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Sample records for pantoea agglomerans strains

  1. Phylogeny and identification of Pantoea species and typing of Pantoea agglomerans strains by multilocus gene sequencing.

    PubMed

    Delétoile, Alexis; Decré, Dominique; Courant, Stéphanie; Passet, Virginie; Audo, Jennifer; Grimont, Patrick; Arlet, Guillaume; Brisse, Sylvain

    2009-02-01

    Pantoea agglomerans and other Pantoea species cause infections in humans and are also pathogenic to plants, but the diversity of Pantoea strains and their possible association with hosts and disease remain poorly known, and identification of Pantoea species is difficult. We characterized 36 Pantoea strains, including 28 strains of diverse origins initially identified as P. agglomerans, by multilocus gene sequencing based on six protein-coding genes, by biochemical tests, and by antimicrobial susceptibility testing. Phylogenetic analysis and comparison with other species of Enterobacteriaceae revealed that the genus Pantoea is highly diverse. Most strains initially identified as P. agglomerans by use of API 20E strips belonged to a compact sequence cluster together with the type strain, but other strains belonged to diverse phylogenetic branches corresponding to other species of Pantoea or Enterobacteriaceae and to probable novel species. Biochemical characteristics such as fosfomycin resistance and utilization of d-tartrate could differentiate P. agglomerans from other Pantoea species. All 20 strains of P. agglomerans could be distinguished by multilocus sequence typing, revealing the very high discrimination power of this method for strain typing and population structure in this species, which is subdivided into two phylogenetic groups. PCR detection of the repA gene, associated with pathogenicity in plants, was positive in all clinical strains of P. agglomerans, suggesting that clinical and plant-associated strains do not form distinct populations. We provide a multilocus gene sequencing method that is a powerful tool for Pantoea species delineation and identification and for strain tracking.

  2. Genotypic comparison of Pantoea agglomerans plant and clinical strains

    PubMed Central

    2009-01-01

    Background Pantoea agglomerans strains are among the most promising biocontrol agents for a variety of bacterial and fungal plant diseases, particularly fire blight of apple and pear. However, commercial registration of P. agglomerans biocontrol products is hampered because this species is currently listed as a biosafety level 2 (BL2) organism due to clinical reports as an opportunistic human pathogen. This study compares plant-origin and clinical strains in a search for discriminating genotypic/phenotypic markers using multi-locus phylogenetic analysis and fluorescent amplified fragment length polymorphisms (fAFLP) fingerprinting. Results Majority of the clinical isolates from culture collections were found to be improperly designated as P. agglomerans after sequence analysis. The frequent taxonomic rearrangements underwent by the Enterobacter agglomerans/Erwinia herbicola complex may be a major problem in assessing clinical associations within P. agglomerans. In the P. agglomerans sensu stricto (in the stricter sense) group, there was no discrete clustering of clinical/biocontrol strains and no marker was identified that was uniquely associated to clinical strains. A putative biocontrol-specific fAFLP marker was identified only in biocontrol strains. The partial ORF located in this band corresponded to an ABC transporter that was found in all P. agglomerans strains. Conclusion Taxonomic mischaracterization was identified as a major problem with P. agglomerans, and current techniques removed a majority of clinical strains from this species. Although clear discrimination between P. agglomerans plant and clinical strains was not obtained with phylogenetic analysis, a single marker characteristic of biocontrol strains was identified which may be of use in strain biosafety determinations. In addition, the lack of Koch's postulate fulfilment, rare retention of clinical strains for subsequent confirmation, and the polymicrobial nature of P. agglomerans clinical reports

  3. Phylogeny and Identification of Pantoea Species and Typing of Pantoea agglomerans Strains by Multilocus Gene Sequencing ▿ †

    PubMed Central

    Delétoile, Alexis; Decré, Dominique; Courant, Stéphanie; Passet, Virginie; Audo, Jennifer; Grimont, Patrick; Arlet, Guillaume; Brisse, Sylvain

    2009-01-01

    Pantoea agglomerans and other Pantoea species cause infections in humans and are also pathogenic to plants, but the diversity of Pantoea strains and their possible association with hosts and disease remain poorly known, and identification of Pantoea species is difficult. We characterized 36 Pantoea strains, including 28 strains of diverse origins initially identified as P. agglomerans, by multilocus gene sequencing based on six protein-coding genes, by biochemical tests, and by antimicrobial susceptibility testing. Phylogenetic analysis and comparison with other species of Enterobacteriaceae revealed that the genus Pantoea is highly diverse. Most strains initially identified as P. agglomerans by use of API 20E strips belonged to a compact sequence cluster together with the type strain, but other strains belonged to diverse phylogenetic branches corresponding to other species of Pantoea or Enterobacteriaceae and to probable novel species. Biochemical characteristics such as fosfomycin resistance and utilization of d-tartrate could differentiate P. agglomerans from other Pantoea species. All 20 strains of P. agglomerans could be distinguished by multilocus sequence typing, revealing the very high discrimination power of this method for strain typing and population structure in this species, which is subdivided into two phylogenetic groups. PCR detection of the repA gene, associated with pathogenicity in plants, was positive in all clinical strains of P. agglomerans, suggesting that clinical and plant-associated strains do not form distinct populations. We provide a multilocus gene sequencing method that is a powerful tool for Pantoea species delineation and identification and for strain tracking. PMID:19052179

  4. 40 CFR 180.1272 - Pantoea agglomerans strain E325; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Pantoea agglomerans strain E325... RESIDUES IN FOOD Exemptions From Tolerances § 180.1272 Pantoea agglomerans strain E325; exemption from the... Pantoea agglomerans strain E325 when used on apples and pears....

  5. 40 CFR 180.1272 - Pantoea agglomerans strain E325; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Pantoea agglomerans strain E325... RESIDUES IN FOOD Exemptions From Tolerances § 180.1272 Pantoea agglomerans strain E325; exemption from the... Pantoea agglomerans strain E325 when used on apples and pears....

  6. 40 CFR 180.1272 - Pantoea agglomerans strain E325; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Pantoea agglomerans strain E325... RESIDUES IN FOOD Exemptions From Tolerances § 180.1272 Pantoea agglomerans strain E325; exemption from the... Pantoea agglomerans strain E325 when used on apples and pears....

  7. 40 CFR 180.1272 - Pantoea agglomerans strain E325; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Pantoea agglomerans strain E325... RESIDUES IN FOOD Exemptions From Tolerances § 180.1272 Pantoea agglomerans strain E325; exemption from the... Pantoea agglomerans strain E325 when used on apples and pears....

  8. 40 CFR 180.1272 - Pantoea agglomerans strain E325; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Pantoea agglomerans strain E325... RESIDUES IN FOOD Exemptions From Tolerances § 180.1272 Pantoea agglomerans strain E325; exemption from the... Pantoea agglomerans strain E325 when used on apples and pears....

  9. [Characterization of Pantoea agglomerans lipopolysaccharides].

    PubMed

    Varbanets, L D; Brovarskaya, O S; Bulygina, T N; Garkavaya, E G; Zhitkevich, N V

    2014-01-01

    Lipopolysaccharides (LPS) from seven Pantoea agglomerans strains isolated from various plants were purified and chemically identified. LPS of the studied P. agglomerans strains were heterogeneous in monosaccharide composition. Thus, the LPS of P. agglomerans 8606 differed considerably from the LPSs of other strains, containing mannose as the predominant monosaccharide (69.8%), as well as ribose (15.1%) and xylose (12.6%), while the content of rhamnose, one of the predominant monosaccharides in other LPS samples, was 2.5%. Analysis of the fatty acid composition revealed the presence of C12-C16 acids. In lipids A of all the studied strains, 3-OH-C14:0 was the predominant acid (31.7 to 39.1%, depending on the strain). C12:0 (8.2 to 31.5%), C14:0 (12.9 to 30.8%), and C16:0 acids (3.4 to 16.9%) were also revealed. The studied P. agglomerans strains fell into three groups according to their fatty acid composition. The differences stemmed from the presence or absence of two fatty acids, 2-OH-C14:0 and C16:1. Ouchterlony double immunodiffusion in agar revealed that all the LPS under study exhibited antigenic activity in homologous systems. The results of serological cross reactions indicated immunochemical heterogeneity of the species P. agglomerans. Comparative investigation of the complex of parameters of peripheral blood cells from a healthy donor before and after treatment with LPS solutions showed that the values of no parameters exceeded the normal range.

  10. Antibiosis by Pantoea agglomerans biocontrol strain E325 against Erwinia amylovora on apple blossom stigmas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pantoea agglomerans E325, the active ingredient in a commercial product for fire blight control, was previously shown in vitro to produce a unique alkaline- and phosphate-sensitive antibiotic specific to Erwinia amylovora. Antibiosis was evaluated as a mode of antagonism on blossom stigmas using two...

  11. Antibiosis and acidification by Pantoea agglomerans strain E325 may contribute to suppression of Erwinia amylovora.

    PubMed

    Pusey, P L; Stockwell, V O; Rudell, D R

    2008-10-01

    Pantoea agglomerans strain E325, a commercially available antagonist for fire blight of apple and pear, was originally selected through screening based on suppression of Erwinia amylovora on flower stigmas, but specific mechanisms of antagonism were unknown. Bacterial modification of pH was evaluated as a possible mechanism by analyzing stigma exudates extracted from 'Gala' apple stigmas. The pH values for field samples were only slightly lower than controls, but indicated a range (pH 5 to 6) conducive for antibiotic activity according to subsequent assays. Under low-phosphate and low-pH conditions, an antibacterial product of E325 with high specificity to E. amylovora was effective at low concentrations. A minimum of 20 to 40 ng of a ninhydrin-reactive compound purified using RP-HPLC caused visible inhibition in assays. Activity was heat stable and unaffected by amino acids, iron, or enzymes known to affect antibiotics of P. agglomerans. Antibiosis was diminished, however, under basic conditions, and with increasing phosphate concentrations at pH 6 and 7. Inhibition was not observed in media containing phosphate concentrations commonly used in antibiosis assays. We propose that E325 suppresses the fire blight pathogen not only by competing for nutrients on the stigma, but by producing an antibiotic specific to E. amylovora. Further work is necessary to substantiate that the compound is produced and active on flower stigmas.

  12. Antibiosis activity of Pantoea agglomerans biocontrol strain E325 against Erwinia amylovora on apple flower stigmas.

    PubMed

    Pusey, P L; Stockwell, V O; Reardon, C L; Smits, T H M; Duffy, B

    2011-10-01

    Pantoea agglomerans E325, the active ingredient in a commercial product for fire blight control, was previously shown in vitro to produce a unique alkaline- and phosphate-sensitive antibiotic specific to Erwinia amylovora. Antibiosis was evaluated as a mode of antagonism on flower stigmas using two antibiosis-deficient mutants. On King's medium B, mutants E325ad1 and E325ad2 have stable smooth-butyrous or hypermucoid colony morphologies, respectively, and the parental strain E325 exhibits phenotypic plasticity with predominantly hypermucoid colonies accompanied by slower-growing, smooth-butyrous colonies. Mutants were tested against E. amylovora on stigmas of detached flowers of crab apple (Malus mandshurica) in growth chambers and apple (Malus domestica) in the orchard. Epiphytic fitness of the antibiosis-negative mutants was similar or greater than the parental strain as determined by relative area under the population curve (RAUPC). In laboratory and orchard trials, both mutants had significantly lower inhibitory activity against the pathogen (i.e., less reduction of E. amylovora RAUPC) compared with the parental strain. E325 and the mutants caused similar decreases in pH in a broth medium, indicating that acidification, which was previously reported as a possible mechanism of pathogen inhibition on stigmas, is not directly related to antibiosis. In this study we provide the first evidence for E325 antibiosis involved in E. amylovora growth suppression on apple flower stigmas.

  13. Development of species-, strain- and antibiotic biosynthesis-specific quantitative PCR assays for Pantoea agglomerans as tools for biocontrol monitoring.

    PubMed

    Braun-Kiewnick, Andrea; Lehmann, Andreas; Rezzonico, Fabio; Wend, Chris; Smits, Theo H M; Duffy, Brion

    2012-09-01

    Pantoea agglomerans is a cosmopolitan plant epiphytic bacterium that includes some of the most effective biological antagonists against the fire blight pathogen Erwinia amylovora, a major threat to pome fruit production worldwide. Strain E325 is commercially available as Bloomtime Biological™ in the USA and Canada. New quantitative PCR (qPCR) assays were developed for species- and strain -specific detection in the environment, and for detection of indigenous strains carrying the biocontrol antibacterial peptide biosynthesis gene paaA. The qPCR assays were highly specific, efficient and sensitive, detecting fewer than three cells per reaction or 700 colony forming units per flower, respectively. The qPCR assays were tested on field samples, giving first indications to the incidence of P. agglomerans E325 related strains, total P. agglomerans and pantocin A producing bacteria in commercial orchards. These assays will facilitate monitoring the environmental behavior of biocontrol P. agglomerans after orchard application for disease protection, proprietary strain-tracking, and streamlined screening for discovery of new biocontrol strains.

  14. Production of the biocontrol agent Pantoea agglomerans strain CPA-2 using commercial products and by-products.

    PubMed

    Costa, E; Teixidó, N; Usall, J; Atarés, E; Viñas, I

    2001-08-01

    The aim of this paper was to find the nitrogen and carbon sources that provide maximum biomass production of strain CPA-2 of the biocontrol agent Pantoea agglomerans and minimum cost of media, whilst maintaining biocontrol efficacy. To reduce the cost of media, commercial products and by-products were tested. P. agglomerans can be produced using a combination of nitrogen sources such as yeast extract (5 g l(-1)) and dry beer yeast (10 g l(-1)) with inexpensive carbohydrates such as sucrose (10 g l(-1)) and molasses (20 g l(-1)), respectively, maintaining the efficacy of the biocontrol agent against Penicillium digitatum and P. italicum on oranges. The results obtained in this study could be used to provide a reliable basis for a scale-up of this fermentation process to an industrial level.

  15. Colonization of Wheat Roots by an Exopolysaccharide-Producing Pantoea agglomerans Strain and Its Effect on Rhizosphere Soil Aggregation

    PubMed Central

    Amellal, N.; Burtin, G.; Bartoli, F.; Heulin, T.

    1998-01-01

    The effect of bacterial secretion of an exopolysaccharide (EPS) on rhizosphere soil physical properties was investigated by inoculating strain NAS206, which was isolated from the rhizosphere of wheat (Triticum durum L.) growing in a Moroccan vertisol and was identified as Pantoea aglomerans. Phenotypic identification of this strain with the Biotype-100 system was confirmed by amplified ribosomal DNA restriction analysis. After inoculation of wheat seedlings with strain NAS206, colonization increased at the rhizoplane and in root-adhering soil (RAS) but not in bulk soil. Colonization further increased under relatively dry conditions (20% soil water content; matric potential, −0.55 MPa). By means of genetic fingerprinting using enterobacterial repetitive intergenic consensus PCR, we were able to verify that colonies counted as strain NAS206 on agar plates descended from inoculated strain NAS206. The intense colonization of the wheat rhizosphere by these EPS-producing bacteria was associated with significant soil aggregation, as shown by increased ratios of RAS dry mass to root tissue (RT) dry mass (RAS/RT) and the improved water stability of adhering soil aggregates. The maximum effect of strain NAS206 on both the RAS/RT ratio and aggregate stability was measured at 24% average soil water content (matric potential, −0.20 MPa). Inoculated strain NAS206 improved RAS macroporosity (pore diameter, 10 to 30 μm) compared to the noninoculated control, particularly when the soil was nearly water saturated (matric potential, −0.05 MPa). Our results suggest that P. agglomerans NAS206 can play an important role in the regulation of the water content (excess or deficit) of the rhizosphere of wheat by improving soil aggregation. PMID:9758793

  16. Survival of Pantoea agglomerans E325 as fire blight biocontrol agent when osmoadapted in high-saline medium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pantoea agglomerans strain E325 is available commercially as the active ingredient in a freeze-dried product (Bloomtime FDTM) of Northwest Agricultural Products (NAP) for biological control of fire blight. Osmoadaptation, which involves the combination of Pantoea agglomerans strain E325 is available...

  17. Assessment of the relevance of the antibiotic 2-amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine from Pantoea agglomerans biological control strains against bacterial plant pathogens

    PubMed Central

    Sammer, Ulrike F; Reiher, Katharina; Spiteller, Dieter; Wensing, Annette; Völksch, Beate

    2012-01-01

    The epiphyte Pantoea agglomerans 48b/90 (Pa48b) is a promising biocontrol strain against economically important bacterial pathogens such as Erwinia amylovora. Strain Pa48b produces the broad-spectrum antibiotic 2-amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine (APV) in a temperature-dependent manner. An APV-negative mutant still suppressed the E. amylovora population and fire blight disease symptoms in apple blossom experiments under greenhouse conditions, but was inferior to the Pa48b wild-type indicating the influence of APV in the antagonism. In plant experiments with the soybean pathogen Pseudomonas syringae pv. glycinea both, Pa48b and the APV-negative mutant, successfully suppressed the pathogen. Our results demonstrate that the P. agglomerans strain Pa48b is an efficient biocontrol organism against plant pathogens, and we prove its ability for fast colonization of plant surfaces over a wide temperature range. PMID:23233458

  18. Draft Genome Sequence of a Copper-Resistant Marine Bacterium, Pantoea agglomerans Strain LMAE-2, a Bacterial Strain with Potential Use in Bioremediation.

    PubMed

    Corsini, Gino; Valdés, Natalia; Pradel, Paulina; Tello, Mario; Cottet, Luis; Muiño, Laura; Karahanian, Eduardo; Castillo, Antonio; Gonzalez, Alex R

    2016-06-16

    Pantoea agglomerans LMAE-2 was isolated from seabed sediment moderately contaminated with Cu(2+) Here, we report its draft genome sequence, which has a size of 4.98 Mb. The presence of cop genes related with copper homeostasis in its genome may explain the resistance and strengthen its potential for use as bioremediation agent.

  19. Draft Genome Sequence of a Copper-Resistant Marine Bacterium, Pantoea agglomerans Strain LMAE-2, a Bacterial Strain with Potential Use in Bioremediation

    PubMed Central

    Corsini, Gino; Valdés, Natalia; Pradel, Paulina; Tello, Mario; Cottet, Luis; Karahanian, Eduardo; Castillo, Antonio

    2016-01-01

    Pantoea agglomerans LMAE-2 was isolated from seabed sediment moderately contaminated with Cu2+. Here, we report its draft genome sequence, which has a size of 4.98 Mb. The presence of cop genes related with copper homeostasis in its genome may explain the resistance and strengthen its potential for use as bioremediation agent. PMID:27313292

  20. [SEROLOGICAL PROPERTIES AND BIOLOGICAL ACTIVITY OF PANTOEA AGGLOMERANS LIPOPOLYSACCHARIDES].

    PubMed

    Bulygina, T V; Yakovleva, L M; Brovarska, O S; Varbanets, L D

    2015-01-01

    The serological and phytotoxic properties of lipopolysaccharide (LPS) of plant pathogens--Pantoea agglomerans were studied. It is known that the thin variations in the structure of the O-specific polysaccharides determining serological specificity of gram- negative bacteria and used as a molecular basis of serological classification schemes. For P. agglomerans still does not exist a classification scheme based on serology specificity of their LPS. The results of cross serological tests demonstrate immunochemical heterogeneity of species P agglomerans. Only three strains of the 8488, 8490 and 7969 according to the agglutination of O-antigens and direct hemagglutination and inhibition direct hemagglutination can be attributed to a single serogroup. Other strains--each separate group, although some have a relationship. Compared with control plants under the influence of seed treatment of LPS in plants may be reduced, and in some cases increased root length, height and weight sprout, depending on the strain from which the selected LPS. Dive seedlings of tomatoes in the solutions of the studied preparations FSC caused the loss, and after some time, restore turgor.

  1. Pantoea agglomerans in Immunodeficient Patients with Different Respiratory Symptoms

    PubMed Central

    Flores Popoca, Erika Odilia; Miranda García, Maximino; Romero Figueroa, Socorro; Mendoza Medellín, Aurelio; Sandoval Trujillo, Horacio; Silva Rojas, Hilda Victoria; Ramírez Durán, Ninfa

    2012-01-01

    The aim of this paper was to determine in 32 patients from 4 different Mexican hospitals the frequency of opportunistic bacteria in the 2010 to 2011 time period. The patients were divided in 4 groups. Group 1 included 21 HIV positive patients with acute respiratory syndrome. Four HIV positive patients with tuberculosis symptoms were included in Group 2; two patients with tuberculosis symptoms and one asymptomatic person formed Group 3. Reference Group 4 included 4 patients from whom 4 strains of Mycobacterium spp. had been reported. The strains were isolated and identified by 16S rRNA gene amplification, API 20E and 50CH, biochemical test, and antibiotic sensitivity. The strains found were 10 Pantoea agglomerans, 6 Mycobacterium spp., 6 Pseudomonas spp. and 10 strains of normal floral species: Thermoactinomycetes bacterium (1), Enterococcus faecium (2), Bacillus licheniformis (1), Lactobacillus rhamnosus (2), Streptococcus oralis (2), Streptococcus anginosus (1), and Enterobacter hormaechei (1). PMID:22619600

  2. Pantoea agglomerans, a Plant Pathogen Causing Human Disease▿

    PubMed Central

    Cruz, Andrea T.; Cazacu, Andreea C.; Allen, Coburn H.

    2007-01-01

    We present 53 pediatric cases of Pantoea agglomerans infections cultured from normally sterile sites in patients seen at a children's hospital over 6 years. Isolates included 23 from the bloodstream, 14 from abscesses, 10 from joints/bones, 4 from the urinary tract, and 1 each from the peritoneum and the thorax. P. agglomerans was most associated with penetrating trauma by vegetative material and catheter-related bacteremia. PMID:17442803

  3. Controlled release of Pantoea agglomerans E325 for biocontrol of fire blight

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microencapsulation and controlled release of Pantoea agglomerans strain E325 (E325), which is an antagonist to bacterial pathogen (Erwinia amylovora) of fire blight, a devastating disease of apple and pear, have been investigated. Uniform core-shell alginate microcapsules (AMCs), 60-300 µm in diamet...

  4. The combination Enterobacter agglomerans is to be cited as Enterobacter agglomerans (Beijerinck 1888) Ewing and Fife 1972 and the combination Pantoea agglomerans is to be cited as Pantoea agglomerans (Beijerinck 1888) Gavini et al. 1989. Opinion 90. Judicial Commission of the International Committee on Systematics of Prokaryotes.

    PubMed

    Tindall, B J

    2014-10-01

    The Judicial Commission affirms that, according to information presented to it, the combination Enterobacter agglomerans is to be cited as Enterobacter agglomerans (Beijerinck 1888) Ewing and Fife 1972 and the combination Pantoea agglomerans is to be cited as Pantoea agglomerans (Beijerinck 1888) Gavini et al. 1989.

  5. Pantoea agglomerans: a mysterious bacterium of evil and good. Part IV. Beneficial effects.

    PubMed

    Dutkiewicz, Jacek; Mackiewicz, Barbara; Lemieszek, Marta Kinga; Golec, Marcin; Milanowski, Janusz

    2016-06-02

    a biocontrol agent permits the decrease of pesticide doses, being a healthy and environmental-friendly procedure. The application of the preparations of this bacterium efficiently protects the stored pome, stone and citrus fruits against invasion of moulds. P. agglomerans strains associated with both rhizosphere and plant tissues (as endophytes) efficiently promote the growth of many plants, including rice and wheat, which are the staple food for the majority of mankind. The promotion mechanisms are diverse and include fixation of atmospheric nitrogen, production of phytohormones, as well as degradation of phytate and phosphate solubilizing which makes the soil phosphorus available for plants. Accordingly, P. agglomerans is regarded as an ideal candidate for an environmental-friendly bioinoculant replacing chemical fertilizers. It has been documented that the Pantoea strains show biodegradation activity on various chemical pollutants of soil and water, including petroleum hydrocarbons and toxic metals. P. agglomerans prevents the penetration of harmful industrial contaminants into deeper parts of soil by biofilm formation, and has an ability to produce hydrogen from waste. Thus, this bacterium appears as a valuable bioremediator which, in some cases, may be acquired as a cheap form of energy. In conclusion, in spite of the proven pathologic role of P. agglomerans in causing occupational diseases of allergic and/or immunotoxic background and accidental infections, the beneficial traits of this species, and of related species of Pantoea genus, are of great value for potential use in many areas of biotechnology. Hence, any restrictions on the use of these organisms and their products should be declined, providing safety precautions at work with the Pantoea biopreparations are maintained.

  6. Evidence that antibiotic of Pantoea agglomerans E325 is produced and active against Erwinia amylovora on stigmas of pomaceous blossoms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pantoea agglomerans strain E325, the active ingredient in a commercial product for fire blight, previously was shown to produce a unique pH-sensitive inhibitor in vitro that is specific to E. amylovora. To evaluate antibiosis as a mode of antagonism of E325, Tn5 mutagenesis was used to generate...

  7. Potential of osmoadaptation for improving Pantoea agglomerans E325 as biocontrol agent for fire blight of apple and pear

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pantoea agglomerans biocontrol strain E325 is the active ingredient in a commercial product for fire blight, a destructive disease of apple and pear initiated by Erwinia amylovora in flowers. Osmoadaptation, involving the combination of saline osmotic stress and osmolyte amendment to growth media, w...

  8. Pantoea agglomerans: a mysterious bacterium of evil and good. Part III. Deleterious effects: infections of humans, animals and plants.

    PubMed

    Dutkiewicz, Jacek; Mackiewicz, Barbara; Kinga Lemieszek, Marta; Golec, Marcin; Milanowski, Janusz

    2016-06-02

    Pantoea agglomerans, a bacterium associated with plants, is not an obligate infectious agent in humans. However, it could be a cause of opportunistic human infections, mostly by wound infection with plant material, or as a hospital-acquired infection, mostly in immunocompromised individuals. Wound infection with P. agglomerans usually follow piercing or laceration of skin with a plant thorn, wooden splinter or other plant material and subsequent inoculation of the plant-residing bacteria, mostly during performing of agricultural occupations and gardening, or children playing. Septic arthritis or synovitis appears as a common clinical outcome of exogenous infection with P. agglomerans, others include endophthalmitis, periostitis, endocarditis and osteomyelitis. Another major reason for clinical infection with P. agglomerans is exposure of hospitalized, often immunodeficient individuals to medical equipment or fluids contaminated with this bacterium. Epidemics of nosocomial septicemia with fatal cases have been described in several countries, both in adult and paediatric patients. In most cases, however, the clinical course of the hospital-acquired disease was mild and application of the proper antibiotic treatment led to full recovery. Compared to humans, there are only few reports on infectious diseases caused by Pantoea agglomerans in vertebrate animals. This species has been identified as a possible cause of equine abortion and placentitis and a haemorrhagic disease in dolphin fish (Coryphaena hippurus). P. agglomerans strains occur commonly, usually as symbionts, in insects and other arthropods. Pantoea agglomerans usually occurs in plants as an epi- or endophytic symbiont, often as mutualist. Nevertheless, this species has also also been identified as a cause of diseases in a range of cultivable plants, such as cotton, sweet onion, rice, maize, sorghum, bamboo, walnut, an ornamental plant called Chinese taro (Alocasia cucullata), and a grass called onion couch

  9. Sugarcane Growth Promotion by the Endophytic Bacterium Pantoea agglomerans 33.1

    PubMed Central

    Rossetto, P. B.; Ferreira, A.; Tsui, S.; Lacava, P. T.; Mondin, M.; Azevedo, J. L.; Pizzirani-Kleiner, A. A.

    2012-01-01

    The promotion of sugarcane growth by the endophytic Pantoea agglomerans strain 33.1 was studied under gnotobiotic and greenhouse conditions. The green fluorescent protein (GFP)-tagged strain P. agglomerans 33.1::pNKGFP was monitored in vitro in sugarcane plants by microscopy, reisolation, and quantitative PCR (qPCR). Using qPCR and reisolation 4 and 15 days after inoculation, we observed that GFP-tagged strains reached similar density levels both in the rhizosphere and inside the roots and aerial plant tissues. Microscopic analysis was performed at 5, 10, and 18 days after inoculation. Under greenhouse conditions, P. agglomerans 33.1-inoculated sugarcane plants presented more dry mass 30 days after inoculation. Cross-colonization was confirmed by reisolation of the GFP-tagged strain. These data demonstrate that 33.1::pNKGFP is a superior colonizer of sugarcane due to its ability to colonize a number of different plant parts. The growth promotion observed in colonized plants may be related to the ability of P. agglomerans 33.1 to synthesize indoleacetic acid and solubilize phosphate. Additionally, this strain may trigger chitinase and cellulase production by plant roots, suggesting the induction of a plant defense system. However, levels of indigenous bacterial colonization did not vary between inoculated and noninoculated sugarcane plants under greenhouse conditions, suggesting that the presence of P. agglomerans 33.1 has no effect on these communities. In this study, different techniques were used to monitor 33.1::pNKGFP during sugarcane cross-colonization, and our results suggested that this plant growth promoter could be used with other crops. The interaction between sugarcane and P. agglomerans 33.1 has important benefits that promote the plant's growth and fitness. PMID:22865062

  10. Endophytic population of Pantoea agglomerans in citrus plants and development of a cloning vector for endophytes.

    PubMed

    Andreote, Fernando D; Rossetto, Priscilla B; Souza, Leonardo C A; Marcon, Joelma; Maccheroni, Walter; Azevedo, João L; Araújo, Welington L

    2008-10-01

    Harmless bacteria inhabiting inner plant tissues are termed endophytes. Population fluctuations in the endophytic bacterium Pantoea agglomerans associated with two species of field cultured citrus plants were monitored over a two-year period. The results demonstrated that populations of P. agglomerans fluctuated in Citrus reticulata but not C. sinensis. A cryptic plasmid pPA3.0 (2.9 kb) was identified in 35 out of 44 endophytic isolates of P. agglomerans and was subsequently sequenced. The origins of replication were identified and nine out of 18 open reading frames (ORFs) revealed homology with described proteins. Notably, two ORFs were related to cellular transport systems and plasmid maintenance. Plasmid pPA3.0 was cloned and the gfp gene inserted to generate the pPAGFP vector. The vector was introduced into P. agglomerans isolates and revealed stability was dependent on the isolate genotype, ninety-percent stability values were reached after 60 hours of bacterial cultivation in most evaluated isolates. In order to definitively establish P. agglomerans as an endophyte, the non-transformed bacterium was reintroduced into in vitro cultivated seedlings and the density of inner tissue colonization in inoculated plants was estimated by bacterium re-isolation, while the tissue niches preferred by the bacterium were investigated by scanning electronic microscopy (SEM). Cells from P. agglomerans (strain ARB18) at similar densities were re-isolated from roots, stems and leaves and colonization of parenchyma and xylem tissues were observed. Data suggested that P. agglomerans is a ubiquitous citrus endophyte harboring cryptic plasmids. These characteristics suggest the potential to use the bacterium as a vehicle to introduce new genes in host plants via endophytic bacterial transformation.

  11. Unusual causes of peritonitis in a peritoneal dialysis patient: Alcaligenes faecalis and Pantoea agglomerans.

    PubMed

    Kahveci, Arzu; Asicioglu, Ebru; Tigen, Elif; Ari, Elif; Arikan, Hakki; Odabasi, Zekaver; Ozener, Cetin

    2011-04-10

    An 87 -year-old female who was undergoing peritoneal dialysis presented with peritonitis caused by Alcaligenes faecalis and Pantoea agglomerans in consecutive years. With the following report we discuss the importance of these unusual microorganisms in peritoneal dialysis patients.

  12. Degradation of myo-inositol hexakisphosphate by a phytate-degrading enzyme from Pantoea agglomerans.

    PubMed

    Greiner, Ralf

    2004-11-01

    High-pressure liquid chromatography (HPLC) analysis established myo-inositol pentakisphosphate as the final product of phytate dephosphorylation by the phytate-degrading enzyme from Pantoea agglomerans. Neither product inhibition by phosphate nor inactivation of the Pantoea enzyme during the incubation period were responsible for the limited phytate hydrolysis as shown by addition of phytate-degrading enzyme and phytate, respectively, after the observed stop of enzymatic phytate degradation. In additon, the Pantoea enzyme did not possess activity toward the purified myo-inositol pentakisphosphate. Using a combination of High-Performance Ion Chromatography (HPIC) analysis and kinetic studies, the nature of the generated myo-inositol pentakisphosphate was established. The data demonstrate that the phytate-degrading enzyme from Pantoea agglomerans dephosphorylates myo-inositol hexakisphosphate in a stereospecific way to finally D-myo-inositol(1,2,4,5,6)pentakisphosphate.

  13. Isolation and characterization of plant growth promoting traits of a rhizobacteria: Pantoea agglomerans lma2.

    PubMed

    Silini-Chérif, H; Silini, A; Ghoul, M; Yadav, S

    2012-03-15

    The use of microbial technology in agriculture is expanding quickly with the identification of new bacterial strains which are more effective in promoting the growth of plants. The rhizobacteria that promote the growth of plants can have a positive effect on the productivity of crops especially when subjected to salt stress. A nitrogen-fixing bacterium was isolated from the wheat rhizosphere of an arid region. The strain was identified on the basis of tests API20E and 16S rRNA sequencing, as Pantoea agglomerans lma2. This strain degraded several carbon sources: sugars (fructose, ribose, dextrin, salicin...), lipids (lecithin, tributyrin and tween 80), proteins (gelatin, casein), grew on KCN and could grow from pH 4 to 8 and had an optimum at pH 7. The growth temperature showed a maximum at 30 degrees C and the bacteria could tolerate from 4 to 41 degrees C and the growth rate was higher when the NaCl concentration was between 100 and 300 mM. The performance of activities enhancing the growth of plants of P. agglomerans lma2 was significantly better in the presence of salt. Rates of Indole Acetic Acid (IAA), siderophores production and solubilization of phosphate increased between 100 and 400 mM NaCl compared to the control without salt. The maximum values were saved to 300 mM for the production of siderophores (18.32%) and solubilization of phosphate (1061.49 microg mL(-1)) and 100 mM for the production of IAA (161 microg mL(-1)). A significant correlation existed between these three activities. These results showed that P. agglomerans lma2 with its Plant Growth Promoting Rhizobacteria (PGPR) and halophilic properties could constitute a good fertilizer in arid and saline zone.

  14. Identification of Candida tropicalis BH-6 and synergistic effect with Pantoea agglomerans BH-18 on hydrogen production in marine culture.

    PubMed

    Zhu, Daling; Ma, Yingchao; Wang, Guangce; Pan, Guanghua

    2015-03-01

    A marine yeast was isolated from mangrove sludge and named Candida tropicalis BH-6. The optimum temperature and the initial pH value for growth of the isolated strain were 37 °C and 5.0, respectively. The strain had high salt tolerance and could survive at NaCl concentrations of 0-6 %. Additionally, the yield of hydrogen production by C. tropicalis BH-6 was only 66.30 ml/l. However, when the yeast was mixed with Pantoea agglomerans BH-18, hydrogen production increased significantly to a maximum of 1707.5 ml/l, which was 36.94 and 247.54 % higher than the monoculture of P. agglomerans BH-18 and C. tropicalis BH-6, respectively. Taken together, these results revealed that in mixed culture, the yeast strain isolated from the same ecosystem as P. agglomerans BH-18 likely consumed the organic acids produced by fermentation, thus eliminating the factor inhibiting hydrogen production by P. agglomerans BH-18. As a result, the yield of hydrogen production during mixed culture increased significantly.

  15. New Blue Pigment Produced by Pantoea agglomerans and Its Production Characteristics at Various Temperatures ▿

    PubMed Central

    Fujikawa, Hiroshi; Akimoto, Ryo

    2011-01-01

    A bacterium capable of producing a deep blue pigment was isolated from the environment and identified as Pantoea agglomerans. The pigment production characteristics of the bacterium under various conditions were studied. The optimal agar plate ingredients for pigment production by the bacterium were first studied: the optimal ingredients were 5 g/liter glucose, 10 g/liter tryptic soy broth, and 40 g/liter glycerol at pH 6.4. Bacterial cells grew on the agar plate during the incubation, while the pigment spread into the agar plate, meaning that it is water soluble. Pigment production was affected by the initial cell density. Namely, at higher initial cell densities ranging from 106.3 to 108.2 CFU/cm2 on the agar plate, faster pigment production was observed, but no blue pigment was produced at a very high initial density of 109.1 CFU/cm2. Thus, the cell population of 108.2 CFU/cm2 was used for subsequent study. Although the bacterium was capable of growing at temperatures above and below 10°C, it could produce the pigment only at temperatures of ≥10°C. Moreover, the pigment production was faster at higher temperatures in the range of 10 to 20°C. Pigment production at various temperature patterns was well described by a new logistic model. These results suggested that the bacterium could be used in the development of a microbial temperature indicator for the low-temperature-storage management of foods and clinical materials. To our knowledge, there is no other P. agglomerans strain capable of producing a blue pigment and the pigment is a new one of microbial origin. PMID:20971865

  16. Antibiosis and acidification by Panoea agglomerans strain E325 may contribute to suppression of Erwinia amylovora

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pantoea agglomerans strain E325, a commercially-available antagonist for fire blight of apple and pear, was originally selected through broad screening based on suppression of Erwinia amylovora on flower stigmas, but specific mechanisms were unknown. Bacterial modification of pH was evaluated as a p...

  17. Draft Genome Assemblies of Enterobacter aerogenes CDC 6003-71, Enterobacter cloacae CDC 442-68, and Pantoea agglomerans UA 0804-01.

    PubMed

    Minogue, T D; Daligault, H E; Davenport, K W; Bishop-Lilly, K A; Bruce, D C; Chain, P S; Coyne, S R; Chertkov, O; Freitas, T; Frey, K G; Jaissle, J; Koroleva, G I; Ladner, J T; Palacios, G F; Redden, C L; Xu, Y; Johnson, S L

    2014-10-23

    The Enterobacteriaceae are environmental and enteric microbes. We sequenced the genomes of two Enterobacter reference strains, E. aerogenes CDC 6003-71 and E. cloacae CDC 442-68, as well as one near neighbor used as an exclusionary reference for diagnostics, Pantoea agglomerans CDC UA0804-01. The genome sizes range from 4.72 to 5.55 Mbp and have G+C contents from 54.6 to 55.1%.

  18. Draft Genome Assemblies of Enterobacter aerogenes CDC 6003-71, Enterobacter cloacae CDC 442-68, and Pantoea agglomerans UA 0804-01

    PubMed Central

    Minogue, T. D.; Daligault, H. E.; Davenport, K. W.; Bishop-Lilly, K. A.; Bruce, D. C.; Chain, P. S.; Coyne, S. R.; Chertkov, O.; Freitas, T.; Frey, K. G.; Jaissle, J.; Koroleva, G. I.; Ladner, J. T.; Palacios, G. F.; Redden, C. L.; Xu, Y.

    2014-01-01

    The Enterobacteriaceae are environmental and enteric microbes. We sequenced the genomes of two Enterobacter reference strains, E. aerogenes CDC 6003-71 and E. cloacae CDC 442-68, as well as one near neighbor used as an exclusionary reference for diagnostics, Pantoea agglomerans CDC UA0804-01. The genome sizes range from 4.72 to 5.55 Mbp and have G+C contents from 54.6 to 55.1%. PMID:25342683

  19. Controlled release of Pantoea agglomerans E325 for biocontrol of fire blight disease of apple.

    PubMed

    Kim, In-Yong; Pusey, Paul Lawrence; Zhao, Youfu; Korban, Schuyler S; Choi, Hyungsoo; Kim, Kyekyoon Kevin

    2012-07-10

    Microencapsulation and controlled release of the biocontrol agent Pantoea agglomerans strain E325 (E325), an antagonist to the bacterial plant pathogen Erwinia amylovora that causes fire blight, a devastating disease of apple and pear, have been investigated. Uniform core-shell alginate microcapsules (AMCs), 60-300 μm in diameter, were fabricated to encapsulate E325 within the core, along with nutrients, to preserve viability and promote proliferation. Controlled release of E325 was achieved by separately adjusting alginate concentrations in the shell and core solutions, and by modifying the AMC size. Viability of E325 was monitored via fluorescent staining, revealing either lack of or minimal stress during or after encapsulation. Proliferation of E325 within AMCs, followed by their subsequent release, and colonization activities within confines of apple flowers were studied under different encapsulation conditions using rfp-labeled E325 to obtain highly promising results. This study provided a 'proof of concept' of the successful use of a microencapsulated biocontrol agent, E325, against E. amylovora, and could serve as a model for further studies on the development of effective plant disease management strategies.

  20. Absence of lysogeny in wild populations of Erwinia amylovora and Pantoea agglomerans.

    PubMed

    Roach, Dwayne R; Sjaarda, David R; Sjaarda, Calvin P; Ayala, Carlos Juarez; Howcroft, Brittany; Castle, Alan J; Svircev, Antonet M

    2015-05-01

    Lytic bacteriophages are in development as biological control agents for the prevention of fire blight disease caused by Erwinia amylovora. Temperate phages should be excluded as biologicals since lysogeny produces the dual risks of host resistance to phage attack and the transduction of virulence determinants between bacteria. The extent of lysogeny was estimated in wild populations of E. amylovora and Pantoea agglomerans with real-time polymerase chain reaction primers developed to detect E. amylovora phages belonging to the Myoviridae and Podoviridae families. Pantoea agglomerans, an orchard epiphyte, is easily infected by Erwinia spp. phages, and it serves as a carrier in the development of the phage-mediated biological control agent. Screening of 161 E. amylovora isolates from 16 distinct geographical areas in North America, Europe, North Africa and New Zealand and 82 P. agglomerans isolates from southern Ontario, Canada showed that none possessed prophage. Unstable phage resistant clones or lysogens were produced under laboratory conditions. Additionally, a stable lysogen was recovered from infection of bacterial isolate Ea110R with Podoviridae phage ΦEa35-20. These laboratory observations suggested that while lysogeny is possible in E. amylovora, it is rare or absent in natural populations, and there is a minimal risk associated with lysogenic conversion and transduction by Erwinia spp. phages.

  1. Absence of lysogeny in wild populations of Erwinia amylovora and Pantoea agglomerans

    PubMed Central

    Roach, Dwayne R; Sjaarda, David R; Sjaarda, Calvin P; Ayala, Carlos Juarez; Howcroft, Brittany; Castle, Alan J; Svircev, Antonet M

    2015-01-01

    Lytic bacteriophages are in development as biological control agents for the prevention of fire blight disease caused by Erwinia amylovora. Temperate phages should be excluded as biologicals since lysogeny produces the dual risks of host resistance to phage attack and the transduction of virulence determinants between bacteria. The extent of lysogeny was estimated in wild populations of E. amylovora and Pantoea agglomerans with real–time polymerase chain reaction primers developed to detect E. amylovora phages belonging to the Myoviridae and Podoviridae families. Pantoea agglomerans, an orchard epiphyte, is easily infected by Erwinia spp. phages, and it serves as a carrier in the development of the phage-mediated biological control agent. Screening of 161 E. amylovora isolates from 16 distinct geographical areas in North America, Europe, North Africa and New Zealand and 82 P. agglomerans isolates from southern Ontario, Canada showed that none possessed prophage. Unstable phage resistant clones or lysogens were produced under laboratory conditions. Additionally, a stable lysogen was recovered from infection of bacterial isolate Ea110R with Podoviridae phage ΦEa35-20. These laboratory observations suggested that while lysogeny is possible in E. amylovora, it is rare or absent in natural populations, and there is a minimal risk associated with lysogenic conversion and transduction by Erwinia spp. phages. PMID:25678125

  2. 2-Amino-3-(Oxirane-2,3-Dicarboxamido)-Propanoyl-Valine, an Effective Peptide Antibiotic from the Epiphyte Pantoea agglomerans 48b/90 ▿

    PubMed Central

    Sammer, Ulrike F.; Völksch, Beate; Möllmann, Ute; Schmidtke, Michaela; Spiteller, Peter; Spiteller, Michael; Spiteller, Dieter

    2009-01-01

    The epiphyte Pantoea agglomerans 48b/90, which has been isolated from soybean leaves, belongs to the Enterobacteriaceae, as does the plant pathogen Erwinia amylovora, which causes fire blight on rosaceous plants such as apples and leads to severe economic losses. Since P. agglomerans efficiently antagonizes phytopathogenic bacteria, the P. agglomerans strain C9-1 is used as a biocontrol agent (BlightBan C9-1). Here we describe the bioassay-guided isolation of a peptide antibiotic that is highly active against the plant pathogen E. amylovora and pathovars of Pseudomonas syringae, and we elucidate its structure. Bioassay-guided fractionation using anion-exchange chromatography followed by hydrophobic interaction liquid chromatography yielded the bioactive, highly polar antibiotic. The compound was identified as 2-amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine by using high-resolution electrospray ionization mass spectrometry and nuclear magnetic resonance techniques. This peptide was found to be produced by three of the nine P. agglomerans strains analyzed. Notably, the biocontrol strain P. agglomerans C9-1 also produces 2-amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine. Previously, 2-amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine has been characterized only from Serratia plymuthica. 2-Amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine has been shown to inhibit the growth of the human pathogen Candida albicans efficiently, but its involvement in the defense of epiphytes against phytopathogenic bacteria has not been investigated so far. PMID:19820144

  3. [Seven cases of port-a-cath contamination caused by Pantoea agglomerans in the Oncological Service of Iseo Hospital, Brescia (Italy)].

    PubMed

    Izzo, Ilaria; Lania, Donatella; Castro, Antonino; Lanzini, Fernanda; Bella, Daniele; Pagani, Adriano; Colombini, Paolo

    2014-06-01

    Pantoea agglomerans, a gram negative bacillus in the Enterobacteriaceae family, has been isolated from feculent material, plants and soil. Soft tissue and bone-joint infections due to P. agglomerans following penetrating trauma by vegetation and bacteraemia in association with intravenous fluid, total parenteral nutrition, blood products and anaesthetic agent contamination have been reported. Between October 2009 and January 2010 seven cases of port a cath contamination caused by P. agglomerans were observed in the Oncological Service of our hospital. All patients presented with septic fever after heparinization of the central venous catheter. 5/7 patients were female; mean age was 67 years (range 58-75). 6/7 patients were affected by colorectal adenocarcinoma, 1/7 by mammarian cancer. Mean time from CVC insertion was 23.8 months (range 13-42) at the time of fever. In three cases, port a cath was removed following the oncologist prescription. P. agglomerans was isolated from the catheter tip in one case and from CVC blood culture in 6-7 cases. In all cases peripheral blood cultures were negative. Patients were treated with ciprofloxacin lock therapy and systemic therapy (per os), obtaining negative cultures from port a cath. Notwithstanding the absence of isolation of Pantoea strains from environmental cultures, after educational intervention, which underlined some faulty procedures in CVC management, no further cases were observed.

  4. Biosynthesis of selenium nanoparticles by Pantoea agglomerans and their antioxidant activity

    NASA Astrophysics Data System (ADS)

    Torres, S. K.; Campos, V. L.; León, C. G.; Rodríguez-Llamazares, S. M.; Rojas, S. M.; González, M.; Smith, C.; Mondaca, M. A.

    2012-11-01

    The bio-reduction of selenite (Se (IV)) generates nanoparticles with sizes ranging between 30 and 300 nm. Biologic properties of Se nanoparticles, e.g., antioxidant activity, are dependent on the nanoparticle size; smaller particles have greater activity. In this study, the bio-reduction of selenite by Pantoea agglomerans strain UC-32 under aerobic conditions and room temperature to produce bioactive Se nanoparticles smaller than 100 nm was demonstrated. Isolation and purification of the nanoparticles was performed by alkaline lysis. These purified nanoparticles were stabilized with l-cysteine (4 mM). The visualization and characterization of nanoparticles were performed by transmission electron microscopy, energy dispersive X-ray spectroscopy, and scanning electron microscopy. The antioxidant activity of nanoparticles was determined by production of reactive oxygen species using human umbilical vein endothelial cells. Transmission electron microscopy images showed the accumulation of spherical selenium nanoparticles as intracellular and extracellular deposits. The size of Se nanoparticles varied with incubation time. Amorphous Se nanoparticles with size in the order of 100 nm were obtained before 24 h of incubation; but, at 24 h of incubation, the size of the majority of the nanoparticles was in the desirable order of 100 nm and they were not aggregated. Energy dispersive spectroscopy spectra indicated that nanoparticles were composed entirely of selenium. Antioxidant activity of stabilized selenium nanoparticles demonstrated high antioxidant activity when compared to selenite and selenium nanoparticles without stabilization. Stabilized biologically synthetized selenium (0) nanoparticles with size less than 100 nm have a potential application as a food additive with antioxidant properties relevant to human health.

  5. Outbreak of Pantoea agglomerans Bloodstream Infections at an Oncology Clinic-Illinois, 2012-2013.

    PubMed

    Yablon, Brian R; Dantes, Raymund; Tsai, Victoria; Lim, Rachel; Moulton-Meissner, Heather; Arduino, Matthew; Jensen, Bette; Patel, Megan Toth; Vernon, Michael O; Grant-Greene, Yoran; Christiansen, Demian; Conover, Craig; Kallen, Alexander; Guh, Alice Y

    2017-03-01

    OBJECTIVE To determine the source of a healthcare-associated outbreak of Pantoea agglomerans bloodstream infections. DESIGN Epidemiologic investigation of the outbreak. SETTING Oncology clinic (clinic A). METHODS Cases were defined as Pantoea isolation from blood or catheter tip cultures of clinic A patients during July 2012-May 2013. Clinic A medical charts and laboratory records were reviewed; infection prevention practices and the facility's water system were evaluated. Environmental samples were collected for culture. Clinical and environmental P. agglomerans isolates were compared using pulsed-field gel electrophoresis. RESULTS Twelve cases were identified; median (range) age was 65 (41-78) years. All patients had malignant tumors and had received infusions at clinic A. Deficiencies in parenteral medication preparation and handling were identified (eg, placing infusates near sinks with potential for splash-back contamination). Facility inspection revealed substantial dead-end water piping and inadequate chlorine residual in tap water from multiple sinks, including the pharmacy clean room sink. P. agglomerans was isolated from composite surface swabs of 7 sinks and an ice machine; the pharmacy clean room sink isolate was indistinguishable by pulsed-field gel electrophoresis from 7 of 9 available patient isolates. CONCLUSIONS Exposure of locally prepared infusates to a contaminated pharmacy sink caused the outbreak. Improvements in parenteral medication preparation, including moving chemotherapy preparation offsite, along with terminal sink cleaning and water system remediation ended the outbreak. Greater awareness of recommended medication preparation and handling practices as well as further efforts to better define the contribution of contaminated sinks and plumbing deficiencies to healthcare-associated infections are needed. Infect Control Hosp Epidemiol 2017;38:314-319.

  6. Rhizosphere competent Pantoea agglomerans enhances maize (Zea mays) and chickpea (Cicer arietinum L.) growth, without altering the rhizosphere functional diversity.

    PubMed

    Mishra, Aradhana; Chauhan, Puneet Singh; Chaudhry, Vasvi; Tripathi, Manisha; Nautiyal, Chandra Shekhar

    2011-10-01

    Plant growth promoting Pantoea agglomerans NBRISRM (NBRISRM) was able to produce 60.4 μg/ml indole acetic acid and solubilize 77.5 μg/ml tri-calcium phosphate under in vitro conditions. Addition of 2% NaCl (w/v) in the media induced the IAA production and phosphate solubilization by 11% and 7%, respectively. For evaluating the plant growth promotory effect of NBRISRM inoculation a micro plot trial was conducted using maize and chickpea as host plants. The results revealed significant increase in all growth parameters tested in NBRISRM inoculated maize and chickpea plants, which were further confirmed by higher macronutrients (N, P and K) accumulation as compared to un-inoculated controls. Throughout the growing season of maize and chickpea, rhizosphere population of NBRISRM were in the range 10(7)-10(8) CFU/g soil and competing with 10(7)-10(9) CFU/g soil with heterogeneous bacterial population. Functional richness, diversity, and evenness were found significantly higher in maize rhizosphere as compared to chickpea, whereas NBRISRM inoculation were not able to change it, in both crops as compared to their un-inoculated control. To the best of our knowledge this is first report where we demonstrated the effect of P. agglomerans strain for improving maize and chickpea growth without altering the functional diversity.

  7. Secretion of Anti-Plasmodium Effector Proteins from a Natural Pantoea agglomerans Isolate by Using PelB and HlyA Secretion Signals▿

    PubMed Central

    Bisi, Dawn C.; Lampe, David J.

    2011-01-01

    The insect-vectored disease malaria is a major world health problem. New control strategies are needed to supplement the current use of insecticides and medications. A genetic approach can be used to inhibit development of malaria parasites (Plasmodium spp.) in the mosquito host. We hypothesized that Pantoea agglomerans, a bacterial symbiont of Anopheles mosquitoes, could be engineered to express and secrete anti-Plasmodium effector proteins, a strategy termed paratransgenesis. To this end, plasmids that include the pelB or hlyA secretion signals from the genes of related species (pectate lyase from Erwinia carotovora and hemolysin A from Escherichia coli, respectively) were created and tested for their efficacy in secreting known anti-Plasmodium effector proteins (SM1, anti-Pbs21, and PLA2) in P. agglomerans and E. coli. P. agglomerans successfully secreted HlyA fusions of anti-Pbs21 and PLA2, and these strains are under evaluation for anti-Plasmodium activity in infected mosquitoes. Varied expression and/or secretion of the effector proteins was observed, suggesting that the individual characteristics of a particular effector may require empirical testing of several secretion signals. Importantly, those strains that secreted efficiently grew as well as wild-type strains under laboratory conditions and, thus, may be expected to be competitive with the native microbiota in the environment of the mosquito midgut. PMID:21602368

  8. Secretion of anti-Plasmodium effector proteins from a natural Pantoea agglomerans isolate by using PelB and HlyA secretion signals.

    PubMed

    Bisi, Dawn C; Lampe, David J

    2011-07-01

    The insect-vectored disease malaria is a major world health problem. New control strategies are needed to supplement the current use of insecticides and medications. A genetic approach can be used to inhibit development of malaria parasites (Plasmodium spp.) in the mosquito host. We hypothesized that Pantoea agglomerans, a bacterial symbiont of Anopheles mosquitoes, could be engineered to express and secrete anti-Plasmodium effector proteins, a strategy termed paratransgenesis. To this end, plasmids that include the pelB or hlyA secretion signals from the genes of related species (pectate lyase from Erwinia carotovora and hemolysin A from Escherichia coli, respectively) were created and tested for their efficacy in secreting known anti-Plasmodium effector proteins (SM1, anti-Pbs21, and PLA2) in P. agglomerans and E. coli. P. agglomerans successfully secreted HlyA fusions of anti-Pbs21 and PLA2, and these strains are under evaluation for anti-Plasmodium activity in infected mosquitoes. Varied expression and/or secretion of the effector proteins was observed, suggesting that the individual characteristics of a particular effector may require empirical testing of several secretion signals. Importantly, those strains that secreted efficiently grew as well as wild-type strains under laboratory conditions and, thus, may be expected to be competitive with the native microbiota in the environment of the mosquito midgut.

  9. Biochemical characteristics of Enterobacter agglomerans and related strains found in buckwheat seeds.

    PubMed

    Iimura, K; Hosono, A

    1996-07-01

    Thirty strains of bacteria were randomly isolated and identified from buckwheat seeds. The phenotypic characteristics of these strains agree well with those of the Enterobacter agglomerans-Erwinia herbicola complex. On the basis of the difference in indole production and gas production from D-glucose, the isolates were divided into 3 phenotypic groups, viz. I, II and III. Twenty two strains were in phenotypic group 1, which is negative for indole production and gas production from D-glucose, and resembles Pantoea agglomerans. All six strains in phenotypic group II, which is positive for indole production and negative for gas production from D-glucose, were identified as Erwinia ananas. Two strains in phenotypic group III, which is negative for indole production and positive for gas production from D-glucose, were identified as Rahnella aquatilis.

  10. Differences between Pseudomonas syringae pv. syringae B728a and Pantoea agglomerans BRT98 in Epiphytic and Endophytic Colonization of Leaves

    PubMed Central

    Sabaratnam, Siva; Beattie, Gwyn A.

    2003-01-01

    The leaf colonization strategies of two bacterial strains were investigated. The foliar pathogen Pseudomonas syringae pv. syringae strain B728a and the nonpathogen Pantoea agglomerans strain BRT98 were marked with a green fluorescent protein, and surface (epiphytic) and subsurface (endophytic) sites of bean and maize leaves in the laboratory and the field were monitored to see if populations of these strains developed. The populations were monitored using both fluorescence microscopy and counts of culturable cells recovered from nonsterilized and surface-sterilized leaves. The P. agglomerans strain exclusively colonized epiphytic sites on the two plant species. Under favorable conditions, the P. agglomerans strain formed aggregates that often extended over multiple epidermal cells. The P. syringae pv. syringae strain established epiphytic and endophytic populations on asymptomatic leaves of the two plant species in the field, with most of the P. syringae pv. syringae B728a cells remaining in epiphytic sites of the maize leaves and an increasing number occupying endophytic sites of the bean leaves in the 15-day monitoring period. The epiphytic P. syringae pv. syringae B728a populations appeared to originate primarily from multiplication in surface sites rather than from the movement of cells from subsurface to surface sites. The endophytic P. syringae pv. syringae B728a populations appeared to originate primarily from inward movement through the stomata, with higher levels of multiplication occurring in bean than in maize. A rainstorm involving a high raindrop momentum was associated with rapid growth of the P. agglomerans strain on both plant species and with rapid growth of both the epiphytic and endophytic populations of the P. syringae pv. syringae strain on bean but not with growth of the P. syringae pv. syringae strain on maize. These results demonstrate that the two bacterial strains employed distinct colonization strategies and that the epiphytic and

  11. Diversity of endophytic bacteria from Eucalyptus species seeds and colonization of seedlings by Pantoea agglomerans.

    PubMed

    Ferreira, Anderson; Quecine, Maria Carolina; Lacava, Paulo Teixeira; Oda, Shinitiro; Azevedo, João Lúcio; Araújo, Welington Luiz

    2008-10-01

    The diversity and beneficial characteristics of endophytic microorganisms have been studied in several host plants. However, information regarding naturally occurring seed-associated endophytes and vertical transmission among different life-history stages of hosts is limited. Endophytic bacteria were isolated from seeds and seedlings of 10 Eucalyptus species and two hybrids. The results showed that endophytic bacteria, such as Bacillus, Enterococcus, Paenibacillus and Methylobacterium, are vertically transferred from seeds to seedlings. In addition, the endophytic bacterium Pantoea agglomerans was tagged with the gfp gene, inoculated into seeds and further reisolated from seedlings. These results suggested a novel approach to change the profile of the plants, where the bacterium is a delivery vehicle for desired traits. This is the first report of an endophytic bacterial community residing in Eucalyptus seeds and the transmission of these bacteria from seeds to seedlings. The bacterial species reported in this work have been described as providing benefits to host plants. Therefore, we suggest that endophytic bacteria can be transmitted vertically from seeds to seedlings, assuring the support of the bacterial community in the host plant.

  12. Bacteriophages LIMElight and LIMEzero of Pantoea agglomerans, Belonging to the “phiKMV-Like Viruses” ▿ †

    PubMed Central

    Adriaenssens, Evelien M.; Ceyssens, Pieter-Jan; Dunon, Vincent; Ackermann, Hans-Wolfgang; Van Vaerenbergh, Johan; Maes, Martine; De Proft, Maurice; Lavigne, Rob

    2011-01-01

    Pantoea agglomerans is a common soil bacterium used in the biocontrol of fungi and bacteria but is also an opportunistic human pathogen. It has been described extensively in this context, but knowledge of bacteriophages infecting this species is limited. Bacteriophages LIMEzero and LIMElight of P. agglomerans are lytic phages, isolated from soil samples, belonging to the Podoviridae and are the first Pantoea phages of this family to be described. The double-stranded DNA (dsDNA) genomes (43,032 bp and 44,546 bp, respectively) encode 57 and 55 open reading frames (ORFs). Based on the presence of an RNA polymerase in their genomes and their overall genome architecture, these phages should be classified in the subfamily of the Autographivirinae, within the genus of the “phiKMV-like viruses.” Phylogenetic analysis of all the sequenced members of the Autographivirinae supports the classification of phages LIMElight and LIMEzero as members of the “phiKMV-like viruses” and corroborates the subdivision into the different genera. These data expand the knowledge of Pantoea phages and illustrate the wide host diversity of phages within the “phiKMV-like viruses.” PMID:21421778

  13. Pantoea vagans sp. nov., Pantoea eucalypti sp. nov., Pantoea deleyi sp. nov. and Pantoea anthophila sp. nov.

    PubMed

    Brady, Carrie L; Venter, Stephanus N; Cleenwerck, Ilse; Engelbeen, Katrien; Vancanneyt, Marc; Swings, Jean; Coutinho, Teresa A

    2009-09-01

    Bacteria isolated from eucalyptus leaves and shoots showing symptoms of blight and die-back collected in Uganda, Uruguay and Argentina and from maize displaying brown stalk rot symptoms in South Africa were tentatively placed in the genus Pantoea on the basis of phenotypic and biochemical tests. These isolates, together with two strains (LMG 2558 and LMG 2560) previously assigned to Pantoea agglomerans based on protein electrophoregrams but later excluded from this species, were further investigated using molecular techniques. 16S rRNA gene sequencing and multilocus sequence analyses (MLSA) revealed that the strains were phylogenetically closely related to Pantoea agglomerans, Pantoea stewartii and Pantoea ananatis. MLSA and amplified fragment length polymorphism analysis placed the strains into four separate clusters, not containing any of the type strains of species of the genus Pantoea. DNA-DNA hybridization confirmed the classification of the isolates into four novel species, for which the names Pantoea vagans sp. nov. (type strain R-21566T=LMG 24199T=BCC 105T=BD 765T), Pantoea eucalypti sp. nov. (type strain R-25678T=LMG 24197T=BCC 076T=BD 769T), Pantoea deleyi sp. nov. (type strain R-31523T=LMG 24200T=BCC 109T=BD 767T) and Pantoea anthophila sp. nov. (type strain LMG 2558T=BD 871T=NCPPB 1682T) are proposed.

  14. Preventive and curative activity of combined treatments of sodium carbonates and Pantoea agglomerans CPA-2 to control postharvest green mold of citrus fruit

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Preventive and curative activity of 2 min dips in 3% sodium carbonate (SC) or sodium bicarbonate (SBC) aqueous solutions heated to 40ºC, alone of followed by the application of 2 x 108 CFU/ml of the biocontrol agent Pantoea agglomerans CPA-2 (BA), in the control of postharvest green mold, caused by ...

  15. Effect of biocontrol agents Candida sake and Pantoea agglomerans on Penicillium expansum growth and patulin accumulation in apples.

    PubMed

    Morales, Hector; Sanchis, Vicente; Usall, Josep; Ramos, Antonio J; Marín, Sonia

    2008-02-29

    Penicillium expansum is the major responsible of fruit pome decaying in cold storage. Apples spoiled by P. expansum are expected to contain patulin, a mycotoxin which is proven to affect human health. The use of chemicals is the most common procedure to prevent rots in postharvest but legislation is becoming more and more restrictive. The use of biocontrol agents (BCA) as an alternative tool is currently being proposed. The aim of this study was to evaluate the effect of two BCA (Candida sake CPA-2 and Pantoea agglomerans CPA-1) on P. expansum growth and patulin accumulation in cold storage and further deck (ambient) storage. Wounded apples were inoculated with a cell suspension of either C. sake or P. agglomerans and with a P. expansum conidial suspension. Apples were cold stored at 1 degrees C until lesion diameter reached 2 or 4 cm. Half the apples of each treatment were further stored at 20 degrees C for three days before patulin analyses. Both BCA tested controlled blue rot and patulin accumulation during cold storage. The control of P. expansum growth was enhanced in C. sake treated apples. On the other side, control of patulin accumulation in P. agglomerans treated apples seemed to be more efficient. BCA treatment could not control blue rot and patulin accumulation during further storage at room temperature and in some cases, an increase in P. expansum aggressiveness was observed.

  16. Pantoea agglomerans: a mysterious bacterium of evil and good. Part II--Deleterious effects: Dust-borne endotoxins and allergens--focus on grain dust, other agricultural dusts and wood dust.

    PubMed

    Dutkiewicz, Jacek; Mackiewicz, Barbara; Lemieszek, Marta Kinga; Golec, Marcin; Skórska, Czesława; Góra-Florek, Anna; Milanowski, Janusz

    2016-01-01

    Pantoea agglomerans, a Gram-negative bacterium developing in a variety of plants as epiphyte or endophyte is particularly common in grain and grain dust, and has been identified by an interdisciplinary group from Lublin, eastern Poland, as a causative agent of work-related diseases associated with exposure to grain dust and other agricultural dusts. The concentration of P. agglomerans in grain as well as in the settled grain and flour dust was found to be high, ranging from 10(4)-10(8) CFU/g, while in the air polluted with grain or flour dust it ranged from 10(3)-10(5) CFU/m(3) and formed 73.2-96% of the total airborne Gram-negative bacteria. The concentration of P. agglomerans was also relatively high in the air of the facilities processing herbs and other plant materials, while it was lower in animal farms and in wood processing facilities. Pantoea agglomerans produces a biologically-potent endotoxin (cell wall lipopolysaccharide, LPS). The significant part of this endotoxin occurs in dusts in the form of virus-sized globular nanoparticles measuring 10-50 nm that could be described as the 'endotoxin super-macromolecules'. A highly significant relationship was found (R=0.804, P=0.000927) between the concentration of the viable P. agglomerans in the air of various agricultural and wood industry settings and the concentration of bacterial endotoxin in the air, as assessed by the Limulus test. Although this result may be interfered by the presence of endotoxin produced by other Gram-negative species, it unequivocally suggests the primary role of the P. agglomerans endotoxin as an adverse agent in the agricultural working environment, causing toxic pneumonitis (ODTS). Numerous experiments by the inhalation exposure of animals to various extracts of P. agglomerans strains isolated from grain dust, including endotoxin isolated with trichloroacetic acid (LPS-TCA), endotoxin nanoparticles isolated in sucrose gradient (VECN), and mixture of proteins and endotoxin obtained

  17. Global regulatory networks control the hrp regulon of the gall-forming bacterium Pantoea agglomerans pv. gypsophilae.

    PubMed

    Panijel, Mary; Chalupowicz, Laura; Sessa, Guido; Manulis-Sasson, Shulamit; Barash, Isaac

    2013-09-01

    Gall formation by Pantoea agglomerans pv. gypsophilae is dependent on the hypersensitive response and pathogenicity (hrp) system. Previous studies demonstrated that PagR and PagI, regulators of the quorum-sensing system, induce expression of the hrp regulatory cascade (i.e., hrpXY, hrpS, and hrpL) that activates the HrpL regulon. Here, we isolated the genes of the Gac/Rsm global regulatory pathway (i.e., gacS, gacA, rsmB, and csrD) and of the post-transcriptional regulator rsmA. Our results demonstrate that PagR and PagI also upregulate expression of the Gac/Rsm pathway. PagR acts as a transcriptional activator of each of the hrp regulatory genes and gacA in a N-butanoyl-L-homoserine lactone-dependent manner as shown by gel shift experiments. Mutants of the Gac/Rsm genes or overexpression of rsmA significantly reduced Pantoea agglomerans virulence and colonization of gypsophila. Overexpression of rsmB sRNA abolished gall formation, colonization, and hypersensitive reaction on nonhost plants and prevented transcription of the hrp regulatory cascade, indicating a lack of functional type III secretion system. Expression of rsmB sRNA in the background of the csrD null mutant suggests that CsrD may act as a safeguard for preventing excessive production of rsmB sRNA. Results presented indicate that the hrp regulatory cascade is controlled directly by PagR and indirectly by RsmA, whereas deficiency in RsmA activity is epistatic to PagR induction.

  18. Influence of diluent and sample processing methods on the recovery of the biocontrol agent Pantoea agglomerans CPA-2 from different fruit surfaces.

    PubMed

    Torres, R; Viñas, I; Usall, J; Remón, D; Teixidó, N

    2012-08-01

    Determining the populations of biocontrol agents applied as a postharvest treatment on fruit surfaces is fundamental to the assessment of the microorganisms' ability to colonise and persist on fruit. To obtain maximum recovery, we must develop a methodology that involves both diluent and processing methods and that does not affect the viability of the microorganisms. The effect of diluent composition was evaluated using three diluents: phosphate buffer, peptone saline and buffered peptone saline. An additional study was performed to compare three processing methods (shaking plus sonication, stomaching and shaking plus centrifugation) on the recovery efficiency of Pantoea agglomerans strain CPA-2 from apples, oranges, nectarines and peaches treated with this biocontrol agent. Overall, slight differences occurred among diluents, although the phosphate buffer maintained the most ideal pH for CPA-2 growth (between 5.2 and 6.2). Stomaching, using the phosphate buffer as diluent, was the best procedure for recovering and enumerating the biocontrol agent; this fact suggested that no lethal effects from naturally occurring antimicrobial compounds present on the fruit skins and/or produced when the tissues were disrupted affected the recovery of the CPA-2 cells, regardless of fruit type. The growth pattern of CPA-2 on fruits maintained at 20°C and under cold conditions was similar to that obtained in previous studies, which confirms the excellent adaptation of this strain to conditions commonly used for fruit storage.

  19. Transmission of Pantoea ananatis and P. agglomerans, causal agents of center rot of onion (Allium cepa), by onion thrips (Thrips tabaci) through feces.

    PubMed

    Dutta, B; Barman, A K; Srinivasan, R; Avci, U; Ullman, D E; Langston, D B; Gitaitis, R D

    2014-08-01

    Frankliniella fusca, the tobacco thrips, has been shown to acquire and transmit Pantoea ananatis, one of the causal agents of the center rot of onion. Although Thrips tabaci, the onion thrips, is a common pest of onions, its role as a vector of P. ananatis has been unknown. The bacterium, P. agglomerans, is also associated with the center rot of onion, but its transmission by thrips has not been previously investigated. In this study, we investigated the relationship of T. tabaci with P. ananatis and P. agglomerans. Surface-sterilized T. tabaci were provided with various acquisition access periods (AAP) on onion leaves inoculated with either P. ananatis or P. agglomerans. A positive exponential relationship was observed between thrips AAP duration and P. ananatis (R² = 0.967; P = 0.023) or P. agglomerans acquisition (R² = 0.958; P = 0.017). Transmission experiments conducted with T. tabaci adults indicated that 70% of the seedlings developed center rot symptoms 15 days after inoculation. Immunofluorescence microscopy with antibodies specific to P. ananatis revealed that the bacterium was localized only in the gut of T. tabaci adults. Mechanical inoculation of onion seedlings with fecal rinsates alone produced center rot but not with salivary secretions. Together these results suggested that T. tabaci could efficiently transmit P. ananatis and P. agglomerans.

  20. Characterization of the Biosynthetic Operon for the Antibacterial Peptide Herbicolin in Pantoea vagans Biocontrol Strain C9-1 and Incidence in Pantoea Species

    PubMed Central

    Kamber, Tim; Lansdell, Theresa A.; Stockwell, Virginia O.; Ishimaru, Carol A.; Smits, Theo H. M.

    2012-01-01

    Pantoea vagans C9-1 is a biocontrol strain that produces at least two antibiotics inhibiting the growth of Erwinia amylovora, the causal agent of fire blight disease of pear and apple. One antibiotic, herbicolin I, was purified from culture filtrates of P. vagans C9-1 and determined to be 2-amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine, also known as Nß-epoxysuccinamoyl-DAP-valine. A plasposon library was screened for mutants that had lost the ability to produce herbicolin I. It was shown that mutants had reduced biocontrol efficacy in immature pear assays. The biosynthetic gene cluster in P. vagans C9-1 was identified by sequencing the flanking regions of the plasposon insertion sites. The herbicolin I biosynthetic gene cluster consists of 10 coding sequences (CDS) and is located on the 166-kb plasmid pPag2. Sequence comparisons identified orthologous gene clusters in Pantoea agglomerans CU0119 and Serratia proteamaculans 568. A low incidence of detection of the biosynthetic cluster in a collection of 45 Pantoea spp. from biocontrol, environmental, and clinical origins showed that this is a rare trait among the tested strains. PMID:22504810

  1. DNA-based methodologies for the quantification of live and dead cells in formulated biocontrol products based on Pantoea agglomerans CPA-2.

    PubMed

    Soto-Muñoz, Lourdes; Torres, Rosario; Usall, Josep; Viñas, Inmaculada; Solsona, Cristina; Teixidó, Neus

    2015-10-01

    Pantoea agglomerans strain CPA-2 is an effective biocontrol agent (BCA) against the major postharvest pathogens present on pome and citrus fruits. Dehydration, such as freeze-drying, spray-drying and fluidized bed drying is one of the best ways to formulate BCAs. In this work, the survival of CPA-2 cells after formulation was determined by dilution plating and molecular methods as qPCR alone and combined with a sample pretreatment with a propidium monoazide dye (PMA-qPCR) and they were used to calculate treatment concentrations in efficacy trials on postharvest oranges. Furthermore, no significant differences in CPA-2 survival were observed as determined by dilution plating and PMA-qPCR after both the freeze drying and fluidized bed drying processes; however, an interesting significant difference was observed in the spray dried product comparing all quantitative methods. A difference of 0.48 and 2.17 log10 CFU or cells g/dw was observed among PMA-qPCR with qPCR and dilution plating, respectively. According to our study, dilution plating was shown to be an unreliable tool for monitoring the survival of CPA-2 after spray drying. In contrast, the combination of PMA and qPCR enabled a quick and unequivocal methodology to enumerate viable and VBNC CPA-2 cells under stress-dried conditions. Efficacy trials showed that, after 3 days, spray drying formulation rehydrated with 10% non-fat skimmed milk (NFSM) was as effective as fresh cells to control Penicillium digitatum in oranges.

  2. Regulatory interactions between quorum-sensing, auxin, cytokinin, and the Hrp regulon in relation to gall formation and epiphytic fitness of Pantoea agglomerans pv. gypsophilae.

    PubMed

    Chalupowicz, Laura; Barash, Isaac; Panijel, Mary; Sessa, Guido; Manulis-Sasson, Shulamit

    2009-07-01

    Gall formation by Pantoea agglomerans pv. gypsophilae is controlled by hrp/hrc genes, phytohormones, and the quorum-sensing (QS) regulatory system. The interactions between these three components were investigated. Disruption of the QS genes pagI and pagR and deletion of both substantially reduced the transcription levels of the hrp regulatory genes hrpXY, hrpS, and hrpL, as determined by quantitative reverse-transcriptase polymerase chain reaction. Expression of hrpL in planta was inhibited by addition of 20 microM or higher concentrations of the QS signal C(4)-HSL. The pagR and hrpL mutants caused an equivalent reduction of 1.3 orders in bacterial multiplication on bean leaves, suggesting possible mediation of the QS effect on epiphytic fitness of P. agglomerans pv. gypsophilae by the hrp regulatory system. indole-3-acetic acid (IAA) and cytokinin significantly affected the expression of the QS and hrp regulatory genes. Transcription of pagI, pagR, hrpL, and hrpS in planta was substantially reduced in iaaH mutant (disrupted in IAA biosynthesis via the indole-3-acetamide pathway) and etz mutant (disrupted in cytokinin biosynthesis). In contrast, the ipdC mutant (disrupted in IAA biosynthesis via the indole-3-pyruvate pathway) substantially increased expression of pagI, pagR, hrpL, and hrpS. Results presented suggest the involvement of IAA and cytokinins in regulation of the QS system and hrp regulatory genes.

  3. Epidemiology and molecular characterization of extended-spectrum beta-lactamase-producing Enterobacter spp., Pantoea agglomerans, and Serratia marcescens isolates from a Bulgarian hospital.

    PubMed

    Markovska, Rumyana Donkova; Stoeva, Temenuga Jekova; Bojkova, Kalina Dineva; Mitov, Ivan Gergov

    2014-04-01

    Forty-two extended-spectrum beta-lactamase (ESBL)-producing isolates of Enterobacter aerogenes, Enterobacter cloacae, Pantoea agglomerans, and Serratia marcescens, collected consecutively during the period January-November 2011 from the University Hospital in Varna, Bulgaria, were studied to characterize their ESBLs by isoelectric focusing, group-specific PCR, and sequencing. The epidemiological relationship was evaluated by random amplified polymorphic DNA analysis (RAPD). Transferability of ESBL genes was determined by conjugation experiments. Plasmid analysis was done by replicon typing and PstI fingerprinting. The overall rate of ESBL production was 20%. The most widespread enzyme was CTX-M-3, found in 64%. It was dominant in E. aerogenes (100%) and S. marcescens (83%). SHV-12, CTX-M-3, and CTX-M-15 were found among E. cloacae isolates in 50%, 35%, and 45%, respectively. Three main CTX-M-3-producing epidemic clones of E. aerogenes and S. marcescens have been detected. Among E. cloacae isolates, six different RAPD profiles were discerned. The plasmids harboring blaCTX-M-3 belonged to IncL/M type and demonstrated similar PstI fingerprinting profiles. IncFII plasmids were detected in two CTX-M-15-producing E. cloacae isolates. Our results demonstrate wide intrahospital dissemination of clonal E. aerogenes and S. marcescens isolates, carrying IncL/M conjugative plasmids.

  4. A Lipopolysaccharide from Pantoea Agglomerans Is a Promising Adjuvant for Sublingual Vaccines to Induce Systemic and Mucosal Immune Responses in Mice via TLR4 Pathway

    PubMed Central

    Kiyotoh, Eiji; Okazaki, Arimichi; Gomi, Yasuyuki; Tanimoto, Takeshi; Takeuchi, Osamu; Akira, Shizuo; Hori, Mitsuhiko

    2015-01-01

    A lipopolysaccharide from Pantoea agglomerans (LPSpa) has been applied to various fields for human use as a Toll-like receptor 4 ligand and its safety has been confirmed. Here, we showed for the first time the application of LPSpa as an effective mucosal adjuvant for activating vaccine-induced antigen specific immune responses. Mice sublingually immunized with influenza vaccine (HA split vaccine) with LPSpa induced both HA-specific IgG (systemic) and IgA (mucosal) antibody responses, which led to a significant increase in survival rate against lethal influenza virus challenge compared with subcutaneous vaccination. After sublingual administration of ovalbumin with LPSpa, ovalbumin-specific mucosal IgA responses were induced at both mucosal surfaces close to the immunized site and at remote mucosal surfaces. Sublingual administration of LPSpa evoked local antigen-uptake by dendritic cells in cervical lymph nodes. LPSpa induced cytokine production and the maturation and proliferation of innate immune cells via Toll-like receptor 4 in dendritic cells. Collectively, these results suggest that LPSpa can be used as an effective mucosal adjuvant to stimulate and activate local innate immune cells to improve and enhance mucosal vaccine potency against various pathogens. PMID:25978818

  5. Pantoea applied genomics to understand and improve biocontrol activity against fire blight

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pantoea agglomerans and P. vagans (ex. Erwinia herbicola) are common epiphytes of pome fruit flowers and three strains (E325, P10c, C9-1) have been commercially developed as effective biocontrol products for managing fire blight (Erwinia amylovora). Antibiotics as a standard, reliable chemical optio...

  6. Investigation of Viability of Pantoea agglomerans (Formerly Erwinia herbicola) After Aerosolization From Media Containing Enriching and Coating Chemicals

    DTIC Science & Technology

    2008-02-01

    issue in aerosol testing of vegetative cells, which might be found in the environment. The viability of this bacterial strain has usually been poor during...the foliage of pear trees, when the powder was sprayed to protect the orchard from fire blight . Costa et al. (2002) tested the effects of spray... bacterial growth conditions and after-growth treatments used in the experiments described in this section were prepared as follows: * Eh in TSB: An Eh

  7. Emended description of the genus Pantoea, description of four species from human clinical samples, Pantoea septica sp. nov., Pantoea eucrina sp. nov., Pantoea brenneri sp. nov. and Pantoea conspicua sp. nov., and transfer of Pectobacterium cypripedii (Hori 1911) Brenner et al. 1973 emend. Hauben et al. 1998 to the genus as Pantoea cypripedii comb. nov.

    PubMed

    Brady, Carrie L; Cleenwerck, Ilse; Venter, Stephanus N; Engelbeen, Katrien; De Vos, Paul; Coutinho, Teresa A

    2010-10-01

    Bacterial strains belonging to DNA hybridization groups (HG) II, IV and V, in the Erwinia herbicola-Enterobacter agglomerans complex, of Brenner et al. [Int J Syst Bacteriol 34 (1984), 45-55] were suggested previously to belong to the genus Pantoea, but have never been formally described and classified. Additionally, it has been shown in several studies that Pectobacterium cypripedii is more closely related to species of Pantoea than to those of Pectobacterium. In this study, the phylogenetic positions of Brenner's DNA HG II, IV and V and Pectobacterium cypripedii were re-examined by both 16S rRNA gene sequencing and multilocus sequence analyses (MLSA) based on the gyrB, rpoB, atpD and infB genes. The analyses revealed that DNA HG II, IV and V and Pectobacterium cypripedii form five separate branches within the genus Pantoea (strains from HG V were split into two branches). DNA-DNA hybridization data further confirmed that DNA HG II, IV and V constitute four separate species. Pectobacterium cypripedii was shown to be a close phylogenetic relative of Pantoea dispersa and DNA HG IV by both 16S rRNA gene sequence and MLSA analyses. Biochemical analyses performed on strains from DNA HG II, IV and V and Pectobacterium cypripedii confirmed their taxonomic position within the genus Pantoea and revealed phenotypic characteristics that allow the differentiation of these species from each other and from their closest phylogenetic neighbours. It is proposed to emend the description of the genus Pantoea and to describe Pantoea septica sp. nov. for DNA HG II (type strain LMG 5345(T) =BD 874(T) =CDC 3123-70(T)), Pantoea eucrina sp. nov. for DNA HG IV (type strain LMG 2781(T) =BD 872(T) =CDC 1741-71(T) =LMG 5346(T)), Pantoea brenneri sp. nov. for strains of DNA HG V excluding LMG 24534 (type strain LMG 5343(T) =BD 873(T) =CDC 3482-71(T)) and Pantoea conspicua sp. nov. for the remaining strain of DNA HG V (type strain LMG 24534(T) =BD 805(T) =CDC 3527-71(T)) and to transfer

  8. Degradation of acephate by Enterobacter asburiae, Bacillus cereus and Pantoea agglomerans isolated from diamondback moth Plutella xylostella (L), a pest of cruciferous crops.

    PubMed

    Ramya, Shanivarsanthe Leelesh; Venkatesan, Thiruvengadam; Murthy, Kottilingam Srinivasa; Jalali, Sushil Kumar; Varghese, Abraham

    2016-07-01

    Acephate-degrading bacterial isolates were isolated from the larval gut of diamondback moth Plutella xylostella, a notorious pest of cruciferous crops worldwide that has developed resistance to insecticides. Partial 16S rRNA gene sequencing identified the isolates as Bacillus cereus (PX-B.C.Or), Enterobacter asburiae (PXE), and Pantoae agglomerans (PX-Pt.ag.Jor). All isolates grew on minimal media (MM) in the presence of acephate at 100 and 200 ppm, with maximum growth at 200 ppm. LC-MS analyses of spent medium showed that E. asburiae degraded acephate to methamidophos and O, O-dimethyl phosporamidate and B. cereus O,S-dimethyl to phosphorothioate but P. agglomerans to an unnamed compound. All three isolates used acephate as a source of carbon and energy for growth; however, P. agglomerans used it also as source of sulphur. Strong evidence revealed that the bacterial communities present in the gut of diamondback moth might aid in acephate degradation and play a role in the development of insecticide resistance.

  9. Influence of native plasmids to fitness of Pantoea vagans strain C9-1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pantoea vagans strain C9-1 is a biological control agent for fire blight caused by Erwinia amylovora. We cured C9-1 of two of its three plasmids: pPag2, pPag3, and both pPag2 and pPag3, tested phenotypes of the derivatives, and evaluated blossom colonization in the field. pPag2 (166 kb) encodes for ...

  10. Phylogeny and identification of Pantoea species associated with plants, humans and the natural environment based on multilocus sequence analysis (MLSA).

    PubMed

    Brady, Carrie; Cleenwerck, Ilse; Venter, Stephanus; Vancanneyt, Marc; Swings, Jean; Coutinho, Teresa

    2008-12-01

    Species belonging to the genus of Pantoea are commonly isolated from plants, humans and the natural environment. The species of the genus are phenotypically closely related, making rapid identification of Pantoea strains to the species level difficult. Multilocus sequence analysis (MLSA) was evaluated as a means for rapid classification and identification of Pantoea strains. Four housekeeping genes, gyrB, rpoB, atpD and infB, were sequenced for strains assigned to the genus. Included in the study were (1) reference strains from the seven currently recognized species of Pantoea, (2) strains belonging to Brenner DNA groups II, IV and V, previously isolated from clinical samples and difficult to identify because of high phenotypic similarity to P. agglomerans or P. ananatis and (3) isolates from diseased Eucalyptus, maize and onion, assigned to the genus on the basis of phenotypic tests. Phylogenetic trees were constructed from the sequences of the four housekeeping genes. The "core"Pantoea species formed a cluster separate from the "Japanese" species which formed a tight cluster that included the genus Tatumella when the tree was based on concatenated sequences of the four genes. The MLSA data further suggested the existence of ten potential novel species, phylogenetically related to the currently recognized Pantoea species and the possible inclusion of Pectobacterium cypripedii in the genus Pantoea. When compared with DNA-DNA hybridization data, a good congruence was observed between both methods, with gyrB sequence data being the most consistent. In conclusion, MLSA of partial nucleotide sequences of the genes gyrB, rpoB, atpD and infB can be used for classification, identification and phylogenetic analyses of Pantoea strains.

  11. Pathways for degrading TNT by Thu-Z: a Pantoea sp. strain.

    PubMed

    Zou, Liangdong; Lu, Diannan; Liu, Zheng

    2012-12-01

    2,4,6-Trinitrotoluene (TNT), an extensively used and versatile explosive, is harmful in soil and water. In the present study, four bacterial strains capable of degrading TNT have been isolated from contaminated sites and named as Thu-A, Thu-B, Thu-C, and Thu-Z. Thu-Z, which gave the highest degradation efficiency compared to the others, was assigned to the genus Pantoea according to its 16S rRNA gene. Similarities in both biochemical properties and morphology suggested that Thu-Z was a Pantoea sp. strain. Thu-Z was proved to be capable of using TNT as a sole nitrogen source by cleaving NO(2) from the nitroaromatic ring by direct aromatic ring reduction. Under nitrogen-limited conditions, 96.6 % N of TNT was consumed by Thu-Z for growth, which was determined in terms of NaNO(2). Trace nitro reduction metabolites such as 2,4-diamino-6-nitrotoluene (24Dam) and 2,6-diamino-4-nitrotoluene (26Dam) were identified in the presence of (NH(4))(2)SO(4). On the other hand, 4,4',6,6'-tetranitro-2,2'-azoxytoluene (22Azo) and 2,2',6,6'-tetranitro-4,4'-azoxytoluene (44Azo) were detected in the absence of (NH(4))(2)SO(4). These indicated the existence of a dual pathway for Thu-Z, while the direct aromatic ring reduction was predominant. Addition of a nitrogen source ((NH(4))(2)SO(4)) after inoculation stimulated the growth of Thu-Z and accelerated TNT degradation.

  12. Comparative genomics of type VI secretion systems in strains of Pantoea ananatis from different environments

    PubMed Central

    2014-01-01

    Background The Type VI secretion system (T6SS) has been identified in several different bacteria, including the plant pathogenPantoea ananatis. Previous in silico analyses described three different T6SS loci present in the pathogenic strain of P. ananatis LMG 20103. This initial investigation has been extended to include an additional seven sequenced strains of P. ananatis together with 39 strains from different ecological niches. Comparative and phylogenetic analyses were used to investigate the distribution, evolution, intra-strain variability and operon structure of the T6SS in the sequenced strains. Results Three different T6SS loci were identified in P. ananatis strain LMG 20103 and designated PA T6SS 1-3. PA T6SS-1 was present in all sequenced strains of P. ananatis and in all 39 additional strains examined in this study. In addition, PA T6SS-1 included all 13 core T6SS genes required for synthesis of a functional T6SS. The plasmid-borne PA T6SS-2 also included all 13 core T6SS genes but was restricted to only 33% (15/46) of the strains examined. In addition, PA T6SS-2 was restricted to strains of P. ananatis isolated from symptomatic plant material. This finding raises the possibility of an association between PA T6SS-2 and either pathogenicity or host specificity. The third cluster PA T6SS-3 was present in all strains analyzed in this study but lacked 11 of the 13 core T6SS genes suggesting it may not encoded a functional T6SS. Inter-strain variability was also associated with hcp and vgrG islands, which are associated with the T6SS and encode a variable number of proteins usually of unknown function. These proteins may play a role in the fitness of different strains in a variety of ecological niches or as candidate T6SS effectors. Phylogenetic analysis indicated that PA T6SS-1 and PA T6SS-2 are evolutionarily distinct. Conclusion Our analysis indicates that the three T6SSs of P. ananatis appear to have been independently acquired and may play different

  13. High-quality draft genome sequence of a new phytase-producing microorganism Pantoea sp. 3.5.1.

    PubMed

    Suleimanova, Aliya D; Toymentseva, Anna A; Boulygina, Eugenia A; Kazakov, Sergey V; Mardanova, Ayslu M; Balaban, Nelly P; Sharipova, Margarita R

    2015-01-01

    Strain 3.5.1 was isolated from soils of the Republic of Tatarstan, Russia, on the basis of presence of a high phytate-degrading activity. Strains with such activities attract special interest because of its potential use as feed additives and natural manures. Strain 3.5.1 harbors a 99 % 16S rRNA nucleotide sequence similarity to different Pantoea species (P. vagans, P. ananatis, P. agglomerans, P. anthophila and Pantoea sp.) and exhibits unique biochemical properties that do not allow strain identification up to species. Moreover, the strain 3.5.1 shows a low ANI and MALDI-TOF Mass Spectrometry scores. Thus, it is likely that the strain 3.5.1 represents a new Pantoea species. Here, we present the genome sequence of Pantoea sp. strain 3.5.1. The 4,964,649 bp draft genome consists of 23 contigs with 4,556 protein-coding and 143 RNA genes. Genome sequencing and annotation revealed two phytase genes and putative regulatory genes controlling its activity.

  14. Genome Sequence of Pantoea annatis strain CFH 7-1, which is associated with a vector-borne cotton fruit disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pantoea ananatis is a bacterium with versatile niches that vary from pathogenic to beneficial. We present the genome of strain CFH 7-1, which was recovered from a diseased greenhouse cotton boll previously caged with a field-collected cotton fleahopper (Pseudatomoscelis seriatus). These data will ...

  15. Pantoea rodasii sp. nov., Pantoea rwandensis sp. nov. and Pantoea wallisii sp. nov., isolated from Eucalyptus.

    PubMed

    Brady, Carrie L; Cleenwerck, Ilse; van der Westhuizen, Lorinda; Venter, Stephanus N; Coutinho, Teresa A; De Vos, Paul

    2012-07-01

    Several Gram-negative-staining, facultatively anaerobic bacterial isolates were obtained from Eucalyptus seedlings showing symptoms of bacterial blight and dieback in Colombia, Rwanda and South Africa. Partial 16S rRNA gene sequencing, together with partial gyrB sequencing, placed the isolates in the genus Pantoea and indicated that they constituted three novel species. Multilocus sequence analysis (MLSA) based on partial sequences of gyrB, rpoB, infB and atpD revealed Pantoea dispersa, Pantoea eucrina and Pantoea cypripedii as their closest phylogenetic relatives. DNA-DNA hybridization studies confirmed the classification of the new isolates as three novel species and phenotypic tests allowed them to be differentiated from their closest phylogenetic neighbours. The names Pantoea rodasii sp. nov. [type strain LMG 26273(T)=BD 943(T) (deposited with the Plant Pathogenic and Plant Protecting Bacteria Collection, South Africa)=BCC 581(T) (deposited with the Bacterial Culture Collection, Forestry and Agricultural Institute, South Africa)], Pantoea rwandensis sp. nov. (type strain LMG 26275(T)=BD 944(T)=BCC 571(T)) and Pantoea wallisii sp. nov. (type strain LMG 26277(T)=BD 946(T)=BCC 682(T)) are proposed.

  16. Novel Glucose-1-Phosphatase with High Phytase Activity and Unusual Metal Ion Activation from Soil Bacterium Pantoea sp. Strain 3.5.1.

    PubMed

    Suleimanova, Aliya D; Beinhauer, Astrid; Valeeva, Liia R; Chastukhina, Inna B; Balaban, Nelly P; Shakirov, Eugene V; Greiner, Ralf; Sharipova, Margarita R

    2015-10-01

    Phosphorus is an important macronutrient, but its availability in soil is limited. Many soil microorganisms improve the bioavailability of phosphate by releasing it from various organic compounds, including phytate. To investigate the diversity of phytate-hydrolyzing bacteria in soil, we sampled soils of various ecological habitats, including forest, private homesteads, large agricultural complexes, and urban landscapes. Bacterial isolate Pantoea sp. strain 3.5.1 with the highest level of phytase activity was isolated from forest soil and investigated further. The Pantoea sp. 3.5.1 agpP gene encoding a novel glucose-1-phosphatase with high phytase activity was identified, and the corresponding protein was purified to apparent homogeneity, sequenced by mass spectroscopy, and biochemically characterized. The AgpP enzyme exhibits maximum activity and stability at pH 4.5 and at 37°C. The enzyme belongs to a group of histidine acid phosphatases and has the lowest Km values toward phytate, glucose-6-phosphate, and glucose-1-phosphate. Unexpectedly, stimulation of enzymatic activity by several divalent metal ions was observed for the AgpP enzyme. High-performance liquid chromatography (HPLC) and high-performance ion chromatography (HPIC) analyses of phytate hydrolysis products identify dl-myo-inositol 1,2,4,5,6-pentakisphosphate as the final product of the reaction, indicating that the Pantoea sp. AgpP glucose-1-phosphatase can be classified as a 3-phytase. The identification of the Pantoea sp. AgpP phytase and its unusual regulation by metal ions highlight the remarkable diversity of phosphorus metabolism regulation in soil bacteria. Furthermore, our data indicate that natural forest soils harbor rich reservoirs of novel phytate-hydrolyzing enzymes with unique biochemical features.

  17. Novel Glucose-1-Phosphatase with High Phytase Activity and Unusual Metal Ion Activation from Soil Bacterium Pantoea sp. Strain 3.5.1

    PubMed Central

    Suleimanova, Aliya D.; Beinhauer, Astrid; Valeeva, Liia R.; Chastukhina, Inna B.; Balaban, Nelly P.; Greiner, Ralf

    2015-01-01

    Phosphorus is an important macronutrient, but its availability in soil is limited. Many soil microorganisms improve the bioavailability of phosphate by releasing it from various organic compounds, including phytate. To investigate the diversity of phytate-hydrolyzing bacteria in soil, we sampled soils of various ecological habitats, including forest, private homesteads, large agricultural complexes, and urban landscapes. Bacterial isolate Pantoea sp. strain 3.5.1 with the highest level of phytase activity was isolated from forest soil and investigated further. The Pantoea sp. 3.5.1 agpP gene encoding a novel glucose-1-phosphatase with high phytase activity was identified, and the corresponding protein was purified to apparent homogeneity, sequenced by mass spectroscopy, and biochemically characterized. The AgpP enzyme exhibits maximum activity and stability at pH 4.5 and at 37°C. The enzyme belongs to a group of histidine acid phosphatases and has the lowest Km values toward phytate, glucose-6-phosphate, and glucose-1-phosphate. Unexpectedly, stimulation of enzymatic activity by several divalent metal ions was observed for the AgpP enzyme. High-performance liquid chromatography (HPLC) and high-performance ion chromatography (HPIC) analyses of phytate hydrolysis products identify dl-myo-inositol 1,2,4,5,6-pentakisphosphate as the final product of the reaction, indicating that the Pantoea sp. AgpP glucose-1-phosphatase can be classified as a 3-phytase. The identification of the Pantoea sp. AgpP phytase and its unusual regulation by metal ions highlight the remarkable diversity of phosphorus metabolism regulation in soil bacteria. Furthermore, our data indicate that natural forest soils harbor rich reservoirs of novel phytate-hydrolyzing enzymes with unique biochemical features. PMID:26209662

  18. Effects of postharvest onion curing parameters on bulb rot caused by Pantoea agglomerans, Pantoea ananatis, and Pantoea allii in storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop loss of onion bulbs during storage carries an exceptionally high economic impact since a large portion of the production expenses have been expended before storage occurs. Because of this, it is important to define practices that can reduce onion bulb losses caused by storage rots. This study...

  19. The isolation and identification of Pantoea dispersa strain JFS as a non-pathogenic surrogate for Salmonella Typhimurium phage type 42 in flour.

    PubMed

    Fudge, James; Dunn, Michael; Pike, Oscar; Robison, Richard; Steele, Frost

    2016-02-16

    Salmonella is a common pathogen which has been the cause of foodborne illness outbreaks implicating a variety of commodities, including low-moisture foods such as flour. Salmonella costs more than any other pathogen in the United States in terms of health care expenses and time of lost work. Heat treatment can be used to reduce Salmonella and other pathogens in flour to safe levels. However, in low-moisture foods, process times must be increased to achieve adequate lethality, possibly resulting in changes in the flour's functionality such as changes in the gluten quality, vitamin content, and the level of starch gelatinization. There is a need to determine the minimal heat treatment required to achieve desired lethality in flour and other low-moisture foods, with the goal of retaining the flour's functionality. Currently there is no published data about a nonpathogenic bacterial surrogate for Salmonella in flour. In this study, a surrogate, which closely matches the thermal death rate of Salmonella in flour, has been isolated. The surrogate was identified following an evaluation of thermal death curves of ten different strains of bacteria isolated from heat-treated flour and two nonpathogenic surrogates used in other commodities. Flour samples were inoculated with Salmonella or one of the twelve bacterial isolates, and then subjected to heat (70, 75, and 80 °C) for 12-60 min. The heat tolerance for each organism was determined by plating out at least four different time points for each temperature and comparing the death curve to those from Salmonella. The death curve from Pantoea dispersa was not statistically different (p<0.05) than the death curve of Salmonella. This strain of P. dispersa (strain JFS) can be used as a conservative, slightly more heat resistant, surrogate for Salmonella. It can be used to verify the combination of heat and time necessary to kill Salmonella in flour using a commercial heat-treatment process.

  20. Pantoea gaviniae sp. nov. and Pantoea calida sp. nov., isolated from infant formula and an infant formula production environment.

    PubMed

    Popp, Alexandra; Cleenwerck, Ilse; Iversen, Carol; De Vos, Paul; Stephan, Roger

    2010-12-01

    Five Gram-negative, facultatively anaerobic, non-spore-forming, coccoid rod-shaped bacterial isolates were obtained from infant formula and an infant formula production environment and were investigated by use of a polyphasic taxonomic study. Biochemical tests and partial rpoB gene sequence analysis of the five isolates revealed that they formed two distinct groups in the family Enterobacteriaceae, closely related to several species of the genera Pantoea and Erwinia, which indicated a phylogenetic position within the genus Pantoea or the genus Erwinia. Multilocus sequence analysis of concatenated partial atpD, gyrB, infB and rpoB gene sequences of two of the isolates suggested that they represented two novel species of the genus Pantoea, phylogenetically related most closely to Pantoea septica. The five isolates had general characteristics consistent with those of the genus Pantoea, and DNA-DNA hybridizations between two representatives and the type strains of their phylogenetically closest relatives based on comparative 16S rRNA gene sequence analysis showed that the isolates represented two novel genospecies. These two genospecies could be differentiated from each other based on fermentation of galacturonate, sorbitol and potassium 5-ketogluconate. They could be differentiated from phylogenetically related Pantoea species based on their ability to ferment lactose and to utilize β-gentiobiose and raffinose, their inability to ferment or utilize d-arabitol, and their inability to produce indole. On the basis of the results obtained, the five isolates are considered to represent two novel species of the genus Pantoea, for which the names Pantoea gaviniae sp. nov. (type strain A18/07(T) =LMG 25382(T) =DSM 22758(T)) and Pantoea calida sp. nov. (type strain 1400/07(T) =LMG 25383(T) =DSM 22759(T)) are proposed.

  1. Physiologic and metabolic characterization of a new marine isolate (BM39) of Pantoea sp. producing high levels of exopolysaccharide

    PubMed Central

    2013-01-01

    Background Marine environments are the widest fonts of biodiversity representing a resource of both unexploited or unknown microorganisms and new substances having potential applications. Among microbial products, exopolysaccharides (EPS) have many physiological functions and practical applications. Since EPS production by many bacteria is too scarce for practical use and only few species are known for their high levels of production, the search of new high EPS producers is of paramount importance. Many marine bacteria, that produce EPS to cope with strong environmental stress, could be potentially exploited at the industrial level. Results A novel bacterium, strain BM39, previously isolated from sediments collected in the Tyrrhenian Sea, was selected for its production of very high levels of EPS. BM39 was affiliated to Pantoea sp. (Enterobacteriaceae) by 16S rRNA gene sequencing and biochemical tests. According to the phylogenetic tree, this strain, being quite far from the closest known Pantoea species (96% identity with P. agglomerans and P. ananatis) could belong to a new species. EPS production was fast (maximum of ca. 21 g/L in 24 h on glucose medium) and mainly obtained during the exponential growth. Preliminary characterization, carried out by thin layer and gel filtration chromatography, showed that the EPS, being a glucose homopolymer with MW of ca. 830 kDa, appeared to be different from those of other bacteria of same genus. The bacterium showed a typical slightly halophilic behavior growing optimally at NaCl 40 ‰ (growing range 0-100 ‰). Flow cytometry studies indicated that good cell survival was maintained for 24 h at 120 ‰. Survival decreased dramatically with the increase of salinity being only 1 h at 280 ‰. The biochemical characterization, carried out with the Biolog system, showed that MB39 had a rather limited metabolic capacity. Its ability, rather lower than that of P. agglomerans, was almost only confined to the metabolization of

  2. Control of fire blight by Pseudomonas fluorescens A506 and Pantoea vagans C9-1 applied as single strains and mixed inocula

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The biological control agents Pseudomonas fluorescens A506 and Pantoea vagans C9-1 were evaluated individually and in combination for the suppression of fire blight of pear or apple in ten field trials inoculated with the pathogen Erwinia amylovora. The formulation of pathogen inoculum applied to b...

  3. Spondylodiscitis Caused by Enterobacter agglomerans

    PubMed Central

    Kothalawala, Mahen; Devakanthan, Balachandran; Arunan, Sinnappoo; Galgamuwa, Dinithi; Rathnayake, Manori

    2016-01-01

    All over the globe, the incidence of vertebral infection is rising. Nowadays, compared to tuberculous variety, pyogenic spondylodiscitis incidence is high. The increase in the susceptible population and improved diagnostics summatively contributed to this. In clinical grounds, differentiation of pyogenic and tuberculous spondylodiscitis is well defined. Enterobacter agglomerans is a hospital contaminant and associated with infections in immunocompromised individuals and intravenous lines. It causes a wide array of infections. Enterobacter agglomerans spondylodiscitis is unusual and there are, around the globe, only less than 31 suspected cases that have been previously reported. Enterobacter agglomerans histology mimics tuberculous rather than pyogenic spondylodiscitis. A 65-year-old farming lady, while being in hospital, developed sudden onset spastic paraparesis with hyperreflexia. Later blood culture revealed Enterobacter agglomerans with 41-hour incubation in 99.9% probability from Ramel identification system. Her initial ESR was 120 mm/first hour. Isolate was susceptible to ciprofloxacin and intravenous followed with oral therapy shows a drastic ESR fall and improved clinical response. Differentiation of tuberculous and pyogenic spondylodiscitis is very much important in management point of view. Therefore, blood culture has a role in diagnosis of spondylodiscitis. ESR can be used as important inflammatory marker in monitoring the response to treatment. Retrospectively, ESR would aid in reaching a definitive diagnosis. PMID:28127480

  4. Nitrogen-fixing Enterobacter agglomerans isolated from guts of wood-eating termites.

    PubMed Central

    Potrikus, C J; Breznak, J A

    1977-01-01

    Two strains of facultatively anaerobic, N2-fixing bacteria were isolated from guts of Coptotermes formosanus and identified as Enterobacter agglomerans. The deoxyribonucleic acid base composition of isolates was 52.6 and 53.1 mol% guanine plus cytosine. Both isolates and a known strain of E. agglomerans carried out a mixed acid type of glucose fermentation. N2 fixation by E. agglomerans was inhibited by O2; consequently, N2 served as an N source only for cells growing anaerobically in media lacking a major source of combined N. However, peptone, NH4Cl, or KNO3 served as an N source under either aerobic or anaerobic conditions. It was estimated that 2 x 10(2) cells of E. agglomerans were present per termite gut. This value was 100-fold lower than expected, based on N2 fixation, low recoveries of E. agglomerans may be related to the marked decrease in N2 fixation rates observed when intact termites or their extracted guts were manipulated for the isolation of bacteria. It was concluded that the N2-fixing activity of E. agglomerans may be important to the N economy of C. formosanus. PMID:848958

  5. Draft Genome Sequence of the Antibiotic-Producing Epiphytic Isolate Pantoea ananatis BRT175

    PubMed Central

    Smith, Derek D. N.; Kirzinger, Morgan W. B.

    2013-01-01

    Pantoea is a member of the Enterobacteriaceae, whose members have been shown to produce novel antibiotics. Here, we report the 4.8-Mb genome sequence of Pantoea ananatis strain BRT175, an epiphytic isolate from strawberries that produces an antibiotic that is effective against the fire blight pathogen, Erwinia amylovora. PMID:24201193

  6. Comparative Genomic Analysis Reveals Organization, Function and Evolution of ars Genes in Pantoea spp.

    PubMed Central

    Wang, Liying; Wang, Jin; Jing, Chuanyong

    2017-01-01

    Numerous genes are involved in various strategies to resist toxic arsenic (As). However, the As resistance strategy in genus Pantoea is poorly understood. In this study, a comparative genome analysis of 23 Pantoea genomes was conducted. Two vertical genetic arsC-like genes without any contribution to As resistance were found to exist in the 23 Pantoea strains. Besides the two arsC-like genes, As resistance gene clusters arsRBC or arsRBCH were found in 15 Pantoea genomes. These ars clusters were found to be acquired by horizontal gene transfer (HGT) from sources related to Franconibacter helveticus, Serratia marcescens, and Citrobacter freundii. During the history of evolution, the ars clusters were acquired more than once in some species, and were lost in some strains, producing strains without As resistance capability. This study revealed the organization, distribution and the complex evolutionary history of As resistance genes in Pantoea spp.. The insights gained in this study improved our understanding on the As resistance strategy of Pantoea spp. and its roles in the biogeochemical cycling of As. PMID:28377759

  7. Pantoea alhagi, a novel endophytic bacterium with ability to improve growth and drought tolerance in wheat

    PubMed Central

    Chen, Chaoqiong; Xin, Kaiyun; Liu, Hao; Cheng, Juanli; Shen, Xihui; Wang, Yao; Zhang, Lei

    2017-01-01

    A novel strain LTYR-11ZT that exhibited multiple plant growth promoting (PGP) traits was isolated from the surface-sterilized leaves of Alhagi sparsifolia Shap. (Leguminosae), which reprsents one of the top drought tolerant plants in north-west China. Phylogenetic analysis of 16S rRNA gene sequences and multilocus sequence analysis based on partial sequences of atpD, gyrB, infB and rpoB genes revealed that strain LTYR-11ZT was a member of the genus Pantoea, with Pantoea theicola NBRC 110557T and Pantoea intestinalis DSM 28113T as the closest phylogenetic relatives. The results of DNA–DNA hybridization, phenotypic tests and fatty acid analysis confirmed that strain LTYR-11ZT represents a novel species of the genus Pantoea, for which we propose the name Pantoea alhagi sp. nov. Confocal microscopy observation revealed that strain LTYR-11ZT effectively colonizes the rhizoplane of both Arabidopsis and wheat. Strain LTYR-11ZT was able to promote the growth of wheat enhancing its resistance to drought stress. Strain LTYR-11ZT led to increased accumulation of soluble sugars, decreased accumulation of proline and malondialdehyde (MDA), and decreased degradation of chlorophyll in leaves of drought-stressed wheat. Our findings will contribute to the development of a novel biotechnological agent to improve the adaptation of crop plants to drought in arid ecosystems. PMID:28128318

  8. Klebsiella pneumoniae inoculants for enhancing plant growth

    DOEpatents

    Triplett, Eric W.; Kaeppler, Shawn M.; Chelius, Marisa K.

    2008-07-01

    A biological inoculant for enhancing the growth of plants is disclosed. The inoculant includes the bacterial strains Herbaspirillum seropedicae 2A, Pantoea agglomerans P101, Pantoea agglomerans P102, Klebsiella pneumoniae 342, Klebsiella pneumoniae zmvsy, Herbaspirillum seropedicae Z152, Gluconacetobacter diazotrophicus PA15, with or without a carrier. The inoculant also includes strains of the bacterium Pantoea agglomerans and K. pneumoniae which are able to enhance the growth of cereal grasses. Also disclosed are the novel bacterial strains Herbaspirillum seropedicae 2A, Pantoea agglomerans P101 and P102, and Klebsiella pneumoniae 342 and zmvsy.

  9. The large universal Pantoea plasmid LPP-1 plays a major role in biological and ecological diversification

    PubMed Central

    2012-01-01

    Background Pantoea spp. are frequently isolated from a wide range of ecological niches and have various biological roles, as plant epi- or endophytes, biocontrol agents, plant-growth promoters or as pathogens of both plant and animal hosts. This suggests that members of this genus have undergone extensive genotypic diversification. One means by which this occurs among bacteria is through the acquisition and maintenance of plasmids. Here, we have analyzed and compared the sequences of a large plasmid common to all sequenced Pantoea spp. Results and discussion The Large PantoeaPlasmids (LPP-1) of twenty strains encompassing seven different Pantoea species, including pathogens and endo-/epiphytes of a wide range of plant hosts as well as insect-associated strains, were compared. The LPP-1 plasmid sequences range in size from ~281 to 794 kb and carry between 238 and 750 protein coding sequences (CDS). A core set of 46 proteins, encompassing 2.2% of the total pan-plasmid (2,095 CDS), conserved among all LPP-1 plasmid sequences, includes those required for thiamine and pigment biosynthesis. Phylogenetic analysis reveals that these plasmids have arisen from an ancestral plasmid, which has undergone extensive diversification. Analysis of the proteins encoded on LPP-1 also showed that these plasmids contribute to a wide range of Pantoea phenotypes, including the transport and catabolism of various substrates, inorganic ion assimilation, resistance to antibiotics and heavy metals, colonization and persistence in the host and environment, pathogenesis and antibiosis. Conclusions LPP-1 is universal to all Pantoea spp. whose genomes have been sequenced to date and is derived from an ancestral plasmid. LPP-1 encodes a large array of proteins that have played a major role in the adaptation of the different Pantoea spp. to their various ecological niches and their specialization as pathogens, biocontrol agents or benign saprophytes found in many diverse environments. PMID:23151240

  10. Decolorization of azo dyes with Enterobacter agglomerans immobilized in different supports by using fluidized bed bioreactor.

    PubMed

    Moutaouakkil, Adnane; Zeroual, Youssef; Dzayri, Fatima Zohra; Talbi, Mohamed; Lee, Kangmin; Blaghen, Mohamed

    2004-02-01

    Immobilized cells of Enterobacter agglomerans, able to reduce azo dyes enzymatically, were used as a biocatalyst for the decolorization of synthetic medium containing the toxic azo dye methyl red (MR). This bacterial strain exhibits high ability to completely decolorize 100 mg/L of MR after only 6 h of incubation under aerobic conditions. Cells of E. agglomerans were immobilized in calcium alginate, polyacylamide, cooper beech, and vermiculite, and were used for the decolorization of MR from synthetic water by using a fluidized bed bioreactor. The highest specific decolorization rate was obtained when E. agglomerans was entrapped in calcium alginate beads and was of about 3.04 mg MR/g cell/h with a 50% conversion time ( t(1/2)) of about 1.6 h. Moreover, immobilized cells in calcium alginate continuously decolorized MR even after seven repeated experiments without significant loss of activity, while polyacrylamide-, cooper beech-, and vermiculite-immobilized cells retained only 62, 15, and 13% of their original activity, respectively.

  11. Characterization of Alcaligenes faecalis strain AD15 indicating biocontrol activity against plant pathogens.

    PubMed

    Yokoyama, Shin-ichiro; Adachi, Yoshitomi; Asakura, Shuichi; Kohyama, Erina

    2013-01-01

    Bacterial strain possessing both bacteriostatic and fungistatic activity (biocontrol activity) against pathogens of cyclamen (Cyclamen sp.) was isolated from the soil in Gifu Prefecture, Japan, and characterized with respect to its taxonomic and biocontrol properties. The sequence of its 16S rRNA gene, morphology, biochemistry, and fatty acid composition demonstrated that it is a strain most closely related to Alcaligenes faecalis subsp. faecalis LMG 1229(T). The isolate was named A. faecalis strain AD15. A. faecalis AD15 produced hydroxylamine at maximum yields of 33.3±1.7 mg/L after 16 h cultivation in LB medium and 19.0±0.44 mg/L after 19 h cultivation in synthetic medium. Moreover, minimum inhibitory concentrations of hydroxylamine against the cyclamen pathogens Pantoea agglomerans and Colletotrichum gloeosporioides were 4.20±0.98 and 16.5±0.67 mg/L. These results indicated that the biocontrol activity of strain AD15 might be attributed to hydroxylamine, a metabolite in the culture medium, and it had the potential for biopesticide application.

  12. Transmission of the opportunistic cotton (Gossypium hirsutum L.) boll pathogen Pantoea agglomerans by the brown stink bug (Euschistus servus Say)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Damage to developing cotton bolls by piercing-sucking insects such as stink bugs has traditionally been attributed solely to pest feeding. Previously, we showed clear differences in severity of boll damage resulting from southern green stink bug (Nezara viridula L.) fed sterile food compared to thos...

  13. Relationship between the physiology of Enterobacter agglomerans CNCM 1210 grown anaerobically on glycerol and the culture conditions.

    PubMed

    Barbirato, F; Bories, A

    1997-01-01

    In a preliminary study, levels of activity of enzymes involved in anaerobic glycerol catabolism by Enterobacter agglomerans grown in batch cultures regulated in a pH range of 6.5-8.0 were monitored. That study showed that activities of key enzymes of the downstream metabolism of glycerol--glyceradehyde-3-phosphate dehydrogenase (GAP-DH), lactate dehydrogenase and pyruvate formate lyase--were strongly dependent on the culture pH. To investigate the influence of pH on the physiology of the strain, E. agglomerans was grown anaerobically in a continuous culture supplied with glycerol as the sole carbon source and regulated at pH 8. A complete biochemical analysis was performed and was compared with that previously described for the continuous culture regulated at pH 7. A limitation of the glycolytic flux at the level of GAP-DH was demonstrated at high dilution rate, resulting in an overflow metabolism through the 1,3-propanediol formation pathway. Increasing the specific rate of glycerol consumption also resulted in enhanced lactate production due to limitation by the pyruvate decarboxylation step. Finally, changing the culture pH significantly modified the enzymatic profile of E. agglomerans, and it enabled the stability of the culture to be increased by preventing the accumulation in the fermentation broth of 3-hydroxypropionaldehyde, an inhibitory metabolite, when the glycerol supply was suddenly increased.

  14. Raman chemical imaging of the rhizosphere bacterium Pantoea sp. YR343 and its co-culture with Arabidopsis thaliana

    SciTech Connect

    Polisetti, Sneha; Bible, Amber N.; Morrell-Falvey, Jennifer L.; Bohn, Paul W.

    2016-02-29

    Chemical imaging of plant-bacteria co-cultures renders it possible to characterize bacterial populations and behaviors and their interactions with proximal organisms, under conditions closest to the environment in the rhizosphere. Here Raman micro-spectroscopy and confocal Raman imaging are used as minimally invasive probes to study the rhizosphere bacterial isolate, Pantoea sp. YR343, and its co-culture with model plant Arabidopsis thaliana by combining enhanced Raman spectroscopies with electron microscopy and principal component analysis (PCA). The presence of carotenoid pigments in the wild type Pantoea sp. YR343 was characterized using resonance Raman scattering, which was also used to confirm successful disruption of the crtB gene in an engineered carotenoid mutant strain. Other components of the Pantoea sp. YR343 cells were imaged in the presence of resonantly enhanced pigments using a combination of surface enhanced Raman imaging and PCA. Pantoea sp. YR343 cells decorated with Ag colloid synthesized ex situ gave spectra dominated by carotenoid scattering, whereas colloids synthesized in situ produced spectral signatures characteristic of flavins in the cell membrane. Scanning electron microscopy (SEM) of whole cells and transmission electron microscopy (TEM) images of thinly sliced cross-sections were used to assess structural integrity of the coated cells and to establish the origin of spectral signatures based on the position of Ag nanoparticles in the cells. Finally, raman imaging was also used to characterize senescent green Arabidopsis thaliana plant roots inoculated with Pantoea sp. YR343, and PCA was used to distinguish spectral contributions from plant and bacterial cells, thereby establishing the potential of Raman imaging to visualize the distribution of rhizobacteria on plant roots.

  15. Raman chemical imaging of the rhizosphere bacterium Pantoea sp. YR343 and its co-culture with Arabidopsis thaliana

    DOE PAGES

    Polisetti, Sneha; Bible, Amber N.; Morrell-Falvey, Jennifer L.; ...

    2016-02-29

    Chemical imaging of plant-bacteria co-cultures renders it possible to characterize bacterial populations and behaviors and their interactions with proximal organisms, under conditions closest to the environment in the rhizosphere. Here Raman micro-spectroscopy and confocal Raman imaging are used as minimally invasive probes to study the rhizosphere bacterial isolate, Pantoea sp. YR343, and its co-culture with model plant Arabidopsis thaliana by combining enhanced Raman spectroscopies with electron microscopy and principal component analysis (PCA). The presence of carotenoid pigments in the wild type Pantoea sp. YR343 was characterized using resonance Raman scattering, which was also used to confirm successful disruption of themore » crtB gene in an engineered carotenoid mutant strain. Other components of the Pantoea sp. YR343 cells were imaged in the presence of resonantly enhanced pigments using a combination of surface enhanced Raman imaging and PCA. Pantoea sp. YR343 cells decorated with Ag colloid synthesized ex situ gave spectra dominated by carotenoid scattering, whereas colloids synthesized in situ produced spectral signatures characteristic of flavins in the cell membrane. Scanning electron microscopy (SEM) of whole cells and transmission electron microscopy (TEM) images of thinly sliced cross-sections were used to assess structural integrity of the coated cells and to establish the origin of spectral signatures based on the position of Ag nanoparticles in the cells. Finally, raman imaging was also used to characterize senescent green Arabidopsis thaliana plant roots inoculated with Pantoea sp. YR343, and PCA was used to distinguish spectral contributions from plant and bacterial cells, thereby establishing the potential of Raman imaging to visualize the distribution of rhizobacteria on plant roots.« less

  16. Draft Genome Sequence of Pantoea ananatis GB1, a Plant-Growth-Promoting Hydrocarbonoclastic Root Endophyte, Isolated at a Diesel Fuel Phytoremediation Site Planted with Populus

    PubMed Central

    Gkorezis, Panagiotis; Van Hamme, Jonathan D.; Bottos, Eric M.; Thijs, Sofie; Balseiro-Romero, Maria; Monterroso, Carmela; Kidd, Petra Suzan; Rineau, Francois; Weyens, Nele

    2016-01-01

    We report the 4.76-Mb draft genome of Pantoea ananatis GB1, a Gram-negative bacterium of the family Enterobacteriaceae, isolated from the roots of poplars planted for phytoremediation of a diesel-contaminated plume at the Ford Motor Company site in Genk, Belgium. Strain GB1 promotes plant growth in various hosts and metabolizes hydrocarbons. PMID:26950324

  17. Cotton (Gossypium hirsutum L.) boll rotting bacteria vectored by the brown stink bug, Euschistus servus (Say) (Hemiptera: Pentatomidea)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Determine the capacity of the brown stink bug (Euschistus servus) to transmit an infective Pantoea agglomerans into cotton (Gossypium hirsutum, L.) bolls. A laboratory colony of the brown stink bug (BSB) was maintained on fresh green beans. The P. agglomerans mutant strain Sc 1-R that holds rifamp...

  18. Different Flour Microbial Communities Drive to Sourdoughs Characterized by Diverse Bacterial Strains and Free Amino Acid Profiles

    PubMed Central

    Celano, Giuseppe; De Angelis, Maria; Minervini, Fabio; Gobbetti, Marco

    2016-01-01

    This work aimed to investigate whether different microbial assemblies in flour may influence the microbiological and biochemical characteristics of traditional sourdough. To reach this purpose, members of lactic acid bacteria, enterobacteria, and yeasts were isolated from durum wheat flour. Secondly, the isolated microorganisms (Pediococcus pentosaceus, Saccharomyces cerevisiae, Pantoea agglomerans, and Escherichia hermannii) were inoculated in doughs prepared with irradiated flour (gamma rays at 10 kGy), so that eight different microbial assemblies were obtained. Two non-inoculated controls were prepared, one of which (C-IF) using irradiated flour and the other (C) using non-irradiated flour. As shown by plate counts, irradiation of flour caused total inactivation of yeasts and a decrease of all the other microbial populations. However, acidification occurred also in the dough C-IF, due to metabolic activity of P. pentosaceus that had survived irradiation. After six fermentations, P. pentosaceus was the dominant lactic acid bacterium species in all the sourdoughs produced with irradiated flour (IF). Yet, IF-based sourdoughs broadly differed from each other in terms of strains of P. pentosaceus, probably due to the different microorganisms initially inoculated. Quantitative and qualitative differences of free amino acids concentration were found among the sourdoughs, possibly because of different microbial communities. In addition, as shown by culture-independent analysis (16S metagenetics), irradiation of flour lowered and modified microbial diversity of sourdough ecosystem. PMID:27877165

  19. Arsenite oxidation by Alcaligenes sp. strain RS-19 isolated from arsenic-contaminated mines in the Republic of Korea.

    PubMed

    Yoon, In-Ho; Chang, Jin-Soo; Lee, Ji-Hoon; Kim, Kyoung-Woong

    2009-02-01

    Arsenite [As(III)]-oxidizing bacteria play important roles in reducing arsenic [As] toxicity and mobility in As-contaminated areas. As-resistant bacteria were isolated from the soils of two abandoned mines in the Republic of Korea. The isolated bacteria showed relatively high resistances to As(III) up to 26 mM. The PCR-based 16S rRNA analysis revealed that the isolated As-resistant bacteria were close relatives to Serratia marcescensa, Pseudomonas putida, Pantoea agglomerans, and Alcaligenes sp. Among the five As-resistant bacterial isolates, Alcaligenes sp. strain RS-19 showed the highest As(III)-oxidizing activity in batch tests, completely oxidizing 1 mM of As(III) to As(V) within 40 h during heterotrophic growth. This study suggests that the indigenous bacteria have evolved to retain the ability to resist toxic As in the As-contaminated environments and moreover to convert the species to a less toxic form [e.g., from As(III) to As(V)] and also contribute the biogeochemical cycling of As by being involved in speciation of As.

  20. GST activity and membrane lipid saturation prevents mesotrione-induced cellular damage in Pantoea ananatis.

    PubMed

    Prione, Lilian P; Olchanheski, Luiz R; Tullio, Leandro D; Santo, Bruno C E; Reche, Péricles M; Martins, Paula F; Carvalho, Giselle; Demiate, Ivo M; Pileggi, Sônia A V; Dourado, Manuella N; Prestes, Rosilene A; Sadowsky, Michael J; Azevedo, Ricardo A; Pileggi, Marcos

    2016-12-01

    Callisto(®), containing the active ingredient mesotrione (2-[4-methylsulfonyl-2-nitrobenzoyl]1,3-cyclohenanedione), is a selective herbicide that controls weeds in corn crops and is a potential environmental contaminant. The objective of this work was to evaluate enzymatic and structural changes in Pantoea ananatis, a strain isolated from water, in response to exposure to this herbicide. Despite degradation of mesotrione, probably due a glutathione-S-transferase (GST) pathway in Pantoea ananatis, this herbicide induced oxidative stress by increasing hydrogen peroxide production. Thiol fragments, eventually produced after mesotrione degradation, could be involved in increased GST activity. Nevertheless, there was no peroxidation damage related to this production, as malondialdehyde (MDA) synthesis, which is due to lipid peroxidation, was highest in the controls, followed by the mesotrione- and Callisto(®)-treated cultures at log growth phase. Therefore, P. ananatis can tolerate and grow in the presence of the herbicide, probably due an efficient control of oxidative stress by a polymorphic catalase system. MDA rates depend on lipid saturation due to a pattern change to a higher level of saturation. These changes are likely related to the formation of GST-mesotrione conjugates and mesotrione degradation-specific metabolites and to the presence of cytotoxic adjuvants. These features may shift lipid membrane saturation, possibly providing a protective effect to bacteria through an increase in membrane impermeability. This response system in P. ananatis provides a novel model for bacterial herbicide tolerance and adaptation in the environment.

  1. Characterization of two LuxI/R homologs in Pantoea ananatis LMG 2665(T).

    PubMed

    Sibanda, Siphathele; Theron, Jacques; Shyntum, Divine Y; Moleleki, Lucy N; Coutinho, Teresa A

    2016-11-01

    Quorum sensing (QS) plays an important role in the regulation of bacteria-host interactions and ecological fitness in many bacteria. In this study, 2 luxI/R homologs, namely eanI/eanR and rhlI/rhlR, were identified in the genome sequence of Pantoea ananatis LMG 2665(T). To determine a role for these luxI/R homologs in pathogenicity and biofilm formation, mutant bacterial strains lacking either eanI/R or rhlI/R and both of these homologs were generated. The results indicated that both the RhlI/R and EanI/R systems are required for pathogenicity and biofilm formation in strain LMG 2665(T). This is the first study to characterize the biological significance of the RhlI/R QS system in P. ananatis.

  2. Diversity of culturable bacteria including Pantoea in wild mosquito Aedes albopictus

    PubMed Central

    2013-01-01

    Background The microbiota has been shown to play an important role in the biology of insects. In recent decades, significant efforts have been made to better understand the diversity of symbiotic bacteria associated with mosquitoes and assess their influence on pathogen transmission. Here, we report the bacterial composition found in field-caught Aedes albopictus populations by using culture-dependent methods. Results A total of 104 mosquito imagos (56 males and 48 females) were caught from four contrasting biotopes of Madagascar and their bacterial contents were screened by plating whole body homogenates on three different culture media. From 281 bacterial colony types obtained, amplified ribosomal DNA restriction analysis (ARDRA) showed they had 40 distinct ribotypes. Sequencing and BLAST analysis of the 16S rDNA genes responsible for each representative profile made it possible to identify 27 genera distributed in three major phyla. In female mosquitoes, bacterial isolates were mostly Proteobacteria (51.3%) followed by Firmicutes (30.3%) and Actinobacteria (18.4%). Conversely, Actinobacteria was the most abundant phylum in male mosquitoes (48%) followed by Proteobacteria (30.6%) and Firmicutes (20.4%). The relative abundance and composition of isolates also varied between sampling sites, ranging from 3 distinct families in Ankazobe to 8 in Tsimbazaza Park, and Toamasina and Ambohidratrimo. Pantoea was the most common genus in both females and males from all sampling sites, except for Ambohidratrimo. No differences in genome size were found between Pantoea isolates from mosquitoes and reference strains in pulse field gel electrophoresis. However, according to the numbers and sizes of plasmids, mosquito isolates clustered into three different groups with other strains isolated from insects but distinct from isolates from the environment. Conclusions The recent upsurge in research into the functional role of the insect microbiota prompts the interest to better

  3. A Novel Glycolipid Biosurfactant Confers Grazing Resistance upon Pantoea ananatis BRT175 against the Social Amoeba Dictyostelium discoideum

    PubMed Central

    Smith, Derek D. N.; Nickzad, Arvin

    2016-01-01

    ABSTRACT Pantoea is a versatile genus of bacteria with both plant- and animal-pathogenic strains, some of which have been suggested to cause human infections. There is, however, limited knowledge on the potential determinants used for host association and pathogenesis in animal systems. In this study, we used the model host Dictyostelium discoideum to show that isolates of Pantoea ananatis exhibit differential grazing susceptibility, with some being resistant to grazing by the amoebae. We carried out a high-throughput genetic screen of one grazing-resistant isolate, P. ananatis BRT175, using the D. discoideum pathosystem to identify genes responsible for the resistance phenotype. Among the 26 candidate genes involved in grazing resistance, we identified rhlA and rhlB, which we show are involved in the biosynthesis of a biosurfactant that enables swarming motility in P. ananatis BRT175. Using liquid chromatography-mass spectrometry (LC-MS), the biosurfactant was shown to be a glycolipid with monohexose-C10-C10 as the primary congener. We show that this novel glycolipid biosurfactant is cytotoxic to the amoebae and is capable of compromising cellular integrity, leading to cell lysis. The production of this biosurfactant may be important for bacterial survival in the environment and could contribute to the establishment of opportunistic infections. IMPORTANCE The genetic factors used for host interaction by the opportunistic human pathogen Pantoea ananatis are largely unknown. We identified two genes that are important for the production of a biosurfactant that confers grazing resistance against the social amoeba Dictyostelium discoideum. We show that the biosurfactant, which exhibits cytotoxicity toward the amoebae, is a glycolipid that incorporates a hexose rather than rhamnose. The production of this biosurfactant may confer a competitive advantage in the environment and could potentially contribute to the establishment of opportunistic infections. PMID

  4. High saturated fatty acids proportion in Escherichia coli enhances the activity of ice-nucleation protein from Pantoea ananatis.

    PubMed

    Yu, Feifei; Liu, Xiping; Tao, Yong; Zhu, Kun

    2013-08-01

    The ice-nucleation protein (INP) from Pantoea ananatis was expressed in Escherichia coli. INP expression increased the freezing point of the E. coli culture by a few degrees. Deletion of FabH, an important enzyme in fatty acid biosynthesis, significantly inhibited the ice-nucleation activity. Increased unsaturated fatty acids in the fabH mutant cells decreased the ice-nucleation activity. Adding exogenous saturated fatty acids increased both E. coli fatty acid saturation and the ice-nucleation activity. In contrast, adding unsaturated fatty acids exhibited the opposite effects. Furthermore, an E. coli MG1655-fadR strain with high saturated fatty acids content was constructed, in which the INP activity was enhanced by about 17% compared with its activity in the wild-type MG1655 strain.

  5. [Enterobacter agglomerans B1 producing beta-galactosidase with transglycosylation activity: screening, identification, fermentation conditions, and galacto-oligosaccharides synthesis].

    PubMed

    Lu, Lili; Xiao, Min; Xu, Xiaodong

    2008-01-01

    Galacto-oligosaccharides (GOS) are promising non-digestible oligosaccharides recognized as prebiotics. Commercial GOS containing galactose as subunit, are synthesized from lactose using the galactosyl-transferase activity of beta-galactosidase. A strain producing beta-galactosidase with transglycosylation activity was screened from the soil. Phenotypic analysis including morphology and physiology characteristics and 16S rDNA sequence analysis were carried out. Based on taxonomy results, the strain was identified as Enterobacter agglomerans B1. Medium and fermentation conditions were optimized by single factor and orthogonal experiments. The enzyme reached 9.7 U/mL in the medium (pH 7.5) containing 1% lactose, 1% yeast extract, and 0.5% peptone when cultured at 25 degrees C for 26 h. Effects of pH, temperature, lactose concentration, and reaction time on transgalactosylation by whole cells were studied. Yield of GOS reached 40.7% in 30% lactose (pH 7.5) at 50 degrees C for 12 h, as analyzed by HPLC and TLC. The results of an MS analysis showed that GOS were composed of di, tri-, and tetrasaccharides.

  6. Identification of a Pantoea Biosynthetic Cluster That Directs the Synthesis of an Antimicrobial Natural Product

    PubMed Central

    Walterson, Alyssa M.; Smith, Derek D. N.; Stavrinides, John

    2014-01-01

    Fire Blight is a destructive disease of apple and pear caused by the enteric bacterial pathogen, Erwinia amylovora. E. amylovora initiates infection by colonizing the stigmata of apple and pear trees, and entering the plants through natural openings. Epiphytic populations of the related enteric bacterium, Pantoea, reduce the incidence of disease through competition and antibiotic production. In this study, we identify an antibiotic from Pantoea ananatis BRT175, which is effective against E. amylovora and select species of Pantoea. We used transposon mutagenesis to create a mutant library, screened approximately 5,000 mutants for loss of antibiotic production, and recovered 29 mutants. Sequencing of the transposon insertion sites of these mutants revealed multiple independent disruptions of an 8.2 kb cluster consisting of seven genes, which appear to be coregulated. An analysis of the distribution of this cluster revealed that it was not present in any other of our 115 Pantoea isolates, or in any of the fully sequenced Pantoea genomes, and is most closely related to antibiotic biosynthetic clusters found in three different species of Pseudomonas. This identification of this biosynthetic cluster highlights the diversity of natural products produced by Pantoea. PMID:24796857

  7. Metabolic Versatility and Antibacterial Metabolite Biosynthesis Are Distinguishing Genomic Features of the Fire Blight Antagonist Pantoea vagans C9-1

    PubMed Central

    Smits, Theo H. M.; Rezzonico, Fabio; Kamber, Tim; Blom, Jochen; Goesmann, Alexander; Ishimaru, Carol A.; Frey, Jürg E.; Stockwell, Virginia O.; Duffy, Brion

    2011-01-01

    Background Pantoea vagans is a commercialized biological control agent used against the pome fruit bacterial disease fire blight, caused by Erwinia amylovora. Compared to other biocontrol agents, relatively little is currently known regarding Pantoea genetics. Better understanding of antagonist mechanisms of action and ecological fitness is critical to improving efficacy. Principal Findings Genome analysis indicated two major factors contribute to biocontrol activity: competition for limiting substrates and antibacterial metabolite production. Pathways for utilization of a broad diversity of sugars and acquisition of iron were identified. Metabolism of sorbitol by P. vagans C9-1 may be a major metabolic feature in biocontrol of fire blight. Biosynthetic genes for the antibacterial peptide pantocin A were found on a chromosomal 28-kb genomic island, and for dapdiamide E on the plasmid pPag2. There was no evidence of potential virulence factors that could enable an animal or phytopathogenic lifestyle and no indication of any genetic-based biosafety risk in the antagonist. Conclusions Identifying key determinants contributing to disease suppression allows the development of procedures to follow their expression in planta and the genome sequence contributes to rationale risk assessment regarding the use of the biocontrol strain in agricultural systems. PMID:21789243

  8. An In-depth Analysis of a Multilocus Phylogeny Identifies leuS As a Reliable Phylogenetic Marker for the Genus Pantoea

    PubMed Central

    Tambong, James T; Xu, Renlin; Kaneza, Cynthia-Anne; Nshogozabahizi, Jean-Claude

    2014-01-01

    Partial sequences of six core genes (fusA, gyrB, leuS, pyrG, rlpB, and rpoB) of 37 strains of Pantoea species were analyzed in order to obtain a comprehensive view regarding the phylogenetic relationships within the Pantoea genus and compare tree topologies to identify gene(s) for reliable species and subspecies differentiation. All genes used in this study were effective at species-level delineation, but the internal nodes represented conflicting common ancestors in fusA- and pyrG-based phylogenies. Concatenated gene phylogeny gave the expected DNA relatedness, underscoring the significance of a multilocus sequence analysis. Pairwise comparison of topological distances and percent similarities indicated a significant differential influence of individual genes on the concatenated tree topology. leuS- and fusA-inferred phylogenies exhibited, respectively, the lowest (4) and highest (52) topological distances to the concatenated tree. These correlated well with high (96.3%) and low (64.4%) percent similarities of leuS- and fusA-inferred tree topologies to the concatenated tree, respectively. We conclude that the concatenated tree topology is strongly influenced by the gene with the highest number of polymorphic and non-synonymous sites in the absence of significant recombination events. PMID:25125967

  9. Comparative genomics of the type VI secretion systems of Pantoea and Erwinia species reveals the presence of putative effector islands that may be translocated by the VgrG and Hcp proteins

    PubMed Central

    2011-01-01

    Background The Type VI secretion apparatus is assembled by a conserved set of proteins encoded within a distinct locus. The putative effector proteins Hcp and VgrG are also encoded within these loci. We have identified numerous distinct Type VI secretion system (T6SS) loci in the genomes of several ecologically diverse Pantoea and Erwinia species and detected the presence of putative effector islands associated with the hcp and vgrG genes. Results Between two and four T6SS loci occur among the Pantoea and Erwinia species. While two of the loci (T6SS-1 and T6SS-2) are well conserved among the various strains, the third (T6SS-3) locus is not universally distributed. Additional orthologous loci are present in Pantoea sp. aB-valens and Erwinia billingiae Eb661. Comparative analysis of the T6SS-1 and T6SS-3 loci showed non-conserved islands associated with the vgrG and hcp, and vgrG genes, respectively. These regions had a G+C content far lower than the conserved portions of the loci. Many of the proteins encoded within the hcp and vgrG islands carry conserved domains, which suggests they may serve as effector proteins for the T6SS. A number of the proteins also show homology to the C-terminal extensions of evolved VgrG proteins. Conclusions Extensive diversity was observed in the number and content of the T6SS loci among the Pantoea and Erwinia species. Genomic islands could be observed within some of T6SS loci, which are associated with the hcp and vgrG proteins and carry putative effector domain proteins. We propose new hypotheses concerning a role for these islands in the acquisition of T6SS effectors and the development of novel evolved VgrG and Hcp proteins. PMID:22115407

  10. Characterization of a Pantoea stewartii TTSS gene required for persistence in its flea beetle vector

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stewart's bacterial wilt of maize is caused by Pantoea stewartii subsp. stewartii (Pnss), a bacterium that is transmitted by the flea beetle, Chaetocnema pulicaria. Few studies have focused on the molecular basis of the interactions of Pnss with its vector. Genome analyses indicated that Pnss carri...

  11. ISOLATION OF AN OPERON INVOLVED IN XYLITOL METABOLISM FROM PANTOEA ANANATIS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An operon involved in xylitol metabolism in a xylitol-utilizing Pantoea ananatis mutant was cloned by the transposon tagging method. Sequencing analysis revealed that seven consecutive open reading frames (ORFs) are located in the same strand (xytA-G). Sequence homology search suggested that the o...

  12. Quorum-sensing regulation governs bacterial adhesion, biofilm development, and host colonization in Pantoea stewartii subspecies stewartii

    PubMed Central

    Koutsoudis, Maria D.; Tsaltas, Dimitrios; Minogue, Timothy D.; von Bodman, Susanne B.

    2006-01-01

    The phytopathogenic bacterium Pantoea stewartii subsp. stewartii synthesizes stewartan exo/capsular polysaccharide (EPS) in a cell density-dependent manner governed by the EsaI/EsaR quorum-sensing (QS) system. This study analyzes biofilm development and host colonization of the WT and QS regulatory mutant strains of P. stewartii. First, we show that the cell density-dependent synthesis of stewartan EPS, governed by the EsaI/EsaR QS system, is required for proper bacterial adhesion and development of spatially defined, 3D biofilms. Second, a nonvirulent mutant lacking the esaI gene adheres strongly to surfaces and develops densely packed, less structurally defined biofilms in vitro. This strain appears to be arrested in a low cell density developmental mode. Exposure of this strain to exogenous N-acyl-homoserine lactone counteracts this adhesion phenotype. Third, QS mutants lacking the EsaR repressor attach poorly to surfaces and form amorphous biofilms heavily enmeshed in excess EPS. Fourth, the WT strain disseminates efficiently within the xylem, primarily in a basipetal direction. In contrast, the two QS mutant strains remain largely localized at the site of infection. Fifth, and most significantly, epifluorescence microscopic imaging of infected leaf tissue and excised xylem vessels reveals that the bacteria colonize the xylem with unexpected specificity, particularly toward the annular rings and spiral secondary wall thickenings of protoxylem, as opposed to indiscriminate growth to fill the xylem lumen. These observations are significant to bacterial plant pathogenesis in general and may reveal targets for disease control. PMID:16585516

  13. Isolation and Characterization of Rhamnolipid-Producing Bacterial Strains from a Biodiesel Facility

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Novel strains of rhamnolipid-producing bacteria were isolated from soils at a biodiesel facility on the basis of their ability to grow on glycerol as a sole carbon source. Strains were identified as Acinetobacter calcoaceticus, Enterobacter asburiae, E. hormaecheii, Pantoea stewartii and Pseudomona...

  14. Pantoea sp. isolated from tropical fresh water exhibiting N-acyl homoserine lactone production.

    PubMed

    Tan, Wen-Si; Muhamad Yunos, Nina Yusrina; Tan, Pui-Wan; Mohamad, Nur Izzati; Adrian, Tan-Guan-Sheng; Yin, Wai-Fong; Chan, Kok-Gan

    2014-01-01

    N-Acyl homoserine lactone (AHL) serves as signaling molecule for quorum sensing (QS) in Gram-negative bacteria to regulate various physiological activities including pathogenicity. With the aim of isolating freshwater-borne bacteria that can cause outbreak of disease in plants and portrayed QS properties, environmental water sampling was conducted. Here we report the preliminary screening of AHL production using Chromobacterium violaceum CV026 and Escherichia coli [pSB401] as AHL biosensors. The 16S rDNA gene sequence of isolate M009 showed the highest sequence similarity to Pantoea stewartii S9-116, which is a plant pathogen. The isolated Pantoea sp. was confirmed to produce N-3-oxohexanoyl-L-HSL (3-oxo-C6-HSL) through analysis of high resolution mass tandem mass spectrometry.

  15. Arsenic resistance strategy in Pantoea sp. IMH: Organization, function and evolution of ars genes

    PubMed Central

    Wang, Liying; Zhuang, Xuliang; Zhuang, Guoqiang; Jing, Chuanyong

    2016-01-01

    Pantoea sp. IMH is the only bacterium found in genus Pantoea with a high As resistance capacity, but its molecular mechanism is unknown. Herein, the organization, function, and evolution of ars genes in IMH are studied starting with analysis of the whole genome. Two ars systems - ars1 (arsR1B1C1H1) and ars2 (arsR2B2C2H2) - with low sequence homology and two arsC-like genes, were found in the IMH genome. Both ars1 and ars2 are involved in the As resistance, where ars1 is the major contributor at 15 °C and ars2 at 30 °C. The difference in the behavior of these two ars systems is attributed to the disparate activities of their arsR promoters at different temperatures. Sequence analysis based on concatenated ArsRBC indicates that ars1 and ars2 clusters may be acquired from Franconibacter helveticus LMG23732 and Serratia marcescens (plasmid R478), respectively, by horizontal gene transfer (HGT). Nevertheless, two arsC-like genes, probably arising from the duplication of arsC, do not contribute to the As resistance. Our results indicate that Pantoea sp. IMH acquired two different As resistance genetic systems by HGT, allowing the colonization of changing ecosystems, and highlighting the flexible adaptation of microorganisms to resist As. PMID:27966630

  16. The genomes of closely related Pantoea ananatis maize seed endophytes having different effects on the host plant differ in secretion system genes and mobile genetic elements

    PubMed Central

    Sheibani-Tezerji, Raheleh; Naveed, Muhammad; Jehl, Marc-André; Sessitsch, Angela; Rattei, Thomas; Mitter, Birgit

    2015-01-01

    The seed as a habitat for microorganisms is as yet under-explored and has quite distinct characteristics as compared to other vegetative plant tissues. In this study, we investigated three closely related P. ananatis strains (named S6, S7, and S8), which were isolated from maize seeds of healthy plants. Plant inoculation experiments revealed that each of these strains exhibited a different phenotype ranging from weak pathogenic (S7), commensal (S8), to a beneficial, growth-promoting effect (S6) in maize. We performed a comparative genomics analysis in order to find genetic determinants responsible for the differences observed. Recent studies provided exciting insight into the genetic drivers of niche adaption and functional diversification of the genus Pantoea. However, we report here for the first time on the analysis of P. ananatis strains colonizing the same ecological niche but showing distinct interaction strategies with the host plant. Our comparative analysis revealed that genomes of these three strains are highly similar. However, genomic differences in genes encoding protein secretion systems and putative effectors, and transposase/integrases/phage related genes could be observed. PMID:26029184

  17. The genomes of closely related Pantoea ananatis maize seed endophytes having different effects on the host plant differ in secretion system genes and mobile genetic elements.

    PubMed

    Sheibani-Tezerji, Raheleh; Naveed, Muhammad; Jehl, Marc-André; Sessitsch, Angela; Rattei, Thomas; Mitter, Birgit

    2015-01-01

    The seed as a habitat for microorganisms is as yet under-explored and has quite distinct characteristics as compared to other vegetative plant tissues. In this study, we investigated three closely related P. ananatis strains (named S6, S7, and S8), which were isolated from maize seeds of healthy plants. Plant inoculation experiments revealed that each of these strains exhibited a different phenotype ranging from weak pathogenic (S7), commensal (S8), to a beneficial, growth-promoting effect (S6) in maize. We performed a comparative genomics analysis in order to find genetic determinants responsible for the differences observed. Recent studies provided exciting insight into the genetic drivers of niche adaption and functional diversification of the genus Pantoea. However, we report here for the first time on the analysis of P. ananatis strains colonizing the same ecological niche but showing distinct interaction strategies with the host plant. Our comparative analysis revealed that genomes of these three strains are highly similar. However, genomic differences in genes encoding protein secretion systems and putative effectors, and transposase/integrases/phage related genes could be observed.

  18. Cloning and characterization of 5-enopyruvylshikimate-3-phosphate synthase from Pantoea sp.

    PubMed

    Liu, F; Cao, Y P

    2015-12-29

    The shikimate pathway enzyme 5-enopyruvylshikimate-3-phosphate synthase (EPSPS) is the target of the broad spectrum herbicide glyphosate. A novel aroA gene encoding an EPSPS from Pantoea sp was identified and subcloned into the pET-28a vector to construct the recombinant pET-AroAPantoea sp plasmid. Amino acid sequence analysis indicated that AroAPantoea sp is a class I AroA enzyme. When expressed in Escherichia coli, it conveyed high tolerance to glyphosate. AroAPantoea sp may be used to generate transgenic glyphosate-tolerant plants.

  19. A novel l-isoleucine-4′-dioxygenase and l-isoleucine dihydroxylation cascade in Pantoea ananatis

    PubMed Central

    Smirnov, Sergey V; Sokolov, Pavel M; Kotlyarova, Veronika A; Samsonova, Natalya N; Kodera, Tomohiro; Sugiyama, Masakazu; Torii, Takayoshi; Hibi, Makoto; Shimizu, Sakayu; Yokozeki, Kenzo; Ogawa, Jun

    2013-01-01

    A unique operon structure has been identified in the genomes of several plant- and insect-associated bacteria. The distinguishing feature of this operon is the presence of tandem hilA and hilB genes encoding dioxygenases belonging to the PF13640 and PF10014 (BsmA) Pfam families, respectively. The genes encoding HilA and HilB from Pantoea ananatis AJ13355 were cloned and expressed in Escherichia coli. The culturing of E. coli cells expressing hilA (E. coli-HilA) or both hilA and hilB (E. coli-HilAB) in the presence of l-isoleucine resulted in the conversion of l-isoleucine into two novel biogenic compounds: l-4′-isoleucine and l-4,4′-dihydroxyisoleucine, respectively. In parallel, two novel enzymatic activities were detected in the crude cell lysates of the E. coli-HilA and E. coli-HilAB strains: l-isoleucine, 2-oxoglutarate: oxygen oxidoreductase (4′-hydroxylating) (HilA) and l-4′-hydroxyisoleucine, 2-oxoglutarate: oxygen oxidoreductase (4-hydroxylating) (HilB), respectively. Two hypotheses regarding the physiological significance of C-4(4′)-hydroxylation of l-isoleucine in bacteria are also discussed. According to first hypothesis, the l-isoleucine dihydroxylation cascade is involved in synthesis of dipeptide antibiotic in P. ananatis. Another unifying hypothesis is that the C-4(4′)-hydroxylation of l-isoleucine in bacteria could result in the synthesis of signal molecules belonging to two classes: 2(5H)-furanones and analogs of N-acyl homoserine lactone. PMID:23554367

  20. Transmission and Importance of Pantoea ananatis During Feeding on Cotton Buds (Gossypium hirsutum L.) by Cotton Fleahoppers (Pseudatomoscelis seriatus Reuter)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton fleahoppers collected from various hosts in the field or raised on green beans in the laboratory were frequently infested with Pantoea spp. These isolates caused a severe internal boll rot in cotton when introduced into young bolls via a small puncture wound caused by a 28-gauge needle. Bud...

  1. Potential transmission of Pantoea spp. and Serratia marcescens (Enterobacteriales: Enterobacteriaceae) to plants by Lygus hesperus (Hemiptera: Miridae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lygus hesperus Knight (Hemiptera: Miridae) is a key agricultural pest in the western United States. In a recent study, proteins from Pantoea ananatis and Serratia marcescens (Enterobacteriales: Enterobacteriaceae) were identified in diet that was stylet-probed and fed upon by L. hesperus adults. P...

  2. Duplex TaqMan real-time PCR assay for quantitative detection of Pantoea stewartii subsp. stewartii and Stenocarpella maydis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new TaqMan real-time PCR assay was developed for the simultaneous quantitative detection of two seedborne maize pathogens in a single assay. Pantoea stewartii subsp. stewartii (Pnss) (syn. Erwinia stewartii) is the causal agent of Stewart's bacterial wilt and leaf blight of maize. Stewart's wilt i...

  3. Lotus japonicus plants of the Gifu B-129 ecotype subjected to alkaline stress improve their Fe(2+) bio-availability through inoculation with Pantoea eucalypti M91.

    PubMed

    Campestre, María Paula; Castagno, Luis Nazareno; Estrella, María Julia; Ruiz, Oscar Adolfo

    2016-03-15

    Inoculation assays with Pantoea eucalypti M91 were performed on Lotus japonicus ecotype Gifu. Under alkaline conditions, this ecotype is characterized by the development of interveinal chlorosis of the apical leaves due to low mobilization of Fe(2+). Inoculation with P. eucalypti M91, a plant growth-promoting bacterial strain capable of producing pyoverdine-like and pyochelin-like siderophores under alkaline growth conditions, alters the root, resulting in a herringbone pattern of root branching. Additional features include improvement in Fe(2+) transport to the shoots, acidification of the hydroponic solution of the plant cultures, and an accompanying increase in the efficiency of the PSII parameters. In addition, there was an increase in the expression of the FRO1 and IRT1 genes, accompanied by a significant increase in FRO activity. Results showed that P. eucalypti M91 has a beneficial effect on the Fe acquisition machinery of Strategy I, as described for non-graminaceous monocots and dicots, suggesting its potential as an inoculant for legume crops cultivated in alkaline soils.

  4. Denitration of glycerol trinitrate by resting cells and cell extracts of Bacillus thuringiensis/cereus and Enterobacter agglomerans.

    PubMed Central

    Meng, M; Sun, W Q; Geelhaar, L A; Kumar, G; Patel, A R; Payne, G F; Speedie, M K; Stacy, J R

    1995-01-01

    A number of microorganisms were selected from soil and sediment samples which were known to have been previously exposed to nitrate ester contaminants. The two most effective bacteria for transforming glycerol trinitrate (GTN) were identified as Bacillus thuringiensis/cereus and Enterobacter agglomerans. For both isolates, denitration activities were expressed constitutively and GTN was not required for induction. Dialysis of cell extracts from both isolates did not affect denitration, which indicates that dissociable and depletable cofactors are not required for denitration. With thin-layer chromatography and high-performance liquid chromatography, the denitration pathway for both isolates was shown to be a sequential denitration of GTN to glycerol dinitrate isomers, glycerol mononitrate isomers, and ultimately to glycerol. GTN was observed to be completely converted to glycerol during a long-term incubation of cell extracts. PMID:7618866

  5. Denitration of glycerol trinitrate by resting cells and cell extracts of Bacillus thuringiensis/cereus and Enterobacter agglomerans.

    PubMed

    Meng, M; Sun, W Q; Geelhaar, L A; Kumar, G; Patel, A R; Payne, G F; Speedie, M K; Stacy, J R

    1995-07-01

    A number of microorganisms were selected from soil and sediment samples which were known to have been previously exposed to nitrate ester contaminants. The two most effective bacteria for transforming glycerol trinitrate (GTN) were identified as Bacillus thuringiensis/cereus and Enterobacter agglomerans. For both isolates, denitration activities were expressed constitutively and GTN was not required for induction. Dialysis of cell extracts from both isolates did not affect denitration, which indicates that dissociable and depletable cofactors are not required for denitration. With thin-layer chromatography and high-performance liquid chromatography, the denitration pathway for both isolates was shown to be a sequential denitration of GTN to glycerol dinitrate isomers, glycerol mononitrate isomers, and ultimately to glycerol. GTN was observed to be completely converted to glycerol during a long-term incubation of cell extracts.

  6. Improved Detection Sensitivity of a Biological Simulant: Delivery of Chemical Labels to the Cell Surface by Adsorption of Polyethyleneimine Derivatives

    DTIC Science & Technology

    2005-11-01

    5424 Abstract: The use of biological simulants in testing detection/identification instruments often employs antibodies to quantify the amount of...sensitive tests already available. Here we report progress on the development of a method to deliver onto the surface of Eh large numbers of small molecule... tests requiring vegetative bacteria. (It is important to note that the accepted scientific name of the strain used has been changed to Pantoea agglomerans

  7. Isolation of Pantoea ananatis from sugarcane and characterization of its potential for plant growth promotion.

    PubMed

    da Silva, J F; Barbosa, R R; de Souza, A N; da Motta, O V; Teixeira, G N; Carvalho, V S; de Souza, A L S R; de Souza Filho, G A

    2015-11-30

    Each year, approximately 170 million metric tons of chemical fertilizer are consumed by global agriculture. Furthermore, some chemical fertilizers contain toxic by-products and their long-term use may contaminate groundwater, lakes, and rivers. The use of plant growth-promoting bacteria may be a cost-effective strategy for partially replacing conventional chemical fertilizers, and may become an integrated plant nutrient solution for sustainable crop production. The main direct bacteria-activated mechanisms of plant growth promotion are based on improvement of nutrient acquisition, siderophore biosynthesis, nitrogen fixation, and hormonal stimulation. The aim of this study was to isolate and identify bacteria with growth-promoting activities from sugarcane. We extracted the bacterial isolate SCB4789F-1 from sugarcane leaves and characterized it with regard to its profile of growth-promoting activities, including its ability to colonize Arabidopsis thaliana. Based on its biochemical characteristics and 16S rDNA sequence analysis, this isolate was identified as Pantoea ananatis. The bacteria were efficient at phosphate and zinc solubilization, and production of siderophores and indole-3-acetic acid in vitro. The isolate was characterized by Gram staining, resistance to antibiotics, and use of carbon sources. This is the first report on zinc solubilization in vitro by this bacterium, and on plant growth promotion following its inoculation into A. thaliana. The beneficial effects to plants of this bacterium justify future analysis of inoculation of economically relevant crops.

  8. Native halo-tolerant plant growth promoting rhizobacteria Enterococcus and Pantoea sp. improve seed yield of Mungbean (Vigna radiata L.) under soil salinity by reducing sodium uptake and stress injury.

    PubMed

    Panwar, Meenu; Tewari, Rupinder; Nayyar, Harsh

    2016-10-01

    The beneficial microbial-plant interaction plays important role in the soil health, crop growth and productivity. Plant growth promoting rhizobacteria (PGPR) are such beneficial microorganisms, which in association with plant roots not only promote their growth but also help in counteracting the detrimental effects of soil stresses. Salt stress is one such stress, frequently confronted by the plants. The present study aimed at isolation and identification of PGPR inhabiting the mungbean rhizosphere, testing them for salt (NaCl) tolerance and subsequently in salt-supplemented mungbean crop. For this purpose, two salt-tolerant bacterial strains belonging to genus Pantoea and Enterococcus, characterized for their P-solubilization ability, indole acetic acid and siderophore production were selected. These two PGPR were further evaluated for their effect on the salt-stressed mungbean plants, grown at two salt concentrations (5 and 10 dS/m). The plants treated with the combination of PGPR showed better performance in growth (16-37 %) and yield (22-32 %), under salt stress, as compared with control. The increasing salt concentration was found to increase the membrane damage, Na(+) concentration in the plants. PGPR treatments effectively reduced the Na(+) concentration (17-41 %), membrane damage (1.1-1.5 folds) and enhanced the antioxidants i.e. ascorbic acid (8-26 %) and glutathione (10-30 %) in salt-stressed plants, in comparison to uninoculated stressed plants. Overall, the results indicated that both PGPR were effective as stress mitigators however, in combination they showed relatively better improvement in growth, yield as well as oxidative parameters of the salt-affected plants. These findings about the effects of native salt-tolerant PGPR Pantoea and Enterococcus sp. in mungbean crop are novel.

  9. The effects of Pantoea sp.Y4-4 on alfalfa in the remediation of heavy-metal-contaminated soil and auxiliary impacts of plant residues on the remediation of saline alkali soils.

    PubMed

    Li, Shuhuan; Wang, Jie; Gao, Nanxiong; Liu, Lizhu; Chen, Yahua

    2016-11-30

    The plant growth-promoting rhizobacteria (PGPR) Y4-4 was isolated from plant rhizosphere soil and identified as Pantoea sp. by 16S rRNA sequence analysis. The effects of strain Y4-4 on alfalfa grew in heavy metals contaminated soil was investigated using a pot experiment. In Cu rich environment, the dry weight from shoot and total of plant inoculated with strain Y4-4 increased by 22.6% and 21%, and Cu accumulation increased by 15%. In Pb-Zn rich environment, the dry weight from shoot and total of plant inoculated with strain Y4-4 increased by 23.4% and 22%, and Zn accumulation increased by 30.3%. In addition, the salt tolerance and biomass of wheat seedling could be improved by applying strain Y4-4 mixed with plant residue as a result of Cu-rich plant residues provide copper nutrition wheat. This study offers an efficient PGPR with strong salt tolerance and a safe strategy for the post-treatment of plant residue.

  10. The bacterium Pantoea stewartii uses two different type III secretion systems to colonize its plant host and insect vector.

    PubMed

    Correa, Valdir R; Majerczak, Doris R; Ammar, El-Desouky; Merighi, Massimo; Pratt, Richard C; Hogenhout, Saskia A; Coplin, David L; Redinbaugh, Margaret G

    2012-09-01

    Plant- and animal-pathogenic bacteria utilize phylogenetically distinct type III secretion systems (T3SS) that produce needle-like injectisomes or pili for the delivery of effector proteins into host cells. Pantoea stewartii subsp. stewartii (herein referred to as P. stewartii), the causative agent of Stewart's bacterial wilt and leaf blight of maize, carries phylogenetically distinct T3SSs. In addition to an Hrc-Hrp T3SS, known to be essential for maize pathogenesis, P. stewartii has a second T3SS (Pantoea secretion island 2 [PSI-2]) that is required for persistence in its flea beetle vector, Chaetocnema pulicaria (Melsh). PSI-2 belongs to the Inv-Mxi-Spa T3SS family, typically found in animal pathogens. Mutagenesis of the PSI-2 psaN gene, which encodes an ATPase essential for secretion of T3SS effectors by the injectisome, greatly reduces both the persistence of P. stewartii in flea beetle guts and the beetle's ability to transmit P. stewartii to maize. Ectopic expression of the psaN gene complements these phenotypes. In addition, the PSI-2 psaN gene is not required for P. stewartii pathogenesis of maize and is transcriptionally upregulated in insects compared to maize tissues. Thus, the Hrp and PSI-2 T3SSs play different roles in the life cycle of P. stewartii as it alternates between its insect vector and plant host.

  11. The Bacterium Pantoea stewartii Uses Two Different Type III Secretion Systems To Colonize Its Plant Host and Insect Vector

    PubMed Central

    Correa, Valdir R.; Majerczak, Doris R.; Ammar, El-Desouky; Merighi, Massimo; Pratt, Richard C.; Hogenhout, Saskia A.; Coplin, David L.

    2012-01-01

    Plant- and animal-pathogenic bacteria utilize phylogenetically distinct type III secretion systems (T3SS) that produce needle-like injectisomes or pili for the delivery of effector proteins into host cells. Pantoea stewartii subsp. stewartii (herein referred to as P. stewartii), the causative agent of Stewart's bacterial wilt and leaf blight of maize, carries phylogenetically distinct T3SSs. In addition to an Hrc-Hrp T3SS, known to be essential for maize pathogenesis, P. stewartii has a second T3SS (Pantoea secretion island 2 [PSI-2]) that is required for persistence in its flea beetle vector, Chaetocnema pulicaria (Melsh). PSI-2 belongs to the Inv-Mxi-Spa T3SS family, typically found in animal pathogens. Mutagenesis of the PSI-2 psaN gene, which encodes an ATPase essential for secretion of T3SS effectors by the injectisome, greatly reduces both the persistence of P. stewartii in flea beetle guts and the beetle's ability to transmit P. stewartii to maize. Ectopic expression of the psaN gene complements these phenotypes. In addition, the PSI-2 psaN gene is not required for P. stewartii pathogenesis of maize and is transcriptionally upregulated in insects compared to maize tissues. Thus, the Hrp and PSI-2 T3SSs play different roles in the life cycle of P. stewartii as it alternates between its insect vector and plant host. PMID:22773631

  12. A Carotenoid-Deficient Mutant in Pantoea sp. YR343, a Bacteria Isolated from the Rhizosphere of Populus deltoides, Is Defective in Root Colonization

    PubMed Central

    Bible, Amber N.; Fletcher, Sarah J.; Pelletier, Dale A.; Schadt, Christopher W.; Jawdy, Sara S.; Weston, David J.; Engle, Nancy L.; Tschaplinski, Timothy; Masyuko, Rachel; Polisetti, Sneha; Bohn, Paul W.; Coutinho, Teresa A.; Doktycz, Mitchel J.; Morrell-Falvey, Jennifer L.

    2016-01-01

    The complex interactions between plants and their microbiome can have a profound effect on the health and productivity of the plant host. A better understanding of the microbial mechanisms that promote plant health and stress tolerance will enable strategies for improving the productivity of economically important plants. Pantoea sp. YR343 is a motile, rod-shaped bacterium isolated from the roots of Populus deltoides that possesses the ability to solubilize phosphate and produce the phytohormone indole-3-acetic acid (IAA). Pantoea sp. YR343 readily colonizes plant roots and does not appear to be pathogenic when applied to the leaves or roots of selected plant hosts. To better understand the molecular mechanisms involved in plant association and rhizosphere survival by Pantoea sp. YR343, we constructed a mutant in which the crtB gene encoding phytoene synthase was deleted. Phytoene synthase is responsible for converting geranylgeranyl pyrophosphate to phytoene, an important precursor to the production of carotenoids. As predicted, the ΔcrtB mutant is defective in carotenoid production, and shows increased sensitivity to oxidative stress. Moreover, we find that the ΔcrtB mutant is impaired in biofilm formation and production of IAA. Finally we demonstrate that the ΔcrtB mutant shows reduced colonization of plant roots. Taken together, these data suggest that carotenoids are important for plant association and/or rhizosphere survival in Pantoea sp. YR343. PMID:27148182

  13. Draft Genome Sequences of the Onion Center Rot Pathogen Pantoea ananatis PA4 and Maize Brown Stalk Rot Pathogen P. ananatis BD442

    PubMed Central

    Weller-Stuart, Tania; Chan, Wai Yin; Venter, Stephanus N.; Smits, Theo H. M.; Duffy, Brion; Goszczynska, Teresa; Cowan, Don A.; de Maayer, Pieter

    2014-01-01

    Pantoea ananatis is an emerging phytopathogen that infects a broad spectrum of plant hosts. Here, we present the genomes of two South African isolates, P. ananatis PA4, which causes center rot of onion, and BD442, isolated from brown stalk rot of maize. PMID:25103759

  14. A Carotenoid-Deficient Mutant in Pantoea sp. YR343, a Bacteria Isolated from the Rhizosphere of Populus deltoides, Is Defective in Root Colonization

    DOE PAGES

    Bible, Amber; Fletcher, Sarah J; Pelletier, Dale A; ...

    2016-04-18

    The complex interactions between plants and their microbiome can have a profound effect on the health and productivity of the plant host. A better understanding of the microbial mechanisms that promote plant health and stress tolerance will enable strategies for improving the productivity of economically-important plants. Pantoea sp. YR343 is a motile, rod-shaped bacterium isolated from the roots of Populus deltoides that possesses the ability to solubilize phosphate and produce the phytohormone indole-3-acetic acid. Pantoea sp. YR343 readily colonizes plant roots and does not appear to be pathogenic when applied to the leaves or roots of selected plant hosts. Tomore » better understand the molecular mechanisms involved in plant association and rhizosphere survival by Pantoea sp. YR343, we constructed a mutant in which the crtB gene encoding phytoene synthase was deleted. Phytoene synthase is responsible for converting geranylgeranyl pyrophosphate to phytoene, an important precursor to the production of carotenoids. As predicted, the ΔcrtB mutant is defective in carotenoid production, and shows increased sensitivity to oxidative stress. Moreover, we find that the ΔcrtB mutant is impaired in biofilm formation and production of indole-3-acetic acid. Finally we demonstrate that the ΔcrtB mutant shows reduced colonization of plant roots. Taken together, these data suggest that carotenoids are important for plant association and/or rhizosphere survival in Pantoea sp. YR343.« less

  15. A Carotenoid-Deficient Mutant in Pantoea sp. YR343, a Bacteria Isolated from the Rhizosphere of Populus deltoides, Is Defective in Root Colonization

    SciTech Connect

    Bible, Amber; Fletcher, Sarah J; Pelletier, Dale A; Schadt, Christopher Warren; Jawdy, Sara; Weston, David; Engle, Nancy L.; Tschaplinski, Timothy J.; Masyuko, Rachel; Polisetti, Sneha; Bohn, Paul W.; Coutinho, Teresa; Doktycz, Mitchel John; Morrell-Falvey, Jennifer L.

    2016-04-18

    The complex interactions between plants and their microbiome can have a profound effect on the health and productivity of the plant host. A better understanding of the microbial mechanisms that promote plant health and stress tolerance will enable strategies for improving the productivity of economically-important plants. Pantoea sp. YR343 is a motile, rod-shaped bacterium isolated from the roots of Populus deltoides that possesses the ability to solubilize phosphate and produce the phytohormone indole-3-acetic acid. Pantoea sp. YR343 readily colonizes plant roots and does not appear to be pathogenic when applied to the leaves or roots of selected plant hosts. To better understand the molecular mechanisms involved in plant association and rhizosphere survival by Pantoea sp. YR343, we constructed a mutant in which the crtB gene encoding phytoene synthase was deleted. Phytoene synthase is responsible for converting geranylgeranyl pyrophosphate to phytoene, an important precursor to the production of carotenoids. As predicted, the ΔcrtB mutant is defective in carotenoid production, and shows increased sensitivity to oxidative stress. Moreover, we find that the ΔcrtB mutant is impaired in biofilm formation and production of indole-3-acetic acid. Finally we demonstrate that the ΔcrtB mutant shows reduced colonization of plant roots. Taken together, these data suggest that carotenoids are important for plant association and/or rhizosphere survival in Pantoea sp. YR343.

  16. Immunofluorescence localization and ultrastructure of Stewart’s wilt disease bacterium Pantoea stewartii in maize leaves and in its flea beetle vector Chaetocnema pulicaria (Coleoptera: Chrysomelidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pantoea stewartii is the causal agent of Stewart's wilt of sweet corn, the most serious bacterial disease of sweet corn and maize in the North-Central and Eastern USA. P. stewartii is transmitted mainly by the corn flea beetle Chaetocnema pulicaria (Coleoptera: Chrysomelidae) and this bacterium is a...

  17. Rapid isolation of a facultative anaerobic electrochemically active bacterium capable of oxidizing acetate for electrogenesis and azo dyes reduction.

    PubMed

    Shen, Nan; Yuan, Shi-Jie; Wu, Chao; Cheng, Yuan-Yuan; Song, Xiang-Ning; Li, Wen-Wei; Tong, Zhong-Hua; Yu, Han-Qing

    2014-05-01

    In this study, 27 strains of electrochemically active bacteria (EAB) were rapidly isolated and their capabilities of extracellular electron transfer were identified using a photometric method based on WO3 nanoclusters. These strains caused color change of WO3 from white to blue in a 24-well agar plate within 40 h. Most of the isolated EAB strains belonged to the genera of Aeromonas and Shewanella. One isolate, Pantoea agglomerans S5-44, was identified as an EAB that can utilize acetate as the carbon source to produce electricity and reduce azo dyes under anaerobic conditions. The results confirmed the capability of P. agglomerans S5-44 for extracellular electron transfer. The isolation of this acetate-utilizing, facultative EBA reveals the metabolic diversity of environmental bacteria. Such strains have great potential for environmental applications, especially at interfaces of aerobic and anaerobic environments, where acetate is the main available carbon source.

  18. Spatial organization of dual-species bacterial aggregates on leaf surfaces.

    PubMed

    Monier, J-M; Lindow, S E

    2005-09-01

    The spatial organization of cells within bacterial aggregates on leaf surfaces was determined for pair-wise mixtures of three different bacterial species commonly found on leaves, Pseudomonas syringae, Pantoea agglomerans, and Pseudomonas fluorescens. Cells were coinoculated onto bean plants and allowed to grow under moist conditions, and the resulting aggregates were examined in situ by epifluorescence microscopy. Each bacterial strain could be localized because it expressed either the green or the cyan fluorescent protein constitutively, and the viability of individual cells was assessed by propidium iodide staining. Each pair of bacterial strains that was coinoculated onto leaves formed mixed aggregates. The degree of segregation of cells in mixed aggregates differed between the different coinoculated pairs of strains and was higher in mixtures of P. fluorescens A506 and P. agglomerans 299R and mixtures of P. syringae B728a and P. agglomerans 299R than in mixtures of two isogenic strains of P. agglomerans 299R. The fractions of the total cell population that were dead in mixed and monospecific aggregates of a gfp-marked strain of P. agglomerans 299R and a cfp-marked strain of P. agglomerans 299R, or of P. fluorescens A506 and P. agglomerans 299R, were similar. However, the proportion of dead cells in mixed aggregates of P. syringae B728a and P. agglomerans 299R was significantly higher (13.2% +/- 8.2%) than that in monospecific aggregates of these two strains (1.6% +/- 0.7%), and it increased over time. While dead cells in such mixed aggregates were preferentially found at the interface between clusters of cells of these strains, cells of these two strains located at the interface did not exhibit equal probabilities of mortality. After 9 days of incubation, about 77% of the P. agglomerans 299R cells located at the interface were dead, while only about 24% of the P. syringae B728a cells were dead. The relevance of our results to understanding bacterial

  19. Comparative dynamics of adherent and nonadherent bacterial populations on maize leaves.

    PubMed

    Beattie, Gwyn A; Marcell, Lise M

    2002-09-01

    ABSTRACT The dynamics of the adherent and nonadherent populations of three bacterial species on maize leaves were examined to identify the extent to which bacteria adhere to leaves and the importance of this adhesion to leaf colonization. Pantoea agglomerans strain BRT98, Clavibacter michiganensis subsp. nebraskensis strain GH2390, and Pseudomonas syringae pv. syringae strain HS191R all rapidly adhered to maize leaves following inoculation, but differed in the percentage of cells that adhered to the leaves. Immediately following inoculation, the percentage of adherent cells was highest for the saprophyte P. agglomerans (8 to 10%) and was much lower for the pathogens C. michiganensis subsp. nebras-kensis and P. syringae pv. syringae (2 to 3 and <1%, respectively), although the results for P. syringae pv. syringae HS191R were based on only one experiment. In the 4 days following inoculation, the percentage of the P. agglomerans populations that adhered to the leaves increased to approximately 70%. Similarly, the percentage of C. michiganensis subsp. nebraskensis and P. syringae pv. syringae cells that resisted removal steadily increased in the days following inoculation, although these increases probably reflected both adherence and localization to endophytic sites. Based on differences in the percentage of cells adhering to several cuticular wax mutants of maize, the rapid adherence of C. michiganensis subsp. nebraskensis cells to maize leaves was influenced by the cuticular wax properties, while the rapid adherence of P. agglomerans was not. Finally, bacterial adherence to leaves was advantageous to P. agglomerans survival and growth on leaves based on the finding that the nonadherent populations of the P. agglomerans strain decreased significantly more than did the adherent populations in the 24 h following inoculation, and increased much less than did the adherent populations over the next 3 days. Similar results with the C. michiganensis subsp. nebraskensis and

  20. OEM--a new medium for rapid isolation of onion-pathogenic and onion-associated bacteria.

    PubMed

    Zaid, Ali M; Bonasera, Jean M; Beer, Steven V

    2012-12-01

    Onions (Allium cepa L.) are plagued by a number of bacterial pathogens including Pantoea ananatis, P. agglomerans, Burkholderia cepacia, Enterobacter cloacae, Pectobacterium carotovorum subsp. carotovorum, Xanthomonas axonopodis pv. axonopodis and several Pseudomonas spp. We developed a semi-selective medium, termed onion extract medium (OEM), to selectively and rapidly isolate bacteria pathogenic to and associated with onions and onion-related samples including bulbs, seeds, sets, transplant seedlings, soil and water. Most strains of interest grow sufficiently on OEM in 24h at 28°C for tentative identification based on colony morphology, facilitating further characterization by microbiological and/or molecular means.

  1. Perturbation of Maize Phenylpropanoid Metabolism by an AvrE Family Type III Effector from Pantoea stewartii1[OPEN

    PubMed Central

    Asselin, Jo Ann E.; Lin, Jinshan; Perez-Quintero, Alvaro L.; Gentzel, Irene; Majerczak, Doris; Opiyo, Stephen O.; Zhao, Wanying; Paek, Seung-Mann; Kim, Min Gab; Coplin, David L.; Blakeslee, Joshua J.; Mackey, David

    2015-01-01

    AvrE family type III effector proteins share the ability to suppress host defenses, induce disease-associated cell death, and promote bacterial growth. However, despite widespread contributions to numerous bacterial diseases in agriculturally important plants, the mode of action of these effectors remains largely unknown. WtsE is an AvrE family member required for the ability of Pantoea stewartii ssp. stewartii (Pnss) to proliferate efficiently and cause wilt and leaf blight symptoms in maize (Zea mays) plants. Notably, when WtsE is delivered by a heterologous system into the leaf cells of susceptible maize seedlings, it alone produces water-soaked disease symptoms reminiscent of those produced by Pnss. Thus, WtsE is a pathogenicity and virulence factor in maize, and an Escherichia coli heterologous delivery system can be used to study the activity of WtsE in isolation from other factors produced by Pnss. Transcriptional profiling of maize revealed the effects of WtsE, including induction of genes involved in secondary metabolism and suppression of genes involved in photosynthesis. Targeted metabolite quantification revealed that WtsE perturbs maize metabolism, including the induction of coumaroyl tyramine. The ability of mutant WtsE derivatives to elicit transcriptional and metabolic changes in susceptible maize seedlings correlated with their ability to promote disease. Furthermore, chemical inhibitors that block metabolic flux into the phenylpropanoid pathways targeted by WtsE also disrupted the pathogenicity and virulence activity of WtsE. While numerous metabolites produced downstream of the shikimate pathway are known to promote plant defense, our results indicate that misregulated induction of phenylpropanoid metabolism also can be used to promote pathogen virulence. PMID:25635112

  2. Proteomic Analysis of the Quorum-Sensing Regulon in Pantoea stewartii and Identification of Direct Targets of EsaR

    PubMed Central

    Ramachandran, Revathy

    2013-01-01

    The proteobacterium Pantoea stewartii subsp. stewartii causes Stewart's wilt disease in maize when it colonizes the xylem and secretes large amounts of stewartan, an exopolysaccharide. The success of disease pathogenesis lies in the timing of bacterial virulence factor expression through the different stages of infection. Regulation is achieved through a quorum-sensing (QS) system consisting of the acyl-homoserine lactone (AHL) synthase, EsaI, and the transcription regulator EsaR. At low cell densities, EsaR represses transcription of itself and of rcsA, an activator of the stewartan biosynthesis operon; it also activates esaS, which encodes a small RNA (sRNA). Repression or activation ceases at high cell densities when EsaI synthesizes sufficient levels of the AHL ligand N-3-oxo-hexanoyl-l-homoserine lactone to bind and inactivate EsaR. This study aims to identify other genes activated or repressed by EsaR during the QS response. Proteomic analysis identified a QS regulon of more than 30 proteins. Electrophoretic mobility shift assays of promoters of genes encoding differentially expressed proteins distinguished direct targets of EsaR from indirect targets. Additional quantitative reverse transcription-PCR (qRT-PCR) and DNA footprinting analysis established that EsaR directly regulates the promoters of dkgA, glpF, and lrhA. The proteins encoded by dkgA, glpF, and lrhA are a 2,5-diketogluconate reductase, glycerol facilitator, and transcriptional regulator of chemotaxis and motility, respectively, indicating a more global QS response in P. stewartii than previously recognized. PMID:23913428

  3. Detecting cotton boll rot with an electronic nose

    Technology Transfer Automated Retrieval System (TEKTRAN)

    South Carolina Boll Rot is an emerging disease of cotton, Gossypium hirsutum L., caused by the opportunistic bacteria, Pantoea agglomerans (Ewing and Fife). Unlike typical fungal diseases, bolls infected with P. agglomerans continue to appear normal externally, complicating early and rapid detectio...

  4. Erwinia gerundensis sp. nov., a cosmopolitan epiphyte originally isolated from pome fruit trees.

    PubMed

    Rezzonico, Fabio; Smits, Theo H M; Born, Yannick; Blom, Jochen; Frey, Jürg E; Goesmann, Alexander; Cleenwerck, Ilse; de Vos, Paul; Bonaterra, Anna; Duffy, Brion; Montesinos, Emilio

    2016-01-26

    A survey to obtain potential antagonists of pome fruit tree diseases yielded two yellow epiphytic bacterial isolates morphologically similar to Pantoea agglomerans, but showing no biocontrol activity. Whole-Cell MALDI-TOF mass spectrometry and analysis of 16S rRNA and gyrB gene sequences suggested the possibility of a new species with a phylogenetic position in either Pantoea or Erwinia. Multilocus sequence analysis (MLSA) placed the two strains in the genus Erwinia and supported their classification as a novel species. The strains showed general phenotypic characteristics typical of this genus and results of DNA-DNA hybridizations confirmed that they represent a single novel species. Both strains showed a DNA G+C content, as determined by HPLC, of 54.5 mol% and could be discriminated from phylogenetically related species of the genus Erwinia by their ability to utilize potassium gluconate, potassium 2-ketogluconate, D-maltose, D-melibiose and D-raffinose. Whole-genome sequencing of strain EM595T revealed the presence of a chromosomal carotenoid biosynthesis gene cluster similar to those found in Cronobacter and Pantoea spp. that explains the pigmentation of the strain, which is atypical for the genus Erwinia. Additional strains belonging to the same species were recovered from different plant hosts in three different continents, revealing the cosmopolitan nature of this epiphyte. The name Erwinia gerundensis sp. nov. is proposed, with EM595T (= LMG 28990T; = CCOS 903T) as the designated type strain.

  5. Temporal Dynamics of Corn Flea Beetle Populations Infested with Pantoea stewartii, Causal Agent of Stewart's Disease of Corn.

    PubMed

    Esker, P D; Nutter, F W

    2003-02-01

    ABSTRACT In order to better understand the epidemiology of the Stewart's disease of corn pathosystem, quantitative information concerning the temporal dynamics of the amount of pathogen inoculum present in the form of Pantoea stewartii-infested corn flea beetles (Chaetocnema pulicaria) is needed. Temporal changes in the proportion of P. stewartii-infested corn flea beetle populations were monitored by testing individual corn flea beetles for the presence of P. stewartii using a peroxidase-labeled, enzyme-linked immunosorbent assay. Approximately 90 corn flea beetles were collected each week from seven locations in Iowa from September 1998 through October 2000 using sweep nets. The proportion of P. stewartii-infested beetles at the end of the 1998 growing season ranged from 0.04 to 0.19. In spring 1999, the proportion of overwintering adult corn flea beetles infested with P. stewartii ranged from 0.10 to 0.11 and did not differ significantly from the previous fall based on chi(2). During the 1999 corn-growing season, the proportion of infested corn flea beetles ranged from 0.04 to 0.86, with the highest proportions occurring in August. In fall 1999, the proportion of beetles infested with P. stewartii ranged from 0.20 to 0.77. In spring 2000, the proportion of overwintering adult corn flea beetles infested with P. stewartii ranged from 0.08 to 0.30; these proportions were significantly lower than the proportions observed in fall 1999 at Ames, Chariton, and Nashua. During the 2000 corn-growing season, the proportion of P. stewartii-infested corn flea beetles ranged from 0.08 to 0.53, and the highest observed proportions again occurred in August. Corn flea beetle populations sampled in late fall 2000 had proportions of infested beetles ranging from 0.08 to 0.20. This is the first study to quantify the temporal population dynamics of P. stewartii-infested C. pulicaria populations in hybrid corn and provides new quantitative information that should be useful in

  6. Characterization of the Highly Efficient Sucrose Isomerase from Pantoea dispersa UQ68J and Cloning of the Sucrose Isomerase Gene

    PubMed Central

    Wu, Luguang; Birch, Robert G.

    2005-01-01

    Sucrose isomerase (SI) genes from Pantoea dispersa UQ68J, Klebsiella planticola UQ14S, and Erwinia rhapontici WAC2928 were cloned and expressed in Escherichia coli. The predicted products of the UQ14S and WAC2928 genes were similar to known SIs. The UQ68J SI differed substantially, and it showed the highest isomaltulose-producing efficiency in E. coli cells. The purified recombinant WAC2928 SI was unstable, whereas purified UQ68J and UQ14S SIs were very stable. UQ68J SI activity was optimal at pH 5 and 30 to 35°C, and it produced a high ratio of isomaltulose to trehalulose (>22:1) across its pH and temperature ranges for activity (pH 4 to 7 and 20 to 50°C). In contrast, UQ14S SI showed optimal activity at pH 6 and 35°C and produced a lower ratio of isomaltulose to trehalulose (<8:1) across its pH and temperature ranges for activity. UQ68J SI had much higher catalytic efficiency; the Km was 39.9 mM, the Vmax was 638 U mg−1, and the Kcat/Km was 1.79 × 104 M−1 s−1, compared to a Km of 76.0 mM, a Vmax of 423 U mg−1, and a Kcat/Km of 0.62 × 104 M−1 s−1 for UQ14S SI. UQ68J SI also showed no apparent reverse reaction producing glucose, fructose, or trehalulose from isomaltulose. These properties of the P. dispersa UQ68J enzyme are exceptional among purified SIs, and they indicate likely differences in the mechanism at the enzyme active site. They may favor the production of isomaltulose as an inhibitor of competing microbes in high-sucrose environments, and they are likely to be highly beneficial for industrial production of isomaltulose. PMID:15746363

  7. Characterization of the highly efficient sucrose isomerase from Pantoea dispersa UQ68J and cloning of the sucrose isomerase gene.

    PubMed

    Wu, Luguang; Birch, Robert G

    2005-03-01

    Sucrose isomerase (SI) genes from Pantoea dispersa UQ68J, Klebsiella planticola UQ14S, and Erwinia rhapontici WAC2928 were cloned and expressed in Escherichia coli. The predicted products of the UQ14S and WAC2928 genes were similar to known SIs. The UQ68J SI differed substantially, and it showed the highest isomaltulose-producing efficiency in E. coli cells. The purified recombinant WAC2928 SI was unstable, whereas purified UQ68J and UQ14S SIs were very stable. UQ68J SI activity was optimal at pH 5 and 30 to 35 degrees C, and it produced a high ratio of isomaltulose to trehalulose (>22:1) across its pH and temperature ranges for activity (pH 4 to 7 and 20 to 50 degrees C). In contrast, UQ14S SI showed optimal activity at pH 6 and 35 degrees C and produced a lower ratio of isomaltulose to trehalulose (<8:1) across its pH and temperature ranges for activity. UQ68J SI had much higher catalytic efficiency; the Km was 39.9 mM, the Vmax was 638 U mg(-1), and the Kcat/Km was 1.79 x 10(4) M(-1) s(-1), compared to a Km of 76.0 mM, a Vmax of 423 U mg(-1), and a Kcat/Km of 0.62 x 10(4) M(-1) s(-1) for UQ14S SI. UQ68J SI also showed no apparent reverse reaction producing glucose, fructose, or trehalulose from isomaltulose. These properties of the P. dispersa UQ68J enzyme are exceptional among purified SIs, and they indicate likely differences in the mechanism at the enzyme active site. They may favor the production of isomaltulose as an inhibitor of competing microbes in high-sucrose environments, and they are likely to be highly beneficial for industrial production of isomaltulose.

  8. Characterization of plasmids that encode streptomycin-resistance in bacterial epiphytes of apple.

    PubMed

    Huang, T C; Burr, T J

    1999-05-01

    Streptomycin resistance in strains of Pseudomonas syringae pv. papulans, Pantoea agglomerans and a yellow-pigmented, non-fluorescent Pseudomonas sp. (Py), isolated from apple orchards in New York and Washington states, is predominantly associated with strA-strB genes carried on conjugal plasmids (R plasmids). None of 128 resistant Erwinia amylovora strains from the eastern and western USA hybridized with a strA-strB probe, SMP3. Resistant Py strains transfered R plasmids to Ps. syringae pv. papulans and to Py in vitro at frequencies of 10(-1)-10(-2) per recipient cell whereas Ps. syringae pv. papulans transferred its plasmids at frequencies of 10(-2) to below detectable levels. Transfer of R plasmids to P. agglomerans was not detected and resistant P. agglomerans did not transfer their R plasmids to any recipients. R plasmids were found to be highly diverse as measured by DNA fingerprint analysis. Transfer-deficient transposon mutants of R plasmid pCPP519 were generated, and 3.9 kb EcoRI and 3.0 kb SmaI fragments that hybridized with a Tn5 probe were cloned and sequenced. The deduced amino acid sequences of the 3.9 kb fragment were similar to proteins involved in replication, nicking at oriT, and piliation in other bacteria.

  9. Siderophore-Mediated Iron Acquisition Influences Motility and Is Required for Full Virulence of the Xylem-Dwelling Bacterial Phytopathogen Pantoea stewartii subsp. stewartii

    PubMed Central

    Burbank, Lindsey; Mohammadi, Mojtaba

    2014-01-01

    Iron is a key micronutrient for microbial growth but is often present in low concentrations or in biologically unavailable forms. Many microorganisms overcome this challenge by producing siderophores, which are ferric-iron chelating compounds that enable the solubilization and acquisition of iron in a bioactive form. Pantoea stewartii subsp. stewartii, the causal agent of Stewart's wilt of sweet corn, produces a siderophore under iron-limiting conditions. The proteins involved in the biosynthesis and export of this siderophore are encoded by the iucABCD-iutA operon, which is homologous to the aerobactin biosynthetic gene cluster found in a number of enteric pathogens. Mutations in iucA and iutA resulted in a decrease in surface-based motility that P. stewartii utilizes during the early stages of biofilm formation, indicating that active iron acquisition impacts surface motility for P. stewartii. Furthermore, bacterial movement in planta is also dependent on a functional siderophore biosynthesis and uptake pathway. Most notably, siderophore-mediated iron acquisition is required for full virulence in the sweet corn host, indicating that active iron acquisition is essential for pathogenic fitness for this important xylem-dwelling bacterial pathogen. PMID:25326304

  10. Siderophore-mediated iron acquisition influences motility and is required for full virulence of the xylem-dwelling bacterial phytopathogen Pantoea stewartii subsp. stewartii.

    PubMed

    Burbank, Lindsey; Mohammadi, Mojtaba; Roper, M Caroline

    2015-01-01

    Iron is a key micronutrient for microbial growth but is often present in low concentrations or in biologically unavailable forms. Many microorganisms overcome this challenge by producing siderophores, which are ferric-iron chelating compounds that enable the solubilization and acquisition of iron in a bioactive form. Pantoea stewartii subsp. stewartii, the causal agent of Stewart's wilt of sweet corn, produces a siderophore under iron-limiting conditions. The proteins involved in the biosynthesis and export of this siderophore are encoded by the iucABCD-iutA operon, which is homologous to the aerobactin biosynthetic gene cluster found in a number of enteric pathogens. Mutations in iucA and iutA resulted in a decrease in surface-based motility that P. stewartii utilizes during the early stages of biofilm formation, indicating that active iron acquisition impacts surface motility for P. stewartii. Furthermore, bacterial movement in planta is also dependent on a functional siderophore biosynthesis and uptake pathway. Most notably, siderophore-mediated iron acquisition is required for full virulence in the sweet corn host, indicating that active iron acquisition is essential for pathogenic fitness for this important xylem-dwelling bacterial pathogen.

  11. Habitat Visualization and Genomic Analysis of “Candidatus Pantoea carbekii,” the Primary Symbiont of the Brown Marmorated Stink Bug

    PubMed Central

    Kenyon, Laura J.; Meulia, Tea; Sabree, Zakee L.

    2015-01-01

    Phytophagous pentatomid insects can negatively impact agricultural productivity and the brown marmorated stink bug (Halyomorpha halys) is an emerging invasive pest responsible for damage to many fruit crops and ornamental plants in North America. Many phytophagous stink bugs, including H. halys, harbor gammaproteobacterial symbionts that likely contribute to host development, and characterization of symbiont transmission/acquisition and their contribution to host fitness may offer alternative strategies for managing pest species. “Candidatus Pantoea carbekii” is the primary occupant of gastric ceca lumina flanking the distal midgut of H. halys insects and it is acquired each generation when nymphs feed on maternal extrachorion secretions following hatching. Insects prevented from symbiont uptake exhibit developmental delays and aberrant behaviors. To infer contributions of Ca. P. carbekii to H. halys, the complete genome was sequenced and annotated from a North American H. halys population. Overall, the Ca. P. carbekii genome is nearly one-fourth (1.2 Mb) that of free-living congenerics, and retains genes encoding many functions that are potentially host-supportive. Gene content reflects patterns of gene loss/retention typical of intracellular mutualists of plant-feeding insects. Electron and fluorescence in situ microscopic imaging of H. halys egg surfaces revealed that maternal extrachorion secretions were populated with Ca. P. carbekii cells. The reported findings detail a transgenerational mode of symbiont transmission distinct from that observed for intracellular insect mutualists and illustrate the potential additive functions contributed by the bacterial symbiont to this important agricultural pest. PMID:25587021

  12. Quorum sensing in marine snow and its possible influence on production of extracellular hydrolytic enzymes in marine snow bacterium Pantoea ananatis B9.

    PubMed

    Jatt, Abdul Nabi; Tang, Kaihao; Liu, Jiwen; Zhang, Zenghu; Zhang, Xiao-Hua

    2015-02-01

    Marine snow is a continuous shower of organic and inorganic detritus, and plays a crucial role in transporting materials from the sea surface to the deep ocean. The aims of the current study were to identify N-acyl homoserine lactone (AHL)-based quorum sensing (QS) signaling molecules directly from marine snow particles and to investigate the possible regulatory link between QS signals and extracellular hydrolytic enzymes produced by marine snow bacteria. The marine snow samples were collected from the surface water of China marginal seas. Two AHLs, i.e. 3OC6-HSL and C8-HSL, were identified directly from marine snow particles, while six different AHL signals, i.e. C4-HSL, 3OC6-HSL, C6-HSL, C10-HSL, C12-HSL and C14-HSL were produced by Pantoea ananatis B9 inhabiting natural marine snow particles. Of the extracellular hydrolytic enzymes produced by P. ananatis B9, alkaline phosphatase activity was highly enhanced in growth medium supplemented with exogenous AHL (C10-HSL), while quorum quenching enzyme (AiiA) drastically reduced the enzyme activity. To our knowledge, this is the first report revealing six different AHL signals produced by P. ananatis B9 and AHL-based QS system enhanced the extracellular hydrolytic enzyme in P. ananatis B9. Furthermore, this study first time revealing 3OC6-HSL production by Paracoccus carotinifaciens affiliated with Alphaproteobacteria.

  13. 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.

  14. Bacteria Classification via Surface Enhanced Raman Spectroscopy and Principal Component Analysis

    DTIC Science & Technology

    2006-11-01

    tularaemia and Brucella neotomae is a subtype species of Brucella melitensis which is a food pathogen that can affect cattle and bison but is non...agglomerans,and Brucella noetomae. 1. Introduction The need for faster, more reliable biological detection systems is greater now then ever before...suspensions were stored at 4°C until needed. Washed vegetative cells of Pantoea agglomerans (Formally known as Erwinia herbicola-ATCC 13329), Brucella

  15. Evaluation of plant growth promoting and colonization ability of endophytic diazotrophs from deep water rice.

    PubMed

    Verma, S C; Ladha, J K; Tripathi, A K

    2001-10-04

    A study of the diversity of endophytic bacteria present in seeds of a deepwater rice variety revealed the presence of seven types of BOX-PCR fingerprints. In order to evaluate the plant growth promoting potential the presence of nitrogenase, indole acetic acid production and mineral phosphate solubilization were estimated in the representative BOX-PCR types. The seven representatives of BOX-PCR types produced indole acetic acid, reduced acetylene and showed specific immunological cross-reaction with anti-dinitrogenase reductase antibody. Only four types showed mineral phosphate solubilizing ability. Comparison of cellulase and pectinase activities showed differences among different BOX-PCR types. PCR fingerprinting data showed that one strain isolated from the surface sterilized seeds as well as the aerial parts of the seedlings of rice variety showed low cellulase and pectinase but relatively high ARA. On the basis of 16S rDNA nucleotide sequence and BIOLOG system of bacterial identification, this strain was identified as Pantoea agglomerans. For studying the endophytic colonization this strain was genetically tagged with the reporter gene, gusA. Histochemical analysis of the seedling grown in hydroponics showed that the tagged strain colonized the root surface, root hairs, root cap, points of lateral root emergence, root cortex and the stelar region. Treatment of the roots with 2,4-D produced short thickened lateral roots which showed better colonization by P. agglomerans.

  16. 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.

  17. Diversity of fecal coliforms and their antimicrobial resistance patterns in wastewater treatment model plant.

    PubMed

    Luczkiewicz, A; Fudala-Ksiazek, S; Jankowska, K; Quant, B; Olańczuk-Neyman, K

    2010-01-01

    The occurrence of resistance patterns among wastewater fecal coliforms was determined in the study. Susceptibility of the isolates was tested against 19 antimicrobial agents: aminoglycosides, aztreonam, carbapenems, cephalosporines, beta-lactam/beta-lactamase inhibitors, penicillines, tetracycline, trimethoprim/sulfamethoxazole, and fluoroquinolones. Additionally the removal of resistant isolates was evaluated in the laboratory-scale wastewater treatment model plant (M-WWTP), continuously supplied with the wastewater obtained from the full-scale WWTP. Number of fecal coliforms in raw (after mechanical treatment) and treated wastewater, as well as in aerobic chamber effluent was determined using selective medium. The selected strains were identified and examined for antibiotic resistance using Phoenix Automated Microbiology System (BD Biosciences, USA). The strains were identified as Escherichia coli (n=222), Klebsiella pneumoniae ssp. ozaenae (n=9), and Pantoea agglomerans (n=1). The isolate of P. agglomerans as well as 48% of E. coli isolates were sensitive to all antimicrobials tested. The most frequent resistance patterns were found for ampicillin: 100% of K. pneumoniae ssp. ozaenae and 41% of E. coli isolates. Among E. coli isolates 12% was regarded as multiple antimicrobial resistant (MAR). In the studied M-WWTP, the applied activated sludge processes reduced considerably the number of fecal coliforms, but increased the ratio of antimicrobial-resistant E. coli isolates to sensitive ones, especially among strains with MAR patterns.

  18. Molecular Characterization of Pantoea stewartii subsp. stewartii HrpY, a Conserved Response Regulator of the Hrp Type III Secretion System, and its Interaction with the hrpS Promoter†

    PubMed Central

    Merighi, Massimo; Majerczak, Doris R.; Zianni, Michael; Tessanne, Kimberly; Coplin, David L.

    2006-01-01

    Pantoea stewartii subsp. stewartii is a bacterial pathogen of corn. Its pathogenicity depends on the translocation of effector proteins into host cells by the Hrp type III secretion system. We previously showed by genetic analysis that the HrpX sensor kinase and the HrpY response regulator are at the head of a complex cascade of regulators controlling hrp/hrc secretion and wts effector genes. This cascade also includes the HrpS response regulator and the HrpL alternative sigma factor. These regulators are shared among many important plant pathogens in the genera Pantoea, Erwinia, and Pseudomonas. In this study, we dissect the regulatory elements in the hrpS promoter region, using genetic and biochemical approaches, and show how it integrates various environmental signals, only some of which are dependent on phosphorylation of HrpY. Primer extension located the transcriptional start site of hrpS at a σ70 promoter 601 bp upstream of the open reading frame. Electrophoretic mobility shift assays and DNase I footprinting analysis demonstrated that HrpY binds to conserved regulatory elements immediately adjacent to this promoter, and its binding affinity was increased by phosphorylation at D57. A consensus sequence for the two direct repeats bound by HrpY is proposed. Deletion analysis of the promoter region revealed that both the HrpY binding site and additional sequences farther upstream, including a putative integration host factor binding site, are required for hrpS expression. This finding suggests that other unknown regulatory proteins may act cooperatively with HrpY. PMID:16816181

  19. Mechanistically compatible mixtures of bacterial antagonists improve biological control of fire blight of pear.

    PubMed

    Stockwell, V O; Johnson, K B; Sugar, D; Loper, J E

    2011-01-01

    Mixtures of biological control agents can be superior to individual agents in suppressing plant disease, providing enhanced efficacy and reliability from field to field relative to single biocontrol strains. Nonetheless, the efficacy of combinations of Pseudomonas fluorescens A506, a commercial biological control agent for fire blight of pear, and Pantoea vagans strain C9-1 or Pantoea agglomerans strain Eh252 rarely exceeds that of individual strains. A506 suppresses growth of the pathogen on floral colonization and infection sites through preemptive exclusion. C9-1 and Eh252 produce peptide antibiotics that contribute to disease control. In culture, A506 produces an extracellular protease that degrades the peptide antibiotics of C9-1 and Eh252. We hypothesized that strain A506 diminishes the biological control activity of C9-1 and Eh252, thereby reducing the efficacy of biocontrol mixtures. This hypothesis was tested in five replicated field trials comparing biological control of fire blight using strain A506 and A506 aprX::Tn5, an extracellular protease-deficient mutant, as individuals and combined with C9-1 or Eh252. On average, mixtures containing A506 aprX::Tn5 were superior to those containing the wild-type strain, confirming that the extracellular protease of A506 diminished the biological control activity of C9-1 and Eh252 in situ. Mixtures of A506 aprX::Tn5 and C9-1 or Eh252 were superior to oxytetracycline or single biocontrol strains in suppressing fire blight of pear. These experiments demonstrate that certain biological control agents are mechanistically incompatible, in that one strain interferes with the mechanism by which a second strain suppresses plant disease. Mixtures composed of mechanistically compatible strains of biological control agents can suppress disease more effectively than individual biological control agents.

  20. Soil type affects plant colonization, activity and catabolic gene expression of inoculated bacterial strains during phytoremediation of diesel.

    PubMed

    Afzal, Muhammad; Yousaf, Sohail; Reichenauer, Thomas G; Kuffner, Melanie; Sessitsch, Angela

    2011-02-28

    The combined use of plants and associated microorganisms has great potential for cleaning up soils contaminated with petroleum hydrocarbons. Apart from environmental conditions the physicochemical properties of the soil are the main factors influencing the survival and activity of an inoculated strain as well as the growth of plants. This study examined the effect of different soil types (sandy, loamy sand and loam) on the survival, gene abundance and catabolic gene expression of two inoculated strains (Pseudomonas sp. strain ITRI53 and Pantoea sp. strain BTRH79) in the rhizosphere and shoot interior of Italian ryegrass vegetated in diesel contaminated soils. High colonization, gene abundance and expression in loamy soils were observed. By contrast, low colonization, gene abundance and absence of gene expression in sandy soil were found. The highest levels of genes expression and hydrocarbon degradation were seen in loamy soil that had been inoculated with BTRH79 and were significantly higher compared to those in other soils. A positive correlation was observed between gene expression and hydrocarbon degradation indicating that catabolic gene expression is necessary for contaminant degradation. These results suggest that soil type influences the bacterial colonization and microbial activities and subsequently the efficiency of contaminant degradation.

  1. Fighting malaria with engineered symbiotic bacteria from vector mosquitoes.

    PubMed

    Wang, Sibao; Ghosh, Anil K; Bongio, Nicholas; Stebbings, Kevin A; Lampe, David J; Jacobs-Lorena, Marcelo

    2012-07-31

    The most vulnerable stages of Plasmodium development occur in the lumen of the mosquito midgut, a compartment shared with symbiotic bacteria. Here, we describe a strategy that uses symbiotic bacteria to deliver antimalaria effector molecules to the midgut lumen, thus rendering host mosquitoes refractory to malaria infection. The Escherichia coli hemolysin A secretion system was used to promote the secretion of a variety of anti-Plasmodium effector proteins by Pantoea agglomerans, a common mosquito symbiotic bacterium. These engineered P. agglomerans strains inhibited development of the human malaria parasite Plasmodium falciparum and rodent malaria parasite Plasmodium berghei by up to 98%. Significantly, the proportion of mosquitoes carrying parasites (prevalence) decreased by up to 84% for two of the effector molecules, scorpine, a potent antiplasmodial peptide and (EPIP)(4), four copies of Plasmodium enolase-plasminogen interaction peptide that prevents plasminogen binding to the ookinete surface. We demonstrate the use of an engineered symbiotic bacterium to interfere with the development of P. falciparum in the mosquito. These findings provide the foundation for the use of genetically modified symbiotic bacteria as a powerful tool to combat malaria.

  2. Fitness of Salmonella enterica serovar Thompson in the cilantro phyllosphere.

    PubMed

    Brandl, Maria T; Mandrell, Robert E

    2002-07-01

    The epiphytic fitness of Salmonella enterica was assessed on cilantro plants by using a strain of S. enterica serovar Thompson that was linked to an outbreak resulting from cilantro. Salmonella serovar Thompson had the ability to colonize the surface of cilantro leaves, where it was detected by confocal laser scanning microscopy (CLSM) at high densities on the veins and in natural lesions. The population sizes of two common colonizers of plant surfaces, Pantoea agglomerans and Pseudomonas chlororaphis, were 10-fold higher than that of the human pathogen on cilantro incubated at 22 degrees C. However, Salmonella serovar Thompson achieved significantly higher population levels and accounted for a higher proportion of the total culturable bacterial flora on cilantro leaves when the plants were incubated at warm temperatures, such as 30 degrees C, after inoculation, indicating that the higher growth rates exhibited by Salmonella serovar Thompson at warm temperatures may increase the competitiveness of this organism in the phyllosphere. The tolerance of Salmonella serovar Thompson to dry conditions on plants at 60% relative humidity was at least equal to that of P. agglomerans and P. chlororaphis. Moreover, after exposure to low humidity on cilantro, Salmonella serovar Thompson recovered under high humidity to achieve its maximum population size in the cilantro phyllosphere. Visualization by CLSM of green fluorescent protein-tagged Salmonella serovar Thompson and dsRed-tagged P. agglomerans inoculated onto cilantro revealed that the human pathogen and the bacterial epiphyte formed large heterogeneous aggregates on the leaf surface. Our studies support the hypothesis that preharvest contamination of crops by S. enterica plays a role in outbreaks linked to fresh fruits and vegetables.

  3. 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.

  4. 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.

  5. 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 ( ...

  6. 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 ...

  7. Chemical composition of essential oil from ripe fruit of Schinus terebinthifolius Raddi and evaluation of its activity against wild strains of hospital origin.

    PubMed

    Cole, E R; dos Santos, R B; Lacerda Júnior, V; Martins, J D L; Greco, S J; Cunha Neto, A

    2014-01-01

    The essential oil (EO) composition of ripe fruit of S. terebinthifolius Raddi was analyzed by GC-MS. The oil extraction yielded 6.54 ± 1.06% (w/w). Seventeen compounds were identified, accounting for 91.15% of the total oil, where monoterpenes constituted the main chemical class (85.81%), followed by sesquiterpenes (5.34%). The major monoterpene identified was δ-3-carene (30.37%), followed by limonene (17.44%), α-phellandrene (12.60%) and α-pinene (12.59%). Trans-caryophyllene (1.77%) was the major sesquiterpene identified. The antibacterial activity of the essential oil was evaluated against wild strains of hospital origin (Escherichia coli, Pseudomonas sp., Klebsiella oxytoca, Corynebacterium sp., Staphylococcus aureus, Enterobacter sp., Enterobacter agglomerans, Bacillus sp., Nocardia sp. and Streptococcus group D). The essential oil of the ripe fruit of S. terebinthifolius Raddi has shown to be active against all tested wild strains, with minimum inhibitory concentration ranging from 3.55 μg/mL to 56.86 μg/mL. However, it has revealed some differences in susceptibility: the general, Gram-positive species showed greater sensitivity to the action of EO, which is probably due to the lower structural complexity of their cell walls.

  8. Chemical composition of essential oil from ripe fruit of Schinus terebinthifolius Raddi and evaluation of its activity against wild strains of hospital origin

    PubMed Central

    Cole, E.R.; dos Santos, R.B.; Júnior, V. Lacerda; Martins, J.D.L.; Greco, S.J.; Neto, A. Cunha

    2014-01-01

    The essential oil (EO) composition of ripe fruit of S. terebinthifolius Raddi was analyzed by GC-MS. The oil extraction yielded 6.54 ± 1.06% (w/w). Seventeen compounds were identified, accounting for 91.15% of the total oil, where monoterpenes constituted the main chemical class (85.81%), followed by sesquiterpenes (5.34%). The major monoterpene identified was δ-3-carene (30.37%), followed by limonene (17.44%), α-phellandrene (12.60%) and α-pinene (12.59%). Trans-caryophyllene (1.77%) was the major sesquiterpene identified. The antibacterial activity of the essential oil was evaluated against wild strains of hospital origin (Escherichia coli, Pseudomonas sp., Klebsiella oxytoca, Corynebacterium sp., Staphylococcus aureus, Enterobacter sp., Enterobacter agglomerans, Bacillus sp., Nocardia sp. and Streptococcus group D). The essential oil of the ripe fruit of S. terebinthifolius Raddi has shown to be active against all tested wild strains, with minimum inhibitory concentration ranging from 3.55 μg/mL to 56.86 μg/mL. However, it has revealed some differences in susceptibility: the general, Gram-positive species showed greater sensitivity to the action of EO, which is probably due to the lower structural complexity of their cell walls. PMID:25477913

  9. Microbial communities of printing paper machines.

    PubMed

    Väisänen, O M; Weber, A; Bennasar, A; Rainey, F A; Busse, H J; Salkinoja-Salonen, M S

    1998-06-01

    The microbial content of printing paper machines, running at a temperature of 45-50 degrees C and at pH 4.5-5, was studied. Bacteria were prevalent colonizers of the machine wet end and the raw materials. A total of 390 strains of aerobic bacteria were isolated and 86% of these were identified to genus and species by biochemical, chemotaxonomic and phylogenetic methods. The most common bacteria found at the machine wet end were Bacillus coagulans and other Bacillus species, Burkholderia cepacia, Ralstonia pickettii, and in pink slimes, accumulating in the wire area and press section, species of Deinococcus, aureobacterium and Brevibacterium. Paper-making chemicals also contained species of Aureobacterium, B. cereus, B. licheniformis, B. sphaericus, Bordetella, Hydrogenophaga, Klebsiella pneumoniae, Pantoea agglomerans, Pseudomonas stutzeri, Staphylococcus and sometimes other enteric bacteria, but these did not colonize the process water. Yeasts and moulds were not present in significant numbers. A total of 131 strains were tested for their potential to degrade paper-making raw materials; 91 strains were found to have degradative activity, mainly species of Burkholderia and Ralstonia, Sphingomonas and Bacillus, and enterobacteria produced enzymes which degraded paper-making chemicals. Stainless steel adhering strains occurred in slimes and wire water and were identified as Burkholderia cepacia, B. coagulans and Deinococcus geothermalis. Coloured slimes were formed on the machine by species of Deinococcus, Acinetobacter and Methylobacterium (pink), Aureobacterium, Pantoea and Ralstonia (yellowish) and Microbulbifer-related strains (brown). The impact of the strains and species found in the printing paper machine community on the technical quality of paper, machine operation, and as a potential biohazard (Hazard Group 2 bacteria), is discussed.

  10. 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.

  11. 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.

  12. 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.

  13. 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 ...

  14. Engineering of a plasmid-free Escherichia coli strain for improved in vivo biosynthesis of astaxanthin

    PubMed Central

    2011-01-01

    Background The xanthophyll astaxanthin is a high-value compound with applications in the nutraceutical, cosmetic, food, and animal feed industries. Besides chemical synthesis and extraction from naturally producing organisms like Haematococcus pluvialis, heterologous biosynthesis in non-carotenogenic microorganisms like Escherichia coli, is a promising alternative for sustainable production of natural astaxanthin. Recent achievements in the metabolic engineering of E. coli strains have led to a significant increase in the productivity of carotenoids like lycopene or β-carotene by increasing the metabolic flux towards the isoprenoid precursors. For the heterologous biosynthesis of astaxanthin in E. coli, however, the conversion of β-carotene to astaxanthin is obviously the most critical step towards an efficient biosynthesis of astaxanthin. Results Here we report the construction of the first plasmid-free E. coli strain that produces astaxanthin as the sole carotenoid compound with a yield of 1.4 mg/g cdw (E. coli BW-ASTA). This engineered E. coli strain harbors xanthophyll biosynthetic genes from Pantoea ananatis and Nostoc punctiforme as individual expression cassettes on the chromosome and is based on a β-carotene-producing strain (E. coli BW-CARO) recently developed in our lab. E. coli BW-CARO has an enhanced biosynthesis of the isoprenoid precursor isopentenyl diphosphate (IPP) and produces β-carotene in a concentration of 6.2 mg/g cdw. The expression of crtEBIY along with the β-carotene-ketolase gene crtW148 (NpF4798) and the β-carotene-hydroxylase gene (crtZ) under controlled expression conditions in E. coli BW-ASTA directed the pathway exclusively towards the desired product astaxanthin (1.4 mg/g cdw). Conclusions By using the λ-Red recombineering technique, genes encoding for the astaxanthin biosynthesis pathway were stably integrated into the chromosome of E. coli. The expression levels of chromosomal integrated recombinant biosynthetic genes were

  15. 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.

  16. Plant growth promoting capability and genetic diversity of bacteria isolated from mud volcano and lime cave of Andaman and Nicobar Islands.

    PubMed

    Venkadesaperumal, Gopu; Amaresan, Natrajan; Kumar, Krishna

    2014-01-01

    Twenty four bacterial strains from four different regions of mud volcano and lime cave were isolated to estimate their diversity, plant growth promoting and biocontrol activities to use them as inoculant strains in the fields. An excellent antagonistic effect against four plant pathogens and plant growth promoting properties such as IAA production, HCN production, phosphate solubilization, siderophore production, starch hydrolysis and hydrolytic enzymes syntheses were identified in OM5 (Pantoea agglomerans) and EM9 (Exiguobacterium sp.) of 24 studied isolates. Seeds (Chili and tomato) inoculation with plant growth promoting strains resulted in increased percentage of seedling emergence, root length and plant weight. Results indicated that co-inoculation gave a more pronounced effects on seedling emergence, secondary root numbers, primary root length and stem length, while inoculation by alone isolate showed a lower effect. Our results suggest that the mixed inocula of OM5 and EM9 strains as biofertilizers could significantly increase the production of food crops in Andaman archipelago by means of sustainable and organic agricultural system.

  17. Plant growth promoting capability and genetic diversity of bacteria isolated from mud volcano and lime cave of Andaman and Nicobar Islands

    PubMed Central

    Venkadesaperumal, Gopu; Amaresan, Natrajan; Kumar, Krishna

    2014-01-01

    Twenty four bacterial strains from four different regions of mud volcano and lime cave were isolated to estimate their diversity, plant growth promoting and biocontrol activities to use them as inoculant strains in the fields. An excellent antagonistic effect against four plant pathogens and plant growth promoting properties such as IAA production, HCN production, phosphate solubilization, siderophore production, starch hydrolysis and hydrolytic enzymes syntheses were identified in OM5 (Pantoea agglomerans) and EM9 (Exiguobacterium sp.) of 24 studied isolates. Seeds (Chili and tomato) inoculation with plant growth promoting strains resulted in increased percentage of seedling emergence, root length and plant weight. Results indicated that co-inoculation gave a more pronounced effects on seedling emergence, secondary root numbers, primary root length and stem length, while inoculation by alone isolate showed a lower effect. Our results suggest that the mixed inocula of OM5 and EM9 strains as biofertilizers could significantly increase the production of food crops in Andaman archipelago by means of sustainable and organic agricultural system. PMID:25763031

  18. 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.

  19. 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.

  20. 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.

  1. Diversity and Antimicrobial Properties of Lactic Acid Bacteria Isolated from Rhizosphere of Olive Trees and Desert Truffles of Tunisia

    PubMed Central

    Najjari, Afef; Turki, Yousra; Jaballah, Sana; Boudabous, Abdelatif; Ouzari, Hadda

    2013-01-01

    A total of 119 lactic acid bacteria (LAB) were isolated, by culture-dependant method, from rhizosphere samples of olive trees and desert truffles and evaluated for different biotechnological properties. Using the variability of the intergenic spacer 16S-23S and 16S rRNA gene sequences, the isolates were identified as the genera Lactococcus, Pediococcus, Lactobacillus, Weissella, and Enterococcus. All the strains showed proteolytic activity with variable rates 42% were EPS producers, while only 10% showed the ability to grow in 9% NaCl. In addition, a low rate of antibiotic resistance was detected among rhizospheric enterococci. Furthermore, a strong antibacterial activity against plant and/or pathogenic bacteria of Stenotrophomonas maltophilia, Pantoea agglomerans, Pseudomonas savastanoi, the food-borne Staphylococcus aureus, and Listeria monocytogenes was recorded. Antifungal activity evaluation showed that Botrytis cinerea was the most inhibited fungus followed by Penicillium expansum, Verticillium dahliae, and Aspergillus niger. Most of the active strains belonged to the genera Enterococcus and Weissella. This study led to suggest that environmental-derived LAB strains could be selected for technological application to control pathogenic bacteria and to protect food safety from postharvest deleterious microbiota. PMID:24151598

  2. Temperature and Pomaceous Flower Age Related to Colonization by Erwinia amylovora and Antagonists.

    PubMed

    Pusey, P L; Curry, E A

    2004-08-01

    ABSTRACT Fire blight of apple and pear is initiated by epiphytic populations of Erwinia amylovora on flower stigmas. Predicting this disease and managing it with microbial antagonists depends on an understanding of bacterial colonization on stigmas. Detached 'Manchurian' crab apple flowers were inoculated with E. amylovora and subjected to a range of constant temperatures or various fluctuating temperature regimes. Results may have application to disease risk assessment systems such as the Cougarblight model, which now are based on in vitro growth of the pathogen. In other experiments, detached crab apple flowers and attached 'Gala' apple flowers were maintained at different temperatures for various periods before inoculation with E. amylovora or antagonists (Pseudomonas fluorescens strain A506 and Pantoea agglomerans strains C9-1 and E325). Maximum stigma age supporting bacterial multiplication decreased as temperature increased, and was reduced by pollination. Stigmas were receptive to bacteria at ages older than previously reported, probably due to less interference from indigenous organisms. The study revealed antagonist limitations that possibly affect field performance (e.g., the inability of strain A506 to grow on relatively old stigmas conducive to the pathogen). Such deficiencies could be overcome by selecting other antagonists or using antagonist mixtures in the orchard.

  3. 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.

  4. 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.

  5. 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.

  6. Structure of the d-alanylgriseoluteic acid biosynthetic protein EhpF, an atypical member of the ANL superfamily of adenylating enzymes

    SciTech Connect

    Bera, Asim K.; Atanasova, Vesna; Gamage, Swarna; Robinson, Howard; Parsons, James F.

    2010-06-01

    The structure of EhpF from P. agglomerans has been solved alone and in complex with phenazine-1,6-dicarboxylate. Apo EhpF was solved and refined in two different space groups at 1.95 and 2.3 Å resolution and the EhpF–phenazine-1,6-dicarboxylate complex structure was determined at 2.8 Å resolution. The structure of EhpF, a 41 kDa protein that functions in the biosynthetic pathway leading to the broad-spectrum antimicrobial compound d-alanylgriseoluteic acid (AGA), is reported. A cluster of approximately 16 genes, including ehpF, located on a 200 kbp plasmid native to certain strains of Pantoea agglomerans encodes the proteins that are required for the conversion of chorismic acid to AGA. Phenazine-1,6-dicarboxylate has been identified as an intermediate in AGA biosynthesis and deletion of ehpF results in accumulation of this compound in vivo. The crystallographic data presented here reveal that EhpF is an atypical member of the acyl-CoA synthase or ANL superfamily of adenylating enzymes. These enzymes typically catalyze two-step reactions involving adenylation of a carboxylate substrate followed by transfer of the substrate from AMP to coenzyme A or another phosphopantetheine. EhpF is distinguished by the absence of the C-terminal domain that is characteristic of enzymes from this family and is involved in phosphopantetheine binding and in the second half of the canonical two-step reaction that is typically observed. Based on the structure of EhpF and a bioinformatic analysis, it is proposed that EhpF and EhpG convert phenazine-1,6-dicarboxylate to 6-formylphenazine-1-carboxylate via an adenylyl intermediate.

  7. Characterization of ACC deaminase-producing endophytic bacteria isolated from copper-tolerant plants and their potential in promoting the growth and copper accumulation of Brassica napus.

    PubMed

    Zhang, Yan-Feng; He, Lin-Yan; Chen, Zhao-Jin; Wang, Qing-Ya; Qian, Meng; Sheng, Xia-Fang

    2011-03-01

    One hundred Cu-resistant-endophytic bacteria were isolated from Cu-tolerant plants grown on Cu mine wasteland, of which, eight Cu-resistant and 1-aminocyclopropane-1-carboxylate (ACC) deaminase-producing endophytic bacteria were obtained based on the ACC deaminase activity of the bacteria and characterized with respect to metal resistance, production of ACC deaminase, indole-3-acetic acid (IAA) as well as siderophores and mineral phosphate solubilization. Ralstonia sp. J1-22-2, Pantoea agglomerans Jp3-3, and Pseudomonas thivervalensis Y1-3-9 with higher ACC deaminase activity (ranging from 213 to 370 μM α-ketobutyrate mg(-1)h(-1)) were evaluated for promoting plant growth and Cu uptake of rape grown in quartz sand containing 0, 2.5, and 5 mg kg(-1) of Cu in pot experiments. The eight bacteria were found to exhibit different multiple heavy metal resistance characteristics, to show different levels of ACC deaminase activity and to produce indole acetic acid. Seven bacteria produced siderophores and solubilized inorganic phosphate. Pot experiments showed that inoculation with the strains (J1-22-2, Jp3-3, and Y1-3-9) was found to increase the biomass of rape. Increases in above-ground tissue Cu contents of rape cultivated in 2.5 and 5 mg kg(-1) of Cu-contaminated substrates varied from 9% to 31% and from 3 to 4-fold respectively in inoculated-rape plants compared to the uninoculated control. The maximum Cu uptake of rape was observed after inoculation with P. agglomerans Jp3-3. The results show that metal-resistant and plant growth promoting endophytic bacteria play an important role in plant growth and Cu uptake which may provide a new endophytic bacterial-assisted phytoremediation of Cu-contaminated environment.

  8. 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.

  9. Sprains and Strains

    MedlinePlus

    ... Typically, people with a strain experience pain, limited motion, muscle spasms, and possibly muscle weakness. They also ... program designed to prevent stiffness, improve range of motion, and restore the joint's normal flexibility and strength. ...

  10. 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 ...

  11. 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.

  12. Isolation of Bacteria with Antifungal Activity against the Phytopathogenic Fungi Stenocarpella maydis and Stenocarpella macrospora

    PubMed Central

    Petatán-Sagahón, Iván; Anducho-Reyes, Miguel Angel; Silva-Rojas, Hilda Victoria; Arana-Cuenca, Ainhoa; Tellez-Jurado, Alejandro; Cárdenas-Álvarez, Isabel Oyuki; Mercado-Flores, Yuridia

    2011-01-01

    Stenocarpella maydis and Stenocarpella macrospora are the causal agents of ear rot in corn, which is one of the most destructive diseases in this crop worldwide. These fungi are important mycotoxin producers that cause different pathologies in farmed animals and represent an important risk for humans. In this work, 160 strains were isolated from soil of corn crops of which 10 showed antifungal activity against these phytopathogens, which, were identified as: Bacillus subtilis, Pseudomonas spp., Pseudomonas fluorescens, and Pantoea agglomerans by sequencing of 16S rRNA gene and the phylogenetic analysis. From cultures of each strain, extracellular filtrates were obtained and assayed to determine antifungal activity. The best filtrates were obtained in the stationary phase of B. subtilis cultures that were stable to the temperature and extreme pH values; in addition they did not show a cytotoxicity effect against brine shrimp and inhibited germination of conidia. The bacteria described in this work have the potential to be used in the control of white ear rot disease. PMID:22016606

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. Hamstring strain - aftercare

    MedlinePlus

    ... not to push yourself too hard or too fast. A hamstring strain can recur, or your hamstring may tear. Talk to your provider before returning to work or any physical activity. Returning to normal activity too early can cause re-injury.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. Structure of the D-alanylgriseoluteic acid biosynthetic protein EhpF, an atypical member of the ANL superfamily of adenylating enzymes

    SciTech Connect

    Bera, A.K.; Robinson, H.; Atanasova, V.; Gamage, S.; Parsons, J. F.

    2010-06-01

    The structure of EhpF, a 41 kDa protein that functions in the biosynthetic pathway leading to the broad-spectrum antimicrobial compound D-alanylgriseoluteic acid (AGA), is reported. A cluster of approximately 16 genes, including ehpF, located on a 200 kbp plasmid native to certain strains of Pantoea agglomerans encodes the proteins that are required for the conversion of chorismic acid to AGA. Phenazine-1,6-dicarboxylate has been identified as an intermediate in AGA biosynthesis and deletion of ehpF results in accumulation of this compound in vivo. The crystallographic data presented here reveal that EhpF is an atypical member of the acyl-CoA synthase or ANL superfamily of adenylating enzymes. These enzymes typically catalyze two-step reactions involving adenylation of a carboxylate substrate followed by transfer of the substrate from AMP to coenzyme A or another phosphopantetheine. EhpF is distinguished by the absence of the C-terminal domain that is characteristic of enzymes from this family and is involved in phosphopantetheine binding and in the second half of the canonical two-step reaction that is typically observed. Based on the structure of EhpF and a bioinformatic analysis, it is proposed that EhpF and EhpG convert phenazine-1,6-dicarboxylate to 6-formylphenazine-1-carboxylate via an adenylyl intermediate.

  6. Protective role of biogenic selenium nanoparticles in immunological and oxidative stress generated by enrofloxacin in broiler chicken.

    PubMed

    Shirsat, Shubhangi; Kadam, Ambadas; Mane, Rajaram S; Jadhav, Vijaykumar V; Zate, Manohar K; Naushad, Mu; Kim, Kwang Ho

    2016-06-07

    Presently most bacteria are becoming antibiotic resistant. Due to this there is a deficiency of potent antibiotics, therefore we have to preserve and improve the efficiency of existing antibiotics by mitigating the side effects. Enrofloxacin (EFX) is an important antimicrobial used in veterinary practice but it is known to exert immune suppression antioxidant stress. In the present study, we report on: (a) the biosynthesis of selenium nanoparticles (Se NPs), and (b) their protective effect in reducing adverse effects of EFX on broiler chicken. A potent bacterial strain, isolated from farm soil, has been identified as Pantoea agglomerans (GenBank: KU500622). It tolerates a high concentration of selenium dioxide (9 mM) and produces Se NPs under aerobic conditions. The obtained Se NPs are amorphous in structure and spherical in shape with sizes of less than 100 nm. The activity of cellular, humoral immune response and enzymatic and non-enzymatic antioxidants, has significantly been decreased as a result of EFX treatment. We investigated that Se NP supplementation greatly restores these values towards the control, and to even higher than those of the control. Adverse effects of EFX are prevented by simultaneous exposure to Se NPs (0.6 mg per kg of feed) in the diet of poultry chicken.

  7. Biotreatment of industrial olive washing water by synergetic association of microalgal-bacterial consortia in a photobioreactor.

    PubMed

    Maza-Márquez, P; González-Martínez, A; Martínez-Toledo, M V; Fenice, M; Lasserrot, A; González-López, J

    2017-01-01

    This study presents an effective technology for the olive processing industry to remediate olive washing water. A 14.5-L enclosed tubular photobioreactor was inoculated with a stable microalgal-bacterial consortium obtained by screening strains well adapted to olive washing water. The capacity of an enclosed tubular photobioreactor to remove toxic compounds was evaluated under photosynthesis conditions and without any external supply of oxygen. The results showed that the dominant green microalgae Scenedesmus obliquus, Chlorella vulgaris and the cyanobacteria Anabaena sp. and bacteria present in olive washing water (i.e. Pantoea agglomerans and Raoultella terrigena) formed a synergistic association that was resistant to toxic pollutants present in the effluent and during the initial biodegradation process, which resulted in the breakdown of the pollutant. Total phenolic compounds, COD, BOD5, turbidity and colour removals of 90.3 ± 11.4, 80.7 ± 9.7, 97.8 ± 12.7, 82.9 ± 8.4 and 83.3 ± 10.4 %, respectively, were recorded in the photobioreactor at 3 days of hydraulic retention time. Graphical abstract Biotreatment of industrial olive washing water by synergetic association of microalgal-bacterial consortia in a photobioreactor.

  8. Simultaneous profiling of seed-associated bacteria and fungi reveals antagonistic interactions between microorganisms within a shared epiphytic microbiome on Triticum and Brassica seeds.

    PubMed

    Links, Matthew G; Demeke, Tigst; Gräfenhan, Tom; Hill, Janet E; Hemmingsen, Sean M; Dumonceaux, Tim J

    2014-04-01

    In order to address the hypothesis that seeds from ecologically and geographically diverse plants harbor characteristic epiphytic microbiota, we characterized the bacterial and fungal microbiota associated with Triticum and Brassica seed surfaces. The total microbial complement was determined by amplification and sequencing of a fragment of chaperonin 60 (cpn60). Specific microorganisms were quantified by qPCR. Bacteria and fungi corresponding to operational taxonomic units (OTU) that were identified in the sequencing study were isolated and their interactions examined. A total of 5477 OTU were observed from seed washes. Neither total epiphytic bacterial load nor community richness/evenness was significantly different between the seed types; 578 OTU were shared among all samples at a variety of abundances. Hierarchical clustering revealed that 203 were significantly different in abundance on Triticum seeds compared with Brassica. Microorganisms isolated from seeds showed 99-100% identity between the cpn60 sequences of the isolates and the OTU sequences from this shared microbiome. Bacterial strains identified as Pantoea agglomerans had antagonistic properties toward one of the fungal isolates (Alternaria sp.), providing a possible explanation for their reciprocal abundances on both Triticum and Brassica seeds. cpn60 enabled the simultaneous profiling of bacterial and fungal microbiota and revealed a core seed-associated microbiota shared between diverse plant genera.

  9. [Polyvalence of bacteriophages isolated from fruit trees, affected by bacterial fire blight].

    PubMed

    Tovkach, F I; Moroz, S N; Korol', N A; Faĭdiuk, Iu V; Kushkina, A I

    2013-01-01

    Phage populations appearing as a result of a pathogenic process caused by Erwinia amylovora have been discovered and described. They accompany bacterial fire blight development in the process of quince, pear and apple trees vegetation in Zakarpattya region of Ukraine. Phage isolates of the affected pear and quince include polyvalent virulent phages able to develop on bacterial strains associated with plants--E. amylovora. E. "horticola" and Pantoea agglomerans. E. amylovora isolated from the plant tissues affected by the fire blight and detected at the same time as phages proved to be resistant to the viral infection. It is hard to explain now this characteristic however it was noticed that resistance to phages can change drastically in case of dissociation, lysogenization and mutagenesis of erwinia in laboratory conditions. Phage population study shows that they are heterogeneous and can obviously include not only polyvalent but also specific viruses. Further studies of biology and molecular genetics of pure lines of isolated phages will help to get closer to understanding the place and role of bacteriophages in the complicated network of relations between bacterial pathogens and plants.

  10. Simultaneous profiling of seed-associated bacteria and fungi reveals antagonistic interactions between microorganisms within a shared epiphytic microbiome on Triticum and Brassica seeds

    PubMed Central

    Links, Matthew G; Demeke, Tigst; Gräfenhan, Tom; Hill, Janet E; Hemmingsen, Sean M; Dumonceaux, Tim J

    2014-01-01

    In order to address the hypothesis that seeds from ecologically and geographically diverse plants harbor characteristic epiphytic microbiota, we characterized the bacterial and fungal microbiota associated with Triticum and Brassica seed surfaces. The total microbial complement was determined by amplification and sequencing of a fragment of chaperonin 60 (cpn60). Specific microorganisms were quantified by qPCR. Bacteria and fungi corresponding to operational taxonomic units (OTU) that were identified in the sequencing study were isolated and their interactions examined. A total of 5477 OTU were observed from seed washes. Neither total epiphytic bacterial load nor community richness/evenness was significantly different between the seed types; 578 OTU were shared among all samples at a variety of abundances. Hierarchical clustering revealed that 203 were significantly different in abundance on Triticum seeds compared with Brassica. Microorganisms isolated from seeds showed 99–100% identity between the cpn60 sequences of the isolates and the OTU sequences from this shared microbiome. Bacterial strains identified as Pantoea agglomerans had antagonistic properties toward one of the fungal isolates (Alternaria sp.), providing a possible explanation for their reciprocal abundances on both Triticum and Brassica seeds. cpn60 enabled the simultaneous profiling of bacterial and fungal microbiota and revealed a core seed-associated microbiota shared between diverse plant genera. PMID:24444052

  11. Characterization of a new ViI-like Erwinia amylovora bacteriophage phiEa2809.

    PubMed

    Lagonenko, Alexander L; Sadovskaya, Olga; Valentovich, Leonid N; Evtushenkov, Anatoly N

    2015-04-01

    Erwinia amylovora is a Gram-negative plant pathogenic bacteria causing fire blight disease in many Rosaceae species. A novel E. amylovora bacteriophage, phiEa2809, was isolated from symptomless apple leaf sample collected in Belarus. This phage was also able to infect Pantoea agglomerans strains. The genome of phiEa2809 is a double-stranded linear DNA 162,160 bp in length, including 145 ORFs and one tRNA gene. The phiEa2809 genomic sequence is similar to the genomes of the Serratia plymutica phage MAM1, Shigella phage AG-3, Dickeya phage vB DsoM LIMEstone1 and Salmonella phage ViI and lacks similarity to described E. amylovora phage genomes. Based on virion morphology (an icosahedral head, long contractile tail) and genome structure, phiEa2809 was classified as a member of Myoviridae, ViI-like bacteriophages group. PhiEa2809 is the firstly characterized ViI-like bacteriophage able to lyse E. amylovora.

  12. 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.

  13. 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.

  14. 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

  15. 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

  16. 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

  17. What Are Sprains and Strains?

    MedlinePlus

    ... hands and arms a lot. Examples are gymnastics, tennis, rowing, and golf. People who play these sports sometimes strain their hand or arm. Elbow strains can also happen when playing sports. What ...

  18. Occurrence of indole-3-acetic Acid-producing bacteria on pear trees and their association with fruit russet.

    PubMed

    Lindow, S E; Desurmont, C; Elkins, R; McGourty, G; Clark, E; Brandl, M T

    1998-11-01

    ABSTRACT A relatively high percentage of epiphytic bacteria on pear leaf and fruit surfaces had the ability to produce indole-3-acetic acid (IAA) in culture media supplemented with tryptophan. While over 50% of the strains produced at least small amounts of IAA in culture, about 25% of the strains exhibited high IAA production as evidenced by both colorimetric and high-performance liquid chromatography analysis of culture supernatants. A majority of the strains that produced high amounts of IAA were identified as Erwinia herbicola (Pantoea agglomerans), while some strains of Pseudomonas syringae, Pseudomonas viridiflava, Pseudomonas fluorescens, Pseudomonas putida, and Rahnella aquaticus that produced high amounts of IAA also were found on pear. Fruit russeting was significantly increased in 39 out of 46 trials over an 8-year period in which IAA-producing bacteria were applied to trees compared with control trees. A linear relationship was observed between fruit russet severity and the logarithm of the population size of different IAA-producing bacteria on trees in the 30 days after inoculation, when normalized for the amount of IAA produced by each strain in culture. On average, the severity of fruit russet was only about 77% that on control trees when trees were treated at the time of bloom with Pseudomonas fluorescens strain A506, which does not produce IAA. Both total bacterial populations on pear in the 30-day period following full bloom and fruit russet severity varied greatly from year to year and in different commercial orchards over a 10-year period. There was a strong linear correlation between the logarithm of total bacterial population sizes and fruit russet severity.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. [Cloning and function identification of gene 'admA' and up-stream regulatory sequence related to antagonistic activity of Enterobacter cloacae B8].

    PubMed

    Zhu, Jun-Li; Li, De-Bao; Yu, Xu-Ping

    2012-04-01

    To reveal the antagonistic mechanism of B8 strain to Xanthomonas oryzae pv. oryzae, transposon tagging method and chromosome walking were deployed to clone antagonistic related fragments around Tn5 insertion site in the mutant strain B8B. The function of up-stream regulatory sequence of gene 'admA' involved in the antagonistic activity was further identified by gene knocking out technique. An antagonistic related left fragment of Tn5 insertion site, 2 608 bp in length, was obtained by tagging with Kan resistance gene of Tn5. A 2 354 bp right fragment of Tn5 insertion site was amplified with 2 rounds of chromosome walking. The length of the B contig around the Tn5 insertion site was 4 611 bp, containing 7 open reading frames (ORFs). Bioinformatic analysis revealed that these ORFs corresponded to the partial coding regions of glyceraldehyde-3-phosphate dehydrogenase, two LysR family transcriptional regulators, hypothetical protein VSWAT3-20465 of Vibrionales and admA, admB, and partial sequence of admC gene of Pantoea agglomerans biosynthetic gene cluster, respectively. Tn5 was inserted in the up-stream of 200 bp or 894 bp of the sequence corresponding to anrP ORF or admA gene on B8B, respectively. The B-1 and B-2 mutants that lost antagonistic activity were selected by homeologuous recombination technology in association with knocking out plasmid pMB-BG. These results suggested that the transcription and expression of anrP gene might be disrupted as a result of the knocking out of up-stream regulatory sequence by Tn5 in B8B strain, further causing biosythesis regulation of the antagonistic related gene cluster. Thus, the antagonistic related genes in B8 strain is a gene family similar as andrimid biosynthetic gene cluster, and the upstream regulatory region appears to be critical for the antibiotics biosynthesis.

  7. 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.

  8. 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.

  9. 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

  10. 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)

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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)

  1. 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

  2. HIGH-TEMPERATURE STRAIN GAGE,

    DTIC Science & Technology

    The patent involves a high-temperature tensometer consisting of a strain-sensitive wire grid, a connecting and insulating material, a sub-layer of...heat-resistant material, deposited on the part being investigated or on a backing by gas flame deposition, and a connector to fasten the strain...adhesion, the tension-sensitive wire grid is fastened through the sub-layer to the part being tested by the connecting and insulating material. (Author)

  3. NUTRITION OF FIVE BACTEROIDES STRAINS

    PubMed Central

    Quinto, Grace

    1962-01-01

    Quinto, Grace (University of Kentucky College of Medicine, Lexington). Nutrition of five Bacteroides strains. J. Bacteriol. 84:559–562. 1962.—Some of the nutritional requirements of five gram-negative anaerobic bacilli, including Ristella perfoetens, Zuberella clostridiformis, and three Bacteroides strains freshly isolated from clinical exudates, were investigated. A fluid maintenance medium was developed in which the three freshly isolated strains, C-4, C-7, and C-2795, grew maximally in 12 to 24 hr. The maintenance medium contained 2.0% Trypticase and Proteose Peptone, 0.5% glucose, and 0.1% sodium thioglycolate; it was adjusted to pH 7.2 and supplemented with 0.1 μg of hemin/ml. Strains C-4, C-7, and C-2795 were cultivated through 14 serial cultures in fluid maintenance medium containing 0.1 μg of hemin/ml. The most satisfactory inoculum was a 1:100 or 1:1,000 dilution of a 24-hr seed culture. All the strains except Z. clostridiformis grew serially in a defined medium. R. perfoetens required pantothenic acid, nicotinic acid, and the following amino acids: histidine, tryptophan, tyrosine, valine, phenylalanine, cystine, and probably arginine, glutamic acid, methionine, glycine, isoleucine, leucine, and lysine. The C-4, C-7, and C-2795 strains required the hemin supplement in defined medium, but not vitamins, purines, or pyrimidines. PMID:13972793

  4. 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.

  5. 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.

  6. 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).

  7. 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.

  8. Bacillus spore classification via surface-enhanced Raman spectroscopy and principal component analysis.

    PubMed

    Guicheteau, J; Argue, L; Emge, D; Hyre, A; Jacobson, M; Christesen, S

    2008-03-01

    Surface-enhanced Raman spectroscopy (SERS) can provide rapid fingerprinting of biomaterial in a nondestructive manner. The adsorption of colloidal silver to biological material suppresses native biofluorescence while providing electromagnetic surface enhancement of the normal Raman signal. This work validates the applicability of qualitative SER spectroscopy for analysis of bacterial species by utilizing principal component analysis (PCA) to show discrimination of biological threat simulants, based upon multivariate statistical confidence limits bounding known data clusters. Gram-positive Bacillus spores (Bacillus atrophaeus, Bacillus anthracis, and Bacillus thuringiensis) are investigated along with the Gram-negative bacterium Pantoea agglomerans.

  9. Principal component analysis of bacteria using surface-enhanced Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Guicheteau, Jason; Christesen, Steven D.

    2006-05-01

    Surface-enhanced Raman scattering (SERS) provides rapid fingerprinting of biomaterial in a non-destructive manner. The problem of tissue fluorescence, which can overwhelm a normal Raman signal from biological samples, is largely overcome by treatment of biomaterials with colloidal silver. This work presents a study into the applicability of qualitative SER spectroscopy with principal component analysis (PCA) for the discrimination of four biological threat simulants; Bacillus globigii, Pantoea agglomerans, Brucella noetomae, and Yersinia rohdei. We also demonstrate differentiation of gram-negative and gram-positive species and as well as spores and vegetative cells of Bacillus globigii.

  10. Non-pathogenic microflora of a spring water with regenerative properties

    PubMed Central

    NICOLETTI, GIOVANNI; CORBELLA, MARTA; JABER, OMAR; MARONE, PIERO; SCEVOLA, DANIELE; FAGA, ANGELA

    2015-01-01

    The Comano spring water (Comano, Italy) has been demonstrated to improve skin regeneration, not only by increasing keratinocyte proliferation and migration, but also by modulating the regenerated collagen and elastic fibers in the dermis. However, such biological properties may not be entirely explained by its mineral composition only. As the non-pathogenic bacterial populations have demonstrated an active role in different biological processes, the potential presence of non-pathogenic bacterial species within the Comano spring water was investigated in order to identify any possible correlation between these bacterial populations and the demonstrated biological properties of this water. The water was collected at the spring using an aseptic procedure and multiple cultures were carried out. A total of 9 different strains were isolated, which were Aeromonas hydrophila, Brevundimonas vesicularis, Chromobacterium violaceum, Citrobacter youngae, Empedobacter brevis, Pantoea agglomerans, Pseudomonas putida, Pseudomonas stutzeri and Streptococcus mitis. All the isolated bacterial strains, although showing a rare potential virulence, demonstrated peculiar and favorable metabolic attitudes in controlling environmental pollution. The therapeutical effects of certain spring waters are currently being proven as correlated not only to their peculiar mineral composition, but also to the complex activity of their resident non-pathogenic bacterial populations. Although the present study provided only preliminary data, some of the non-pathogenic bacterial populations that were identified in the Comano spring water are likely to produce molecular mediators with a role in the wound healing process that, thus far, remain unknown. Numerous other unknown bacterial species, comprehensively termed DNA-rich ‘dark matter’, are likely to contribute to the Comano water regenerative properties as well. Therefore, the non-pathogenic bacterial populations of the Comano spring water are

  11. Non-pathogenic microflora of a spring water with regenerative properties.

    PubMed

    Nicoletti, Giovanni; Corbella, Marta; Jaber, Omar; Marone, Piero; Scevola, Daniele; Faga, Angela

    2015-11-01

    The Comano spring water (Comano, Italy) has been demonstrated to improve skin regeneration, not only by increasing keratinocyte proliferation and migration, but also by modulating the regenerated collagen and elastic fibers in the dermis. However, such biological properties may not be entirely explained by its mineral composition only. As the non-pathogenic bacterial populations have demonstrated an active role in different biological processes, the potential presence of non-pathogenic bacterial species within the Comano spring water was investigated in order to identify any possible correlation between these bacterial populations and the demonstrated biological properties of this water. The water was collected at the spring using an aseptic procedure and multiple cultures were carried out. A total of 9 different strains were isolated, which were Aeromonas hydrophila, Brevundimonas vesicularis, Chromobacterium violaceum, Citrobacter youngae, Empedobacter brevis, Pantoea agglomerans, Pseudomonas putida, Pseudomonas stutzeri and Streptococcus mitis. All the isolated bacterial strains, although showing a rare potential virulence, demonstrated peculiar and favorable metabolic attitudes in controlling environmental pollution. The therapeutical effects of certain spring waters are currently being proven as correlated not only to their peculiar mineral composition, but also to the complex activity of their resident non-pathogenic bacterial populations. Although the present study provided only preliminary data, some of the non-pathogenic bacterial populations that were identified in the Comano spring water are likely to produce molecular mediators with a role in the wound healing process that, thus far, remain unknown. Numerous other unknown bacterial species, comprehensively termed DNA-rich 'dark matter', are likely to contribute to the Comano water regenerative properties as well. Therefore, the non-pathogenic bacterial populations of the Comano spring water are possibly

  12. Bacteriophages of Erwinia amylovora

    PubMed Central

    Gill, J. J.; Svircev, A. M.; Smith, R.; Castle, A. J.

    2003-01-01

    Fifty bacteriophage isolates of Erwinia amylovora, the causal agent of fire blight, were collected from sites in and around the Niagara region of southern Ontario and the Royal Botanical Gardens, Hamilton, Ontario. Forty-two phages survived the isolation, purification, and storage processes. The majority of the phages in the collection were isolated from the soil surrounding trees exhibiting fire blight symptoms. Only five phages were isolated from infected aerial tissue in pear and apple orchards. To avoid any single-host selection bias, six bacterial host strains were used in the initial isolation and enrichment processes. Molecular characterization of the phages with a combination of PCR and restriction endonuclease digestions showed that six distinct phage types, described as groups 1 to 6, were recovered. Ten phage isolates were related to the previously characterized E. amylovora PEa1, with some divergence of molecular markers between phages isolated from different sites. A study of the host ranges of the phages revealed that certain types were unable to efficiently lyse some E. amylovora strains and that some isolates were able to lyse the epiphytic bacterium Pantoea agglomerans. Representatives from the six molecular groups were studied by electron microscopy to determine their morphology. The phages exhibited distinct morphologies when examined by an electron microscope. Group 1 and 2 phages were tailed and contractile, and phages belonging to groups 3 to 6 had short tails or openings with thin appendages. Based on morphotypes, the bacteriophages of E. amylovora were placed in the order Caudovirales, in the families Myoviridae and Podoviridae. PMID:12676693

  13. Detection of carboxylesterase and esterase activity in culturable gut bacterial flora isolated from diamondback moth, Plutella xylostella (Linnaeus), from India and its possible role in indoxacarb degradation.

    PubMed

    Ramya, Shanivarsanthe Leelesh; Venkatesan, Thiruvengadam; Srinivasa Murthy, Kottilingam; Jalali, Sushil Kumar; Verghese, Abraham

    2016-01-01

    Diamondback moth (DBM), Plutella xylostella (Linnaeus), is a notorious pest of brassica crops worldwide and is resistant to all groups of insecticides. The insect system harbors diverse groups of microbiota, which in turn helps in enzymatic degradation of xenobiotic-like insecticides. The present study aimed to determine the diversity of gut microflora in DBM, quantify esterase activity and elucidate their possible role in degradation of indoxacarb. We screened 11 geographic populations of DBM in India and analyzed them for bacterial diversity. The culturable gut bacterial flora underwent molecular characterization with 16S rRNA. We obtained 25 bacterial isolates from larvae (n=13) and adults (n=12) of DBM. In larval gut isolates, gammaproteobacteria was the most abundant (76%), followed by bacilli (15.4%). Molecular characterization placed adult gut bacterial strains into three major classes based on abundance: gammaproteobacteria (66%), bacilli (16.7%) and flavobacteria (16.7%). Esterase activity from 19 gut bacterial isolates ranged from 0.072 to 2.32μmol/min/mg protein. Esterase bands were observed in 15 bacterial strains and the banding pattern differed in Bacillus cereus - KC985225 and Pantoea agglomerans - KC985229. The bands were characterized as carboxylesterase with profenofos used as an inhibitor. Minimal media study showed that B. cereus degraded indoxacarb up to 20%, so it could use indoxacarb for metabolism and growth. Furthermore, esterase activity was greater with minimal media than control media: 1.87 versus 0.26μmol/min/mg protein. Apart from the insect esterases, bacterial carboxylesterase may aid in the degradation of insecticides in DBM.

  14. Characterization of the cultivable microbiota of sprouts and their potential for application as protective cultures.

    PubMed

    Weiss, Alexander; Hertel, Christian; Grothe, Silke; Ha, Diep; Hammes, Walter P

    2007-09-01

    The microbiota of ten seeds and ready-to-eat sprouts produced thereof was characterized by bacteriological culture and denaturing gradient gel electrophoresis (DGGE) of amplified DNA fragments of the 16S rRNA gene. The predominant bacterial biota of hydroponically grown sprouts mainly consisted of enterobacteria, pseudomonades and lactic acid bacteria (LAB). For adzuki, alfalfa, mung bean, radish, sesame and wheat, the ratio of these bacterial groups changed strongly in the course of germination, whereas for broccoli, red cabbage, rye and green pea the ratio remained unchanged. Within the pseudomonades, Pseudomonas gesardii and Pseudomonas putida have been isolated and strains of the potentially pathogenic species Enterobacter cancerogenes and Pantoea agglomerans were found as part of the main microbiota on hydroponically grown sprouts. In addition to the microbiota of the whole seedlings, the microbiota of root, hypocotyl and seed leafs were examined for alfalfa, radish and mung bean sprouts. The highest and lowest total counts for aerobic bacteria were found on seed leafs and hypocotyls, respectively. On the other hand, the highest numbers for LAB on sprouts were found on the hypocotyl. When sprouting occurred under the agricultural conditions, e.g. in soil, the dominating microbiota changed from enterobacteria to pseudomonades for mung beans and alfalfa sprouts. No pathogenic enterobacteria have been isolated from these sprout types. Within the pseudomonades group, Pseudomonas jessenii and Pseudomonas brassicacearum were found as dominating species on all seedling parts from soil samples. In practical experiments, a strain of P. jessenii was found to exhibit a potential for use as protective culture, as it suppresses the growth of pathogenic enterobacteria on ready-to-eat sprouts.

  15. 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.

  16. 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

  17. 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

  18. 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)

  19. Bacteriocins and novel bacterial strains.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  20. Extreme Temperature Strain Measurement System

    DTIC Science & Technology

    1990-08-01

    Electrix Industries, Inc., P.O. Box 306, Lombard, IL 60148, Phone (312) 627-6802 38 Foil Strain gages. ° HiTEC Corp., Nardone Industrial Park...Planer Ltd., CERL-Planer Capacitive Transducer, Windmill Road, Sunbury -on- Thames, Middx., England, Phone: Sunbury 86262-3-4-5 • HiTEC Corp., Nardone

  1. 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.

  2. 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.

  3. 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 ...

  4. 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

  5. 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.

  6. 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

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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 ...

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  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. Antigenic differentiation of classical swine fever vaccinal strain PAV-250 from other strains, including field strains from Mexico.

    PubMed

    Mendoza, Susana; Correa-Giron, Pablo; Aguilera, Edgar; Colmenares, Germán; Torres, Oscar; Cruz, Tonatiuh; Romero, Andres; Hernandez-Baumgarten, Eliseo; Ciprián, Abel

    2007-10-10

    Twenty-nine classical swine fever virus (CSFv) strains were grown in the PK15 or SK6 cell lines. Antigenic differentiation studies were performed using monoclonal antibodies (McAbs), produced at Lelystad (CDI-DLO), The Netherlands. The monoclonals which were classified numerically as monoclonals 2-13. Epitope map patterns that resulted from the reactivity with McAbs were found to be unrelated to the pathogenicity of the viruses studied. Antigenic determinants were recognized by McAbs 5 and 8, were not detected in some Mexican strains; however, sites for McAb 6 were absent in all strains. The PAV-250 vaccine strain was recognized by all MAbs, except by MAb 6. Furthermore, the Chinese C-S vaccine strain was found to be very similar to the GPE(-) vaccine. None of the studied Mexican vaccines or field strains was found to be similar to the PAV-250 vaccine strain.

  20. Microbial diversity observed during hemp retting.

    PubMed

    Ribeiro, Alexandra; Pochart, Philippe; Day, Arnaud; Mennuni, Sarah; Bono, Pierre; Baret, Jean-Luc; Spadoni, Jean-Louis; Mangin, Irène

    2015-05-01

    Historically used in textile and paper industry, hemp fibres have started to find new applications in composite materials with important economic and ecological advantages. However, their applications are limited since manufacturers have some difficulties to standardise fabrication processes. This study is a first step before selection and isolation of strains that could later be used to optimise microbial retting efficiency and hence fibre quality. We studied six samples harvested on different ground types, at different dates and with different retting durations on field to obtain an exhaustive representation of the process. After DNA extraction, total bacteria and fungi associated with stems during retting were specifically quantified using real-time PCR. Then, using sequence analysis of randomly cloned 16S and 18S ribosomal RNA (rRNA) genes, a phylogenetic characterisation of the dominant microorganisms was carried out. Quantitatively, we showed that there were 8.1-9.5 log₁₀ 16S rRNA gene copies per gram of hemp straw for bacteria and 8.6-9.6 log₁₀ 18S rRNA gene copies per gram for fungi. Qualitatively, we noticed a higher bacterial diversity in comparison to fungi. This work showed that in the different samples, the same species were present but in significantly different proportions according to ground type, harvest dates and retting durations on field. The most frequent bacterial sequences were affiliated to species Escherichia coli, Pantoea agglomerans, Pseudomonas rhizosphaerae, Rhodobacter sp., Pseudomonas fulva, Rhizobium huautlense and Massilia timonae, whereas fungal sequences were principally related to the genera Cladosporium and Cryptococcus.

  1. Prevalence of bacterial resistance within an eco-agricultural system in Hangzhou, China.

    PubMed

    Xu, Like; Qian, Yanyun; Su, Chao; Cheng, Weixiao; Li, Jianan; Wahlqvist, Mark L; Chen, Hong

    2016-11-01

    The wide use of antibiotics in the animal husbandry and the relevant sustainable industries may promote the emergence of antibiotic-resistant bacteria (ARB), which constitutes a growing threat to human health. The objective of this study was to determine the abundance and diversity of sulfonamide- and tetracycline-resistant bacteria within an eco-agricultural system (EAS) in Hangzhou, China. We investigated samples at every link in the EAS, from livestock manure, to biogas residues and biogas slurry, to vegetable and ryegrass fields, to a fish pond. A combination of culture-based and 16S rRNA gene-based sequencing method was used in this study. Within the studied system, the average rate of bacterial resistance to sulfonamide (46.19 %) was much higher than that of tetracycline (8.51 %) (p < 0.01). There were 224 isolates that were enumerated and sequenced, 108 of which were identified to species level. The genera comprising the sulfamethoxazole-resistant (SMX(r)) bacteria were generally different from those of tetracycline-resistant (TC(r)) bacteria. Staphylococcus and Acinetobacter were the most dominant genera of SMX(r) bacteria (19.30 % of the total resistant bacteria) and TC(r) bacteria (14.04 % of the total resistant bacteria), respectively. Several strains of resistant opportunistic pathogens (e.g., Pantoea agglomerans) were detected in edible vegetable samples, which may exert a potential threat to both pig production and human health. In general, this study indicates that the EAS is an important reservoir of antibiotic-resistant bacteria, some of which may be pathogenic.

  2. Bacteria in a wood fungal disease: characterization of bacterial communities in wood tissues of esca-foliar symptomatic and asymptomatic grapevines

    PubMed Central

    Bruez, Emilie; Haidar, Rana; Alou, Maryam T.; Vallance, Jessica; Bertsch, Christophe; Mazet, Flore; Fermaud, Marc; Deschamps, Alain; Guerin-Dubrana, Lucia; Compant, Stéphane; Rey, Patrice

    2015-01-01

    Esca is a grapevine trunk disease (GTD) associated with different pathogenic fungi inhabiting the woody tissues. Bacteria can also be found in such tissues and they may interact with these fungal colonizers. Although such types of microbial interactions have been observed for wood diseases in many trees, this has never been studied for grapevine. In this study, the bacterial microflora of different vine status (esca-symptomatic and asymptomatic), different anatomical part (trunk and cordon) and different type of tissues (necrotic or not) have been studied. Based on Single Strand Conformation Polymorphism (SSCP) analyses, data showed that (i) specific complexes of bacterial microflora colonize the wood of both necrotic and non-necrotic tissues of esca-foliar symptomatic and asymptomatic vines, and also that (ii) depending on the anatomical part of the plant, cordon or trunk, differences could be observed between the bacterial communities. Such differences were also revealed through the community-level physiological profiling (CLPP) with Biolog EcoplatesTM. Two hundred seventeen bacterial strains were also isolated from plant samples and then assigned to bacterial species based on the 16S rRNA genes. Although Bacillus sp. and Pantoea agglomerans were the two most commonly isolated species from all kinds of tissues, various other taxa were also isolated. Inoculation of vine cuttings with 14 different bacterial species, and one GTD fungus, Neofusicoccum parvum, showed no impact of these bacteria on the size of the wood necroses caused by N. parvum. This study showed, therefore, that bacterial communities differ according to the anatomical part (trunk or cordon) and/or the type of tissue (necrotic or non-necrotic) of wood of grapevine plants showing external symptoms of esca disease. However, research into bacteria having a role in GTD development needs further studies. PMID:26579076

  3. Assembly of functional photosystem complexes in Rhodobacter sphaeroides incorporating carotenoids from the spirilloxanthin pathway.

    PubMed

    Chi, Shuang C; Mothersole, David J; Dilbeck, Preston; Niedzwiedzki, Dariusz M; Zhang, Hao; Qian, Pu; Vasilev, Cvetelin; Grayson, Katie J; Jackson, Philip J; Martin, Elizabeth C; Li, Ying; Holten, Dewey; Neil Hunter, C

    2015-02-01

    Carotenoids protect the photosynthetic apparatus against harmful radicals arising from the presence of both light and oxygen. They also act as accessory pigments for harvesting solar energy, and are required for stable assembly of many light-harvesting complexes. In the phototrophic bacterium Rhodobacter (Rba.) sphaeroides phytoene desaturase (CrtI) catalyses three sequential desaturations of the colourless carotenoid phytoene, extending the number of conjugated carbon-carbon double bonds, N, from three to nine and producing the yellow carotenoid neurosporene; subsequent modifications produce the yellow/red carotenoids spheroidene/spheroidenone (N=10/11). Genomic crtI replacements were used to swap the native three-step Rba. sphaeroides CrtI for the four-step Pantoea agglomerans enzyme, which re-routed carotenoid biosynthesis and culminated in the production of 2,2'-diketo-spirilloxanthin under semi-aerobic conditions. The new carotenoid pathway was elucidated using a combination of HPLC and mass spectrometry. Premature termination of this new pathway by inactivating crtC or crtD produced strains with lycopene or rhodopin as major carotenoids. All of the spirilloxanthin series carotenoids are accepted by the assembly pathways for LH2 and RC-LH1-PufX complexes. The efficiency of carotenoid-to-bacteriochlorophyll energy transfer for 2,2'-diketo-spirilloxanthin (15 conjugated CC bonds; N=15) in LH2 complexes is low, at 35%. High energy transfer efficiencies were obtained for neurosporene (N=9; 94%), spheroidene (N=10; 96%) and spheroidenone (N=11; 95%), whereas intermediate values were measured for lycopene (N=11; 64%), rhodopin (N=11; 62%) and spirilloxanthin (N=13; 39%). The variety and stability of these novel Rba. sphaeroides antenna complexes make them useful experimental models for investigating the energy transfer dynamics of carotenoids in bacterial photosynthesis.

  4. Studies on the Control of Ascochyta Blight in Field Peas (Pisum sativum L.) Caused by Ascochyta pinodes in Zhejiang Province, China

    PubMed Central

    Liu, Na; Xu, Shengchun; Yao, Xiefeng; Zhang, Guwen; Mao, Weihua; Hu, Qizan; Feng, Zhijuan; Gong, Yaming

    2016-01-01

    Ascochyta blight, an infection caused by a complex of Ascochyta pinodes, Ascochyta pinodella, Ascochyta pisi, and/or Phoma koolunga, is a destructive disease in many field peas (Pisum sativum L.)-growing regions, and it causes significant losses in grain yield. To understand the composition of fungi associated with this disease in Zhejiang Province, China, a total of 65 single-pycnidiospore fungal isolates were obtained from diseased pea samples collected from 5 locations in this region. These isolates were identified as Ascochyta pinodes by molecular techniques and their morphological and physiological characteristics. The mycelia of ZJ-1 could penetrate pea leaves across the stomas, and formed specific penetration structures and directly pierced leaves. The resistance level of 23 available pea cultivars was tested against their representative isolate A. pinodes ZJ-1 using the excised leaf-assay technique. The ZJ-1 mycelia could penetrate the leaves of all tested cultivars, and they developed typical symptoms, which suggested that all tested cultivars were susceptible to the fungus. Chemical fungicides and biological control agents were screened for management of this disease, and their efficacies were further determined. Most of the tested fungicides (11 out of 14) showed high activity toward ZJ-1 with EC50 < 5 μg/mL. Moreover, fungicides, including tebuconazole, boscalid, iprodione, carbendazim, and fludioxonil, displayed more than 80% disease control efficacy under the recorded conditions. Three biocontrol strains of Bacillus sp. and one of Pantoea agglomerans were isolated from pea-related niches and significantly reduced the severity of disease under greenhouse and field conditions. To our knowledge, this is the first study on ascochyta blight in field peas, and results presented here will be useful for controlling the disease in this area. PMID:27148177

  5. Bacteria in a wood fungal disease: characterization of bacterial communities in wood tissues of esca-foliar symptomatic and asymptomatic grapevines.

    PubMed

    Bruez, Emilie; Haidar, Rana; Alou, Maryam T; Vallance, Jessica; Bertsch, Christophe; Mazet, Flore; Fermaud, Marc; Deschamps, Alain; Guerin-Dubrana, Lucia; Compant, Stéphane; Rey, Patrice

    2015-01-01

    Esca is a grapevine trunk disease (GTD) associated with different pathogenic fungi inhabiting the woody tissues. Bacteria can also be found in such tissues and they may interact with these fungal colonizers. Although such types of microbial interactions have been observed for wood diseases in many trees, this has never been studied for grapevine. In this study, the bacterial microflora of different vine status (esca-symptomatic and asymptomatic), different anatomical part (trunk and cordon) and different type of tissues (necrotic or not) have been studied. Based on Single Strand Conformation Polymorphism (SSCP) analyses, data showed that (i) specific complexes of bacterial microflora colonize the wood of both necrotic and non-necrotic tissues of esca-foliar symptomatic and asymptomatic vines, and also that (ii) depending on the anatomical part of the plant, cordon or trunk, differences could be observed between the bacterial communities. Such differences were also revealed through the community-level physiological profiling (CLPP) with Biolog Ecoplates(TM). Two hundred seventeen bacterial strains were also isolated from plant samples and then assigned to bacterial species based on the 16S rRNA genes. Although Bacillus sp. and Pantoea agglomerans were the two most commonly isolated species from all kinds of tissues, various other taxa were also isolated. Inoculation of vine cuttings with 14 different bacterial species, and one GTD fungus, Neofusicoccum parvum, showed no impact of these bacteria on the size of the wood necroses caused by N. parvum. This study showed, therefore, that bacterial communities differ according to the anatomical part (trunk or cordon) and/or the type of tissue (necrotic or non-necrotic) of wood of grapevine plants showing external symptoms of esca disease. However, research into bacteria having a role in GTD development needs further studies.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.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('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/23311782','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23311782"><span>Seasonal activity of millipedes (Diplopoda)--their economic and medical significance.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kania, Grzegorz; Kłapeć, Teresa</p> <p>2012-01-01</p> <p>The millipede Brachydesmus superus Latzel, Polydesmus inconstans Latzel (Diplopoda: Polydesmida) and Kryphioiulus occultus C. L. Koch (Diplopoda: Julida) were collected from compost in gardens in Lublin, eastern Poland. Collections were made by using pitfall traps between April - September 2009 and 2010. Brachydesmus superus, Polydesmus inconstans and Kryphioiulus occultus play a significant role in composting of plant residues. Cylindroiulus caeruleocinctus Wood and Ommatoiulus sabulosus Linnaeus (Diplopoda: Julida) were collected manually in 2009-2011 in fallows and ruderals of Lublin and Kraków. C. caeruleocinctus and O. sabulosus caused considerable nuisance during mass occurrence and migration in human residences. The sex ratio has been determined for populations of C. caeruleocinctus, total sex ratio average 1:1.46. The number of females prevailed. Millipedes of the temperate climate have two peaks in the spring and autumn pattern of activity of the year. Both common species C. caeruleocinctus and O. sabulosus were analysed bacteriologically. The millipede Cylindroiulus caeruleocinctus transmits Citrobacter freundii, <span class="hlt">Pantoea</span> <span class="hlt">agglomerans</span>, Serratia marcescens, Raoultella planticola, Salmonella arizonae. The millipede Ommatoiulus sabulosus transmits Citrobacter freundii, <span class="hlt">Pantoea</span> <span class="hlt">agglomerans</span>, Raoultella planticola and Xanthomonas maltophila.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27453567','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27453567"><span>Extracellular synthesis of cuprous selenide nanospheres by a biological-chemical coupling reduction process in an anaerobic microbial system.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yue, Lei; Wang, Jia; Qi, Shiyue; Xin, Baoping</p> <p>2016-09-01</p> <p>Biosynthesis of metal nanoparticles represents a clean, eco-friendly and sustainable "green chemistry" engineering. Lately, a number of metal selenides were successfully synthesized by biological methods. Here, cuprous selenide (Cu2 Se) nanospheres were prepared under mild conditions by a novel biological-chemical coupling reduction process. The simple process takes place between EDTA-Cu and Na2 SeO3 in presence of an alkaline solution containing NaBH4 and a selenite-reducing bacteria, <span class="hlt">Pantoea</span> <span class="hlt">agglomerans</span>. It is noteworthy that the isolated <span class="hlt">Pantoea</span> <span class="hlt">agglomerans</span> and Cu(+) ions, where the latter are obtained from reducing Cu(2+) ions by NaBH4 , play a key role, and Cu(+) ions not only can promote the generation of Se(2-) ions as a catalyst, but also can react with Se(2-) ions to form Cu2 Se. XRD pattern, SEM, and TEM images indicated that Cu2 Se nanoparticles were tetragonal crystal structure and the nanospheres diameter were about 100 nm. EDX, UV-vis, and FTIR spectra show that the biosynthesized Cu2 Se nanospheres are wrapped by protein and have a better stability. This work first proposes a new biosynthesis mechanism, and has important reference value for biological preparation of metal selenide nanomaterials. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1264-1270, 2016.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23144136','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23144136"><span>Heterologous carotenoid-biosynthetic enzymes: functional complementation and effects on carotenoid profiles in 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>Song, Gyu Hyeon; Kim, Se Hyeuk; Choi, Bo Hyun; Han, Se Jong; Lee, Pyung Cheon</p> <p>2013-01-01</p> <p>A limited number of carotenoid pathway genes from microbial sources have been studied for analyzing the pathway complementation in the heterologous host Escherichia coli. In order to systematically investigate the functionality of carotenoid pathway enzymes in E. coli, the pathway genes of carotenogenic microorganisms (Brevibacterium linens, Corynebacterium glutamicum, Rhodobacter sphaeroides, Rhodobacter capsulatus, Rhodopirellula baltica, and <span class="hlt">Pantoea</span> ananatis) were modified to form synthetic expression modules and then were complemented with <span class="hlt">Pantoea</span> <span class="hlt">agglomerans</span> pathway enzymes (CrtE, CrtB, CrtI, CrtY, and CrtZ). The carotenogenic pathway enzymes in the synthetic modules showed unusual activities when complemented with E. coli. For example, the expression of heterologous CrtEs of B. linens, C. glutamicum, and R. baltica influenced P. <span class="hlt">agglomerans</span> CrtI to convert its substrate phytoene into a rare product-3,4,3',4'-tetradehydrolycopene-along with lycopene, which was an expected product, indicating that CrtE, the first enzyme in the carotenoid biosynthesis pathway, can influence carotenoid profiles. In addition, CrtIs of R. sphaeroides and R. capsulatus converted phytoene into an unusual lycopene as well as into neurosporene. Thus, this study shows that the functional complementation of pathway enzymes from different sources is a useful methodology for diversifying biosynthesis as nature does.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3553770','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3553770"><span>Heterologous Carotenoid-Biosynthetic Enzymes: Functional Complementation and Effects on Carotenoid Profiles in Escherichia coli</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Song, Gyu Hyeon; Kim, Se Hyeuk; Choi, Bo Hyun; Han, Se Jong</p> <p>2013-01-01</p> <p>A limited number of carotenoid pathway genes from microbial sources have been studied for analyzing the pathway complementation in the heterologous host Escherichia coli. In order to systematically investigate the functionality of carotenoid pathway enzymes in E. coli, the pathway genes of carotenogenic microorganisms (Brevibacterium linens, Corynebacterium glutamicum, Rhodobacter sphaeroides, Rhodobacter capsulatus, Rhodopirellula baltica, and <span class="hlt">Pantoea</span> ananatis) were modified to form synthetic expression modules and then were complemented with <span class="hlt">Pantoea</span> <span class="hlt">agglomerans</span> pathway enzymes (CrtE, CrtB, CrtI, CrtY, and CrtZ). The carotenogenic pathway enzymes in the synthetic modules showed unusual activities when complemented with E. coli. For example, the expression of heterologous CrtEs of B. linens, C. glutamicum, and R. baltica influenced P. <span class="hlt">agglomerans</span> CrtI to convert its substrate phytoene into a rare product—3,4,3′,4′-tetradehydrolycopene—along with lycopene, which was an expected product, indicating that CrtE, the first enzyme in the carotenoid biosynthesis pathway, can influence carotenoid profiles. In addition, CrtIs of R. sphaeroides and R. capsulatus converted phytoene into an unusual lycopene as well as into neurosporene. Thus, this study shows that the functional complementation of pathway enzymes from different sources is a useful methodology for diversifying biosynthesis as nature does. PMID:23144136</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('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> </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('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('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="https://publicaccess.dtic.mil/psm/api/service/search/search">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('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> <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://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.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('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('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/2012APS..MARV27001L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012APS..MARV27001L"><span>Making Novel Materials Using <span class="hlt">Strain</span> in Nanomembranes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lagally, Max G.</p> <p>2012-02-01</p> <p>The controlled introduction of <span class="hlt">strain</span> in materials offers an important degree of freedom for fundamental studies of materials as well as advanced device engineering. <span class="hlt">Strain</span> in a crystalline solid modifies the lattice constants and reduces the crystal symmetry. Because <span class="hlt">strain</span> energy is proportional to thickness, a free-standing crystalline thin sheet, which we call a nanomembrane (NM), can be <span class="hlt">strained</span> to a greater degree that a bulk material with the same surface area. I show the use of nanomembrane <span class="hlt">strain</span> engineering to make defect-free single crystals that cannot be grown any other way, and materials with <span class="hlt">strain</span> symmetries that they do not have naturally, in both cases alloys of Si and Ge. <span class="hlt">Strain</span> in NMs causes significant shifts in energy band edges, splitting of degenerate states, and changes in effective masses. These effects can be used to produce a desired band offset between different materials, to increase carrier mobility, and to change relative energy positions of valleys. In the latter respect, through the use of NMs it has recently become possible, using tensile <span class="hlt">strain</span>, to make Ge direct-bandgap and light emitting at room temperature. Periodic local stress can produce <span class="hlt">strain</span> superlattices and thus single-element heterojunctions. Work performed with the Roberto Paiella, Mark Eriksson, Feng Liu, and Irena Knezevic research groups.</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://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('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/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/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.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('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/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> <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=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> </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('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://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('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://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('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('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://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://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/2060/19700000207','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('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://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.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('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('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.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('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('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> </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/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('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.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('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('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/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/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> <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('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.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('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('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.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.</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('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('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>... Feeding Your 1- to 2-Year-Old 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://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('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/2060/19940008401','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> </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('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('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/2060/19870019450','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://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('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('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://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('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=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('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('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://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/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> <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://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('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('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> </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('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('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=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('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('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('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('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('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('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://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; 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.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('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://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('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.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('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('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/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.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_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('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.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://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.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('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('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('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> <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('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('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('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/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('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('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('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('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('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.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> </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/2060/19950022297','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/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> <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/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('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('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.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://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('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="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</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://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://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/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('http://adsabs.harvard.edu/abs/2013AGUFM.S21A2372B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.S21A2372B"><span>Modeling <span class="hlt">Strains</span> Associated with Fluid Extraction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barbour, A. J.; Agnew, D. C.; Wyatt, F. K.</p> <p>2013-12-01</p> <p>A class of <span class="hlt">strain</span> signals found in data from a number of borehole strainmeters in the Plate Boundary Observatory network is believed to be associated with pumping of nearby water wells. In order to test the connection between fluid extraction and deformation, we have collected a multi- year record of the pump activity at two actively-pumped wells near the pair of strainmeters at the Pathfinder Ranch, a summer camp located in the Garner Valley in southern California. The data we have collected indicate strong correlations between (1) times of fluid extraction and the onset of significant <span class="hlt">strain</span> and pore-fluid pressure changes, and (2) cumulative extraction volumes and the sizes of the pressure and <span class="hlt">strain</span> perturbations. In order to model these observations, we use a sum of K autoregressive models to create a statistical description of the effect, and a poroelastic model to create a physical description. We show that for K = 2 the mixture model adequately preserves both long- and short-term effects, and can be used to construct a ';correction series' from the binary pumping series in a numerically efficient manner. Spatiotemporal <span class="hlt">strain</span> and pore- fluid pressure fields associated with episodes of fluid extraction are simulated in a layered, radially extensive poroelastic medium. Based on the interpretations of our parameter exploration, the simplest model which fits the observed <span class="hlt">strains</span> and pressures is a two layer model where rigid bedrock having relatively high diffusivity is overlain by roughly 100 meters of alluvium having slightly higher diffusivity and behaving as an unconfined aquifer system. The lack of a strong contrast in diffusivity between lithologic units suggests that the bedrock material has a relatively high density of hydraulically conductive fractures; borehole logging data and drillers' logs corroborate this. Further, the requirement that both layers have high conductivity helps explain the relatively low sensitivity of the aquifer system to dynamic</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/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.</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('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://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('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.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> </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://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('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> <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('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://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('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://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/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.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/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="https://publicaccess.dtic.mil/psm/api/service/search/search">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. The</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="https://publicaccess.dtic.mil/psm/api/service/search/search">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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5289684','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5289684"><span>Genome Sequences of Bacillus thuringiensis Serovar kurstaki <span class="hlt">Strain</span> BP865 and B. thuringiensis Serovar aizawai <span class="hlt">Strain</span> HD-133</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jeong, Haeyoung</p> <p>2017-01-01</p> <p>ABSTRACT We report the draft genome sequences of two insecticidal <span class="hlt">strains</span> against lepidopteran pests, Bacillus thuringiensis serovar kurstaki <span class="hlt">strain</span> BP865, an isolate from the South Korean phylloplane, and <span class="hlt">strain</span> HD-133, a reference <span class="hlt">strain</span> of B. thuringiensis serovar aizawai. PMID:28153898</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26186451','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26186451"><span>Multiple Comparison Analysis of Two New Genomic Sequences of ILTV <span class="hlt">Strains</span> from China with Other <span class="hlt">Strains</span> from Different Geographic Regions.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhao, Yan; Kong, Congcong; Wang, Yunfeng</p> <p>2015-01-01</p> <p>To date, twenty complete genome sequences of ILTV <span class="hlt">strains</span> have been published in GenBank, including one <span class="hlt">strain</span> from China, and nineteen <span class="hlt">strains</span> from Australian and the United States. To investigate the genomic information on ILTVs from different geographic regions, two additional individual complete genome sequences of WG and K317 <span class="hlt">strains</span> from China were determined. The genomes of WG and K317 <span class="hlt">strains</span> were 153,505 and 153,639 bp in length, respectively. Alignments performed on the amino acid sequences of the twelve glycoproteins showed that 13 out of 116 mutational sites were present only among the Chinese <span class="hlt">strain</span> WG and the Australian <span class="hlt">strains</span> SA2 and A20. The phylogenetic tree analysis suggested that the WG <span class="hlt">strain</span> established close relationships with the Australian <span class="hlt">strain</span> SA2. The recombination events were detected and confirmed in different subregions of the WG <span class="hlt">strain</span> with the sequences of SA2 and K317 <span class="hlt">strains</span> as parental. In this study, two new complete genome sequences of Chinese ILTV <span class="hlt">strains</span> were used in comparative analysis with other complete genome sequences of ILTV <span class="hlt">strains</span> from China, the United States, and Australia. The analysis of genome comparison, phylogenetic trees, and recombination events showed close relationships among the Chinese <span class="hlt">strain</span> WG and the Australian <span class="hlt">strains</span> SA2. The information of the two new complete genome sequences from China will help to facilitate the analysis of phylogenetic relationships and the molecular differences among ILTV <span class="hlt">strains</span> from different geographic regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25660626','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25660626"><span>Perceptual <span class="hlt">strain</span> index for heat <span class="hlt">strain</span> assessment in an experimental study: an application to construction workers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yang, Y; Chan, Albert P C</p> <p>2015-02-01</p> <p>Although the physiological <span class="hlt">strain</span> index (PhSI) is universal and comprehensive, its restrictions are recognized in terms of invasive on-site measurements and the requirement of accurate instruments. The perceptual <span class="hlt">strain</span> index (PeSI) has been proposed as a user-friendly and practical indicator for heat <span class="hlt">strain</span>. However, the application of this index in assessing the heat <span class="hlt">strain</span> of construction workers has yet to be examined and documented. This study aims to ascertain the reliability and applicability of PeSI in an experimental setting that simulates a stressful working environment (i.e., environment, work uniform, and work pace) experienced by construction workers. Ten males and two females performed intermittent exercise on a treadmill while wearing a summer work uniform at 34.5 °C and 75% relative humidity in a climatic chamber. Physiological parameters (core temperature, heart rate) and perceptual variables (thermal sensation, perceived exertion) were collated synchronously at 3 min intervals. The results of two-way repeated measures analysis of variance (clothing×time) revealed that the PeSI was useful in differentiating the heat <span class="hlt">strain</span> levels between different work uniforms. Not only did the PeSI change in the same general manner with the PhSI, but it was also powerful in reflecting different levels of physiological <span class="hlt">strain</span>. Thus, the PeSI offers considerable promise for heat <span class="hlt">strain</span> assessment under simulated working conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4106073','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4106073"><span>Probiotic Potential of Lactobacillus <span class="hlt">Strains</span> with Antimicrobial Activity against Some Human Pathogenic <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>Shokryazdan, Parisa; Sieo, Chin Chin; Kalavathy, Ramasamy; Liang, Juan Boo; Alitheen, Noorjahan Banu; Faseleh Jahromi, Mohammad; Ho, Yin Wan</p> <p>2014-01-01</p> <p>The objective of this study was to isolate, identify, and characterize some lactic acid bacterial <span class="hlt">strains</span> from human milk, infant feces, and fermented grapes and dates, as potential probiotics with antimicrobial activity against some human pathogenic <span class="hlt">strains</span>. One hundred and forty bacterial <span class="hlt">strains</span> were isolated and, after initial identification and a preliminary screening for acid and bile tolerance, nine of the best isolates were selected and further identified using 16 S rRNA gene sequences. The nine selected isolates were then characterized in vitro for their probiotic characteristics and their antimicrobial activities against some human pathogens. Results showed that all nine isolates belonged to the genus Lactobacillus. They were able to tolerate pH 3 for 3 h, 0.3% bile salts for 4 h, and 1.9 mg/mL pancreatic enzymes for 3 h. They exhibited good ability to attach to intestinal epithelial cells and were not resistant to the tested antibiotics. They also showed good antimicrobial activities against the tested pathogenic <span class="hlt">strains</span> of humans, and most of them exhibited stronger antimicrobial activity than the reference <span class="hlt">strain</span> L. casei Shirota. Thus, the nine Lactobacillus <span class="hlt">strains</span> could be considered as potential antimicrobial probiotic <span class="hlt">strains</span> against human pathogens and should be further studied for their human health benefits. PMID:25105147</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910010090','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910010090"><span>The apparent <span class="hlt">strain</span> stability and repeatability of a BCL3 resistance <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>Lei, Jih-Fen</p> <p>1991-01-01</p> <p>Experiments were conducted at NASA-Lewis to study the effect of microstructural instability on the apparent <span class="hlt">strain</span> stability and reproducibility of a BCL3 resistance <span class="hlt">strain</span> gage. The resistance drift of the gage at various temperatures in the phase transition temperature range (PTTR) was measured. The effects of the heating and cooling rates with which the gage passed through the PTTR on the apparent <span class="hlt">strain</span> characteristics of the gage were also studied. BCL3 gage, like other Fe-Cr-Al based gages, exhibited apparent <span class="hlt">strain</span> instability in the temperature range of 700 to 1100 F due to the reversible microstructural transition the gage materials experienced in this temperature range. The BCL3 gage had a maximum apparent <span class="hlt">strain</span> drift in the neighborhood of 770 F with an average drift rate of approx. -440 microstrain/hr in 2 hrs. The use of the BCL3 gage as well as other Fe-Cl-Al based gages for static <span class="hlt">strain</span> measurements within the PTTR should be avoided unless the time durations in the PTTR are small enough to introduce a neglible drift. The microstructure transition that the BCL3 gage underwent occurred in the temperature range of 750 to 1050 F during heating and around 1000 to 800 F during cooling. The heating rate, and, in particular, the cooling rate with which the gage passed through the PTTR affected the shape and the repeatability of the apparent <span class="hlt">strain</span> curve of the gage.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010Nanot..21m4013M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010Nanot..21m4013M"><span>Nanoscale patterning induced <span class="hlt">strain</span> redistribution in ultrathin <span class="hlt">strained</span> Si layers on oxide</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moutanabbir, O.; Reiche, M.; Hähnel, A.; Erfurth, W.; Gösele, U.; Motohashi, M.; Tarun, A.; Hayazawa, N.; Kawata, S.</p> <p>2010-04-01</p> <p>We present a comparative study of the influence of the thickness on the <span class="hlt">strain</span> behavior upon nanoscale patterning of ultrathin <span class="hlt">strained</span> Si layers directly on oxide. The <span class="hlt">strained</span> layers were grown on a SiGe virtual substrate and transferred onto a SiO2/Si substrate using wafer bonding and hydrogen ion induced exfoliation. The post-patterning <span class="hlt">strain</span> was evaluated using UV micro-Raman spectroscopy for thin (20 nm) and thick (60 nm) nanostructures with lateral dimensions in the range of 80-400 nm. We found that about 40-50% of the initial <span class="hlt">strain</span> is maintained in the 20 nm thick nanostructures, whereas this fraction drops significantly to ~ 2-20% for the 60 nm thick ones. This phenomenon of free surface induced relaxation is described using detailed three-dimensional finite element simulations. The simulated <span class="hlt">strain</span> 3D maps confirm the limited relaxation in thin nanostructures. This result has direct implications for the fabrication and manipulation of <span class="hlt">strained</span> Si nanodevices.</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/23045489','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23045489"><span>Genomic comparison of Kingella kingae <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>Fournier, Pierre-Edouard; Rouli, Laetitia; El Karkouri, Khalid; Nguyen, Thi-Tien; Yagupsky, Pablo; Raoult, Didier</p> <p>2012-11-01</p> <p>Kingella kingae is a betaproteobacterium from the order Neisseriales, and it is an agent of invasive infections in children. We sequenced the genome from the septic arthritis <span class="hlt">strain</span> 11220434. It is composed of a 1,990,794-bp chromosome but no plasmid, and it contains 2,042 protein-coding genes and 52 RNA genes, including 3 rRNA genes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EPJWC..2602006G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EPJWC..2602006G"><span>High <span class="hlt">strain</span> rate behaviour of polypropylene microfoams</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gómez-del Río, T.; Garrido, M. A.; Rodríguez, J.; Arencón, D.; Martínez, A. B.</p> <p>2012-08-01</p> <p>Microcellular materials such as polypropylene foams are often used in protective applications and passive safety for packaging (electronic components, aeronautical structures, food, etc.) or personal safety (helmets, knee-pads, etc.). In such applications the foams which are used are often designed to absorb the maximum energy and are generally subjected to severe loadings involving high <span class="hlt">strain</span> rates. The manufacture process to obtain polymeric microcellular foams is based on the polymer saturation with a supercritical gas, at high temperature and pressure. This method presents several advantages over the conventional injection moulding techniques which make it industrially feasible. However, the effect of processing conditions such as blowing agent, concentration and microfoaming time and/or temperature on the microstructure of the resulting microcellular polymer (density, cell size and geometry) is not yet set up. The compressive mechanical behaviour of several microcellular polypropylene foams has been investigated over a wide range of <span class="hlt">strain</span> rates (0.001 to 3000 s-1) in order to show the effects of the processing parameters and <span class="hlt">strain</span> rate on the mechanical properties. High <span class="hlt">strain</span> rate tests were performed using a Split Hopkinson Pressure Bar apparatus (SHPB). Polypropylene and polyethylene-ethylene block copolymer foams of various densities were considered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA573778','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA573778"><span>Rapid Parallel Screening for <span class="hlt">Strain</span> Optimization</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2013-02-19</p> <p>reporting period, we have completed screening for microbial growth and nearly finished the proposed sequencing. Sequencing would have been completed... microbial <span class="hlt">strains</span> that produce industrially relevant biochemicals routine. Recent synthetic biology techniques can make billions of variant cells...industrially relevant biomolecules) are identified using microbial growth assays, sequencing, and quantitative PCR (qPCR). To demonstrate that such</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA594001','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA594001"><span>Rapid Parallel Screening for <span class="hlt">Strain</span> Optimization</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2013-11-18</p> <p>engineering of new microbial <span class="hlt">strains</span> that produce industrially relevant biochemicals routine. Recent synthetic biology techniques can make billions of...overproduction of such molecules. Identification and experimental validation of specific sensors is indispensable but current results are promising: 1) most...target chemicals (~80%) readily produce microbial growth, 2) colony morphology, etc., suggests that different target chemicals resulted in the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=merton&pg=2&id=EJ762245','ERIC'); return false;" href="http://eric.ed.gov/?q=merton&pg=2&id=EJ762245"><span>Role <span class="hlt">Strain</span> in University Research Centers</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>Boardman, Craig; Bozeman, Barry</p> <p>2007-01-01</p> <p>One way in which university faculty members' professional lives have become more complex with the advent of contemporary university research centers is that many faculty have taken on additional roles. The authors' concern in this article is to determine the extent to which role <span class="hlt">strain</span> is experienced by university faculty members who are…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23385407','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23385407"><span>Thermal <span class="hlt">strain</span> analysis of optic fiber sensors.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Her, Shiuh-Chuan; Huang, Chih-Ying</p> <p>2013-01-31</p> <p>An optical fiber sensor surface bonded onto a host structure and subjected to a temperature change is analytically studied in this work. The analysis is developed in order to assess the thermal behavior of an optical fiber sensor designed for measuring the <span class="hlt">strain</span> in the host structure. For a surface bonded optical fiber sensor, the measuring sensitivity is strongly dependent on the bonding characteristics which include the protective coating, adhesive layer and the bonding length. Thermal stresses can be generated due to a mismatch of thermal expansion coefficients between the optical fiber and host structure. The optical fiber thermal <span class="hlt">strain</span> induced by the host structure is transferred via the adhesive layer and protective coating. In this investigation, an analytical expression of the thermal <span class="hlt">strain</span> and stress in the optical fiber is presented. The theoretical predictions are validated using the finite element method. Numerical results show that the thermal <span class="hlt">strain</span> and stress are linearly dependent on the difference in thermal expansion coefficients between the optical fiber and host structure and independent of the thermal expansion coefficients of the adhesive and coating.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/867538','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/867538"><span>Neutron apparatus for measuring <span class="hlt">strain</span> in composites</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Kupperman, David S.; Majumdar, Saurindranath; Faber, Jr., John F.; Singh, J. P.</p> <p>1990-01-01</p> <p>A method and apparatus for orienting a pulsed neutron source and a multi-angle diffractometer toward a sample of a ceramic-matrix or metal-matrix composite so that the measurement of internal <span class="hlt">strain</span> (from which stress is calculated) is reduced to uncomplicated time-of-flight measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5188875','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/5188875"><span>Superconducting wire with improved <span class="hlt">strain</span> characteristics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Luhman, T.; Klamut, C.J.; Suenaga, M.; Welch, D.</p> <p>1979-12-19</p> <p>A superconducting wire comprising a superconducting filament and a beryllium strengthened bronze matrix in which the addition of beryllium to the matrix permits a low volume matrix to exhibit reduced elastic deformation after heat treating which increases the compression of the superconducting filament on cooling and thereby improve the <span class="hlt">strain</span> characteristics of the wire.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/864172','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/864172"><span>Superconducting wire with improved <span class="hlt">strain</span> characteristics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Luhman, Thomas; Klamut, Carl J.; Suenaga, Masaki; Welch, David</p> <p>1982-01-01</p> <p>A superconducting wire comprising a superconducting filament and a beryllium strengthened bronze matrix in which the addition of beryllium to the matrix permits a low volume matrix to exhibit reduced elastic deformation after heat treating which increases the compression of the superconducting filament on cooling and thereby improve the <span class="hlt">strain</span> characteristics of the wire.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/864302','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/864302"><span>Superconducting wire with improved <span class="hlt">strain</span> characteristics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Luhman, Thomas; Klamut, Carl J.; Suenaga, Masaki; Welch, David</p> <p>1982-01-01</p> <p>A superconducting wire comprising a superconducting filament and a beryllium strengthened bronze matrix in which the addition of beryllium to the matrix permits a low volume matrix to exhibit reduced elastic deformation after heat treating which increases the compression of the superconducting filament on cooling and thereby improves the <span class="hlt">strain</span> characteristics of the wire.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..MARJ32004F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..MARJ32004F"><span>Charge and <span class="hlt">Strain</span> Control of Interface Magnetism</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fitzsimmons, M. R.; Dumesnil, K.; Jaouen, N.; Maroutian, T.; Agnus, G.; Tonnerre, J.-M.; Kirby, B.; Fohtung, E.; Holladay, B.; Fullerton, E. E.; Shpyrko, O.; Sinha, S. K.; Wang, Q.; Chen, A.; Jia, Q. X.</p> <p>2015-03-01</p> <p>We studied the influence of an electric field applied to an La0.67Sr0.33MnO3 (LSMO) layer in a LSMO/Pb(Zr0.2Ti0.8) O3 (PZT)/Nb-doped SrTiO3 (STO) heterostructure by measuring its magnetization depth profile using resonant x-ray magnetic reflectivity. The saturation magnetization of the ferromagnetically-ordered LSMO was not affected by the direction of the polarization of the PZT. However, the ferromagnetic thickness and magnetization of the LSMO film at remanence were reduced for hole-charge accumulation at the LSMO/PZT interface. To understand the independent roles of <span class="hlt">strain</span> and hole-doping, we performed neutron scattering experiments of La0.8Sr0.2MnO3 films grown on Nb-doped STO in which bending <span class="hlt">strain</span> (via 4-point bending jig) or electric field (via parallel plate capacitor) was applied to the films. We observed that bending <span class="hlt">strain</span> affects the saturation magnetization of the LSMO film, whereas electric field affects the remanent magnetization of the film. These observations suggest <span class="hlt">strain</span> may be a more effective means to control magnetism than charge. This work has benefited from use of CINT(LANL), NIST Center for Neutron Research and the Synchrotron SOLEIL and funding from LANL/LDRD program, DOE-BES (UCSD) and DOD (NMSU).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19880000040&hterms=hygroscopic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dhygroscopic','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19880000040&hterms=hygroscopic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dhygroscopic"><span><span class="hlt">Strain</span>-Energy-Release Rates In Delamination</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Raju, I. S.</p> <p>1988-01-01</p> <p>Q3DG computer program developed to perform quasi-three-dimensional stress analysis of composite laminates containing delaminations. Calculates <span class="hlt">strain</span>-energy-release rates for long, rectangular composite laminates containing delaminations and subjected to any combination of mechanical, thermal, and hygroscopic loading. Written in FORTRAN V.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21506805','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21506805"><span>Quality Control On <span class="hlt">Strained</span> Semiconductor Devices</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Dommann, Alex; Neels, Antonia</p> <p>2010-11-24</p> <p>New semiconductor devices are based very often on <span class="hlt">strained</span> silicon which promises to squeeze more device performance out of current devices. With <span class="hlt">strained</span> silicon it is possible to get the same device performance using less power. The technique is using <span class="hlt">strain</span> as a 'design element' for silicon to improve the device performance and has become a hot topic in semiconductor research in the past years. However in the same time topics like 'System in Package'(SiP) on thin wafers are getting more and more important. The chips of thin wafers in advanced packaging are extremely sensitive to induced stresses due to packaging issues. If we are using now <span class="hlt">strain</span> as a design element for improving device performance we increase the sensitivity again and therefore also the risk of aging of such SiP's. High Resolution X-ray diffraction (HRXRD) techniques such as Rocking Curves (RC's) and Reciprocal Space Mapping (RSM) are therefore very powerful tools to study the stresses in packaged devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Geote..50..336P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Geote..50..336P"><span>Prediction of swelling rocks <span class="hlt">strain</span> in tunneling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Parsapour, D.; Fahimifar, A.</p> <p>2016-05-01</p> <p>Swelling deformations leading to convergence of tunnels may result in significant difficulties during the construction, in particular for long term use of tunnels. By extracting an experimental based explicit analytical solution for formulating swelling <span class="hlt">strains</span> as a function of time and stress, swelling <span class="hlt">strains</span> are predicted from the beginning of excavation and during the service life of tunnel. Results obtained from the analytical model show a proper agreement with experimental results. This closed-form solution has been implemented within a numerical program using the finite element method for predicting time-dependent swelling <span class="hlt">strain</span> around tunnels. Evaluating effects of swelling parameters on time-dependent <span class="hlt">strains</span> and tunnel shape on swelling behavior around the tunnel according to this analytical solution is considered. The ground-support interaction and consequent swelling effect on the induced forces in tunnel lining is considered too. Effect of delay in lining installation on swelling pressure which acting on the lining and its structural integrity, is also evaluated. A MATLAB code of " SRAP" is prepared and applied to calculate all swelling analysis around tunnels based on analytical solution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JAP...118l3904D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JAP...118l3904D"><span>High <span class="hlt">strain</span>-rate magnetoelasticity in Galfenol</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Domann, J. P.; Loeffler, C. M.; Martin, B. E.; Carman, G. P.</p> <p>2015-09-01</p> <p>This paper presents the experimental measurements of a highly magnetoelastic material (Galfenol) under impact loading. A Split-Hopkinson Pressure Bar was used to generate compressive stress up to 275 MPa at <span class="hlt">strain</span> rates of either 20/s or 33/s while measuring the stress-<span class="hlt">strain</span> response and change in magnetic flux density due to magnetoelastic coupling. The average Young's modulus (44.85 GPa) was invariant to <span class="hlt">strain</span> rate, with instantaneous stiffness ranging from 25 to 55 GPa. A lumped parameters model simulated the measured pickup coil voltages in response to an applied stress pulse. Fitting the model to the experimental data provided the average piezomagnetic coefficient and relative permeability as functions of field strength. The model suggests magnetoelastic coupling is primarily insensitive to <span class="hlt">strain</span> rates as high as 33/s. Additionally, the lumped parameters model was used to investigate magnetoelastic transducers as potential pulsed power sources. Results show that Galfenol can generate large quantities of instantaneous power (80 MW/m3 ), comparable to explosively driven ferromagnetic pulse generators (500 MW/m3 ). However, this process is much more efficient and can be cyclically carried out in the linear elastic range of the material, in stark contrast with explosively driven pulsed power generators.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=270866','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=270866"><span>Genome sequence of Haemophilus parasuis <span class="hlt">strain</span> 29755</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>Haemophilus parasuis is a member of the family Pasteurellaceae and is the etiologic agent of Glasser's disease in pigs, a systemic syndrome associated with only a subset of isolates. The genetic basis for virulence and systemic spread of particular H. parasuis isolates is currently unknown. <span class="hlt">Strain</span> 2...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27714887','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27714887"><span>Highly Stretchable, <span class="hlt">Strain</span> Sensing Hydrogel Optical Fibers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Guo, Jingjing; Liu, Xinyue; Jiang, Nan; Yetisen, Ali K; Yuk, Hyunwoo; Yang, Changxi; Khademhosseini, Ali; Zhao, Xuanhe; Yun, Seok-Hyun</p> <p>2016-12-01</p> <p>A core-clad fiber made of elastic, tough hydrogels is highly stretchable while guiding light. Fluorescent dyes are easily doped into the hydrogel fiber by diffusion. When stretched, the transmission spectrum of the fiber is altered, enabling the <span class="hlt">strain</span> to be measured and also its location.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22300283','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22300283"><span><span class="hlt">Strain</span> engineering of Dirac cones in graphyne</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wang, Gaoxue; Kumar, Ashok; Pandey, Ravindra; Si, Mingsu</p> <p>2014-05-26</p> <p>6,6,12-graphyne, one of the two-dimensional carbon allotropes with the rectangular lattice structure, has two kinds of non-equivalent anisotropic Dirac cones in the first Brillouin zone. We show that Dirac cones can be tuned independently by the uniaxial compressive <span class="hlt">strain</span> applied to graphyne, which induces n-type and p-type self-doping effect, by shifting the energy of the Dirac cones in the opposite directions. On the other hand, application of the tensile <span class="hlt">strain</span> results into a transition from gapless to finite gap system for the monolayer. For the AB-stacked bilayer, the results predict tunability of Dirac-cones by in-plane <span class="hlt">strains</span> as well as the <span class="hlt">strain</span> applied perpendicular to the plane. The group velocities of the Dirac cones show enhancement in the resistance anisotropy for bilayer relative to the case of monolayer. Such tunable and direction-dependent electronic properties predicted for 6,6,12-graphyne make it to be competitive for the next-generation electronic devices at nanoscale.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/437675','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/437675"><span>Characterizing large <span class="hlt">strain</span> crush response of redwood</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cramer, S.M.; Hermanson, J.C.; McMurtry, W.M.</p> <p>1996-12-01</p> <p>Containers for the transportation of hazardous and radioactive materials incorporate redwood in impact limiters. Redwood is an excellent energy absorber, but only the most rudimentary information exists on its crush properties. The objectives of the study were to fill the information gap by collecting triaxial load-deformation data for redwood; to use these data to characterize redwood crush, assess current wood failure theories, provide developments toward a complete stress-<span class="hlt">strain</span> theory for redwood; and to review the literature on <span class="hlt">strain</span>-rate effects on redwood crush performance. The load-deformation responses of redwood at temperature conditions corresponding to ambient (70{degrees}F), 150{degrees}F, and {minus}20{degrees}F conditions were measured in approximately 100 confined compression tests for crush levels leading to material densification. Data analysis provided a more complete description of redwood crush performance and a basis for assessing proposed general orthotropic stress-<span class="hlt">strain</span> relationships for redwood. A review of existing literature indicated that <span class="hlt">strain</span>-rate effects cause at most a 20 percent increase in crush stress parallel to grain.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5228237','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5228237"><span>Identification of <span class="hlt">Strain</span>-Specific Sequences That Distinguish a Mycoplasma gallisepticum Vaccine <span class="hlt">Strain</span> from Field Isolates</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ricketts, Camir; Pickler, Larissa; Maurer, John; Ayyampalayam, Saravanaraj; García, Maricarmen</p> <p>2016-01-01</p> <p>ABSTRACT Despite attempts to control avian mycoplasmosis through management, vaccination, and surveillance, Mycoplasma gallisepticum continues to cause significant morbidity, mortality, and economic losses in poultry production. Live attenuated vaccines are commonly used in the poultry industry to control avian mycoplasmosis; unfortunately, some vaccines may revert to virulence and vaccine <span class="hlt">strains</span> are generally difficult to distinguish from natural field isolates. In order to identify genome differences among vaccine revertants, vaccine <span class="hlt">strains</span>, and field isolates, whole-genome sequencing of the M. gallisepticum vaccine <span class="hlt">strain</span> ts-11 and several “ts-11-like” <span class="hlt">strains</span> isolated from commercial flocks was performed using Illumina and 454 pyrosequencing and the sequenced genomes compared to the M. gallisepticum Rlow reference genome. The collective contigs for each <span class="hlt">strain</span> were annotated using the fully annotated Mycoplasma reference genome. The analysis revealed genetic differences among vlhA alleles, as well as among genes annotated as coding for a cell wall surface anchor protein (mg0377) and a hypothetical protein gene, mg0359, unique to M. gallisepticum ts-11 vaccine <span class="hlt">strain</span>. PCR protocols were designed to target 5 sequences unique to the M. gallisepticum ts-11 <span class="hlt">strain</span>: vlhA3.04a, vlhA3.04b, vlhA3.05, mg0377, and mg0359. All ts-11 isolates were positive for the five gene alleles tested by PCR; however, 5 to 36% of field isolates were also positive for at least one of the alleles tested. A combination of PCR tests for vlhA3.04a, vlhA3.05, and mg0359 was able to distinguish the M. gallisepticum ts-11 vaccine <span class="hlt">strain</span> from field isolates. This method will further supplement current approaches to quickly distinguish M. gallisepticum vaccine <span class="hlt">strains</span> from field isolates. PMID:27847370</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('https://www.ncbi.nlm.nih.gov/pubmed/22043083','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22043083"><span><span class="hlt">Strain</span> Hardening and <span class="hlt">Strain</span> Softening of Reversibly Cross-linked Supramolecular Polymer Networks.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xu, Donghua; Craig, Stephen L</p> <p>2011-09-27</p> <p>The large amplitude oscillatory shear behavior of metallo-supramolecular polymer networks formed by adding bis-Pd(II) cross-linkers to poly(4-vinylpyridine) (PVP) in dimethyl sulfoxide (DMSO) solution is reported. The influence of scanning frequency, dissociation rate of cross-linkers, concentration of cross-linkers, and concentration of PVP solution on the large amplitude oscillatory shear behavior is explored. In semidilute unentangled PVP solutions, above a critical scanning frequency, <span class="hlt">strain</span> hardening of both storage moduli and loss moduli is observed. In the semidilute entangled regime of PVP solution, however, <span class="hlt">strain</span> softening is observed for samples with faster cross-linkers (k(d) ∼ 1450 s(-1)), whereas <span class="hlt">strain</span> hardening is observed for samples with slower cross-linkers (k(d) ∼ 17 s(-1)). The mechanism of <span class="hlt">strain</span> hardening is attributed primarily to a <span class="hlt">strain</span>-induced increase in the number of elastically active chains, with possible contributions from non-Gaussian stretching of polymer chains at <span class="hlt">strains</span> approaching network fracture. The divergent <span class="hlt">strain</span> softening of samples with faster cross-linkers in semidilute entangled PVP solutions, relative to the <span class="hlt">strain</span> hardening of samples with slower cross-linkers, is consistent with observed shear thinning/shear thickening behavior reported previously and is attributed to the fact that the average time that a cross-linker remains detached is too short to permit the local relaxation of polymer chain segments that is necessary for a net conversion of elastically inactive to elastically active cross-linkers. These and other observations paint a picture in which <span class="hlt">strain</span> softening and shear thinning arise from the same set of molecular mechanisms, conceptually uniting the two nonlinear responses for this system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MeScT..26e5103W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MeScT..26e5103W"><span>Network of flexible capacitive <span class="hlt">strain</span> gauges for the reconstruction of surface <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>Wu, Jingzhe; Song, Chunhui; Saleem, Hussam S.; Downey, Austin; Laflamme, Simon</p> <p>2015-05-01</p> <p>Monitoring of surface <span class="hlt">strain</span> on mesosurfaces is a difficult task, often impeded by the lack of scalability of conventional sensing systems. A solution is to deploy large networks of flexible <span class="hlt">strain</span> gauges, a type of large area electronics. The authors have recently proposed a soft elastomeric capacitor (SEC) as an economical skin-type solution for large-scale deployment onto mesosurfaces. The sensing principle is based on a measurable change in the sensor’s capacitance upon <span class="hlt">strain</span>. In this paper, we study the performance of the sensor at reconstructing surface <span class="hlt">strain</span> map and deflection shapes. A particular feature of the sensor is that it measures surface <span class="hlt">strain</span> additively, because it is not utilized within a Wheatstone bridge configuration. An algorithm is proposed to decompose the additive in-plane <span class="hlt">strain</span> measurements from the SEC into principal components. The algorithm consists of assuming a polynomial shape function, and deriving the <span class="hlt">strain</span> based on Kirchhoff plate theory. A least-squares estimator (LSE) is used to minimize the error between the assumed model and the SEC signals after the enforcement of boundary conditions. Numerical simulations are conducted on a symmetric rectangular cantilever thin plate under symmetric and asymmetric static loads to demonstrate the accuracy and real-time applicability of the algorithm. The performance of the algorithm is further examined on an asymmetric cantilever laminated thin plate constituted with orthotropic materials mimicking a wind turbine blade, and subjected to a non-stationary wind load. Results from simulations show good performance of the algorithm at reconstructing the surface <span class="hlt">strain</span> maps for both in-plane principal <span class="hlt">strain</span> components, and that it can be applied in real time. However, its performance can be improved by strengthening assumptions on boundary conditions. The algorithm exhibits robustness in performance with respect to load and noise in signals, except when most of the sensors’ signals are</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004PhST..114...22W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004PhST..114...22W"><span>Silicon Germanium <span class="hlt">Strained</span> Layers and Heterostructures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Willander, M.; Nur, O.; Jain, S. C.</p> <p>2004-01-01</p> <p>The integration of <span class="hlt">strained</span>-Si1 xGex into Si technology has enhanced the performance and extended the functionality of Si based circuits. The improvement of device performance is observed in both AC as well as DC characteristics of these devices. The category of such devices includes field effect as well as bipolar families. Speed performance in some based circuits has reached limits previously dominated by III-V heterostructures based devices. In addition, for some optoelectronics applications including photodetectors it is now possible to easily integrate <span class="hlt">strained</span>-Si1 xGex based optical devices into standard Silicon technology. The impact of integrating <span class="hlt">strained</span> and relaxed Si1 xGex alloys into Si technology is important. It has lead to stimulate Si research as well as offers easy options for performances that requires very complicated and costly process if pure Si has to be used. In this paper we start by discussing the <span class="hlt">strain</span> and stability of Si1 xGex alloys. The origin and the process responsible for transient enhanced diffusion (TED) in highly doped Si containing layers will be mentioned. Due to the importance of TED for thin highly doped Boron <span class="hlt">strained</span>-Si1 xGex layers and its degrading consequences, possible suppression design methods will be presented. Quantum well pchannel MOSFETs (QW-PMOSFETs) based on thin buried QW are solution to the low speed and weak current derivability. Different aspects of designing these devices for a better performance are briefly reviewed. Other FETs based on tensile <span class="hlt">strained</span> Si on relaxed Si1 xGex for n-channel and modulation doped field effect transistors (MODFETs) showed excellent performance. Record AC performance well above 200GHz for fmax is already observed and this record is expected to increase in the coming years. Heterojunction bipolar transistors (HPTs) with thin <span class="hlt">strained</span>-Si1 xGex highly doped base have lead to optimize the performance of the bipolar technology for many applications easily. The strategies of design</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160011958','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160011958"><span>Unsteady Aerodynamic Force 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>2016-01-01</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. A cantilevered rectangular wing built and tested at the NASA Langley Research Center (Hampton, Virginia, USA) in 1959 is used to validate the simple approach. Unsteady aerodynamic forces as well as wing deflections, velocities, accelerations, and <span class="hlt">strains</span> are computed using the CFL3D computational fluid dynamics (CFD) code and an MSC/NASTRAN code (MSC Software Corporation, Newport Beach, California, USA), and these CFL3D-based results are assumed as measured quantities. Based on the measured <span class="hlt">strains</span>, wing deflections, velocities, accelerations, and aerodynamic forces are computed using the proposed approach. These computed deflections, velocities, accelerations, and unsteady aerodynamic forces are compared with the CFL3D/NASTRAN-based results. In general, computed aerodynamic forces based on the lifting surface theory in subsonic speeds are in good agreement with the target aerodynamic forces generated using CFL3D code with the Euler equation. Excellent aeroelastic responses are obtained even with unsteady <span class="hlt">strain</span> data under the signal to noise ratio of -9.8dB. The deflections, velocities, and accelerations at each sensor location are independent of structural and aerodynamic models. Therefore, the distributed <span class="hlt">strain</span> data together with the current proposed approaches can be used as distributed deflection</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910064276&hterms=wire+resistance+temperature&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dwire%2Bresistance%2Btemperature','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910064276&hterms=wire+resistance+temperature&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dwire%2Bresistance%2Btemperature"><span>A resistance <span class="hlt">strain</span> gage with repeatable apparent <span class="hlt">strain</span> 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, J.-F.</p> <p>1991-01-01</p> <p>Experimental PdCr temperature-compensated resistance static-<span class="hlt">strain</span> gages are described. The gages are developed in both fine-wire and thin-film forms. It is found that a PdCr wire <span class="hlt">strain</span> gage coated with a flame-sprayed mixture of alumina and 4 wt pct zirconia demonstrates the smallest variation in and the best repeatability of apparent <span class="hlt">strain</span> among the existing gages used at temperatures up to 800 C. Results of preliminary tests indicate uncompensated uncoated thin-film gages have potential usefulness at temperatures up to 1000 C.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992ApOpt..31.2987F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992ApOpt..31.2987F"><span>Simultaneous interferometric and polarimetric <span class="hlt">strain</span> measurements on composites using a fiber-optic <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>Fuerstenau, N.; Schmidt, W.; Goetting, H.-C.</p> <p>1992-06-01</p> <p>A fiberoptic Michelson interferometer is used for remote sensing of the bending-induced surface <span class="hlt">strain</span> of plates made from carbon-fiber composites. The double-polarization method is used for eliminating the ambiguity of fringe counting. Simultaneous measurement of the birefringence-dependent phase offset yields an additional analog (polarimetric) signal, which allows for initialization of the incremental readout. The measured dependence of surface <span class="hlt">strain</span> on plate bending agrees with the theoretically expected linear relationship, and it agrees with the gauge sensitivity published by Valis et al. (1989). The observed hysteresis and temperature sensitivity are significantly smaller than the same effects in an electrical <span class="hlt">strain</span> gauge.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EPJWC..9404006H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EPJWC..9404006H"><span><span class="hlt">Strain</span> rate effects for spallation of concrete</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Häussler-Combe, Ulrich; Panteki, Evmorfia; Kühn, Tino</p> <p>2015-09-01</p> <p>Appropriate triaxial constitutive laws are the key for a realistic simulation of high speed dynamics of concrete. The <span class="hlt">strain</span> rate effect is still an open issue within this context. In particular the question whether it is a material property - which can be covered by rate dependent stress <span class="hlt">strain</span> relations - or mainly an effect of inertia is still under discussion. Experimental and theoretical investigations of spallation of concrete specimen in a Hopkinson Bar setup may bring some evidence into this question. For this purpose the paper describes the VERD model, a newly developed constitutive law for concrete based on a damage approach with included <span class="hlt">strain</span> rate effects [1]. In contrast to other approaches the dynamic strength increase is not directly coupled to <span class="hlt">strain</span> rate values but related to physical mechanisms like the retarded movement of water in capillary systems and delayed microcracking. The constitutive law is fully triaxial and implemented into explicit finite element codes for the investigation of a wide range of concrete structures exposed to impact and explosions. The current setup models spallation experiments with concrete specimen [2]. The results of such experiments are mainly related to the dynamic tensile strength and the crack energy of concrete which may be derived from, e.g., the velocity of spalled concrete fragments. The experimental results are compared to the VERD model and two further constitutive laws implemented in LS-Dyna. The results indicate that both viscosity and retarded damage are required for a realistic description of the material behaviour of concrete exposed to high <span class="hlt">strain</span> effects [3].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.G53C..02W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.G53C..02W"><span>Searching for <span class="hlt">Strain</span> Transients in PBO data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wei, M.; McGuire, J. J.; Richardson, E.; Kraft, R. L.; Hardwig, M. D.</p> <p>2011-12-01</p> <p>We applied a recently developed <span class="hlt">strain</span> anomaly detector, the Network Stain Filter [Ohtani et al., 2010], to the continuous GPS datasets from the PBO in Alaska and Salton Trough. The strategy of the filter is to find spatially and temporally coherent signals by processing data from the entire network simultaneously. Compared to previous Network Inversion Filter [Segall and Matthews, 1997], the new detector does not require the knowledge of potential sources, which can be either unknown and/or very numerous in a large tectonically active area. At Alaska, we find a <span class="hlt">strain</span> anomaly between Kodiak Island and Kenai Peninsula that began in early 2010. There are earthquakes that are likely related to the <span class="hlt">strain</span> anomaly. The physical interpretation of the <span class="hlt">strain</span> anomaly is still in progress. The secular motion since 2006 that PBO recorded is consistent with a model that consist of two locked patches on Kodiak Island and Kenai Peninsula and a creeping patch near Cook Inlet as determined earlier by Zweck et al. [2002]. Seasonal signals dominate in the data and are highly correlated between stations in the horizontal components. The reason for this correlation in seasonal term azimuths between stations is not clear. At Salton Trough, the post-seismic deformation of the 2010 Mw 7.2 El Mayor Earthquake dominates the transient signals. The maximum post-seismic slip recorded by the GPS is 23 mm during 1.5 years after the earthquake (Site ID P494). Additionally, we are exploring using InSAR data as a complimentary method for detecting <span class="hlt">strain</span> anomaly in areas with shallow sources, such as in the Salton Trough. A creep event on the Superstition Hills Fault in October 2006 has been observed by InSAR but missed by nearby GPS stations due to low amplitude at the location [Wei et al., 2009].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23575634','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23575634"><span>Unexpected <span class="hlt">strain</span>-stiffening in crystalline solids.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jiang, Chao; Srinivasan, Srivilliputhur G</p> <p>2013-04-18</p> <p><span class="hlt">Strain</span>-stiffening--an increase in material stiffness at large <span class="hlt">strains</span>--is a vital mechanism by which many soft biological materials thwart excessive deformation to protect tissue integrity. Understanding the fundamental science of <span class="hlt">strain</span>-stiffening and incorporating this concept into the design of metals and ceramics for advanced applications is an attractive prospect. Using cementite (Fe3C) and aluminium borocarbide (Al3BC3) as prototypes, here we show via quantum-mechanical calculations that <span class="hlt">strain</span>-stiffening also occurs, surprisingly, in simple inorganic crystalline solids and confers exceptionally high strengths to these two solids, which have anomalously low resistance to deformation near equilibrium. For Fe3C and Al3BC3, their ideal shear strength to shear modulus ratios attain remarkably high values of 1.14 and 1.34 along the (010)[001] and slip systems, respectively. These values are more than seven times larger than the original Frenkel value of 1/2π (refs 4, 5) and are the highest yet reported for crystalline solids. The extraordinary stiffening of Fe3C arises from the <span class="hlt">strain</span>-induced reversible 'cross-linking' between weakly coupled edge- and corner-sharing Fe6C slabs. This new bond formation creates a strong, three-dimensional covalent bond network that resists large shear deformation. Unlike Fe3C, no new bond forms in Al3BC3 but stiffening still occurs because strong repulsion between Al and B in a compressed Al-B bond unsettles the existing covalent bond network. These discoveries challenge the conventional wisdom that large shear modulus is a reliable predictor of hardness and strength of materials, and provide new lessons for materials selection and design.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21185052','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21185052"><span>Colloid <span class="hlt">straining</span> within saturated heterogeneous porous media.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Porubcan, Alexis A; Xu, Shangping</p> <p>2011-02-01</p> <p>The transport of 0.46 μm, 2.94 μm, 5.1 μm and 6.06 μm latex particles in heterogeneous porous media prepared from the mixing of 0.78 mm, 0.46 mm and 0.23 mm quartz sands was investigated through column transport experiments. It was observed that the 0.46 μm particles traveled conservatively within the heterogeneous porous media, suggesting that under the experimental conditions employed in this research the strong repulsive interactions between the negatively charged latex particles and the clean quartz sands led to minimal colloid immobilization due to physicochemical filtration. The immobilization of the 2.94 μm, 5.1 μm and 6.06 μm latex particles was thus attributed to colloid <span class="hlt">straining</span>. Experimental results showed that the <span class="hlt">straining</span> of colloidal particles within heterogeneous sand mixtures increased when the fraction of finer sands increased. The mathematical model that was developed and tested based on results obtained using uniform sands (Xu et al., 2006) was found to be able to describe colloid <span class="hlt">straining</span> within heterogeneous porous media. Examination of the relationship between the best-fit values of the clean-bed <span class="hlt">straining</span> rate coefficients (k(0)) and the ratio of colloid diameter (d(p)) and sand grain size (d(g)) indicated that when number-average sizes were used to represent the size of the heterogeneous porous media, there existed a consistent relationship for both uniform sands and heterogeneous sand mixtures. Similarly, the use of the number-averaged sizes for the heterogeneous porous media produced a uniform relationship between the colloid <span class="hlt">straining</span> capacity term (λ) and the ratio of d(p)/d(g) for all the sand treatments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18051229','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18051229"><span>[Behavior of Argentine lymphocytic choriomeningitis virus <span class="hlt">strains</span> in rodents].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Saavedra, María del Cármen; Ambrosio, Ana M; Riera, Laura; Sabattini, Marta S</p> <p>2007-01-01</p> <p>The activity of LCM virus was first reported in Argentina at the beginning of the seventies and only five <span class="hlt">strains</span> have been isolated from rodents Mus domesticus and two from humans. The objective of this paper was to find differential biological characteristics of Argentine <span class="hlt">strains</span> of LCM virus comparing them in relation to the historical <span class="hlt">strains</span> WE and Armstrong. Regarding the results obtained in tissue culture, when L 929 cells were used, plaque forming units (PFU) were obtained with human and mouse <span class="hlt">strains</span>, whilst on Vero cells only human <span class="hlt">strains</span> developed PFU. Differentials characteristics of historical and Argentine <span class="hlt">strain</span>'s plates were not found, neither differences related to the <span class="hlt">strain</span>'s origin. Neither historical nor Argentine <span class="hlt">strains</span> were lethal to new-born mice giving a persistent infection, that was demonstrated when we inoculated new-born mouse by intracranial route with different <span class="hlt">strains</span> of LCM virus and virus was isolated from brains harvested at different days post inoculation. The only exception was Cba An 13065 <span class="hlt">strain</span> that exhibited virulence in new-born mice, only with 0.026 PFU was obtained 1 DL50. All the <span class="hlt">strains</span> resulted lethal to adult mice. The mouse <span class="hlt">strains</span> were more virulent than human <span class="hlt">strains</span>, being Cba An 13065 the most virulent. These results demonstrate a different behavior in tissue culture between human and mouse <span class="hlt">strains</span> and allow the identification of virulence markers by intracranial inoculation into new-born or adult mice.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26968547','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26968547"><span>The influence of acute unloading on left ventricular <span class="hlt">strain</span> and <span class="hlt">strain</span> rate by speckle tracking echocardiography in a porcine model.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dahle, Geir Olav; Stangeland, Lodve; Moen, Christian Arvei; Salminen, Pirjo-Riitta; Haaverstad, Rune; Matre, Knut; Grong, Ketil</p> <p>2016-05-15</p> <p>Noninvasive measurements of myocardial <span class="hlt">strain</span> and <span class="hlt">strain</span> rate by speckle tracking echocardiography correlate to cardiac contractile state but also to load, which may weaken their value as indices of inotropy. In a porcine model, we investigated the influence of acute dynamic preload reductions on left ventricular <span class="hlt">strain</span> and <span class="hlt">strain</span> rate and their relation to the pressure-conductance catheter-derived preload recruitable stroke work (PRSW) and peak positive first derivative of left ventricular pressure (LV-dP/dtmax). Speckle tracking <span class="hlt">strain</span> and <span class="hlt">strain</span> rate in the longitudinal, circumferential, and radial directions were measured during acute dynamic reductions of end-diastolic volume during three different myocardial inotropic states. Both <span class="hlt">strain</span> and <span class="hlt">strain</span> rate were sensitive to unloading of the left ventricle (P < 0.001), but the load dependency for <span class="hlt">strain</span> rate was modest compared with <span class="hlt">strain</span>. Changes in longitudinal and circumferential <span class="hlt">strain</span> correlated more strongly to changes in end-diastolic volume (r = -0.86 and r = -0.72) than did radial <span class="hlt">strain</span> (r = 0.35). Longitudinal, circumferential, and radial <span class="hlt">strain</span> significantly correlated with LV-dP/dtmax (r = -0.53, r = -0.46, and r = 0.86), whereas only radial <span class="hlt">strain</span> correlated with PRSW (r = 0.55). <span class="hlt">Strain</span> rate in the longitudinal, circumferential and radial direction significantly correlated with both PRSW (r = -0.64, r = -0.58, and r = 0.74) and LV-dP/dtmax (r = -0.95, r = -0.70, and r = 0.85). In conclusion, the speckle tracking echocardiography-derived <span class="hlt">strain</span> rate is more robust to dynamic ventricular unloading than <span class="hlt">strain</span>. Longitudinal and circumferential <span class="hlt">strain</span> could not predict load-independent contractility. <span class="hlt">Strain</span> rates, and especially in the radial direction, are good predictors of preload-independent inotropic markers derived from conductance catheter.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5041503','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5041503"><span>Brucella abortus <span class="hlt">Strain</span> 2308 Wisconsin Genome: Importance of the Definition of Reference <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>Suárez-Esquivel, Marcela; Ruiz-Villalobos, Nazareth; Castillo-Zeledón, Amanda; Jiménez-Rojas, César; Roop II, R. Martin; Comerci, Diego J.; Barquero-Calvo, Elías; Chacón-Díaz, Carlos; Caswell, Clayton C.; Baker, Kate S.; Chaves-Olarte, Esteban; Thomson, Nicholas R.; Moreno, Edgardo; Letesson, Jean J.; De Bolle, Xavier; Guzmán-Verri, Caterina</p> <p>2016-01-01</p> <p>Brucellosis is a bacterial infectious disease affecting a wide range of mammals and a neglected zoonosis caused by species of the genetically homogenous genus Brucella. As in most studies on bacterial diseases, research in brucellosis is carried out by using reference <span class="hlt">strains</span> as canonical models to understand the mechanisms underlying host pathogen interactions. We performed whole genome sequencing analysis of the reference <span class="hlt">strain</span> B. abortus 2308 routinely used in our laboratory, including manual curated annotation accessible as an editable version through a link at https://en.wikipedia.org/wiki/Brucella#Genomics. Comparison of this genome with two publically available 2308 genomes showed significant differences, particularly indels related to insertional elements, suggesting variability related to the transposition of these elements within the same <span class="hlt">strain</span>. Considering the outcome of high resolution genomic techniques in the bacteriology field, the conventional concept of <span class="hlt">strain</span> definition needs to be revised. PMID:27746773</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20625472','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20625472"><span>Gendered Responses to Serious <span class="hlt">Strain</span>: The Argument for a General <span class="hlt">Strain</span> Theory of Deviance.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kaufman, Joanne M</p> <p>2009-09-01</p> <p>This paper expands and builds on newer avenues in research on gender and general <span class="hlt">strain</span> theory (GST). I accomplish this by focusing on serious <span class="hlt">strains</span> that are relevant for males and females, including externalizing and internalizing forms of negative emotions, and including multiple gendered deviant outcomes. Using the Add Health dataset, I find strong support for the impact of serious <span class="hlt">strains</span> on both types of negative emotions and different forms of deviance for males and females. However, the experience of serious <span class="hlt">strain</span>, emotionally and behaviorally, is gendered. Depressive symptoms are particularly important for all types of deviance by females. Including multiple types of deviant outcomes offers a fuller understanding of both similarities and differences by gender. These results support the utility of GST as a theory of deviance in general and support greater connections between GST, feminist theorizing, and the sociology of mental health.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27746773','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27746773"><span>Brucella abortus <span class="hlt">Strain</span> 2308 Wisconsin Genome: Importance of the Definition of Reference <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>Suárez-Esquivel, Marcela; Ruiz-Villalobos, Nazareth; Castillo-Zeledón, Amanda; Jiménez-Rojas, César; Roop Ii, R Martin; Comerci, Diego J; Barquero-Calvo, Elías; Chacón-Díaz, Carlos; Caswell, Clayton C; Baker, Kate S; Chaves-Olarte, Esteban; Thomson, Nicholas R; Moreno, Edgardo; Letesson, Jean J; De Bolle, Xavier; Guzmán-Verri, Caterina</p> <p>2016-01-01</p> <p>Brucellosis is a bacterial infectious disease affecting a wide range of mammals and a neglected zoonosis caused by species of the genetically homogenous genus Brucella. As in most studies on bacterial diseases, research in brucellosis is carried out by using reference <span class="hlt">strains</span> as canonical models to understand the mechanisms underlying host pathogen interactions. We performed whole genome sequencing analysis of the reference <span class="hlt">strain</span> B. abortus 2308 routinely used in our laboratory, including manual curated annotation accessible as an editable version through a link at https://en.wikipedia.org/wiki/Brucella#Genomics. Comparison of this genome with two publically available 2308 genomes showed significant differences, particularly indels related to insertional elements, suggesting variability related to the transposition of these elements within the same <span class="hlt">strain</span>. Considering the outcome of high resolution genomic techniques in the bacteriology field, the conventional concept of <span class="hlt">strain</span> definition needs to be revised.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3192842','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3192842"><span>A Wide Extent of Inter-<span class="hlt">Strain</span> Diversity in Virulent and Vaccine <span class="hlt">Strains</span> of Alphaherpesviruses</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Szpara, Moriah L.; Tafuri, Yolanda R.; Parsons, Lance; Shamim, S. Rafi; Verstrepen, Kevin J.; Legendre, Matthieu; Enquist, L. W.</p> <p>2011-01-01</p> <p>Alphaherpesviruses are widespread in the human population, and include herpes simplex virus 1 (HSV-1) and 2, and varicella zoster virus (VZV). These viral pathogens cause epithelial lesions, and then infect the nervous system to cause lifelong latency, reactivation, and spread. A related veterinary herpesvirus, pseudorabies (PRV), causes similar disease in livestock that result in significant economic losses. Vaccines developed for VZV and PRV serve as useful models for the development of an HSV-1 vaccine. We present full genome sequence comparisons of the PRV vaccine <span class="hlt">strain</span> Bartha, and two virulent PRV isolates, Kaplan and Becker. These genome sequences were determined by high-throughput sequencing and assembly, and present new insights into the attenuation of a mammalian alphaherpesvirus vaccine <span class="hlt">strain</span>. We find many previously unknown coding differences between PRV Bartha and the virulent <span class="hlt">strains</span>, including changes to the fusion proteins gH and gB, and over forty other viral proteins. Inter-<span class="hlt">strain</span> variation in PRV protein sequences is much closer to levels previously observed for HSV-1 than for the highly stable VZV proteome. Almost 20% of the PRV genome contains tandem short sequence repeats (SSRs), a class of nucleic acids motifs whose length-variation has been associated with changes in DNA binding site efficiency, transcriptional regulation, and protein interactions. We find SSRs throughout the herpesvirus family, and provide the first global characterization of SSRs in viruses, both within and between <span class="hlt">strains</span>. We find SSR length variation between different isolates of PRV and HSV-1, which may provide a new mechanism for phenotypic variation between <span class="hlt">strains</span>. Finally, we detected a small number of polymorphic bases within each plaque-purified PRV <span class="hlt">strain</span>, and we characterize the effect of passage and plaque-purification on these polymorphisms. These data add to growing evidence that even plaque-purified stocks of stable DNA viruses exhibit limited sequence</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930038316&hterms=wire+resistance+temperature&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dwire%2Bresistance%2Btemperature','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930038316&hterms=wire+resistance+temperature&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dwire%2Bresistance%2Btemperature"><span>High temperature static <span class="hlt">strain</span> measurement with an electrical resistance <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>Lei, Jih-Fen</p> <p>1992-01-01</p> <p>An electrical resistance <span class="hlt">strain</span> gage that can supply accurate static <span class="hlt">strain</span> measurement for NASP application is being developed both in thin film and fine wire forms. This gage is designed to compensate for temperature effects on substrate materials with a wide range of thermal expansion coefficients. Some experimental results of the wire gage tested on one of the NASP structure materials, i.e., titanium matrix composites, are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4445032','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4445032"><span>The genome of Shigella dysenteriae <span class="hlt">strain</span> Sd1617 comparison to representative <span class="hlt">strains</span> in evaluating pathogenesis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Vongsawan, Ajchara A.; Kapatral, Vinayak; Vaisvil, Benjamin; Burd, Henry; Serichantalergs, Oralak; Venkatesan, Malabi M.; Mason, Carl J.</p> <p>2015-01-01</p> <p>We sequenced and analyzed Shigella dysenteriae <span class="hlt">strain</span> Sd1617 serotype 1 that is widely used as model <span class="hlt">strain</span> for vaccine design, trials and research. A combination of next-generation sequencing platforms and assembly yielded two contigs representing a chromosome size of 4.34 Mb and the large virulence plasmid of 177 kb. This genome sequence is compared with other Shigella genomes in order to understand gene complexity and pathogenic factors. PMID:25743074</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EPJB...89..227S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EPJB...89..227S"><span>Effects of <span class="hlt">strain</span> on shot noise properties in graphene superlattices</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sattari, Farhad; Mirershadi, Soghra</p> <p>2016-10-01</p> <p>In this paper the transmission and the shot noise properties through the <span class="hlt">strain</span>-induced graphene superlattices are studied. It is found that for the zigzag direction <span class="hlt">strain</span> the Fano factor shows a peak at new Dirac-like point and the position of the new Dirac point varies against the <span class="hlt">strain</span>. Also, Fano factor has an oscillatory behavior with respect to <span class="hlt">strain</span> strength and the oscillation period decreases by increasing the number of barriers. However, for the armchair direction <span class="hlt">strain</span> the transmission can be blocked by the electric barrier and the Fano factor approaches 1, this is different from the zigzag direction <span class="hlt">strain</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MSSP...60..485P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MSSP...60..485P"><span>Generating <span class="hlt">strain</span> signals under consideration of road surface profiles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Putra, T. E.; Abdullah, S.; Schramm, D.; Nuawi, M. Z.; Bruckmann, T.</p> <p>2015-08-01</p> <p>The current study aimed to develop the mechanism for generating <span class="hlt">strain</span> signal utilising computer-based simulation. The <span class="hlt">strain</span> data, caused by the acceleration, were undertaken from a fatigue data acquisition involving car movements. Using a mathematical model, the measured <span class="hlt">strain</span> signals yielded to acceleration data used to describe the bumpiness of road surfaces. The acceleration signals were considered as an external disturbance on generating <span class="hlt">strain</span> signals. Based on this comparison, both the actual and simulated <span class="hlt">strain</span> data have similar pattern. The results are expected to provide new knowledge to generate a <span class="hlt">strain</span> signal via a simulation.</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><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><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. 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