses in Au-coated glass from time-domain reflectivity changes as a function of the optical angle of incidence, with ˜1ps temporal and ˜100nm spatial resolutions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=nursing+AND+care&id=EJ1001107','ERIC'); return false;" href="http://eric.ed.gov/?q=nursing+AND+care&id=EJ1001107"><span>Medically Complex Home Care and Caregiver <span class="hlt">Strain</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Moorman, Sara M.; Macdonald, Cameron</p> <p>2013-01-01</p> <p>Purpose of the study: To examine (a) whether the content of caregiving tasks (i.e., nursing vs. personal care) contributes to variation in caregivers' <span class="hlt">strain</span> and (b) whether the level of complexity of nursing tasks contributes to variation in <span class="hlt">strain</span> among caregivers providing help with such tasks. Design and methods: The data came from the Cash…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19870006976','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19870006976"><span>Silicon stress/<span class="hlt">strain</span> activities at JPL</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chen, C. P.</p> <p>1986-01-01</p> <p>In-house Jet Propulsion Laboratory (JPL) work is described for silicon stress/<span class="hlt">strain</span>, including the study of fracture mechanics, and on the high-temperature test program in which the low-<span class="hlt">strain</span> response of silicon sheet materials above 1000 C is being measured and high temperature material property data are being determined.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19860019923','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19860019923"><span>Analysis of silicon stress/<span class="hlt">strain</span> relationships</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dillon, O.</p> <p>1985-01-01</p> <p>In the study of stress-<span class="hlt">strain</span> relationships in silicon ribbon, numerous solutions were calculated for stresses, <span class="hlt">strain</span> rates, and dislocation densities through the use of the Sumino model. It was concluded that many cases of failure of computer solutions to converge are analytical manifestations of shear bands (Luder's band) observed in experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19810000068&hterms=phase+locked+loop&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dphase%2Blocked%2Bloop','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19810000068&hterms=phase+locked+loop&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dphase%2Blocked%2Bloop"><span>Pulsed Phase-Locked-Loop <span class="hlt">Strain</span> Monitor</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Heyman, J. S.; Stone, F. D.</p> <p>1982-01-01</p> <p>P2sup.L2sup. <span class="hlt">strain</span> monitor measures <span class="hlt">strain</span> by monitoring change in phase of acoustic signal that passes through stressed sample. Phase sample causes shift in frequency of VCO. As with other monitors of this type, instrument is only accurate in elastic range of material. Monitor is expected to have broad application in materials testing, structural design, fabrication and assembly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/8719177','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/8719177"><span>A natural vaccine candidate <span class="hlt">strain</span> against cholera.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Y Q; Qi, G M; Wang, S X; Yu, Y M; Duan, G C; Zhang, L J; Gao, S Y</p> <p>1995-12-01</p> <p>E1 Tor Vibrio cholerae (EVC) <span class="hlt">strains</span> may be classified into two kinds-epidemigenic (EEVC) <span class="hlt">strains</span> and non-epidemigenic (NEEVC) <span class="hlt">strains</span>-based on a phage-biotyping system. A large number of EEVC <span class="hlt">strains</span> have been screened for toxigenic and putative colonization attributes. One such naturally occurring <span class="hlt">strains</span> (designated IEM101) has been found which is devoid of genes encoding cholera toxin (CT), accessory cholera enterotoxin (ACE), zonula occludens toxin (ZOT), but possesses RS1 sequences and toxin-coregulated pilus A gene (icpA) although icpA is poorly expressed. It expresses type B pili but does not possess type C pili. It is an E1 Tor Ogawa <span class="hlt">strain</span> and does not cause fluid accumulation in rabbit ilcal loop tests. Active immunization of rabbits with <span class="hlt">strain</span> IEM101 elicited good protection against challenge with virulent <span class="hlt">strains</span> of V. cholerae O1. Oral administration caused no side effects in 15 human volunteers, colonized the gut for four to ten days and elicited good immune responses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090011203','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090011203"><span>Nanocomposite <span class="hlt">Strain</span> Gauges Having Small TCRs</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gregory, Otto; Chen, Ximing</p> <p>2009-01-01</p> <p>Ceramic <span class="hlt">strain</span> gauges in which the <span class="hlt">strain</span>-sensitive electrically conductive strips made from nanocomposites of noble metal and indium tin oxide (ITO) are being developed for use in gas turbine engines and other power-generation systems in which gas temperatures can exceed 1,500 F (about 816 C). In general, <span class="hlt">strain</span> gauges exhibit spurious thermally induced components of response denoted apparent <span class="hlt">strain</span>. When temperature varies, a <span class="hlt">strain</span>-gauge material that has a nonzero temperature coefficient of resistance (TCR) exhibits an undesired change in electrical resistance that can be mistaken for the change in resistance caused by a change in <span class="hlt">strain</span>. It would be desirable to formulate straingauge materials having TCRs as small as possible so as to minimize apparent <span class="hlt">strain</span>. Most metals exhibit positive TCRs, while most semiconductors, including ITO, exhibit negative TCRs. The present development is based on the idea of using the negative TCR of ITO to counter the positive TCRs of noble metals and of obtaining the benefit of the ability of both ITO and noble metals to endure high temperatures. The noble metal used in this development thus far has been platinum. Combinatorial libraries of many ceramic <span class="hlt">strain</span> gauges containing nanocomposites of various proportions of ITO and platinum were fabricated by reactive co-sputtering from ITO and platinum targets onto alumina- and zirconia-based substrates mounted at various positions between the targets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19700000207','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19700000207"><span>Inorganic bonding of semiconductor <span class="hlt">strain</span> gages</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Woodruff, N. L.</p> <p>1970-01-01</p> <p>Inorganic bonding materials minimize outgassing and improve electrical and mechanical properties of semiconductor <span class="hlt">strain</span>-gage transducers in high-vacuum and high-temperature operations. The two basic methods described are ceramic-glass-bonding and metallic bond formation between the <span class="hlt">strain</span> gage and the substrate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=punishment+AND+child&pg=7&id=EJ808655','ERIC'); return false;" href="http://eric.ed.gov/?q=punishment+AND+child&pg=7&id=EJ808655"><span>General <span class="hlt">Strain</span> Theory and Delinquency: Focusing on the Influences of Key <span class="hlt">Strain</span> Characteristics on Delinquency</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Moon, Byongook; Blurton, David; McCluskey, John D.</p> <p>2008-01-01</p> <p>The study examines the effects of recent, older, and chronic <span class="hlt">strains</span> and of perceived injustice of <span class="hlt">strain</span> on delinquency, sampling 777 Korean youth. Seven key <span class="hlt">strains</span> most likely leading to delinquency, some of which were often overlooked in previous research, were included, and these are family conflict, parental punishment, teachers' punishment,…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23144418','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23144418"><span>Complete genome sequence of Brucella canis <span class="hlt">strain</span> 118, a <span class="hlt">strain</span> isolated from canine.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gao, Guangjun; Li, Jing; Li, Tiefeng; Zhang, Zhengfang; Wang, Liping; Yuan, Xitong; Wang, Yufei; Xu, Jie; Ke, Yuehua; Huang, Liuyu; Wang, Dali; Chen, Zeliang; Xu, Xingran</p> <p>2012-12-01</p> <p>Brucella canis infects several species of animals, and canine is the preferred host. Genome sequences of <span class="hlt">strains</span> from different hosts are valuable for comparative analysis of host adaptation and microevolution. Here, we report the genome sequence of Brucella canis <span class="hlt">strain</span> 118, a <span class="hlt">strain</span> isolated from canine.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/82645','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/82645"><span>On certain aspects of <span class="hlt">strain</span> rate sensitivity of sheet metals</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Shi, M.F.; Meuleman, D.J.</p> <p>1995-06-01</p> <p>The formability of a material depends upon the <span class="hlt">strain</span> hardening and <span class="hlt">strain</span> rate hardening of the material. In this study, constitutive parameters using the power law constitutive equation are determined for six different strength steels and two aluminum alloys over different <span class="hlt">strain</span> ranges, including approximations of the postuniform elongation range. Constitutive parameters are found to be different at different <span class="hlt">strain</span> ranges. The <span class="hlt">strain</span> hardening of steels increases with <span class="hlt">strain</span> at low <span class="hlt">strain</span> levels (less than 5%) and decreases at high <span class="hlt">strain</span> levels (greater than 10%). <span class="hlt">Strain</span> rate hardening decreases with <span class="hlt">strain</span> for all steels and aluminum alloys. Uniform elongation depends only on <span class="hlt">strain</span> hardening, and postuniform elongation depends only on <span class="hlt">strain</span> rate hardening. However, the total elongation depends on both <span class="hlt">strain</span> hardening and <span class="hlt">strain</span> rate hardening.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26649476','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26649476"><span>Mechanical <span class="hlt">strain</span> effects on black phosphorus nanoresonators.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Cui-Xia; Zhang, Chao; Jiang, Jin-Wu; Park, Harold S; Rabczuk, Timon</p> <p>2016-01-14</p> <p>We perform classical molecular dynamics simulations to investigate the effects of mechanical <span class="hlt">strain</span> on single-layer black phosphorus nanoresonators at different temperatures. We find that the resonant frequency is highly anisotropic in black phosphorus due to its intrinsic puckered configuration, and that the quality factor in the armchair direction is higher than in the zigzag direction at room temperature. The quality factors are also found to be intrinsically larger than those in graphene and MoS2 nanoresonators. The quality factors can be increased by more than a factor of two by applying tensile <span class="hlt">strain</span>, with uniaxial <span class="hlt">strain</span> in the armchair direction being the most effective. However, there is an upper bound for the quality factor increase due to nonlinear effects at large <span class="hlt">strains</span>, after which the quality factor decreases. The tension induced nonlinear effect is stronger along the zigzag direction, resulting in a smaller maximum <span class="hlt">strain</span> for quality factor enhancement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ApPhL.104g3108U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ApPhL.104g3108U"><span>Nanoscale <span class="hlt">strain</span> mapping in battery nanostructures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ulvestad, A.; Cho, H. M.; Harder, R.; Kim, J. W.; Dietze, S. H.; Fohtung, E.; Meng, Y. S.; Shpyrko, O. G.</p> <p>2014-02-01</p> <p>Coherent x-ray diffraction imaging is used to map the local three dimensional <span class="hlt">strain</span> inhomogeneity and electron density distribution of two individual LiNi0.5Mn1.5O4-δ cathode nanoparticles in both ex-situ and in-situ environments. Our reconstructed images revealed a maximum <span class="hlt">strain</span> of 0.4%. We observed different variations in <span class="hlt">strain</span> inhomogeneity due to multiple competing effects. The compressive/tensile component of the <span class="hlt">strain</span> is connected to the local lithium content and, on the surface, interpreted in terms of a local Jahn-Teller distortion of Mn3+. Finally, the measured <span class="hlt">strain</span> distributions are discussed in terms of their impact on competing theoretical models of the lithiation process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24799688','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24799688"><span>Extraordinary <span class="hlt">strain</span> hardening by gradient structure.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wu, XiaoLei; Jiang, Ping; Chen, Liu; Yuan, Fuping; Zhu, Yuntian T</p> <p>2014-05-20</p> <p>Gradient structures have evolved over millions of years through natural selection and optimization in many biological systems such as bones and plant stems, where the structures change gradually from the surface to interior. The advantage of gradient structures is their maximization of physical and mechanical performance while minimizing material cost. Here we report that the gradient structure in engineering materials such as metals renders a unique extra <span class="hlt">strain</span> hardening, which leads to high ductility. The grain-size gradient under uniaxial tension induces a macroscopic <span class="hlt">strain</span> gradient and converts the applied uniaxial stress to multiaxial stresses due to the evolution of incompatible deformation along the gradient depth. Thereby the accumulation and interaction of dislocations are promoted, resulting in an extra <span class="hlt">strain</span> hardening and an obvious <span class="hlt">strain</span> hardening rate up-turn. Such extraordinary <span class="hlt">strain</span> hardening, which is inherent to gradient structures and does not exist in homogeneous materials, provides a hitherto unknown strategy to develop strong and ductile materials by architecting heterogeneous nanostructures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6565562','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6565562"><span><span class="hlt">Strain</span> rate effects in stress corrosion cracking</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Parkins, R.N. . Dept. of Metallurgy and Engineering Materials)</p> <p>1990-03-01</p> <p>Slow <span class="hlt">strain</span> rate testing (SSRT) was initially developed as a rapid, ad hoc laboratory method for assessing the propensity for metals an environments to promote stress corrosion cracking. It is now clear, however, that there are good theoretical reasons why <span class="hlt">strain</span> rate, as opposed to stress per se, will often be the controlling parameter in determining whether or not cracks are nucleated and, if so, are propagated. The synergistic effects of the time dependence of corrosion-related reactions and microplastic <span class="hlt">strain</span> provide the basis for mechanistic understanding of stress corrosion cracking in high-pressure pipelines and other structures. However, while this may be readily comprehended in the context of laboratory slow <span class="hlt">strain</span> tests, its extension to service situations may be less apparent. Laboratory work involving realistic stressing conditions, including low-frequency cyclic loading, shows that <span class="hlt">strain</span> or creep rates give good correlation with thresholds for cracking and with crack growth kinetics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040090018&hterms=Mechanosensitive+channels&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DMechanosensitive%2Bchannels','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040090018&hterms=Mechanosensitive+channels&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DMechanosensitive%2Bchannels"><span>Transduction of mechanical <span class="hlt">strain</span> in bone</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Duncan, R. L.</p> <p>1995-01-01</p> <p>One physiologic consequence of extended periods of weightlessness is the rapid loss of bone mass associated with skeletal unloading. Conversely, mechanical loading has been shown to increase bone formation and stimulate osteoblastic function. The mechanisms underlying mechanotransduction, or how the osteoblast senses and converts biophysical stimuli into cellular responses has yet to be determined. For non-innervated mechanosensitive cells like the osteoblast, mechanotransduction can be divided into four distinct phases: 1) mechanocoupling, or the characteristics of the mechanical force applied to the osteoblast, 2) biochemical coupling, or the mechanism through which mechanical <span class="hlt">strain</span> is transduced into a cellular biochemical signal, 3) transmission of signal from sensor to effector cell and 4) the effector cell response. This review examines the characteristics of the mechanical <span class="hlt">strain</span> encountered by osteoblasts, possible biochemical coupling mechanisms, and how the osteoblast responds to mechanical <span class="hlt">strain</span>. Differences in osteoblastic responses to mechanical <span class="hlt">strain</span> are discussed in relation to the types of <span class="hlt">strain</span> encountered and the possible transduction pathways involved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=250420','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=250420"><span>Facultatively Parasitic <span class="hlt">Strain</span> of Bdellovibrio bacteriovorus1</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Diedrich, D. L.; Denny, C. F.; Hashimoto, T.; Conti, S. F.</p> <p>1970-01-01</p> <p>A <span class="hlt">strain</span> of Bdellovibrio bacteriovorus (designated <span class="hlt">strain</span> UKi2) was isolated which was capable of growing either saprophytically in host-free medium or endoparasitically in Escherichia coli B/r. It was quantitatively determined that each bdellovibrio could develop in solid medium to produce a colony, and 65% of the cells in a late exponential-phase culture were capable of inducing E. coli B/r spheroplasts. A photomicrographic sequence of single E. coli spheroplasts containing bdellovibrios demonstrated that parasitically derived B. bacteriovorus UKi2 could develop saprophytically after release from the host cells. <span class="hlt">Strain</span> UKi2 appears to be morphologically quite similar to previously described obligately parasitic bdellovibrios; biochemical data on this <span class="hlt">strain</span> suggests its close relationship to some of the previously described host-independent <span class="hlt">strains</span> of Bdellovibrio. Images PMID:4908792</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20392048','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20392048"><span><span class="hlt">Strain</span> stiffening in synthetic and biopolymer networks.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Erk, Kendra A; Henderson, Kevin J; Shull, Kenneth R</p> <p>2010-05-10</p> <p><span class="hlt">Strain</span>-stiffening behavior common to biopolymer networks is difficult to reproduce in synthetic networks. Physically associating synthetic polymer networks can be an exception to this rule and can demonstrate <span class="hlt">strain</span>-stiffening behavior at relatively low values of <span class="hlt">strain</span>. Here, the stiffening behavior of model elastic networks of physically associating triblock copolymers is characterized by shear rheometry. Experiments demonstrate a clear correlation between network structure and <span class="hlt">strain</span>-stiffening behavior. Stiffening is accurately captured by a constitutive model with a single fitting parameter related to the midblock length. The same model is also effective for describing the stiffening of actin, collagen, and other biopolymer networks. Our synthetic polymer networks could be useful model systems for biological materials due to (1) the observed similarity in <span class="hlt">strain</span>-stiffening behavior, which can be quantified and related to network structure, and (2) the tunable structure of the physically associating network, which can be manipulated to yield a desired response.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040090018&hterms=signal+transduction&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsignal%2Btransduction','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040090018&hterms=signal+transduction&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsignal%2Btransduction"><span>Transduction of mechanical <span class="hlt">strain</span> in bone</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Duncan, R. L.</p> <p>1995-01-01</p> <p>One physiologic consequence of extended periods of weightlessness is the rapid loss of bone mass associated with skeletal unloading. Conversely, mechanical loading has been shown to increase bone formation and stimulate osteoblastic function. The mechanisms underlying mechanotransduction, or how the osteoblast senses and converts biophysical stimuli into cellular responses has yet to be determined. For non-innervated mechanosensitive cells like the osteoblast, mechanotransduction can be divided into four distinct phases: 1) mechanocoupling, or the characteristics of the mechanical force applied to the osteoblast, 2) biochemical coupling, or the mechanism through which mechanical <span class="hlt">strain</span> is transduced into a cellular biochemical signal, 3) transmission of signal from sensor to effector cell and 4) the effector cell response. This review examines the characteristics of the mechanical <span class="hlt">strain</span> encountered by osteoblasts, possible biochemical coupling mechanisms, and how the osteoblast responds to mechanical <span class="hlt">strain</span>. Differences in osteoblastic responses to mechanical <span class="hlt">strain</span> are discussed in relation to the types of <span class="hlt">strain</span> encountered and the possible transduction pathways involved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AIPC.1857d0011H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1857d0011H"><span><span class="hlt">Strain</span> analyis in Banda Sea using grid <span class="hlt">strain</span> based on GPS observation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Herawati, Yola Asis; Meilano, Irwan; Sarsito, Dina Anggreni; Effendi, Jony</p> <p>2017-07-01</p> <p>Eastern Indonesia has very high deformation due to tectonic activity in triple junction area. Convergencing between plate in Eastern Indonesia trigger some microblocks. Tectonic block as one of deformation phenomenom due to the interaction of between plates can be understood by using <span class="hlt">strain</span> analysis. <span class="hlt">Strain</span> analysis shows the change of position, shape and dimension from an object. This research use 80 GPS from previous study by Koulali et al, (2015) and 7 continuous GPS in Bird's Head to calculate <span class="hlt">strain</span> rates in order to find relation between tectonic activity and <span class="hlt">strain</span> rates in Banda Sea, and to identify block boundary. The GPS data are calculated using GAMIT/GLOBK software to obtain time series in each station. <span class="hlt">Strain</span> rates are calculated using softwae package named grid <span class="hlt">strain</span> which calculate <span class="hlt">strain</span> based on interpolation using discretized geodetic measurement resulting <span class="hlt">strain</span> rates in grid system. The data distribution and algorithm in grid <span class="hlt">strain</span> influence the result of <span class="hlt">strain</span> rates from grid <span class="hlt">strain</span>. The result from <span class="hlt">strain</span> calculation is in ranges -16,421×10-8 to -0,194×10-8 for shortening parameter and 1,653×10-8 to 18,92×10-8 for extension parameter. From <span class="hlt">strain</span> analysis known that <span class="hlt">strain</span> rates can identify tectonic activity but not accurately for block boundary. Banda Block, Timor Block, and Bird's Head Block has different <span class="hlt">strain</span> pattern especially in their boundary. Timor and eastern part of Banda Block dominated by shortening according to the back arc located in there, meanwhile western part of Banda Block and mostly of Bird's Head dominated by very low shortening according to collision between Eurasia and Australia Plates. For further analysis need some additional data such as density of GPS sites, sesimicity, and gravity data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1810513Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1810513Q"><span>Micro-scale <span class="hlt">strain</span> mapping technique: a tool to quantify <span class="hlt">strain</span> partitioning during creep deformation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Quintanilla-Terminel, Alejandra; Zimmerman, Mark; Evans, Brian; Kohlstedt, David</p> <p>2016-04-01</p> <p>Several deformation mechanisms interact to accommodate plastic deformation. Quantifying the contribution of each to the total <span class="hlt">strain</span> is necessary for establishing a better link between observed microstructures and mechanical data, as well as to allow more confident extrapolation from laboratory to natural conditions. In this contribution, we present the experimental and computational technique involved in micro-scale <span class="hlt">strain</span> mapping (MSSM). The MSSM technique relies on analyzing the relative displacement of initially regularly spaced markers after deformation. We present several microfabrication techniques that permit us to pattern various rocks with micrometric and nanometric metal markers, as well as the challenges faced in working at high temperatures and pressures. A Hough transform algorithm was used to detect the markers and automate as much as possible the <span class="hlt">strain</span> analysis. The von Mises <span class="hlt">strain</span> is calculated for a set of n-points and their relative displacements, which allow us to map the <span class="hlt">strain</span> at different length scales. We applied the MSSM technique to study <span class="hlt">strain</span> partitioning during deformation creep of Carrara marble and San Carlos olivine at a confining pressure, Pc, of 300 MPa and homologous temperatures of 0.3 to 0.6. We measured the local <span class="hlt">strain</span> and <span class="hlt">strain</span> heterogeneity produced during creep deformation of split cylinders of Carrara marble under conventional triaxial loading to inelastic <span class="hlt">strains</span> of 11 to 36% at a <span class="hlt">strain</span> rate of 3x10-5s-1, Pc = 300 MPa and 400o < T <700oC. We conclude that the evolution of deformation structures in marble takes place over a substantial interval in <span class="hlt">strain</span> and that the duration of this interval depends on <span class="hlt">strain</span> rate, temperature, and pressure. Our first results on <span class="hlt">strain</span> mapping of olivine deformed at T = 1150oC and Pc = 300 MPa demonstrate promise for characterizing intragranular <span class="hlt">strain</span> and better defining the contribution of grain boundary sliding to the total <span class="hlt">strain</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19201435','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19201435"><span>Principal component analysis of shear <span class="hlt">strain</span> effects.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Hao; Varghese, Tomy</p> <p>2009-05-01</p> <p>Shear stresses are always present during quasi-static <span class="hlt">strain</span> imaging, since tissue slippage occurs along the lateral and elevational directions during an axial deformation. Shear stress components along the axial deformation axes add to the axial deformation while perpendicular components introduce both lateral and elevational rigid motion and deformation artifacts into the estimated axial and lateral <span class="hlt">strain</span> tensor images. A clear understanding of these artifacts introduced into the normal and shear <span class="hlt">strain</span> tensor images with shear deformations is essential. In addition, signal processing techniques for improved depiction of the <span class="hlt">strain</span> distribution is required. In this paper, we evaluate the impact of artifacts introduced due to lateral shear deformations on the normal <span class="hlt">strain</span> tensors estimated by varying the lateral shear angle during an axial deformation. Shear <span class="hlt">strains</span> are quantified using the lateral shear angle during the applied deformation. Simulation and experimental validation using uniformly elastic and single inclusion phantoms were performed. Variations in the elastographic signal-to-noise and contrast-to-noise ratios for axial deformations ranging from 0% to 5%, and for lateral deformations ranging from 0 to 5 degrees were evaluated. Our results demonstrate that the first and second principal component <span class="hlt">strain</span> images provide higher signal-to-noise ratios of 20 dB with simulations and 10 dB under experimental conditions and contrast-to-noise ratio levels that are at least 20 dB higher when compared to the axial and lateral <span class="hlt">strain</span> tensor images, when only lateral shear deformations are applied. For small axial deformations, the lateral shear deformations significantly reduces <span class="hlt">strain</span> image quality, however the first principal component provides about a 1-2dB improvement over the axial <span class="hlt">strain</span> tensor image. Lateral shear deformations also significantly increase the noise level in the axial and lateral <span class="hlt">strain</span> tensor images with larger axial deformations</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18830403','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18830403"><span>Amerindian Helicobacter pylori <span class="hlt">strains</span> go extinct, as european <span class="hlt">strains</span> expand their host range.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Domínguez-Bello, Maria G; Pérez, Maria E; Bortolini, Maria C; Salzano, Francisco M; Pericchi, Luis R; Zambrano-Guzmán, Orlisbeth; Linz, Bodo</p> <p>2008-10-02</p> <p>We studied the diversity of bacteria and host in the H. pylori-human model. The human indigenous bacterium H. pylori diverged along with humans, into African, European, Asian and Amerindian groups. Of these, Amerindians have the least genetic diversity. Since niche diversity widens the sets of resources for colonizing species, we predicted that the Amerindian H. pylori <span class="hlt">strains</span> would be the least diverse. We analyzed the multilocus sequence (7 housekeeping genes) of 131 <span class="hlt">strains</span>: 19 cultured from Africans, 36 from Spanish, 11 from Koreans, 43 from Amerindians and 22 from South American Mestizos. We found that all <span class="hlt">strains</span> that had been cultured from Africans were African <span class="hlt">strains</span> (hpAfrica1), all from Spanish were European (hpEurope) and all from Koreans were hspEAsia but that Amerindians and Mestizos carried mixed <span class="hlt">strains</span>: hspAmerind and hpEurope <span class="hlt">strains</span> had been cultured from Amerindians and hpEurope and hpAfrica1 were cultured from Mestizos. The least genetically diverse H. pylori <span class="hlt">strains</span> were hspAmerind. <span class="hlt">Strains</span> hpEurope were the most diverse and showed remarkable multilocus sequence mosaicism (indicating recombination). The lower genetic structure in hpEurope <span class="hlt">strains</span> is consistent with colonization of a diversity of hosts. If diversity is important for the success of H. pylori, then the low diversity of Amerindian <span class="hlt">strains</span> might be linked to their apparent tendency to disappear. This suggests that Amerindian <span class="hlt">strains</span> may lack the needed diversity to survive the diversity brought by non-Amerindian hosts.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2551748','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2551748"><span>Amerindian Helicobacter pylori <span class="hlt">Strains</span> Go Extinct, as European <span class="hlt">Strains</span> Expand Their Host Range</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Domínguez-Bello, Maria G.; Pérez, Maria E.; Bortolini, Maria C.; Salzano, Francisco M.; Pericchi, Luis R.; Zambrano-Guzmán, Orlisbeth; Linz, Bodo</p> <p>2008-01-01</p> <p>We studied the diversity of bacteria and host in the H. pylori-human model. The human indigenous bacterium H. pylori diverged along with humans, into African, European, Asian and Amerindian groups. Of these, Amerindians have the least genetic diversity. Since niche diversity widens the sets of resources for colonizing species, we predicted that the Amerindian H. pylori <span class="hlt">strains</span> would be the least diverse. We analyzed the multilocus sequence (7 housekeeping genes) of 131 <span class="hlt">strains</span>: 19 cultured from Africans, 36 from Spanish, 11 from Koreans, 43 from Amerindians and 22 from South American Mestizos. We found that all <span class="hlt">strains</span> that had been cultured from Africans were African <span class="hlt">strains</span> (hpAfrica1), all from Spanish were European (hpEurope) and all from Koreans were hspEAsia but that Amerindians and Mestizos carried mixed <span class="hlt">strains</span>: hspAmerind and hpEurope <span class="hlt">strains</span> had been cultured from Amerindians and hpEurope and hpAfrica1 were cultured from Mestizos. The least genetically diverse H. pylori <span class="hlt">strains</span> were hspAmerind. <span class="hlt">Strains</span> hpEurope were the most diverse and showed remarkable multilocus sequence mosaicism (indicating recombination). The lower genetic structure in hpEurope <span class="hlt">strains</span> is consistent with colonization of a diversity of hosts. If diversity is important for the success of H. pylori, then the low diversity of Amerindian <span class="hlt">strains</span> might be linked to their apparent tendency to disappear. This suggests that Amerindian <span class="hlt">strains</span> may lack the needed diversity to survive the diversity brought by non-Amerindian hosts. PMID:18830403</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28049090','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28049090"><span>New regime in the mechanical behavior of skin: <span class="hlt">strain</span>-softening occurring before <span class="hlt">strain</span>-hardening.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nicolle, S; Decorps, J; Fromy, B; Palierne, J-F</p> <p>2017-05-01</p> <p>We report linear and non-linear shear tests on rat skin, evidencing a <span class="hlt">strain</span>-softening regime, from 1% to 50% <span class="hlt">strain</span>, followed by a strong <span class="hlt">strain</span>-hardening regime, leading to a 'deck chair-shaped' stress-<span class="hlt">strain</span> curve. The <span class="hlt">strain</span>-softening regime was never reported as such in the literature, possibly mistaken for the linear regime in experiments starting above 1% deformation. The time-dependent response is akin to that of a gel, with a power-law frequency-dependent dynamic shear modulus ranging from ~5.6kPa to ~10kPa between 0.1Hz and 10Hz. We present an analytical non-linear viscoelastic model that accounts for both time-dependent and <span class="hlt">strain</span>-dependent features of the skin. This eight-parameter model extends the one we proposed for parenchymatous organs by including <span class="hlt">strain</span>-softening.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008IJMPB..22.1255K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008IJMPB..22.1255K"><span>Dynamic Tensile Properties of Iron and Steels for a Wide Range of <span class="hlt">Strain</span> Rates and <span class="hlt">Strain</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kojima, Nobusato; Hayashi, Hiroyuki; Yamamoto, Terumi; Mimura, Koji; Tanimura, Shinji</p> <p></p> <p>The tensile stress-<span class="hlt">strain</span> curves of iron and a variety of steels, covering a wide range of strength level, over a wide <span class="hlt">strain</span> rate range on the order of 10-3 ~ 103 s-1, were obtained systematically by using the Sensing Block Type High Speed Material Testing System (SBTS, Saginomiya). Through intensive analysis of these results, the <span class="hlt">strain</span> rate sensitivity of the flow stress for the large <span class="hlt">strain</span> region, including the viscous term at high <span class="hlt">strain</span> rates, the true fracture strength and the true fracture <span class="hlt">strain</span> were cleared for the material group of the ferrous metals. These systematical data may be useful to develop a practical constitutive model for computer codes, including a fracture criterion for simulations of the dynamic behavior in crash worthiness studies and of work-pieces subjected to dynamic plastic working for a wide <span class="hlt">strain</span> rate range.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23030102','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23030102"><span>Anisotropic <span class="hlt">strain</span> enhanced hydrogen solubility in bcc metals: the independence on the sign of <span class="hlt">strain</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhou, Hong-Bo; Jin, Shuo; Zhang, Ying; Lu, Guang-Hong; Liu, Feng</p> <p>2012-09-28</p> <p>When an impurity is doped in a solid, it inevitably induces a local stress, tending to expand or contract the lattice. Consequently, <span class="hlt">strain</span> can be applied to change the solubility of impurity in a solid. Generally, the solubility responds to <span class="hlt">strain</span> "monotonically," increasing (decreasing) with the tensile (compressive) <span class="hlt">strain</span> if the impurity induces a compressive stress or vice versa. Using first-principles calculations, however, we discovered that the H solubility can be enhanced by anisotropic <span class="hlt">strain</span> in some bcc metals, almost independent of the sign of <span class="hlt">strain</span>. This anomalous behavior is found to be caused by a continuous change of H location induced by anisotropic <span class="hlt">strain</span>. Our finding suggests a cascading effect of H bubble formation in bcc metals: the H solution leads to H bubble formation that induces anisotropic <span class="hlt">strain</span> that in turn enhances H solubility to further facilitate bubble growth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19770049578&hterms=wrench+materials&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dwrench%2Bmaterials','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19770049578&hterms=wrench+materials&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dwrench%2Bmaterials"><span>A CW ultrasonic bolt-<span class="hlt">strain</span> monitor</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Heyman, J. S.</p> <p>1977-01-01</p> <p>There exists a need for a relatively inexpensive system for measuring <span class="hlt">strain</span> in bolts. The torque wrench is one technique for <span class="hlt">straining</span> bolts which has been widely applied. Unfortunately, friction in the bolt threads and between the nut and the work tend to make such a simple system inaccurate. In practice, a torque wrench is unacceptable for many situations where <span class="hlt">strain</span> is critical. In this article, an ultrasonic technique is described which can indicate changes in bolt <span class="hlt">strain</span> to better than one part in 10,000. The technique is based on the one-dimensional propagating-ultrasonic-wave model and uses a new ultrasonic instrument called a Reflection Oscillator Ultrasonic Spectrometer which is a closed-loop feedback marginal-oscillator system that frequency locks the device to the peak of a mechanical resonance in the bolt. The instrument indicates a shift in the bolt resonance frequency due to elongation and changes in velocity of sound due to <span class="hlt">strain</span>. Data are presented comparing a standard torque wrench to the ultrasonic monitor for different measured stresses on the bolt as well as for different bolt conditions. The <span class="hlt">strain</span> instrument can be used to monitor changing stresses, to measure material properties and may be applied as a <span class="hlt">strain</span> gage or load cell.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20999337','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20999337"><span>Pressure effects on nonpremixed <span class="hlt">strained</span> flames</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pons, Laetitia; Darabiha, Nasser; Candel, Sebastien</p> <p>2008-01-15</p> <p>This article deals with the effect of pressure on the structure and consumption rate of nonpremixed <span class="hlt">strained</span> flames. An analysis based on the fast chemistry limit indicates that the flame thickness is inversely proportional to the square root of pressure and that the flame structure may be described in terms of a similarity variable that scales like the product of pressure and the <span class="hlt">strain</span> rate to the power 1/2. This scaling rule also applies to flames submitted to a time-variable <span class="hlt">strain</span> rate provided that the frequencies characterizing these changes are low compared to the mean <span class="hlt">strain</span> rate. It is also confirmed that reactants consumption rates per unit flame surface vary like the square root of pressure and that this rule holds for time-variable <span class="hlt">strain</span> rates of arbitrary nature. Complex chemistry calculations carried out over a broad range of operating pressures indicate that the pressure dependences deduced analytically are remarkably accurate and can be used for a broad range of <span class="hlt">strain</span> rates, excluding values in the near vicinity of extinction conditions, where finite rate chemistry effects become important and influence the flame response to pressure. Thus, it appears that the pressure exponent characterizing the heat release rate in nonpremixed <span class="hlt">strained</span> flames is essentially constant and equal to 1/2. This exponent is independent of finite rate chemistry effects, except when conditions are close to extinction. (author)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007IJMSp.259..140K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007IJMSp.259..140K"><span>Specific identification of Bacillus anthracis <span class="hlt">strains</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Krishnamurthy, Thaiya; Deshpande, Samir; Hewel, Johannes; Liu, Hongbin; Wick, Charles H.; Yates, John R., III</p> <p>2007-01-01</p> <p>Accurate identification of human pathogens is the initial vital step in treating the civilian terrorism victims and military personnel afflicted in biological threat situations. We have applied a powerful multi-dimensional protein identification technology (MudPIT) along with newly generated software termed Profiler to identify the sequences of specific proteins observed for few <span class="hlt">strains</span> of Bacillus anthracis, a human pathogen. Software termed Profiler was created to initially screen the MudPIT data of B. anthracis <span class="hlt">strains</span> and establish the observed proteins specific for its <span class="hlt">strains</span>. A database was also generated using Profiler containing marker proteins of B. anthracis and its <span class="hlt">strains</span>, which in turn could be used for detecting the organism and its corresponding <span class="hlt">strains</span> in samples. Analysis of the unknowns by our methodology, combining MudPIT and Profiler, led to the accurate identification of the anthracis <span class="hlt">strains</span> present in samples. Thus, a new approach for the identification of B. anthracis <span class="hlt">strains</span> in unknown samples, based on the molecular mass and sequences of marker proteins, has been ascertained.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28773023','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28773023"><span>Ultra High <span class="hlt">Strain</span> Rate Nanoindentation Testing.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sudharshan Phani, Pardhasaradhi; Oliver, Warren Carl</p> <p>2017-06-17</p> <p><span class="hlt">Strain</span> rate dependence of indentation hardness has been widely used to study time-dependent plasticity. However, the currently available techniques limit the range of <span class="hlt">strain</span> rates that can be achieved during indentation testing. Recent advances in electronics have enabled nanomechanical measurements with very low noise levels (sub nanometer) at fast time constants (20 µs) and high data acquisition rates (100 KHz). These capabilities open the doors for a wide range of ultra-fast nanomechanical testing, for instance, indentation testing at very high <span class="hlt">strain</span> rates. With an accurate dynamic model and an instrument with fast time constants, step load tests can be performed which enable access to indentation <span class="hlt">strain</span> rates approaching ballistic levels (i.e., 4000 1/s). A novel indentation based testing technique involving a combination of step load and constant load and hold tests that enables measurement of <span class="hlt">strain</span> rate dependence of hardness spanning over seven orders of magnitude in <span class="hlt">strain</span> rate is presented. A simple analysis is used to calculate the equivalent uniaxial response from indentation data and compared to the conventional uniaxial data for commercial purity aluminum. Excellent agreement is found between the indentation and uniaxial data over several orders of magnitude of <span class="hlt">strain</span> rate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26865336','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26865336"><span>Antimicrobial activity of lactobacillus <span class="hlt">strains</span> against uropathogens.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shim, Yoon Hee; Lee, Seung Joo; Lee, Jung Won</p> <p>2016-10-01</p> <p>The use of lactobacillus probiotics has been proposed as an alternative to prophylactic antibiotics for preventing urinary tract infection (UTI) in the era of antibiotic resistance. In this study, the antimicrobial activity of lactobacillus <span class="hlt">strains</span> against uropathogens, was evaluated and compared with that of antibiotics. To evaluate inhibitory activities of lactobacilli against uropathogens, six lactobacillus <span class="hlt">strains</span> (L. gasseri, L. rhamnosus, L. acidophilus, L. plantarum, L. paracasei, L. acidophilus) and four representative uropathogens of infantile UTI (extended-spectrum beta-lactamase [ESBL](-) Escherichia coli, ESBL(+) E. coli, Proteus vulgaris, Enterococcus fecalis) were selected. Lactobacillus <span class="hlt">strain</span> in vitro inhibition of each uropathogen was evaluated on MRS agar well diffusion assay and compared with that of commercial antibiotic discs. Average inhibitory zone for each of the six lactobacillus <span class="hlt">strains</span> against the four uropathogens showed slightly different but consistent inhibition (inhibitory zone diameter, 10.5-20.0 mm). This was different to that of the antibiotic discs, which had a wider range of inhibition (inhibitory zone diameter, <6.0-27.5 mm) depending on the uropathogen resistance pattern. The inhibitory zone of the six lactobacillus <span class="hlt">strains</span> was between that of sensitive and resistant antibiotics (P < 0.05). Lactobacillus <span class="hlt">strains</span> had similar moderate antimicrobial activities against uropathogens. Further research is needed to ascertain the <span class="hlt">strains</span> with the best probiotic potential. © 2016 Japan Pediatric Society.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006PMB....51.5245T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006PMB....51.5245T"><span>Resolution of axial shear <span class="hlt">strain</span> elastography</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thitaikumar, Arun; Righetti, Raffaella; Krouskop, Thomas A.; Ophir, Jonathan</p> <p>2006-10-01</p> <p>The technique of mapping the local axial component of the shear <span class="hlt">strain</span> due to quasi-static axial compression is defined as axial shear <span class="hlt">strain</span> elastography. In this paper, the spatial resolution of axial shear <span class="hlt">strain</span> elastography is investigated through simulations, using an elastically stiff cylindrical lesion embedded in a homogeneously softer background. Resolution was defined as the smallest size of the inclusion for which the <span class="hlt">strain</span> value at the inclusion/background interface was greater than the average of the axial shear <span class="hlt">strain</span> values at the interface and inside the inclusion. The resolution was measured from the axial shear <span class="hlt">strain</span> profile oriented at 45° to the axis of beam propagation, due to the absence of axial shear <span class="hlt">strain</span> along the normal directions. The effects of the ultrasound system parameters such as bandwidth, beamwidth and transducer element pitch along with signal processing parameters such as correlation window length (W) and axial shift (ΔW) on the estimated resolution were investigated. The results show that the resolution (at 45° orientation) is determined by the bandwidth and the beamwidth. However, the upper bound on the resolution is limited by the larger of the beamwidth and the window length, which is scaled inversely to the bandwidth. The results also show that the resolution is proportional to the pitch and not significantly affected by the axial window shift.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4631365','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4631365"><span>Highly Invasive Listeria monocytogenes <span class="hlt">Strains</span> Have Growth and Invasion Advantages in <span class="hlt">Strain</span> Competition</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Manthou, Evanthia; Ciolacu, Luminita; Wagner, Martin; Skandamis, Panagiotis N.</p> <p>2015-01-01</p> <p>Multiple Listeria monocytogenes <span class="hlt">strains</span> can be present in the same food sample; moreover, infection with more than one L. monocytogenes <span class="hlt">strain</span> can also occur. In this study we investigated the impact of <span class="hlt">strain</span> competition on the growth and in vitro virulence potential of L. monocytogenes. We identified two strong competitor <span class="hlt">strains</span>, whose growth was not (or only slightly) influenced by the presence of other <span class="hlt">strains</span> and two weak competitor <span class="hlt">strains</span>, which were outcompeted by other <span class="hlt">strains</span>. Cell contact was essential for growth inhibition. In vitro virulence assays using human intestinal epithelial Caco2 cells showed a correlation between the invasion efficiency and growth inhibition: the strong growth competitor <span class="hlt">strains</span> showed high invasiveness. Moreover, invasion efficiency of the highly invasive <span class="hlt">strain</span> was further increased in certain combinations by the presence of a low invasive <span class="hlt">strain</span>. In all tested combinations, the less invasive <span class="hlt">strain</span> was outcompeted by the higher invasive <span class="hlt">strain</span>. Studying the effect of cell contact on in vitro virulence competition revealed a complex pattern in which the observed effects depended only partially on cell-contact suggesting that competition occurs at two different levels: i) during co-cultivation prior to infection, which might influence the expression of virulence factors, and ii) during infection, when bacterial cells compete for the host cell. In conclusion, we show that growth of L. monocytogenes can be inhibited by <span class="hlt">strains</span> of the same species leading potentially to biased recovery during enrichment procedures. Furthermore, the presence of more than one L. monocytogenes <span class="hlt">strain</span> in food can lead to increased infection rates due to synergistic effects on the virulence potential. PMID:26529510</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26529510','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26529510"><span>Highly Invasive Listeria monocytogenes <span class="hlt">Strains</span> Have Growth and Invasion Advantages in <span class="hlt">Strain</span> Competition.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zilelidou, Evangelia A; Rychli, Kathrin; Manthou, Evanthia; Ciolacu, Luminita; Wagner, Martin; Skandamis, Panagiotis N</p> <p>2015-01-01</p> <p>Multiple Listeria monocytogenes <span class="hlt">strains</span> can be present in the same food sample; moreover, infection with more than one L. monocytogenes <span class="hlt">strain</span> can also occur. In this study we investigated the impact of <span class="hlt">strain</span> competition on the growth and in vitro virulence potential of L. monocytogenes. We identified two strong competitor <span class="hlt">strains</span>, whose growth was not (or only slightly) influenced by the presence of other <span class="hlt">strains</span> and two weak competitor <span class="hlt">strains</span>, which were outcompeted by other <span class="hlt">strains</span>. Cell contact was essential for growth inhibition. In vitro virulence assays using human intestinal epithelial Caco2 cells showed a correlation between the invasion efficiency and growth inhibition: the strong growth competitor <span class="hlt">strains</span> showed high invasiveness. Moreover, invasion efficiency of the highly invasive <span class="hlt">strain</span> was further increased in certain combinations by the presence of a low invasive <span class="hlt">strain</span>. In all tested combinations, the less invasive <span class="hlt">strain</span> was outcompeted by the higher invasive <span class="hlt">strain</span>. Studying the effect of cell contact on in vitro virulence competition revealed a complex pattern in which the observed effects depended only partially on cell-contact suggesting that competition occurs at two different levels: i) during co-cultivation prior to infection, which might influence the expression of virulence factors, and ii) during infection, when bacterial cells compete for the host cell. In conclusion, we show that growth of L. monocytogenes can be inhibited by <span class="hlt">strains</span> of the same species leading potentially to biased recovery during enrichment procedures. Furthermore, the presence of more than one L. monocytogenes <span class="hlt">strain</span> in food can lead to increased infection rates due to synergistic effects on the virulence potential.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRB..121.5736Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRB..121.5736Q"><span>Heterogeneity of inelastic <span class="hlt">strain</span> during creep of Carrara marble: Microscale <span class="hlt">strain</span> measurement technique</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Quintanilla-Terminel, Alejandra; Evans, Brian</p> <p>2016-08-01</p> <p>We combined the split cylinder technique with microfabrication technology to observe <span class="hlt">strain</span> heterogeneities that were produced during high-pressure transient creep of Carrara marble. Samples were patterned with a custom-designed grid of markers spaced 10 µm apart and containing an embedded coordinate system. The microscale <span class="hlt">strain</span> measurement (MSSM) technique described here allowed us to analyze the local <span class="hlt">strain</span> distribution with unprecedented detail over large regions. The description of the <span class="hlt">strain</span> field is a function of the area over which <span class="hlt">strain</span> is being computed. The scale at which the <span class="hlt">strain</span> field can be considered homogeneous can provide insight into the deformation processes taking place. At 400-500°C, when twinning production is prolific, we observe highly <span class="hlt">strained</span> bands that span several grains. One possible cause for the multigrain bands is the need to relieve <span class="hlt">strain</span> incompatibilities that result when twins impinge on neighboring grains. At 600-700°C, the <span class="hlt">strain</span> fields are still quite heterogeneous, and local <span class="hlt">strain</span> varies substantially within grains and near grain boundaries, but the multigrain slip bands are not present. Deformation is concentrated in much smaller areas within grains and along some grain boundaries. The disappearance of the multigrain slip bands occurs when the deformation conditions allow additional slip systems to be activated. At 600°C, when the total <span class="hlt">strain</span> is varied from 0.11 to 0.36, the spatial scale of the heterogeneity does not vary, but there are increases in the standard deviation of the distribution of local <span class="hlt">strains</span> normalized by the total <span class="hlt">strain</span>; thus, we conclude that the microstructure does not achieve a steady state in this <span class="hlt">strain</span> interval.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27829542','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27829542"><span>Development of intra-<span class="hlt">strain</span> self-cloning procedure for breeding baker's yeast <span class="hlt">strains</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nakagawa, Youji; Ogihara, Hiroyuki; Mochizuki, Chisato; Yamamura, Hideki; Iimura, Yuzuru; Hayakawa, Masayuki</p> <p>2017-03-01</p> <p>Previously reported self-cloning procedures for breeding of industrial yeast <span class="hlt">strains</span> require DNA from other <span class="hlt">strains</span>, plasmid DNA, or mutagenesis. Therefore, we aimed to construct a self-cloning baker's yeast <span class="hlt">strain</span> that exhibits freeze tolerance via an improved self-cloning procedure. We first disrupted the URA3 gene of a prototrophic baker's yeast <span class="hlt">strain</span> without the use of any marker gene, resulting in a Δura3 homozygous disruptant. Then, the URA3 gene of the parental baker's yeast <span class="hlt">strain</span> was used as a selection marker to introduce the constitutive TDH3 promoter upstream of the PDE2 gene encoding high-affinity cyclic AMP phosphodiesterase. This self-cloning procedure was performed without using DNA from other Saccharomyces cerevisiae <span class="hlt">strains</span>, plasmid DNA, or mutagenesis and was therefore designated an intra-<span class="hlt">strain</span> self-cloning procedure. Using this self-cloning procedure, we succeeded in producing self-cloning baker's yeast <span class="hlt">strains</span> that harbor the TDH3p-PDE2 gene heterozygously and homozygously, designated TDH3p-PDE2 hetero and TDH3p-PDE2 homo <span class="hlt">strains</span>, respectively. These self-cloning <span class="hlt">strains</span> expressed much higher levels of PDE2 mRNA than the parental <span class="hlt">strain</span> and exhibited higher viability after freeze stress, as well as higher fermentation ability in frozen dough, when compared with the parental <span class="hlt">strain</span>. The TDH3p-PDE2 homo <span class="hlt">strain</span> was genetically more stable than the TDH3p-PDE2 hetero <span class="hlt">strain</span>. These results indicate that both heterozygous and homozygous <span class="hlt">strains</span> of self-cloning PDE2-overexpressing freeze-tolerant <span class="hlt">strains</span> of industrial baker's yeast can be prepared using the intra-<span class="hlt">strain</span> self-cloning procedure, and, from a practical viewpoint, the TDH3p-PDE2 homo <span class="hlt">strain</span> constructed in this study is preferable to the TDH3p-PDE2 hetero <span class="hlt">strain</span> for frozen dough baking. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10888638','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10888638"><span>Genetic diversity among Lassa virus <span class="hlt">strains</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bowen, M D; Rollin, P E; Ksiazek, T G; Hustad, H L; Bausch, D G; Demby, A H; Bajani, M D; Peters, C J; Nichol, S T</p> <p>2000-08-01</p> <p>The arenavirus Lassa virus causes Lassa fever, a viral hemorrhagic fever that is endemic in the countries of Nigeria, Sierra Leone, Liberia, and Guinea and perhaps elsewhere in West Africa. To determine the degree of genetic diversity among Lassa virus <span class="hlt">strains</span>, partial nucleoprotein (NP) gene sequences were obtained from 54 <span class="hlt">strains</span> and analyzed. Phylogenetic analyses showed that Lassa viruses comprise four lineages, three of which are found in Nigeria and the fourth in Guinea, Liberia, and Sierra Leone. Overall <span class="hlt">strain</span> variation in the partial NP gene sequence was found to be as high as 27% at the nucleotide level and 15% at the amino acid level. Genetic distance among Lassa <span class="hlt">strains</span> was found to correlate with geographic distance rather than time, and no evidence of a "molecular clock" was found. A method for amplifying and cloning full-length arenavirus S RNAs was developed and used to obtain the complete NP and glycoprotein gene (GP1 and GP2) sequences for two representative Nigerian <span class="hlt">strains</span> of Lassa virus. Comparison of full-length gene sequences for four Lassa virus <span class="hlt">strains</span> representing the four lineages showed that the NP gene (up to 23.8% nucleotide difference and 12.0% amino acid difference) is more variable than the glycoprotein genes. Although the evolutionary order of descent within Lassa virus <span class="hlt">strains</span> was not completely resolved, the phylogenetic analyses of full-length NP, GP1, and GP2 gene sequences suggested that Nigerian <span class="hlt">strains</span> of Lassa virus were ancestral to <span class="hlt">strains</span> from Guinea, Liberia, and Sierra Leone. Compared to the New World arenaviruses, Lassa and the other Old World arenaviruses have either undergone a shorter period of diverisification or are evolving at a slower rate. This study represents the first large-scale examination of Lassa virus genetic variation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JMPSo..56..360P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JMPSo..56..360P"><span>Recoverable <span class="hlt">strains</span> in composite shape memory alloys</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peigney, Michaël</p> <p></p> <p>New upper bounds are proposed for a generic problem of geometric compatibility, which covers the problem of bounding the effective recoverable <span class="hlt">strains</span> in composite shape memory alloys (SMAs), such as polycrystalline SMAs or rigidly reinforced SMAs. Both the finite deformation and infinitesimal <span class="hlt">strain</span> frameworks are considered. The methodology employed is a generalization of a homogenization approach introduced by Milton and Serkov [2000. Bounding the current in nonlinear conducting composites. J. Mech. Phys. Solids 48, 1295-1324] for nonlinear composites in infinitesimal <span class="hlt">strains</span>. Some analytical and numerical examples are given to illustrate the method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10543843','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10543843"><span>Genotypic diversity among Brevibacillus laterosporus <span class="hlt">strains</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zahner, V; Rabinovitch, L; Suffys, P; Momen, H</p> <p>1999-11-01</p> <p>In comparison with other entomopathogenic Bacillus species, the genome of Brevibacillus laterosporus is poorly characterized. The aim of this study was to examine genetic variability in B. laterosporus by using a range of typing methodologies. <span class="hlt">Strains</span> of B. laterosporus were examined for variation in 13 chromosomal genes encoding enzymes by multilocus enzyme electrophoresis. Optimal conditions of pulsed-field gel electrophoresis and randomly amplified polymorphic DNA were established that allowed analysis of the genome of B. laterosporus. None of these techniques allowed the identification of a convenient molecular marker for entomopathogenic <span class="hlt">strains</span>, although one specific primer amplified only DNA from almost all mosquitocidal <span class="hlt">strains</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvB..95q4517L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvB..95q4517L"><span>Fractional Josephson effect in nonuniformly <span class="hlt">strained</span> graphene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, Shu-Ping; Nandi, Debaleena; Marsiglio, Frank; Maciejko, Joseph</p> <p>2017-05-01</p> <p>Nonuniform <span class="hlt">strain</span> distributions in a graphene lattice can give rise to uniform pseudomagnetic fields and associated pseudo-Landau levels without breaking time-reversal symmetry. We demonstrate that by inducing superconductivity in a nonuniformly <span class="hlt">strained</span> graphene sheet, the lowest pseudo-Landau levels split by a pairing gap can be inverted by changing the sign of the pairing potential. As a consequence of this inversion, we predict that a Josephson π junction deposited on top of a <span class="hlt">strained</span> graphene sheet exhibits one-dimensional gapless modes propagating along the junction. These gapless modes mediate single electron tunneling across the junction, giving rise to the 4 π -periodic fractional Josephson effect.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/6239469','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/6239469"><span>Differentiation of pathogenic and saprophytic leptospira <span class="hlt">strains</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bazovská, S; Kmety, E; Rak, J</p> <p>1984-09-01</p> <p>Comparative studies of 249 pathogenic and 80 saprophytic leptospira <span class="hlt">strains</span>, including 2 <span class="hlt">strains</span> of the illini type, using the 8-azaguanine test, growth at 13 degrees C and growth on trypticase soy broth revealed their good differentiating potency if the recommended conditions were carefully observed. The same results were obtained by a simple hemolytic test using sheep and rat blood cells, having the advantage of providing results within 24 h. This test is suggested to replace the 8-azaguanine and the growth test at 13 degrees C. In these investigations, the first European <span class="hlt">strain</span> of the illini type was recognized.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AGUFM.V12A0552Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AGUFM.V12A0552Q"><span>Microstructural Analysis of Welding: Deformation and <span class="hlt">Strain</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Quane, S. L.; Russell, K.</p> <p>2003-12-01</p> <p>Welding in pyroclastic deposits involves the sintering, compaction and flattening of hot glassy particles and is attended by systematic changes in physical properties. Welded materials contain implicit information regarding the total accumulated <span class="hlt">strain</span> as well as the mechanisms of deformation. Here, we use detailed microstructural analysis of synthetic and natural welded materials to make quantitative estimates of <span class="hlt">strain</span> and constrain the rheology of these materials during the welding process. Part one of our study comprises microstructural analysis of end products from unconfined high temperature deformation experiments on sintered cores of soda-lime silica glass spheres. This analogue material has relatively simple and well-characterized starting properties. Furthermore, the initially spherical shapes of particles provide excellent <span class="hlt">strain</span> markers. Experiments were run at a variety of temperatures, <span class="hlt">strain</span> rates and stresses resulting in end products with varying degrees of total <span class="hlt">strain</span>. The nature of <span class="hlt">strain</span> partitioning and accumulation are evaluated using image analysis techniques on scanned images and photomicrographs of thin sections cut perpendicular to the loading direction of each experimental product. Shapes of the individual deformed particles (e.g., oblate spheroids) were determined and the Scion image analysis program was used to create a best-fit ellipse for each particle. Statistics collected on each particle include: axial dimension (a), vertical dimension (c) and angle from the horizontal. The data are used to calculate the oblateness of each particle (1-c/a) and the angle of deformation induced foliation. Furthermore, the relative proportions of visible blue epoxy in the sample scans determine bulk porosity. The average oblateness of the particles is a direct, independent measure of the accumulated <span class="hlt">strain</span> in each sample. Results indicate that these measured values are equal to calculated theoretical values of oblateness for spheroids undergoing the</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9634E..7VN','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9634E..7VN"><span>Lithium batteries temperature and <span class="hlt">strain</span> fiber monitoring</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nascimento, Micael; Novais, Susana; Leitão, Cátia; Domingues, M. Fátima; Alberto, Nélia; Antunes, Paulo; Pinto, João. L.</p> <p>2015-09-01</p> <p>Fiber Bragg grating sensors were attached to the surface of a rechargeable lithium battery in order to monitor its thermal and <span class="hlt">strain</span> fluctuations through charge and different discharge C rates. During the discharge process above 1C, it were observed, a temperature and <span class="hlt">strain</span> fluctuations of a 4.12 +/- 0.67 °C and 24.64 +/- 6.02 μɛ, respectively. In the regular charge process, a temperature and <span class="hlt">strain</span> variation of 1.03 +/- 0.67 °C and 15.86 +/- 6.02 μɛ, were detected.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21506808','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21506808"><span><span class="hlt">Strain</span> Determination Using Electron Backscatter Diffraction</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Krause, M.; Graff, A.; Altmann, F.</p> <p>2010-11-24</p> <p>In the present paper we demonstrate the use of electron backscatter diffraction (EBSD) for high resolution elastic <span class="hlt">strain</span> determination. Here, we focus on analysis methods based on determination of small shifts in EBSD pattern with respect to a reference pattern using cross-correlation algorithms. Additionally we highlight the excellent spatial and depth resolution of EBSD and introduce the use of simulated diffraction patterns based on dynamical diffraction theory for sensitivity estimation. Moreover the potential of EBSD for <span class="hlt">strain</span> analysis of <span class="hlt">strained</span> thin films with particular emphasis on appropriate target preparation which respect to occurring lattice defects is demonstrated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5378936','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5378936"><span><span class="hlt">Strain</span> and <span class="hlt">strain</span> rate echocardiography in children with Wilson’s disease</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Cemşit, Karakurt; Serkan, Çelik; Ayşe, Selimoğlu; İlknur, Varol; Hamza, Karabiber; Saim, Yoloğlu</p> <p>2016-01-01</p> <p>Summary Objective This study aimed to evaluate <span class="hlt">strain</span> and <span class="hlt">strain</span> rate echocardiography in children with Wilson’s disease to detect early cardiac dysfunction. Methods In this study, 21 patients with Wilson’s disease and a control group of 20 age- and gender-matched healthy children were included. All the patients and the control group were evaluated with two-dimensional (2D) and colour-coded conventional transthoracic echocardiography by the same paediatric cardiologist using the same echocardiography machine (Vivid E9, GE Healthcare, Norway) in standard precordial positions, according to the American Society of Echocardiography recommendations. 2D <span class="hlt">strain</span> and <span class="hlt">strain</span> rate echocardiography were performed after the ECG probes of the echocardiography machine were adjusted for ECG monitoring. Longitudinal, transverse and radial <span class="hlt">strain</span>, and <span class="hlt">strain</span> rate were assessed from six basal and six mid-ventricular segments of the left ventricle, as recommended by the American Society of Echocardiography. Results Left ventricular wall thickness, systolic and diastolic diameters, left ventricular diameters normalised to body surface area, end-systolic and end-diastolic volumes, cardiac output and cardiac index values were within normal limits and statistically similar in the patient and control groups (p < 0.05). Global <span class="hlt">strain</span> and <span class="hlt">strain</span> rate: the patient group had a statistically significant lower peak A longitudinal velocity of the left basal point and peak E longitudinal velocity of the left basal (VAbasR) point, and higher global peak A longitudinal/circumferential <span class="hlt">strain</span> rate (GSRa) compared to the corresponding values of the control group (p < 0.05). Radial <span class="hlt">strain</span> and <span class="hlt">strain</span> rate: end-systolic rotation [ROT (ES)] was statistically significantly lower in the patient group (p < 0.05). Longitudinal <span class="hlt">strain</span> and <span class="hlt">strain</span> rate: end-systolic longitudinal <span class="hlt">strain</span> [SLSC (ES)] and positive peak transverse <span class="hlt">strain</span> (STSR peak P) were statistically significantly lower in the patient group (p</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19830010448','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19830010448"><span>A study of the effect of apparent <span class="hlt">strain</span> on thermal stress measurement for two types of elevated temperature <span class="hlt">strain</span> gages</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jenkins, J. M.</p> <p>1983-01-01</p> <p>A weldable type <span class="hlt">strain</span> gage was used to measure low level thermal stress in an elevated temperature environment. Foil <span class="hlt">strain</span> gages used in a comparative manner reveal that the apparent <span class="hlt">strain</span> of weldable <span class="hlt">strain</span> gages is not sufficiently known to acquire accurate low level thermal stress data. Apparent <span class="hlt">strain</span> data acquired from coupon tests reveals a large scatter in apparent <span class="hlt">strain</span> characteristics among the weldable <span class="hlt">strain</span> gages. It is concluded that apparent <span class="hlt">strain</span> data for individual weldable <span class="hlt">strain</span> gages must be required prior to installation if valid thermal stress data is to be obtained through the temperature range of room temperature to 755 K (900 F).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24267899','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24267899"><span>Rat <span class="hlt">Strain</span> Ontology: structured controlled vocabulary designed to facilitate access to <span class="hlt">strain</span> data at RGD.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nigam, Rajni; Munzenmaier, Diane H; Worthey, Elizabeth A; Dwinell, Melinda R; Shimoyama, Mary; Jacob, Howard J</p> <p>2013-11-22</p> <p>The Rat Genome Database (RGD) ( http://rgd.mcw.edu/) is the premier site for comprehensive data on the different <span class="hlt">strains</span> of the laboratory rat (Rattus norvegicus). The <span class="hlt">strain</span> data are collected from various publications, direct submissions from individual researchers, and rat providers worldwide. Rat <span class="hlt">strain</span>, substrain designation and nomenclature follow the Guidelines for Nomenclature of Mouse and Rat <span class="hlt">Strains</span>, instituted by the International Committee on Standardized Genetic Nomenclature for Mice. While symbols and names aid in identifying <span class="hlt">strains</span> correctly, the flat nature of this information prohibits easy search and retrieval, as well as other data mining functions. In order to improve these functionalities, particularly in ontology-based tools, the Rat <span class="hlt">Strain</span> Ontology (RS) was developed. The Rat <span class="hlt">Strain</span> Ontology (RS) reflects the breeding history, parental background, and genetic manipulation of rat <span class="hlt">strains</span>. This controlled vocabulary organizes <span class="hlt">strains</span> by type: inbred, outbred, chromosome altered, congenic, mutant and so on. In addition, under the chromosome altered category, <span class="hlt">strains</span> are organized by chromosome, and further by type of manipulations, such as mutant or congenic. This allows users to easily retrieve <span class="hlt">strains</span> of interest with modifications in specific genomic regions. The ontology was developed using the Open Biological and Biomedical Ontology (OBO) file format, and is organized on the Directed Acyclic Graph (DAG) structure. Rat <span class="hlt">Strain</span> Ontology IDs are included as part of the <span class="hlt">strain</span> report (RS: ######). As rat researchers are often unaware of the number of substrains or altered <span class="hlt">strains</span> within a breeding line, this vocabulary now provides an easy way to retrieve all substrains and accompanying information. Its usefulness is particularly evident in tools such as the PhenoMiner at RGD, where users can now easily retrieve phenotype measurement data for related <span class="hlt">strains</span>, <span class="hlt">strains</span> with similar backgrounds or those with similar introgressed regions. This</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9040E..15Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9040E..15Y"><span>A new radial <span class="hlt">strain</span> and <span class="hlt">strain</span> rate estimation method using autocorrelation for carotid artery</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ye, Jihui; Kim, Hoonmin; Park, Jongho; Yeo, Sunmi; Shim, Hwan; Lim, Hyungjoon; Yoo, Yangmo</p> <p>2014-03-01</p> <p>Atherosclerosis is a leading cause of cardiovascular disease. The early diagnosis of atherosclerosis is of clinical interest since it can prevent any adverse effects of atherosclerotic vascular diseases. In this paper, a new carotid artery radial <span class="hlt">strain</span> estimation method based on autocorrelation is presented. In the proposed method, the <span class="hlt">strain</span> is first estimated by the autocorrelation of two complex signals from the consecutive frames. Then, the angular phase from autocorrelation is converted to <span class="hlt">strain</span> and <span class="hlt">strain</span> rate and they are analyzed over time. In addition, a 2D <span class="hlt">strain</span> image over region of interest in a carotid artery can be displayed. To evaluate the feasibility of the proposed radial <span class="hlt">strain</span> estimation method, radiofrequency (RF) data of 408 frames in the carotid artery of a volunteer were acquired by a commercial ultrasound system equipped with a research package (V10, Samsung Medison, Korea) by using a L5-13IS linear array transducer. From in vivo carotid artery data, the mean <span class="hlt">strain</span> estimate was -0.1372 while its minimum and maximum values were -2.961 and 0.909, respectively. Moreover, the overall <span class="hlt">strain</span> estimates are highly correlated with the reconstructed M-mode trace. Similar results were obtained from the estimation of the <span class="hlt">strain</span> rate change over time. These results indicate that the proposed carotid artery radial <span class="hlt">strain</span> estimation method is useful for assessing the arterial wall's stiffness noninvasively without increasing the computational complexity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol24/pdf/CFR-2014-title40-vol24-sec180-1209.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title40-vol24/pdf/CFR-2014-title40-vol24-sec180-1209.pdf"><span>40 CFR 180.1209 - Bacillus subtilis <span class="hlt">strain</span> QST 713 and <span class="hlt">strain</span> QST 713 variant soil; exemption from the requirement...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... <span class="hlt">strain</span> QST 713 variant soil; exemption from the requirement of a tolerance. 180.1209 Section 180.1209... <span class="hlt">strain</span> QST 713 and <span class="hlt">strain</span> QST 713 variant soil; exemption from the requirement of a tolerance. An... Bacillus subtilis <span class="hlt">strain</span> QST 713 and <span class="hlt">strain</span> QST 713 variant soil when used in or on all food commodities....</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol25/pdf/CFR-2013-title40-vol25-sec180-1209.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title40-vol25/pdf/CFR-2013-title40-vol25-sec180-1209.pdf"><span>40 CFR 180.1209 - Bacillus subtilis <span class="hlt">strain</span> QST 713 and <span class="hlt">strain</span> QST 713 variant soil; exemption from the requirement...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>... <span class="hlt">strain</span> QST 713 variant soil; exemption from the requirement of a tolerance. 180.1209 Section 180.1209... <span class="hlt">strain</span> QST 713 and <span class="hlt">strain</span> QST 713 variant soil; exemption from the requirement of a tolerance. An... Bacillus subtilis <span class="hlt">strain</span> QST 713 and <span class="hlt">strain</span> QST 713 variant soil when used in or on all food commodities....</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25769835','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25769835"><span>Tropical <span class="hlt">strains</span> of Ralstonia solanacearum Outcompete race 3 biovar 2 <span class="hlt">strains</span> at lowland tropical temperatures.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Huerta, Alejandra I; Milling, Annett; Allen, Caitilyn</p> <p>2015-05-15</p> <p>Bacterial wilt, caused by members of the heterogenous Ralstonia solanacearum species complex, is an economically important vascular disease affecting many crops. Human activity has widely disseminated R. solanacearum <span class="hlt">strains</span>, increasing their global agricultural impact. However, tropical highland race 3 biovar 2 (R3bv2) <span class="hlt">strains</span> do not cause disease in tropical lowlands, even though they are virulent at warm temperatures. We tested the hypothesis that differences in temperature adaptation and competitive fitness explain the uneven geographic distribution of R. solanacearum <span class="hlt">strains</span>. Using three phylogenetically and ecologically distinct <span class="hlt">strains</span>, we measured competitive fitness at two temperatures following paired-<span class="hlt">strain</span> inoculations of their shared host, tomato. Lowland tropical <span class="hlt">strain</span> GMI1000 was only weakly virulent on tomato under temperate conditions (24°C for day and 19°C for night [24/19°C]), but highland tropical R3bv2 <span class="hlt">strain</span> UW551 and U.S. warm temperate <span class="hlt">strain</span> K60 were highly virulent at both 24/19°C and 28°C. <span class="hlt">Strain</span> K60 was significantly more competitive than both GMI1000 and UW551 in tomato rhizospheres and stems at 28°C, and GMI1000 also outcompeted UW551 at 28°C. The results were reversed at cooler temperatures, at which highland <span class="hlt">strain</span> UW551 generally outcompeted GMI1000 and K60 in planta. The superior competitive index of UW551 at 24/19°C suggests that adaptation to cool temperatures could explain why only R3bv2 <span class="hlt">strains</span> threaten highland agriculture. <span class="hlt">Strains</span> K60 and GMI1000 each produced different bacteriocins that inhibited growth of UW551 in culture. Such interstrain inhibition could explain why R3bv2 <span class="hlt">strains</span> do not cause disease in tropical lowlands. Copyright © 2015, American Society for Microbiology. All Rights Reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4407210','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4407210"><span>Tropical <span class="hlt">Strains</span> of Ralstonia solanacearum Outcompete Race 3 Biovar 2 <span class="hlt">Strains</span> at Lowland Tropical Temperatures</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Huerta, Alejandra I.; Milling, Annett</p> <p>2015-01-01</p> <p>Bacterial wilt, caused by members of the heterogenous Ralstonia solanacearum species complex, is an economically important vascular disease affecting many crops. Human activity has widely disseminated R. solanacearum <span class="hlt">strains</span>, increasing their global agricultural impact. However, tropical highland race 3 biovar 2 (R3bv2) <span class="hlt">strains</span> do not cause disease in tropical lowlands, even though they are virulent at warm temperatures. We tested the hypothesis that differences in temperature adaptation and competitive fitness explain the uneven geographic distribution of R. solanacearum <span class="hlt">strains</span>. Using three phylogenetically and ecologically distinct <span class="hlt">strains</span>, we measured competitive fitness at two temperatures following paired-<span class="hlt">strain</span> inoculations of their shared host, tomato. Lowland tropical <span class="hlt">strain</span> GMI1000 was only weakly virulent on tomato under temperate conditions (24°C for day and 19°C for night [24/19°C]), but highland tropical R3bv2 <span class="hlt">strain</span> UW551 and U.S. warm temperate <span class="hlt">strain</span> K60 were highly virulent at both 24/19°C and 28°C. <span class="hlt">Strain</span> K60 was significantly more competitive than both GMI1000 and UW551 in tomato rhizospheres and stems at 28°C, and GMI1000 also outcompeted UW551 at 28°C. The results were reversed at cooler temperatures, at which highland <span class="hlt">strain</span> UW551 generally outcompeted GMI1000 and K60 in planta. The superior competitive index of UW551 at 24/19°C suggests that adaptation to cool temperatures could explain why only R3bv2 <span class="hlt">strains</span> threaten highland agriculture. <span class="hlt">Strains</span> K60 and GMI1000 each produced different bacteriocins that inhibited growth of UW551 in culture. Such interstrain inhibition could explain why R3bv2 <span class="hlt">strains</span> do not cause disease in tropical lowlands. PMID:25769835</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19820059659&hterms=Durbin&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DDurbin','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19820059659&hterms=Durbin&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DDurbin"><span>The premixed flame in uniform <span class="hlt">straining</span> flow</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Durbin, P. A.</p> <p>1982-01-01</p> <p>Characteristics of the premixed flame in uniform <span class="hlt">straining</span> flow are investigated by the technique of activation-energy asymptotics. An inverse method is used, which avoids some of the restrictions of previous analyses. It is shown that this method recovers known results for adiabatic flames. New results for flames with heat loss are obtained, and it is shown that, in the presence of finite heat loss, <span class="hlt">straining</span> can extinguish flames. A stability analysis shows that <span class="hlt">straining</span> can suppress the cellular instability of flames with Lewis number less than unity. <span class="hlt">Strain</span> can produce instability of flames with Lewis number greater than unity. A comparison shows quite good agreement between theoretical deductions and experimental observations of Ishizuka, Miyasaka & Law (1981).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1013558','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1013558"><span>Method of transferring <span class="hlt">strained</span> semiconductor structure</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Nastasi, Michael A.; Shao, Lin</p> <p>2009-12-29</p> <p>The transfer of <span class="hlt">strained</span> semiconductor layers from one substrate to another substrate involves depositing a multilayer structure on a substrate having surface contaminants. An interface that includes the contaminants is formed in between the deposited layer and the substrate. Hydrogen atoms are introduced into the structure and allowed to diffuse to the interface. Afterward, the deposited multilayer structure is bonded to a second substrate and is separated away at the interface, which results in transferring a multilayer structure from one substrate to the other substrate. The multilayer structure includes at least one <span class="hlt">strained</span> semiconductor layer and at least one <span class="hlt">strain</span>-induced seed layer. The <span class="hlt">strain</span>-induced seed layer can be optionally etched away after the layer transfer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19870013527','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19870013527"><span>Optical <span class="hlt">strain</span> measurement system development, phase 1</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lant, Christian T.; Qaqish, Walid</p> <p>1987-01-01</p> <p>A laser speckle, differential <span class="hlt">strain</span> measurement system was built and tested for future applications in hostile environments. One dimensional electronic correlation of speckle pattern movement allows a quasi-real time measure of <span class="hlt">strain</span>. The system was used successfully to measure uniaxial <span class="hlt">strain</span> reaching into plastic deformation of a test specimen, at temperatures ranging to 450 C. A resolution of 16 microstrain is given by the photodiode array sensor pitch and the specimen to sensor separation. The <span class="hlt">strain</span> measurement limit of the gauge is determined by air density perturbations causing decorrelation of the reference and shifted speckle patterns, and may be improved by limiting convective flow in the immediate vicinity of the test specimen.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://kidshealth.org/en/parents/broken-bones.html','NIH-MEDLINEPLUS'); return false;" href="https://kidshealth.org/en/parents/broken-bones.html"><span>Broken Bones, Sprains, and <span class="hlt">Strains</span> (For Parents)</span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p>... for TV, Video Games, and the Internet Broken Bones, Sprains, and <span class="hlt">Strains</span> KidsHealth > For Parents > Broken Bones, ... home. What to Do: For a Suspected Broken Bone: Do not move a child whose injury involves ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940008401','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940008401"><span><span class="hlt">Strain</span> sensing technology for high temperature applications</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Williams, W. Dan</p> <p>1993-01-01</p> <p>This review discusses the status of <span class="hlt">strain</span> sensing technology for high temperature applications. Technologies covered are those supported by NASA such as required for applications in hypersonic vehicles and engines, advanced subsonic engines, as well as material and structure development. The applications may be at temperatures of 540 C (1000 F) to temperatures in excess of 1400 C (2500 F). The most promising technologies at present are the resistance <span class="hlt">strain</span> gage and remote sensing schemes. Resistance <span class="hlt">strain</span> gages discussed include the BCL gage, the LaRC compensated gage, and the PdCr gage. Remote sensing schemes such as laser based speckle <span class="hlt">strain</span> measurement, phase-shifling interferometry, and x-ray extensometry are discussed. Present status and limitations of these technologies are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..MARZ39008B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..MARZ39008B"><span>Can a <span class="hlt">strain</span> yield a qubit?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Benjamin, Colin</p> <p>2015-03-01</p> <p>A Josepshon qubit is designed via the application of a tensile <span class="hlt">strain</span> to a topological insulator surface, sandwiched between two s-wave superconductors. The <span class="hlt">strain</span> applied leads to a shift in Dirac point without changing the conducting states existing on the surface of a topological insulator. This <span class="hlt">strain</span> applied can be tuned to form a π-junction in such a structure. Combining two such junctions in a ring architecture leads to the ground state of the ring being in a doubly degenerate state- ``0'' and ``1'' states of the qubit. A qubit designed this way is easily controlled via the tunable <span class="hlt">strain</span>. We report on the conditions necessary to design such a qubit. Finally the operating time of a single qubit phase gate is derived. This work was supported by funds from Dept. of Science and Technology (Nanomission), Govt. of India, Grant No. SR/NM/NS-1101/2011.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25817029','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25817029"><span>Survival and activity of individual bioaugmentation <span class="hlt">strains</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dueholm, Morten S; Marques, Irina G; Karst, Søren M; D'Imperio, Seth; Tale, Vaibhav P; Lewis, Derrick; Nielsen, Per Halkjær; Nielsen, Jeppe Lund</p> <p>2015-06-01</p> <p>Successful application of bioaugmentation for enhanced degradation of environmental pollutants is often limited by the lack of methods to monitor the survival and activity of individual bioaugmentation <span class="hlt">strains</span>. However, recent advancements in sequencing technologies and molecular techniques now allow us to address these limitations. Here a complementing set of general applicable molecular methods are presented that provides detailed information on the performance of individual bioaugmentation <span class="hlt">strains</span> under in situ conditions. The approach involves genome sequencing to establish highly specific qPCR and RT-qPCR tools for cell enumerations and expression of involved genes, stable isotope probing to follow growth on the target compounds and GFP-tagging to visualize the bioaugmentation <span class="hlt">strains</span> directly in samples, all in combination with removal studies of the target compounds. The concept of the approach is demonstrated through a case study involving degradation of aromatic hydrocarbons in activated sludge augmented with the bioaugmentation <span class="hlt">strain</span> Pseudomonas monteilii SB3078.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050163141','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050163141"><span><span class="hlt">Strained</span> Hydrocarbons as Potential Hypergolic Fuels</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2005-01-01</p> <p>A storable combination of high-energy hypergolic fuel and oxidizer is advantageous to the future of reusable launch vehicles (RLVs). The combination will allow an increase in energy per unit volume of fuel and eliminate the need for an external ignition system. <span class="hlt">Strained</span> systems have been studied as potential high-density fuels. Adding hypergolic functional groups, such as amino groups, to these hydrocarbons will potentially allow auto ignition of <span class="hlt">strained</span> systems with hydrogen peroxide. Several straight chain amines and their <span class="hlt">strained</span> counterparts containing an equivalent number of carbon atoms have been purchased and synthesized. These amines provide initial studies to determine the effects of fuel vapor pressure, <span class="hlt">strain</span> energy, fuel miscibility, and amine substitution upon fuel ignition time and hypergolicity with hydrogen peroxide as an oxidizer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27872965','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27872965"><span>Novel Technologies for Optimal <span class="hlt">Strain</span> Breeding.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bott, Michael; Eggeling, Lothar</p> <p></p> <p>The implementation of a knowledge-based bioeconomy requires the rapid development of highly efficient microbial production <span class="hlt">strains</span> that are able to convert renewable carbon sources to value-added products, such as bulk and fine chemicals, pharmaceuticals, or proteins at industrial scale. Starting from classical <span class="hlt">strain</span> breeding by random mutagenesis and screening in the 1950s via rational design by metabolic engineering initiated in the 1970s, a range of powerful new technologies have been developed in the past two decades that can revolutionize future <span class="hlt">strain</span> engineering. In particular, next-generation sequencing technologies combined with new methods of genome engineering and high-throughput screening based on genetically encoded biosensors have allowed for new concepts. In this chapter, selected new technologies relevant for breeding microbial production <span class="hlt">strains</span> with a special emphasis on amino acid producers will be summarized.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SPIE.8346E..1CT','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SPIE.8346E..1CT"><span>Aerosol printed carbon nanotube <span class="hlt">strain</span> sensor</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thompson, Bradley; Yoon, Hwan-Sik</p> <p>2012-04-01</p> <p>In recent years, printed electronics have received attention as a method to produce low-cost macro electronics on flexible substrates. In this regard, inkjet and aerosol printing have been the primary printing methods for producing passive electrical components, transistors, and a number of sensors. In this research, a custom aerosol printer was utilized to create a <span class="hlt">strain</span> sensor capable of measuring static and dynamic <span class="hlt">strain</span>. The proposed sensor was created by aerosol printing a multiwall carbon nanotube solution onto an aluminum beam covered with an insulating layer. After printing the carbon nanotube-based sensor, the sensor was tested under quasi-static and vibration <span class="hlt">strain</span> conditions, and the results are presented. The results show that the printed sensor could potentially serve as an effective method for measuring dynamic <span class="hlt">strain</span> of structural components.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=243113','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=243113"><span>Carotene-superproducing <span class="hlt">strains</span> of Phycomyces.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Murillo, F J; Calderón, I L; López-Díaz, I; Cerdá-Olmedo, E</p> <p>1978-01-01</p> <p>Production of beta-carotene by wild-type Phycomyces blakesleeanus can be stimulated by light, chemicals, regulatory mutations, and sexual interaction between mycelia of opposite sex. Through genetic manipulations, we have isolated <span class="hlt">strains</span> which have simultaneously and constitutively incorporated several of these stimulatory effects. In the dark and in a simple medium, some of the <span class="hlt">strains</span> produce up to 25 mg of beta-carotene per g (dry weight), or about 500 times the wild-type production under the same conditions. High lycopene-producing <span class="hlt">strains</span> have also been isolated by using carR mutants, which are blocked in the conversion of lycopene to beta-carotene. These <span class="hlt">strains</span> should be useful in both industrial production of these pigments and basic research related to carotenogenesis. PMID:727783</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19870019450','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19870019450"><span>Thin film <span class="hlt">strain</span> gage development program</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Grant, H. P.; Przybyszewski, J. S.; Anderson, W. L.; Claing, R. G.</p> <p>1983-01-01</p> <p>Sputtered thin-film dynamic <span class="hlt">strain</span> gages of 2 millimeter (0.08 in) gage length and 10 micrometer (0.0004 in) thickness were fabricated on turbojet engine blades and tested in a simulated compressor environment. Four designs were developed, two for service to 600 K (600 F) and two for service to 900 K (1200 F). The program included a detailed study of guidelines for formulating <span class="hlt">strain</span>-gage alloys to achieve superior dynamic and static gage performance. The tests included gage factor, fatigue, temperature cycling, spin to 100,000 G, and erosion. Since the installations are 30 times thinner than conventional wire <span class="hlt">strain</span> gage installations, and any alteration of the aerodynamic, thermal, or structural performance of the blade is correspondingly reduced, dynamic <span class="hlt">strain</span> measurement accuracy higher than that attained with conventional gages is expected. The low profile and good adherence of the thin film elements is expected to result in improved durability over conventional gage elements in engine tests.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004SPIE.5373..173T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004SPIE.5373..173T"><span>Simultaneous narrowband ultrasonic <span class="hlt">strain</span>-flow imaging</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tsou, Jean K.; Mai, Jerome J.; Lupotti, Fermin A.; Insana, Michael F.</p> <p>2004-04-01</p> <p>We are summarizing new research aimed at forming spatially and temporally registered combinations of <span class="hlt">strain</span> and color-flow images using echo data recorded from a commercial ultrasound system. Applications include diagnosis of vascular diseases and tumor malignancies. The challenge is to meet the diverse needs of each measurement. The approach is to first apply eigenfilters that separate echo components from moving tissues and blood flow, and then estimate blood velocity and tissue displacement from the filtered-IQ-signal phase modulations. At the cost of a lower acquisition frame rate, we find the autocorrelation <span class="hlt">strain</span> estimator yields higher resolution <span class="hlt">strain</span> estimate than the cross-correlator since estimates are made from ensembles at a single point in space. The technique is applied to in vivo carotid imaging, to demonstrate the sensitivity for <span class="hlt">strain</span>-flow vascular imaging.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=strain+AND+gauges&id=EJ095175','ERIC'); return false;" href="http://eric.ed.gov/?q=strain+AND+gauges&id=EJ095175"><span>Dynamic Force Measurement with <span class="hlt">Strain</span> Gauges</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Lee, Bruce E.</p> <p>1974-01-01</p> <p>Discusses the use of four <span class="hlt">strain</span> gauges, a Wheatstone bridge, and an oscilloscope to measure forces dynamically. Included is an example of determining the centripetal force of a pendulum in a general physics laboratory. (CC)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19870006975','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19870006975"><span>Analysis of silicon stress/<span class="hlt">strain</span> relationships</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dillon, O.</p> <p>1986-01-01</p> <p>Results are presented for work on stress-<span class="hlt">strain</span> relationships in silicon ribbon. Calculations of stress fields, dislocation desities, and buckling were made; uniaxial tensile tests were made on silicon at 1150 C; and dislocation motion studies were performed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850024124','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850024124"><span>Silicon ribbon stress-<span class="hlt">strain</span> activities</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wada, B. K.; Shih, C. F.; Kuo, C. P.; Phillips, W. M.</p> <p>1984-01-01</p> <p>The finite element method is used to investigate stress/<span class="hlt">strain</span> in silicon ribbon. Failure considerations such as residual stress, buckling material non-linearity and creep are discussed. Temperature profiles are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=centripetal+AND+force&pg=2&id=EJ095175','ERIC'); return false;" href="https://eric.ed.gov/?q=centripetal+AND+force&pg=2&id=EJ095175"><span>Dynamic Force Measurement with <span class="hlt">Strain</span> Gauges</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Lee, Bruce E.</p> <p>1974-01-01</p> <p>Discusses the use of four <span class="hlt">strain</span> gauges, a Wheatstone bridge, and an oscilloscope to measure forces dynamically. Included is an example of determining the centripetal force of a pendulum in a general physics laboratory. (CC)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1987isa..symp..607D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1987isa..symp..607D"><span>The new international <span class="hlt">strain</span> gage specification</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dorsey, Jim</p> <p></p> <p>Previous standards for the performance tests of metallic resistance <span class="hlt">strain</span> gages and the shortcomings of these old standards are discussed together with the new standards recommended by the Organisation Internationale de Metrologie Legale (OIML) as described in the International Recommendation No. 62 'Performance Characteristics of Metallic Resistance <span class="hlt">Strain</span> Gauges'. The OIML Recommendation No. 62 was adopted in 1984 as an international <span class="hlt">strain</span> gage standard. It will allow all nations to select their own test methods, but requires each nation to accept the methods and equipment of others. The Recommendation No. 62 includes sections on terminology, test requirements, data reduction and statistics, and the presentation of data. When the United States completes a revision to ASTM E-251, all of the tools will be available for the U.S. manufacturers of <span class="hlt">strain</span> gages to comply with the requirements of most industrialized countries of the world.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ApPhL.107s3102G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ApPhL.107s3102G"><span>Tuning <span class="hlt">strain</span> in flexible graphene nanoelectromechanical resonators</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guan, Fen; Kumaravadivel, Piranavan; Averin, Dmitri V.; Du, Xu</p> <p>2015-11-01</p> <p>The structural flexibility of low dimensional nanomaterials offers unique opportunities for studying the impact of <span class="hlt">strain</span> on their physical properties and for developing innovative devices utilizing <span class="hlt">strain</span> engineering. A key towards such goals is a device platform which allows the independent tuning and reliable calibration of the <span class="hlt">strain</span>. Here, we report the fabrication and characterization of graphene nanoelectromechanical resonators (GNEMRs) on flexible substrates. Combining substrate bending and electrostatic gating, we achieve the independent tuning of the <span class="hlt">strain</span> and sagging in graphene and explore the nonlinear dynamics over a wide parameter space. Analytical and numerical studies of a continuum mechanics model, including the competing higher order nonlinear terms, reveal a comprehensive nonlinear dynamics phase diagram, which quantitatively explains the complex behaviors of GNEMRs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70022316','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70022316"><span><span class="hlt">Strain</span> accumulation along the Cascadia subduction zone</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Murray, M.H.; Lisowski, M.</p> <p>2000-01-01</p> <p>We combine triangulation, trilateration, and GPS observations to determine horizontal <span class="hlt">strain</span> rates along the Cascadia subduction zone from Cape Mendocino to the Strait of Juan de Fuca. Shear-<span class="hlt">strain</span> rates are significantly greater than zero (95% confidence) in all forearc regions (26-167 nanoradians/yr), and are not significant in the arc and backarc regions. The deformation is primarily uniaxial contraction nearly parallel to Juan de Fuca-North America plate convergence (N55??-80??E). The <span class="hlt">strain</span> rates are consistent with an elastic dislocation model for interseismic slip with a shallow 100-km wide locked zone and a deeper 75-km transition zone along the entire megathrust, except along the central Oregon coast where relatively lower <span class="hlt">strain</span> rates are consistent with 30-40 km wide locked and transition zones.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013NaPho...7...86L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013NaPho...7...86L"><span>Optical physics: Magnetic appeal in <span class="hlt">strained</span> lattice</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lepetit, Thomas</p> <p>2013-02-01</p> <p>Using <span class="hlt">strain</span> to induce a pseudomagnetic field in a photonic lattice at optical frequencies might bring improvements to fields such as photonic crystal fibres, supercontinuum generation and frequency combs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21882791','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21882791"><span>Heat <span class="hlt">strain</span> during explosive ordnance disposal.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stewart, Ian B; Rojek, Amanda M; Hunt, Andrew P</p> <p>2011-08-01</p> <p>Bomb technicians perform their work while encapsulated in explosive ordnance disposal suits. Designed primarily for safety, these suits have an unintended consequence of impairing the body's natural mechanisms for heat dissipation. Consequently, bomb technicians are known to experience symptoms of heat illness while performing their work. This research provides the first field based analysis of heat <span class="hlt">strain</span> in bomb technicians. Six participants undertook simulated operational tasks across 2 days of variable climate. All subjects demonstrated high levels of heat <span class="hlt">strain</span> as evidenced by elevated heart rate, core body temperature, and physiological <span class="hlt">strain</span> index. Participants also reported signs and symptoms associated with heat illness. These results were exacerbated by more intense physical activity despite being undertaken in a cooler environment. The universal experience of heat <span class="hlt">strain</span> in this sample has significant implications for the health of bomb technicians and additional research examining methods to improve temperature regulation and performance is warranted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930081520','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930081520"><span>The Development of Electrical <span class="hlt">Strain</span> Gages</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>De Forest, A V; Leaderman, H</p> <p>1940-01-01</p> <p>The design, construction, and properties of an electrical-resistance <span class="hlt">strain</span> gage consisting of fine wires molded in a laminated plastic are described. The properties of such gages are discussed and also the problems of molding of wires in plastic materials, temperature compensation, and cementing and removal of the gages. Further work to be carried out on the <span class="hlt">strain</span> gage, together with instrument problems, is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870000237&hterms=uses+pulley&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Duses%2Bpulley','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870000237&hterms=uses+pulley&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Duses%2Bpulley"><span>Hydraulic Calibrator for <span class="hlt">Strain</span>-Gauge Balances</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Skelly, Kenneth; Ballard, John</p> <p>1987-01-01</p> <p>Instrument for calibrating <span class="hlt">strain</span>-gauge balances uses hydraulic actuators and load cells. Eliminates effects of nonparallelism, nonperpendicularity, and changes of cable directions upon vector sums of applied forces. Errors due to cable stretching, pulley friction, and weight inaccuracy also eliminated. New instrument rugged and transportable. Set up quickly. Developed to apply known loads to wind-tunnel models with encapsulated <span class="hlt">strain</span>-gauge balances, also adapted for use in calibrating dynamometers, load sensors on machinery and laboratory instruments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20050179347&hterms=Adhesives&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DAdhesives','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20050179347&hterms=Adhesives&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DAdhesives"><span>High-Temperature Adhesive <span class="hlt">Strain</span> Gage Developed</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pereira, J. Michael; Roberts, Gary D.</p> <p>1997-01-01</p> <p>Researchers at the NASA Lewis Research Center have developed a unique <span class="hlt">strain</span> gage and adhesive system for measuring the mechanical properties of polymers and polymer composites at elevated temperatures. This system overcomes some of the problems encountered in using commercial <span class="hlt">strain</span> gages and adhesives. For example, typical commercial <span class="hlt">strain</span> gage adhesives require a postcure at temperatures substantially higher than the maximum test temperature. The exposure of the specimen to this temperature may affect subsequent results, and in some cases may be higher than the glass-transition temperature of the polymer. In addition, although typical commercial <span class="hlt">strain</span> gages can be used for short times at temperatures up to 370 C, their long-term use is limited to 230 C. This precludes their use for testing some high-temperature polyimides near their maximum temperature capability. Lewis' <span class="hlt">strain</span> gage and adhesive system consists of a nonencapsulated, unbacked gage grid that is bonded directly to the polymer after the specimen has been cured but prior to the normal postcure cycle. The gage is applied with an adhesive specially formulated to cure under the specimen postcure conditions. Special handling, mounting, and electrical connection procedures were developed, and a fixture was designed to calibrate each <span class="hlt">strain</span> gage after it was applied to a specimen. A variety of tests was conducted to determine the performance characteristics of the gages at elevated temperatures on PMR-15 neat resin and titanium specimens. For these tests, which included static tension, thermal exposure, and creep tests, the gage and adhesive system performed within normal <span class="hlt">strain</span> gage specifications at 315 C. An example of the performance characteristics of the gage can be seen in the figure, which compares the <span class="hlt">strain</span> gage measurement on a polyimide specimen at 315 C with an extensometer measurement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SPIE.8671E..1EP','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SPIE.8671E..1EP"><span>Geometric reconstruction using tracked ultrasound <span class="hlt">strain</span> imaging</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pheiffer, Thomas S.; Simpson, Amber L.; Ondrake, Janet E.; Miga, Michael I.</p> <p>2013-03-01</p> <p>The accurate identification of tumor margins during neurosurgery is a primary concern for the surgeon in order to maximize resection of malignant tissue while preserving normal function. The use of preoperative imaging for guidance is standard of care, but tumor margins are not always clear even when contrast agents are used, and so margins are often determined intraoperatively by visual and tactile feedback. Ultrasound <span class="hlt">strain</span> imaging creates a quantitative representation of tissue stiffness which can be used in real-time. The information offered by <span class="hlt">strain</span> imaging can be placed within a conventional image-guidance workflow by tracking the ultrasound probe and calibrating the image plane, which facilitates interpretation of the data by placing it within a common coordinate space with preoperative imaging. Tumor geometry in <span class="hlt">strain</span> imaging is then directly comparable to the geometry in preoperative imaging. This paper presents a tracked ultrasound <span class="hlt">strain</span> imaging system capable of co-registering with preoperative tomograms and also of reconstructing a 3D surface using the border of the <span class="hlt">strain</span> lesion. In a preliminary study using four phantoms with subsurface tumors, tracked <span class="hlt">strain</span> imaging was registered to preoperative image volumes and then tumor surfaces were reconstructed using contours extracted from <span class="hlt">strain</span> image slices. The volumes of the phantom tumors reconstructed from tracked <span class="hlt">strain</span> imaging were approximately between 1.5 to 2.4 cm3, which was similar to the CT volumes of 1.0 to 2.3 cm3. Future work will be done to robustly characterize the reconstruction accuracy of the system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3647418','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3647418"><span>Feline Origin of Rotavirus <span class="hlt">Strain</span>, Tunisia, 2008</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Fredj, Mouna Ben Hadj; Heylen, Elisabeth; Zeller, Mark; Fodha, Imene; Benhamida-Rebai, Meriam; Van Ranst, Marc; Matthijnssens, Jelle</p> <p>2013-01-01</p> <p>In Tunisia in 2008, an unusual G6P[9] rotavirus, RVA/human-wt/TUN/17237/2008/G6P[9], rarely found in humans, was detected in a child. To determine the origin of this <span class="hlt">strain</span>, we conducted phylogenetic analyses and found a unique genotype constellation resembling rotaviruses belonging to the feline BA222-like genotype constellation. The <span class="hlt">strain</span> probably resulted from direct cat-to-human transmission. PMID:23631866</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MMTA...48.3175G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MMTA...48.3175G"><span>Prediction of Transformation <span class="hlt">Strain</span> Using Microtexture Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Giri, Sushil K.; Biswas, Pinaki; Kundu, Saurabh</p> <p>2017-07-01</p> <p>The transformation <span class="hlt">strain</span>, resulting from austenite-to-bainite transformation induced under both external stress and without stress, is estimated by employing two different mathematical models. These models use actual fractions of individual variants in every prior austenite grain, which are calculated using electron backscattered diffraction (EBSD) scans after reconstruction of prior austenite microstructure. The <span class="hlt">strains</span> predicted by models match closely with the experimentally determined macrostrain obtained using dilation data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JNS....23..113W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JNS....23..113W"><span>Superinfection Behaviors on Scale-Free Networks with Competing <span class="hlt">Strains</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Qingchu; Small, Michael; Liu, Huaxiang</p> <p>2013-02-01</p> <p>This paper considers the epidemiology of two <span class="hlt">strains</span> ( I, J) of a disease spreading through a population represented by a scale-free network. The epidemiological model is SIS and the two <span class="hlt">strains</span> have different reproductive numbers. Superinfection means that <span class="hlt">strain</span> I can infect individuals already infected with <span class="hlt">strain</span> J, replacing the <span class="hlt">strain</span> J infection. Individuals infected with <span class="hlt">strain</span> I cannot be infected with <span class="hlt">strain</span> J. The model is set up as a system of ordering differential equations and stability of the disease free, marginal <span class="hlt">strain</span> I and <span class="hlt">strain</span> J, and coexistence equilibria are assessed using linear stability analysis, supported by simulations. The main conclusion is that superinfection, as modeled in this paper, can allow <span class="hlt">strain</span> I to coexist with <span class="hlt">strain</span> J even when it has a lower basic reproductive number. Most strikingly, it can allow <span class="hlt">strain</span> I to persist even when its reproductive number is less than 1.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6722711','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6722711"><span>Fermentation studies using Saccharomyces diastaticus yeast <span class="hlt">strains</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Erratt, J.A.; Stewart, G.G.</p> <p>1981-01-01</p> <p>The yeast species, Saccharomyces diastaticus, has the ability to ferment starch and dextrin, because of the extracellular enzyme, glucoamylase, which hydrolyzes the starch/dextrin to glucose. A number of nonallelic genes--DEX 1, DEX 2, and dextrinase B which is allelic to STA 3--have been isolated, which impart to the yeast the ability to ferment dextrin. Various diploid yeast <span class="hlt">strains</span> were constructed, each being either heterozygous or homozygous for the individual dextrinase genes. Using 12 (sup 0) plato hopped wort (30% corn adjunct) under agitated conditions, the fermentation rates of the various diploid yeast <span class="hlt">strains</span> were monitored. A gene-dosage effect was exhibited by yeast <span class="hlt">strains</span> containing DEX 1 or DEX 2, however, not with yeast <span class="hlt">strains</span> containing dextrinase B (STA 3). The fermentation and growth rates and extents were determined under static conditions at 14.4 C and 21 C. With all yeast <span class="hlt">strains</span> containing the dextrinase genes, both fermentation and growth were increased at the higher incubation temperature. Using 30-liter fermentors, beer was produced with the various yeast <span class="hlt">strains</span> containing the dextrinase genes and the physical and organoleptic characteristics of the products were determined. The concentration of glucose in the beer was found to increase during a 3-mo storage period at 21 C, indicating that the glucoamylase from Saccharomyces diastaticus is not inactivated by pasteurization. (Refs. 36).</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011OptMa..33..408F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011OptMa..33..408F"><span>Flexible photonic crystals for <span class="hlt">strain</span> sensing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fortes, Luís M.; Gonçalves, M. Clara; Almeida, Rui M.</p> <p>2011-01-01</p> <p>Three-dimensional (3-D) photonic crystals (PCs) have been studied as possible <span class="hlt">strain</span> sensing materials, based on <span class="hlt">strain</span>-induced stop band frequency shifting. Self-assembly of polystyrene microspheres, achieved by sedimentation over a flexible polyimide tape substrate whose surface hydrophilicity was optimized in order to achieve maximum wettability, led to an organized 3-D direct opal template. This was infiltrated with a silica sol-gel solution by dip-coating or by chemical vapour deposition and an inverse opal structure was ultimately obtained by chemical dissolution of the polymer template. The structural and optical properties of these PCs have been studied by scanning electron microscopy (FE-SEM) and UV/visible spectroscopy under variable degrees of <span class="hlt">strain</span>. FE-SEM showed the presence of ordered domains up to ∼30 μm2. A mechano-optical effect was evidenced by <span class="hlt">strain</span>-induced shifting of the photonic stop band peak wavelength of the direct, infiltrated and inverse opals up to 50 nm in transmission mode, due to changes in interplanar spacing upon bending the flexible PCs. Optical response <span class="hlt">strain</span> cycles were studied, suggesting the possible use of these structures in reversible photonic <span class="hlt">strain</span> sensors integrated in sensor/actuator devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/10161061','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/10161061"><span>Thermographic phosphor <span class="hlt">strain</span> measurements. Final report</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Allison, S.W.; Capps, G.J.; Smith, D.B.; Cates, M.R.; Gleason, J.; Turley, W.D.</p> <p>1994-05-01</p> <p>This report describes the first phase of research aimed at developing a high-temperature <span class="hlt">strain</span> gauge for power equipment use based on materials whose fluorescence characteristics are affected by <span class="hlt">strain</span>. In electric power generating plants, the combined effect of temperature and <span class="hlt">strain</span> on equipment and structures is a critical factor in safe, efficient operation and component lifetime. For the first part of this project, the pressure responses of phosphor and crystalline materials were surveyed. Next, pressure measurements on some promising materials, YVO{sub 4}:Dy and Gd{sub 2}O{sub 2}S:Tb, were performed. The latter phosphor appears to exhibit the greatest change with pressure. Its fluorescence lifetime decreases by a factor of 10 with pressure increase of 20 kbar. In a <span class="hlt">strain</span> test configuration, a tapered sapphire rod compressed a similar phosphor material, La{sub 2}O{sub 2}S:Eu. The intensity level increased, as expected for this material, with compression. Both of the oxysulfide materials possess potential for use in an optical <span class="hlt">strain</span> gauge for temperatures up to at least 300{degrees}C. It is suggested that a mixture of these two materials may be a useful way to obtain the maximum pressure or <span class="hlt">strain</span> sensitivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.H43E1060P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.H43E1060P"><span>Colloid <span class="hlt">Straining</span> within Saturated Heterogeneous Porous Media</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Porubcan, A.; Walczak, J.; Xu, S.</p> <p>2008-12-01</p> <p>A thorough understanding of colloid movement in the subsurface system is critical to the assessment of groundwater pollution by pathogenic bacteria and colloid-bound contaminants. It is increasingly recognized that <span class="hlt">straining</span>, a process that occurs when the pore space is too small to allow for a particle's passage, represents an important process in colloid immobilization within groundwater systems. Previously published studies have focused on the kinetics of colloid <span class="hlt">straining</span> within sand packs composed of uniform mineral grains. Natural aquifers, however, are usually characterized by physically heterogeneous sediments. In this study, we conducted column transport experiments with carboxylated latex particles and quartz sand to investigate the impact of sediment texture (i.e., the size distribution of mineral grains) on colloid <span class="hlt">straining</span> kinetics. The quartz sands used in the experiment were thoroughly cleaned and the strong repulsive interactions between colloid particles and quartz sands resulted in minimal physicochemical deposition so the <span class="hlt">straining</span> kinetics can be quantified unambiguously. Sand packs of different textures were prepared by mixing sands of various sizes (mesh sizes of 20-25, 35-40 and 60-70). Our results suggested that the ratio of colloid size and the median sand grain size was insufficient to predict colloid <span class="hlt">straining</span> within heterogeneous sediments. Soil texture, which was related to the size distribution of the sand grains, must be considered. A relationship between colloid <span class="hlt">straining</span> kinetics and the heterogeneity of porous media that can be useful for the prediction of colloid transport within heterogeneous sediments was presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/902633','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/902633"><span>Load cell having <span class="hlt">strain</span> gauges of arbitrary location</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Spletzer, Barry</p> <p>2007-03-13</p> <p>A load cell utilizes a plurality of <span class="hlt">strain</span> gauges mounted upon the load cell body such that there are six independent load-<span class="hlt">strain</span> relations. Load is determined by applying the inverse of a load-<span class="hlt">strain</span> sensitivity matrix to a measured <span class="hlt">strain</span> vector. The sensitivity matrix is determined by performing a multivariate regression technique on a set of known loads correlated to the resulting <span class="hlt">strains</span>. Temperature compensation is achieved by configuring the <span class="hlt">strain</span> gauges as co-located orthogonal pairs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910067307&hterms=1500&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2526%25231500','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910067307&hterms=1500&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2526%25231500"><span>A resistance <span class="hlt">strain</span> gage with repeatable and cancellable apparent <span class="hlt">strain</span> for use to 1500 F</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lei, Jih-Fen</p> <p>1990-01-01</p> <p>A temperature compensated static <span class="hlt">strain</span> gauge, which is fabricated from Pd13Cr alloy and a Pt compensator, is being developed and has been tested over a temperature range to 1500 F at NASA-Lewis. The PdCr compensated <span class="hlt">strain</span> gage has significantly lower apparent <span class="hlt">strain</span> to 500 F than other high temperature <span class="hlt">strain</span> gages. The PdCr compensated gage is protected from oxidation by a flame-sprayed alumina-4 wt pct zirconia overcoating. Test Results to 1500 F indicate apparent <span class="hlt">strain</span> variations of less than 250 micro-epsilon and reproducibility between thermal cycles within 50 micro-epsilon. The apparent <span class="hlt">strain</span> of the coated PdCr compensated gage can be predicted and cancelled due to its reproducibility and low value.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18689636','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18689636"><span>Pathogenesis of XJ and Romero <span class="hlt">strains</span> of Junin virus in two <span class="hlt">strains</span> of guinea pigs.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yun, Nadezhda E; Linde, Nathaniel S; Dziuba, Natallia; Zacks, Michele A; Smith, Jeanon N; Smith, Jennifer K; Aronson, Judy F; Chumakova, Olga V; Lander, Heather M; Peters, Clarence J; Paessler, Slobodan</p> <p>2008-08-01</p> <p>Argentine hemorrhagic fever (AHF), a systemic infectious disease caused by infection with Junin virus, affects several organs, and patients can show hematologic, cardiovascular, renal, or neurologic symptoms. We compared the virulence of two Junin virus <span class="hlt">strains</span> in inbred and outbred guinea pigs with the aim of characterizing this animal model better for future vaccine/antiviral efficacy studies. Our data indicate that this passage of the XJ <span class="hlt">strain</span> is attenuated in guinea pigs. In contrast, the Romero <span class="hlt">strain</span> is highly virulent in <span class="hlt">Strain</span> 13 as well as in Hartley guinea pigs, resulting in systemic infection, thrombocytopenia, elevated aspartate aminotransferase levels, and ultimately, uniformly lethal disease. We detected viral antigen in formalin-fixed, paraffin-embedded tissues. Thus, both guinea pig <span class="hlt">strains</span> are useful animal models for lethal Junin virus (Romero <span class="hlt">strain</span>) infection and potentially can be used for preclinical trials in vaccine or antiviral drug development.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900016747','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900016747"><span>A resistance <span class="hlt">strain</span> gage with repeatable and cancellable apparent <span class="hlt">strain</span> for use to 800 C</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lei, Jih-Fen</p> <p>1990-01-01</p> <p>A temperature compensated static <span class="hlt">strain</span> gage, which is fabricated from palladium-13w/o chromium (Pd13Cr) alloy and a platinum (Pt) compensator, is being developed and was tested over a temperature range to 800 C at NASA-Lewis. The PdCr compensated <span class="hlt">strain</span> gage has significantly lower apparent <span class="hlt">strain</span> to 800 C than other high temperature <span class="hlt">strain</span> gages. The PdCr compensated gage is protected from oxidation by a flame-sprayed alumina-4w/o zirconia overcoating. Test results to 800 C indicate apparent <span class="hlt">strain</span> variations of less than 300 micro-epsilon and reproducibility between thermal cycles within 50 micro-epsilon. Apparent <span class="hlt">strain</span> of the coated PdCr compensated gage can be predicted and cancelled due to its reproducibility and low value.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2700623','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2700623"><span>Pathogenesis of XJ and Romero <span class="hlt">Strains</span> of Junin Virus in Two <span class="hlt">Strains</span> of Guinea Pigs</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yun, Nadezhda E.; Linde, Nathaniel S.; Dziuba, Natallia; Zacks, Michele A.; Smith, Jeanon N.; Smith, Jennifer K.; Aronson, Judy F.; Chumakova, Olga V.; Lander, Heather M.; Peters, Clarence J.; Paessler, Slobodan</p> <p>2008-01-01</p> <p>Argentine hemorrhagic fever (AHF), a systemic infectious disease caused by infection with Junin virus, affects several organs, and patients can show hematologic, cardiovascular, renal, or neurologic symptoms. We compared the virulence of two Junin virus <span class="hlt">strains</span> in inbred and outbred guinea pigs with the aim of characterizing this animal model better for future vaccine/antiviral efficacy studies. Our data indicate that this passage of the XJ <span class="hlt">strain</span> is attenuated in guinea pigs. In contrast, the Romero <span class="hlt">strain</span> is highly virulent in <span class="hlt">Strain</span> 13 as well as in Hartley guinea pigs, resulting in systemic infection, thrombocytopenia, elevated apartate aminotransferase levels, and ultimately, uniformly lethal disease. We detected viral antigen in formalin-fixed, paraffin-embedded tissues. Thus, both guinea pig <span class="hlt">strains</span> are useful animal models for lethal Junin virus (Romero <span class="hlt">strain</span>) infection and potentially can be used for preclinical trials in vaccine or antiviral drug development. PMID:18689636</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1990SPIE.1170..452H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1990SPIE.1170..452H"><span><span class="hlt">Strain</span> or stress component separation in surface mounted interferometric optical fiber <span class="hlt">strain</span> sensors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Haslach, Henry W., Jr.; Sirkis, James S.</p> <p>1990-02-01</p> <p>Design flexibility is often touted as an advantage of optical fiber transducers. This advantage is exploited by formalizing the geometric design of interferometric optical fiber stress and <span class="hlt">strain</span> sensors. The equations that govern the phase-<span class="hlt">strain</span> correlation are used to define some basic design laws. The most common design goal is to separate <span class="hlt">strain</span> or stress components from composite phase-<span class="hlt">strain</span> data. This can be accomplished in a Mach-Zehnder format or in a format in which both the sensing and reference fibers are exposed to the <span class="hlt">strain</span> field. The design laws together with simple configurations are used to devise several fiber transducers. Design flexibility exists because there are many solutions which satisfy the design objectives and constraints. The constant <span class="hlt">strain</span> assumption is the basic of design. A comparison of the transverse sensitivity of resistance and optical fiber gages is presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25582323','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25582323"><span>Purification of Helicobacter suis <span class="hlt">Strains</span> From Biphasic Cultures by Single Colony Isolation: Influence on <span class="hlt">Strain</span> Characteristics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liang, Jungang; De Bruyne, Ellen; Ducatelle, Richard; Smet, Annemieke; Haesebrouck, Freddy; Flahou, Bram</p> <p>2015-06-01</p> <p>Helicobacter (H.) suis causes gastritis and decreased weight gain in pigs. It is also the most prevalent non-Helicobacter pylori Helicobacter species in humans with gastric disease. H. suis is extremely fastidious, and so far, biphasic culture conditions were essential for isolation and culture, making it impossible to obtain single colonies. Hence, cultures obtained from an individual animal may contain multiple H. suis <span class="hlt">strains</span>, which is undesirable for experiments aiming for instance at investigating H. suis <span class="hlt">strain</span> differences. Pure cultures of H. suis were established by growing bacteria as colonies on 1% brucella agar plates, followed by purification and enrichment by biphasic subculture. Characteristics of these single colony-derived <span class="hlt">strains</span> were compared with those of their parent <span class="hlt">strains</span> using multilocus sequence typing (MLST) and by studying bacterium-host interactions using a gastric epithelial cell line and Mongolian gerbil model. The purification/enrichment procedure required a nonstop culture of several weeks. For 4 of 17 H. suis <span class="hlt">strains</span>, MLST revealed differences between parental and single colony-derived <span class="hlt">strains</span>. For three of four single colony-derived <span class="hlt">strains</span> tested, the cell death-inducing capacity was higher than for the parental <span class="hlt">strain</span>. One single colony-derived <span class="hlt">strain</span> lost its capacity to colonize Mongolian gerbils. For the four other <span class="hlt">strains</span> tested, colonization capacity and histopathologic changes were similar to what has been described when using <span class="hlt">strains</span> with only a history of limited biphasic culture. A method was developed to obtain single colony-derived H. suis <span class="hlt">strains</span>, but this procedure may affect the bacterial genotype and phenotype. © 2015 John Wiley & Sons Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22021041','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22021041"><span>Molecular typing of Brucella melitensis endemic <span class="hlt">strains</span> and differentiation from the vaccine <span class="hlt">strain</span> Rev-1.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Noutsios, Georgios T; Papi, Rigini M; Ekateriniadou, Loukia V; Minas, Anastasios; Kyriakidis, Dimitrios A</p> <p>2012-03-01</p> <p>In the present study forty-four Greek endemic <span class="hlt">strains</span> of Br. melitensis and three reference <span class="hlt">strains</span> were genotyped by Multi locus Variable Number Tandem Repeat (ML-VNTR) analysis based on an eight-base pair tandem repeat sequence that was revealed in eight loci of Br. melitensis genome. The forty-four <span class="hlt">strains</span> were discriminated from the vaccine <span class="hlt">strain</span> Rev-1 by Restriction Fragment Length Polymorphism (RFLP) and Denaturant Gradient Gel Electrophoresis (DGGE). The ML-VNTR analysis revealed that endemic, reference and vaccine <span class="hlt">strains</span> are genetically closely related, while most of the loci tested (1, 2, 4, 5 and 7) are highly polymorphic with Hunter-Gaston Genetic Diversity Index (HGDI) values in the range of 0.939 to 0.775. Analysis of ML-VNTRs loci stability through in vitro passages proved that loci 1 and 5 are non stable. Therefore, vaccine <span class="hlt">strain</span> can be discriminated from endemic <span class="hlt">strains</span> by allele's clusters of loci 2, 4, 6 and 7. RFLP and DGGE were also employed to analyse omp2 gene and reveled different patterns among Rev-1 and endemic <span class="hlt">strains</span>. In RFLP, Rev-1 revealed three fragments (282, 238 and 44 bp), while endemic <span class="hlt">strains</span> two fragments (238 and 44 bp). As for DGGE, the electrophoretic mobility of Rev-1 is different from the endemic <span class="hlt">strains</span> due to heterologous binding of DNA chains of omp2a and omp2b gene. Overall, our data show clearly that it is feasible to genotype endemic <span class="hlt">strains</span> of Br. melitensis and differentiate them from vaccine <span class="hlt">strain</span> Rev-1 with ML-VNTR, RFLP and DGGE techniques. These tools can be used for conventional investigations in brucellosis outbreaks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25542202','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25542202"><span>Intramyocardial <span class="hlt">strain</span> estimation from cardiac cine MRI.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Elnakib, Ahmed; Beache, Garth M; Gimel'farb, Georgy; El-Baz, Ayman</p> <p>2015-08-01</p> <p>Functional <span class="hlt">strain</span> is one of the important clinical indicators for the quantification of heart performance and the early detection of cardiovascular diseases, and functional <span class="hlt">strain</span> parameters are used to aid therapeutic decisions and follow-up evaluations after cardiac surgery. A comprehensive framework for deriving functional <span class="hlt">strain</span> parameters at the endocardium, epicardium, and mid-wall of the left ventricle (LV) from conventional cine MRI data was developed and tested. Cine data were collected using short TR-/TE-balanced steady-state free precession acquisitions on a 1.5T Siemens Espree scanner. The LV wall borders are segmented using a level set-based deformable model guided by a stochastic force derived from a second-order Markov-Gibbs random field model that accounts for the object shape and appearance features. Then, the mid-wall of the segmented LV is determined based on estimating the centerline between the endocardium and epicardium of the LV. Finally, a geometrical Laplace-based method is proposed to track corresponding points on successive myocardial contours throughout the cardiac cycle in order to characterize the <span class="hlt">strain</span> evolutions. The method was tested using simulated phantom images with predefined point locations of the LV wall throughout the cardiac cycle. The method was tested on 30 in vivo datasets to evaluate the feasibility of the proposed framework to index functional <span class="hlt">strain</span> parameters. The cine MRI-based model agreed with the ground truth for functional metrics to within 0.30 % for indexing the peak systolic <span class="hlt">strain</span> change and 0.29 % (per unit time) for indexing systolic and diastolic <span class="hlt">strain</span> rates. The method was feasible for in vivo extraction of functional <span class="hlt">strain</span> parameters. <span class="hlt">Strain</span> indexes of the endocardium, mid-wall, and epicardium can be derived from routine cine images using automated techniques, thereby improving the utility of cine MRI data for characterization of myocardial function. Unlike traditional texture-based tracking, the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/762874','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/762874"><span>Imploding Liner Material Strength Measurements at High-<span class="hlt">Strain</span> and High <span class="hlt">Strain</span> Rate</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bartsch, R.R.; Lee, H.; Holtkamp, D.; Wright, B.; Stokes, J.; Morgan, D.; Anderson, W.; Broste, W.</p> <p>1998-10-18</p> <p>Imploding, cylindrical liners provide a unique, shockless means of simultaneously accessing high <span class="hlt">strain</span> and high-<span class="hlt">strain</span>-rate for measurement of strength of materials in plastic flow. The radial convergence in the liner geometry results in the liner thickening as the circumference becomes smaller. <span class="hlt">Strains</span> of up to {approximately}1.25 and <span class="hlt">strain</span> rates of up to {approximately}10{sup 6} sec{sup -1} can be readily achieved in a material sample placed inside of an aluminum driver liner, using the Pegasus II capacitor bank. This provides yield strength data at conditions where none presently exists. The heating from work done against the yield strength is measured with multichannel pyrometry from infrared radiation emitted by the material sample. The temperature data as a function of liner position are unfolded to give the yield strength along the <span class="hlt">strain</span>, <span class="hlt">strain</span>-rate trajectory. Proper design of the liner and sample configuration ensures that the current diffused into the sample adds negligible heating. An important issue, in this type of temperature measurement, is shielding of the pickup optics from other sources of radiation. At <span class="hlt">strains</span> greater than those achievable on Pegasus, e.g. the LANL Atlas facility, some materials may be heated all the way to melt by this process. Recent data on 6061-T6 Aluminum will be compared with an existing model for <span class="hlt">strain</span> and <span class="hlt">strain</span>-rate heating. The liner configuration and pyrometry diagnostic will also be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850013288','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850013288"><span>Thin film <span class="hlt">strain</span> transducer. [suitable for in-flight measurement of scientific balloon <span class="hlt">strain</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rand, J. L. (Inventor)</p> <p>1985-01-01</p> <p>A <span class="hlt">strain</span> transducer system and process for making same is disclosed wherein a beryllium-copper ring having four <span class="hlt">strain</span> gages disposed thereon is electrically connected in Wheatstone bridge fashion to output instrumentation. Tabs are bonded to a balloon or like surface with <span class="hlt">strain</span> on the surface causing bending of the ring and providing an electrical signal through the gages proportional to the surface <span class="hlt">strain</span>. A figure is provided which illustrates a pattern of a one-half ring segment as placed on a sheet of beryllium-copper for chem-mill etch formation, prior to bending and welding of a pair of the segments to form a ring structure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2936195','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2936195"><span>Gradients of <span class="hlt">strain</span> and <span class="hlt">strain</span> rate in the hollow muscular organs of soft-bodied animals</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Thompson, Joseph T.; Taylor, Kari R.; Gentile, Christopher</p> <p>2010-01-01</p> <p>The cylindrical shape of soft-bodied invertebrates is well suited to functions in skeletal support and locomotion, but may result in a previously unrecognized cost—large non-uniformities in muscle <span class="hlt">strain</span> and <span class="hlt">strain</span> rate among the circular muscle fibres of the body wall. We investigated such gradients of <span class="hlt">strain</span> and <span class="hlt">strain</span> rate in the mantle of eight long-finned squid Doryteuthis pealeii and two oval squid Sepioteuthis lessoniana. Transmural gradients of circumferential <span class="hlt">strain</span> were present during all jets (n = 312); i.e. for a given change in the circumference of the outer surface of the mantle, the inner surface experienced a greater proportional change. The magnitude of the difference increased with the amplitude of the mantle movement, with circular muscle fibres at the inner surface of the mantle experiencing a total range of <span class="hlt">strains</span> up to 1.45 times greater than fibres at the outer surface during vigorous jets. Differences in <span class="hlt">strain</span> rate between the circular fibres near the inner versus the outer surface of the mantle were also present in all jets, with the greatest differences occurring during vigorous jetting. The transmural gradients of circumferential <span class="hlt">strain</span> and <span class="hlt">strain</span> rate we describe probably apply not only to squids and other coleoid cephalopods, but also to diverse soft-bodied invertebrates with hollow cylindrical or conical bodies and muscular organs. PMID:20106857</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20106857','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20106857"><span>Gradients of <span class="hlt">strain</span> and <span class="hlt">strain</span> rate in the hollow muscular organs of soft-bodied animals.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Thompson, Joseph T; Taylor, Kari R; Gentile, Christopher</p> <p>2010-08-23</p> <p>The cylindrical shape of soft-bodied invertebrates is well suited to functions in skeletal support and locomotion, but may result in a previously unrecognized cost-large non-uniformities in muscle <span class="hlt">strain</span> and <span class="hlt">strain</span> rate among the circular muscle fibres of the body wall. We investigated such gradients of <span class="hlt">strain</span> and <span class="hlt">strain</span> rate in the mantle of eight long-finned squid Doryteuthis pealeii and two oval squid Sepioteuthis lessoniana. Transmural gradients of circumferential <span class="hlt">strain</span> were present during all jets (n = 312); i.e. for a given change in the circumference of the outer surface of the mantle, the inner surface experienced a greater proportional change. The magnitude of the difference increased with the amplitude of the mantle movement, with circular muscle fibres at the inner surface of the mantle experiencing a total range of <span class="hlt">strains</span> up to 1.45 times greater than fibres at the outer surface during vigorous jets. Differences in <span class="hlt">strain</span> rate between the circular fibres near the inner versus the outer surface of the mantle were also present in all jets, with the greatest differences occurring during vigorous jetting. The transmural gradients of circumferential <span class="hlt">strain</span> and <span class="hlt">strain</span> rate we describe probably apply not only to squids and other coleoid cephalopods, but also to diverse soft-bodied invertebrates with hollow cylindrical or conical bodies and muscular organs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4567374','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4567374"><span>Genome-Wide Transcription Study of Cryptococcus neoformans H99 Clinical <span class="hlt">Strain</span> versus Environmental <span class="hlt">Strains</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Movahed, Elaheh; Munusamy, Komathy; Tan, Grace Min Yi; Looi, Chung Yeng; Tay, Sun Tee; Wong, Won Fen</p> <p>2015-01-01</p> <p>The infection of Cryptococcus neoformans is acquired through the inhalation of desiccated yeast cells and basidiospores originated from the environment, particularly from bird’s droppings and decaying wood. Three environmental <span class="hlt">strains</span> of C. neoformans originated from bird droppings (H4, S48B and S68B) and C. neoformans reference clinical <span class="hlt">strain</span> (H99) were used for intranasal infection in C57BL/6 mice. We showed that the H99 <span class="hlt">strain</span> demonstrated higher virulence compared to H4, S48B and S68B <span class="hlt">strains</span>. To examine if gene expression contributed to the different degree of virulence among these <span class="hlt">strains</span>, a genome-wide microarray study was performed to inspect the transcriptomic profiles of all four <span class="hlt">strains</span>. Our results revealed that out of 7,419 genes (22,257 probes) examined, 65 genes were significantly up-or down-regulated in H99 versus H4, S48B and S68B <span class="hlt">strains</span>. The up-regulated genes in H99 <span class="hlt">strain</span> include Hydroxymethylglutaryl-CoA synthase (MVA1), Mitochondrial matrix factor 1 (MMF1), Bud-site-selection protein 8 (BUD8), High affinity glucose transporter 3 (SNF3) and Rho GTPase-activating protein 2 (RGA2). Pathway annotation using DAVID bioinformatics resource showed that metal ion binding and sugar transmembrane transporter activity pathways were highly expressed in the H99 <span class="hlt">strain</span>. We suggest that the genes and pathways identified may possibly play crucial roles in the fungal pathogenesis. PMID:26360021</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/960184','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/960184"><span>Stress-<span class="hlt">Strain</span> Relation and <span class="hlt">strain</span>-Induced Crystallization in Rubber</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Toki,S.</p> <p>2006-01-01</p> <p>Rubber is composed of flexible chains and network points. Theory of rubber elasticity succeeds to elucidate stress-<span class="hlt">strain</span> relation of rubber using the inverse Langevin equation of entropy modulus. However, actual rubber is much different from ideal networks composed of ideal rubber chains. Network points may not distribute homogeneously and the molecular weight between two network points may show wide distribution. Flexible chains show <span class="hlt">strain</span>-induced crystallization. Recent synchrotron X-ray and simultaneous stress-<span class="hlt">strain</span> measurements reveal that <span class="hlt">strain</span>-induced crystallization reduces the stress by increasing the length of molecules along the stretching direction. Also, <span class="hlt">strain</span>-induced crystals are created not at the middle of the network points, but at the close location to the network points. The hybrid structure of <span class="hlt">strain</span>-induced crystallites and network points may be stronger than network points alone. Therefore, <span class="hlt">strain</span> induced crystallization may increase the tensile strength of rubber by two mechanisms, they are, increase of elongation at break and reinforcement of network points. Natural rubber has biotic network points in nature. After vulcanization, the biotic network may contribute the superior toughness of NR, comparing to IR. Carbon filled NR also shows <span class="hlt">strain</span> induced crystallization. In order to acquire high tensile strength, molecules should have higher flexibility to perform <span class="hlt">strain</span> induced crystallization by selecting a kind of carbon blacks, an accelerator and a curing condition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/305920','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/305920"><span>The influence of <span class="hlt">strain</span> rate and hydrogen on the plane-<span class="hlt">strain</span> ductility of Zircaloy cladding</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Link, T.M.; Motta, A.T.; Koss, D.A.</p> <p>1998-03-01</p> <p>The authors studied the ductility of unirradiated Zircaloy-4 cladding under loading conditions prototypical of those found in reactivity-initiated accidents (RIA), i.e.: near plane-<span class="hlt">strain</span> deformation in the hoop direction (transverse to the cladding axis) at room temperature and 300 C and high <span class="hlt">strain</span> rates. To conduct these studies, they developed a specimen configuration in which near plane-<span class="hlt">strain</span> deformation is achieved in the gage section, and a testing methodology that allows one to determine both the limit <span class="hlt">strain</span> at the onset of localized necking and the fracture <span class="hlt">strain</span>. The experiments indicate that there is little effect of <span class="hlt">strain</span> rate (10{sup {minus}3} to 10{sup 2} s{sup {minus}1}) on the ductility of unhydrided Zircaloy tubing deformed under near plane-<span class="hlt">strain</span> conditions at either room temperature or 300 C. Preliminary experiments on cladding containing 190 ppm hydrogen show only a small loss of fracture <span class="hlt">strain</span> but no clear effect on limit <span class="hlt">strain</span>. The experiments also indicate that there is a significant loss of Zircaloy ductility when surface flaws are present in the form of thickness imperfections.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18851573','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18851573"><span>Influence of <span class="hlt">strain</span> on the conduction band structure of <span class="hlt">strained</span> silicon nanomembranes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Euaruksakul, C; Li, Z W; Zheng, F; Himpsel, F J; Ritz, C S; Tanto, B; Savage, D E; Liu, X S; Lagally, M G</p> <p>2008-10-03</p> <p>The influence of in-plane biaxial <span class="hlt">strain</span> on the conduction bands of Si is explored using elastically <span class="hlt">strained</span> Si(001) nanomembranes and high-resolution x-ray absorption measurements with electron yield detection. The <span class="hlt">strain</span>-induced splitting of the conduction band minimum and the energy shifts of two higher conduction bands near L1 and L3 are clearly resolved. The linear increase of the splitting of the conduction band minimum with increasing <span class="hlt">strain</span> and the nonlinear shift of the L1 point toward the conduction band minimum agree quantitatively with current theories.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016CMT....28..977A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016CMT....28..977A"><span>A numerical method for determining the <span class="hlt">strain</span> rate intensity factor under plane <span class="hlt">strain</span> conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alexandrov, S.; Kuo, C.-Y.; Jeng, Y.-R.</p> <p>2016-07-01</p> <p>Using the classical model of rigid perfectly plastic solids, the <span class="hlt">strain</span> rate intensity factor has been previously introduced as the coefficient of the leading singular term in a series expansion of the equivalent <span class="hlt">strain</span> rate in the vicinity of maximum friction surfaces. Since then, many <span class="hlt">strain</span> rate intensity factors have been determined by means of analytical and semi-analytical solutions. However, no attempt has been made to develop a numerical method for calculating the <span class="hlt">strain</span> rate intensity factor. This paper presents such a method for planar flow. The method is based on the theory of characteristics. First, the <span class="hlt">strain</span> rate intensity factor is derived in characteristic coordinates. Then, a standard numerical slip-line technique is supplemented with a procedure to calculate the <span class="hlt">strain</span> rate intensity factor. The distribution of the <span class="hlt">strain</span> rate intensity factor along the friction surface in compression of a layer between two parallel plates is determined. A high accuracy of this numerical solution for the <span class="hlt">strain</span> rate intensity factor is confirmed by comparison with an analytic solution. It is shown that the distribution of the <span class="hlt">strain</span> rate intensity factor is in general discontinuous.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016RScI...87j2506M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016RScI...87j2506M"><span>On the use of <span class="hlt">strain</span> sensor technologies for <span class="hlt">strain</span> modal analysis: Case studies in aeronautical applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marques dos Santos, Fábio Luis; Peeters, Bart</p> <p>2016-10-01</p> <p>This paper discusses the use of optical fiber Bragg grating (FBG) and piezo <span class="hlt">strain</span> sensors for structural dynamic measurements. For certain industrial applications, there is an interest to use <span class="hlt">strain</span> sensors rather than in combination with accelerometers for experimental modal analysis. Classical electrical <span class="hlt">strain</span> gauges can be used hereto, but other types of <span class="hlt">strain</span> sensors are an interesting alternative with some very specific advantages. This work gives an overview of two types of dynamic <span class="hlt">strain</span> sensors, applied to two industrial applications (a helicopter main rotor blade and an F-16 aircraft), FBG sensors and dynamic piezo <span class="hlt">strain</span> sensors, discussing their use and benefits. Moreover, the concept of <span class="hlt">strain</span> modal analysis is introduced and it is shown how it can be beneficial to apply <span class="hlt">strain</span> measurements to experimental modal analysis. Finally, experimental results for the two applications are shown, with an experimental modal analysis carried out on the helicopter main rotor blade using FBG sensors and a similar experiment is done with the aircraft but using piezo <span class="hlt">strain</span> sensors instead.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26063842','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26063842"><span>Bone <span class="hlt">strain</span> magnitude is correlated with bone <span class="hlt">strain</span> rate in tetrapods: implications for models of mechanotransduction.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Aiello, B R; Iriarte-Diaz, J; Blob, R W; Butcher, M T; Carrano, M T; Espinoza, N R; Main, R P; Ross, C F</p> <p>2015-07-07</p> <p>Hypotheses suggest that structural integrity of vertebrate bones is maintained by controlling bone <span class="hlt">strain</span> magnitude via adaptive modelling in response to mechanical stimuli. Increased tissue-level <span class="hlt">strain</span> magnitude and rate have both been identified as potent stimuli leading to increased bone formation. Mechanotransduction models hypothesize that osteocytes sense bone deformation by detecting fluid flow-induced drag in the bone's lacunar-canalicular porosity. This model suggests that the osteocyte's intracellular response depends on fluid-flow rate, a product of bone <span class="hlt">strain</span> rate and gradient, but does not provide a mechanism for detection of <span class="hlt">strain</span> magnitude. Such a mechanism is necessary for bone modelling to adapt to loads, because <span class="hlt">strain</span> magnitude is an important determinant of skeletal fracture. Using <span class="hlt">strain</span> gauge data from the limb bones of amphibians, reptiles, birds and mammals, we identified strong correlations between <span class="hlt">strain</span> rate and magnitude across clades employing diverse locomotor styles and degrees of rhythmicity. The breadth of our sample suggests that this pattern is likely to be a common feature of tetrapod bone loading. Moreover, finding that bone <span class="hlt">strain</span> magnitude is encoded in <span class="hlt">strain</span> rate at the tissue level is consistent with the hypothesis that it might be encoded in fluid-flow rate at the cellular level, facilitating bone adaptation via mechanotransduction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4590470','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4590470"><span>Bone <span class="hlt">strain</span> magnitude is correlated with bone <span class="hlt">strain</span> rate in tetrapods: implications for models of mechanotransduction</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Aiello, B. R.; Iriarte-Diaz, J.; Blob, R. W.; Butcher, M. T.; Carrano, M. T.; Espinoza, N. R.; Main, R. P.; Ross, C. F.</p> <p>2015-01-01</p> <p>Hypotheses suggest that structural integrity of vertebrate bones is maintained by controlling bone <span class="hlt">strain</span> magnitude via adaptive modelling in response to mechanical stimuli. Increased tissue-level <span class="hlt">strain</span> magnitude and rate have both been identified as potent stimuli leading to increased bone formation. Mechanotransduction models hypothesize that osteocytes sense bone deformation by detecting fluid flow-induced drag in the bone's lacunar–canalicular porosity. This model suggests that the osteocyte's intracellular response depends on fluid-flow rate, a product of bone <span class="hlt">strain</span> rate and gradient, but does not provide a mechanism for detection of <span class="hlt">strain</span> magnitude. Such a mechanism is necessary for bone modelling to adapt to loads, because <span class="hlt">strain</span> magnitude is an important determinant of skeletal fracture. Using <span class="hlt">strain</span> gauge data from the limb bones of amphibians, reptiles, birds and mammals, we identified strong correlations between <span class="hlt">strain</span> rate and magnitude across clades employing diverse locomotor styles and degrees of rhythmicity. The breadth of our sample suggests that this pattern is likely to be a common feature of tetrapod bone loading. Moreover, finding that bone <span class="hlt">strain</span> magnitude is encoded in <span class="hlt">strain</span> rate at the tissue level is consistent with the hypothesis that it might be encoded in fluid-flow rate at the cellular level, facilitating bone adaptation via mechanotransduction. PMID:26063842</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26360021','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26360021"><span>Genome-Wide Transcription Study of Cryptococcus neoformans H99 Clinical <span class="hlt">Strain</span> versus Environmental <span class="hlt">Strains</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Movahed, Elaheh; Munusamy, Komathy; Tan, Grace Min Yi; Looi, Chung Yeng; Tay, Sun Tee; Wong, Won Fen</p> <p>2015-01-01</p> <p>The infection of Cryptococcus neoformans is acquired through the inhalation of desiccated yeast cells and basidiospores originated from the environment, particularly from bird's droppings and decaying wood. Three environmental <span class="hlt">strains</span> of C. neoformans originated from bird droppings (H4, S48B and S68B) and C. neoformans reference clinical <span class="hlt">strain</span> (H99) were used for intranasal infection in C57BL/6 mice. We showed that the H99 <span class="hlt">strain</span> demonstrated higher virulence compared to H4, S48B and S68B <span class="hlt">strains</span>. To examine if gene expression contributed to the different degree of virulence among these <span class="hlt">strains</span>, a genome-wide microarray study was performed to inspect the transcriptomic profiles of all four <span class="hlt">strains</span>. Our results revealed that out of 7,419 genes (22,257 probes) examined, 65 genes were significantly up-or down-regulated in H99 versus H4, S48B and S68B <span class="hlt">strains</span>. The up-regulated genes in H99 <span class="hlt">strain</span> include Hydroxymethylglutaryl-CoA synthase (MVA1), Mitochondrial matrix factor 1 (MMF1), Bud-site-selection protein 8 (BUD8), High affinity glucose transporter 3 (SNF3) and Rho GTPase-activating protein 2 (RGA2). Pathway annotation using DAVID bioinformatics resource showed that metal ion binding and sugar transmembrane transporter activity pathways were highly expressed in the H99 <span class="hlt">strain</span>. We suggest that the genes and pathways identified may possibly play crucial roles in the fungal pathogenesis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APLM....4f4107S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APLM....4f4107S"><span>Elastocaloric cooling processes: The influence of material <span class="hlt">strain</span> and <span class="hlt">strain</span> rate on efficiency and temperature span</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schmidt, Marvin; Schütze, Andreas; Seelecke, Stefan</p> <p>2016-06-01</p> <p>This paper discusses the influence of material <span class="hlt">strain</span> and <span class="hlt">strain</span> rate on efficiency and temperature span of elastocaloric cooling processes. The elastocaloric material, a newly developed quaternary Ni-Ti-Cu-V alloy, is characterized at different maximum <span class="hlt">strains</span> and <span class="hlt">strain</span> rates. The experiments are performed with a specially designed test setup, which enables the measurement of mechanical and thermal process parameters. The material efficiency is compared to the efficiency of the Carnot process at equivalent thermal operation conditions. This method allows for a direct comparison of the investigated material with other caloric materials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://dx.doi.org/10.1785/0220160155','USGSPUBS'); return false;" href="https://dx.doi.org/10.1785/0220160155"><span>Dynamic <span class="hlt">strains</span> for earthquake source characterization</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Barbour, Andrew J.; Crowell, Brendan W</p> <p>2017-01-01</p> <p>Strainmeters measure elastodynamic deformation associated with earthquakes over a broad frequency band, with detection characteristics that complement traditional instrumentation, but they are commonly used to study slow transient deformation along active faults and at subduction zones, for example. Here, we analyze dynamic <span class="hlt">strains</span> at Plate Boundary Observatory (PBO) borehole strainmeters (BSM) associated with 146 local and regional earthquakes from 2004–2014, with magnitudes from M 4.5 to 7.2. We find that peak values in seismic <span class="hlt">strain</span> can be predicted from a general regression against distance and magnitude, with improvements in accuracy gained by accounting for biases associated with site–station effects and source–path effects, the latter exhibiting the strongest influence on the regression coefficients. To account for the influence of these biases in a general way, we include crustal‐type classifications from the CRUST1.0 global velocity model, which demonstrates that high‐frequency <span class="hlt">strain</span> data from the PBO BSM network carry information on crustal structure and fault mechanics: earthquakes nucleating offshore on the Blanco fracture zone, for example, generate consistently lower dynamic <span class="hlt">strains</span> than earthquakes around the Sierra Nevada microplate and in the Salton trough. Finally, we test our dynamic <span class="hlt">strain</span> prediction equations on the 2011 M 9 Tohoku‐Oki earthquake, specifically continuous <span class="hlt">strain</span> records derived from triangulation of 137 high‐rate Global Navigation Satellite System Earth Observation Network stations in Japan. Moment magnitudes inferred from these data and the <span class="hlt">strain</span> model are in agreement when Global Positioning System subnetworks are unaffected by spatial aliasing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15076778','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15076778"><span>Predicting hamstring <span class="hlt">strain</span> injury in elite athletes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Brockett, Camilla L; Morgan, David L; Proske, Uwe</p> <p>2004-03-01</p> <p>Eccentric exercise, where the contracting muscle is lengthened, produces microscopic damage in muscle fibers, and sensations of stiffness and soreness, the next day. These normally resolve within a week. A more major sports injury is the muscle <span class="hlt">strain</span>. Because <span class="hlt">strain</span> injuries are known to occur during eccentric contractions, it is hypothesized that the microscopic damage from eccentric exercise can, at times, progress to a muscle <span class="hlt">strain</span>. As the amount of microscopic damage depends on the muscle's optimum length for active tension, it is further proposed that optimum length is a measure of susceptibility for muscle <span class="hlt">strains</span>. The athletes most at risk of a hamstring <span class="hlt">strain</span> are those with a previous history of such injuries. Here the prediction is tested that optimum lengths of previously injured hamstrings are shorter and therefore more prone to eccentric damage than uninjured muscles. Mean optimum angle for peak torque in a previously injured muscle of nine athletes with a history of unilateral hamstring <span class="hlt">strains</span> was compared with the uninjured muscle of the other leg and with muscles of 18 uninjured athletes. Optimum angle was determined with isokinetic dynamometry. In previously injured muscles, torque peaked at significantly shorter lengths than for uninjured muscles. Peak torque and quadriceps:hamstrings torque ratios were not significantly different. The shorter optimum of previously injured muscles makes them more prone to damage from eccentric exercise than uninjured muscles and this may account for the high reinjury rate. The shorter optimum may reflect the muscle's preinjury state or be a consequence of the healing process. To reduce the incidence of <span class="hlt">strain</span> injuries, it is recommended that a combined program of eccentric exercise and muscle testing be carried out.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1989JSG....11..959J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1989JSG....11..959J"><span>Fault-fracture <span class="hlt">strain</span> in Wingate Sandstone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jamison, William R.</p> <p></p> <p>The Laramide deformation of the Triassic Wingate Sandstone along the northeast flank of the Uncompahgre uplift has occurred by faulting at various scales. Macroscopically smooth flexures of beds within the Wingate occur by small displacements across a myriad of intraformational, mesoscale faults. The deformation resultant from these small faults may be approximated by a <span class="hlt">strain</span> tensor, provided the measurement domain satisfies certain size criteria. Equivalent <span class="hlt">strain</span> (ɛ) measurements, obtained from 22 locations in the East Kodel's Canyon, range from 1% to 15.5% (the maximum contractional <span class="hlt">strains</span> range from -0.9% to -13.4%). The faults producing this <span class="hlt">strain</span> have displacements ranging from a fraction of a millimeter to 18.5 cm. The fault intensity increases with increasing ɛ, although in a distinctly non-linear fashion. At low <span class="hlt">strains</span>, incremental increases in the deformation produce additional, small displacement faults. At larger <span class="hlt">strains</span>, incremental increases in the deformation occur via progressive displacement along existing faults. The principal <span class="hlt">strain</span> axes are consistently non-coaxial with the inferred principal stresses (average σ1Λɛ1 is 18.5°). This non-coaxiality results from the non-uniform development of the conjugate fault systems. This same inequality of the conjugate systems produces a non-zero rotation tensor, ω, but ω is not related to σ1Λɛ1. The non-uniform development of conjugate shears (and the associated non-coaxiality of σ1 and ɛ1) may be an intrinsic characteristic of a Coulomb material.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20215607','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20215607"><span>Volume <span class="hlt">strain</span> within the Geysers geothermal field</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mossop, Antony; Segall, Paul</p> <p>1999-12-10</p> <p>During the 1970s and 1980s. The Geysers geothermal region was rapidly developed as a site of geothermal power production. The likelihood that this could cause significant <span class="hlt">strain</span> within the reservoir, with corresponding surface displacements, led to a series of deformation monitoring surveys. In 1973, 1975, 1977, and 1980, The Geysers region was surveyed using first-order, class I, spirit leveling. In 1994, 1995, and 1996, many of the leveling control monuments were resurveyed using high-precision Global Positioning System receivers. The two survey methods are reconciled using the GEOID96 geoid model. The displacements are inverted to determine volume <span class="hlt">strain</span> within the reservoir. For the period 1980-1994, peak volume <span class="hlt">strains</span> in excess of 5x10{sup -4} are imaged. There is an excellent correlation between the observed changes in reservoir steam pressures and the imaged volume <span class="hlt">strain</span>. If reservoir pressure changes are inducing volume <span class="hlt">strain</span>, then the reservoir quasi-static bulk modulus K must be <4.6x10{sup 9} Pa. However, seismic velocities indicate a much stiffer reservoir with K=3.4x10{sup 10} Pa. This apparent discrepancy is shown to be consistent with predicted frequency dependence in K for fractured and water-saturated rock. Inversion of surface deformation data therefore appears to be a powerful method for imaging pressure change within the body of the reservoir. Correlation between induced seismicity at The Geysers and volume <span class="hlt">strain</span> is observed. However, earthquake distribution does not appear to have a simple relationship with volume <span class="hlt">strain</span> rate. (c) 1999 American Geophysical Union.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016hsla.book..179Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016hsla.book..179Q"><span>Determination of Dynamic Recrystallization Process by Equivalent <span class="hlt">Strain</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Qin, Xiaomei; Deng, Wei</p> <p></p> <p>Based on Tpнoвckiй's displacement field, equivalent <span class="hlt">strain</span> expression was derived. And according to the dynamic recrystallization (DRX) critical <span class="hlt">strain</span>, DRX process was determined by equivalent <span class="hlt">strain</span>. It was found that equivalent <span class="hlt">strain</span> distribution in deformed specimen is inhomogeneous, and it increases with increasing true <span class="hlt">strain</span>. Under a certain true <span class="hlt">strain</span>, equivalent <span class="hlt">strains</span> at the center, demisemi radius or on tangential plane just below the surface of the specimen are higher than the true <span class="hlt">strain</span>. Thus, micrographs at those positions can not exactly reflect the true microstructures under the certain true <span class="hlt">strain</span>. With increasing <span class="hlt">strain</span> rate, the initial and finish time of DRX decrease. The frozen microstructures of 20Mn23AlV steel with the experimental condition validate the feasibility of predicting DRX process by equivalent <span class="hlt">strain</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23462347','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23462347"><span>Psychological <span class="hlt">strains</span> found in the suicides of 72 celebrities.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Jie; Tan, Jiandan; Lester, David</p> <p>2013-07-01</p> <p>The interpretation of suicide involves theories from many disciplines, and the <span class="hlt">strain</span> theory of suicide is a social-psychological model that attempts to account for this complicated behavior. We have earlier explored the presence of psychological <span class="hlt">strains</span> in a number of diverse samples of suicides and in the present study, we identified the <span class="hlt">strains</span> experienced throughout the lives as documented in the biographies of 72 celebrities. The biographies were systematically identified through a number of requirements and composed by one of the authors of this study years before the <span class="hlt">strain</span> theory of suicide was proposed. A graduate student coder, who was unaware of the <span class="hlt">strain</span> theory of suicide, was hired to carry out a content analysis of the biography essays and categorize the life events and the responses of the suicide in terms of the four types of <span class="hlt">strains</span>. Of the 72 suicides, one had no <span class="hlt">strains</span>, one had all the four <span class="hlt">strains</span>, four had only one, 30 had two, and 36 had three <span class="hlt">strains</span>. The most common <span class="hlt">strain</span> was aspiration <span class="hlt">strain</span> (97%), followed by deprivation <span class="hlt">strain</span> (89%), value <span class="hlt">strain</span> (54%) and coping deficiency <span class="hlt">strain</span> (4%). It is also noted that religious celebrities were more likely to experience value <span class="hlt">strain</span>, while those celebrities who had experienced a downhill path in their careers were more likely to experience deprivation and coping <span class="hlt">strains</span>. This analysis of the 72 celebrity suicides supported the <span class="hlt">strain</span> theory of suicide.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17093023','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17093023"><span><span class="hlt">Strain</span>-specific single-nucleotide polymorphism assays for the Bacillus anthracis Ames <span class="hlt">strain</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Van Ert, Matthew N; Easterday, W Ryan; Simonson, Tatum S; U'Ren, Jana M; Pearson, Talima; Kenefic, Leo J; Busch, Joseph D; Huynh, Lynn Y; Dukerich, Megan; Trim, Carla B; Beaudry, Jodi; Welty-Bernard, Amy; Read, Timothy; Fraser, Claire M; Ravel, Jacques; Keim, Paul</p> <p>2007-01-01</p> <p>Highly precise diagnostics and forensic assays can be developed through a combination of evolutionary analysis and the exhaustive examination of genomic sequences. In Bacillus anthracis, whole-genome sequencing efforts revealed ca. 3,500 single-nucleotide polymorphisms (SNPs) among eight different <span class="hlt">strains</span> and evolutionary analysis provides the identification of canonical SNPs. We have previously shown that SNPs are highly evolutionarily stable, and the clonal nature of B. anthracis makes them ideal signatures for subtyping this pathogen. Here we identified SNPs that define the lineage of B. anthracis that contains the Ames <span class="hlt">strain</span>, the <span class="hlt">strain</span> used in the 2001 bioterrorist attacks in the United States. Sequencing and real-time PCR were used to validate these SNPs across B. anthracis <span class="hlt">strains</span>, including (i) 88 globally and genetically diverse isolates; (ii) isolates that were shown to be genetic relatives of the Ames <span class="hlt">strain</span> by multiple-locus variable number tandem repeat analysis (MLVA); and (iii) several different lab stocks of the Ames <span class="hlt">strain</span>, including a clinical isolate from the 2001 letter attack. Six SNPs were found to be highly specific for the Ames <span class="hlt">strain</span>; four on the chromosome, one on the pX01 plasmid, and one on the pX02 plasmid. All six SNPs differentiated the B. anthracis Ames <span class="hlt">strain</span> from the 88 unique B. anthracis <span class="hlt">strains</span>, while five of the six separated Ames from its close genetic relatives. The use of these SNPs coupled with real-time PCR allows specific and sensitive (<100 fg of template DNA) identification of the Ames <span class="hlt">strain</span>. This evolutionary and genomics-based approach provides an effective means for the discovery of <span class="hlt">strain</span>-specific SNPs in B. anthracis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19810062035&hterms=behavior+analysis&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dbehavior%2Banalysis','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19810062035&hterms=behavior+analysis&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dbehavior%2Banalysis"><span>Analysis of the tensile stress-<span class="hlt">strain</span> behavior of elastomers at constant <span class="hlt">strain</span> rates. I - Criteria for separability of the time and <span class="hlt">strain</span> effects</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hong, S. D.; Fedors, R. F.; Schwarzl, F.; Moacanin, J.; Landel, R. F.</p> <p>1981-01-01</p> <p>A theoretical analysis of the tensile stress-<span class="hlt">strain</span> relation of elastomers at constant <span class="hlt">strain</span> rate is presented which shows that the time and the stress effect are separable if the experimental time scale coincides with a segment of the relaxation modulus that can be described by a single power law. It is also shown that time-<span class="hlt">strain</span> separability is valid if the <span class="hlt">strain</span> function is linearly proportional to the Cauchy <span class="hlt">strain</span>, and that when time-<span class="hlt">strain</span> separability holds, two <span class="hlt">strain</span>-dependent quantities can be obtained experimentally. In the case where time and <span class="hlt">strain</span> effect are not separable, superposition can be achieved only by using temperature and <span class="hlt">strain</span>-dependent shift factors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19810062035&hterms=stress-strain&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dstress-strain','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19810062035&hterms=stress-strain&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dstress-strain"><span>Analysis of the tensile stress-<span class="hlt">strain</span> behavior of elastomers at constant <span class="hlt">strain</span> rates. I - Criteria for separability of the time and <span class="hlt">strain</span> effects</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hong, S. D.; Fedors, R. F.; Schwarzl, F.; Moacanin, J.; Landel, R. F.</p> <p>1981-01-01</p> <p>A theoretical analysis of the tensile stress-<span class="hlt">strain</span> relation of elastomers at constant <span class="hlt">strain</span> rate is presented which shows that the time and the stress effect are separable if the experimental time scale coincides with a segment of the relaxation modulus that can be described by a single power law. It is also shown that time-<span class="hlt">strain</span> separability is valid if the <span class="hlt">strain</span> function is linearly proportional to the Cauchy <span class="hlt">strain</span>, and that when time-<span class="hlt">strain</span> separability holds, two <span class="hlt">strain</span>-dependent quantities can be obtained experimentally. In the case where time and <span class="hlt">strain</span> effect are not separable, superposition can be achieved only by using temperature and <span class="hlt">strain</span>-dependent shift factors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhDT.......536S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhDT.......536S"><span>Anisotropic nature of radially <span class="hlt">strained</span> metal tubes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Strickland, Julie N.</p> <p></p> <p>Metal pipes are sometimes swaged by a metal cone to enlarge them, which increases the <span class="hlt">strain</span> in the material. The amount of <span class="hlt">strain</span> is important because it affects the burst and collapse strength. Burst strength is the amount of internal pressure that a pipe can withstand before failure, while collapse strength is the amount of external pressure that a pipe can withstand before failure. If the burst or collapse strengths are exceeded, the pipe may fracture, causing critical failure. Such an event could cost the owners and their customers millions of dollars in clean up, repair, and lost time, in addition to the potential environmental damage. Therefore, a reliable way of estimating the burst and collapse strength of <span class="hlt">strained</span> pipe is desired and valuable. The sponsor currently rates <span class="hlt">strained</span> pipes using the properties of raw steel, because those properties are easily measured (for example, yield strength). In the past, the engineers assumed that the metal would be work-hardened when swaged, so that yield strength would increase. However, swaging introduces anisotropic <span class="hlt">strain</span>, which may decrease the yield strength. This study measured the yield strength of <span class="hlt">strained</span> material in the transverse and axial direction and compared them to raw material, to determine the amount of anisotropy. This information will be used to more accurately determine burst and collapse ratings for <span class="hlt">strained</span> pipes. More accurate ratings mean safer products, which will minimize risk for the sponsor's customers. Since the <span class="hlt">strained</span> metal has a higher yield strength than the raw material, using the raw yield strength to calculate burst and collapse ratings is a conservative method. The metal has even higher yield strength after <span class="hlt">strain</span> aging, which indicates that the stresses are relieved. Even with the 12% anisotropy in the <span class="hlt">strained</span> and 9% anisotropy in the <span class="hlt">strain</span> aged specimens, the raw yield strengths are lower and therefore more conservative. I recommend that the sponsor continue using the raw</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3942497','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3942497"><span>The Effect of Ivermectin in Seven <span class="hlt">Strains</span> of Aedes aegypti (Diptera: Culicidae) Including a Genetically Diverse Laboratory <span class="hlt">Strain</span> and Three Permethrin Resistant <span class="hlt">Strains</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Deus, K. M.; Saavedra-rodriguez, K.; Butters, M. P.; Black, W. C.; Foy, B. D.</p> <p>2014-01-01</p> <p>Seven different <span class="hlt">strains</span> of Aedes aegypti (L.), including a genetically diverse laboratory <span class="hlt">strain</span>, three laboratory-selected permethrin-resistant <span class="hlt">strains</span>, a standard reference <span class="hlt">strain</span>, and two recently colonized <span class="hlt">strains</span> were fed on human blood containing various concentrations of ivermectin. Ivermectin reduced adult survival, fecundity, and hatch rate of eggs laid by ivermectin-treated adults in all seven <span class="hlt">strains</span>. The LC50 of ivermectin for adults and the concentration that prevented 50% of eggs from hatching was calculated for all <span class="hlt">strains</span>. Considerable variation in adult survival after an ivermectin-bloodmeal occurred among <span class="hlt">strains</span>, and all three permethrin-resistant <span class="hlt">strains</span> were significantly less susceptible to ivermectin than the standard reference <span class="hlt">strain</span>. The hatch rate after an ivermectin bloodmeal was less variable among <span class="hlt">strains</span>, and only one of the permethrin-resistant <span class="hlt">strains</span> differed significantly from the standard reference <span class="hlt">strain</span>. Our studies suggest that ivermectin induces adult mortality and decreases the hatch rate of eggs through different mechanisms. A correlation analysis of log-transformed LC50 among <span class="hlt">strains</span> suggests that permethrin and ivermectin cross-resistance may occur. PMID:22493855</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2395655','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2395655"><span>Mixing of Schistosoma haematobium <span class="hlt">strains</span> in Ghana*</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chu, K. Y.; Kpo, H. K.; Klumpp, R. K.</p> <p>1978-01-01</p> <p>In Ghana, Schistosoma haematobium exists as two <span class="hlt">strains</span>, one transmitted by Bulinus rohlfsi and the other by B. globosus. In Anyaboni, a resettlement town, where the field station of the UNDP/WHO Schistosomiasis Research and Control Project is located, the residents contract the ”rohlfsi” <span class="hlt">strain</span> of the parasite from the Volta Lake and the ”globosus” <span class="hlt">strain</span> from a stream near the town. The present studies indicate that there is mixing of the two parasite <span class="hlt">strains</span> on a community and an individual basis. In Anyaboni, the parasite developed well in both B. rohlfsi and B. globosus. In another village 25 km from Accra, where B. globosus was the only vector, the parasite developed well in B. globosus but was refractory in B. rohlfsi. In a village near the Volta Lake where B. rohlfsi was the sole vector, the parasite developed well in B. rohlfsi but was refractory in B. globosus. However, complete separation of the two <span class="hlt">strains</span> is uncommon in Ghana because extensive mixing has already occurred owing to migration of people and snails. PMID:310361</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23416347','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23416347"><span>Fast flexible electronics with <span class="hlt">strained</span> silicon nanomembranes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhou, Han; Seo, Jung-Hun; Paskiewicz, Deborah M; Zhu, Ye; Celler, George K; Voyles, Paul M; Zhou, Weidong; Lagally, Max G; Ma, Zhenqiang</p> <p>2013-01-01</p> <p>Fast flexible electronics operating at radio frequencies (>1 GHz) are more attractive than traditional flexible electronics because of their versatile capabilities, dramatic power savings when operating at reduced speed and broader spectrum of applications. Transferrable single-crystalline Si nanomembranes (SiNMs) are preferred to other materials for flexible electronics owing to their unique advantages. Further improvement of Si-based device speed implies significant technical and economic advantages. While the mobility of bulk Si can be enhanced using <span class="hlt">strain</span> techniques, implementing these techniques into transferrable single-crystalline SiNMs has been challenging and not demonstrated. The past approach presents severe challenges to achieve effective doping and desired material topology. Here we demonstrate the combination of <span class="hlt">strained</span>- NM-compatible doping techniques with self-sustained-<span class="hlt">strain</span> sharing by applying a <span class="hlt">strain</span>-sharing scheme between Si and SiGe multiple epitaxial layers, to create <span class="hlt">strained</span> print-transferrable SiNMs. We demonstrate a new speed record of Si-based flexible electronics without using aggressively scaled critical device dimensions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3575016','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3575016"><span>Fast flexible electronics with <span class="hlt">strained</span> silicon nanomembranes</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhou, Han; Seo, Jung-Hun; Paskiewicz, Deborah M.; Zhu, Ye; Celler, George K.; Voyles, Paul M.; Zhou, Weidong; Lagally, Max G.; Ma, Zhenqiang</p> <p>2013-01-01</p> <p>Fast flexible electronics operating at radio frequencies (>1 GHz) are more attractive than traditional flexible electronics because of their versatile capabilities, dramatic power savings when operating at reduced speed and broader spectrum of applications. Transferrable single-crystalline Si nanomembranes (SiNMs) are preferred to other materials for flexible electronics owing to their unique advantages. Further improvement of Si-based device speed implies significant technical and economic advantages. While the mobility of bulk Si can be enhanced using <span class="hlt">strain</span> techniques, implementing these techniques into transferrable single-crystalline SiNMs has been challenging and not demonstrated. The past approach presents severe challenges to achieve effective doping and desired material topology. Here we demonstrate the combination of <span class="hlt">strained</span>- NM-compatible doping techniques with self-sustained-<span class="hlt">strain</span> sharing by applying a <span class="hlt">strain</span>-sharing scheme between Si and SiGe multiple epitaxial layers, to create <span class="hlt">strained</span> print-transferrable SiNMs. We demonstrate a new speed record of Si-based flexible electronics without using aggressively scaled critical device dimensions. PMID:23416347</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19860008318','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19860008318"><span>Closure of fatigue cracks at high <span class="hlt">strains</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Iyyer, N. S.; Dowling, N. E.</p> <p>1985-01-01</p> <p>Experiments were conducted on smooth specimens to study the closure behavior of short cracks at high cyclic <span class="hlt">strains</span> under completely reversed cycling. Testing procedures and methodology, and closure measurement techniques, are described in detail. The <span class="hlt">strain</span> levels chosen for the study cover from predominantly elastic to grossly plastic <span class="hlt">strains</span>. Crack closure measurements are made at different crack lengths. The study reveals that, at high <span class="hlt">strains</span>, cracks close only as the lowest stress level in the cycle is approached. The crack opening is observed to occur in the compressive part of the loading cycle. The applied stress needed to open a short crack under high <span class="hlt">strain</span> is found to be less than for cracks under small scale yielding. For increased plastic deformations, the value of sigma sub op/sigma sub max is observed to decrease and approaches the value of R. Comparison of the experimental results with existing analysis is made and indicates the limitations of the small scale yielding approach where gross plastic deformation behavior occurs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25111022','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25111022"><span>Genomics of Clostridium botulinum group III <span class="hlt">strains</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sakaguchi, Yoshihiko; Suzuki, Tomonori; Yamamoto, Yumiko; Nishikawa, Atsushi; Oguma, Keiji</p> <p>2015-05-01</p> <p>In Clostridium botulinum, the characteristics of type C and D <span class="hlt">strains</span> are quite different from other types, and they are classified as group III. They produce C2 binary toxin and C3 exoenzyme in addition to type C and D neurotoxins. Two different phages and many plasmids are identified in the organisms. The genes of neurotoxin and C3 exoenzyme are converted from toxigenic <span class="hlt">strains</span> to non-toxigenic <span class="hlt">strains</span> by the specific bacteriophages (phages), whereas, the C2 toxin gene is carried by large or small plasmids. Classification of type C and D <span class="hlt">strains</span> has been in confusion because 1) antigenicity of type C and D neurotoxins is complex, 2) the cells produce two types of toxins, neurotoxin and C2 toxin, and 3) some non-toxigenic <span class="hlt">strains</span> can be converted to produce C or D neurotoxin by the infection with phages. Until now, entire nucleotide sequences of cell chromosomes, phages, and plasmids have been determined. Since both genetic and protein-chemical analyses have been clarifying the above confusions, these data are reviewed historically.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4034219','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4034219"><span>Extraordinary <span class="hlt">strain</span> hardening by gradient structure</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wu, XiaoLei; Jiang, Ping; Chen, Liu; Yuan, Fuping; Zhu, Yuntian T.</p> <p>2014-01-01</p> <p>Gradient structures have evolved over millions of years through natural selection and optimization in many biological systems such as bones and plant stems, where the structures change gradually from the surface to interior. The advantage of gradient structures is their maximization of physical and mechanical performance while minimizing material cost. Here we report that the gradient structure in engineering materials such as metals renders a unique extra <span class="hlt">strain</span> hardening, which leads to high ductility. The grain-size gradient under uniaxial tension induces a macroscopic <span class="hlt">strain</span> gradient and converts the applied uniaxial stress to multiaxial stresses due to the evolution of incompatible deformation along the gradient depth. Thereby the accumulation and interaction of dislocations are promoted, resulting in an extra <span class="hlt">strain</span> hardening and an obvious <span class="hlt">strain</span> hardening rate up-turn. Such extraordinary <span class="hlt">strain</span> hardening, which is inherent to gradient structures and does not exist in homogeneous materials, provides a hitherto unknown strategy to develop strong and ductile materials by architecting heterogeneous nanostructures. PMID:24799688</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=236087','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=236087"><span>Transfectability of rough <span class="hlt">strains</span> of Salmonella typhimurium.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Bursztyn, H; Sgaramella, V; Ciferri, O; Lederberg, J</p> <p>1975-01-01</p> <p>Cells of rough (but not smooth) <span class="hlt">strains</span> of Salmonella typhimurium become competent for transfection by phage P22 deoxyribonucleic acid after treatment with 0.1 M CaCl2. The yield of infectious centers is about 10(-8) per genome equivalent of deoxyribonucleic acid. However, different sorts of rough <span class="hlt">strains</span> vary in their ability to become competent in a fashion that can be correlated with the level of the genetic block in cell wall lipopolysaccharide synthesis. The most amenable <span class="hlt">strains</span> are blocked by defects in the addition of galactose units I and II of the lipopolysaccharide by the inability to synthesize uridine 5'-diphosphate-galactose (galE point mutants and gal deletion mutants). <span class="hlt">Strains</span> blocked only in the addition of galactose I, glucose I, or heptose II have low levels of transfectability, whereas <span class="hlt">strains</span> with either more complete or more deficient lipopolysaccharide core are not competent for transfection. When normal lipopolysaccharide synthesis is restored either genetically or by furnishing exogenous galactose (galE point mutants that can still use it), the cells are not longer competent for transfection. PMID:1104596</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11874722','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11874722"><span>Growth <span class="hlt">strain</span> in coconut palm trees.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Huang, Yan S; Chen, Shin S; Lin, Tsan P; Chen, Yuh S</p> <p>2002-03-01</p> <p>Until recently, growth stress studies have been made only on coniferous and dicotyledonous trees. Growth stress of trees is thought to be initiated in newly formed secondary xylem cells. This stress can accumulate for years and is distributed inside the trunk. Major characteristics of the trunk of monocotyledonous trees include numerous vascular bundles scattered inside the ground tissue and the lack of secondary growth for enlarging the diameter of the trunk. We used the <span class="hlt">strain</span> gauge method to measure the released growth <span class="hlt">strain</span> of the monocotyledonous woody palm, coconut (Cocos nucifera L.), and to investigate the surface growth <span class="hlt">strain</span> of the trunk and central cylinder at different trunk heights. The internal <span class="hlt">strains</span> of both vertical and leaning trunks were measured and compared with those of coniferous and dicotyledonous trees. We found that tensile stress existed longitudinally on the surface of vertically growing trunks, whereas compression stress was found at the bending position of leaning trunks. Compression stress was found in the outer part of the central cylinder, whereas tensile stress is generally found in the outer part of the trunk in coniferous and dicotyledonous trees. The distribution of <span class="hlt">strain</span> in the palm trunk is similar to that of compression wood of the leaning trunk of a conifer. Specific gravity was greater in the outer part of the trunk than in the inner part of the trunk. This difference may be related to the distribution of growth stress.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22398929','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22398929"><span>Secretome analysis of Clostridium difficile <span class="hlt">strains</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Boetzkes, Alexander; Felkel, Katharina Wiebke; Zeiser, Johannes; Jochim, Nelli; Just, Ingo; Pich, Andreas</p> <p>2012-08-01</p> <p>Clostridium difficile causes infections ranging from mild C. difficile-associated diarrhea to severe pseudomembranous colitis. Since 2003 new hypervirulent C. difficile <span class="hlt">strains</span> (PCR ribotype 027) emerged characterized by a dramatically increased mortality. The secretomes of the three C. difficile <span class="hlt">strains</span> CDR20291, CD196, and CD630 were analyzed and compared. Proteins were separated and analyzed by means of SDS--PAGE and LC-MS. MS data were analyzed using Mascot and proteins were checked for export signals with SecretomeP and SignalP. LC-MS analysis revealed 158 different proteins in the supernatant of C. difficile. Most of the identified proteins originate from the cytoplasm. Thirty-two proteins in CDR20291, 36 in CD196 and 26 in CD630 were identified to be secreted by C. difficile <span class="hlt">strains</span>. Those were mainly S-layer proteins, substrate-binding proteins of ABC-transporters, cell wall hydrolases, pilin and unknown hypothetical proteins. Toxin A and toxin B were identified after growth in brain heart infusion medium using immunological techniques. The ADP-ribosyltransferase-binding component protein, which is a part of the binary toxin CDT, was only identified in the hypervirulent ribotype 027 <span class="hlt">strains</span>. Further proteins that are secreted specifically by hypervirulent <span class="hlt">strains</span> were identified.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17474617','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17474617"><span>[A prophylactic program for <span class="hlt">strain</span> urinary incontinence].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stadnicka, Grazyna; Iwanowicz-Palus, Grazyna J; Bień, Agnieszka M</p> <p>2002-01-01</p> <p>The aim of the study was to work out a prophylactic program for <span class="hlt">strain</span> urinary incontinence. Analysis of literature on the subject and results of own investigations presented in the first part of the paper indicate that the program of prophylaxis of <span class="hlt">strain</span> urinary incontinence should primarily include: (1) Preparation of the medical staff (nurses, midwives) for propagating health education among women on prevention of <span class="hlt">strain</span> urinary incontinence. (2) Preparation of adequate educational materials in the form of brochures, leaflets, information posters about symptoms, causes and prophylaxis of urinary incontinence indicating health care institutions available to all women when the disease is suspected or already present. (3) Propagation of problems connected with <span class="hlt">strain</span> urinary incontinence in the mass media providing information to a wide audience in order to make people realize the significance of this social problem and break stereotypes associated with this disease of "shame". (4) Preparation of sets of exercises for the muscles of the base of the pelvis to be performed during pregnancy, confinement and menopause to maintain their proper function. (5) Indicating factors predisposing to <span class="hlt">strain</span> urinary incontinence with focus on possibilities of their reduction or elimination.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1015378','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1015378"><span>Brittle superconducting magnets: an equivilent <span class="hlt">strain</span> model</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Barzi, E.; Danuso, M.</p> <p>2010-08-01</p> <p>To exceed fields of 10 T in accelerator magnets, brittle superconductors like A15 Nb{sub 3}Sn and Nb{sub 3}Al or ceramic High Temperature Superconductors have to be used. For such brittle superconductors it is not their maximum tensile yield stress that limits their structural resistance as much as <span class="hlt">strain</span> values that provoke deformations in their delicate lattice, which in turn affect their superconducting properties. Work on the sensitivity of Nb{sub 3}Sn cables to <span class="hlt">strain</span> has been conducted in a number of stress states, including uniaxial and multi-axial, producing usually different results. This has made the need of a constituent design criterion imperative for magnet builders. In conventional structural problems an equivalent stress model is typically used to verify mechanical soundness. In the superconducting community a simple scalar equivalent <span class="hlt">strain</span> to be used in place of an equivalent stress would be an extremely useful tool. As is well known in fundamental mechanics, there is not one single way to reduce a multiaxial <span class="hlt">strain</span> state as represented by a 2nd order tensor to a scalar. The conceptual experiment proposed here will help determine the best scalar representation to use in the identification of an equivalent <span class="hlt">strain</span> model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=261492','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=261492"><span>Comparison of Bacteroides zoogleoformans <span class="hlt">strains</span> isolated from soft tissue infections in cats with <span class="hlt">strains</span> from periodontal disease in humans.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Love, D N; Johnson, J L; Jones, R F; Bailey, M</p> <p>1985-01-01</p> <p>A total of 11 <span class="hlt">strains</span> of Bacteroides zoogleoformans were isolated from 11 of 106 different cat subcutaneous "fight wound" abscesses and were among a total of 143 Bacteroides species isolated from these samples. They constituted 3.4% (11 of 325) of all anaerobic isolates. The cat <span class="hlt">strains</span> and <span class="hlt">strains</span> of B. zoogleoformans isolated from humans with periodontal disease were similar phenotypically as determined by biochemical reactions, polyacrylamide gel electrophoresis patterns of soluble proteins, and guanine plus cytosine ratios of DNA. Eight cat <span class="hlt">strains</span> and five human <span class="hlt">strains</span> tested had 45 to 54% DNA homology with the type <span class="hlt">strain</span> of B. zoogleoformans. The eight cat <span class="hlt">strains</span> and five human <span class="hlt">strains</span> (excluding the type <span class="hlt">strain</span>) were related by DNA homology at 70 to 77%. There was 85 to 90% intragroup DNA homology among the cat <span class="hlt">strains</span> and 86 to 89% intragroup homology among the five human <span class="hlt">strains</span>. The implications for epidemiology and human and animal ecology are discussed. Images PMID:3965393</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22840216','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22840216"><span>Hepatitis E virus <span class="hlt">strains</span> in rabbits and evidence of a closely related <span class="hlt">strain</span> in humans, France.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Izopet, Jacques; Dubois, Martine; Bertagnoli, Stéphane; Lhomme, Sébastien; Marchandeau, Stéphane; Boucher, Samuel; Kamar, Nassim; Abravanel, Florence; Guérin, Jean-Luc</p> <p>2012-08-01</p> <p>Hepatitis E virus (HEV) <span class="hlt">strains</span> from rabbits indicate that these mammals may be a reservoir for HEVs that cause infection in humans. To determine HEV prevalence in rabbits and the <span class="hlt">strains</span>' genetic characteristics, we tested bile, liver, and additional samples from farmed and wild rabbits in France. We detected HEV RNA in 7% (14/200) of bile samples from farmed rabbits (in 2009) and in 23% (47/205) of liver samples from wild rabbits (in 2007-2010). Full-length genomic sequences indicated that all rabbit <span class="hlt">strains</span> belonged to the same clade (nucleotide sequences 72.2%-78.2% identical to HEV genotypes 1-4). Comparison with HEV sequences of human <span class="hlt">strains</span> and reference sequences identified a human <span class="hlt">strain</span> closely related to rabbit <span class="hlt">strain</span> HEV. We found a 93-nt insertion in the X domain of open reading frame 1 of the human <span class="hlt">strain</span> and all rabbit HEV <span class="hlt">strains</span>. These findings indicate that the host range of HEV in Europe is expanding and that zoonotic transmission of HEV from rabbits is possible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4306125','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4306125"><span>MRI-based <span class="hlt">strain</span> and <span class="hlt">strain</span> rate analysis of left ventricle: a modified hierarchical transformation model</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2015-01-01</p> <p>Background Different from other indicators of cardiac function, such as ejection fraction and transmitral early diastolic velocity, myocardial <span class="hlt">strain</span> is promising to capture subtle alterations that result from early diseases of the myocardium. In order to extract the left ventricle (LV) myocardial <span class="hlt">strain</span> and <span class="hlt">strain</span> rate from cardiac cine-MRI, a modified hierarchical transformation model was proposed. Methods A hierarchical transformation model including the global and local LV deformations was employed to analyze the <span class="hlt">strain</span> and <span class="hlt">strain</span> rate of the left ventricle by cine-MRI image registration. The endocardial and epicardial contour information was introduced to enhance the registration accuracy by combining the original hierarchical algorithm with an Iterative Closest Points using Invariant Features algorithm. The hierarchical model was validated by a normal volunteer first and then applied to two clinical cases (i.e., the normal volunteer and a diabetic patient) to evaluate their respective function. Results Based on the two clinical cases, by comparing the displacement fields of two selected landmarks in the normal volunteer, the proposed method showed a better performance than the original or unmodified model. Meanwhile, the comparison of the radial <span class="hlt">strain</span> between the volunteer and patient demonstrated their apparent functional difference. Conclusions The present method could be used to estimate the LV myocardial <span class="hlt">strain</span> and <span class="hlt">strain</span> rate during a cardiac cycle and thus to quantify the analysis of the LV motion function. PMID:25602778</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19830024945','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19830024945"><span>Effect of <span class="hlt">strain</span> isolator pad modulus on inplane <span class="hlt">strain</span> in Shuttle Orbiter thermal protection system tiles</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sawyer, J. W.</p> <p>1983-01-01</p> <p>The thermal protection system used on the Space Shuttle orbiter to determine <span class="hlt">strains</span> in the reusable surface insulation tiles under simulated flight loads was investigated. The effects of changes in the <span class="hlt">strain</span> isolator pad (SIP) moduli on the <span class="hlt">strains</span> in the tile were evaluated. To analyze the SIP/tile system, it was necessary to conduct tests to determine inplane tension and compression modulus and inplane failure <span class="hlt">strain</span> for the densified layer of the tiles. It is shown that densification of the LI-900 tile material increases the modulus by a factor of 6 to 10 and reduces the failure <span class="hlt">strain</span> by about 50%. It is indicated that the inplane <span class="hlt">strain</span> levels in the Shuttle tiles in the highly loaded regions are approximately 2 orders of magnitude lower than the failure <span class="hlt">strain</span> of the material. It is concluded that most of the LI-900 tiles on the Shuttle could be mounted on a SIP with tensile and shear stiffnesses 10 times those of the present SIP without inplane <span class="hlt">strain</span> failure in the tile.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015CPL...625...69R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015CPL...625...69R"><span><span class="hlt">Strain</span> in <span class="hlt">strain</span>-free benzenoid hydrocarbons: The case of phenanthrene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Radenković, Slavko; Gutman, Ivan; Đorđević, Slađana</p> <p>2015-04-01</p> <p>Benzenoid molecules possessing bays are traditionally considered as '<span class="hlt">strain</span>-free'. Yet, repulsion between the two bay H-atoms affects the length of the near-lying carbon-carbon bonds. A method is developed to estimate the energy of this <span class="hlt">strain</span>. In the case of phenanthrene its value was found to be about 7 kJ/mol.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24978749','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24978749"><span><span class="hlt">Strain</span> dependence of the nonlinear optical properties of <span class="hlt">strained</span> Si nanoparticles.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dhara, Soumen; Imakita, Kenji; Giri, P K; Fujii, Minoru</p> <p>2014-07-01</p> <p>We report on the lattice <span class="hlt">strain</span> dependence of the nonlinear optical (NLO) parameters of <span class="hlt">strained</span> Si nanoparticles (NPs), which are prepared in a controlled way by a mechanical ball milling process. X-ray diffraction analysis shows that the nature of <span class="hlt">strain</span> is compressive and is primarily caused by milling-induced lattice dislocations, which is further supported by high-resolution transmission electron microscopy imaging. It is found that the nonlinear refractive index (n₂) and nonlinear absorption coefficient (β) are strongly influenced by the associated lattice <span class="hlt">strain</span> present in Si NPs. With the increase of lattice <span class="hlt">strain</span>, the β gradually decreases while n₂ increases slowly. The <span class="hlt">strain</span>-dependent observed changes in the NLO parameters of Si NPs are found to be advantageous for application purpose, and it is explained on the basis of <span class="hlt">strain</span>-induced modification in the electronic structure of the highest occupied molecular orbital and lowest unoccupied molecular orbital states of Si NPs. These results demonstrate the potential of <span class="hlt">strain</span>-dependent enhancement of nonlinearities for silicon photonics applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27585446','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27585446"><span>Computer modelling of bone's adaptation: the role of normal <span class="hlt">strain</span>, shear <span class="hlt">strain</span> and fluid flow.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tiwari, Abhishek Kumar; Prasad, Jitendra</p> <p>2017-04-01</p> <p>Bone loss is a serious health problem. In vivo studies have found that mechanical stimulation may inhibit bone loss as elevated <span class="hlt">strain</span> in bone induces osteogenesis, i.e. new bone formation. However, the exact relationship between mechanical environment and osteogenesis is less clear. Normal <span class="hlt">strain</span> is considered as a prime stimulus of osteogenic activity; however, there are some instances in the literature where osteogenesis is observed in the vicinity of minimal normal <span class="hlt">strain</span>, specifically near the neutral axis of bending in long bones. It suggests that osteogenesis may also be induced by other or secondary components of mechanical environment such as shear <span class="hlt">strain</span> or canalicular fluid flow. As it is evident from the literature, shear <span class="hlt">strain</span> and fluid flow can be potent stimuli of osteogenesis. This study presents a computational model to investigate the roles of these stimuli in bone adaptation. The model assumes that bone formation rate is roughly proportional to the normal, shear and fluid shear <span class="hlt">strain</span> energy density above their osteogenic thresholds. In vivo osteogenesis due to cyclic cantilever bending of a murine tibia has been simulated. The model predicts results close to experimental findings when normal <span class="hlt">strain</span>, and shear <span class="hlt">strain</span> or fluid shear were combined. This study also gives a new perspective on the relation between osteogenic potential of micro-level fluid shear and that of macro-level bending shear. Attempts to establish such relations among the components of mechanical environment and corresponding osteogenesis may ultimately aid in the development of effective approaches to mitigating bone loss.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850007898','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850007898"><span>Measurement of high temperature <span class="hlt">strain</span> by the laser-speckle <span class="hlt">strain</span> gauge</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Yamaguchi, I.</p> <p>1984-01-01</p> <p>By using the laser-speckle <span class="hlt">strain</span> gauge, the <span class="hlt">strain</span> of metal at the temperature lower than 250 C is measured. The principle of the gauge is to measure the expansion or contraction of the fine structures of surface by detecting the resultant speckle displacement in an optoelectronic way, whereby the effect of rigid-body motion is automatically cancelled out with the aid of a differential detection system. A transportable apparatus was built and a comparison experiment performed with a resistance <span class="hlt">strain</span> gauge at room temperature. It has a <span class="hlt">strain</span> sensitivity of .00002, a gauge length smaller than 1 mm, and no upper limit in a range of <span class="hlt">strain</span> measurement. In the measurement of high-temperature <span class="hlt">strain</span> it is free from the need for a dummy gauge and insensitive to an electric drift effect. As examples of <span class="hlt">strain</span> measurement at high-temperature, thermal expansion and contraction of a top of a soldering iron are measured. The interval of the measurement can be made at shortest 1.6 sec. and the change in the <span class="hlt">strain</span> is clearly followed until the ultimate stationary temperature is reached.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SMaS...25j5008X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SMaS...25j5008X"><span>High sensitivity knitted fabric <span class="hlt">strain</span> sensors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xie, Juan; Long, Hairu; Miao, Menghe</p> <p>2016-10-01</p> <p>Wearable sensors are increasingly used in smart garments for detecting and transferring vital signals and body posture, movement and respiration. Existing fabric <span class="hlt">strain</span> sensors made from metallized yarns have low sensitivity, poor comfort and low durability to washing. Here we report a knitted fabric <span class="hlt">strain</span> sensor made from a cotton/stainless steel (SS) fibre blended yarn which shows much higher sensitivity than sensors knitted from metallized yarns. The fabric feels softer than pure cotton textiles owing to the ultrafine stainless steel fibres and does not lose its electrical property after washing. The reason for the high sensitivity of the cotton/SS knitted fabric sensor was explored by comparing its sensing mechanism with the knitted fabric sensor made from metallized yarns. The results show that the cotton/SS yarn-to-yarn contact resistance is highly sensitive to <span class="hlt">strain</span> applied to hooked yarn loops.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21666210','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21666210"><span>Genetic characterization of measles vaccine <span class="hlt">strains</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bankamp, Bettina; Takeda, Makoto; Zhang, Yan; Xu, Wenbo; Rota, Paul A</p> <p>2011-07-01</p> <p>The complete genomic sequences of 9 measles vaccine <span class="hlt">strains</span> were compared with the sequence of the Edmonston wild-type virus. AIK-C, Moraten, Rubeovax, Schwarz, and Zagreb are vaccine <span class="hlt">strains</span> of the Edmonston lineage, whereas CAM-70, Changchun-47, Leningrad-4 and Shanghai-191 were derived from 4 different wild-type isolates. Nucleotide substitutions were found in the noncoding regions of the genomes as well as in all coding regions, leading to deduced amino acid substitutions in all 8 viral proteins. Although the precise mechanisms involved in the attenuation of individual measles vaccines remain to be elucidated, in vitro assays of viral protein functions and recombinant viruses with defined genetic modifications have been used to characterize the differences between vaccine and wild-type <span class="hlt">strains</span>. Although almost every protein contributes to an attenuated phenotype, substitutions affecting host cell tropism, virus assembly, and the ability to inhibit cellular antiviral defense mechanisms play an especially important role in attenuation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19940036325&hterms=bethel&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dbethel','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19940036325&hterms=bethel&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dbethel"><span>A photoelastic fiber optic <span class="hlt">strain</span> gage</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Su, Wei; Gilbert, John A.; Katsunis, Constantine</p> <p>1992-01-01</p> <p>This paper reports on the development of a photoelastic fiber optic <span class="hlt">strain</span> gage sensitive to transverse <span class="hlt">strain</span>. The sensing element is made from an epoxy resin which is stress frozen to passively achieve the quadrature condition. Light, emitted from an LED operating at 820 nm, is transmitted to and from the sensing element via multimode fibers and the signal is detected using a dual channel operational photodiode/amplifier. This unique combination of optics and electronics produces a fiber optic sensor having a high signal to noise ratio which is lead-in/out insensitive. Results show that <span class="hlt">strains</span> on the order of 1 microstrain can be measured over an 800 microstrain range and that dummy gages can be used for temperature compensation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16178463','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16178463"><span>[Deoxyribonuclease activity detection in Clostridium chauvoei <span class="hlt">strains</span>].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Carloni, G H; Bentancor, L D; De Torres, R A</p> <p>2005-01-01</p> <p>Beta toxin of C. chauvoei has desoxiribonuclease (DNase) activity which is regarded as one of its virulence factors. The production of DNase was detected in <span class="hlt">strains</span> isolated from bovines, using as controls C. chauvoei ATCC 10092, and C. perfringens Type A and C. septicum, both laboratory isolates. The enzyme activity was made evident on a DNA substrate observing the macroscopic degradation. A simple methodology was developed using a commercial medium for DNase test, with the incorporation of sterile horse serum. Each <span class="hlt">strain</span> was streaked on the surface of the medium, incubated in anaerobic atmosphere at 37 degrees C for 48 hours. The plates were revealed with HCI 1 N. The appearance of a clear and transparent zone around and under the microbial growing was considered a positive reaction. Enzyme activity was detected in 10 of 12 <span class="hlt">strains</span> and also in the controls. The serum addition to the commercial basal medium allows the optimum development of the microorganism showing the enzymatic digestion zone.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150000844','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150000844"><span>Wing Shape Sensing from Measured <span class="hlt">Strain</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pak, Chan-Gi</p> <p>2015-01-01</p> <p>A new two step theory is investigated for predicting the deflection and slope of an entire structure using <span class="hlt">strain</span> measurements at discrete locations. In the first step, a measured <span class="hlt">strain</span> is fitted using a piecewise least squares curve fitting method together with the cubic spline technique. These fitted <span class="hlt">strains</span> are integrated twice to obtain deflection data along the fibers. In the second step, computed deflection along the fibers are combined with a finite element model of the structure in order to extrapolate the deflection and slope of the entire structure through the use of System Equivalent Reduction and Expansion Process. The theory is first validated on a computational model, a cantilevered rectangular wing. It is then applied to test data from a cantilevered swept wing model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JSemi..38e3003K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JSemi..38e3003K"><span>MWCNTs based flexible and stretchable <span class="hlt">strain</span> sensors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Khan, Saeed Ahmed; Gao, Min; Zhu, Yuechang; Yan, Zhuocheng; Lin, Yuan</p> <p>2017-06-01</p> <p>Carbon nanotubes have potential applications in flexible and stretchable devices due to their remarkable electromechanical properties. Flexible and stretchable <span class="hlt">strain</span> sensors of multi-walled carbon nanotubes (MWCNTs) with aligned or random structures were fabricated on poly-dimethylsiloxane (PDMS) substrate with different techniques. It was observed that the spraycoatedtechniquebased <span class="hlt">strain</span> sensor fabricated on PDMS substrate showed higher sensitivity higher stretchability, better linearity and excellent longer time stability than the sensor fabricated with other methods presented in this work. The scanning electron microscopy images indicated the spray coating technique can produce a better uniform and compact CNT network, which is the important role affecting the performance of CNT-based flexible <span class="hlt">strain</span> sensors. Project supported by the National Basic Research Program of China (No. 2015CB351905), the National Natural Science Foundation of China (No. 61306015), the Technology Innovative Research Team of Sichuan Province of China (No.2015TD0005), and “111” Project (No. B13042)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26424643','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26424643"><span>Epstein-Barr Virus <span class="hlt">Strain</span> Variation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Farrell, Paul J</p> <p>2015-01-01</p> <p>What is wild-type Epstein-Barr virus and are there genetic differences in EBV <span class="hlt">strains</span> that contribute to some of the EBV-associated diseases? Recent progress in DNA sequencing has resulted in many new Epstein-Barr virus (EBV) genome sequences becoming available. EBV isolates worldwide can be grouped into type 1 and type 2, a classification based on the EBNA2 gene sequence. Type 1 transforms human B cells into lymphoblastoid cell lines much more efficiently than type 2 EBV and molecular mechanisms that may account for this difference in cell transformation are now becoming understood. Study of geographic variation of EBV <span class="hlt">strains</span> independent of the type 1/type 2 classification and systematic investigation of the relationship between viral <span class="hlt">strains</span>, infection and disease are now becoming possible. So we should consider more directly whether viral sequence variation might play a role in the incidence of some EBV-associated diseases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11712610','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11712610"><span>Conservative treatment for repetitive <span class="hlt">strain</span> injury.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Konijnenberg, H S; de Wilde, N S; Gerritsen, A A; van Tulder, M W; de Vet, H C</p> <p>2001-10-01</p> <p>Various conservative treatment options for repetitive <span class="hlt">strain</span> injury are widely used, despite questionable evidence of their effectiveness. This systematic review evaluates the effectiveness of these treatment options for relieving symptoms of repetitive <span class="hlt">strain</span> injury and improving activities of daily living. Searches in Medline and Embase, with additional reference checking resulted in 15 eligible trials for this review. Methodological quality was assessed, and data-extraction was performed. With the use of a "best-evidence synthesis", no strong evidence was found for the effectiveness of any of the treatment options. There is limited evidence that multidisciplinary rehabilitation, ergonomic intervention measures, exercises, and spinal manipulation combined with soft tissue therapy are effective in providing symptom relief or improving activities of daily living. There is conflicting evidence for the effectiveness of behavioral therapy. In conclusion, little is known about the effectiveness of conservative treatment options for repetitive <span class="hlt">strain</span> injury. To establish strong evidence, more high-quality trials are needed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=246638','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=246638"><span>Dialysis Culture of T-<span class="hlt">Strain</span> Mycoplasmas</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Masover, Gerald K.; Hayflick, Leonard</p> <p>1974-01-01</p> <p>Using dialyzing cultures of T-<span class="hlt">strain</span> mycoplasmas, it was possible to make some observations relevant to the growth and metabolism of these organisms which would not be possible in nondialyzing cultures due to growth inhibition of the organisms by elevated pH and increased ammonium ion concentration in media containing urea. The rate of ammonia accumulation was found to be related to the initial urea concentration in the medium and could not be accounted for by any change in the multiplication rate of the organisms. More ammonia was generated than could be accounted for by the added urea alone, suggesting that an ammonia-producing activity other than urease may be present in T-<span class="hlt">strain</span> mycoplasmas. Titers above 107 color change units per ml were achieved in dialysis cultures of a T-<span class="hlt">strain</span> mycoplasma in the presence of urea, and such titers were maintained for approximately 60 h during dialysis culture in the absence of added urea. PMID:4595203</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4286197','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4286197"><span>Genome sequence of Coxiella burnetii <span class="hlt">strain</span> Namibia</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2014-01-01</p> <p>We present the whole genome sequence and annotation of the Coxiella burnetii <span class="hlt">strain</span> Namibia. This <span class="hlt">strain</span> was isolated from an aborting goat in 1991 in Windhoek, Namibia. The plasmid type QpRS was confirmed in our work. Further genomic typing placed the <span class="hlt">strain</span> into a unique genomic group. The genome sequence is 2,101,438 bp long and contains 1,979 protein-coding and 51 RNA genes, including one rRNA operon. To overcome the poor yield from cell culture systems, an additional DNA enrichment with whole genome amplification (WGA) methods was applied. We describe a bioinformatics pipeline for improved genome assembly including several filters with a special focus on WGA characteristics. PMID:25593636</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26446292','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26446292"><span>Realization of a <span class="hlt">Strained</span> Atomic Wire Superlattice.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Song, Inkyung; Goh, Jung Suk; Lee, Sung-Hoon; Jung, Sung Won; Shin, Jin Sung; Yamane, Hiroyuki; Kosugi, Nobuhiro; Yeom, Han Woong</p> <p>2015-11-24</p> <p>A superlattice of <span class="hlt">strained</span> Au-Si atomic wires is successfully fabricated on a Si surface. Au atoms are known to incorporate into the stepped Si(111) surface to form a Au-Si atomic wire array with both one-dimensional (1D) metallic and antiferromagnetic atomic chains. At a reduced density of Au, we find a regular array of Au-Si wires in alternation with pristine Si nanoterraces. Pristine Si nanoterraces impose a <span class="hlt">strain</span> on the neighboring Au-Si wires, which modifies both the band structure of metallic chains and the magnetic property of spin chains. This is an ultimate 1D version of a <span class="hlt">strained</span>-layer superlattice of semiconductors, defining a direction toward the fine engineering of self-assembled atomic-scale wires.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..MAR.F4002B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..MAR.F4002B"><span>Diffraction Correlation to Reconstruct Highly <span class="hlt">Strained</span> Particles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brown, Douglas; Harder, Ross; Clark, Jesse; Kim, J. W.; Kiefer, Boris; Fullerton, Eric; Shpyrko, Oleg; Fohtung, Edwin</p> <p>2015-03-01</p> <p>Through the use of coherent x-ray diffraction a three-dimensional diffraction pattern of a highly <span class="hlt">strained</span> nano-crystal can be recorded in reciprocal space by a detector. Only the intensities are recorded, resulting in a loss of the complex phase. The recorded diffraction pattern therefore requires computational processing to reconstruct the density and complex distribution of the diffracted nano-crystal. For highly <span class="hlt">strained</span> crystals, standard methods using HIO and ER algorithms are no longer sufficient to reconstruct the diffraction pattern. Our solution is to correlate the symmetry in reciprocal space to generate an a priori shape constraint to guide the computational reconstruction of the diffraction pattern. This approach has improved the ability to accurately reconstruct highly <span class="hlt">strained</span> nano-crystals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3586687','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3586687"><span>Convergent Replication of Mouse Synthetic Prion <span class="hlt">Strains</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ghaemmaghami, Sina; Colby, David W.; Nguyen, Hoang-Oanh B.; Hayashi, Shigenari; Oehler, Abby; DeArmond, Stephen J.; Prusiner, Stanley B.</p> <p>2014-01-01</p> <p>Prion diseases are neurodegenerative disorders characterized by the aberrant folding of endogenous proteins into self-propagating pathogenic conformers. Prion disease can be initiated in animal models by inoculation with amyloid fibrils formed from bacterially derived recombinant prion protein. The synthetic prions that accumulated in infected organisms are structurally distinct from the amyloid preparations used to initiate their formation and change conformationally on repeated passage. To investigate the nature of synthetic prion transformation, we infected mice with a conformationally diverse set of amyloids and serially passaged the resulting prion <span class="hlt">strains</span>. At each passage, we monitored changes in the biochemical and biological properties of the adapting <span class="hlt">strain</span>. The physicochemical properties of each synthetic prion <span class="hlt">strain</span> gradually changed on serial propagation until attaining a common adapted state with shared physicochemical characteristics. These results indicate that synthetic prions can assume multiple intermediate conformations before converging into one conformation optimized for in vivo propagation. PMID:23438476</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19777804','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19777804"><span>[Novel methods and strategies for <span class="hlt">strain</span> improvement].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhao, Wenting; Zou, Yi; Hu, Changhua</p> <p>2009-06-01</p> <p>Improvement of the productivity of industrial <span class="hlt">strains</span> is an important field in micro-biology, because wild-type <span class="hlt">strains</span> isolated from nature usually produce only a low level of antibiotics. Although random screening and simple rational screening are still effective without using genomic information, they are always time- and labor-consuming. With the broad application of recombinant DNA technology, protoplast fusion and X-omics, novel methods and strategies such as metabolic engineering, genome shuffling, system biology and system biotechnology, ribosome engineering, epigenetic modification are being exploited for the industry microbiology. In this review, we will focus on the progress of these novel methods and strategies for <span class="hlt">strain</span> improvement in recent years.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6217136','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6217136"><span>Glycerol production of various <span class="hlt">strains</span> of saccharomyces</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Radler, F.; Schuetz, H.</p> <p>1982-01-01</p> <p>The quantity of glycerol as principal by-product of the alcoholic fermentation depends to a large extent on the yeast <span class="hlt">strain</span>. Different <span class="hlt">strains</span> of Saccharomyces cerevisiae were found to form amounts of glycerol varying between 4.2 to 10.4 g/L. The formation of glycerol is regarded as a result of the competition between alcohol dehydrogenase and glycerol-3-phosphate dehydrogenase that compete for the reduced coenzyme NADH/sub 2/. High and low glycerol forming yeast <span class="hlt">strains</span> showed large differences in the activity of glycerol-3-phosphate dehydrogenase and only small variation in the activity of alcohol dehydrogenase. The total amount of glycerol formed was also influenced by amino acids. In thiamine deficient media a decrease in glycerol formation was observed. Experiments indicate a correlation between the formation of acetaldehyde and glycerol and the production of cell mass that may be of practical interest. (Refs. 12).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11899471','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11899471"><span>Yeast <span class="hlt">strains</span> from Livingston Island, Antarctica.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pavlova, K; Grigorova, D; Hristozova, T; Angelov, A</p> <p>2001-01-01</p> <p>Five yeast <span class="hlt">strains</span> were isolated from soil and moss samples from the Livingston Island (Antarctica) and identified according to morphological cultural and physiological characteristics. All <span class="hlt">strains</span> had an optimum growth temperature of 15 degrees C: none grew above 25 degrees C. They assimilated D-glucose, D-galactose, sucrose, cellobiose, trehalose, 2-keto-D-gluconate, D-xylose, D-ribose and melezitose. Four of them were nonfermentative, only one, which formed pseudomycelium fermented glucose, galactose, trehalose. Two <span class="hlt">strains</span> were identified as pink-red yeasts belonging to genus Rhodotorula--R. minuta and R. mucilaginosa; two were related to the genus Cryptococcus--C. albidus and C. laurentii; one was Candida oleophila.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1981RScI...52.1417R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1981RScI...52.1417R"><span>Simple and sensitive <span class="hlt">strain</span> gauge displacement transducer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ramana, Y. V.; Sarma, L. P.</p> <p>1981-09-01</p> <p>We describe a simple and sensitive <span class="hlt">strain</span> gauge displacement transducer. It is based on the linear movement of a shaft (with two cantilevers and four <span class="hlt">strain</span> gauges) in a tapered chamber, resulting in a change in resistance proportional to the cantilever deformation. The transducer with its Wheatstone full bridge configuration is calibrated against a mechanical dial indicator of 0.002 mm accuracy for both ac and dc voltage excitations. Its output is linear for measurements of full range displacement up to 25 mm. It has a sensitivity of ±0.0082 mm for ac excitation with a <span class="hlt">strain</span> indicator whose resolution is ±1 μɛ. It has a dc full range sensitivity of 1.5 mV/V for excitation levels up to 5 V. It can have varied field and laboratory applications wherever displacements are precisely read, recorded, or monitored.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/956356','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/956356"><span>The breaking <span class="hlt">strain</span> of neutron star crust</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kadau, Kai; Horowitz, C J</p> <p>2009-01-01</p> <p>Mountains on rapidly rotating neutron stars efficiently radiate gravitational waves. The maximum possible size of these mountains depends on the breaking <span class="hlt">strain</span> of neutron star crust. With multimillion ion molecular dynamics simulations of Coulomb solids representing the crust, we show that the breaking <span class="hlt">strain</span> of pure single crystals is very large and that impurities, defects, and grain boundaries only modestly reduce the breaking <span class="hlt">strain</span> to around 0.1. Due to the collective behavior of the ions during failure found in our simulations, the neutron star crust is likely very strong and can support mountains large enough so that their gTavitational wave radiation could limit the spin periods of some stars and might be detectable in large scale interferometers. Furthermore, our microscopic modeling of neutron star crust material can help analyze mechanisms relevant in Magnetar Giant and Micro Flares.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950022297','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950022297"><span>Test load verification through <span class="hlt">strain</span> data analysis</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Verderaime, V.; Harrington, F.</p> <p>1995-01-01</p> <p>A traditional binding acceptance criterion on polycrystalline structures is the experimental verification of the ultimate factor of safety. At fracture, the induced <span class="hlt">strain</span> is inelastic and about an order-of-magnitude greater than designed for maximum expected operational limit. At this extreme <span class="hlt">strained</span> condition, the structure may rotate and displace at the applied verification load such as to unknowingly distort the load transfer into the static test article. Test may result in erroneously accepting a submarginal design or rejecting a reliable one. A technique was developed to identify, monitor, and assess the load transmission error through two back-to-back surface-measured <span class="hlt">strain</span> data. The technique is programmed for expediency and convenience. Though the method was developed to support affordable aerostructures, the method is also applicable for most high-performance air and surface transportation structural systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/9531071','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/9531071"><span>Two nosocomial <span class="hlt">strains</span> of Stenotrophomonas maltophilia transferring antibiotic resistance to Proteus mirabilis P-38 recipient <span class="hlt">strain</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Blahová, J; Králiková, K; Krcméry, V; Chmelarová, E; Torsová, V</p> <p>1998-02-01</p> <p>In this report we describe a specific transfer of carbenicillin and cephaloridine resistance determinants from two different <span class="hlt">strains</span> of Stenotrophomonas maltophilia: No. 215 and 221 isolated from two critically ill patients treated in different Intensive Care Units of a large University Hospital in Ostrava, Czech Republic. These <span class="hlt">strains</span> were resistant to flouroquinolones and the following beta-lactam drugs: carbenicillin, cephaloridine, cefotaxime, ceftazidime, cefepime, imipenem, meropenem and aztreonam. Both <span class="hlt">strains</span> transferred carbenicillin and cephaloridine resistance determinants, with rather different frequency, to Proteus mirabilis P-38. All carbenicillin-selected transconjugants were found by an indirect selection method to be co-resistant to cephaloridine only. In a second cycle of transfers Proteus mirabilis R+ <span class="hlt">strains</span> directly transferred carbenicillin and cephalothin determinants to Escherichia coli K-12 No. 185 nal+ lac+ recipient <span class="hlt">strain</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ChPhB..24c6801S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ChPhB..24c6801S"><span><span class="hlt">Strain</span> analysis of free-standing <span class="hlt">strained</span> silicon-on-insulator nanomembrane</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sun, Gao-Di; Dong, Lin-Xi; Xue, Zhong-Ying; Chen, Da; Guo, Qing-Lei; Mu, Zhi-Qiang</p> <p>2015-03-01</p> <p>Based on the ultra-thin <span class="hlt">strained</span> silicon-on-insulator (sSOI) technology, by creatively using a hydrofluoric acid (HF) vapor corrosion system to dry etch the SiO2 layer, a large area of suspended <span class="hlt">strained</span> silicon (sSi) nanomembrane with uniform <span class="hlt">strain</span> distribution is fabricated. The <span class="hlt">strain</span> state in the implemented nanomembrane is comprehensively analyzed by using an UV-Raman spectrometer with different laser powers. The results show that the inherent <span class="hlt">strain</span> is preserved while there are artificial Raman shifts induced by the heat effect, which is proportional to the laser power. The suspended sSOI nanomembrane will be an important material for future novel high-performance devices. Project supported by the National Natural Science Foundation of China (Grant Nos. 61376117 and 61107025) and the Zhejiang Provincial Natural Science Foundation of China (Grant No. LY13F040004).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880012129','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880012129"><span>Controlled-<span class="hlt">strain</span> rate tests at very low <span class="hlt">strain</span> rates of 2618 aluminum at 200 C</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ding, J. L.; Lee, S. R.</p> <p>1988-01-01</p> <p>Constant <span class="hlt">strain</span> rate tests and constant load creep tests were performed on 2618 aluminum at 200 C. The <span class="hlt">strain</span> rates used in the constant <span class="hlt">strain</span> rate tests were 10 to the minus 6, 10 to the minus 7, 10 to the minum 8, and 10 to the minus 9/sec. Due to the fact that the <span class="hlt">strain</span> rates in both tests were comparable to each other, the similarities between them can therefore be studied. It was concluded that metals are essentially rate sensitive at elevated temperatures. The traditional definition of creep and plasticity used in the classical creep analysis is actually a reflection of the material behavior under different loading conditions. A constitutive equation based on the test data under one loading condition should work well for other loading conditions as long as the <span class="hlt">strain</span> rates are in the same range as those under which the material constants are determined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997SPIE.3054..118R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997SPIE.3054..118R"><span>Measurement of local values of <span class="hlt">strains</span> of the briquette by means of special resistance <span class="hlt">strain</span> gauges</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rysz, Jozef</p> <p>1997-02-01</p> <p>Local measurement of the coal briquette <span class="hlt">strains</span> during its destruction caused by sudden decrease of pressure of gas filling pores is difficult, because of high <span class="hlt">strain</span> of coal (exceeds 16%), which results in bursting. A special type of an resistance-<span class="hlt">strain</span> gauge, which is pressed into a defined position during briquette preparation was elaborated. This gauge is deformed just as the surrounding coal. The <span class="hlt">strain</span> is measured as a difference in resistance of a mixture of coal grains (briquette material) and short, 8 micrometers dia. graphite fibers. A ca. 0.5 mm thick and ca. 1 mm long gauge was prepared. Its initial resistance constituted several hundreds ohms. The resistance vs. <span class="hlt">strain</span> dependence is not linear but stable enough in time and does not depend on the type of gas filling briquette pores (e.g. CO2 and He).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28068587','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28068587"><span>Quantitative assessment of viable cells of Lactobacillus plantarum <span class="hlt">strains</span> in single, dual and multi-<span class="hlt">strain</span> biofilms.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fernández Ramírez, Mónica D; Kostopoulos, Ioannis; Smid, Eddy J; Nierop Groot, Masja N; Abee, Tjakko</p> <p>2017-03-06</p> <p>Biofilms of Lactobacillus plantarum are a potential source for contamination and recontamination of food products. Although biofilms have been mostly studied using single species or even single <span class="hlt">strains</span>, it is conceivable that in a range of environmental settings including food processing areas, biofilms are composed of multiple species with each species represented by multiple <span class="hlt">strains</span>. In this study six spoilage related L. plantarum <span class="hlt">strains</span> FBR1-FBR6 and the model <span class="hlt">strain</span> L. plantarum WCFS1 were characterised in single, dual and multiple <span class="hlt">strain</span> competition models. A quantitative PCR approach was used with added propidium monoazide (PMA) enabling quantification of intact cells in the biofilm, representing the viable cell fraction that determines the food spoilage risk. Our results show that the performance of individual <span class="hlt">strains</span> in multi-<span class="hlt">strain</span> cultures generally correlates with their performance in pure culture, and relative <span class="hlt">strain</span> abundance in multi-<span class="hlt">strain</span> biofilms positively correlated with the relative <span class="hlt">strain</span> abundance in suspended (planktonic) cultures. Performance of individual <span class="hlt">strains</span> in dual-<span class="hlt">strain</span> biofilms was highly influenced by the presence of the secondary <span class="hlt">strain</span>, and in most cases no correlation between the relative contributions of viable planktonic cells and viable cells in the biofilm was noted. The total biofilm quantified by CV staining of the dual and multi-<span class="hlt">strain</span> biofilms formed was mainly correlated to CV values of the dominant <span class="hlt">strain</span> obtained in single <span class="hlt">strain</span> studies. However, the combination of <span class="hlt">strain</span> FBR5 and <span class="hlt">strain</span> WCFS1 showed significantly higher CV values compared to the individual performances of both <span class="hlt">strains</span> indicating that total biofilm formation was higher in this specific condition. Notably, L. plantarum FBR5 was able to outgrow all other <span class="hlt">strains</span> and showed the highest relative abundance in dual and multi-<span class="hlt">strain</span> biofilms. All the dual and multi-<span class="hlt">strain</span> biofilms contained a considerable number of viable cells, representing a potential</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20375237','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20375237"><span>Cyclomodulins in urosepsis <span class="hlt">strains</span> of Escherichia coli.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dubois, Damien; Delmas, Julien; Cady, Anne; Robin, Frédéric; Sivignon, Adeline; Oswald, Eric; Bonnet, Richard</p> <p>2010-06-01</p> <p>Determinants of urosepsis in Escherichia coli remain incompletely defined. Cyclomodulins (CMs) are a growing functional family of toxins that hijack the eukaryotic cell cycle. Four cyclomodulin types are actually known in E. coli: cytotoxic necrotizing factors (CNFs), cycle-inhibiting factor (Cif), cytolethal distending toxins (CDTs), and the pks-encoded toxin. In the present study, the distribution of CM-encoding genes and the functionality of these toxins were investigated in 197 E. coli <span class="hlt">strains</span> isolated from patients with community-acquired urosepsis (n = 146) and from uninfected subjects (n = 51). This distribution was analyzed in relation to the phylogenetic background, clinical origin, and antibiotic resistance of the <span class="hlt">strains</span>. It emerged from this study that <span class="hlt">strains</span> harboring the pks island and the cnf1 gene (i) were strongly associated with the B2 phylogroup (P, <0.001), (ii) frequently harbored both toxin-encoded genes in phylogroup B2 (33%), and (iii) were predictive of a urosepsis origin (P, <0.001 to 0.005). However, the prevalences of the pks island among phylogroup B2 <span class="hlt">strains</span>, in contrast to those of the cnf1 gene, were not significantly different between fecal and urosepsis groups, suggesting that the pks island is more important for the colonization process and the cnf1 gene for virulence. pks- or cnf1-harboring <span class="hlt">strains</span> were significantly associated with susceptibility to antibiotics (amoxicillin, cotrimoxazole, and quinolones [P, <0.001 to 0.043]). Otherwise, only 6% and 1% of all <span class="hlt">strains</span> harbored the cdtB and cif genes, respectively, with no particular distribution by phylogenetic background, antimicrobial susceptibility, or clinical origin.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17832524','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17832524"><span>Episodic <span class="hlt">strain</span> accumulation in southern california.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Thatcher, W</p> <p>1976-11-12</p> <p>Reexamination of horizontal geodetic data in the region of recently discovered aseismic uplift has demonstrated that equally unusual horizontal crustal deformation accompanied the development of the uplift. During this time interval compressive <span class="hlt">strains</span> were oriented roughly normal to the San Andreas fault, suggesting that the uplift produced little shear <span class="hlt">strain</span> accumulation across this fault. On the other hand, the orientation of the anomalous shear <span class="hlt">straining</span> is consistent with <span class="hlt">strain</span> accumulation across northdipping range-front thrusts like the San Fernando fault. Accordingly, the horizontal and vertical crustal deformation disclosed by geodetic observation is interpreted as a short epoch of rapid <span class="hlt">strain</span> accumulation on these frontal faults. If this interpretation is correct, thrust-type earthquakes will eventually release the accumulated <span class="hlt">strains</span>, but the geodetic data examined here cannot be used to estimate when these events might occur. However, observation of an unusual sequence of tilts prior to 1971 on a level line lying to the north of the magnitude 6.4 San Fernando earthquake offers some promise for precursor monitoring. The data are adequately explained by a simple model of up-dip aseismic slip propagation toward the 1971 epicentral region. These observations and the simple model that accounts for them suggest a conceptually straightforward monitoring scheme to search for similar uplift and tilt precursors within the uplifted region. Such premonitory effects could be detected by a combination of frequenlty repeated short (30 to 70 km in length) level line measurements, precise gravity traverses, and continuously recording gravimeters sited to the north of the active frontal thrust faults. Once identified, such precursors could be closely followed in space and time, and might then provide effective warnings of impending potentially destructive earth-quakes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003SPIE.5055..319C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003SPIE.5055..319C"><span><span class="hlt">Strain</span> energy harvesting for wireless sensor networks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Churchill, David L.; Hamel, Michael J.; Townsend, Christopher P.; Arms, Steven W.</p> <p>2003-07-01</p> <p>Our goal was to demonstrate a robust <span class="hlt">strain</span> energy harvesting system for powering an embedded wireless sensor network without batteries. A composite material specimen was laminated with unidirectional aligned piezoelectric fibers (PZT5A, 250 um, overall 13x10x.38 mm). The fibers were embedded within a resin matrix for damage tolerance (Advanced Cerametrics, Lambertville, NJ). A foil <span class="hlt">strain</span> gauge (Micro-Measurements, Raleigh, NC) was bonded to the piezoelectric fiber and shunt calibrated. The specimen was loaded in three point cyclic bending (75 to 300 μɛ peak) using an electrodynamic actuator operating at 60,120, and 180 Hz. <span class="hlt">Strain</span> energy was stored by rectifying piezoelectric fiber output into a capacitor bank. When the capacitor voltage reached a preset threshold, charge was transferred to an integrated, embeddable wireless sensor node (<span class="hlt">Strain</span>Link, Micro<span class="hlt">Strain</span>, Inc., Williston, VT). Nodes include: 16 bit A/D converter w/programmable gain and filter, 5 single ended or 3 differential sensor inputs, microcontroller w/16 bit address, on-board EEPROM, and 418 MHz FSK RF transmitter. Transmission range was 1/3 mile (LOS, 1/4 wavelength antennas, 12 milliamps at +3 VDC). The RF receiver included EEPROM, XML output, and Ethernet connectivity. Received data from network nodes are parsed according to their individual addresses. The times required to accumulate sufficient charge to accomplish data transmission was evaluated. For peak <span class="hlt">strains</span> of 150 μɛ, the time to transmit was 30 to 160 seconds (for 180 to 60 Hz tests).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3224125','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3224125"><span>Genome organization of epidemic Acinetobacter baumannii <span class="hlt">strains</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2011-01-01</p> <p>Background Acinetobacter baumannii is an opportunistic pathogen responsible for hospital-acquired infections. A. baumannii epidemics described world-wide were caused by few genotypic clusters of <span class="hlt">strains</span>. The occurrence of epidemics caused by multi-drug resistant <span class="hlt">strains</span> assigned to novel genotypes have been reported over the last few years. Results In the present study, we compared whole genome sequences of three A. baumannii <span class="hlt">strains</span> assigned to genotypes ST2, ST25 and ST78, representative of the most frequent genotypes responsible for epidemics in several Mediterranean hospitals, and four complete genome sequences of A. baumannii <span class="hlt">strains</span> assigned to genotypes ST1, ST2 and ST77. Comparative genome analysis showed extensive synteny and identified 3068 coding regions which are conserved, at the same chromosomal position, in all A. baumannii genomes. Genome alignments also identified 63 DNA regions, ranging in size from 4 o 126 kb, all defined as genomic islands, which were present in some genomes, but were either missing or replaced by non-homologous DNA sequences in others. Some islands are involved in resistance to drugs and metals, others carry genes encoding surface proteins or enzymes involved in specific metabolic pathways, and others correspond to prophage-like elements. Accessory DNA regions encode 12 to 19% of the potential gene products of the analyzed <span class="hlt">strains</span>. The analysis of a collection of epidemic A. baumannii <span class="hlt">strains</span> showed that some islands were restricted to specific genotypes. Conclusion The definition of the genome components of A. baumannii provides a scaffold to rapidly evaluate the genomic organization of novel clinical A. baumannii isolates. Changes in island profiling will be useful in genomic epidemiology of A. baumannii population. PMID:21985032</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22328768','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22328768"><span>Genome sequence of Brevibacillus laterosporus <span class="hlt">strain</span> GI-9.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sharma, Vikas; Singh, Pradip K; Midha, Samriti; Ranjan, Manish; Korpole, Suresh; Patil, Prabhu B</p> <p>2012-03-01</p> <p>We report the 5.18-Mb genome sequence of Brevibacillus laterosporus <span class="hlt">strain</span> GI-9, isolated from a subsurface soil sample during a screen for novel <span class="hlt">strains</span> producing antimicrobial compounds. The draft genome of this <span class="hlt">strain</span> will aid in biotechnological exploitation and comparative genomics of Brevibacillus laterosporus <span class="hlt">strains</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20000024984&hterms=new+madrid+seismic+zone&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dnew%2Bmadrid%2Bseismic%2Bzone','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20000024984&hterms=new+madrid+seismic+zone&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dnew%2Bmadrid%2Bseismic%2Bzone"><span>Stresses and <span class="hlt">Strains</span> within the "Stable" North American Plate</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Engeln, Joe</p> <p>1995-01-01</p> <p>This paper presents a final report on "Stresses and <span class="hlt">Strains</span> within the "Stable" North American Plate". The topics include: 1) <span class="hlt">Strain</span> rates near the New Madrid seismic zone; 2) Signal Processing of intermediate term data; and 3) Transform fault stresses and <span class="hlt">strains</span>. The paper also includes graphs of the stress and <span class="hlt">strain</span> distributions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28820384','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28820384"><span>Chronic Wasting Disease Prion <span class="hlt">Strain</span> Emergence and Host Range Expansion.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Herbst, Allen; Velásquez, Camilo Duque; Triscott, Elizabeth; Aiken, Judd M; McKenzie, Debbie</p> <p>2017-09-01</p> <p>Human and mouse prion proteins share a structural motif that regulates resistance to common chronic wasting disease (CWD) prion <span class="hlt">strains</span>. Successful transmission of an emergent <span class="hlt">strain</span> of CWD prion, H95(+), into mice resulted in infection. Thus, emergent CWD prion <span class="hlt">strains</span> may have higher zoonotic potential than common <span class="hlt">strains</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26769927','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26769927"><span>Draft Genome Sequences of Achromobacter piechaudii GCS2, Agrobacterium sp. <span class="hlt">Strain</span> SUL3, Microbacterium sp. <span class="hlt">Strain</span> GCS4, Shinella sp. <span class="hlt">Strain</span> GWS1, and Shinella sp. <span class="hlt">Strain</span> SUS2 Isolated from Consortium with the Hydrocarbon-Producing Alga Botryococcus braunii.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jones, Katy J; Moore, Karen; Sambles, Christine; Love, John; Studholme, David J; Aves, Stephen J</p> <p>2016-01-14</p> <p>A variety of bacteria associate with the hydrocarbon-producing microalga Botryococcus braunii, some of which may influence its growth. We report here the genome sequences for Achromobacter piechaudii GCS2, Agrobacterium sp. <span class="hlt">strain</span> SUL3, Microbacterium sp. <span class="hlt">strain</span> GCS4, and Shinella sp. <span class="hlt">strains</span> GWS1 and SUS2, isolated from a laboratory culture of B. braunii, race B, <span class="hlt">strain</span> Guadeloupe.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4982289','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4982289"><span>Complete Genome Sequence of the Oncolytic Sendai virus <span class="hlt">Strain</span> Moscow</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zainutdinov, Sergei S.; Tikunov, Artem Y.; Matveeva, Olga V.</p> <p>2016-01-01</p> <p>We report here the complete genome sequence of Sendai virus Moscow <span class="hlt">strain</span>. Anecdotal evidence for the efficacy of oncolytic virotherapy exists for this <span class="hlt">strain</span>. The RNA genome of the Moscow <span class="hlt">strain</span> is 15,384 nucleotides in length and differs from the nearest <span class="hlt">strain</span>, BB1, by 18 nucleotides and 11 amino acids. PMID:27516510</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=287069','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=287069"><span>Pheromonal divergence between two <span class="hlt">strains</span> of Spodoptera frugiperda</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>Abstract- Spodoptera frugiperda consists of two genetically and behaviorally different <span class="hlt">strains</span>, the corn- and the rice-<span class="hlt">strain</span>, which seem to be in the process of sympatric speciation. We investigated the role of <span class="hlt">strain</span>-specific sexual communication as a prezygotic mating barrier between both <span class="hlt">strains</span>...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19740031112&hterms=magnesium+oxide&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dmagnesium%2Boxide','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19740031112&hterms=magnesium+oxide&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dmagnesium%2Boxide"><span>Dynamic <span class="hlt">strain</span> aging in magnesium oxide single crystals</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Srinivasan, M.; Stoebe, T. G.</p> <p>1973-01-01</p> <p><span class="hlt">Strain</span> rate change transients are considered together with aspects of serrated flow, questions of flow stress and work hardening during dynamic <span class="hlt">strain</span> aging, and time, temperature, and prestrain dependence of <span class="hlt">strain</span> aging. On continuing the deformation process after aging for certain periods of time for a particular <span class="hlt">strain</span>, a subsidiary load drop is sometimes observed in addition to the main yield drops.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3768671','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3768671"><span>Ciprofloxacin susceptibility reduction of Salmonella <span class="hlt">strains</span> isolated from outbreaks</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Souza, Roberta B.; Ferrari, Rafaela G.; Magnani, Marciane; Kottwitz, Luciana B. M.; Alcocer, Iliana; Tognim, Maria Cristina B.; Oliveira, Tereza C. R. M.</p> <p>2010-01-01</p> <p>The antimicrobial susceptibility of 212 Salmonella <span class="hlt">strains</span> isolated from patients and foods was evaluated and 45% were found to be resistant to nalidixic acid. Nalidixic acid resistant <span class="hlt">strains</span> showed a higher minimal inhibitory concentration for ciprofloxacin than sensitive <span class="hlt">strains</span>. During the study an increase of <span class="hlt">strains</span> with reduced susceptibility to ciprofloxacin was also observed. PMID:24031522</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26655590','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26655590"><span>Ultrasound <span class="hlt">strain</span> mapping of Achilles tendon compressive <span class="hlt">strain</span> patterns during dorsiflexion.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chimenti, Ruth L; Flemister, A Samuel; Ketz, John; Bucklin, Mary; Buckley, Mark R; Richards, Michael S</p> <p>2016-01-04</p> <p>Heel lifts are commonly prescribed to patients with Achilles tendinopathy, yet little is known about the effect on tendon compressive <span class="hlt">strain</span>. The purposes of the current study were to (1) develop a valid and reliable ultrasound elastography technique and algorithm to measure compressive <span class="hlt">strain</span> of human Achilles tendon in vivo, (2) examine the effects of ankle dorsiflexion (lowering via controlled removal of a heel lift and partial squat) on compressive <span class="hlt">strain</span> of the Achilles tendon insertion and (3) examine the relative compressive <span class="hlt">strain</span> between the deep and superficial regions of the Achilles tendon insertion. All tasks started in a position equivalent to standing with a 30mm heel lift. An ultrasound transducer positioned over the Achilles tendon insertion was used to capture radiofrequency images. A non-rigid image registration-based algorithm was used to estimate compressive <span class="hlt">strain</span> of the tendon, which was divided into 2 regions (superficial, deep). The bland-Altman test and intraclass correlation coefficient were used to test validity and reliability. One-way repeated measures ANOVA was used to compare compressive <span class="hlt">strain</span> between regions and across tasks. Compressive <span class="hlt">strain</span> was accurately and reliably (ICC>0.75) quantified. There was greater compressive <span class="hlt">strain</span> during the combined task of lowering and partial squat compared to the lowering (P=.001) and partial squat (P<.001) tasks separately. There was greater compressive <span class="hlt">strain</span> in the deep region of the tendon compared to the superficial for all tasks (P=.001). While these findings need to be examined in a pathological population, heel lifts may reduce tendon compressive <span class="hlt">strain</span> during daily activities. Copyright © 2015 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2293154','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2293154"><span>Development of a <span class="hlt">Strain</span>-Specific Molecular Method for Quantitating Individual Campylobacter <span class="hlt">Strains</span> in Mixed Populations▿</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Elvers, Karen T.; Helps, Christopher R.; Wassenaar, Trudy M.; Allen, Vivien M.; Newell, Diane G.</p> <p>2008-01-01</p> <p>The identification of sites resulting in cross-contamination of poultry flocks in the abattoir and determination of the survival and persistence of campylobacters at these sites are essential for the development of intervention strategies aimed at reducing the microbial burden on poultry at retail. A novel molecule-based method, using <span class="hlt">strain</span>- and genus-specific oligonucleotide probes, was developed to detect and enumerate specific campylobacter <span class="hlt">strains</span> in mixed populations. <span class="hlt">Strain</span>-specific oligonucleotide probes were designed for the short variable regions (SVR) of the flaA gene in individual Campylobacter jejuni <span class="hlt">strains</span>. A 16S rRNA Campylobacter genus-specific probe was also used. Both types of probes were used to investigate populations of campylobacters by colony lift hybridization. The specificity and proof of principle of the method were tested using <span class="hlt">strains</span> with closely related SVR sequences and mixtures of these <span class="hlt">strains</span>. Colony lifts of campylobacters were hybridized sequentially with up to two labeled <span class="hlt">strain</span>-specific probes, followed by the generic 16S rRNA probe. SVR probes were highly specific, differentiating down to 1 nucleotide in the target sequence, and were sufficiently sensitive to detect colonies of a single <span class="hlt">strain</span> in a mixed population. The 16S rRNA probe detected all Campylobacter spp. tested but not closely related species, such as Arcobacter skirrowi and Helicobacter pullorum. Preliminary field studies demonstrated the application of this technique to target <span class="hlt">strains</span> isolated from poultry transport crate wash tank water. This method is quantitative, sensitive, and highly specific and allows the identification and enumeration of selected <span class="hlt">strains</span> among all of the campylobacters in environmental samples. PMID:18281428</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16988334','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16988334"><span>Nucleic acid extraction from Agrobacterium <span class="hlt">strains</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wise, Arlene A; Liu, Zhenying; Binns, Andrew N</p> <p>2006-01-01</p> <p>Agrobacterium is routinely used as a tool for moving genetic constructs into plant cells. The successful use of Agrobacterium as a tool for the genetic engineering of plant cells often requires the manipulation and analysis of nucleic acids present in recombinant Agrobacterium <span class="hlt">strains</span>. Here we present dependable methods for the isolation of genomic (total) DNA, mega-plasmid DNA, shuttle or binary plasmid DNA, and RNA. In addition, we provide a simple method for the electronic transfer of shuttle plasmids from Agrobacterium to E. coli for use when their low copy number in Agrobacterium impedes plasmid isolation from that <span class="hlt">strain</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930022369','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930022369"><span>Progress in speckle-shift <span class="hlt">strain</span> measurement</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lant, Christian T.; Barranger, John P.; Oberle, Lawrence G.; Greer, Lawrence C., III</p> <p>1991-01-01</p> <p>The Instrumentation and Control Technology Division of the Lewis Research Center has been developing an in-house capability to make one dimensional and two dimensional optical <span class="hlt">strain</span> measurements on high temperature test specimens. The measurements are based on a two-beam speckle-shift technique. The development of composite materials for use in high temperature applications is generating interest in using the speckle-shift technique to measure <span class="hlt">strains</span> on small diameter fibers and wires of various compositions. The results of preliminary speckle correlation tests on wire and fiber specimens are covered, and the advanced system currently under development is described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170007760','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170007760"><span>Unsteady Aerodynamic Force Sensing from <span class="hlt">Strain</span> Data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pak, Chan-Gi</p> <p>2017-01-01</p> <p>A simple approach for computing unsteady aerodynamic forces from simulated measured <span class="hlt">strain</span> data is proposed in this study. First, the deflection and slope of the structure are computed from the unsteady <span class="hlt">strain</span> using the two-step approach. Velocities and accelerations of the structure are computed using the autoregressive moving average model, on-line parameter estimator, low-pass filter, and a least-squares curve fitting method together with analytical derivatives with respect to time. Finally, aerodynamic forces over the wing are computed using modal aerodynamic influence coefficient matrices, a rational function approximation, and a time-marching algorithm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JMPSo..87..177C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JMPSo..87..177C"><span>Cells as <span class="hlt">strain</span>-cued automata</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cox, Brian N.; Snead, Malcolm L.</p> <p>2016-02-01</p> <p>We argue in favor of representing living cells as automata and review demonstrations that autonomous cells can form patterns by responding to local variations in the <span class="hlt">strain</span> fields that arise from their individual or collective motions. An autonomous cell's response to <span class="hlt">strain</span> stimuli is assumed to be effected by internally-generated, internally-powered forces, which generally move the cell in directions other than those implied by external energy gradients. Evidence of cells acting as <span class="hlt">strain</span>-cued automata have been inferred from patterns observed in nature and from experiments conducted in vitro. Simulations that mimic particular cases of pattern forming share the idealization that cells are assumed to pass information among themselves solely via mechanical boundary conditions, i.e., the tractions and displacements present at their membranes. This assumption opens three mechanisms for pattern formation in large cell populations: wavelike behavior, kinematic feedback in cell motility that can lead to sliding and rotational patterns, and directed migration during invasions. Wavelike behavior among ameloblast cells during amelogenesis (the formation of dental enamel) has been inferred from enamel microstructure, while <span class="hlt">strain</span> waves in populations of epithelial cells have been observed in vitro. One hypothesized kinematic feedback mechanism, "enhanced shear motility", accounts successfully for the spontaneous formation of layered patterns during amelogenesis in the mouse incisor. Directed migration is exemplified by a theory of invader cells that sense and respond to the <span class="hlt">strains</span> they themselves create in the host population as they invade it: analysis shows that the <span class="hlt">strain</span> fields contain positional information that could aid the formation of cell network structures, stabilizing the slender geometry of branches and helping govern the frequency of branch bifurcation and branch coalescence (the formation of closed networks). In simulations of pattern formation in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860025310&hterms=contour&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dcontour','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860025310&hterms=contour&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dcontour"><span>Shear-<span class="hlt">strain</span> contours from moire interferometry</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Post, D.; Czarnek, R.; Joh, D.</p> <p>1985-01-01</p> <p>The development of whole-field contour maps of shear <span class="hlt">strains</span> gamma (xy), derived from displacement fields obtained by moire interferometry with 2400 lines/mm, is described. The use of mechanical differentiation to obtain cross-derivatives of displacements and the use of graphical additive moire to sum the cross-derivatives are explained. Quantitative analysis in the small-<span class="hlt">strain</span> domain is possible because of the high sensitivity of moire interferometry. The applicability of this technique is shown by the testing of a short epoxy beam under three-point bending.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/840807','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/840807"><span>Traumatic injuries: office treatment of <span class="hlt">strain</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ryan, A J</p> <p>1977-03-01</p> <p><span class="hlt">Strain</span>, defined as trauma to a musculotendinous unit, is characterized by pain, muscle spasm, swelling, and loss of range of motion. Conservative treatment consists of rest and elevation of the affected muscle, application of ice and compression, active and passive stretching, and resisted motion exercises. If rupture of muscle and fascia is extensive, surgery may be required. Chronic <span class="hlt">strain</span> may result from repeated injuries. It is usually treated with rest and administration of an anti-inflammatory agent, such as oxyphenbutazone or a corticosteroid preparation. In the event that this regimen does not provide relief from pain and disability, surgery may be necessary.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/920878','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/920878"><span>Enabling <span class="hlt">Strain</span> Hardening Simulations with Dislocation Dynamics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Arsenlis, A; Cai, W</p> <p>2006-12-20</p> <p>Numerical algorithms for discrete dislocation dynamics simulations are investigated for the purpose of enabling <span class="hlt">strain</span> hardening simulations of single crystals on massively parallel computers. The algorithms investigated include the /(N) calculation of forces, the equations of motion, time integration, adaptive mesh refinement, the treatment of dislocation core reactions, and the dynamic distribution of work on parallel computers. A simulation integrating all of these algorithmic elements using the Parallel Dislocation Simulator (ParaDiS) code is performed to understand their behavior in concert, and evaluate the overall numerical performance of dislocation dynamics simulations and their ability to accumulate percents of plastic <span class="hlt">strain</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19750023410','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19750023410"><span>NASTRAN modifications for recovering <span class="hlt">strains</span> and curvatures</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hennrich, C. W.</p> <p>1975-01-01</p> <p>Modifications to the NASTRAN structural analysis computer program are described. The modifications allow the recovery of <span class="hlt">strain</span> and curvature data for the general two-dimensional elements, in addition to the usual stress data. Option features allow the transformation of the <span class="hlt">strain</span>/curvature (or stress) data to a common coordinate system and representation at the grid points of the structural model rather than at the conventional element center locations. Usage information is provided which will allow present users of NASTRAN to easily utilize the new capability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17155419','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17155419"><span>Phosphorus donors in highly <span class="hlt">strained</span> silicon.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Huebl, Hans; Stegner, Andre R; Stutzmann, Martin; Brandt, Martin S; Vogg, Guenther; Bensch, Frank; Rauls, Eva; Gerstmann, Uwe</p> <p>2006-10-20</p> <p>The hyperfine interaction of phosphorus donors in fully <span class="hlt">strained</span> Si thin films grown on virtual Si(1-x)Ge(x) substrates with x< or =0.3 is determined via electrically detected magnetic resonance. For highly <span class="hlt">strained</span> epilayers, hyperfine interactions as low as 0.8 mT are observed, significantly below the limit predicted by valley repopulation. Within a Green's function approach, density functional theory shows that the additional reduction is caused by the volume increase of the unit cell and a relaxation of the Si ligands of the donor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvB..95x5418S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvB..95x5418S"><span>Propagating edge states in <span class="hlt">strained</span> honeycomb lattices</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Salerno, Grazia; Ozawa, Tomoki; Price, Hannah M.; Carusotto, Iacopo</p> <p>2017-06-01</p> <p>We investigate the helically propagating edge states associated with pseudo-Landau levels in <span class="hlt">strained</span> honeycomb lattices. We exploit chiral symmetry to derive a general criterion for the existence of these propagating edge states in the presence of only nearest-neighbor hoppings and we verify our criterion using numerical simulations of both uniaxially and trigonally <span class="hlt">strained</span> honeycomb lattices. We show that the propagation of the helical edge state can be controlled by engineering the shape of the edges. Sensitivity to chiral-symmetry-breaking next-nearest-neighbor hoppings is assessed. Our result opens up an avenue toward the precise control of edge modes through manipulation of the edge shape.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730009719','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730009719"><span>Development of high temperature <span class="hlt">strain</span> gages</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lemcoe, M. M.</p> <p>1973-01-01</p> <p>High temperature electric resistance wire <span class="hlt">strain</span> gages were developed and evaluated for use at temperatures exceeding 922 K (1200 F). A special high temperature <span class="hlt">strain</span> gage alloy (Fe-25Cr-7.5A1), designated BCL-3, was used to fabricate the gages. Pertinent gage characteristics were determined at temperatures up to 1255 K (1800 F). The results of the evaluation were reported in graphical and tabular form. It was concluded that the gages will perform satisfactorily at temperatures to at least 1089 K (1500 F) for at least one hour.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22734363','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22734363"><span>Principles and clinical applications of <span class="hlt">strain</span> imaging.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Govind, Satish C; Kiotsekoglou, Anatoli; Gopal, Aasha S; Brodin, Lars Ake; Ramesh; Saha, Samir K</p> <p>2011-01-01</p> <p>M-Mode echocardiography, 2-D grey scale imaging and standard Doppler that constitute conventional echocardiography has been used for over many decades now. Although these modalities form the backbone in routine clinical echocardiography, its inability to objectively quantify left ventricular function at regional and global levels as well as its loading and heart rate dependency make conventional echocardiography an incomplete tool in clinical situations. Tissue Doppler imaging (which includes myocardial velocity, displacement and <span class="hlt">strain</span>) has been successfully used in a variety of clinical situations, from investigations of diastolic function to implantation of bi-ventricular pacing for cardiac resynchronization therapy and even in preclinical diagnosis of genetic diseases such as hypertrophic cardiomyopathy. <span class="hlt">Strain</span> imaging has been found to be superior to velocity in a variety of clinical conditions and enables us to quantify deformation as a measurable number in terms of regional myocardial deformation. <span class="hlt">Strain</span> and <span class="hlt">strain</span> rate have to be assessed together since they provide complementary information somewhat analogous to ejection fraction and contraction. This article has tried to simplify its principles, understand its limitations and know its utility to ensure having a better knowledge of this promising tool before one starts to actively use it. In this review, focus has been made on the physical, technical and also clinical aspects of <span class="hlt">strain</span> imaging. In the new world of multi-modality imaging, cardiac magnetic resonance imaging (CMR) and nuclear perfusion scintigraphy (NPS) are the competitors of echocardiography, but it would be of interest to note that even these modalities are also adapting concepts of <span class="hlt">strain</span> imaging (in CMR) and left ventricular synchronicity (in NPS). This only emphasizes the role of advanced echocardiography as a more economical and stand-alone modality visa vis the other two related technologies. The sooner we adapt to these advanced</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007ApPhL..91y1912C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007ApPhL..91y1912C"><span><span class="hlt">Strain</span> responsive concave and convex microlens arrays</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chandra, Dinesh; Yang, Shu; Lin, Pei-Chun</p> <p>2007-12-01</p> <p>We report the fabrication of single-component, <span class="hlt">strain</span> responsive microlens arrays with real-time tunability. The concave lens array is fabricated by patterning hard oxide layer on a bidirectionally prestretched soft elastomer, poly(dimethylsiloxane) (PDMS) followed by confined buckling upon release of the prestrain. The convex microlens array is replica molded from the concave lenses in PDMS. Due to difference in lens formation mechanisms, the two types of lenses show different tunable range of focal length in response to the applied <span class="hlt">strain</span>: large focal length change is observed from the concave microlens array, whereas that from the convex microlens array is much smaller.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992ONERA....Q....K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992ONERA....Q....K"><span>High temperature thin film <span class="hlt">strain</span> gauges</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kayser, P.; Godefroy, J. C.; Leca, L.</p> <p></p> <p>The development of thin-film resistance <span class="hlt">strain</span> gauges suitable for dynamic stress measurements up to 900 C and intended for blade vibration measurements is reported. The <span class="hlt">strain</span> gauge is deposited by RF sputtering on nickel-base superalloys and consists of an NiCoCrAlY coating, an Al2O3 insulating layer, a sensing layer (NiCr, PdCr), an intermediate splicing layer (Pt), and a protective film (Al2O3 or SiO2). The electrical and mechanical properties of the sensing layers and preliminary results on the thermal stability of the gauges are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19960018814&hterms=mcneill&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmcneill','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19960018814&hterms=mcneill&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmcneill"><span>Computing Displacements And <span class="hlt">Strains</span> From Video Images</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Russell, Samuel S.; Mcneill, Stephen R.; Lansing, Matthew D.</p> <p>1996-01-01</p> <p>Subpixel digital video image correlation (SDVIC) technique for measuring in-plane displacements on surfaces of objects under loads, without contact. Used for analyses of experimental research specimens or actual service structures of virtually any size or material. Only minimal preparation of test objects needed, and no need to isolate test objects from minor vibrations or fluctuating temperatures. Technique implemented by SDVIC software, producing color-graduated, full-field representations of in-plane displacements and partial derivatives with respect to position along both principal directions in each image plane. From representations, linear <span class="hlt">strains</span>, shear <span class="hlt">strains</span>, and rotation fields determined. Written in C language.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MeScT..28a5106K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MeScT..28a5106K"><span>Atmospheric corrosion sensor based on <span class="hlt">strain</span> measurement</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kasai, Naoya; Hiroki, Masatoshi; Yamada, Toshirou; Kihira, Hiroshi; Matsuoka, Kazumi; Kuriyama, Yukihisa; Okazaki, Shinji</p> <p>2017-01-01</p> <p>In this paper, an in situ atmospheric corrosion sensor based on <span class="hlt">strain</span> measurement is discussed. The theoretical background for measuring the reduction in thickness of low carbon steel is also presented. Based on the theoretical considerations, a test piece and apparatus for an atmospheric corrosion sensor were designed. Furthermore, in a dry-wet cyclic accelerated exposure experiment, the measured <span class="hlt">strain</span> indicated thinning of the test piece, although the corrosion product generated on the surface of the test piece affected the results. The atmospheric corrosion sensor would be effective for evaluating atmospheric corrosion of many types of infrastructure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22267707','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22267707"><span>Tensile <span class="hlt">strain</span> mapping in flat germanium membranes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rhead, S. D. Halpin, J. E.; Myronov, M.; Patchett, D. H.; Allred, P. S.; Wilson, N. R.; Leadley, D. R.; Shah, V. A.; Kachkanov, V.; Dolbnya, I. P.; Reparaz, J. S.; Sotomayor Torres, C. M.</p> <p>2014-04-28</p> <p>Scanning X-ray micro-diffraction has been used as a non-destructive probe of the local crystalline quality of a thin suspended germanium (Ge) membrane. A series of reciprocal space maps were obtained with ∼4 μm spatial resolution, from which detailed information on the <span class="hlt">strain</span> distribution, thickness, and crystalline tilt of the membrane was obtained. We are able to detect a systematic <span class="hlt">strain</span> variation across the membranes, but show that this is negligible in the context of using the membranes as platforms for further growth. In addition, we show evidence that the interface and surface quality is improved by suspending the Ge.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AIPC.1389.1228E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AIPC.1389.1228E"><span>Ecoepidemics with Two <span class="hlt">Strains</span>: Diseased Prey.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Elena, Elisa; Grammauro, Maria; Venturino, Ezio</p> <p>2011-09-01</p> <p>In this work we present a minimal model for an ecoepidemic situation with two diseases affecting the prey population. The main assumptions are the following ones. The predators recognize and hunt only the healthy prey. An infected prey of one <span class="hlt">strain</span> becomes immune to the other one. The major finding shows that the two <span class="hlt">strains</span> cannot simultaneously thrive in the system, contrary to the standard assumptions in epidemiology. But this rather unexpected and remarkable result, paralleling another one when the epidemics affects the predators, is most likely due to the assumptions made.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=243828','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=243828"><span>Comparison of Ethanol Production by Different Zymomonas <span class="hlt">Strains</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Skotnicki, M. L.; Lee, K. J.; Tribe, D. E.; Rogers, P. L.</p> <p>1981-01-01</p> <p>A comparison of the rates of growth and ethanol production by 11 different <span class="hlt">strains</span> of Zymomonas revealed a wide range of characteristics, with some <span class="hlt">strains</span> being more tolerant of high sugar or ethanol concentrations and high incubation temperatures than others. Some <span class="hlt">strains</span> were unable to utilize sucrose; others produced large amounts of levan, and one <span class="hlt">strain</span> grew well but produced no levan. One <span class="hlt">strain</span>, CP4, was considerably better in all respects than most of the other <span class="hlt">strains</span> and was chosen as a starting <span class="hlt">strain</span> for genetic improvement of ethanol production. PMID:16345753</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9798E..37N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9798E..37N"><span>Novel pre-<span class="hlt">strain</span> method for dielectric electroactive polymers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Newell, Brittany; Krutz, Gary; Stewart, Frank; Pascal, Kevin</p> <p>2016-04-01</p> <p>Dielectric electroactive polymers have demonstrated their significant potential in a variety of applications due to their material strength and elastomeric material properties. Mechanical pre-<span class="hlt">strain</span> has been shown to enhance material actuation potential significantly. However, with this enhancement comes sacrifices. Mechanical pre-<span class="hlt">strain</span> imposes a stiff mechanical boundary on the dielectric material in order to maintain the <span class="hlt">strain</span>. In this research, investigations were made into the mechanisms of mechanical pre-<span class="hlt">strain</span> and into alternate pre-<span class="hlt">strain</span> methods. These studies discovered alternate methods capable of producing enhanced pre-<span class="hlt">strains</span> and final actuation without the addition of the solid <span class="hlt">strain</span> boundary.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1388493','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1388493"><span>Variability among Rhizobium <span class="hlt">Strains</span> Originating from Nodules of Vicia faba</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>van Berkum, P.; Beyene, D.; Vera, F. T.; Keyser, H. H.</p> <p>1995-01-01</p> <p>Rhizobium <span class="hlt">strains</span> from nodules of Vicia faba were diverse in plasmid content and serology. Results of multilocus gel electrophoresis and restriction fragment length polymorphism indicated several deep chromosomal lineages among the <span class="hlt">strains</span>. Linkage disequilibrium among the chromosomal types was detected and may have reflected variation of Rhizobium <span class="hlt">strains</span> in the different geographical locations from which the <span class="hlt">strains</span> originated. An investigation of pea <span class="hlt">strains</span> with antibodies prepared against fava bean <span class="hlt">strains</span> and restriction fragment length polymorphism analyses, targeting DNA regions coding for rRNA and nodulation, indicated that Rhizobium <span class="hlt">strains</span> from V. faba nodules were distinguishable from those from Pisum sativum, V. villosa, and Trifolium spp. PMID:16535075</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4178652','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4178652"><span>Dynamics of Dual Infection with Campylobacter jejuni <span class="hlt">Strains</span> in Chickens Reveals Distinct <span class="hlt">Strain-to-Strain</span> Variation in Infection Ecology</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wigley, Paul; Humphrey, Suzanne; Kemmett, Kirsty; Lacharme-Lora, Lizeth; Humphrey, Tom; Williams, Nicola</p> <p>2014-01-01</p> <p>Although multiple genotypes of Campylobacter jejuni may be isolated from the same commercial broiler flock, little is known about the infection dynamics of different genotypes within individuals or their colonization sites within the gut. Single experimental infections with C. jejuni M1 (sequence type 137, clonal complex 45) and C. jejuni 13126 (sequence type 21, clonal complex 21) revealed that 13126 colonized the ceca at significantly higher levels. The dissemination and colonization sites of the two C. jejuni <span class="hlt">strains</span> then were examined in an experimental broiler flock. Two 33-day-old broiler chickens were infected with M1 and two with 13126, and 15 birds were left unchallenged. Cloacal swabs were taken postinfection to determine the colonization and shedding of each <span class="hlt">strain</span>. By 2 days postinfection (dpi), 8/19 birds were shedding M1 whereas none were shedding 13126. At 8 dpi, all birds were shedding both <span class="hlt">strains</span>. At 18 dpi, liver and cecal levels of each isolate were quantified, while in 10 birds they also were quantified at nine sites throughout the gastrointestinal (GI) tract. 13126 was found throughout the GI tract, while M1 was largely restricted to the ceca and colon. The livers of 7/19 birds were culture positive for 13126 only. These data show that 13126 has a distinctly different infection biology than <span class="hlt">strain</span> M1. It showed slower colonization of the lower GI tract but was more invasive and able to colonize at a high level throughout the GI tract. The finding that C. jejuni <span class="hlt">strains</span> have markedly different infection ecologies within the chicken has implications for control in the poultry industry and suggests that the contamination risk of edible tissues is dependent on the isolate involved. PMID:25107966</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRB..120.4556H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRB..120.4556H"><span>Revisiting borehole <span class="hlt">strain</span>, typhoons, and slow earthquakes using quantitative estimates of precipitation-induced <span class="hlt">strain</span> changes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hsu, Ya-Ju; Chang, Yuan-Shu; Liu, Chi-Ching; Lee, Hsin-Ming; Linde, Alan T.; Sacks, Selwyn I.; Kitagawa, Genshio; Chen, Yue-Gau</p> <p>2015-06-01</p> <p>Taiwan experiences high deformation rates, particularly along its eastern margin where a shortening rate of about 30 mm/yr is experienced in the Longitudinal Valley and the Coastal Range. Four Sacks-Evertson borehole strainmeters have been installed in this area since 2003. Liu et al. (2009) proposed that a number of <span class="hlt">strain</span> transient events, primarily coincident with low-barometric pressure during passages of typhoons, were due to deep-triggered slow slip. Here we extend that investigation with a quantitative analysis of the <span class="hlt">strain</span> responses to precipitation as well as barometric pressure and the Earth tides in order to isolate tectonic source effects. Estimates of the <span class="hlt">strain</span> responses to barometric pressure and groundwater level changes for the different stations vary over the ranges -1 to -3 nanostrain/millibar(hPa) and -0.3 to -1.0 nanostrain/hPa, respectively, consistent with theoretical values derived using Hooke's law. Liu et al. (2009) noted that during some typhoons, including at least one with very heavy rainfall, the observed <span class="hlt">strain</span> changes were consistent with only barometric forcing. By considering a more extensive data set, we now find that the <span class="hlt">strain</span> response to rainfall is about -5.1 nanostrain/hPa. A larger <span class="hlt">strain</span> response to rainfall compared to that to air pressure and water level may be associated with an additional <span class="hlt">strain</span> from fluid pressure changes that take place due to infiltration of precipitation. Using a state-space model, we remove the <span class="hlt">strain</span> response to rainfall, in addition to those due to air pressure changes and the Earth tides, and investigate whether corrected <span class="hlt">strain</span> changes are related to environmental disturbances or tectonic-original motions. The majority of <span class="hlt">strain</span> changes attributed to slow earthquakes seem rather to be associated with environmental factors. However, some events show remaining <span class="hlt">strain</span> changes after all corrections. These events include <span class="hlt">strain</span> polarity changes during passages of typhoons (a characteristic that is</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19353890','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19353890"><span>[Effects of different iron concentrations on the growths of a unicellular <span class="hlt">strain</span> and a colonial <span class="hlt">strain</span> of Microcystis aeruginosa].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Yu-wen; Li, Jian-hong; Fu, Lu; Wu, Min; Weng, Yong-ping; Zhou, Yao-ming</p> <p>2009-01-01</p> <p>We investigated the growth, photosynthetic efficiency, siderophore production and iron accumulation of two <span class="hlt">strains</span> of M. aeruginosa, a unicellular <span class="hlt">strain</span> M. aeruginosa PCC7806 and a colonial <span class="hlt">strain</span> M. aeruginosa XW01, under iron-limited and iron-replete conditions. The identities of ITS and fur gene sequences of two <span class="hlt">strains</span> were 95% and 98% respectively.That implied the two <span class="hlt">strains</span> should be close relatives. Results showed the growths of two <span class="hlt">strains</span> were severely inhibited under an iron-limited condition. The unicellular <span class="hlt">strain</span> died in 6 days,whereas the colonial <span class="hlt">strain</span> could maintain a weak growth in 10 days under the iron-limited condition. PSII maximum light energy transformation (Fv/Fm) of the colonial <span class="hlt">strain</span> and the unicellular <span class="hlt">strain</span> were 0.182 +/- 0.014 and 0.160 +/- 0.017, respectively. The colonial <span class="hlt">strain</span> displayed a higher photosynthetic oxygen evolution than the unicellular <span class="hlt">strain</span>. Two <span class="hlt">strains</span> could produce siderophores, which were hydroxamate type. The colonial <span class="hlt">strain</span> produced more siderophores than unicellular <span class="hlt">strain</span> under the iron-limited condition.Iron contents of two <span class="hlt">strains</span> were less than 1/3 cultured in the iron-limited condition than in iron-replete condition, but no obvious difference appeared between the two <span class="hlt">strains</span>. Our result demonstrated that the colonial <span class="hlt">strain</span> have a stronger endurance than unicellular <span class="hlt">strain</span> under the iron-limited condition. As two <span class="hlt">strains</span> had almost same abilities of iron accumulation, the other physiological mechanisms in the unicellular <span class="hlt">strain</span> should be more sensitive to lower iron level.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA573739','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA573739"><span>High <span class="hlt">Strain</span> Rate Tensile and Compressive Effects in Glassy Polymers</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2013-02-08</p> <p>polymers under high <span class="hlt">strain</span> rates has been determined in compression. Some research programs have studied the combined effects of temperature and <span class="hlt">strain</span> rate...glassy polymers to high <span class="hlt">strain</span> rate loading in compression. More recently, research programs that study the combined effects of temperature and <span class="hlt">strain</span>...Force Materiel Command  United States Air Force  Eglin Air Force Base AFRL-RW-EG-TP-2013-006 High <span class="hlt">Strain</span> Rate</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA208826','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA208826"><span>High-<span class="hlt">Strain</span> Rate Testing of Gun Propellants</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1988-12-01</p> <p>specimen is loaded beyond the elastic range. Instrumentation of the bars allows recording of the <span class="hlt">strain</span> history in the bars during the test event. The...<span class="hlt">strain</span> history on the input bar gives a record of the <span class="hlt">strain</span> rate history in the sample. )The output bar <span class="hlt">strain</span> history is proportional to the stress... history in the sample.) The data were compared to the results reported in the literature of earlier high <span class="hlt">strain</span> rate tests on the same propellants. 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