Science.gov

Sample records for actinobacterium designated strain

  1. Draft Genome Sequence of Frankia sp. Strain BMG5.12, a Nitrogen-Fixing Actinobacterium Isolated from Tunisian Soils

    PubMed Central

    Nouioui, Imen; Beauchemin, Nicholas; Cantor, Michael N.; Chen, Amy; Detter, J. Chris; Furnholm, Teal; Ghodhbane-Gtari, Faten; Goodwin, Lynne; Gtari, Maher; Han, Cliff; Han, James; Huntemann, Marcel; Hua, Susan Xinyu; Ivanova, Natalia; Kyrpides, Nikos; Markowitz, Victor; Mavrommatis, Kostas; Mikhailova, Natalia; Nordberg, Henrik P.; Ovchinnikova, Galina; Pagani, Ioanna; Pati, Amrita; Sen, Arnab; Sur, Saubashya; Szeto, Ernest; Thakur, Subarna; Wall, Luis; Wei, Chia-Lin; Woyke, Tanja

    2013-01-01

    Members of the actinomycete genus Frankia form a nitrogen-fixing symbiosis with 8 different families of actinorhizal plants. We report a draft genome sequence for Frankia sp. strain BMG5.12, a nitrogen-fixing actinobacterium isolated from Tunisian soils with the ability to infect Elaeagnus angustifolia and Myrica gale. PMID:23846272

  2. Draft Genome Sequence of Frankia sp. Strain BCU110501, a Nitrogen-Fixing Actinobacterium Isolated from Nodules of Discaria trinevis

    PubMed Central

    Wall, Luis G.; Beauchemin, Nicholas; Cantor, Michael N.; Chaia, Eugenia; Chen, Amy; Detter, J. Chris; Furnholm, Teal; Ghodhbane-Gtari, Faten; Goodwin, Lynne; Gtari, Maher; Han, Cliff; Han, James; Huntemann, Marcel; Hua, Susan Xinyu; Ivanova, Natalia; Kyrpides, Nikos; Markowitz, Victor; Mavrommatis, Kostas; Mikhailova, Natalia; Nordberg, Henrik P.; Nouioui, Imen; Ovchinnikova, Galina; Pagani, Ioanna; Pati, Amrita; Sen, Arnab; Sur, Saubashya; Szeto, Ernest; Thakur, Subarna; Wei, Chia-Lin; Woyke, Tanja

    2013-01-01

    Frankia forms a nitrogen-fixing symbiosis with actinorhizal plants. We report a draft genome sequence for Frankia sp. strain BCU110501, a nitrogen-fixing actinobacterium isolated from nodules of Discaria trinevis grown in the Patagonia region of Argentina. PMID:23846281

  3. Draft Genome Sequence of Frankia sp. Strain BMG5.12, a Nitrogen-Fixing Actinobacterium Isolated from Tunisian Soils.

    PubMed

    Nouioui, Imen; Beauchemin, Nicholas; Cantor, Michael N; Chen, Amy; Detter, J Chris; Furnholm, Teal; Ghodhbane-Gtari, Faten; Goodwin, Lynne; Gtari, Maher; Han, Cliff; Han, James; Huntemann, Marcel; Hua, Susan Xinyu; Ivanova, Natalia; Kyrpides, Nikos; Markowitz, Victor; Mavrommatis, Kostas; Mikhailova, Natalia; Nordberg, Henrik P; Ovchinnikova, Galina; Pagani, Ioanna; Pati, Amrita; Sen, Arnab; Sur, Saubashya; Szeto, Ernest; Thakur, Subarna; Wall, Luis; Wei, Chia-Lin; Woyke, Tanja; Tisa, Louis S

    2013-07-11

    Members of the actinomycete genus Frankia form a nitrogen-fixing symbiosis with 8 different families of actinorhizal plants. We report a draft genome sequence for Frankia sp. strain BMG5.12, a nitrogen-fixing actinobacterium isolated from Tunisian soils with the ability to infect Elaeagnus angustifolia and Myrica gale.

  4. Draft Genome Sequence of Microbacterium sp. Strain Alg239_V18, an Actinobacterium Retrieved from the Marine Sponge Spongia sp.

    PubMed Central

    Karimi, Elham; Gonçalves, Jorge M. S.; Reis, Margarida

    2017-01-01

    ABSTRACT Here, we describe the draft genome sequence of Microbacterium sp. strain Alg239_V18, an actinobacterium retrieved from the marine sponge Spongia sp. Genome annotation revealed a vast gene repertoire involved in antibiotic and heavy metal-resistance, and a versatile carbohydrate assimilation metabolism with potential for chitin utilization. PMID:28104653

  5. Draft Genome Sequence of Microbacterium sp. Strain Alg239_V18, an Actinobacterium Retrieved from the Marine Sponge Spongia sp.

    PubMed

    Karimi, Elham; Gonçalves, Jorge M S; Reis, Margarida; Costa, Rodrigo

    2017-01-19

    Here, we describe the draft genome sequence of Microbacterium sp. strain Alg239_V18, an actinobacterium retrieved from the marine sponge Spongia sp. Genome annotation revealed a vast gene repertoire involved in antibiotic and heavy metal-resistance, and a versatile carbohydrate assimilation metabolism with potential for chitin utilization.

  6. Insertion sequence content reflects genome plasticity in strains of the root nodule actinobacterium Frankia

    PubMed Central

    Bickhart, Derek M; Gogarten, Johann P; Lapierre, Pascal; Tisa, Louis S; Normand, Philippe; Benson, David R

    2009-01-01

    Background Genome analysis of three Frankia sp. strains has revealed a high number of transposable elements in two of the strains. Twelve out of the 20 major families of bacterial Insertion Sequence (IS) elements are represented in the 148 annotated transposases of Frankia strain HFPCcI3 (CcI3) comprising 3% of its total coding sequences (CDS). EAN1pec (EAN) has 183 transposase ORFs from 13 IS families comprising 2.2% of its CDS. Strain ACN14a (ACN) differs significantly from the other strains with only 33 transposase ORFs (0.5% of the total CDS) from 9 IS families. Results Insertion sequences in the Frankia genomes were analyzed using BLAST searches, PHYML phylogenies and the IRF (Inverted Repeat Finder) algorithms. To identify putative or decaying IS elements, a PSI-TBLASTN search was performed on all three genomes, identifying 36%, 39% and 12% additional putative transposase ORFs than originally annotated in strains CcI3, EAN and ACN, respectively. The distribution of transposase ORFs in each strain was then analysed using a sliding window, revealing significant clustering of elements in regions of the EAN and CcI3 genomes. Lastly the three genomes were aligned with the MAUVE multiple genome alignment tool, revealing several Large Chromosome Rearrangement (LCR) events; many of which correlate to transposase clusters. Conclusion Analysis of transposase ORFs in Frankia sp. revealed low inter-strain diversity of transposases, suggesting that the majority of transposase proliferation occurred without recent horizontal transfer of novel mobile elements from outside the genus. Exceptions to this include representatives from the IS3 family in strain EAN and seven IS4 transposases in all three strains that have a lower G+C content, suggesting recent horizontal transfer. The clustering of transposase ORFs near LCRs revealed a tendency for IS elements to be associated with regions of chromosome instability in the three strains. The results of this study suggest that IS

  7. Draft Genome Sequence of Kocuria rhizophila strain TPW45, an Actinobacterium Isolated from Freshwater

    PubMed Central

    Adrian, Tan-Guan-Sheng; Tan, Pui-Wan; Chen, Jian-Woon; Yin, Wai-Fong; Chan, Kok-Gan

    2016-01-01

    Kocuria rhizophila is a ubiquitous bacterium which is well known for its industrial value. Here, we present the draft genome of Kocuria rhizophila strain TPW45 which was isolated from Sungai Gabai, Selangor, Malaysia. The assembled genome comprised of 46 contigs and the estimated genome size is 2.7 Mb. Based on the RAST annotation, a gene cluster responsible for aromatic compound degradation was identified in this strain. PMID:27326264

  8. Draft Genome Sequence of Kocuria rhizophila strain TPW45, an Actinobacterium Isolated from Freshwater.

    PubMed

    Adrian, Tan-Guan-Sheng; Tan, Pui-Wan; Chen, Jian-Woon; Yin, Wai-Fong; Chan, Kok-Gan

    2016-01-01

    Kocuria rhizophila is a ubiquitous bacterium which is well known for its industrial value. Here, we present the draft genome of Kocuria rhizophila strain TPW45 which was isolated from Sungai Gabai, Selangor, Malaysia. The assembled genome comprised of 46 contigs and the estimated genome size is 2.7 Mb. Based on the RAST annotation, a gene cluster responsible for aromatic compound degradation was identified in this strain.

  9. Genomic analysis of a freshwater actinobacterium, "Candidatus Limnosphaera aquatica" strain IMCC26207, isolated from Lake Soyang.

    PubMed

    Kim, Suhyun; Kang, Ilnam; Cho, Jang-Cheon

    2017-02-07

    Strain IMCC26207 was isolated from the surface layer of Lake Soyang in Korea by the dilution-to-extinction culturing method using a liquid medium prepared with filtered and autoclaved lake water. The strain could neither be maintained in a synthetic medium other than natural freshwater medium nor grow on solid agar plates. Phylogenetic analysis of 16S rRNA gene sequences indicated that strain IMCC26207 formed a distinct lineage in the order Acidimicrobiales of the phylum Actinobacteria. The closest relative among the previously identified bacterial taxa was "Candidatus Microthrix parvicella" with 16S rRNA gene sequence similarity of 91.7%. Here the draft genome sequence of strain IMCC26207, a non-colony forming bacterium, is reported with the description of the genome properties and annotation summary. The draft genome consisted of 10 contigs with a total size of 3,316,799 bp and an average G+C content of 57.3%. The IMCC26207 genome was predicted to contain 2,975 protein-coding genes and 51 RNA genes, including 45 tRNA genes. Approximately 76% of the protein coding genes could be assigned with a specific function. Annotation of the IMCC26207 genome showed several traits of adaptation to living in oligotrophic freshwater environments such as phosphorus-limited condition. Comparative genomic analysis revealed that the genome of strain IMCC26207 was distinct from that of "Candidatus Microthrix" strains; therefore, we propose the name "Candidatus Limnosphaera aquatica" for this bacterium.

  10. Genome sequence of the Fleming strain of Micrococcus luteus, a simple free- living actinobacterium

    SciTech Connect

    Young, Michael; Artsatbanov, Vladislav; Beller, Harry R.; Chandra, Govind; Chater, Keith F.; Dover, Lynn G.; Goh, Ee-Been; Kahan, Tamar; Kaprelyants, Arseny S.; Kyrpides, Nikos; Lapidus, Alla; Lowry, Stephen R.; Lykidis, Athanasios; Mahillon, Jacques; Markowitz, Viktor; Mavrommatis, Konstantinos; Mukamolova, Galina V.; Oren, Aharon; Rokem, J. Stefan; Smith, Margaret C. M.; Young, Danielle I.; Greenblatt, Charles L.

    2009-11-01

    Micrococcus luteus (NCTC2665, Fleming strain) has one of the smallest genomes of free living actinobacteria sequenced to date, comprising a single circular chromosome of 2,501,097 bp (G+C content 73%) predicted to encode 2403 proteins. The genome shows extensive synteny with that of the closely related organism, Kocuria rhizophila, from which it was taxonomically separated relatively recently. Despite its small size, the genome harbors 73 IS elements, almost all of which are closely related to elements found in other actinobacteria. An IS element is inserted into the rrs gene of one of only two rrn operons found in M. luteus. The genome encodes only four sigma factors and fourteen response regulators, indicative of adaptation to a rather strict ecological niche (mammalian skin). The high sensitivity of M. luteus to {Beta}-lactam antibiotics may result from the presence of a reduced set of penicillin binding proteins and the absence of a wblC gene, which plays an important role in antibiotic resistance in other actinobacteria. Consistent with the restricted range of compounds it can use as a sole source of carbon for energy and growth, M. luteus has a minimal complement of genes concerned with carbohydrate transport and metabolism and its inability to utilize glucose as a sole carbon source may be due to the apparent absence of a gene encoding glucokinase. Uniquely among characterized bacteria, M. luteus appears to be able to metabolize glycogen only via trehalose, and to make trehalose only via glycogen. It has very few genes associated with secondary metabolism. In contrast to other actinobacteria, M. luteus encodes only one resuscitation-promoting factor (Rpf) required for emergence from dormancy and its complement of other dormancy-related proteins is also much reduced. M. luteus is capable of long-chain alkene biosynthesis, which is of interest for advanced biofuel production; a three gene cluster essential for this metabolism has been identified in the genome.

  11. Genome sequence of the Fleming strain of Micrococcus luteus, a simple free-living actinobacterium.

    PubMed

    Young, Michael; Artsatbanov, Vladislav; Beller, Harry R; Chandra, Govind; Chater, Keith F; Dover, Lynn G; Goh, Ee-Been; Kahan, Tamar; Kaprelyants, Arseny S; Kyrpides, Nikos; Lapidus, Alla; Lowry, Stephen R; Lykidis, Athanasios; Mahillon, Jacques; Markowitz, Victor; Mavromatis, Konstantinos; Mukamolova, Galina V; Oren, Aharon; Rokem, J Stefan; Smith, Margaret C M; Young, Danielle I; Greenblatt, Charles L

    2010-02-01

    Micrococcus luteus (NCTC2665, "Fleming strain") has one of the smallest genomes of free-living actinobacteria sequenced to date, comprising a single circular chromosome of 2,501,097 bp (G+C content, 73%) predicted to encode 2,403 proteins. The genome shows extensive synteny with that of the closely related organism, Kocuria rhizophila, from which it was taxonomically separated relatively recently. Despite its small size, the genome harbors 73 insertion sequence (IS) elements, almost all of which are closely related to elements found in other actinobacteria. An IS element is inserted into the rrs gene of one of only two rrn operons found in M. luteus. The genome encodes only four sigma factors and 14 response regulators, a finding indicative of adaptation to a rather strict ecological niche (mammalian skin). The high sensitivity of M. luteus to beta-lactam antibiotics may result from the presence of a reduced set of penicillin-binding proteins and the absence of a wblC gene, which plays an important role in the antibiotic resistance in other actinobacteria. Consistent with the restricted range of compounds it can use as a sole source of carbon for energy and growth, M. luteus has a minimal complement of genes concerned with carbohydrate transport and metabolism and its inability to utilize glucose as a sole carbon source may be due to the apparent absence of a gene encoding glucokinase. Uniquely among characterized bacteria, M. luteus appears to be able to metabolize glycogen only via trehalose and to make trehalose only via glycogen. It has very few genes associated with secondary metabolism. In contrast to most other actinobacteria, M. luteus encodes only one resuscitation-promoting factor (Rpf) required for emergence from dormancy, and its complement of other dormancy-related proteins is also much reduced. M. luteus is capable of long-chain alkene biosynthesis, which is of interest for advanced biofuel production; a three-gene cluster essential for this

  12. Draft Genome sequence of Frankia sp. Strain QA3, a nitrogen-fixing actinobacterium isolated from the root nodule of Alnus nitida

    SciTech Connect

    Sen, Arnab; Beauchemin, Nicholas; Bruce, David; Chain, Patrick S. G.; Chen, Amy; Davenport, Karen W.; Deshpande, Shweta; Detter, J. Chris; Furnholm, Teal; Ghodhbane-Gtari, Faten; Goodwin, Lynne A.; Gtari, Maher; Han, James; Huntemann, Marcel; Ivanova, N; Kyrpides, Nikos C; Land, Miriam L; Markowitz, Victor; Mavromatis, K; Nolan, Matt; Nouioui, Imen; Pagani, Ioanna; Pati, Amrita; Pitluck, Sam; Santos, Catarina; Sur, Saubashya; Szeto, Ernest; Tavares, Fernando; Teshima, Hazuki; Thakur, Subarna; Wall, Luis; Woyke, Tanja; Wishart, Jessie; Tisa, Louis S.

    2013-01-01

    Members of actinomycete genus Frankia form a nitrogen-fixing symbiosis with 8 different families of actinorhizal plants. We report a high-quality draft genome sequence for Frankia sp. stain QA3, a nitrogen-fixing actinobacterium isolated from root nodules of Alnus nitida.

  13. High quality draft genome of Nakamurella lactea type strain, a rock actinobacterium, and emended description of Nakamurella lactea.

    PubMed

    Nouioui, Imen; Göker, Markus; Carro, Lorena; Montero-Calasanz, Maria Del Carmen; Rohde, Manfred; Woyke, Tanja; Kyrpides, Nikos C; Klenk, Hans-Peter

    2017-01-01

    Nakamurella lactea DLS-10(T), isolated from rock in Korea, is one of the four type strains of the genus Nakamurella. In this study, we describe the high quality draft genome of N. lactea DLS-10(T) and its annotation. A summary of phenotypic data collected from previously published studies was also included. The genome of strain DLS-10(T) presents a size of 5.82 Mpb, 5100 protein coding genes, and a C + G content of 68.9%. Based on the genome analysis, emended description of N. lactea in terms of G + C content was also proposed.

  14. Streptosporangium saharense sp. nov., an actinobacterium isolated from Saharan soil.

    PubMed

    Chaabane Chaouch, Fawzia; Bouras, Noureddine; Mokrane, Salim; Zitouni, Abdelghani; Schumann, Peter; Spröer, Cathrin; Sabaou, Nasserdine; Klenk, Hans-Peter

    2016-03-01

    A novel actinobacterium, designated strain SG20T, was isolated from a Saharan soil sample collected from Béni-isguen (Mzab), Ghardaïa province, southern Algeria. The micro-organism developed small roundish sporangia on aerial mycelium that were sessile or carried by very short sporangiophores. The cell-wall peptidoglycan contained meso-diaminopimelic acid and the whole-cell sugars comprised glucose, ribose and mannose, but madurose was not detected. The predominant menaquinones were MK-9(H4), MK-9(H6) and MK-9(H2). The major fatty acids were iso-C16 : 0 and C16 : 0. The phospholipids detected were diphosphatidylglycerol, phosphatidylinositol, phosphatidylethanolamine and unknown lipids. The phenotypic and chemotaxonomic characteristics of the novel strain resembled those of recognized members of the genus Streptosporangium. Moreover, phylogenetic analysis based on a 16S rRNA gene sequence generated from the strain identified its closest relative as Streptosporangium jomthongense BCC 53154T (98.5 % similarity), which produces single spores on aerial mycelium, but no sporangia. In hybridization experiments, the DNA-DNA relatedness values recorded between strain SG20T and S. jomthongense DSM 46822T fell well below 70 %. On the basis of phenotypic and genotypic data, strain SG20T can be distinguished as representing a novel species of the genus Streptosporangium, for which the name Streptosporangium saharense sp. nov. is proposed. The type strain is SG20T ( = DSM 46743T = CECT 8840T).

  15. Cellulosimicrobium marinum sp. nov., an actinobacterium isolated from sea sediment.

    PubMed

    Hamada, Moriyuki; Shibata, Chiyo; Tamura, Tomohiko; Nurkanto, Arif; Ratnakomala, Shanti; Lisdiyanti, Puspita; Suzuki, Ken-Ichiro

    2016-07-01

    A novel Gram stain positive actinobacterium, designated RS-7-4(T), was isolated from a sea sediment sample collected in Indonesia, and its taxonomic position was investigated using a polyphasic approach. Strain RS-7-4(T) was observed to form vegetative hyphae in the early phase of growth, but the hyphae eventually fragmented into short rods to coccoid cells. Growth occurred at 15-37 °C, pH 6.0-11.0 and in the presence of 0-7 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain RS-7-4(T) was closely related to the members of the genus Cellulosimicrobium, with a similarity range of 98.08-99.10 %. The peptidoglycan type of strain RS-7-4(T) was found to be A4α L-Lys-L-Thr-D-Asp. The predominant menaquinone was MK-9(H4), and the major fatty acids were anteiso-C15:0, iso-C15:0 and anteiso-C17:0. The DNA G+C content was 75.6 mol%. These chemotaxonomic features corresponded to those of the genus Cellulosimicrobium. Meanwhile, the results of DNA-DNA hybridization, and physiological and biochemical tests revealed that strain RS-7-4(T) was different from the recognized species of the genus Cellulosimicrobium. Therefore, strain RS-7-4(T) represents a novel species of the genus Cellulosimicrobium, for which the name Cellulosimicrobium marinum sp. nov. is proposed. The type strain is RS-7-4(T) (=NBRC 110994(T) =InaCC A726(T)).

  16. Flindersiella endophytica gen. nov., sp. nov., an endophytic actinobacterium isolated from the root of Grey Box, an endemic eucalyptus tree.

    PubMed

    Kaewkla, Onuma; Franco, Christopher M M

    2011-09-01

    A novel endophytic actinobacterium, designated strain EUM 378(T), was isolated from the surface-sterilized root tissue of Eucalyptus microcarpa, a eucalyptus tree known as Grey Box. Phylogenetic evaluation based on 16S rRNA gene sequence analysis, including alignment with taxon-specific 16S rRNA gene signature nucleotides, placed this isolate as a member of the family Nocardioidaceae. Strain EUM 378(T) showed >5.5 % 16S rRNA gene sequence divergence from other members of this family and was related most closely to Actinopolymorpha alba YIM 48868(T) (94.2 %) and Actinopolymorpha singaporensis IM 7744(T) (94.4 %). This Gram-positive, aerobic actinobacterium has well-developed substrate mycelia that fragment into small rods. Chemotaxonomic data revealed that the cell wall contains LL-diaminopimelic acid, ribose, glucose and rhamnose. MK-10(H₆) is the predominant menaquinone. Chemotaxonomic and phylogenetic evidence confirmed that strain EUM 378(T) represents a novel species of a new genus, for which the name Flindersiella endophytica gen. nov., sp. nov. is proposed. The type strain is EUM 378(T) ( = DSM 45355(T) = ACM 5289(T)).

  17. Plantactinospora sonchi sp. nov., an actinobacterium isolated from the leaves of common sowthistle (Sonchus oleraceus L.).

    PubMed

    Ma, Zhaoxu; Liu, Chongxi; Fan, Jianlong; He, Hairong; Li, Chuang; Li, Jiansong; Zhao, Shanshan; Xiang, Wensheng; Wang, Xiangjing

    2015-12-01

    A novel actinobacterium, designated strain NEAU-QY2T, was isolated from the leaves of Sonchus oleraceus L. specimen, collected from Wuchang, Heilongjiang Province, China. A polyphasic study was carried out to establish the taxonomic position of this strain. The organism formed single spores with rough surfaces on substrate mycelia. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NEAU-QY2T belonged to the genus Plantactinospora and formed a monophyletic clade with its closest related strains Plantactinospora endophytica YIM 68255T (99.2 % 16S rRNA gene sequence similarity), Plantactinospora veratri NEAU-FHS4T (98.8 %) and Plantactinospora mayteni YIM 61359T(98.7 %), an association that was supported by a bootstrap value of 90 % in the neighbor-joining tree and also recovered with the maximum-likelihood algorithm. However, DNA-DNA hybridization values between strain NEAU-QY2T and the three closely related strains were below 70 %. With reference to phenotypic characteristics, phylogenetic data and DNA-DNA hybridization results, strain NEAU-QY2T was distinguished from closely related strains and is classified as representing a novel species of the genus Plantactinospora, for which the name Plantactinospora sonchi sp. nov. is proposed. The type strain is NEAU-QY2T (=CGMCC4.7216T=JCM 30345T).

  18. Prauserella endophytica sp. nov., an endophytic actinobacterium isolated from Tamarix taklamakanensis.

    PubMed

    Liu, Jia-Meng; Habden, Xugela; Guo, Lin; Tuo, Li; Jiang, Zhong-Ke; Liu, Shao-Wei; Liu, Xian-Fu; Chen, Li; Li, Rong-Feng; Zhang, Yu-Qin; Sun, Cheng-Hang

    2015-06-01

    A novel endophytic actinobacterium, designated strain SP28S-3(T), was isolated from a surface-sterilized stem of Tamarix taklamakanensis collected from the southern edge of Taklamakan desert, Xinjiang, China. Strain SP28S-3(T) was found to show chemotaxonomic and morphological properties consistent with its classification in the genus Prauserella. The polar lipids were found to consist of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphoglycolipid, phosphatidylcholine, phosphatidylinositol, a glycolipid, an aminolipid and unidentified phospholipids. The major fatty acids (>10 %) were identified as iso-C16:0 and C16:0. The genomic DNA G+C content was determined to be 69.7 mol%. Phylogenetic analysis of strain SP28S-3(T) clearly showed that the strain had the highest similarity of 16S rRNA gene sequence with Prauserella coralliicola SCSIO 11529(T) (99.9 %), followed by Prauserella marina DSM 45268(T) (97.0 %) and is affiliated with the genus Prauserella. The low level (47.8 ± 5.5 %) of DNA-DNA relatedness between strain SP28S-3(T) and P. coralliicola SCSIO 11529(T) combined with other polyphasic taxonomic evidence clearly support the conclusion that strain SP28S-3(T) represents a novel Prauserella species, for which the name Prauserella endophytica sp. nov. is proposed. The type strain is SP28S-3(T) (=DSM 46655(T) = CGMCC 4.7182 (T)).

  19. Modestobacter lacusdianchii sp. nov., a Phosphate-Solubilizing Actinobacterium with Ability to Promote Microcystis Growth

    PubMed Central

    Cheng, Juan; Li, Han-Quan; Yang, Jian-Yuan; Zha, Dai-Ming; Zhang, Yu-Qin; Ai, Meng-Jie; Hozzein, Wael N.; Li, Wen-Jun

    2016-01-01

    A novel actinobacterium, designated strain JXJ CY 19T, was isolated from a culture mat of Microcystis aeruginosa FACHB-905 collected from Dianchi Lake, South-west China. 16S rRNA gene sequences comparison of strain JXJ CY 19T and the available sequences in the GenBank database showed that the strain was closely related to Modestobacter marinus 42H12-1T (99.1% similarity) and Modestobacter roseus KLBMP 1279T (99.0%). The isolate had meso-diaminopimelic in the cell wall with whole-cell sugars of mannose, rhamnose, ribose, glucose, galactose, and arabinose. The menaquinone detected was MK-9(H4), while the major cellular fatty acids include C17:1 ω8c, C15:0 iso, C15:1 iso G and C16:0 iso. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside and an unidentified phospholipid. The DNA-DNA hybridization values between strains JXJ CY 19T and the closely related type strains Modestobacter marinus CGMCC 4.5581T and Modestobacter roseus NBRC 108673T were determined to be 50.8 ± 0.8% and 44.1 ± 1.7%, respectively. The DNA G+C content was 71.9 mol%. On the basis of the above taxonomic data and differences in physiological characters from the closely related type strains, strain JXJ CY 19T was recognized as a novel species of the genus Modestobacter, for which the name Modestobacter lacusdianchii sp. nov. (JXJ CY 19T = KCTC 39600T = CPCC 204352T) is proposed. The type strain JXJ CY 19T can solubilize calcium phosphate tribasic (Ca3(PO4)2), phytin and L-α-phosphatidylcholine. The phosphate-solubilizing property of the novel actinobacterium could be a possible factor for the increase in growth of Microcystis aeruginosa FACHB-905 in ecosystem where the amount of available soluble phosphate is limited such as Dianchi Lake. PMID:27537546

  20. Permanent Draft Genome Sequence of Nocardia sp. BMG111209, an Actinobacterium Isolated from Nodules of Casuarina glauca

    PubMed Central

    Ghodhbane-Gtari, Faten; Beauchemin, Nicholas; Gueddou, Abdellatif; Hezbri, Karima; Ktari, Amir; Louati, Moussa; Nouioui, Imen; Chen, Amy; Huntemann, Marcel; Ivanova, Natalia; Kyrpides, Nikos; Markowitz, Victor; Mavrommatis, Kostas; Pagani, Ioanna; Sen, Arnab; Wall, Luis; Woyke, Tanja

    2016-01-01

    Nocardia sp. strain BMG111209 is a non-Frankia actinobacterium isolated from root nodules of Casuarina glauca in Tunisia. Here, we report the 9.1-Mbp draft genome sequence of Nocardia sp. strain BMG111209 with a G + C content of 69.19% and 8,122 candidate protein-encoding genes. PMID:27491997

  1. Permanent Draft Genome Sequence of Nocardia sp. BMG111209, an Actinobacterium Isolated from Nodules of Casuarina glauca.

    PubMed

    Ghodhbane-Gtari, Faten; Beauchemin, Nicholas; Gueddou, Abdellatif; Hezbri, Karima; Ktari, Amir; Louati, Moussa; Nouioui, Imen; Chen, Amy; Huntemann, Marcel; Ivanova, Natalia; Kyrpides, Nikos; Markowitz, Victor; Mavrommatis, Kostas; Pagani, Ioanna; Sen, Arnab; Wall, Luis; Woyke, Tanja; Gtari, Maher; Tisa, Louis S

    2016-08-04

    Nocardia sp. strain BMG111209 is a non-Frankia actinobacterium isolated from root nodules of Casuarina glauca in Tunisia. Here, we report the 9.1-Mbp draft genome sequence of Nocardia sp. strain BMG111209 with a G + C content of 69.19% and 8,122 candidate protein-encoding genes.

  2. Permanent Draft Genome Sequence of Frankia sp. Strain Allo2, a Salt-Tolerant Nitrogen-Fixing Actinobacterium Isolated from the Root Nodules of Allocasuarina

    PubMed Central

    Oshone, Rediet; Ngom, Mariama; Abebe-Akele, Feseha; Simpson, Stephen; Morris, Krystalynne; Sy, Mame Ourèye; Champion, Antony; Thomas, W. Kelley

    2016-01-01

    Frankia sp. strain Allo2 is a member of Frankia lineage Ib, which is able to reinfect plants of the Casuarinaceae family, and exhibits a high level of salt tolerance compared to other isolates. Here, we report the 5.3-Mbp draft genome sequence of Frankia sp. strain Allo2 with a G+C content of 70.0% and 4,224 candidate protein-encoding genes. PMID:27198023

  3. Permanent Draft Genome Sequence for Frankia sp. Strain CeD, a Nitrogen-Fixing Actinobacterium Isolated from the Root Nodules of Casuarina equistifolia Grown in Senegal

    PubMed Central

    Ngom, Mariama; Oshone, Rediet; Hurst, Sheldon G.; Abebe-Akele, Feseha; Simpson, Stephen; Morris, Krystalynne; Sy, Mame Ourèye; Champion, Antony; Thomas, W. Kelley

    2016-01-01

    Frankia strain CeD is a member of Frankia lineage Ib that is able to reinfect plants of the Casuarina families. Here, we report a 5.0-Mbp draft genome sequence with a G+C content of 70.1% and 3,847 candidate protein-encoding genes. PMID:27056238

  4. Permanent Draft Genome Sequence of Frankia sp. Strain BR, a Nitrogen-Fixing Actinobacterium Isolated from the Root Nodules of Casuarina equisetifolia

    PubMed Central

    D’Angelo, Timothy; Oshone, Rediet; Abebe-Akele, Feseha; Simpson, Stephen; Morris, Krystalynne; Thomas, W. Kelley

    2016-01-01

    Frankia sp. strain BR is a member of Frankia lineage Ic and is able to reinfect plants of the Casuarinaceae family. Here, we report a 5.2-Mbp draft genome sequence with a G+C content of 70.0% and 4,777 candidate protein-encoding genes. PMID:27635010

  5. Draft Genome Sequence of Frankia Strain G2, a Nitrogen-Fixing Actinobacterium Isolated from Casuarina equisetifolia and Able To Nodulate Actinorhizal Plants of the Order Rhamnales

    PubMed Central

    Nouioui, Imen; Gtari, Maher; Göker, Markus; Ghodhbane-Gtari, Faten; Tisa, Louis S.; Fernandez, Maria P.; Normand, Philippe; Huntemann, Marcel; Clum, Alicia; Pillay, Manoj; Varghese, Neha; Reddy, T. B. K.; Ivanova, Natalia; Woyke, Tanja; Kyrpides, Nikos C.

    2016-01-01

    Frankia sp. strain G2 was originally isolated from Casuarina equisetifolia and is characterized by its ability to nodulate actinorhizal plants of the Rhamnales order, but not its original host. It represents one of the largest Frankia genomes so far sequenced (9.5 Mbp). PMID:27231368

  6. Draft Genome Sequence of Frankia Strain G2, a Nitrogen-Fixing Actinobacterium Isolated from Casuarina equisetifolia and Able To Nodulate Actinorhizal Plants of the Order Rhamnales.

    PubMed

    Nouioui, Imen; Gtari, Maher; Göker, Markus; Ghodhbane-Gtari, Faten; Tisa, Louis S; Fernandez, Maria P; Normand, Philippe; Huntemann, Marcel; Clum, Alicia; Pillay, Manoj; Varghese, Neha; Reddy, T B K; Ivanova, Natalia; Woyke, Tanja; Kyrpides, Nikos C; Klenk, Hans-Peter

    2016-05-26

    Frankia sp. strain G2 was originally isolated from Casuarina equisetifolia and is characterized by its ability to nodulate actinorhizal plants of the Rhamnales order, but not its original host. It represents one of the largest Frankia genomes so far sequenced (9.5 Mbp).

  7. Genome Features of the Endophytic Actinobacterium Micromonospora lupini Strain Lupac 08: On the Process of Adaptation to an Endophytic Life Style?

    PubMed Central

    Trujillo, Martha E.; Bacigalupe, Rodrigo; Pujic, Petar; Igarashi, Yasuhiro; Benito, Patricia; Riesco, Raúl; Médigue, Claudine; Normand, Philippe

    2014-01-01

    Endophytic microorganisms live inside plants for at least part of their life cycle. According to their life strategies, bacterial endophytes can be classified as “obligate” or “facultative”. Reports that members of the genus Micromonospora, Gram-positive Actinobacteria, are normal occupants of nitrogen-fixing nodules has opened up a question as to what is the ecological role of these bacteria in interactions with nitrogen-fixing plants and whether it is in a process of adaptation from a terrestrial to a facultative endophytic life. The aim of this work was to analyse the genome sequence of Micromonospora lupini Lupac 08 isolated from a nitrogen fixing nodule of the legume Lupinus angustifolius and to identify genomic traits that provide information on this new plant-microbe interaction. The genome of M. lupini contains a diverse array of genes that may help its survival in soil or in plant tissues, while the high number of putative plant degrading enzyme genes identified is quite surprising since this bacterium is not considered a plant-pathogen. Functionality of several of these genes was demonstrated in vitro, showing that Lupac 08 degraded carboxymethylcellulose, starch and xylan. In addition, the production of chitinases detected in vitro, indicates that strain Lupac 08 may also confer protection to the plant. Micromonospora species appears as new candidates in plant-microbe interactions with an important potential in agriculture and biotechnology. The current data strongly suggests that a beneficial effect is produced on the host-plant. PMID:25268993

  8. Rhodococcus cercidiphylli sp. nov., a new endophytic actinobacterium isolated from a Cercidiphyllum japonicum leaf.

    PubMed

    Li, Jie; Zhao, Guo-Zhen; Chen, Hua-Hong; Qin, Sheng; Xu, Li-Hua; Jiang, Cheng-Lin; Li, Wen-Jun

    2008-06-01

    An endophytic actinobacterium, designated YIM 65003(T), was isolated from a surface sterilized leaf sample of Cercidiphyllum japonicum collected from Yunnan province, south-west China. The morphological and chemotaxonomic properties of the isolate were typical of members of the genus Rhodococcus. Analysis of the 16S rRNA gene sequence revealed that the isolate was most closely related to Rhodococcus fascians DSM 20669(T) (99.6%) and Rhodococcus yunnanensis YIM 70056(T) (99.0%). DNA-DNA hybridization with the above microorganisms (46.3% and 48.8%, respectively), in combination with differences in the biochemical and physiological properties, suggested that strain YIM 65003(T) should be classified within a novel species of the genus Rhodococcus, for which the name Rhodococcus cercidiphylli sp. nov. is proposed, with YIM 65003(T) (=CCTCC AB 207160(T)=DSM 45141(T)) as the type strain. The 16S rRNA gene sequence of strain YIM 65003(T) has been deposited in GenBank under the accession number EU325542.

  9. Planomonospora algeriensis sp. nov., an actinobacterium isolated from a Saharan soil of Algeria.

    PubMed

    Chaabane Chaouch, Fawzia; Bouras, Noureddine; Mokrane, Salim; Bouznada, Khaoula; Zitouni, Abdelghani; Pötter, Gabriele; Spröer, Cathrin; Klenk, Hans-Peter; Sabaou, Nasserdine

    2017-02-01

    A filamentous actinobacterium, designated strain PM3(T), was isolated from a Saharan soil sample collected from Béni-Abbès, Béchar (South-West Algeria). A polyphasic taxonomic study was carried out to establish the status of strain PM3(T). The isolate was found to have morphological and chemotaxonomical properties associated with members of the genus Planomonospora. The new isolated microorganism developed cylindrical sporangia arranged in double parallel rows on aerial mycelium, each one containing a motile single sporangiospore. The cell wall of the strain was found to contain meso-diaminopimelic acid. Whole-cell hydrolysates were found to contain madurose, glucose, mannose and ribose. The predominant menaquinone was identified as MK-9(H2) (69.6%). The polar lipids detected were identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylethanolamine, phosphatidylhydroxyethanolamine and glucosamine-containing lipids. The major fatty acids were found to be C17:1ω9c (38.6%) and C17:0 (24.2%). Results of 16S rRNA gene sequence comparison revealed that strain PM3(T) shared a high degree of 16S rRNA gene sequence similarity with Planomonospora sphaerica DSM 44632(T) (99.3%), Planomonospora parontospora subsp. parontospora DSM 43177(T) (99.2%) and P. parontospora subsp. antibiotica DSM 43869(T) (99.0%). DNA-DNA hybridization values between strain PM3(T) and the type strains of the closely related species were between 58.4 and 70.1%. The combination of phylogenetic analysis, DNA-DNA relatedness data, phenotypic characteristics and chemotaxonomic data support the conclusion that strain PM3(T) represents a novel species of the genus Planomonospora, for which the name Planomonospora algeriensis sp. nov. is proposed. The type strain is PM3(T) (=DSM 46752(T) = CECT 9047(T)).

  10. Draft genome of amylolytic actinobacterium, Sinomonas humi MUSC 117(T) isolated from intertidal soil.

    PubMed

    Ser, Hooi-Leng; Tan, Wen-Si; Cheng, Huey-Jia; Yin, Wai-Fong; Chan, Kok-Gan; Lee, Learn-Han

    2015-12-01

    The amylolytic actinobacterium, Sinomonas humi MUSC 117(T) was isolated from intertidal soil from Kuantan, Malaysia. MUSC 117(T) exhibited significant starch hydrolysis activity and was chosen for further analysis. Here we report approximately 4.4 Mbp high quality genome sequence of MUSC 117(T). Availability of the genome sequence will contribute to better understanding for the strain and allow further exploitation of its biotechnological potential.

  11. Lapillicoccus jejuensis gen. nov., sp. nov., a novel actinobacterium of the family Intrasporangiaceae, isolated from stone.

    PubMed

    Lee, Soon Dong; Lee, Dong Wan

    2007-12-01

    A novel, yellow-pigmented actinobacterium was isolated from a small stone collected in Jeju, Republic of Korea. The cells of the organism, designated strain R-Ac013(T), were Gram-positive, aerobic, non-motile cocci that occurred singly or in pairs. The strain showed growth at 10-37 degrees C and pH 4.1-11.1, and tolerated 2 % NaCl. On the basis of the 16S rRNA gene sequence, the organism was phylogenetically related to members of the genera Tetrasphaera (94.6-97.1 % sequence similarity), Terrabacter (96.5 %), Knoellia (96.4 %), Terracoccus (96.4 %), Oryzihumus (96.4 %), Janibacter (96.1-96.4 %) and Intrasporangium (96.2 %). The chemotaxonomic results for the organism were as follows: ll-diaminopimelic acid as the diagnostic diamino acid in the peptidoglycan, acetyl-type murein, MK-8(H(4)) as the major menaquinone, a DNA G+C content of 74.1 mol%, and a polar lipid profile that comprised diphosphatidylglycerol and phosphatidylinositol. The fatty acid profile consisted of iso- and anteiso-methyl-branched, straight-chain saturated and monounsaturated types, the major components being iso-C(16 : 0), C(17 : 1)omega8c and iso-C(15 : 0). The combination of the phenotypic and phylogenetic data revealed that this strain represents a novel genus and species of the family Intrasporangiaceae, for which the name Lapillicoccus jejuensis gen. nov., sp. nov. is proposed. The type strain is strain R-Ac013(T) (=KCTC 19200(T)=DSM 18607(T)).

  12. Streptosporangium algeriense sp. nov., an actinobacterium isolated from desert soil.

    PubMed

    Boubetra, Dalila; Bouras, Noureddine; Zitouni, Abdelghani; Schumann, Peter; Spröer, Cathrin; Sabaou, Nasserdine; Klenk, Hans-Peter

    2015-12-08

    The taxonomic position of a novel actinobacterium, strain 169T, isolated from a sample of Algerian Saharan soil, was determined using a polyphasic taxonomic approach. The aerial mycelium produces non-motile, round to oval shaped spores, with a smooth surface, sessile or carried by short sporophores. Chemotaxonomically, the isolate 169T showed the same results as members of the genus Streptosporangium, but madurose, the so far diagnostic sugar of the genus, was not detected in the whole-cell hydrolysate. Despite the absence of sporangia, the 16S rRNA gene sequence analysis confirmed that strain 169T was a member of the genus Streptosporangium. Strain 169T was most closely related to Streptosporangium jomthongense DSM 46822T (99.3 %), which is the only non-sporangia-forming species reported among the genus. However, DNA-DNA hybridization studies with this species showed 60 % similarity. Based upon genotypic and phenotypic data, a novel species, Streptosporangium algeriense sp. nov., is proposed, with 169T (=DSM 45455T =MTCC 11561T =CCUG 62974T) as the type strain.

  13. Bounagaea algeriensis gen. nov., sp. nov., an extremely halophilic actinobacterium isolated from a Saharan soil of Algeria.

    PubMed

    Meklat, Atika; Bouras, Noureddine; Mokrane, Salim; Zitouni, Abdelghani; Schumann, Peter; Spröer, Cathrin; Klenk, Hans-Peter; Sabaou, Nasserdine

    2015-08-01

    A novel halophilic actinobacterium strain, designated H8(T), was isolated from a Saharan soil sample collected in El-Goléa, South Algeria. Strain H8(T) was identified as representing a new genus using a polyphasic taxonomic approach. Phylogenetic analysis revealed that strain H8(T) shared the highest degree of 16S rRNA gene sequence similarity with 'Mzabimyces algeriensis' DSM 46680(T) (93.0 %), Saccharopolyspora ghardaiensis DSM 45606(T) (91.2 %), Halopolyspora alba DSM 45976(T) (90.8 %) and Actinopolyspora mortivallis DSM 44261(T) (90.0 %). The strain was found to grow optimally at 28-35 °C, at pH 6.0-7.0, and in the presence of 15-25 % (w/v) NaCl. The substrate mycelium was observed to be well developed and fragmented in liquid medium and on solid medium. The aerial mycelium was observed to be moderately abundant and to form long chains with non-motile, smooth-surfaced and ovoid or spherical spores at maturity. The cell wall of strain H8(T) was found to contain meso-diaminopimelic acid. The whole-cell hydrolysates were found to mainly contain arabinose and galactose. The diagnostic phospholipid detected was phosphatidylcholine, and MK-9(H4), MK-9(H2) and MK-10(H2) were found to be the predominant menaquinones. The major cellular fatty acids were determined to be anteiso-C17:0 and iso-C15:0. The genomic DNA G+C content of strain H8(T) was determined to be 71.3 mol%. The genotypic and phenotypic data showed that the strain represents a novel genus and species, for which the name Bounagaea algeriensis gen. nov., sp. nov. is proposed, with the type strain H8(T) (=DSM 45966(T) = CECT 8470(T)).

  14. Verrucosispora sonchi sp. nov., a novel endophytic actinobacterium isolated from the leaves of common sowthistle (Sonchus oleraceus L.).

    PubMed

    Ma, Zhaoxu; Zhao, Shanshan; Cao, Tingting; Liu, Chongxi; Huang, Ying; Gao, Yuhang; Yan, Kai; Xiang, Wensheng; Wang, Xiangjing

    2016-12-01

    A novel actinobacterium, designated strain NEAU-QY3T, was isolated from the leaves of Sonchus oleraceus L. and examined using a polyphasic taxonomic approach. The organism formed single spores with smooth surface on substrate mycelia. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that the strain had a close association with the genus Verrucosispora and shared the highest sequence similarity with Verrucosispora qiuiae RtIII47T (99.17 %), an association that was supported by a bootstrap value of 94 % in the neighbour-joining tree and also recovered with the maximum-likelihood algorithm. The strain also showed high 16S rRNA gene sequence similarities to Xiangella phaseoli NEAU-J5T (98.78 %), Jishengella endophytica 202201T (98.51 %), Micromonospora eburnea LK2-10T (98.28 %), Verrucosispora lutea YIM 013T (98.23 %) and Salinispora pacifica CNR-114T (98.23 %). Furthermore, phylogenetic analysis based on the gyrB gene sequences supported the conclusion that strain NEAU-QY3T should be assigned to the genus Verrucosispora. However, the DNA-DNA hybridization relatedness values between strain NEAU-QY3T and V. qiuiae RtIII47T and V. lutea YIM 013T were below 70 %. With reference to phenotypic characteristics, phylogenetic data and DNA-DNA hybridization results, strain NEAU-QY3T was readily distinguished from its most closely related strains and classified as a new species, for which the name Verrucosispora sonchi sp. nov. is proposed. The type strain is NEAU-QY3T (=CGMCC 4.7312T=DSM 101530T).

  15. Streptosporangium becharense sp. nov., an actinobacterium isolated from Saharan soil.

    PubMed

    Chaabane Chaouch, Fawzia; Bouras, Noureddine; Mokrane, Salim; Zitouni, Abdelghani; Schumann, Peter; Spröer, Cathrin; Sabaou, Nasserdine; Klenk, Hans-Peter

    2016-04-13

    The taxonomic position of a novel actinobacterium, strain SG1T, isolated from a Saharan soil sample collected from Béni-Abbès, Béchar (South-West Algeria) was established by using a polyphasic approach. The microorganism had morphological and chemical features that were consistent with its classification in the genus Streptosporangium. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The whole-cell sugars contained ribose and glucose, but not madurose. The predominant menaquinones was MK-9(H2) and MK-9(H4). The polar lipid profile contained diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, phosphatidylhydroxymethylethanolamine, phosphatidylhydroxyethanolamine, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannosides. The predominant cellular fatty acids were C17 : 1 ω8c, iso-C16 : 0, 10-methyl C17 : 0, C18 : 1 ω9c and C17 : 0. 16S rRNA gene sequence similarity analysis supported the classification of the isolate in the genus Streptosporangium and indicated that it was most closely related to 'Streptosporangium subfuscum' DSM 46724T (99.7 % similarity), Streptosporangium pseudovulgare DSM 43181T (98.7 %), Streptosporangium fragile DSM 43847T (98.6 %) and Streptosporangium sandarakinum DSM 45763T (98.5 %). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain SG1T formed a cluster with its closest relative 'S. subfuscum' DSM 46724T. However, DNA-DNA relatedness as well as physiological and chemotaxonomical analyses showed that strain SG1T could be differentiated from its closest phylogenetic relatives. Therefore, it is proposed that strain SG1T should be classified as the type strain of a novel species in the genus Streptosporangium, for which the name Streptosporangium becharense sp. nov., is proposed. The type strain is SG1T (=DSM 46887T =CECT 8961T).

  16. Copper bioaccumulation by the actinobacterium Amycolatopsis sp. AB0.

    PubMed

    Albarracín, Virginia Helena; Winik, Beatriz; Kothe, Erika; Amoroso, María Julia; Abate, Carlos Mauricio

    2008-10-01

    Amycolatopsis sp. AB0, a copper resistant actinobacterium isolated from polluted sediments, has shown high copper specific biopsortion ability (25 mg g(-1)). Two approaches were used to confirm metal accumulation in growing cells of Amycolatopsis sp. AB0; we performed subcellular fractioning assays which showed that the retained copper was associated with the extra-cellular fraction (exopolymer, 40%), but mainly within the cells. Intracellular distribution of copper was: 86% in the cytosolic fraction, 11% at the cell wall and 3% associated with the ribosome/membrane fraction. Its copper bioaccumulation ability was corroborated by using silver enhanced staining of copper with the Timm's reagent technique, which has not been used to detect metal deposits in bacteria before. In addition, we constructed specific oligonucleotides for targeting genes coding for copper P-Type ATPases that could be involved in the copper uptake ability of this strain. A 607 bp DNA fragment was amplified and sequenced from Amycolatopsis sp AB0. BLAST search analysis showed 71% protein homology of the deduced sequence with a putative cation-transporting ATPase of Nocardia farcinica and 65% with a copper translocating ATPase of Mycobacterium flavescens. To our knowledge this is the first report of the presence of copper P-type ATPase genes in the Amycolotopsis genus.

  17. Potential application of a bioemulsifier-producing actinobacterium for treatment of vinasse.

    PubMed

    Colin, Verónica L; Cortes, Álvaro A Juárez; Aparicio, Juan D; Amoroso, María J

    2016-02-01

    Vinasse is a complex effluent created during production of ethyl alcohol, which can present serious pollution hazard in areas where it is discharged. A variety of technologies, many based upon recovery of the effluent via microbial pathways, are continually being evaluated in order to mitigate the pollution potential of vinasse. The present work reports on initial advances related to the effectiveness of the actinobacterium Streptomyces sp. MC1 for vinasse treatment. Alternative use of raw vinasse as a substrate for producing metabolites of biotechnological interest such as bioemulsifiers, was also evaluated. The strain was able to grow at very high vinasse concentrations (until 50% v/v) and remove over 50% of the biodegradable organic matter in a time period as short as 4 d. Potentially toxic metals such as Mn, Fe, Zn, As, and Pb were also effectively removed during bacterial growth. Decrease in the pollution potential of treated vinasse compared to raw effluent, was reflected in a significant increase in the vigour index of Lactuca sativa (letucce) used as bioremediation indicator. Finally, significant bioemulsifier production was detected when this strain was incubated in a vinasse-based culture medium. These results represent the first advances on the recovery and re-valuation of an actual effluent, by using an actinobacterium from our collection of cultures.

  18. Studies on bioflocculant production by a mixed culture of Methylobacterium sp. Obi and Actinobacterium sp. Mayor

    PubMed Central

    2013-01-01

    Background Bioflocculants effect the aggregation of suspended solutes in solutions thus, a viable alternative to inorganic poly-ionic and synthetic organic flocculants which are associated with deleterious health problems. Consequently, a consortium of two bacteria species were evaluated for optimized bioflocculant yield following the inadequacies of axenic cultures. Results 16S rDNA nucleotide sequencing and BLAST analysis of nucleotide sequences were used to identify the bacterial species, carbon and nitrogen sources optimally supporting bioflocculant production were assessed and the purified bioflocculant characterized. Nucleotide sequences showed 97% and 96% similarity to Methylobacterium sp. AKB-2008-KU9 and Methylobacterium sp. strain 440. The second isolate, likewise, showed 98% similarity to Actinobacterium OR-221. The sequences were deposited in GenBank as Methylobacterium sp. Obi [accession number HQ537130] and Actinobacterium sp. Mayor [accession number JF799090]. Flocculating activity of 95% was obtained in the presence of Ca2+ and heat-stability was exhibited with retention of above 70% activity at 100°C in 30 min. In addition, bioflocculant yield was about 8.203 g/l. A dose of 1 mg/ml of purified bioflocculant was optimal for the clarification of Kaolin suspension (100 ml) following Jar test. FTIR spectrum revealed the presence of carboxyl and hydroxyl functional groups amongst others. Conclusions The mixed culture produced bioflocculant with high flocculating activity and an improved yield. The efficiency observed with jar test may imply industrial applicability. PMID:23915393

  19. Permanent Draft Genome Sequence for Frankia sp. Strain EI5c, a Single-Spore Isolate of a Nitrogen-Fixing Actinobacterium, Isolated from the Root Nodules of Elaeagnus angustifolia

    PubMed Central

    D’Angelo, Timothy; Oshone, Rediet; Abebe-Akele, Feseha; Simpson, Stephen; Morris, Krystalynne; Thomas, W. Kelley

    2016-01-01

    Frankia sp. strain EI5c is a member of Frankia lineage III, which is able to reinfect plants of the Eleagnaceae, Rhamnaceae, Myricaceae, and Gymnostoma, as well as the genus Alnus. Here, we report the 6.6-Mbp draft genome sequence of Frankia sp. strain EI5c with a G+C content of 72.14 % and 5,458 candidate protein-encoding genes. PMID:27389275

  20. Permanent Draft Genome Sequence for Frankia sp. Strain EI5c, a Single-Spore Isolate of a Nitrogen-Fixing Actinobacterium, Isolated from the Root Nodules of Elaeagnus angustifolia.

    PubMed

    D'Angelo, Timothy; Oshone, Rediet; Abebe-Akele, Feseha; Simpson, Stephen; Morris, Krystalynne; Thomas, W Kelley; Tisa, Louis S

    2016-07-07

    Frankia sp. strain EI5c is a member of Frankia lineage III, which is able to reinfect plants of the Eleagnaceae, Rhamnaceae, Myricaceae, and Gymnostoma, as well as the genus Alnus Here, we report the 6.6-Mbp draft genome sequence of Frankia sp. strain EI5c with a G+C content of 72.14 % and 5,458 candidate protein-encoding genes.

  1. Description of Tessaracoccus profundi sp.nov., a deep-subsurface actinobacterium isolated from a Chesapeake impact crater drill core (940 m depth)

    USGS Publications Warehouse

    Finster, K.W.; Cockell, C.S.; Voytek, M.A.; Gronstal, A.L.; Kjeldsen, K.U.

    2009-01-01

    A novel actinobacterium, designated CB31T, was isolated from a 940 m depth sample of a drilling core obtained from the Chesapeake meteor impact crater. The strain was isolated aerobically on R2A medium agar plates supplemented with NaCl (20 g l-1) and MgCl2???6H 2O (3 g l-1). The colonies were circular, convex, smooth and orange. Cells were slightly curved, rod-shaped in young cultures and often appeared in pairs. In older cultures cells were coccoid. Cells stained Gram-positive, were non-motile and did not form endospores. The diagnostic diamino acid of the peptidoglycan was ll-diaminopimelic acid. The polar lipids included phosphatidylglycerol, diphosphatidglycerol, four different glycolipids, two further phospholipids and one unidentified lipid. The dominant menaquinone was MK-9(H4) (70%). The major cellular fatty acid was anteiso C15:0 (83%). The DNA G + C content was 68 mol%. The strain grew anaerobically by reducing nitrate to nitrite or by fermenting glucose. It was catalase positive and oxidase negative. It grew between 10 and 45??C, with an optimum between 35 and 40??C. The pH range for growth was 5.7-9.3, with an optimum at pH 7.5. The closest phylogenetic neighbors based on 16S rRNA gene sequence identity were members of the genus Tessaracoccus (95-96% identity). On the basis of phenotypic and phylogenetic distinctiveness, strain CB31T is considered to represent a novel species of the genus Tessaracoccus, for which we propose the name Tessaracoccus profundi sp. nov.. It is the first member of this genus that has been isolated from a deep subsurface environment. The type strain is CB31T (=NCIMB 14440T = DSM 21240T). ?? 2009 Springer Science+Business Media B.V.

  2. Genome Sequence of Streptomyces sp. H-KF8, a Marine Actinobacterium Isolated from a Northern Chilean Patagonian Fjord.

    PubMed

    Undabarrena, Agustina; Ugalde, Juan Antonio; Castro-Nallar, Eduardo; Seeger, Michael; Cámara, Beatriz

    2017-02-09

    Streptomyces sp. H-KF8 is a fjord-derived marine actinobacterium capable of producing antimicrobial activity. Streptomyces sp. H-KF8 was isolated from sediments of the Comau fjord, located in the northern Chilean Patagonia. Here, we report the 7.7-Mb genome assembly, which represents the first genome of a Chilean marine actinobacterium.

  3. Genome Sequence of Streptomyces sp. H-KF8, a Marine Actinobacterium Isolated from a Northern Chilean Patagonian Fjord

    PubMed Central

    Undabarrena, Agustina; Ugalde, Juan Antonio; Castro-Nallar, Eduardo; Seeger, Michael

    2017-01-01

    ABSTRACT Streptomyces sp. H-KF8 is a fjord-derived marine actinobacterium capable of producing antimicrobial activity. Streptomyces sp. H-KF8 was isolated from sediments of the Comau fjord, located in the northern Chilean Patagonia. Here, we report the 7.7-Mb genome assembly, which represents the first genome of a Chilean marine actinobacterium. PMID:28183776

  4. Description of Citricoccus nitrophenolicus sp. nov., a para-nitrophenol degrading actinobacterium isolated from a wastewater treatment plant and emended description of the genus Citricoccus Altenburger et al. 2002.

    PubMed

    Nielsen, Marie Bank; Kjeldsen, Kasper Urup; Ingvorsen, Kjeld

    2011-03-01

    A novel actinobacterium, designated PNP1(T), was isolated from a wastewater treatment plant at a pesticide factory by selective enrichment with para-nitrophenol. The strictly aerobic strain PNP1(T) grew with para-nitrophenol as the sole carbon and energy source. Metabolism of para-nitrophenol resulted in the stoichiometric release of nitrite. When incubated with both para-nitrophenol and acetate, para-nitrophenol was degraded and utilized as growth substrate prior to acetate. When grown on acetate (in the absence of ammonium) both nitrite and nitrate served as nitrogen sources, nitrate being quantitatively reduced to nitrite which accumulated in cultures during aerobic growth. Cells were coccoid and stained Gram-positive, were non-motile and did not form endospores. Colonies of strain PNP1(T) on agar medium were bright yellow, circular and smooth. The dominant menaquinone was MK-8(H(2)) (54%) and the major cellular fatty acid was anteiso C15:0 (75%). Strain PNP1(T) grew optimally at 27°C, at pH 8-8.5, at salinities 3% (w/v) NaCl, yet exhibited a substantial halotolerance with growth occurring at salinities up to 17% (w/v) NaCl. In addition to para-nitrophenol, a range of sugars, short chain fatty acids and alcohols served as electron donors for growth. The DNA G + C mol% was 68%. The genotypic and phenotypic properties suggest that strain PNP1(T) represents a novel species of the actinobacterial genus Citricoccus for which the name Citricoccus nitrophenolicus is proposed. It is the first member of this genus that has been reported to hydrolyze and grow on para-nitrophenol. The type strain is PNP1(T) (=DSM 23311(T) = CCUG 59571(T)).

  5. Actinocrinis puniceicyclus gen. nov., sp. nov., an actinobacterium isolated from an acidic spring.

    PubMed

    Kim, Joong-Jae; Marjerrison, Colbran E; Cornish Shartau, Sabrina L; Brady, Allyson L; Sharp, Christine E; Rijpstra, W Irene C; Sinninghe Damsté, Jaap S; Schumann, Peter; Grasby, Stephen E; Dunfield, Peter F

    2017-03-01

    An aerobic, mildly acidophilic actinobacterium was isolated from the Ochre Beds bog in Kootenay National Park, Canada. Cells of isolate OB1T were Gram-stain-positive, non-motile, pink- to purple-pigmented filaments. The pH range for growth was pH 3.5-6.5 (optimum pH 5.5), and the temperature range was 13-30°C. The major cellular fatty acids were i-C16 : 0 (28.5 %), i-C15 : 0 (14.6 %) and ai-C15 : 0 (14.3 %), and the major polar lipid was phosphohexose. The major quinone was menaquinone-11 (MK-11), and the peptidoglycan type was A1γ. The DNA G+C content was 70.2 %. Along with growth on complex media including yeast extract, proteose peptone, casamino acids and tryptic soy broth, growth occured on mono- and disaccharides (glucose, sucrose, galactose and xylose) and polysaccharides (starch, gellan, pectin, xylan and alginate). Anaerobic growth was not observed. The cells did not fix atmospheric nitrogen. On the basis of comparative 16S rRNA gene sequence analysis, this isolate belonged to the family Actinospicaceae, in the suborder Catenulisporineae of the order Actinomycetales. The most closely related species was Actinospica robiniae. However, the 16S rRNA gene sequence identity to this bacterium was low (92.8 %) and there were several chemotaxonomic differences from this species. We therefore propose a novel genus and species, Actinocrinis puniceicyclus gen. nov., sp. nov., with strain OB1T (=DSM 45618T=ATCC BAA-2771T) as the type strain.

  6. Antibacterial and brine shrimp lethality effect of marine actinobacterium Streptomyces sp. CAS72 against human pathogenic bacteria

    PubMed Central

    Sivasankar, Palaniappan; Manivasagan, Panchanathan; Vijayanand, Packiyaraj; Sivakumar, Kannan; Sugesh, Shanmugam; Poongodi, Subramaniam; Maharani, Viswanathan; Vijayalakshmi, Shanmugam; Balasubramanian, Thangavel

    2013-01-01

    Objective To investigate the in vitro antibacterial activity against human pathogenic bacteria and brine shrimp lethality bioassay of the marine actinobacterium. Methods Forty six marine actinobacterial strains were isolated from sediment samples of Uppanar estuary, Cuddalore, India. Preliminary screening was done by cross-streak method and the potential strain was identified by morphological, chemotaxonomical and molecular methods. Fermentation was done and the metabolite was obtained by liquid-liquid extraction using ethyl acetate and purified by silica gel (100-200 mesh) column chromatography. The purified metabolite was tested for antibacterial activity, minimal inhibitory concentration and brine shrimp lethality bioassay. Results Among the forty six strains, CAS72 was found effective against human pathogenic bacteria. The strain CAS72 was identified as Streptomyces sp. The purified metabolite exhibited a significant in vitro antibacterial activity. The MIC value was also determined against human pathogenic bacteria and a strong cytotoxic activity in brine shrimp lethality assay was observed and the LC50 value was 23.5 µg/mL. Conclusions The present investigation reveals that the marine actinobacteria are well obtainable in Uppanar estuary environment and it can provide a definite source for novel bioactive metabolites.

  7. Promicromonospora endophytica sp. nov., an endophytic actinobacterium isolated from the root of an Australian native Grey Box tree.

    PubMed

    Kaewkla, Onuma; Franco, Christopher M M

    2012-07-01

    A novel aerobic actinobacterium, strain EUM 273(T), was isolated from the root of a Grey Box tree (Eucalyptus microcarpa Maiden). Cells were Gram-staining-positive with well-developed substrate mycelia which were non-motile and rod-like, with coccoid elements. Phylogenetic evaluation based on 16S rRNA gene sequence analysis placed the isolate as a member of the family Promicromonosporaceae that was most closely related to Promicromonospora xylanilytica YIM 61515(T) (98.2%) and Promicromonospora vindobonensis V45(T) (98%). Chemotaxonomic data including cell wall components, major menaquinone and major fatty acids confirmed the affiliation of strain EUM 273(T) to the genus Promicromonospora. The results of the phylogenetic analysis, including physiological and biochemical studies in combination with DNA-DNA hybridization, allowed the genotypic and phenotypic differentiation of strain EUM 273(T) from the closest related species with validly published names. The name proposed for the novel species is Promicromonospora endophytica sp. nov. The type strain is EUM 273(T) (=DSM 23716(T)=NRRL B-24816(T)).

  8. Hoyosella rhizosphaerae sp. nov., a halotolerant actinobacterium isolated from rhizosphere soil of Suaeda salsa, and emended description of the genus Hoyosella.

    PubMed

    Li, Xiao-Jun; Liu, Shao-Wei; Jiang, Zhong-Ke; Wu, Gang; Sun, Cheng-Hang

    2016-11-01

    A halotolerant actinobacterium, designated J12GA03T, was isolated from a rhizosphere soil sample of Suaeda salsa collected from a dried saline lake in Hebei Province, China. Cells were Gram-staining-positive, non-motile and non-spore-forming cocci. Strain J12GA03T grew optimally at 28‒37 °C, 0‒3 % NaCl (w/v) and pH 6.5‒7.5. It contained meso-diaminopimelic acid as the diagnostic diamino acid and arabinose, galactose and ribose as the diagnostic whole-cell sugars. MK-8 and MK-7 were detected as predominant menaquinones. Major fatty acids were C17 : 1ω8c, C16 : 0 and C17 : 0. Polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylinositol, phosphatidylglycerol, phosphoglycolipids, glycolipids, unidentified phospholipids and additional lipids. The muramyl residue was acetyl. Mycolic acids (34-38 carbon atoms) were present. The G+C content of the genomic DNA was 55.8 mol%. It shared the highest 16S rRNA gene sequence similarities with Amycolicicoccus subflavus DQS3-9A1T (98.18 %) and Hoyosella altamirensis OFN S31T (97.75 %). Phylogenetic trees showed that strain J12GA03T firmly formed a distinct monophyletic branch in the clade with A.subflavus DQS3-9A1T and H.altamirensis DSM 45258T. The levels of DNA-DNA relatedness with A.subflavus DSM 45089T and H.altamirensis DSM 45258T were 39.7±3.9 % and 35.7±3.0 %, respectively. Combining the evidence from the polyphasic taxonomic study, strain J12GA03T represents a novel species of the genus Hoyosella, for which the name Hoyosella rhizosphaerae sp. nov. is proposed. The type strain is J12GA03T (=DSM 101985T=CGMCC 1.15478T).

  9. NASA LaRC Strain Gage Balance Design Concepts

    NASA Technical Reports Server (NTRS)

    Rhew, Ray D.

    1999-01-01

    The NASA Langley Research Center (LaRC) has been designing strain-gage balances for more than fifty years. These balances have been utilized in Langley's wind tunnels, which span over a wide variety of aerodynamic test regimes, as well as other ground based test facilities and in space flight applications. As a result, the designs encompass a large array of sizes, loads, and environmental effects. Currently Langley has more than 300 balances available for its researchers. This paper will focus on the design concepts for internal sting mounted strain-gage balances. However, these techniques can be applied to all force measurement design applications. Strain-gage balance concepts that have been developed over the years including material selection, sting, model interfaces, measuring, sections, fabrication, strain-gaging and calibration will be discussed.

  10. Myceligenerans cantabricum sp. nov., a barotolerant actinobacterium isolated from a deep cold-water coral.

    PubMed

    Sarmiento-Vizcaíno, Aida; González, Verónica; Braña, Alfredo F; Molina, Axayacatl; Acuña, José L; García, Luis A; Blanco, Gloria

    2015-04-01

    An actinobacterium strain (M-201(T)) was isolated from a deep-sea scleractinian coral (Fam. Caryophillidae) collected at 1500 m depth in the Avilés Canyon in the Cantabrian Sea, Asturias, Spain. Strain M-201(T) grew at pH 6.0-9.0 (optimum pH 7.0), between 4 and 37 °C (optimum 28 °C) and at salinities of 0.5-10.5% (w/v) NaCl (optimum 0.5-3.0%). The peptidoglycan contained the amino acids Lys, Ala, Thr, Glu and one unknown amino acid component, and belonged to type A4α, and the cell-wall sugars are glucose, mannose and galactose. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, an unknown phosphoglycolipid and seven unknown glycolipids. The predominant menaquinones were MK-9(H4) and MK-9(H6). Major cellular fatty acids were anteiso-C(15 : 0), iso-C(15 : 0) and anteiso-C(17 : 0). The genomic DNA G+C content was 72.4 mol%. The chemotaxonomic properties supported the affiliation of strain M-201(T) to the genus Myceligenerans . Phylogenetic analysis based on 16S rRNA gene sequences revealed that the organism was most closely related to Myceligenerans crystallogenes CD12E2-27(T) (98.2% 16S rRNA gene sequence similarity). However, it had a relatively low DNA-DNA relatedness value with the above strain (48%). The isolate showed antibiotic activity against Escherichia coli , Micrococcus luteus ATCC 14452 and Saccharomyces cerevisiae var. carlsbergensis. To the best of our knowledge, this is the first report of antibiotic production in the genus Myceligenerans . The differences in phenotypic, metabolic, ecological and phylogenetic characteristics justify the proposal of a novel species of the genus Myceligenerans , Myceligenerans cantabricum sp. nov., with M-201(T) ( = CECT 8512(T) = DSM 28392(T)) as the type strain.

  11. Nocardioides albidus sp. nov., an actinobacterium isolated from garden soil.

    PubMed

    Singh, Hina; Du, Juan; Trinh, Huan; Won, KyungHwa; Yang, Jung-Eun; Yin, ChangShik; Kook, MooChang; Yi, Tae-Hoo

    2016-01-01

    A novel bacterial strain, designated THG-S11.7T, was isolated from garden soil in Incheon, South Korea. Cells of the strain were Gram-stain-positive, aerobic, non-motile cocci, and were catalase- and oxidase-positive. Colonies of the strain were white. Strain THG-S11.7T grew optimally at 28 °C, at pH 7.0 and in the presence of 2.0 % NaCl. 16S rRNA gene sequence analysis indicated that the strain was a member of the genus Nocardioides. Strain THG-S11.7T showed a 16S rRNA gene sequence similarity of 98.2 % to Nocardioides kongjuensis KCTC 19054T, 98.0 % to Nocardioides caeni KCTC 19600T, 97.9 % to Nocardioides daeguensis KCTC 19799T, 97.8 % to Nocardioides nitrophenolicus KCTC 047BPT, 97.6 % to Nocardioides aromaticivorans KACC 20613T, 97.5 % to Nocardioides simplex KACC 20620T and 97.0 % to Nocardioides ginsengisoli KCTC 19135T. DNA-DNA relatedness values between strain THG-S11.7T and the closest phylogenetic neighbours were below 45.0 % and the DNA G+C content of strain THG-S11.7T was 72.2 mol%. Strain THG-S11.7T was characterized chemotaxonomically as having ll-diaminopimelic acid in the cell-wall peptidoglycan and menaquinone MK-8(H4) as the predominant isoprenoid quinone. The major phospholipid was determined to be diphosphatidylglycerol. The major cellular fatty acids of strain THG-S11.7T were iso-C15 : 0, C16 : 0 and iso-C16 : 0. Based on the phenotypic, genotypic and phylogenetic analyses, it is proposed that the isolate represents a novel species of the genus Nocardioides, for which the name Nocardioides albidus sp. nov. is proposed. The type strain is THG-S11.7T ( = KCTC 39607T = CCTCC AB 2015297T).

  12. Saccharothrix isguenensis sp. nov., an actinobacterium isolated from desert soil.

    PubMed

    Bouznada, Khaoula; Bouras, Noureddine; Mokrane, Salim; Chaabane Chaouch, Fawzia; Zitouni, Abdelghani; Pötter, Gabriele; Spröer, Cathrin; Klenk, Hans-Peter; Sabaou, Nasserdine

    2016-11-01

    A novel actinobacterial strain, designated MB27T, was isolated from a Saharan soil sample collected in Mzab region (Ghardaïa province, South Algeria). Strain MB27T was characterized following a polyphasic taxonomic approach. This strain produced a branched and fragmented substrate mycelium, which was found to have a yellowish orange colour. A white scanty aerial mycelium was produced on most media tested. Chemotaxonomic and phylogenetic studies clearly demonstrated that strain MB27T belongs to the family Pseudonocardiaceae and is closely related to the genus Saccharothrix. Cell-wall hydrolysates contained meso-diaminopimelic acid but not glycine, and whole-cell hydrolysates contained galactose, glucose, ribose and small amounts of mannose and rhamnose. The detected phospholipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannosides. Mycolic acids were not detected while the predominant fatty acid was iso-branched hexadecanoate (iso-C16 : 0). The major menaquinone was MK-9(H4). Results of 16S rRNA gene sequence comparisons revealed that strain MB27T shairs the highest degree of similarity with Saccharothrix ecbatanensis DSM 45486T (99.8%), Saccharothrix hoggarensis DSM 45457T (99.3 %), Saccharothrix longispora DSM 43749T (98.6 %) and Saccharothrix yanglingensis DSM 45665T (98.6 %). However, it exhibited only 11-42 % DNA-DNA relatedness to the neighbouring Saccharothrixspecies. On the basis of phenotypic characteristics, 16S rRNA gene sequence comparisons and DNA-DNA hybridization, strain MB27T is shown to represent a novel species of the genus Saccharothrix, for which the name Saccharothrix isguenensis sp. nov. (type strain MB27T=DSM 46885T=CECT 9045T) is proposed.

  13. Actinomadura adrarensis sp. nov., an actinobacterium isolated from Saharan soil.

    PubMed

    Lahoum, Abdelhadi; Bouras, Noureddine; Verheecke, Carol; Mathieu, Florence; Schumann, Peter; Spröer, Cathrin; Klenk, Hans-Peter; Sabaou, Nasserdine

    2016-04-26

    A novel actinobacterial strain, designated ACD12T, was isolated from a Saharan soil sample collected from Adrar province, South of Algeria. A polyphasic study was carried out to establish the taxonomic position of this strain. Strain ACD12T was observed to form extensively branched substrate mycelia. Aerial mycelium was absent or weakly produced on all tested media, while spore chains are short with hooked and irregular spirals forms (2-3 turns). The dominant diaminopimelic acid isomer in the cell wall was meso-diaminopimelic acid. Glucose, ribose, galactose, mannose and madurose occur in whole-cell hydrolysates. The major phospholipid was diphosphatidylglycerol and phosphatidylinositol. The predominant menaquinone was MK-9(H6). The fatty acid profile was characterized by the presence of C16:0, C17:0, C15:0, C18:0, C18:1 cis9 and iso-C16:0. Results of 16S rRNA gene sequence comparison revealed that strain ACD12T shared the highest degree of 16S rRNA gene sequence similarity with Actinomadura sputi DSM 45233T (98.3 %) and Actinomadura hallensis DSM 45043T (97.8 %). All tree-making algorithms used also supported the position that strain ACD12T formed a distinct clade with its most closely related species. In addition, DNA-DNA hybridization revealed only 39.8 % relatedness with A. sputi DSM 45233T and 18.7 % relatedness with A. hallensis DSM 45043T. The combined phenotypic and genotypic data showed that the isolated strain represents a novel species of the genus Actinomadura, for which the name Actinomadura adrarensis sp. nov., is proposed, with the type strain ACD12T (=DSM 46745T = CECT 8842T).

  14. Actinophytocola algeriensis sp. nov., an actinobacterium isolated from Saharan soil.

    PubMed

    Bouznada, Khaoula; Bouras, Noureddine; Schumann, Peter; Spröer, Cathrin; Sabaou, Nasserdine; Klenk, Hans-Peter

    2016-05-04

    Throughout our investigations for new actinobacterial taxa, a new actinobacterial strain, designated MB20T, was isolated from a Saharan soil sample, collected in Mzab region (Ghardaïa province, South Algeria). In order to reveal its taxonomic position, the novel strain was characterized following a polyphasic taxonomic approach. It was noticed that strain MB20T produce white branched and fragmented substrate mycelium with no aerial mycelium on the most tested media. Chemotaxonomic and phylogenetic studies clearly demonstrated that the strain MB20T belonged to the family Pseudonocardiaceae and was closely related to the genus Actinophytocola. Cell-wall hydrolysates contained meso-diaminopimelic acid but not glycine, and whole-cell hydrolysates contained galactose, glucose and ribose. The diagnostic phospholipid was phosphatidylethanolamine. Mycolic acids were not detected while the predominant fatty acid was found to be iso-branched hexadecanoate (iso-C16 : 0). The major menaquinone was MK-9(H4). Results of the 16S rRNA gene sequence comparison revealed that strain MB20T shared the highest degree of similarity with Actinophytocola gilvus DSM 45828T (98.5 %), Actinophytocola corallina DSM 45659T (98.0 %) and Actinophytocola timorensis DSM 45660T (97.5 %). However, DNA-DNA hybridization studies showed only 32.9 % similarity with A. timorensis, 23.7 % similarity with A. gilvus and 17.9 % similarity with A. corallina. On the basis of phenotypic characteristics, 16S rRNA gene sequence comparisons and DNA-DNA hybridization, strain MB20T revealed to be a novel species of the genus Actinophytocola, for which the name Actinophytocola algeriensis sp. nov. (type strain MB20T =DSM 46746T = CECT 8960T) is proposed.

  15. Draft Genome Sequence of Arthrobacter crystallopoietes Strain BAB-32, Revealing Genes for Bioremediation

    PubMed Central

    Joshi, M. N.; Pandit, A. S.; Sharma, A.; Pandya, R. V.; Desai, S. M.; Saxena, A. K.

    2013-01-01

    Arthrobacter crystallopoietes strain BAB-32, a Gram-positive obligate aerobic actinobacterium having potential application in bioremediation and bioreduction of a few metals, was isolated from rhizosphere soil of Gandhinagar, Gujarat, India. The draft genome (4.3 Mb) of the strain revealed a few vital gene clusters involved in the metabolism of aromatic compounds, zinc, and sulfur. PMID:23833141

  16. Saccharothrix ghardaiensis sp. nov., an actinobacterium isolated from Saharan soil.

    PubMed

    Bouznada, Khaoula; Bouras, Noureddine; Mokrane, Salim; Chaabane Chaouch, Fawzia; Zitouni, Abdelghani; Pötter, Gabriele; Spröer, Cathrin; Klenk, Hans-Peter; Sabaou, Nasserdine

    2017-03-01

    The taxonomic position of a new Saccharothrix strain, designated MB46(T), isolated from a Saharan soil sample collected in Mzab region (Ghardaïa province, South Algeria) was established following a polyphasic approach. The novel microorganism has morphological and chemical characteristics typical of the members of the genus Saccharothrix and formed a phyletic line at the periphery of the Saccharothrix espanaensis subcluster in the 16S rRNA gene dendrograms. Results of the 16S rRNA gene sequence comparisons revealed that strain MB46(T) shares high degrees of similarity with S. espanaensis DSM 44229(T) (99.2%), Saccharothrix variisporea DSM 43911(T) (98.7%) and Saccharothrix texasensis NRRL B-16134(T) (98.6%). However, the new strain exhibited only 12.5-17.5% DNA relatedness to the neighbouring Saccharothrix spp. On the basis of phenotypic characteristics, 16S rRNA gene sequence comparisons and DNA-DNA hybridizations, strain MB46(T) is concluded to represent a novel species of the genus Saccharothrix, for which the name Saccharothrix ghardaiensis sp. nov. (type strain MB46(T) = DSM 46886(T) = CECT 9046(T)) is proposed.

  17. Actinomadura algeriensis sp. nov., an actinobacterium isolated from Saharan soil.

    PubMed

    Lahoum, Abdelhadi; Bouras, Noureddine; Mathieu, Florence; Schumann, Peter; Spröer, Cathrin; Klenk, Hans-Peter; Sabaou, Nasserdine

    2016-01-01

    During the course of a screening programme for new taxa of actinobacteria, a strain designated ACD1(T), was isolated from a Saharan soil in the Hoggar region (Algeria). The taxonomic position of this strain was determined using a polyphasic taxonomic approach. The strain was observed to form extensively branched, non-fragmenting substrate mycelium, and aerial mycelium with straight to flexuous, hooked and irregular spirals (1-2 turns) forming short chains of spores. The diamino acid present in the cell wall is meso-diaminopimelic acid. Galactose, glucose, madurose, mannose and ribose occur in whole-cell hydrolysates. The diagnostic phospholipids detected were diphosphatidylglycerol and phosphatidylinositol. The major menaquinones were identified as MK-9 (H4) and MK-9 (H2). The major fatty acids were found to be C16:0, C18:1 cis9, iso-C16:0 and 10-methyl C18:0. Phylogenetic analysis based on the 16S rRNA gene showed that the strain belongs to the genus Actinomadura, and is closely related to Actinomadura sediminis DSM 45500(T) (98.5 % similarity) and Actinomadura cremea subsp. cremea DSM 43676(T) (98.3 % similarity). However, DNA-DNA hybridization revealed only 48.0 % relatedness with A. sediminis DSM 45500(T) and 33.2 % relatedness with A. cremea subsp. cremea DSM 43676(T). The combined phenotypic and genotypic data showed that the strain represents a novel species of the genus Actinomadura, for which the name Actinomadura algeriensis sp. nov. is proposed, with the type strain ACD1(T) (= DSM 46744(T) = CECT 8841(T)).

  18. High Sensitivity MEMS Strain Sensor: Design and Simulation

    PubMed Central

    Mohammed, Ahmed A. S.; Moussa, Walied A.; Lou, Edmond

    2008-01-01

    In this article, we report on the new design of a miniaturized strain microsensor. The proposed sensor utilizes the piezoresistive properties of doped single crystal silicon. Employing the Micro Electro Mechanical Systems (MEMS) technology, high sensor sensitivities and resolutions have been achieved. The current sensor design employs different levels of signal amplifications. These amplifications include geometric, material and electronic levels. The sensor and the electronic circuits can be integrated on a single chip, and packaged as a small functional unit. The sensor converts input strain to resistance change, which can be transformed to bridge imbalance voltage. An analog output that demonstrates high sensitivity (0.03mV/με), high absolute resolution (1με) and low power consumption (100μA) with a maximum range of ±4000με has been reported. These performance characteristics have been achieved with high signal stability over a wide temperature range (±50°C), which introduces the proposed MEMS strain sensor as a strong candidate for wireless strain sensing applications under harsh environmental conditions. Moreover, this sensor has been designed, verified and can be easily modified to measure other values such as force, torque…etc. In this work, the sensor design is achieved using Finite Element Method (FEM) with the application of the piezoresistivity theory. This design process and the microfabrication process flow to prototype the design have been presented. PMID:27879841

  19. Protein design in systems metabolic engineering for industrial strain development.

    PubMed

    Chen, Zhen; Zeng, An-Ping

    2013-05-01

    Accelerating the process of industrial bacterial host strain development, aimed at increasing productivity, generating new bio-products or utilizing alternative feedstocks, requires the integration of complementary approaches to manipulate cellular metabolism and regulatory networks. Systems metabolic engineering extends the concept of classical metabolic engineering to the systems level by incorporating the techniques used in systems biology and synthetic biology, and offers a framework for the development of the next generation of industrial strains. As one of the most useful tools of systems metabolic engineering, protein design allows us to design and optimize cellular metabolism at a molecular level. Here, we review the current strategies of protein design for engineering cellular synthetic pathways, metabolic control systems and signaling pathways, and highlight the challenges of this subfield within the context of systems metabolic engineering.

  20. Draft Genome Sequence of Curtobacterium sp. Strain UCD-KPL2560 (Phylum Actinobacteria).

    PubMed

    Klein, Brian A; Lemon, Katherine P; Faller, Lina L; Jospin, Guillaume; Eisen, Jonathan A; Coil, David A

    2016-10-06

    Here, we present the draft genome sequence of the actinobacterium Curtobacterium sp. strain UCD-KPL2560, which was isolated from the running surface of an indoor track field house in Medford, MA, USA (42.409716°N, -71.115169°W). The genome assembly contains 3,480,487 bp in 156 contigs.

  1. Draft Genome Sequence of Dietzia sp. Strain UCD-THP (Phylum Actinobacteria)

    PubMed Central

    Diep, Amanda L.; Lang, Jenna M.; Darling, Aaron E.; Coil, David A.

    2013-01-01

    Here, we present the draft genome sequence of an actinobacterium, Dietzia sp. strain UCD-THP, isolated from a residential toilet handle. The assembly contains 3,915,613 bp. The genome sequences of only two other Dietzia species have been published, those of Dietzia alimentaria and Dietzia cinnamea. PMID:23661480

  2. Draft Genome Sequence of Curtobacterium flaccumfaciens Strain UCD-AKU (Phylum Actinobacteria)

    PubMed Central

    Flanagan, Jennifer C.; Lang, Jenna M.; Darling, Aaron E.; Coil, David A.

    2013-01-01

    Here we present the draft genome of an actinobacterium, Curtobacterium flaccumfaciens strain UCD-AKU, isolated from a residential carpet. The genome assembly contains 3,692,614 bp in 130 contigs. This is the first member of the Curtobacterium genus to be sequenced. PMID:23682147

  3. Draft Genome Sequence of Curtobacterium sp. Strain UCD-KPL2560 (Phylum Actinobacteria)

    PubMed Central

    Klein, Brian A.; Faller, Lina L.; Jospin, Guillaume; Eisen, Jonathan A.; Coil, David A.

    2016-01-01

    Here, we present the draft genome sequence of the actinobacterium Curtobacterium sp. strain UCD-KPL2560, which was isolated from the running surface of an indoor track field house in Medford, MA, USA (42.409716°N, -71.115169°W). The genome assembly contains 3,480,487 bp in 156 contigs. PMID:27795241

  4. Draft Genome Sequence of Pseudonocardia autotrophica Strain DSM 43083, an Efficient Producer of Peroxidases for Lignin Modification

    PubMed Central

    Rais, Dominik; Kirstahler, Philipp; Vainshtein, Yevhen; Rupp, Steffen; Zibek, Susanne

    2017-01-01

    ABSTRACT Pseudonocardia autotrophica strain DSM 43083 is a filamentous actinobacterium and was described to degrade or modify lignin. Here, we present its draft genome sequence, with a size of 5.8 Mb, to unravel the gene set coding for promising monooxygenases, dioxygenases, and DyP-type peroxidases associated with aromatic metabolism and lignin modification. PMID:28153904

  5. Knitted Strain Sensors: Impact of Design Parameters on Sensing Properties

    PubMed Central

    Atalay, Ozgur; Kennon, William Richard

    2014-01-01

    This paper presents a study of the sensing properties exhibited by textile-based knitted strain sensors. Knitted sensors were manufactured using flat-bed knitting technology, and electro-mechanical tests were subsequently performed on the specimens using a tensile testing machine to apply strain whilst the sensor was incorporated into a Wheatstone bridge arrangement to allow electrical monitoring. The sensing fabrics were manufactured from silver-plated nylon and elastomeric yarns. The component yarns offered similar diameters, bending characteristics and surface friction, but their production parameters differed in respect of the required yarn input tension, the number of conductive courses in the sensing structure and the elastomeric yarn extension characteristics. Experimental results showed that these manufacturing controls significantly affected the sensing properties of the knitted structures such that the gauge factor values, the working range and the linearity of the sensors varied according to the knitted structure. These results confirm that production parameters play a fundamental role in determining the physical behavior and the sensing properties of knitted sensors. It is thus possible to manipulate the sensing properties of knitted sensors and the sensor response may be engineered by varying the production parameters applied to specific designs. PMID:24608010

  6. Computational methods in metabolic engineering for strain design.

    PubMed

    Long, Matthew R; Ong, Wai Kit; Reed, Jennifer L

    2015-08-01

    Metabolic engineering uses genetic approaches to control microbial metabolism to produce desired compounds. Computational tools can identify new biological routes to chemicals and the changes needed in host metabolism to improve chemical production. Recent computational efforts have focused on exploring what compounds can be made biologically using native, heterologous, and/or enzymes with broad specificity. Additionally, computational methods have been developed to suggest different types of genetic modifications (e.g. gene deletion/addition or up/down regulation), as well as suggest strategies meeting different criteria (e.g. high yield, high productivity, or substrate co-utilization). Strategies to improve the runtime performances have also been developed, which allow for more complex metabolic engineering strategies to be identified. Future incorporation of kinetic considerations will further improve strain design algorithms.

  7. New design for temperature-strain discrimination using fiber Bragg gratings embedded in laminated composites

    NASA Astrophysics Data System (ADS)

    Rodriguez-Cobo, L.; Marques, A. T.; López-Higuera, J. M.; Santos, J. L.; Frazão, O.

    2013-10-01

    A new smart structure based on fiber Bragg gratings (FBGs) embedded into composite laminates for temperature and strain simultaneous measurement has been designed and experimentally tested. Two holes have been drilled at preset locations in the composite plate to create different strain sensitivities at different locations. The proposed design has been compared to three reference sensing heads also based on embedding FBGs into composite materials. Experimental results agree remarkably well with mechanical simulations and validate all the tested designs for the temperature-strain discrimination. Based on the same principle, another sensing head with a long single FBG embedded has also been designed and experimentally tested, obtaining temperature independent strain measurement.

  8. Branimycins B and C, Antibiotics Produced by the Abyssal Actinobacterium Pseudonocardia carboxydivorans M-227.

    PubMed

    Braña, Alfredo F; Sarmiento-Vizcaíno, Aida; Pérez-Victoria, Ignacio; Otero, Luis; Fernández, Jonathan; Palacios, Juan José; Martín, Jesús; de la Cruz, Mercedes; Díaz, Caridad; Vicente, Francisca; Reyes, Fernando; García, Luis A; Blanco, Gloria

    2017-02-24

    Two new antibiotics, branimycins B (2) and C (3), were produced by fermentation of the abyssal actinobacterium Pseudonocardia carboxydivorans M-227, isolated from deep seawater of the Avilés submarine Canyon. Their structures were elucidated by HRMS and NMR analyses. These compounds exhibit antibacterial activities against a panel of Gram-positive bacteria, including Corynebacterium urealyticum, Clostridium perfringens, and Micrococcus luteus, and against the Gram-negative bacterium Neisseria meningitidis. Additionally, branimycin B displayed moderate antibacterial activity against other Gram-negative bacteria such as Bacteroides fragilis, Haemophilus influenzae, and Escherichia coli, and branimycin C against the Gram-positive Enterococcus faecalis and methicillin-sensitive and methicillin-resistant Staphylococcus aureus.

  9. Characterization of an Unconventional Rhodopsin from the Freshwater Actinobacterium Rhodoluna lacicola

    PubMed Central

    Keffer, J. L.; Hahn, M. W.

    2015-01-01

    ABSTRACT Rhodopsin-encoding microorganisms are common in many environments. However, knowing that rhodopsin genes are present provides little insight into how the host cells utilize light. The genome of the freshwater actinobacterium Rhodoluna lacicola encodes a rhodopsin of the uncharacterized actinorhodopsin family. We hypothesized that actinorhodopsin was a light-activated proton pump and confirmed this by heterologously expressing R. lacicola actinorhodopsin in retinal-producing Escherichia coli. However, cultures of R. lacicola did not pump protons, even though actinorhodopsin mRNA and protein were both detected. Proton pumping in R. lacicola was induced by providing exogenous retinal, suggesting that the cells lacked the retinal cofactor. We used high-performance liquid chromatography (HPLC) and oxidation of accessory pigments to confirm that R. lacicola does not synthesize retinal. These results suggest that in some organisms, the actinorhodopsin gene is constitutively expressed, but rhodopsin-based light capture may require cofactors obtained from the environment. IMPORTANCE Up to 70% of microbial genomes in some environments are predicted to encode rhodopsins. Because most microbial rhodopsins are light-activated proton pumps, the prevalence of this gene suggests that in some environments, most microorganisms respond to or utilize light energy. Actinorhodopsins were discovered in an analysis of freshwater metagenomic data and subsequently identified in freshwater actinobacterial cultures. We hypothesized that actinorhodopsin from the freshwater actinobacterium Rhodoluna lacicola was a light-activated proton pump and confirmed this by expressing actinorhodopsin in retinal-producing Escherichia coli. Proton pumping in R. lacicola was induced only after both light and retinal were provided, suggesting that the cells lacked the retinal cofactor. These results indicate that photoheterotrophy in this organism and others may require cofactors obtained from the

  10. EMILiO: a fast algorithm for genome-scale strain design.

    PubMed

    Yang, Laurence; Cluett, William R; Mahadevan, Radhakrishnan

    2011-05-01

    Systems-level design of cell metabolism is becoming increasingly important for renewable production of fuels, chemicals, and drugs. Computational models are improving in the accuracy and scope of predictions, but are also growing in complexity. Consequently, efficient and scalable algorithms are increasingly important for strain design. Previous algorithms helped to consolidate the utility of computational modeling in this field. To meet intensifying demands for high-performance strains, both the number and variety of genetic manipulations involved in strain construction are increasing. Existing algorithms have experienced combinatorial increases in computational complexity when applied toward the design of such complex strains. Here, we present EMILiO, a new algorithm that increases the scope of strain design to include reactions with individually optimized fluxes. Unlike existing approaches that would experience an explosion in complexity to solve this problem, we efficiently generated numerous alternate strain designs producing succinate, l-glutamate and l-serine. This was enabled by successive linear programming, a technique new to the area of computational strain design.

  11. Materials design and processings for industrial high-strain-rate superplastic forming

    SciTech Connect

    Hosokawa, H.; Higashi, K.

    2000-07-01

    The optimum materials design in microstructural control could be developed for the high-strain-rate superplastic materials in the industrial scale. In the present work, it is reported that the high-performance-engine pistons with near-net-shape can be fabricated by the superplastic forging technology in the high-strain-rate superplastic PM Al-Si based alloy, which is produced by using this optimum materials design.

  12. Strain shielding inspired re-design of proximal femoral stems for total hip arthroplasty.

    PubMed

    Cilla, Myriam; Checa, Sara; Duda, Georg N

    2017-02-08

    A large number of hip prosthesis with different designs have been developed. However, the influence of hip implant design changes on the strains induced in the bone remains unclear. The purpose of this study is to better understand the mechanics of short stem total hip arthroplasty. Specifically, it investigates whether strain shielding can be avoided by changing implant shape and/or material properties. It is hypothesized that the re-design of existing implant designs can result in further reduction of strain shielding and thus keep bone loss minimal following total hip replacement. Finite element methods were used to compare healthy and implanted models. The local mechanics strains/stresses in the intact and implanted femurs were determined under patient-specific muscle and joint contact forces. Results suggest that small changes in implant geometry and material properties have no major effect on strain shielding. Furthermore, it was found that improvement depends on a dramatic re-design of the original implant design. Whereas the benefit of this strategy of modification of the original geometry of a given short-stemmed hip consists in reduced bone remodeling, care should be taken with regard to long-term bone anchorage and implant fatigue strength. It is also shown that geometrical and material changes have a limited potential in avoiding strain shielding even in short-stemmed implants. Finally, it is suggested that an understanding of the influence of these changes on the strain distribution within the bone can guide in the process of optimizing the current stem designs toward minimal strain shielding effects. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

  13. Flexivirga endophytica sp. nov., an endophytic actinobacterium isolated from a leaf of Sweet Basil.

    PubMed

    Gao, Rui; Liu, Bing-Bing; Yang, Wei; Song, Peng-Fei; Chen, Wei; Salam, Nimaichand; Duan, Yan-Qing; Li, Qing-Qing; Li, Wen-Jun

    2016-09-01

    A Gram-reaction-positive, aerobic, non-motile, irregular coccoid strain, designated YIM 7505T, was isolated from a leaf of Sweet Basil. Phylogenetic analysis on the basis of 16S rRNA gene sequence comparisons revealed that strain YIM 7505T was closely related to Flexivirga alba NBRC 107580T (98.9 % 16S rRNA gene sequence similarity) and formed a robust clade with F. alba NBRC 107580T in the neighbour-joining tree. Optimum growth of strain YIM 7505T was observed at 28-35 °C, pH 7.0 and in the presence of 0-3.0 % NaCl (w/v). The chemotaxonomic profiles of the strain comprised of anteiso-C16 : 0 as the major cellular fatty acid and MK-8(H4) as the respiratory menaquinone. The peptidoglycan of strain YIM 7505T contained serine, alanine, glycine, glutamic acid and lysine. The polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, six unidentified phospholipids, four unidentified glycolipids, an unidentified aminolipid and an unidentified aminophospholipid. The G+C contents of the genomic DNA of strain YIM 7505T was 66.7 mol%. DNA-DNA hybridizations of strain YIM 7505T with F. alba NBRC 107580T gave relatedness values of 50.6±2.2 %. On the basis of the data recorded from the present study, strain YIM 7505T is considered to represent a novel species of the genus Flexivirga, for which the name Flexivirga endophytica sp. nov. is proposed. The type strain is YIM 7505T (=KCTC 39536T=CGMCC 1.15085T).

  14. A Web-Based Platform for Designing Vaccines against Existing and Emerging Strains of Mycobacterium tuberculosis

    PubMed Central

    Dhanda, Sandeep Kumar; Vir, Pooja; Singla, Deepak; Gupta, Sudheer; Kumar, Shailesh

    2016-01-01

    Development of an effective vaccine against drug-resistant Mycobacterium tuberculosis (Mtb) is crucial for saving millions of premature deaths every year due to tuberculosis. This paper describes a web portal developed for assisting researchers in designing vaccines against emerging Mtb strains using traditional and modern approaches. Firstly, we annotated 59 genomes of Mycobacterium species to understand similarity/dissimilarity between tuberculoid, non-tuberculoid and vaccine strains at genome level. Secondly, antigen-based vaccine candidates have been predicted in each Mtb strain. Thirdly, epitopes-based vaccine candidates were predicted/discovered in above antigen-based vaccine candidates that can stimulate all arms of immune system. Finally, a database of predicted vaccine candidates at epitopes as well at antigen level has been developed for above strains. In order to design vaccine against a newly sequenced genome of Mtb strain, server integrates three modules for identification of strain-, antigen-, epitope-specific vaccine candidates. We observed that 103522 unique peptides (9mers) had the potential to induce an antibody response and/or promiscuous binder to MHC alleles and/or have the capability to stimulate T lymphocytes. In summary, this web-portal will be useful for researchers working on designing vaccines against Mtb including drug-resistant strains. Availability: The database is available freely at http://crdd.osdd.net/raghava/mtbveb/. PMID:27096425

  15. Draft Genome Sequence of Microbacterium oleivorans Strain A9, a Bacterium Isolated from Chernobyl Radionuclide-Contaminated Soil.

    PubMed

    Ortet, Philippe; Gallois, Nicolas; Piette, Laurie; Long, Justine; Berthomieu, Catherine; Armengaud, Jean; Barakat, Mohamed; Chapon, Virginie

    2017-04-06

    Here, we present the draft genome sequence of Microbacterium oleivorans strain A9, a uranium-tolerant actinobacterium which has been isolated from radionuclide-contaminated soil from the Chernobyl exclusion zone. It is composed of 22 contigs totaling 2,954,335 bp and contains 2,813 coding DNA sequences, one cluster of rRNA genes, and 45 tRNA genes.

  16. Draft Genome Sequence of Microbacterium oleivorans Strain A9, a Bacterium Isolated from Chernobyl Radionuclide-Contaminated Soil

    PubMed Central

    Gallois, Nicolas; Piette, Laurie; Long, Justine; Berthomieu, Catherine; Armengaud, Jean; Barakat, Mohamed

    2017-01-01

    ABSTRACT Here, we present the draft genome sequence of Microbacterium oleivorans strain A9, a uranium-tolerant actinobacterium which has been isolated from radionuclide-contaminated soil from the Chernobyl exclusion zone. It is composed of 22 contigs totaling 2,954,335 bp and contains 2,813 coding DNA sequences, one cluster of rRNA genes, and 45 tRNA genes. PMID:28385837

  17. Strain response of stretchable micro-electrodes: Controlling sensitivity with serpentine designs and encapsulation

    SciTech Connect

    Gutruf, Philipp; Walia, Sumeet; Nur Ali, Md; Sriram, Sharath E-mail: madhu.bhaskaran@gmail.com; Bhaskaran, Madhu E-mail: madhu.bhaskaran@gmail.com

    2014-01-13

    The functionality of flexible electronics relies on stable performance of thin film micro-electrodes. This letter investigates the behavior of gold thin films on polyimide, a prevalent combination in flexible devices. The dynamic behavior of gold micro-electrodes has been studied by subjecting them to stress while monitoring their resistance in situ. The shape of the electrodes was systematically varied to examine resistive strain sensitivity, while an additional encapsulation was applied to characterize multilayer behavior. The realized designs show remarkable tolerance to repetitive strain, demonstrating that curvature and encapsulation are excellent approaches for minimizing resistive strain sensitivity to enable durable flexible electronics.

  18. Streptomyces lacrimifluminis sp. nov., a novel actinobacterium that produces antibacterial compounds, isolated from soil.

    PubMed

    Zhang, Binglin; Tang, Shukun; Chen, Ximing; Zhang, Ling; Zhang, Gaoseng; Zhang, Wei; Liu, Guangxiu; Chen, Tuo; Li, Shiweng; Dyson, Paul

    2016-12-01

    A novel actinobacterial strain, designated Z1027T, was isolated from a soil sample collected near the Tuotuo River, Qinghai-Tibet Plateau (China). The strain exhibited antibacterial activity against Escherichia coli and Staphylococcus aureus. The taxonomic position of strain Z1027T was determined using a polyphasic approach. The organism had chemotaxonomic and morphological properties consistent with its classification in the genus Streptomyces and formed a distinct phyletic line in the 16S rRNA gene tree, together with Streptomyces turgidiscabies ATCC 700248T (99.19 % similarity), Streptomyces graminilatus JL-6T (98.84 %) and Streptomyces reticuliscabiei CFBP 4531T (98.36 %). The genomic DNA G+C content of strain Z1027T was 74±1 mol%. The DNA-DNA relatedness values between strain Z1027T and Streptomyces turgidiscabies ATCC 700248T and Streptomyces reticuliscabiei CFBP 4531T were 38.5±0.4 and 26.2±1.2 %, respectively, both of them significantly lower than 70 %. Chemotaxonomic data revealed that strain Z1027T possessed MK-9(H6) and MK-9(H8) as the major menaquinones, ll-diaminopimelic acid as the diagnostic diamino acid and galactose as a whole-cell sugar. Diphosphatidylglycerol, phosphatidylethanolamine, phosphatydilinositol and seven other unknown polar lipids were detected; iso-C16 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0 were the major fatty acids. On the basis of these genotypic and phenotypic data, it is proposed that isolate Z1027T (=CGMCC 4.7272T=JCM 31054T) should be classified as the type strain of a novel species of the genus Streptomyces,Streptomyces lacrimifluminis sp. nov.

  19. Design and Testing of the Strain Transducer for Measuring Deformations of Pipelines Operating in the Mining-deformable Ground Environment

    NASA Astrophysics Data System (ADS)

    Gawedzki, Waclaw; Tarnowski, Jerzy

    2015-10-01

    Design and laboratory test results of the strain transducer intended for monitoring and assessing stress states of pipelines sited in mining areas are presented in this paper. This transducer allows measuring strains of pipelines subjected to external forces - being the mining operations effect. Pipeline strains can have a direct influence on a tightness loss and penetration of the transported fluid into the environment. The original strain gauge transducer was proposed for performing measurements of strains. It allows measuring circumferential strains and determining the value and direction of the main longitudinal strain. This strain is determined on the basis of measuring component longitudinal strains originating from axial forces and the resultant bending moment. The main purpose of investigations was the experimental verification of the possibility of applying the strain transducer for measuring strains of polyethylene pipelines. The obtained results of the transducer subjected to influences of tensile and compression forces are presented and tests of relaxation properties of polyethylene are performed.

  20. Design, Evaluation and Experimental Effort Toward Development of a High Strain Composite Wing for Navy Aircraft

    NASA Technical Reports Server (NTRS)

    Bruno, Joseph; Libeskind, Mark

    1990-01-01

    This design development effort addressed significant technical issues concerning the use and benefits of high strain composite wing structures (Epsilon(sub ult) = 6000 micro-in/in) for future Navy aircraft. These issues were concerned primarily with the structural integrity and durability of the innovative design concepts and manufacturing techniques which permitted a 50 percent increase in design ultimate strain level (while maintaining the same fiber/resin system) as well as damage tolerance and survivability requirements. An extensive test effort consisting of a progressive series of coupon and major element tests was an integral part of this development effort, and culminated in the design, fabrication and test of a major full-scale wing box component. The successful completion of the tests demonstrated the structural integrity, durability and benefits of the design. Low energy impact testing followed by fatigue cycling verified the damage tolerance concepts incorporated within the structure. Finally, live fire ballistic testing confirmed the survivability of the design. The potential benefits of combining newer/emerging composite materials and new or previously developed high strain wing design to maximize structural efficiency and reduce fabrication costs was the subject of subsequent preliminary design and experimental evaluation effort.

  1. Effect of nickel titanium file design on the root surface strain and apical microcracks.

    PubMed

    Jamleh, Ahmed; Adorno, Carlos G; Ebihara, Arata; Suda, Hideaki

    2016-04-01

    The aim of this study was to determine the effect of nickel titanium file design on the root surface strain generated and apical microcracks caused during canal shaping. Thirty-three mandibular incisors were distributed into LightSpeed X, FlexMaster and a control group. A strain gauge was fixed apically on the proximal root surface to determine the maximum strain during canal shaping. Except for the control group, all root canals were enlarged to size 50. Images were taken after removing the apical 1 and 2 mm of the root end. Mean maximum strain values and presence of microcracks were statistically compared using the t-test and chi-square test, respectively. During canal shaping, the strain increased cumulatively with mean maximum strains of 808.2 ± 228.8 and 525.1 ± 168.9 microstrain in LightSpeed X and FlexMaster, respectively (P = 0.004). Both systems caused comparable microcracks. Although LightSpeed X produced higher maximum strain, no difference in microcrack development was found between both systems.

  2. Humibacter aquilariae sp. nov., a new actinobacterium isolated from an agarwood chip.

    PubMed

    Lin, Shih-Yao; Hameed, Asif; Liu, You-Cheng; Hsu, Yi-Han; Lai, Wei-An; Hsieh, Yu-Ting; Young, Chiu-Chung

    2016-12-15

    A polyphasic taxonomic approach was used to characterize a presumably novel bacterium, designated strain CC-YTH161T, isolated from an agarwood sample. Strain CC-YTH161T was Gram-staining-positive aerobic rod, which grew at 20-40 ºС, pH 5.0-9.0 and 0-5 % (w/v) salinity. On the basis of 16S rRNA gene sequence analysis, strain CC-YTH161T appeared to belong to the genus Humibacter, and was closely related to Humibacter antri D7-27T (96.6 %) and Humibacter ginsengiterrae DCY60T (96.2 %). The DNA G+C content was 67.0 mol% and the predominant quinone system was menaquinones (MK) 11 and 12. The major cellular fatty acids of the isolate were C15:0, iso C16:0, anteiso C17:0 and C18:1 ω7c/C18:1 ω6c. The polar lipid profile comprised predominant amounts of diphosphatidylglycerol followed by two unidentified co-migrating glycolipids and phosphatidylglycerol in significant amounts. The diagnostic diamino acid was 2,4-diaminobutyric acid. All these features confirmed the placement of the strain CC-YTH161T within the genus Humibacter. On the basis of evidence from this study, strain CC-YTH161T is considered to represent a novel species of the genus Humibacter, for which the name Humibacter aquilariae sp. nov. is proposed. Type strain is CC-YTH161T (=BCRC 80936T =JCM 31199T).

  3. Psychromicrobium silvestre gen. nov., sp. nov., a novel actinobacterium isolated from alpine forest soils.

    PubMed

    Schumann, Peter; Zhang, De-Chao; Franca, Luís; Albuquerque, Luciana; da Costa, Milton S; Margesin, Rosa

    2016-11-21

    Two Gram-stain-variable, non-motile, catalase-positive and cytochrome c oxidase-negative bacteria, designated AK20-18T and AM20-54, were isolated from forest soil samples collected in the Italian Alps. Growth occurred at a temperature range of 5-30 °C, at pH 6-9 and in the presence of 0-5 % (w/v) NaCl. The 16S rRNA gene sequence similarity between strains AK20-18T and AM20-54 was 100 %. Phylogenetic analysis based on 16S rRNA gene sequence showed that AK20-18T had highest 16S rRNA gene sequence similarity with the type strain of Arthrobacter psychrochitiniphilus (96.9 %). The cell-wall peptidoglycan structure of strain AK20-18T was of the type A3alpha L-Lys - L-Thr - L-Ala2 (A11.27). The whole-cell sugars were galactose, ribose and lower amounts of mannose. The major respiratory quinone of the two strains was menaquinone 9(H2) (MK-9 [H2]), whereas MK-10(H2) was a minor component. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and unknown glycolipids. The major cellular fatty acids were anteiso-C15:0, iso-C15:0, iso-C16:0 and anteiso-C17:0. The genomic DNA G+C content was 59.9 mol%. Combined data of phylogenetic, phenotypic and chemotaxonomic analysis demonstrated that strains AK20-18T and AM20-54 represent a novel genus and species, for which the name Psychromicrobium silvestre gen. nov., sp. nov. is proposed. The type strain of Psychromicrobium silvestre is AK20-18T (DSM 102047T = LMG 29369 T).

  4. Novel design of dual-core microstructured fiber with enhanced longitudinal strain sensitivity

    NASA Astrophysics Data System (ADS)

    Szostkiewicz, Lukasz; Tenderenda, T.; Napierala, M.; Szymański, M.; Murawski, M.; Mergo, P.; Lesiak, P.; Marc, P.; Jaroszewicz, L. R.; Nasilowski, T.

    2014-05-01

    Constantly refined technology of manufacturing increasingly complex photonic crystal fibers (PCF) leads to new optical fiber sensor concepts. The ways of enhancing the influence of external factors (such as hydrostatic pressure, temperature, acceleration) on the fiber propagating conditions are commonly investigated in literature. On the other hand longitudinal strain analysis, due to the calculation difficulties caused by the three dimensional computation, are somehow neglected. In this paper we show results of such a 3D numerical simulation and report methods of tuning the fiber strain sensitivity by changing the fiber microstructure and core doping level. Furthermore our approach allows to control whether the modes' effective refractive index is increasing or decreasing with strain, with the possibility of achieving zero strain sensitivity with specific fiber geometries. The presented numerical analysis is compared with experimental results of the fabricated fibers characterization. Basing on the aforementioned methodology we propose a novel dual-core fiber design with significantly increased sensitivity to longitudinal strain for optical fiber sensor applications. Furthermore the reported fiber satisfies all conditions necessary for commercial applications like good mode matching with standard single-mode fiber, low confinement loss and ease of manufacturing with the stack-and-draw technique. Such fiber may serve as an integrated Mach-Zehnder interferometer when highly coherent source is used. With the optimization of single mode transmission to 850 nm, we propose a VCSEL source to be used in order to achieve a low-cost, reliable and compact strain sensing transducer.

  5. Strain-Based Design Methodology of Large Diameter Grade X80 Linepipe

    SciTech Connect

    Lower, Mark D.

    2014-04-01

    Continuous growth in energy demand is driving oil and natural gas production to areas that are often located far from major markets where the terrain is prone to earthquakes, landslides, and other types of ground motion. Transmission pipelines that cross this type of terrain can experience large longitudinal strains and plastic circumferential elongation as the pipeline experiences alignment changes resulting from differential ground movement. Such displacements can potentially impact pipeline safety by adversely affecting structural capacity and leak tight integrity of the linepipe steel. Planning for new long-distance transmission pipelines usually involves consideration of higher strength linepipe steels because their use allows pipeline operators to reduce the overall cost of pipeline construction and increase pipeline throughput by increasing the operating pressure. The design trend for new pipelines in areas prone to ground movement has evolved over the last 10 years from a stress-based design approach to a strain-based design (SBD) approach to further realize the cost benefits from using higher strength linepipe steels. This report presents an overview of SBD for pipelines subjected to large longitudinal strain and high internal pressure with emphasis on the tensile strain capacity of high-strength microalloyed linepipe steel. The technical basis for this report involved engineering analysis and examination of the mechanical behavior of Grade X80 linepipe steel in both the longitudinal and circumferential directions. Testing was conducted to assess effects on material processing including as-rolled, expanded, and heat treatment processing intended to simulate coating application. Elastic-plastic and low-cycle fatigue analyses were also performed with varying internal pressures. Proposed SBD models discussed in this report are based on classical plasticity theory and account for material anisotropy, triaxial strain, and microstructural damage effects

  6. Large-scale bi-level strain design approaches and mixed-integer programming solution techniques.

    PubMed

    Kim, Joonhoon; Reed, Jennifer L; Maravelias, Christos T

    2011-01-01

    The use of computational models in metabolic engineering has been increasing as more genome-scale metabolic models and computational approaches become available. Various computational approaches have been developed to predict how genetic perturbations affect metabolic behavior at a systems level, and have been successfully used to engineer microbial strains with improved primary or secondary metabolite production. However, identification of metabolic engineering strategies involving a large number of perturbations is currently limited by computational resources due to the size of genome-scale models and the combinatorial nature of the problem. In this study, we present (i) two new bi-level strain design approaches using mixed-integer programming (MIP), and (ii) general solution techniques that improve the performance of MIP-based bi-level approaches. The first approach (SimOptStrain) simultaneously considers gene deletion and non-native reaction addition, while the second approach (BiMOMA) uses minimization of metabolic adjustment to predict knockout behavior in a MIP-based bi-level problem for the first time. Our general MIP solution techniques significantly reduced the CPU times needed to find optimal strategies when applied to an existing strain design approach (OptORF) (e.g., from ∼10 days to ∼5 minutes for metabolic engineering strategies with 4 gene deletions), and identified strategies for producing compounds where previous studies could not (e.g., malate and serine). Additionally, we found novel strategies using SimOptStrain with higher predicted production levels (for succinate and glycerol) than could have been found using an existing approach that considers network additions and deletions in sequential steps rather than simultaneously. Finally, using BiMOMA we found novel strategies involving large numbers of modifications (for pyruvate and glutamate), which sequential search and genetic algorithms were unable to find. The approaches and solution

  7. Structural synthetic biotechnology: from molecular structure to predictable design for industrial strain development.

    PubMed

    Chen, Zhen; Wilmanns, Matthias; Zeng, An-Ping

    2010-10-01

    The future of industrial biotechnology requires efficient development of highly productive and robust strains of microorganisms. Present praxis of strain development cannot adequately fulfill this requirement, primarily owing to the inability to control reactions precisely at a molecular level, or to predict reliably the behavior of cells upon perturbation. Recent developments in two areas of biology are changing the situation rapidly: structural biology has revealed details about enzymes and associated bioreactions at an atomic level; and synthetic biology has provided tools to design and assemble precisely controllable modules for re-programming cellular metabolic circuitry. However, because of different emphases, to date, these two areas have developed separately. A linkage between them is desirable to harness their concerted potential. We therefore propose structural synthetic biotechnology as a new field in biotechnology, specifically for application to the development of industrial microbial strains.

  8. Rhodococcus yunnanensis sp. nov., a mesophilic actinobacterium isolated from forest soil.

    PubMed

    Zhang, Yu-Qin; Li, Wen-Jun; Kroppenstedt, Reiner M; Kim, Chang-Jin; Chen, Guo-Zhong; Park, Dong-Jin; Xu, Li-Hua; Jiang, Cheng-Lin

    2005-05-01

    A Gram-positive, aerobic, non-motile, mesophilic strain, designated YIM 70056(T), was isolated from a forest soil sample in Yunnan Province, China. Phylogenetic analysis based on 16S rRNA gene sequences revealed that this isolate had less than 97.0 % similarity to any Rhodococcus species with validly published names, with the exception of Rhodococcus fascians (DSM 20669(T)), which was found to be its closest neighbour (98.9 % similarity). Chemotaxonomic data, including peptidoglycan type, diagnostic sugar compositions, fatty acid profiles, menaquinones, polar lipids and mycolic acids, were determined for this isolate; the results supported the affiliation of strain YIM 70056(T) to the genus Rhodococcus. The DNA G + C content was 63.5 mol%. The results of DNA-DNA hybridization with R. fascians DSM 20669(T), in combination with chemotaxonomic and physiological data, demonstrated that isolate YIM 70056(T) represents a novel Rhodococcus species, for which the name Rhodococcus yunnanensis sp. nov. is proposed, with YIM 70056(T) (=CCTCC AA 204007(T) = KCTC 19021(T) = DSM 44837(T)) as the type strain.

  9. Migration and strains induced by different designs of force-closed stems for THA☆

    PubMed Central

    Griza, Sandro; Gomes, Luiz Sérgio Marcelino; Cervieri, André; Strohaecker, Telmo Roberto

    2015-01-01

    Objectives Subtle differences in stem design can result in different mechanical responses of the total hip arthroplasty. Tests measuring migration of the stem relative to the femur, as well as the strains in the cement mantle and on the femur can detect different mechanical behavior between stems. Methods In this article, conical, double and triple tapered stems were implanted in composite femurs and subjected to static and cyclic loads. Stems differed mainly on taper angle, calcar radius and proximal stiffness. Stem migration and strains on the femur and in the cement mantle were achieved. Results Significant differences (p < 0.05) were noted in the permanent rotation between double and triple tapers, in the strains on the proximal medial femur between triple and both conical and double tapers, and in the strains on the lateral proximal femur between double tapers and both conical and triple tapers. Conclusion The proposed mechanical tests were able to detect significant differences in the behavior of these resembling stems. Stem proximal stiffness and the calcar radius of the stem influence its rotational stability and the strain transmission to the femur. PMID:27218081

  10. Multiscale Strain Analysis of Tissue Equivalents Using a Custom-Designed Biaxial Testing Device

    PubMed Central

    Bell, B.J.; Nauman, E.; Voytik-Harbin, S.L.

    2012-01-01

    Mechanical signals transferred between a cell and its extracellular matrix play an important role in regulating fundamental cell behavior. To further define the complex mechanical interactions between cells and matrix from a multiscale perspective, a biaxial testing device was designed and built. Finite element analysis was used to optimize the cruciform specimen geometry so that stresses within the central region were concentrated and homogenous while minimizing shear and grip effects. This system was used to apply an equibiaxial loading and unloading regimen to fibroblast-seeded tissue equivalents. Digital image correlation and spot tracking were used to calculate three-dimensional strains and associated strain transfer ratios at macro (construct), meso, matrix (collagen fibril), cell (mitochondria), and nuclear levels. At meso and matrix levels, strains in the 1- and 2-direction were statistically similar throughout the loading-unloading cycle. Interestingly, a significant amplification of cellular and nuclear strains was observed in the direction perpendicular to the cell axis. Findings indicate that strain transfer is dependent upon local anisotropies generated by the cell-matrix force balance. Such multiscale approaches to tissue mechanics will assist in advancement of modern biomechanical theories as well as development and optimization of preconditioning regimens for functional engineered tissue constructs. PMID:22455913

  11. Simplified sensor design for temperature-strain discrimination using fiber Bragg gratings embedded in laminated composites

    NASA Astrophysics Data System (ADS)

    Rodriguez-Cobo, L.; Marques, A. T.; Lopez-Higuera, J. M.; Santos, J. L.; Frazão, O.

    2013-05-01

    Several easy-to-manufacture designs based on a pair of Fiber Bragg Gratings structure embedded in Carbon Fiber Reinforced Plastic (CFRP) have been explored. These smart composites can be used for strain and temperature discrimination. A Finite Elements Analysis and Matlab software were used to study the mechanical responses and its optical behaviors. The results exhibited different sensitivity and using a matrix method it is possible to compensate the thermal drift in a real application keeping a simple manufacture process.

  12. Genomic Libraries and a Host Strain Designed for Highly Efficient Two-Hybrid Selection in Yeast

    PubMed Central

    James, P.; Halladay, J.; Craig, E. A.

    1996-01-01

    The two-hybrid system is a powerful technique for detecting protein-protein interactions that utilizes the well-developed molecular genetics of the yeast Saccharomyces cerevisiae. However, the full potential of this technique has not been realized due to limitations imposed by the components available for use in the system. These limitations include unwieldy plasmid vectors, incomplete or poorly designed two-hybrid libraries, and host strains that result in the selection of large numbers of false positives. We have used a novel multienzyme approach to generate a set of highly representative genomic libraries from S. cerevisiae. In addition, a unique host strain was created that contains three easily assayed reporter genes, each under the control of a different inducible promoter. This host strain is extremely sensitive to weak interactions and eliminates nearly all false positives using simple plate assays. Improved vectors were also constructed that simplify the construction of the gene fusions necessary for the two-hybrid system. Our analysis indicates that the libraries and host strain provide significant improvements in both the number of interacting clones identified and the efficiency of two-hybrid selections. PMID:8978031

  13. Complete Genome Sequence of pAP13, a Large Linear Plasmid of a Brevibacterium Strain Isolated from a Saline Lake at 4,200 Meters above Sea Level in Argentina

    PubMed Central

    Schuldes, Jörg; Thürmer, Andrea; Farias, María E.; Daniel, Rolf; Meinhardt, Friedhelm

    2013-01-01

    pAP13 is an 89-kb linear plasmid hosted by Brevibacterium sp. strain Ap13, an actinobacterium isolated from the feces of a flamingo from an extremely high-altitude lake in Argentina. Because of the ecological importance of the genus Brevibacterium, the absolute lack of information concerning Brevibacterium linear plasmids, and the possible ecological significance of this unusual plasmid, pAP13 was completely sequenced, including the inversely oriented termini. PMID:24285657

  14. Design and Validation of Equiaxial Mechanical Strain Platform, EQUicycler, for 3D Tissue Engineered Constructs.

    PubMed

    Elsaadany, Mostafa; Harris, Matthew; Yildirim-Ayan, Eda

    2017-01-01

    It is crucial to replicate the micromechanical milieu of native tissues to achieve efficacious tissue engineering and regenerative therapy. In this study, we introduced an innovative loading platform, EQUicycler, that utilizes a simple, yet effective, and well-controlled mechanism to apply physiologically relevant homogenous mechanical equiaxial strain on three-dimensional cell-embedded tissue scaffolds. The design of EQUicycler ensured elimination of gripping effects through the use of biologically compatible silicone posts for direct transfer of the mechanical load to the scaffolds. Finite Element Modeling (FEM) was created to understand and to quantify how much applied global strain was transferred from the loading mechanism to the tissue constructs. In vitro studies were conducted on various cell lines associated with tissues exposed to equiaxial mechanical loading in their native environment. In vitro results demonstrated that EQUicycler was effective in maintaining and promoting the viability of different musculoskeletal cell lines and upregulating early differentiation of osteoprogenitor cells. By utilizing EQUicycler, collagen fibers of the constructs were actively remodeled. Residing cells within the collagen construct elongated and aligned with strain direction upon mechanical loading. EQUicycler can provide an efficient and cost-effective tool to conduct mechanistic studies for tissue engineered constructs designed for tissue systems under mechanical loading in vivo.

  15. Design and Validation of Equiaxial Mechanical Strain Platform, EQUicycler, for 3D Tissue Engineered Constructs

    PubMed Central

    Harris, Matthew

    2017-01-01

    It is crucial to replicate the micromechanical milieu of native tissues to achieve efficacious tissue engineering and regenerative therapy. In this study, we introduced an innovative loading platform, EQUicycler, that utilizes a simple, yet effective, and well-controlled mechanism to apply physiologically relevant homogenous mechanical equiaxial strain on three-dimensional cell-embedded tissue scaffolds. The design of EQUicycler ensured elimination of gripping effects through the use of biologically compatible silicone posts for direct transfer of the mechanical load to the scaffolds. Finite Element Modeling (FEM) was created to understand and to quantify how much applied global strain was transferred from the loading mechanism to the tissue constructs. In vitro studies were conducted on various cell lines associated with tissues exposed to equiaxial mechanical loading in their native environment. In vitro results demonstrated that EQUicycler was effective in maintaining and promoting the viability of different musculoskeletal cell lines and upregulating early differentiation of osteoprogenitor cells. By utilizing EQUicycler, collagen fibers of the constructs were actively remodeled. Residing cells within the collagen construct elongated and aligned with strain direction upon mechanical loading. EQUicycler can provide an efficient and cost-effective tool to conduct mechanistic studies for tissue engineered constructs designed for tissue systems under mechanical loading in vivo. PMID:28168197

  16. Design of atomic step networks on Si(111) through strain distribution control

    NASA Astrophysics Data System (ADS)

    Omi, Hiroo; Homma, Yoshikazu; Ogino, Toshio; Stoyanov, Stoyan; Tonchev, Vesselin

    2004-01-01

    We propose an alternative method to control atomic step networks on silicon for future wafer-scale integration of self-assembling nanostructures. The method is the strain-distribution-control method that we have recently proposed in [H. Omi, D. J. Bottomley, and T. Ogino, Appl. Phys. Lett. 80, 1073 (2002)], which we apply here to design atomic step networks on vicinal Si(111) wafer. Si(111) with its strain patterned by buried silicon oxide inclusions was annealed at 1230 °C in ultrahigh vacuum and observed by in situ secondary electron microscopy and ex situ atomic force microscopy. The images show that the method enables us to create the desired arrays of atomic step networks on an arbitrary area of planar silicon wafer. The arrays remain stable during the 1230 °C annealing.

  17. How Many Peripheral Solder Joints in a Surface Mounted Design Experience Inelastic Strains?

    NASA Astrophysics Data System (ADS)

    Suhir, E.; Yi, S.; Ghaffarian, R.

    2017-01-01

    It has been established that it is the peripheral solder joints that are the most vulnerable in the ball-grid-array (BGA) and column-grid-array (CGA) designs and most often fail. As far as the long-term reliability of a soldered microelectronics assembly as a whole is concerned, it makes a difference, if just one or more peripheral joints experience inelastic strains. It is clear that the low cycle fatigue lifetime of the solder system is inversely proportional to the number of joints that simultaneously experience inelastic strains. A simple and physically meaningful analytical expression (formula) is obtained for the prediction, at the design stage, of the number of such joints, if any, for the given effective thermal expansion (contraction) mismatch of the package and PCB; materials and geometrical characteristics of the package/PCB assembly; package size; and, of course, the level of the yield stress in the solder material. The suggested formula can be used to determine if the inelastic strains in the solder material could be avoided by the proper selection of the above characteristics and, if not, how many peripheral joints are expected to simultaneously experience inelastic strains. The general concept is illustrated by a numerical example carried out for a typical BGA package. The suggested analytical model (formula) is applicable to any soldered microelectronics assembly. The roles of other important factors, such as, e.g., solder material anisotropy, grain size, and their random orientation within a joint, are viewed in this analysis as less important factors than the level of the interfacial stress. The roles of these factors will be accounted for in future work and considered, in addition to the location of the joint, in a more complicated, more sophisticated, and more comprehensive reliability/fatigue model.

  18. How Many Peripheral Solder Joints in a Surface Mounted Design Experience Inelastic Strains?

    NASA Astrophysics Data System (ADS)

    Suhir, E.; Yi, S.; Ghaffarian, R.

    2017-03-01

    It has been established that it is the peripheral solder joints that are the most vulnerable in the ball-grid-array (BGA) and column-grid-array (CGA) designs and most often fail. As far as the long-term reliability of a soldered microelectronics assembly as a whole is concerned, it makes a difference, if just one or more peripheral joints experience inelastic strains. It is clear that the low cycle fatigue lifetime of the solder system is inversely proportional to the number of joints that simultaneously experience inelastic strains. A simple and physically meaningful analytical expression (formula) is obtained for the prediction, at the design stage, of the number of such joints, if any, for the given effective thermal expansion (contraction) mismatch of the package and PCB; materials and geometrical characteristics of the package/PCB assembly; package size; and, of course, the level of the yield stress in the solder material. The suggested formula can be used to determine if the inelastic strains in the solder material could be avoided by the proper selection of the above characteristics and, if not, how many peripheral joints are expected to simultaneously experience inelastic strains. The general concept is illustrated by a numerical example carried out for a typical BGA package. The suggested analytical model (formula) is applicable to any soldered microelectronics assembly. The roles of other important factors, such as, e.g., solder material anisotropy, grain size, and their random orientation within a joint, are viewed in this analysis as less important factors than the level of the interfacial stress. The roles of these factors will be accounted for in future work and considered, in addition to the location of the joint, in a more complicated, more sophisticated, and more comprehensive reliability/fatigue model.

  19. Design of homo-organic acid producing strains using multi-objective optimization.

    PubMed

    Kim, Tae Yong; Park, Jong Myoung; Kim, Hyun Uk; Cho, Kwang Myung; Lee, Sang Yup

    2015-03-01

    Production of homo-organic acids without byproducts is an important challenge in bioprocess engineering to minimize operation cost for separation processes. In this study, we used multi-objective optimization to design Escherichia coli strains with the goals of maximally producing target organic acids, while maintaining sufficiently high growth rate and minimizing the secretion of undesired byproducts. Homo-productions of acetic, lactic and succinic acids were targeted as examples. Engineered E. coli strains capable of producing homo-acetic and homo-lactic acids could be developed by taking this systems approach for the minimal identification of gene knockout targets. Also, failure to predict effective gene knockout targets for the homo-succinic acid production suggests that the multi-objective optimization is useful in assessing the suitability of a microorganism as a host strain for the production of a homo-organic acid. The systems metabolic engineering-based approach reported here should be applicable to the production of other industrially important organic acids.

  20. A strain-absorbing design for tissue-machine interfaces using a tunable adhesive gel.

    PubMed

    Lee, Sungwon; Inoue, Yusuke; Kim, Dongmin; Reuveny, Amir; Kuribara, Kazunori; Yokota, Tomoyuki; Reeder, Jonathan; Sekino, Masaki; Sekitani, Tsuyoshi; Abe, Yusuke; Someya, Takao

    2014-12-19

    To measure electrophysiological signals from the human body, it is essential to establish stable, gentle and nonallergic contacts between the targeted biological tissue and the electrical probes. However, it is difficult to form a stable interface between the two for long periods, especially when the surface of the biological tissue is wet and/or the tissue exhibits motion. Here we resolve this difficulty by designing and fabricating smart, stress-absorbing electronic devices that can adhere to wet and complex tissue surfaces and allow for reliable, long-term measurements of vital signals. We demonstrate a multielectrode array, which can be attached to the surface of a rat heart, resulting in good conformal contact for more than 3 h. Furthermore, we demonstrate arrays of highly sensitive, stretchable strain sensors using a similar design. Ultra-flexible electronics with enhanced adhesion to tissue could enable future applications in chronic in vivo monitoring of biological signals.

  1. A strain-absorbing design for tissue-machine interfaces using a tunable adhesive gel

    NASA Astrophysics Data System (ADS)

    Lee, Sungwon; Inoue, Yusuke; Kim, Dongmin; Reuveny, Amir; Kuribara, Kazunori; Yokota, Tomoyuki; Reeder, Jonathan; Sekino, Masaki; Sekitani, Tsuyoshi; Abe, Yusuke; Someya, Takao

    2014-12-01

    To measure electrophysiological signals from the human body, it is essential to establish stable, gentle and nonallergic contacts between the targeted biological tissue and the electrical probes. However, it is difficult to form a stable interface between the two for long periods, especially when the surface of the biological tissue is wet and/or the tissue exhibits motion. Here we resolve this difficulty by designing and fabricating smart, stress-absorbing electronic devices that can adhere to wet and complex tissue surfaces and allow for reliable, long-term measurements of vital signals. We demonstrate a multielectrode array, which can be attached to the surface of a rat heart, resulting in good conformal contact for more than 3 h. Furthermore, we demonstrate arrays of highly sensitive, stretchable strain sensors using a similar design. Ultra-flexible electronics with enhanced adhesion to tissue could enable future applications in chronic in vivo monitoring of biological signals.

  2. Pathobiology of aging mice and GEM: background strains and experimental design.

    PubMed

    Brayton, C F; Treuting, P M; Ward, J M

    2012-01-01

    The use of induced and spontaneous mutant mice and genetically engineered mice (and combinations thereof) to study cancers and other aging phenotypes to advance improved functional human life spans will involve studies of aging mice. Genetic background contributes to pathology phenotypes and to causes of death as well as to longevity. Increased recognition of expected phenotypes, experimental variables that influence phenotypes and research outcomes, and experimental design options and rationales can maximize the utility of genetically engineered mice (GEM) models to translational research on aging. This review aims to provide resources to enhance the design and practice of chronic and longevity studies involving GEM. C57BL6, 129, and FVB/N strains are emphasized because of their widespread use in the generation of knockout, transgenic, and conditional mutant GEM. Resources are included also for pathology of other inbred strain families, including A, AKR, BALB/c, C3H, C57L, C58, CBA, DBA, GR, NOD.scid, SAMP, and SJL/J, and non-inbred mice, including 4WC, AB6F1, Ames dwarf, B6, 129, B6C3F1, BALB/c,129, Het3, nude, SENCAR, and several Swiss stocks. Experimental strategies for long-term cross-sectional and longitudinal studies to assess causes of or contributors to death, disease burden, spectrum of pathology phenotypes, longevity, and functional healthy life spans (health spans) are compared and discussed.

  3. Design of Stress-Strain Measuring System for Bulldozing Plate Based on Virtual Instrument Technology

    NASA Astrophysics Data System (ADS)

    Xu, S. C.; Li, J. Q.; Zhang, R.

    2006-10-01

    Soil is a kind of discrete, multiphase compound that is composed of soil particles, liquid and air. When soil is disturbed by bulldozing plate, the mechanical behavior of the soil will become very complex. Based on the law of action and reaction, the dynamic mechanical behavior of disturbed soil was indirectly analyzed by measuring and studying the forces on the bulldozing plate by soil currently, so a stress-strain virtual measuring system for bulldozing plate, which was designed by the graphical programming language DASYLab, was used to measure the horizontal force Fz acting on the bulldozing plate. In addition, during the course of design, the experimental complexities and the interferential factors influencing on signal logging were analyzed when bulldozing plate worked, so the anti-jamming methods of hardware and software technology were adopted correlatively. In the end, the horizontal force Fz was analyzed with Error Theory, the result shown that the quantificational analysis of Fz were identical to the qualitative results of soil well, and the error of the whole test system is under 5 percent, so the tress-strain virtual measuring system was stable and credible.

  4. Rudaeicoccus suwonensis gen. nov., sp. nov., an actinobacterium isolated from the epidermal tissue of a root of a Phalaenopsis orchid.

    PubMed

    Kim, Soo-Jin; Jang, Yun-Hee; Ahn, Jae-Hyung; Weon, Hang-Yeon; Schumann, Peter; Chun, Se-Chul; Kwon, Soon-Wo; Kim, Wan-Gyu

    2013-04-01

    A bacterial strain, designated HOR6-4(T), was isolated from the epidermal tissue of a root of a Phalaenopsis orchid. Strain HOR6-4(T) was characterized using a polyphasic approach. The cells were aerobic, Gram-stain-positive, non-motile coccoids. Phylogenetic analysis of its 16S rRNA gene sequence revealed a clear affiliation with the family Dermacoccaceae. Strain HOR6-4(T) showed relatively low 16S rRNA gene sequence similarity (below 95.9 %) to type strains of species with validly published names, showing the highest sequence similarities to the type strains of Flexivirga alba (95.8 %) and Yimella lutea (95.5 %). The DNA G+C content of strain HOR6-4(T) was 64.7 mol%. Strain HOR6-4(T) had anteiso-C17 : 0 (19.3 %), 10-methyl C18 : 0 (tuberculostearic acid; 13.5 %) and 10-methyl C17 : 0 (11.7 %) as the major fatty acids and contained MK-8(H4) and MK-8(H6) as the predominant quinones. Polar lipids were diphosphatidylglycerol, phosphatidylinositol, three aminophospholipids, two phospholipids and an aminolipid. The peptidoglycan type was A4α, with an L-Lys-L-Thr-D-Glu interpeptide bridge with a glycine residue bound to the alpha-carboxyl group of D-Glu in position 2 of the peptide subunit. Mycolic acids were not present. On the basis of comparative analysis of phenotypic and phylogenetic traits, strain HOR6-4(T) is considered to represent a novel species in a new genus in the family Dermacoccaceae, for which the name Rudaeicoccus suwonensis gen. nov., sp. nov. is proposed. The type strain of Rudaeicoccus suwonensis is HOR6-4(T) ( = KACC 12637(T)  = DSM 19560(T)).

  5. Design of a Probe for Strain Sensitivity Studies of Critical Current Densities in SC Wires and Tapes

    SciTech Connect

    Dhanaraj, N.; Barzi, E.; Turrioni, D.; Rusy, A.; Lombardo, V.; /Fermilab

    2011-07-01

    The design of a variable-temperature probe used to perform strain sensitivity measurements on LTS wires and HTS wires and tapes is described. The measurements are intended to be performed at liquid helium temperatures (4.2 K). The wire or tape to be measured is wound and soldered on to a helical spring device, which is fixed at one end and subjected to a torque at the free end. The design goal is to be able to achieve {+-} 0.8 % strain in the wire and tape. The probe is designed to carry a current of 2000A.

  6. Flux control-based design of furfural-resistance strains of Saccharomyces cerevisiae for lignocellulosic biorefinery.

    PubMed

    Unrean, Pornkamol

    2016-12-26

    We have previously developed a dynamic flux balance analysis of Saccharomyces cerevisiae for elucidation of genome-wide flux response to furfural perturbation (Unrean and Franzen, Biotechnol J 10(8):1248-1258, 2015). Herein, the dynamic flux distributions were analyzed by flux control analysis to identify target overexpressed genes for improved yeast robustness against furfural. The flux control coefficient (FCC) identified overexpressing isocitrate dehydrogenase (IDH1), a rate-controlling flux for ethanol fermentation, and dicarboxylate carrier (DIC1), a limiting flux for cell growth, as keys of furfural-resistance phenotype. Consistent with the model prediction, strain characterization showed 1.2- and 2.0-fold improvement in ethanol synthesis and furfural detoxification rates, respectively, by IDH1 overexpressed mutant compared to the control. DIC1 overexpressed mutant grew at 1.3-fold faster and reduced furfural at 1.4-fold faster than the control under the furfural challenge. This study hence demonstrated the FCC-based approach as an effective tool for guiding the design of robust yeast strains.

  7. Enhanced production of thermostable laccases from a native strain of Pycnoporus sanguineus using central composite design.

    PubMed

    Ramírez-Cavazos, Leticia I; Junghanns, Charles; Nair, Rakesh; Cárdenas-Chávez, Diana L; Hernández-Luna, Carlos; Agathos, Spiros N; Parra, Roberto

    2014-04-01

    The production of thermostable laccases from a native strain of the white-rot fungus Pycnoporus sanguineus isolated in Mexico was enhanced by testing different media and a combination of inducers including copper sulfate (CuSO4). The best conditions obtained from screening experiments in shaken flasks using tomato juice, CuSO4, and soybean oil were integrated in an experimental design. Enhanced levels of tomato juice as the medium, CuSO4 and soybean oil as inducers (36.8% (v/v), 3 mmol/L, and 1% (v/v), respectively) were determined for 10 L stirred tank bioreactor runs. This combination resulted in laccase titer of 143,000 IU/L (2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid), pH 3.0), which represents the highest activity so far reported for P. sanguineus in a 10-L fermentor. Other interesting media resulting from the screening included glucose-bactopeptone which increased laccase activity up to 20,000 IU/L, whereas the inducers Acid Blue 62 and Reactive Blue 19 enhanced enzyme production in this medium 10 times. Based on a partial characterization, the laccases of this strain are especially promising in terms of thermostability (half-life of 6.1 h at 60 °C) and activity titers.

  8. Enhanced production of thermostable laccases from a native strain of Pycnoporus sanguineus using central composite design*

    PubMed Central

    Ramírez-Cavazos, Leticia I.; Junghanns, Charles; Nair, Rakesh; Cárdenas-Chávez, Diana L.; Hernández-Luna, Carlos; Agathos, Spiros N.; Parra, Roberto

    2014-01-01

    The production of thermostable laccases from a native strain of the white-rot fungus Pycnoporus sanguineus isolated in Mexico was enhanced by testing different media and a combination of inducers including copper sulfate (CuSO4). The best conditions obtained from screening experiments in shaken flasks using tomato juice, CuSO4, and soybean oil were integrated in an experimental design. Enhanced levels of tomato juice as the medium, CuSO4 and soybean oil as inducers (36.8% (v/v), 3 mmol/L, and 1% (v/v), respectively) were determined for 10 L stirred tank bioreactor runs. This combination resulted in laccase titer of 143 000 IU/L (2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid), pH 3.0), which represents the highest activity so far reported for P. sanguineus in a 10-L fermentor. Other interesting media resulting from the screening included glucose-bactopeptone which increased laccase activity up to 20 000 IU/L, whereas the inducers Acid Blue 62 and Reactive Blue 19 enhanced enzyme production in this medium 10 times. Based on a partial characterization, the laccases of this strain are especially promising in terms of thermostability (half-life of 6.1 h at 60 °C) and activity titers. PMID:24711355

  9. Improved vertical optical fiber borehole strainmeter design for measuring Earth strain.

    PubMed

    DeWolf, Scott; Wyatt, Frank K; Zumberge, Mark A; Hatfield, William

    2015-11-01

    Fiber-based interferometers provide the means to sense very small displacements over long baselines, and have the advantage of being nearly completely passive in their operation, making them particularly well suited for geophysical applications. A new 250 m, interferometric vertical borehole strainmeter has been developed based completely on passive optical components. Details of the design and deployment at the Piñon Flat Observatory are presented. Power spectra show an intertidal noise level of -130 dB (re. 1 ϵ(2)/Hz), consistent within 1-3 dB between redundant components. Examination of its response to Earth tides and earthquakes relative to the areal strain recorded by an orthogonal pair of collocated, 730 m horizontal laser strainmeters yield a Poisson's ratio for local near surface material of 0.25 that is consistent with previous results.

  10. Isoptericola rhizophila sp. nov., a novel actinobacterium isolated from rhizosphere soil.

    PubMed

    Kaur, Navjot; Rajendran, Mathan Kumar; Kaur, Gurwinder; Shanmugam, Mayilraj

    2014-08-01

    A Gram-positive, yellow pigmented strain, BKS 3-46(T) was isolated from a soil sample collected from the rhizosphere of Ficus benghalensis (banyan tree) in Bhitarkanika mangrove forest, in the Indian state of Odisha, and subjected to polyphasic taxonomic study. The 16S rRNA gene sequence of the strain was determined and the sequence analysis showed that strain BKS 3-46(T) should be assigned to the genus Isoptericola. The chemotaxonomic data supported this taxonomic placement i.e. presence of menaquinone MK-9(H4); major fatty acids anteiso C15:0 and iso-C15:0; and phosphatidylglycerol, diphosphatidylglycerol and phosphatidylinositol (PI) as major polar lipids. Further phylogenetic analysis of the 16S rRNA gene sequence confirmed that the strain BKS 3-46(T) belongs to the genus Isoptericola and is closely related to Isoptericola halotolerans MTCC 11265(T) (98.6 %) followed by Isoptericola nanjingensis MTCC 11633(T) (98.4 %) and Isoptericola chiayiensis MTCC 11634(T) (98.1 %). However, the DNA-DNA hybridization values obtained between strain BKS 3-46(T) and other related strains were well below the threshold that is required for the proposal of a novel species. The G+C content of the genomic DNA was determined to be 70.4 mol%. The phenotypic and genotypic data showed that the strain BKS 3-46(T) merits the recognition as a representative of a novel species of the genus Isoptericola. It is proposed that the isolate should be classified in the genus Isoptericola as a novel species, Isoptericola rhizophila sp. nov. The type strain is BKS 3-46(T) (=MTCC 11080(T)=JCM 19252(T)).

  11. Rhodococcus kroppenstedtii sp. nov., a novel actinobacterium isolated from a cold desert of the Himalayas, India.

    PubMed

    Mayilraj, S; Krishnamurthi, S; Saha, P; Saini, H S

    2006-05-01

    The taxonomic position of an actinomycete, strain K07-23T, isolated from a cold desert of the Himalayas, India, was established by a polyphasic approach. The strain exhibited phenotypic characters that were typical of the genus Rhodococcus. 16S rRNA gene sequence (1467 bases) comparisons confirmed that strain K07-23T belongs to the genus Rhodococcus. 16S rRNA sequence similarity studies showed that the isolate is very closely related to Nocardia corynebacterioides DSM 20151T (98.6 %), which has been recently reclassified as Rhodococcus corynebacterioides. It showed 94.4-96.6 % sequence similarity with other species of the genus Rhodococcus. However, genomic relatedness between strain K07-23T and R. corynebacterioides as revealed by DNA-DNA hybridization was low (62 %). Based on polyphasic analysis, strain K07-23T could be clearly distinguished from other species. It is proposed that strain K07-23T (=MTCC 6634T=DSM 44908T=JCM 13011T) represents a novel species of Rhodococcus, Rhodococcus kroppenstedtii sp. nov.

  12. Succinate Overproduction: A Case Study of Computational Strain Design Using a Comprehensive Escherichia coli Kinetic Model.

    PubMed

    Khodayari, Ali; Chowdhury, Anupam; Maranas, Costas D

    2014-01-01

    Computational strain-design prediction accuracy has been the focus for many recent efforts through the selective integration of kinetic information into metabolic models. In general, kinetic model prediction quality is determined by the range and scope of genetic and/or environmental perturbations used during parameterization. In this effort, we apply the k-OptForce procedure on a kinetic model of E. coli core metabolism constructed using the Ensemble Modeling (EM) method and parameterized using multiple mutant strains data under aerobic respiration with glucose as the carbon source. Minimal interventions are identified that improve succinate yield under both aerobic and anaerobic conditions to test the fidelity of model predictions under both genetic and environmental perturbations. Under aerobic condition, k-OptForce identifies interventions that match existing experimental strategies while pointing at a number of unexplored flux re-directions such as routing glyoxylate flux through the glycerate metabolism to improve succinate yield. Many of the identified interventions rely on the kinetic descriptions that would not be discoverable by a purely stoichiometric description. In contrast, under fermentative (anaerobic) condition, k-OptForce fails to identify key interventions including up-regulation of anaplerotic reactions and elimination of competitive fermentative products. This is due to the fact that the pathways activated under anaerobic condition were not properly parameterized as only aerobic flux data were used in the model construction. This study shed light on the importance of condition-specific model parameterization and provides insight on how to augment kinetic models so as to correctly respond to multiple environmental perturbations.

  13. Amycolatopsis tucumanensis sp. nov., a copper-resistant actinobacterium isolated from polluted sediments.

    PubMed

    Albarracín, Virginia Helena; Alonso-Vega, Pablo; Trujillo, Martha E; Amoroso, María Julia; Abate, Carlos Mauricio

    2010-02-01

    A novel actinomycete strain, ABO(T), isolated from copper-polluted sediments showed remarkable copper resistance as well as high bioaccumulation abilities. Classical taxonomic methods, including chemotaxonomy and molecular techniques, were used to characterize the isolate. Strain ABO(T) developed a honey-yellow substrate mycelium on all ISP media tested. Abundant, white, aerial mycelium was only formed on ISP 2, 5 and 7 and MM agar. Both types of hyphae fragmented into squarish rod-shaped elements. The aerial mycelium displayed spore-like structures with smooth surfaces in long, straight to flexuous chains. The organism has a type-IV cell wall lacking mycolic acids and type-A whole-cell sugar pattern (meso-diaminopimelic acid, arabinose and galactose) in addition to a phospholipid type-II profile. 16S rRNA gene sequence studies indicated that this organism is a member of the family Pseudonocardiaceae and that it forms a monophyletic clade with Amycolatopsis eurytherma NT202(T). The DNA-DNA relatedness of strain ABO(T) to A. eurytherma DSM 44348(T) was 39.5 %. It is evident from these genotypic and phenotypic data that strain ABO(T) represents a novel species in the genus Amycolatopsis, for which the name proposed is Amycolatopsis tucumanensis sp. nov. The type strain is ABO(T) (=DSM 45259(T) =LMG 24814(T)).

  14. Citricoccus zhacaiensis B-4 (MTCC 12119) a novel osmotolerant plant growth promoting actinobacterium enhances onion (Allium cepa L.) seed germination under osmotic stress conditions.

    PubMed

    Selvakumar, Govindan; Bhatt, Ravindra M; Upreti, Kaushal K; Bindu, Gurupadam Hema; Shweta, Kademani

    2015-05-01

    The water potential of rhizospheric soil is a key parameter that determines the availability of water, oxygen, and nutrients to plants and microbes. Recent global warming trends and erratic precipitation patterns have resulted in the emergence of drought as a major constraint of agricultural productivity. Though several strategies are being evaluated to address this issue, a novel approach is the utilization of microbes for alleviation of drought stress effects in crops. Citricoccus zhacaiensis B-4 is an osmotolerant actinobacterium isolated from banana rhizosphere on mannitol supplemented medium (-2.92 MPa osmotic potential). This isolate expressed plant growth promotion traits viz, IAA, GA3 production, phosphate, zinc solubilization, ACC deaminase activity and ammonia production under PEG induced osmotic stress and non-stress conditions. Under in vitro osmotic conditions, biopriming with the actinobacterium improved the percent germination, seedling vigour and germination rate of onion seeds (cv. Arka Kalyan) at osmotic potentials up to -0.8 MPa. Considering its novelty, osmotolerance and plant growth promoting traits, biopriming with C. zhacaiensis is suggested as a viable option for the promotion of onion seed germination under drought stressed environments.

  15. Streptomyces humi sp. nov., an actinobacterium isolated from soil of a mangrove forest.

    PubMed

    Zainal, Nurullhudda; Ser, Hooi-Leng; Yin, Wai-Fong; Tee, Kok-Keng; Lee, Learn-Han; Chan, Kok-Gan

    2016-03-01

    A novel Streptomyces strain, MUSC 119(T), was isolated from a soil collected from a mangrove forest. Cells of MUSC 119(T) stained Gram-positive and formed light brownish grey aerial mycelium and grayish yellowish brown substrate mycelium on ISP 2 medium. A polyphasic approach was used to determine the taxonomic status of strain MUSC 119(T), which shows a range of phylogenetic and chemotaxonomic properties consistent with those of the genus Streptomyces. The cell wall peptidoglycan consisted of LL-diaminopimelic acid. The predominant menaquinones were identified as MK-9(H8), MK-9(H6) and MK-9(H4). The polar lipid profile consisted of phosphatidylinositol, phosphatidylethanolamine, glycolipids, diphosphatidylglycerol and four phospholipids. The predominant cellular fatty acids were anteiso-C15:0, iso-C16:0, and anteiso-C17:0. The cell wall sugars were glucose, mannose, ribose and rhamnose. The phylogenetic analysis based on 16S rRNA gene sequence similarity showed that strain MUSC119(T) to be closely related to Streptomyces rhizophilus JR-41(T) (99.0 % sequence similarity), S. panaciradicis 1MR-8(T) (98.9 %), S. gramineus JR-43(T) (98.8 %) and S. graminisoli JR-19(T) (98.7 %). These results suggest that MUSC 119(T) should be placed within the genus Streptomyces. DNA-DNA relatedness values between MUSC 119(T) to closely related strains ranged from 14.5 ± 1.3 to 27.5 ± 0.7 %. The G+C content was determined to be 72.6 mol %. The polyphasic study of MUSC 119(T) showed that this strain represents a novel species, for which the name Streptomyces humi sp. nov. is proposed. The type strain of S. humi is MUSC 119(T) (=DSM 42174(T) = MCCC 1K00505(T)).

  16. High-quality draft genome sequence of Kocuria marina SO9-6, an actinobacterium isolated from a copper mine

    PubMed Central

    Castro, Daniel B.A.; Pereira, Letícia Bianca; Silva, Marcus Vinícius M. e; Silva, Bárbara P. da; Palermo, Bruna Rafaella Z.; Carlos, Camila; Belgini, Daiane R.B.; Limache, Elmer Erasmo G.; Lacerda, Gileno V. Jr; Nery, Mariana B.P.; Gomes, Milene B.; Souza, Salatiel S. de; Silva, Thiago M. da; Rodrigues, Viviane D.; Paulino, Luciana C.; Vicentini, Renato; Ferraz, Lúcio F.C.; Ottoboni, Laura M.M.

    2015-01-01

    An actinobacterial strain, designated SO9-6, was isolated from a copper iron sulfide mineral. The organism is Gram-positive, facultatively anaerobic, and coccoid. Chemotaxonomic and phylogenetic properties were consistent with its classification in the genus Kocuria. Here, we report the first draft genome sequence of Kocuria marina SO9-6 under accession JROM00000000 (http://www.ncbi.nlm.nih.gov/nuccore/725823918), which provides insights for heavy metal bioremediation and production of compounds of biotechnological interest. PMID:26484219

  17. High-quality draft genome sequence of Kocuria marina SO9-6, an actinobacterium isolated from a copper mine.

    PubMed

    Castro, Daniel B A; Pereira, Letícia Bianca; Silva, Marcus Vinícius M E; Silva, Bárbara P da; Palermo, Bruna Rafaella Z; Carlos, Camila; Belgini, Daiane R B; Limache, Elmer Erasmo G; Lacerda, Gileno V Jr; Nery, Mariana B P; Gomes, Milene B; Souza, Salatiel S de; Silva, Thiago M da; Rodrigues, Viviane D; Paulino, Luciana C; Vicentini, Renato; Ferraz, Lúcio F C; Ottoboni, Laura M M

    2015-09-01

    An actinobacterial strain, designated SO9-6, was isolated from a copper iron sulfide mineral. The organism is Gram-positive, facultatively anaerobic, and coccoid. Chemotaxonomic and phylogenetic properties were consistent with its classification in the genus Kocuria. Here, we report the first draft genome sequence of Kocuria marina SO9-6 under accession JROM00000000 (http://www.ncbi.nlm.nih.gov/nuccore/725823918), which provides insights for heavy metal bioremediation and production of compounds of biotechnological interest.

  18. Streptomyces antioxidans sp. nov., a Novel Mangrove Soil Actinobacterium with Antioxidative and Neuroprotective Potentials

    PubMed Central

    Ser, Hooi-Leng; Tan, Loh Teng-Hern; Palanisamy, Uma D.; Abd Malek, Sri N.; Yin, Wai-Fong; Chan, Kok-Gan; Goh, Bey-Hing; Lee, Learn-Han

    2016-01-01

    A novel strain, Streptomyces antioxidans MUSC 164T was recovered from mangrove forest soil located at Tanjung Lumpur, Malaysia. The Gram-positive bacterium forms yellowish-white aerial and brilliant greenish yellow substrate mycelium on ISP 2 agar. A polyphasic approach was used to determine the taxonomy status of strain MUSC 164T. The strain showed a spectrum of phylogenetic and chemotaxonomic properties consistent with those of the members of the genus Streptomyces. The cell wall peptidoglycan was determined to contain LL-diaminopimelic acid. The predominant menaquinones were identified as MK-9(H6) and MK-9(H8), while the identified polar lipids consisted of aminolipid, diphosphatidylglycerol, glycolipid, hydroxyphosphatidylethanolamine, phospholipid, phosphatidylinositol, phosphatidylethanolamine, phosphatidylglycerol and lipid. The cell wall sugars consist of galactose, glucose and ribose. The predominant cellular fatty acids (>10.0%) were identified as iso-C15:0 (34.8%) and anteiso-C15:0(14.0%). Phylogenetic analysis identified that closely related strains for MUSC 164T as Streptomyces javensis NBRC 100777T (99.6% sequence similarity), Streptomyces yogyakartensis NBRC 100779T (99.6%) and Streptomyces violaceusniger NBRC 13459T (99.6%). The DNA–DNA relatedness values between MUSC 164T and closely related type strains ranged from 23.8 ± 0.3% to 53.1 ± 4.3%. BOX-PCR fingerprints comparison showed that MUSC 164T exhibits a unique DNA profile, with DNA G + C content determined to be 71.6 mol%. Based on the polyphasic study of MUSC 164T, it is concluded that this strain represents a novel species, for which the name Streptomyces antioxidans sp. nov. is proposed. The type strain is MUSC 164T (=DSM 101523T = MCCC 1K01590T). The extract of MUSC 164T showed potent antioxidative and neuroprotective activities against hydrogen peroxide. The chemical analysis of the extract revealed that the strain produces pyrazines and phenolic-related compounds that could explain

  19. Regulation of a nickel-cobalt efflux system and nickel homeostasis in a soil actinobacterium Streptomyces coelicolor.

    PubMed

    Kim, Hae Mi; Ahn, Bo-Eun; Lee, Ju-Hyung; Roe, Jung-Hye

    2015-04-01

    In Streptomyces coelicolor, a soil actinobacterium capable of morphological differentiation and complex secondary metabolism, nickel deficiency is sensed by Nur, a Ni-specific Fur family regulator that controls nickel uptake systems (NikABCDE and NikMNOQ) and both Fe-containing and Ni-containing superoxide dismutases (SodF and SodN). On the other hand, the nickel efflux system and its regulator have not been elucidated. In this study, we demonstrate that an ArsR/SmtB family metalloregulator NmtR, a close homologue of NmtR from Mycobacterium tuberculosis, controls a putative efflux pump of P1-type ATPase (NmtA) in S. coelicolor. NmtR binds to the nmtA promoter region to repress its transcription, and is dissociated in the presence of Ni(ii) and Co(ii). Disruption of the nmtA gene makes cells more sensitive to nickel and cobalt, consistent with its predicted role in encoding a Ni-Co-efflux pump. Growth of S. coelicolor in complex YEME medium is only marginally inhibited by up to 0.5 mM Ni(ii), with significant growth retardation at 1 mM. Nur-regulated sodF and nikA genes are repressed at less than 0.1 μM added NiSO4 whereas NmtR-regulated nmtA transcription is induced at 0.5 mM or more Ni(ii). This reveals the extreme sensitivity of S. coelicolor to nickel deficiency as well as tolerance to surplus nickel. How this organism and possibly other actinomycetes have evolved to develop such a highly Ni-tolerant physiology and how the highly sensitive regulator Nur and the obtuse regulator NmtR achieve their characteristic Ni-sensitivity are interesting questions to solve in the future.

  20. Pentachlorophenol degradation by Janibacter sp., a new actinobacterium isolated from saline sediment of arid land.

    PubMed

    Khessairi, Amel; Fhoula, Imene; Jaouani, Atef; Turki, Yousra; Cherif, Ameur; Boudabous, Abdellatif; Hassen, Abdennaceur; Ouzari, Hadda

    2014-01-01

    Many pentachlorophenol- (PCP-) contaminated environments are characterized by low or elevated temperatures, acidic or alkaline pH, and high salt concentrations. PCP-degrading microorganisms, adapted to grow and prosper in these environments, play an important role in the biological treatment of polluted extreme habitats. A PCP-degrading bacterium was isolated and characterized from arid and saline soil in southern Tunisia and was enriched in mineral salts medium supplemented with PCP as source of carbon and energy. Based on 16S rRNA coding gene sequence analysis, the strain FAS23 was identified as Janibacter sp. As revealed by high performance liquid chromatography (HPLC) analysis, FAS23 strain was found to be efficient for PCP removal in the presence of 1% of glucose. The conditions of growth and PCP removal by FAS23 strain were found to be optimal in neutral pH and at a temperature of 30 °C. Moreover, this strain was found to be halotolerant at a range of 1-10% of NaCl and able to degrade PCP at a concentration up to 300 mg/L, while the addition of nonionic surfactant (Tween 80) enhanced the PCP removal capacity.

  1. Production and optimization of L-asparaginase by an actinobacterium isolated from Nizampatnam mangrove ecosystem.

    PubMed

    Kiranmayi, M Usha; Poda, Sudhakar; Vijayalakshmi, M

    2014-09-01

    The aim of the present study was to isolate and screen actinomycetes from the mangrove sediments of Nizampatnam that are potent to produce L-asparaginase, an enzyme that catalyses the hydrolysis of asparagine. A total of 31 actinomycetes strains were isolated, of which 6 strains were positive for L-asparaginase. Several physico-chemical parameters were optimized for maximizing L-asparaginase production by the potent strain identified as Pseudonocardia endophytica VUK-10. Production of L-asparaginase by the strain was high in modified Asparagine glucose salts broth (FM-4)(3.96 IU/ml) as compared to other tested media. Maltose(6.99 IU ml(-1)) and L-asparagine (7.42 IU ml(-1)) were found to be the most suitable carbon and nitrogen sources for optimum enzyme production. Maximum production of L-asparaginase was found in the culture medium with pH 8 and temperature 30 degrees C incubated for four days. This is the first report on the production of L-asparaginase by Pseudonocardia endophytica VUK-10 from Nizampatnam mangrove sediments.

  2. Pentachlorophenol Degradation by Janibacter sp., a New Actinobacterium Isolated from Saline Sediment of Arid Land

    PubMed Central

    Khessairi, Amel; Jaouani, Atef; Turki, Yousra; Boudabous, Abdellatif; Hassen, Abdennaceur; Ouzari, Hadda

    2014-01-01

    Many pentachlorophenol- (PCP-) contaminated environments are characterized by low or elevated temperatures, acidic or alkaline pH, and high salt concentrations. PCP-degrading microorganisms, adapted to grow and prosper in these environments, play an important role in the biological treatment of polluted extreme habitats. A PCP-degrading bacterium was isolated and characterized from arid and saline soil in southern Tunisia and was enriched in mineral salts medium supplemented with PCP as source of carbon and energy. Based on 16S rRNA coding gene sequence analysis, the strain FAS23 was identified as Janibacter sp. As revealed by high performance liquid chromatography (HPLC) analysis, FAS23 strain was found to be efficient for PCP removal in the presence of 1% of glucose. The conditions of growth and PCP removal by FAS23 strain were found to be optimal in neutral pH and at a temperature of 30°C. Moreover, this strain was found to be halotolerant at a range of 1–10% of NaCl and able to degrade PCP at a concentration up to 300 mg/L, while the addition of nonionic surfactant (Tween 80) enhanced the PCP removal capacity. PMID:25313357

  3. Draft Genome Sequence of the Deep-Subsurface Actinobacterium Tessaracoccus lapidicaptus IPBSL-7T

    PubMed Central

    Pieper, Dietmar H.; Arce-Rodríguez, Alejandro

    2016-01-01

    The type strain of Tessaracoccus lapidicaptus was isolated from the deep subsurface of the Iberian Pyrite Belt (southwest Spain). Here, we report its draft genome, consisting of 27 contigs with a ~3.1-Mb genome size. The annotation revealed 2,905 coding DNA sequences, 45 tRNA genes, and three rRNA genes. PMID:27688325

  4. Barrientosiimonas humi gen. nov., sp. nov., an actinobacterium of the family Dermacoccaceae.

    PubMed

    Lee, Learn-Han; Cheah, Yoke-Kqueen; Sidik, Shiran Mohd; Xie, Qing-Yi; Tang, Yi-Li; Lin, Hai-Peng; Mutalib, Nurul-Syakima Ab; Hong, Kui

    2013-01-01

    Three novel actinobacteria, strains 39(T), 40 and 41, were isolated from soil collected from Barrientos Island in the Antarctic. The taxonomic status of these strains was determined using a polyphasic approach. Comparison of 16S rRNA gene sequences revealed that strain 39(T) represented a novel lineage within the family Dermacoccaceae and was most closely related to members of the genera Demetria (96.9 % 16S rRNA gene sequence similarity), Branchiibius (95.7 %), Dermacoccus (94.4-95.3 %), Calidifontibacter (94.6 %), Luteipulveratus (94.3 %), Yimella (94.2 %) and Kytococcus (93.1 %). Cells were irregular cocci and short rods. The peptidoglycan type was A4α with an L-Lys-L-Ser-D-Asp interpeptide bridge. The cell-wall sugars were galactose and glucose. The major menaquinone was MK-8(H(4)). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphoglycolipid, two glycolipids and one unknown phospholipid. The acyl type of the cell-wall polysaccharide was N-acetyl. The major cellular fatty acids were anteiso-C(17 : 0) (41.97 %), anteiso-C(17 : 1)ω9c (32.16 %) and iso-C(16 : 0) (7.68 %). The DNA G+C content of strain 39(T) was 68.4 mol%. On the basis of phylogenetic and phenotypic differences from other genera of the family Dermacoccaceae, a novel genus and species, Barrientosiimonas humi gen. nov., sp. nov., is proposed; the type strain of the type species is 39(T) (=CGMCC 4.6864(T) = DSM 24617(T)).

  5. Geomechanical Modeling to Predict Wellbore Stresses and Strains for the Design of Wellbore Seal Repair Materials

    NASA Astrophysics Data System (ADS)

    Gomez, S. P.; Sobolik, S. R.; Matteo, E. N.; Dewers, T. A.; Taha, M. R.; Stormont, J. C.

    2013-12-01

    A critical aspect of designing effective wellbore seal repair materials is predicting thermo-mechanical perturbations in local stress that can compromise seal integrity. For the DOE-NETL project 'Wellbore Seal Repair Using Nanocomposite Materials,' we are especially interested in the stress-strain history of abandoned wells, as well as changes in local pressure, stress, and temperature conditions that accompany carbon dioxide injection or brine extraction. Building on existing thermo-hydro-mechanical (THM) finite element modeling of wellbore casings subject to significant tensile and shear loads, we advance a conceptual and numerical methodology to assess responses of annulus cement and casing. Bench-scale models complement bench-top experiments of an integrated seal system in an idealized scaled wellbore mock-up being used to test candidate seal repair materials. Field scale models use the stratigraphy from a pilot CO2 injection operation to estimate the necessary mechanical properties needed for a successful repair material. We report on approaches used for adapting existing wellbore models and share preliminary results of field scale models. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. SAND Number: 2013-6241A.

  6. SMET: systematic multiple enzyme targeting - a method to rationally design optimal strains for target chemical overproduction.

    PubMed

    Flowers, David; Thompson, R Adam; Birdwell, Douglas; Wang, Tsewei; Trinh, Cong T

    2013-05-01

    Identifying multiple enzyme targets for metabolic engineering is very critical for redirecting cellular metabolism to achieve desirable phenotypes, e.g., overproduction of a target chemical. The challenge is to determine which enzymes and how much of these enzymes should be manipulated by adding, deleting, under-, and/or over-expressing associated genes. In this study, we report the development of a systematic multiple enzyme targeting method (SMET), to rationally design optimal strains for target chemical overproduction. The SMET method combines both elementary mode analysis and ensemble metabolic modeling to derive SMET metrics including l-values and c-values that can identify rate-limiting reaction steps and suggest which enzymes and how much of these enzymes to manipulate to enhance product yields, titers, and productivities. We illustrated, tested, and validated the SMET method by analyzing two networks, a simple network for concept demonstration and an Escherichia coli metabolic network for aromatic amino acid overproduction. The SMET method could systematically predict simultaneous multiple enzyme targets and their optimized expression levels, consistent with experimental data from the literature, without performing an iterative sequence of single-enzyme perturbation. The SMET method was much more efficient and effective than single-enzyme perturbation in terms of computation time and finding improved solutions.

  7. Marisediminicola antarctica gen. nov., sp. nov., an actinobacterium isolated from the Antarctic.

    PubMed

    Li, Hui-Rong; Yu, Yong; Luo, Wei; Zeng, Yin-Xin

    2010-11-01

    Strain ZS314(T) was isolated from a sandy intertidal sediment sample collected from the coastal area off the Chinese Antarctic Zhongshan Station, east Antarctica (6 9° 22' 13″ S 76 ° 21' 41″ E). The cells were Gram-positive, motile, short rods. The temperature range for growth was 0-26 °C and the pH for growth ranged from 5 to 10, with optimum growth occurring within the temperature range 18-23 °C and pH range 6.0-8.0. Growth occurred in the presence of 0-6 % (w/v) NaCl, with optimum growth occurring in the presence of 2-4 % (w/v) NaCl. Strain ZS314(T) had MK-10 as the major menaquinone and anteiso-C(15 : 0), iso-C(16 : 0) and anteiso-C(17 : 0) as major fatty acids. The cell-wall peptidoglycan type was B2β with ornithine as the diagnostic diamino acid. The major polar lipids were diphosphatidylglycerol and phosphatidylglycerol. The genomic DNA G+C content was approximately 67 mol%. Phylogenetic analysis based on 16S rRNA gene sequence similarity showed that strain ZS314(T) represents a new lineage in the family Microbacteriaceae. On the basis of the phylogenetic analyses and phenotypic characteristics, a new genus, namely Marisediminicola gen. nov., is proposed, harbouring the novel species Marisediminicola antarctica sp. nov. with the type strain ZS314(T) (=DSM 22350(T) =CCTCC AB 209077(T)).

  8. Application of nitroarene dioxygenases in the design of novel strains that degrade chloronitrobenzenes

    PubMed Central

    Ju, Kou‐San; Parales, Rebecca E.

    2009-01-01

    Summary Widespread application of chloronitrobenzenes as feedstocks for the production of industrial chemicals and pharmaceuticals has resulted in extensive environmental contamination with these toxic compounds, where they pose significant risks to the health of humans and wildlife. While biotreatment in general is an attractive solution for remediation, its effectiveness is limited with chloronitrobenzenes due to the small number of strains that can effectively mineralize these compounds and their ability to degrade only select isomers. To address this need, we created engineered strains with a novel degradation pathway that reduces the total number of steps required to convert chloronitrobenzenes into compounds of central metabolism. We examined the ability of 2‐nitrotoluene 2,3‐dioxygenase from Acidovorax sp. strain JS42, nitrobenzene 1,2‐dioxygenase (NBDO) from Comamonas sp. strain JS765, as well as active‐site mutants of NBDO to generate chlorocatechols from chloronitrobenzenes, and identified the most efficient enzymes. Introduction of the wild‐type NBDO and the F293Q variant into Ralstonia sp. strain JS705, a strain carrying the modified ortho pathway for chlorocatechol metabolism, resulted in bacterial strains that were able to sustainably grow on all three chloronitrobenzene isomers without addition of co‐substrates or co‐inducers. These first‐generation engineered strains demonstrate the utility of nitroarene dioxygenases in expanding the metabolic capabilities of bacteria and provide new options for improved biotreatment of chloronitrobenzene‐contaminated sites. PMID:21261918

  9. Utilization of Genomic Variations Among Xylella fastidiosa Strains for Improved Diagnostic Design

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Gram-negative, xylem-limited phytopathogenic bacterium Xylella fastidiosa causes economically important diseases in grapevine, citrus and many other plant species. Our recent whole genome comparative analysis of the four sequenced strains has identified genomic variation among these strains. The...

  10. Constraint-based strain design using continuous modifications (CosMos) of flux bounds finds new strategies for metabolic engineering.

    PubMed

    Cotten, Cameron; Reed, Jennifer L

    2013-05-01

    In recent years, a growing number of metabolic engineering strain design techniques have employed constraint-based modeling to determine metabolic and regulatory network changes which are needed to improve chemical production. These methods use systems-level analysis of metabolism to help guide experimental efforts by identifying deletions, additions, downregulations, and upregulations of metabolic genes that will increase biological production of a desired metabolic product. In this work, we propose a new strain design method with continuous modifications (CosMos) that provides strategies for deletions, downregulations, and upregulations of fluxes that will lead to the production of the desired products. The method is conceptually simple and easy to implement, and can provide additional strategies over current approaches. We found that the method was able to find strain design strategies that required fewer modifications and had larger predicted yields than strategies from previous methods in example and genome-scale networks. Using CosMos, we identified modification strategies for producing a variety of metabolic products, compared strategies derived from Escherichia coli and Saccharomyces cerevisiae metabolic models, and examined how imperfect implementation may affect experimental outcomes. This study gives a powerful and flexible technique for strain engineering and examines some of the unexpected outcomes that may arise when strategies are implemented experimentally.

  11. Humibacter antri sp. nov., an actinobacterium isolated from a natural cave, and emended description of the genus Humibacter.

    PubMed

    Lee, Soon Dong

    2013-11-01

    A novel high DNA G+C content bacterium, designated strain D7-27(T), was isolated from clay soils collected inside a natural cave in Jeju, Republic of Korea. The cells of the organism were aerobic, Gram-stain-positive, non-motile rods; its colonies were white, circular and entire in margin. Phylogenetic analyses based on 16S rRNA gene sequence comparison showed that strain D7-27(T) formed a coherent cluster with Humibacter albus of the family Microbacteriaceae (97.6 % sequence similarity). The cell-wall peptidoglycan contained ornithine and 2,4-diaminobutyric acid as the diagnostic diamino acids. The major menaquinones were MK-12 and MK-11, with MK-10 as a minor component. The polar lipids consisted mainly of phosphatidylglycerol and an unknown glycolipid. Mycolic acids were not present. The predominant fatty acids were anteiso-C17 : 0 and cyclohexyl-C17 : 0. The DNA G+C content was 66.3 mol%. DNA-DNA relatedness between strain D7-27(T) and H. albus DSM 18994(T) was 28.6 % (17.6 % in a reciprocal test). On the basis of the phenotypic, chemotaxonomic and DNA-DNA hybridization data, strain D7-27(T) ( = KCTC 33009(T) = DSM 25738(T)) is considered as the type strain of a novel species of the genus Humibacter, for which the name Humibacter antri sp. nov. is proposed. An emended description of the genus Humibacter is also provided.

  12. Aging in inbred strains of mice: study design and interim report on median lifespans and circulating IGF1 levels.

    PubMed

    Yuan, Rong; Tsaih, Shirng-Wern; Petkova, Stefka B; Marin de Evsikova, Caralina; Xing, Shuqin; Marion, Michael A; Bogue, Molly A; Mills, Kevin D; Peters, Luanne L; Bult, Carol J; Rosen, Clifford J; Sundberg, John P; Harrison, David E; Churchill, Gary A; Paigen, Beverly

    2009-06-01

    To better characterize aging in mice, the Jackson Aging Center carried out a lifespan study of 31 genetically-diverse inbred mouse strains housed in a specific pathogen-free facility. Clinical assessments were carried out every 6 months, measuring multiple age-related phenotypes including neuromuscular, kidney and heart function, body composition, bone density, hematology, hormonal levels, and immune system parameters. In a concurrent cross-sectional study of the same 31 strains at 6, 12, and 20 months, more invasive measurements were carried out followed by necropsy to assess apoptosis, DNA repair, chromosome fragility, and histopathology. In this report, which is the initial paper of a series, the study design, median lifespans, and circulating insulin-like growth factor 1 (IGF1) levels at 6, 12, and 18 months are described for the first cohort of 32 females and 32 males of each strain. Survival curves varied dramatically among strains with the median lifespans ranging from 251 to 964 days. Plasma IGF1 levels, which also varied considerably at each time point, showed an inverse correlation with a median lifespan at 6 months (R = -0.33, P = 0.01). This correlation became stronger if the short-lived strains with a median lifespan < 600 days were removed from the analysis (R = -0.53, P < 0.01). These results support the hypothesis that the IGF1 pathway plays a key role in regulating longevity in mice and indicates that common genetic mechanisms may exist for regulating IGF1 levels and lifespan.

  13. Aging in inbred strains of mice: study design and interim report on median lifespans and circulating IGF1 levels

    PubMed Central

    Yuan, Rong; Tsaih, Shirng-Wern; Petkova, Stefka B.; de Evsikova, Caralina Marin; Xing, Shuqin; Marion, Michael A.; Bogue, Molly A.; Mills, Kevin D.; Peters, Luanne L.; Bult, Carol J.; Rosen, Clifford J.; Sundberg, John P.; Harrison, David E.; Churchill, Gary A.; Paigen, Beverly

    2009-01-01

    Summary To better characterize aging in mice, the Jackson Aging Center carried out a lifespan study of 31 genetically-diverse inbred mouse strains housed in a specific pathogen-free facility. We carried out clinical assessments every 6 months, measuring multiple age-related phenotypes including neuromuscular, kidney and heart function, body composition, bone density, hematology, hormonal levels, and immune system parameters. In a concurrent cross-sectional study of the same 31 strains at 6, 12, and 20 months, we carried out more invasive measurements followed by necropsy to assess apoptosis, DNA repair, chromosome fragility, and histopathology. In this report, which is the initial paper of a series, we describe the study design, median lifespans, and circulating IGF1 levels at 6, 12 and 18 months for the first cohort of 32 females and 32 males of each strain. Survival curves varied dramatically among strains with median lifespans ranging from 251 to 964 days. Plasma IGF1 levels, which also varied considerably at each time point, showed an inverse correlation with median lifespan at 6 months (R=−0.33, P=0.01). This correlation became stronger if the short-lived strains with a median lifespan<600 days were removed from the analysis (R=−0.53, P<0.01). These results support the hypothesis that the IGF1 pathway plays a key role in regulating longevity in mice and indicates that common genetic mechanisms may exist for regulating IGF1 levels and lifespan. PMID:19627267

  14. Adsorption by design: Tuning atom-graphene van der Waals interactions via mechanical strain

    NASA Astrophysics Data System (ADS)

    Nichols, Nathan S.; Del Maestro, Adrian; Wexler, Carlos; Kotov, Valeri N.

    2016-05-01

    We aim to understand how the van der Waals force between neutral adatoms and a graphene layer is modified by uniaxial strain and electron correlation effects. A detailed analysis is presented for three atoms (He, H, and Na) and graphene strain ranging from weak to moderately strong. We show that the van der Waals potential can be significantly enhanced by strain, and present applications of our results to the problem of elastic scattering of atoms from graphene. In particular, we find that quantum reflection can be significantly suppressed by strain, meaning that dissipative inelastic effects near the surface become of increased importance. Furthermore, we introduce a method to independently estimate the Lennard-Jones parameters used in an effective model of He interacting with graphene, and determine how they depend on strain. At short distances, we find that strain tends to reduce the interaction strength by pushing the location of the adsorption potential minima to higher distances above the deformed graphene sheet. This opens up the exciting possibility of mechanically engineering an adsorption potential, with implications for the formation and observation of anisotropic low-dimensional superfluid phases.

  15. Strain measurement of objects subjected to aerodynamic heating using digital image correlation: Experimental design and preliminary results

    NASA Astrophysics Data System (ADS)

    Pan, Bing; Jiang, Tianyun; Wu, Dafang

    2014-11-01

    In thermomechanical testing of hypersonic materials and structures, direct observation and quantitative strain measurement of the front surface of a test specimen directly exposed to severe aerodynamic heating has been considered as a very challenging task. In this work, a novel quartz infrared heating device with an observation window is designed to reproduce the transient thermal environment experienced by hypersonic vehicles. The specially designed experimental system allows the capture of test article's surface images at various temperatures using an optical system outfitted with a bandpass filter. The captured images are post-processed by digital image correlation to extract full-field thermal deformation. To verify the viability and accuracy of the established system, thermal strains of a chromiumnickel austenite stainless steel sample heated from room temperature up to 600 °C were determined. The preliminary results indicate that the air disturbance between the camera and the specimen due to heat haze induces apparent distortions in the recorded images and large errors in the measured strains, but the average values of the measured strains are accurate enough. Limitations and further improvements of the proposed technique are discussed.

  16. Strain measurement of objects subjected to aerodynamic heating using digital image correlation: experimental design and preliminary results.

    PubMed

    Pan, Bing; Jiang, Tianyun; Wu, Dafang

    2014-11-01

    In thermomechanical testing of hypersonic materials and structures, direct observation and quantitative strain measurement of the front surface of a test specimen directly exposed to severe aerodynamic heating has been considered as a very challenging task. In this work, a novel quartz infrared heating device with an observation window is designed to reproduce the transient thermal environment experienced by hypersonic vehicles. The specially designed experimental system allows the capture of test article's surface images at various temperatures using an optical system outfitted with a bandpass filter. The captured images are post-processed by digital image correlation to extract full-field thermal deformation. To verify the viability and accuracy of the established system, thermal strains of a chromiumnickel austenite stainless steel sample heated from room temperature up to 600 °C were determined. The preliminary results indicate that the air disturbance between the camera and the specimen due to heat haze induces apparent distortions in the recorded images and large errors in the measured strains, but the average values of the measured strains are accurate enough. Limitations and further improvements of the proposed technique are discussed.

  17. Design and validation of high-precision wireless strain sensors for structural health monitoring of steel structures

    NASA Astrophysics Data System (ADS)

    Jo, Hongki; Park, JongWoong; Spencer, B. F., Jr.; Jung, Hyung-Jo

    2012-04-01

    Due to their cost-effectiveness and ease of installation, smart wireless sensors have received considerable recent attention for structural health monitoring of civil infrastructure. Though various wireless smart sensor networks (WSSN) have been successfully implemented for full-scale structural health monitoring (SHM) applications, monitoring of low-level ambient strain still remains a challenging problem for wireless smart sensors (WSS) due to A/D converter resolution, inherent circuit noise, and the need for automatic operation. In this paper, the design and validation of high-precision strain sensor board for Imote2 WSS platform and its application to SHM of a cable-stayed bridge are presented. By accurate and automated balancing the Wheatstone bridge, signal amplification of up to 2507-times can be obtained. Temperature compensation and shunt calibration are implemented. In addition to traditional foil-type strain gages, the sensor board has been designed to accommodate a friction-type magnet strain sensor, facilitating fast and easy deployment. The sensor board has been calibrated using lab-scale tests, and then deployed on a full-scale cable-stayed bridge to verify its performance.

  18. Design and optimisation of suspended strained germanium membranes for near-infrared lasing (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Burt, Daniel; Aldeek, Waseem; Aldaghri, Osamah A.; Ikonic, Zoran; Querin, Oswaldo M.; Kelsall, Robert W.

    2016-05-01

    The development of a semiconductor laser compatible with silicon substrates and high-volume silicon integrated circuit manufacturing is a key requirement for monolithic silicon photonic transceivers. Tensile strained germanium is a promising material system which meets these criteria, and both optically pumped and electrically injected lasing have been reported[1,2]. It is well established that growth of thick (~1 micron) layers of germanium on silicon substrates by two-stage chemical vapour deposition followed by thermal annealing results in nearly-relaxed germanium with a residual biaxial tensile strain of typically 0.15-0.25% [3]. Several researchers have investigated methods of amplifying this built-in strain in order to increase the attainable optical gain. Increased uniaxial strain levels have been demonstrated in suspended linear bridge structures created by wet chemical underetching. However, uniaxial strain is less effective than biaxial strain in converting germanium from an indirect to a direct gap semiconductor and hence generating substantial optical gain. In this work, we have computationally investigated and optimised two-dimensional patterning and under-etching of germanium membranes in order to achieve biaxial strain amplification. Strain simulations were carried out using finite element methods and the shape of the suspended germanium structures was optimised to achieve the highest tensile strain whilst remaining below the empirically determined yield strength of the thin membranes. The net optical gain distribution across the membrane was calculated using 8 band k.p bandstructure to determine the full interband gain, the inter-valence-band absorption and the intervalley and intravalley phonon- and impurity-assisted free carrier absorption. Band-gap narrowing effects were included using empirical data. Biaxial strain values of ~1% can be achieved in the lasing region of the structure, which, although below the level required to convert germanium

  19. General Strain Theory as a Basis for the Design of School Interventions

    ERIC Educational Resources Information Center

    Moon, Byongook; Morash, Merry

    2013-01-01

    The research described in this article applies general strain theory to identify possible points of intervention for reducing delinquency of students in two middle schools. Data were collected from 296 youths, and separate negative binomial regression analyses were used to identify predictors of violent, property, and status delinquency. Emotional…

  20. Functional elucidation of hypothetical proteins for their indispensable roles towards drug designing targets from Helicobacter pylori strain HPAG1.

    PubMed

    Singh, Gagandeep; Singh, Vikram

    2017-03-03

    Helicobacter pylori is a flagellated and slow growing gram-negative bacterium that persistently infects about half of the entire world population. In present study, we examined the proteome of Helicobacter pylori strain HPAG1 for identification of key uncharacterized proteins towards their novel regulatory functions. The complete proteome of this strain consists of 1539 proteins, out of which 520 proteins are annotated as hypothetical. Based on the functional motifs in their primary sequences, we were able to classify 254 of these hypothetical proteins into 6 functional categories. Further, KEGG database was used to find the roles of these hypothetical proteins in several pathways and structural prediction was done by homology modelling methods. 33 of these hypothetical proteins were found to have strong association in various pathways including signalling and defence mechanisms. We noted that 27 of these proteins are specific to H. pylori and can be selected for drug designing targets, based on their virulence and regulatory role. We were able to successfully model the 3D structures of 3 of these proteins: YP_626977.1, YP_626786.1 and YP_628146.1. The stability of these proteins was also validated using molecular dynamics simulations and their possible role in the regulation of different pathways was explained. These novel annotations may contribute to the understanding of disease mechanism at molecular level and provide novel potential targets for designing new drugs against H. pylori strain HPAG1.

  1. Design and implementation of an x-ray strain measurement capability using a rotating anode machine

    SciTech Connect

    Roberts, J.A.; Rangaswamy, P.; Lujan, M. Jr.; Bourke, M.A.M.

    1998-12-31

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Residual stresses close to the surface can improve the reliability and lifetime of parts for technological applications. X-ray diffraction plays a significant role in gaining an exact knowledge of the stresses at the surface and their depth distribution. An x-ray capability at Los Alamos is key to developing and maintaining industrial collaborations in strain effects. To achieve this goal, the authors implemented a residual strain measuring station on the rotating anode x-ray instrument at the Lujan Center. This capability has been used to investigate residual strains in heat treated automotive components, machining effects on titanium alloys, resistance welded steel joints, titanium matrix fiber reinforced composites, ceramic matrix composites, thin films, and ceramic coatings. The overall objective is to combine both x-ray and neutron diffraction measurements with numerical models (e.g., finite element calculations).

  2. Design guidelines for GaSb/InAs TFET exploiting strain and device size

    NASA Astrophysics Data System (ADS)

    Visciarelli, Michele; Gnani, Elena; Gnudi, Antonio; Reggiani, Susanna; Baccarani, Giorgio

    2017-03-01

    A simulation study exploring the possibility of performance improvements for GaSb/InAs nanowire TFETs under appropriate stress conditions is carried out. It is demonstrated that biaxial tensile strain induces a remarkable enhancement of the on-state current thanks to bandgap reduction; however, a degradation of the ambipolar behavior is observed as well. Some stress intensity values and device geometry configurations are investigated. The best simulated device can achieve an on/off current ratio of about 3 ×107 with ION ≈ 0.33 mA/ μ m at VDD = 0.3 V.

  3. Strain Design of Ashbya gossypii for Single-Cell Oil Production

    PubMed Central

    Ledesma-Amaro, Rodrigo; Santos, María A.; Jiménez, Alberto

    2014-01-01

    Single-cell oil (SCO) represents a sustainable alternative for the oil industry. Accordingly, the identification of microorganisms with either higher lipidogenic ability or novel capacities for the transformation of raw materials constitutes a major challenge for the field of oil biotechnology. With this in mind, here, we were prompted to address the lipidogenic profile of the filamentous hemiascomycete Ashbya gossypii, which is currently used for the microbial production of vitamins. We found that A. gossypii mostly accumulates unsaturated fatty acids (FAs), with more than 50% of the total FA content corresponding to oleic acid. In addition, we engineered A. gossypii strains both lacking the beta-oxidation pathway and also providing ATP-citrate lyase (ACL) activity to block the degradation of FA and to increase the cytosolic acetyl-coenzyme A (CoA) content, respectively. The lipidogenic profile of the newly developed strains demonstrates that the mere elimination of the beta-oxidation pathway in A. gossypii triggers a significant increase in lipid accumulation that can reach 70% of cell dry weight. The use of A. gossypii as a novel and robust tool for the production of added-value oils is further discussed. PMID:24317081

  4. Comparative finite element analysis of the stress-strain states in three different bonded solid oxide fuel cell seal designs

    NASA Astrophysics Data System (ADS)

    Weil, K. S.; Koeppel, B. J.

    One of the critical issues in designing and fabricating a high performance planar solid oxide fuel cell (pSOFC) stack is the development of the appropriate materials and techniques for hermetically sealing the metal and ceramic components. A second critical issue is ensuring that the brittle ceramic cell constituents, i.e. the electrodes and electrolyte, exhibit high mechanical reliability by mitigating potential sources of thermal-mechanically induced stresses that can lead to fracture during operation and/or shutdown. A foil-based sealing approach is currently being developed that appears to offer good hermeticity and mechanical integrity, while minimizing the generation of high stresses in either of the joint's substrate materials. Based on the concept's viability, demonstrated in prior experimental work, numerical analyses were conducted to evaluate the behavior and benefits of the seal in a configuration prototypic of current pSOFC stack designs. This paper presents recent results from finite element (FE) simulations of a planar cell using the foil-based seal, along with companion analyses of the more conventionally employed glass-ceramic and brazed joints. The stresses and deformations of the components were evaluated at isothermal operating and shutdown temperatures. The results indicate that the foil seal is able to accommodate a significant degree of thermal mismatch strain between the metallic support structure and the ceramic cell via elastic deformations of the foil and plasticity in the foil-to-cell braze layer. Consequently the cell stresses in this type of seal are predicted to be much lower than those in the glass-ceramic and brazed designs, which is expected to lead to improved stack reliability. This ability to accommodate large thermal strain mismatches allows the design requirement of thermal expansion matching between ceramic and metal stack components to be relaxed and expands the list of candidate materials that can be considered for the

  5. Evaluating a prototype device designed to alleviate night vision goggle induced neck strain among military personnel.

    PubMed

    Dibblee, Jenna; Worthy, Portia; Farrell, Philip; Hetzler, Markus; Reid, Susan; Stevenson, Joan; Fischer, Steven

    2015-01-01

    The purpose of this study was verify the design of a novel Helmet System Support Device (HSSD) that can be used by military aircrew to help intervene on and reduce the high prevalence of neck trouble. Twelve healthy participants repeated simulated helicopter aircrew tasks on 3 separate days. On each day they wore a different helmet configuration, where measures of performance, perceived demand/preference and muscular demand were recorded. The results showed that vigilance tasks were performed over 10% faster with the HSSD configuration compared to wearing the normal helmet configuration. Participants were able to maintain static (endurance) postures for 28% longer, and use of the HSSD helped to prevent neck muscle fatigue in the most demanding task. The results of this design verification study indicate that the HSSD may be a realistic, feasible near-term solution to intervene on the high prevalence of neck trouble among rotary-wing aircrew. Practitioner Summary: This paper verifies the effectiveness of the Helmet System Support Device (HSSD) as an on-body personal protective device to help control exposures associated with aircrew neck trouble. The HSSD reduced perceived demand, reduced cumulative muscle activity in select muscles and provided improved fatigue resistance, meeting its desired design objectives.

  6. Kitasatospora sampliensis sp. nov., a novel actinobacterium isolated from soil of a sugar-cane field in India.

    PubMed

    Mayilraj, S; Krishnamurthi, S; Saha, P; Saini, H S

    2006-03-01

    Polyphasic characterization of an actinomycete strain VT-36(T) isolated from a sugar-cane field soil sample collected in Punjab State, India, revealed that the strain belongs to the genus Kitasatospora. The strain's chemotaxonomic characters and G+C content of DNA (76.5 mol%) were typical of members of the genus. Analysis of the 16S rRNA gene sequence supported the generic affiliation of the strain and showed that its closest phylogenetic relative was Kitasatospora putterlickiae F18-98T (= DSM 44665T) (98.3 % 16S rRNA gene sequence similarity). The similarities with type strains of all other Kitasatospora species were in the range 95.1-97.0 %. The results of DNA-DNA hybridization showed 54 % relatedness of the isolate and K. putterlickiae F18-98T. Based on the above data and the phenotypic differences from K. putterlickiae and other Kitasatospora species, it is proposed that the isolate should be classified as the type strain of a novel species, Kitasatospora sampliensis sp. nov., with strain VT-36T (= MTCC 6546T = DSM 44898T = JCM 13010T) as the type strain.

  7. Sunlight mediated synthesis of silver nanoparticles by a novel actinobacterium (Sinomonas mesophila MPKL 26) and its antimicrobial activity against multi drug resistant Staphylococcus aureus.

    PubMed

    Manikprabhu, Deene; Cheng, Juan; Chen, Wei; Sunkara, Anil Kumar; Mane, Sunilkumar B; Kumar, Ram; das, Mousumi; N Hozzein, Wael; Duan, Yan-Qing; Li, Wen-Jun

    2016-05-01

    Synthesis of silver nanoparticles using microorganism are many, but there are only scanty reports using actinobacteria. In the present study, the actinobacterium of the genus Sinomonas was reported to synthesis silver nanoparticles for the first time. A photo-irradiation based method was developed for the synthesis of silver nanoparticles, which includes two day old cultural supernatant of novel species Sinomonas mesophila MPKL 26 and silver nitrate solution, exposed to sunlight. The preliminary synthesis of silver nanoparticles was noted by the color change of the solution from colorless to brown; the synthesis was further confirmed using UV-visible spectroscopy which shows a peak between 400 and 450nm. Spherical shape silver nanoparticles of size range 4-50nm were synthesized, which were characterized using transmission electron microscopy. The Fourier transform infrared spectroscopy result indicates that, the metabolite produced by the novel species S. mesophila MPKL 26 was the probable reducing/capping agent involved in the synthesis of silver nanoparticles. The synthesized silver nanoparticles maintained consistent shape with respect to different time periods. The synthesized silver nanoparticles were evaluated for the antimicrobial activity against multi drug resistant Staphylococcus aureus which show good antimicrobial activity. The method developed for synthesis is easy, requires less time (20min) and produces spherical shape nanoparticles of size as small as 4nm, having good antimicrobial activity. Hence, our study enlarges the scope of actinobacteria for the rapid biosynthesis of silver nanoparticles and can be used in formulating remedies for multi drug resistant S. aureus.

  8. Pseudonocardia eucalypti sp. nov., an endophytic actinobacterium with a unique knobby spore surface, isolated from roots of a native Australian eucalyptus tree.

    PubMed

    Kaewkla, Onuma; Franco, Christopher M M

    2011-04-01

    A novel strain, designated EUM 374(T), was isolated from the root of a native Australian eucalyptus tree, Eucalyptus microcarpa, and subjected to a range of morphological, phylogenetic and chemotaxonomic analyses. The strain was Gram-reaction-positive with well-developed aerial mycelia, which fragmented into rod-shaped spores that had unique knobby protrusions on the spore surface. Substrate mycelia were not present in the media used. Strain EUM 374(T) grew as a film on the surface of static liquid culture medium but did not grow under shaking conditions. Phylogenetic evaluation based on 16S rRNA gene sequences identified the new isolate as belonging to the family Pseudonocardiaceae with sequence similarities of 96.1 and 96.3 % to Pseudonocardia acaciae GMKU095(T) and Pseudonocardia spinosispora LM 141(T), respectively, and 93-96 % sequence similarity to other members of the genus Pseudonocardia. The results of comprehensive phylogenetic analyses, including physiological and biochemical tests, differentiated strain EUM 374(T) from related members of the genus Pseudonocardia. Based on the phenotypic, phylogenetic and chemotaxonomic evidence, strain EUM 374(T) represents a novel species of the genus Pseudonocardia, for which the name Pseudonocardia eucalypti sp. nov. is proposed. The type strain is EUM 374(T) ( = DSM 45351(T)  = ACM 5285(T)).

  9. Cultivating the uncultured: growing the recalcitrant cluster-2 Frankia strains

    PubMed Central

    Gtari, Maher; Ghodhbane-Gtari, Faten; Nouioui, Imen; Ktari, Amir; Hezbri, Karima; Mimouni, Wajdi; Sbissi, Imed; Ayari, Amani; Yamanaka, Takashi; Normand, Philippe; Tisa, Louis S; Boudabous, Abdellatif

    2015-01-01

    The repeated failures reported in cultivating some microbial lineages are a major challenge in microbial ecology and probably linked, in the case of Frankia microsymbionts to atypical patterns of auxotrophy. Comparative genomics of the so far uncultured cluster-2 Candidatus Frankia datiscae Dg1, with cultivated Frankiae has revealed genome reduction, but no obvious physiological impairments. A direct physiological assay on nodule tissues from Coriaria myrtifolia infected with a closely-related strain permitted the identification of a requirement for alkaline conditions. A high pH growth medium permitted the recovery of a slow-growing actinobacterium. The strain obtained, called BMG5.1, has short hyphae, produced diazovesicles in nitrogen-free media, and fulfilled Koch’s postulates by inducing effective nodules on axenically grown Coriaria spp. and Datisca glomerata. Analysis of the draft genome confirmed its close proximity to the Candidatus Frankia datiscae Dg1 genome with the absence of 38 genes (trehalose synthase, fumarylacetoacetase, etc) in BMG5.1 and the presence of 77 other genes (CRISPR, lanthionine synthase, glutathione synthetase, catalase, Na+/H+ antiporter, etc) not found in Dg1. A multi-gene phylogeny placed the two cluster-2 strains together at the root of the Frankia radiation. PMID:26287281

  10. Draft Genome Sequence of Rhodococcus erythropolis NSX2, an Actinobacterium Isolated from a Cadmium-Contaminated Environment

    PubMed Central

    Egidi, Eleonora; Wood, Jennifer L.; Fox, Edward M.; Liu, Wuxing

    2016-01-01

    Rhodococcus erythropolis NSX2 is a rhizobacterium isolated from a heavy metal–contaminated environment. The 6.2-Mb annotated genome sequence shows that this strain harbors genes associated with heavy-metal resistance and xenobiotics degradation. PMID:27795276

  11. Lentzea chajnantorensis sp. nov., an actinobacterium from a very high altitude Cerro Chajnantor gravel soil in northern Chile.

    PubMed

    Idris, Hamidah; Nouioui, Imen; Asenjo, Juan A; Bull, Alan T; Goodfellow, Michael

    2017-03-21

    The taxonomic position of a filamentous actinobacterial strain, isolate H45(T), recovered from a high altitude Atacama Desert gravel soil, was established using a polyphasic approach. The strain, which is known to produce novel dienes, has chemotaxonomic and morphological properties typical of the genus Lentzea and formed a distinct branch in the Lentzea 16S rRNA gene tree that is closely related to the type strain of Lentzea kentuckyensis. The two strains were distinguished using a combination of phenotypic properties and by a DNA:DNA relatedness value of 37.6 ± 4.0%. On the basis of these genotypic and phenotypic data it is proposed that isolate H45(T) (=NCIMB 4966(T) = NRRL B-65282(T)) be classified in the genus Lentzea as Lentzea chajnantorensis sp. nov.

  12. Application of statistical experimental design for optimisation of bioinsecticides production by sporeless Bacillus thuringiensis strain on cheap medium.

    PubMed

    Ben Khedher, Saoussen; Jaoua, Samir; Zouari, Nabil

    2013-01-01

    In order to overproduce bioinsecticides production by a sporeless Bacillus thuringiensis strain, an optimal composition of a cheap medium was defined using a response surface methodology. In a first step, a Plackett-Burman design used to evaluate the effects of eight medium components on delta-endotoxin production showed that starch, soya bean and sodium chloride exhibited significant effects on bioinsecticides production. In a second step, these parameters were selected for further optimisation by central composite design. The obtained results revealed that the optimum culture medium for delta-endotoxin production consists of 30 g L(-1) starch, 30 g L(-1) soya bean and 9 g L(-1) sodium chloride. When compared to the basal production medium, an improvement in delta-endotoxin production up to 50% was noted. Moreover, relative toxin yield of sporeless Bacillus thuringiensis S22 was improved markedly by using optimised cheap medium (148.5 mg delta-endotoxins per g starch) when compared to the yield obtained in the basal medium (94.46 mg delta-endotoxins per g starch). Therefore, the use of optimised culture cheap medium appeared to be a good alternative for a low cost production of sporeless Bacillus thuringiensis bioinsecticides at industrial scale which is of great importance in practical point of view.

  13. A systematic optimization of design parameters in strained silicon waveguides to further enhance the linear electro-optic effect

    NASA Astrophysics Data System (ADS)

    Olivares, Irene; Angelova, Todora I.; Pinilla-Cienfuegos, Elena; Sanchis, Pablo

    2016-05-01

    The electro-optic Pockels effect may be generated in silicon photonics structures by breaking the crystal symmetry by means of a highly stressing cladding layer (typically silicon nitride, SiN) deposited on top of the silicon waveguide. In this work, the influence of the waveguide parameters on the strain distribution and its overlap with the optical mode to enhance the Pockels effect has been analyzed. The optimum waveguide structure have been designed based on the definition and quantification of a figure of merit. The fabrication of highly stressing SiN layers by PECVD has also been optimized to characterize the designed structures. The residual stress has been controlled during the growth process by analyzing the influence of the main deposition parameters. Therefore, two identical samples with low and high stress conditions were fabricated and electro-optically characterized to test the induced Pockels effect and the influence of carrier effects. Electro-optical modulation was only measured in the sample with the high stressing SiN layer that could be attributed to the Pockels effect. Nevertheless, the influence of carriers were also observed thus making necessary additional experiments to decouple both effects.

  14. Stress and strain distribution in three different mini dental implant designs using in implant retained overdenture: a finite element analysis study

    PubMed Central

    AUNMEUNGTONG, W.; KHONGKHUNTHIAN, P.; RUNGSIYAKULL, P.

    2016-01-01

    SUMMARY Finite Element Analysis (FEA) has been used for prediction of stress and strain between dental implant components and bone in the implant design process. Purpose Purpose of this study was to characterize and analyze stress and strain distribution occurring in bone and implants and to compare stress and strain of three different implant designs. Materials and methods Three different mini dental implant designs were included in this study: 1. a mini dental implant with an internal implant-abutment connection (MDIi); 2. a mini dental implant with an external implant-abutment connection (MDIe); 3. a single piece mini dental implant (MDIs). All implant designs were scanned using micro-CT scans. The imaging details of the implants were used to simulate models for FEA. An artificial bone volume of 9×9 mm in size was constructed and each implant was placed separately at the center of each bone model. All bone-implant models were simulatively loaded under an axial compressive force of 100 N and a 45-degree force of 100 N loading at the top of the implants using computer software to evaluate stress and strain distribution. Results There was no difference in stress or strain between the three implant designs. The stress and strain occurring in all three mini dental implant designs were mainly localized at the cortical bone around the bone-implant interface. Oblique 45° loading caused increased deformation, magnitude and distribution of stress and strain in all implant models. Conclusions Within the limits of this study, the average stress and strain in bone and implant models with MDIi were similar to those with MDIe and MDIs. The oblique 45° load played an important role in dramatically increased average stress and strain in all bone-implant models. Clinical implications Mini dental implants with external or internal connections have similar stress distribution to single piece mini dental implants. In clinical situations, the three types of mini dental implant

  15. Optimization of Magnetosome Production and Growth by the Magnetotactic Vibrio Magnetovibrio blakemorei Strain MV-1 through a Statistics-Based Experimental Design

    PubMed Central

    Silva, Karen T.; Leão, Pedro E.; Abreu, Fernanda; López, Jimmy A.; Gutarra, Melissa L.; Farina, Marcos; Bazylinski, Dennis A.; Freire, Denise M. G.

    2013-01-01

    The growth and magnetosome production of the marine magnetotactic vibrio Magnetovibrio blakemorei strain MV-1 were optimized through a statistics-based experimental factorial design. In the optimized growth medium, maximum magnetite yields of 64.3 mg/liter in batch cultures and 26 mg/liter in a bioreactor were obtained. PMID:23396329

  16. Strain-driven and ultrasensitive resistive sensor/switch based on conductive alginate/nitrogen-doped carbon-nanotube-supported Ag hybrid aerogels with pyramid design.

    PubMed

    Zhao, Songfang; Zhang, Guoping; Gao, Yongju; Deng, Libo; Li, Jinhui; Sun, Rong; Wong, Ching-Ping

    2014-12-24

    Flexible strain-driven sensor is an essential component in the flexible electronics. Especially, high durability and sensitivity to strain are required. Here, we present an efficient and low-cost fabrication strategy to construct a highly sensitive and flexible pressure sensor based on a conductive, elastic aerogel with pyramid design. When pressure is loaded, the contact area between the interfaces of the conductive aerogel and the copper electrode as well as among the building blocks of the nitrogen-doped carbon-nanotube-supported Ag (N-CNTs/Ag) aerogel monoliths, changes in reversible and directional manners. This contact resistance mechanism enables the hybrid aerogels to act as strain-driven sensors with high sensitivity and excellent on/off swithching behavior, and the gauge factor (GF) is ∼15 under strain of 3%, which is superior to those reported for other aerogels. In addition, robust, elastomeric and conductive nanocomposites can be fabricated by injecting polydimethylsiloxane (PDMS) into alginate/N-CNTs/Ag aerogels. Importantly, the building blocks forming the aerogels retain their initial contact and percolation after undergoing large-strain deformation, PDMS infiltration, and cross-linking of PDMS, suggesting their potential applications as strain sensors.

  17. Synthetic Peptide Vaccine Development: Designing Dual Epitopes into a Single Pilin Peptide Immunogen Generates Antibody Cross-reactivity between Two Strains of Pseudomonas aeruginosa

    PubMed Central

    Hackbarth, Clifton; Hodges, Robert S.

    2010-01-01

    One of the main challenges of Pseudomonas aeruginosa (P. aeruginosa) vaccine development is the design of an antigen that elicits cross-reactive antibodies against multiple virulent strains. Using a rational design approach, we have developed a single 17-residue peptide immunogen that generates antibodies that target the receptor binding domain (RBD) of the type IV pilus of more than one strain of P. aeruginosa. Using the RBD sequence, of native strain PAO as a template, we have systematically changed up to five residues in the PAO sequence of the peptide immunogen, into that of the PAK sequence. We show by indirect and competitive ELISA, that the mutant peptide immunogens elicit the development of polyclonal sera that is cross-reactive to both native strain PAO and PAK pilin. We further show that there are at least two separate antibody populations in the polyclonal sera that possess closely-related epitopes but which are each strain specific. Moreover, part of the epitope for the PAO specific antibodies consists of several residues outside the disulfide loop of the receptor binding domain. This allows us to create two unique epitopes within the same receptor binding domain sequence. PMID:20807222

  18. Kocuria arsenatis sp. nov., a novel arsenic-resistant endophytic actinobacterium associated with Prosopis laegivata grown on high arsenic polluted mine tailing in Mexico.

    PubMed

    Román-Ponce, Brenda; Wang, Dan; Vásquez-Murrieta, María Soledad; Chen, Wen Feng; Estrada-de Los Santos, Paulina; Sui, Xin Hua; Wang, En Tao

    2015-12-08

    A Gram positive, aerobic, non-motile, coccoid, arsenic-resistant actinobacterial strain designated as CM1E1T was isolated from the lateral root tissue of Prosopis laegivata grown on a mine tailing in San Luis Potosi, Mexico. Phylogenetic analysis based on 16S rRNA genes revealed that strain CM1E1T was clustered closely with Kocuria species, showing the highest sequence similarity of 98.7 % to Kocuria rhizophila TA68T. The DNA G + C content of strain CM1E1T was 74.5 mol% (Tm). The major fatty acids were anteiso-C15:0, anteiso-C17:0 and iso-C15:0. The peptidoglycan of cell wall contained lysine and alanine. The major respiratory quinones were MK-7 (H2) and MK-8 (H2). On the basis of the phenotypic characterization, phylogenetic relation and chemotaxonomic analyses, strain CM1E1T (=CCBAU 101092T=HAMBI 3625T =LMG 8671T) represents a novel species in genus Kocuria, for which the name Kocuria arsenatis sp. nov is proposed.

  19. Genes encoding ten newly designated OXA-63 group class D β-lactamases identified in strains of the pathogenic intestinal spirochaete Brachyspira pilosicoli.

    PubMed

    La, Tom; Neo, Eugene; Phillips, Nyree D; Hampson, David J

    2015-11-01

    The anaerobic spirochaete Brachyspira pilosicoli colonizes the large intestine of birds and mammals, including human beings, and may induce colitis and diarrhoea. B. pilosicoli has a recombinant population structure, and strains show extensive genomic rearrangements and different genome sizes. The resident chromosomal gene blaOXA-63 in B. pilosicoli encodes OXA-63, a narrow-spectrum group IV class D β-lactamase. Genes encoding four OXA-63 variants have been described in B. pilosicoli, and the current study was designed to investigate the distribution and diversity of such genes and proteins in strains of B. pilosicoli. PCRs were used to amplify blaOXA-63 group genes from 118 B. pilosicoli strains from different host species and geographical origins. One primer set was targeted externally to the gene and two sets were designed to amplify internal components. A total of 16 strains (13.6%) showed no evidence of possessing blaOXA-63 group genes, 44 (37.3%) had a full gene, 27 (22.9%) apparently had a gene but it failed to amplify with external primers, and 29 (24.6%) had only one or other of the two internal components amplified. Based on translation of the nucleotide sequences, ten new variants of the β-lactamase, designated OXA-470 through OXA-479, were identified amongst the 44 strains that had the full gene amplified. The 16 strains lacking blaOXA-63 group genes had a region of 1674 bp missing around where the gene was expected to reside. Despite apparent genomic rearrangements occurring in B. pilosicoli, positive selection pressures for conservation of blaOXA-63 group genes and OXA proteins appear to have been exerted.

  20. Design of a new stretching apparatus and the effects of cyclic strain and substratum on mouse lung epithelial-12 cells.

    PubMed

    Arold, Stephen P; Wong, Joyce Y; Suki, Bela

    2007-07-01

    The pulmonary epithelium is exposed to mechanical strains during normal breathing or mechanical ventilation. While important for the regulation of cellular processes, excessive strains damage epithelial cells. To investigate the effects of strain on the epithelium, we developed a stretching device to apply equi-biaxial strains to cells cultured on elastic membranes. Following device validation, we exposed a murine epithelial cell line (MLE-12) to 30 min of cyclic stretch with 0, 25, 50, 75 and 100% change in surface area on pronectin or type I collagen coated membranes. Following stretch, we assessed cell viability using fluorescent immunocytochemisty and surfactant secretion using [(3)H] labeled phosphatidylcholine (PC). Cell injury increased with increasing strain with cells on pronectin showing more injury than on type I collagen. Stretching had no effect on surfactant secretion on either substratum suggesting MLE-12 cells are a poor model for stretch-induced surfactant secretion. The cells grown on pronectin, however, demonstrated a 3-fold increase in surfactant secretion compared to those grown on type I collagen at all strains. This suggests that, while this cell line does not demonstrate stretch-induced surfactant secretion, the underlying extracellular matrix plays a crucial factor in both cell death and signal transduction in response to strain.

  1. Design of a pulse-type strain gauge balance for a long-test-duration hypersonic shock tunnel

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Liu, Y.; Jiang, Z.

    2016-11-01

    When the measurement of aerodynamic forces is conducted in a hypersonic shock tunnel, the inertial forces lead to low-frequency vibrations of the model, and its motion cannot be addressed through digital filtering because a sufficient number of cycles cannot be obtained during a tunnel run. This finding implies restrictions on the model size and mass as the natural frequencies are inversely proportional to the length scale of the model. Therefore, the force measurement still has many problems, particularly for large and heavy models. Different structures of a strain gauge balance (SGB) are proposed and designed, and the measurement element is further optimized to overcome the difficulties encountered during the measurement of aerodynamic forces in a shock tunnel. The motivation for this study is to assess the structural performance of the SGB used in a long-test-duration JF12 hypersonic shock tunnel, which has more than 100 ms of test time. Force tests were conducted for a large-scale cone with a 10^° semivertex angle and a length of 0.75 m in the JF12 long-test-duration shock tunnel. The finite element method was used for the analysis of the vibrational characteristics of the Model-Balance-Sting System (MBSS) to ensure a sufficient number of cycles, particularly for the axial force signal during a shock tunnel run. The higher-stiffness SGB used in the test shows good performance, wherein the frequency of the MBSS increases because of the stiff construction of the balance. The experimental results are compared with the data obtained in another wind tunnel and exhibit good agreement at M = 7 and α =5°.

  2. In vivo strains in the femur of the Virginia opossum (Didelphis virginiana) during terrestrial locomotion: testing hypotheses of evolutionary shifts in mammalian bone loading and design.

    PubMed

    Butcher, Michael T; White, Bartholomew J; Hudzik, Nathan B; Gosnell, W Casey; Parrish, John H A; Blob, Richard W

    2011-08-01

    Terrestrial locomotion can impose substantial loads on vertebrate limbs. Previous studies have shown that limb bones from cursorial species of eutherian mammals experience high bending loads with minimal torsion, whereas the limb bones of non-avian reptiles (and amphibians) exhibit considerable torsion in addition to bending. It has been hypothesized that these differences in loading regime are related to the difference in limb posture between upright mammals and sprawling reptiles, and that the loading patterns observed in non-avian reptiles may be ancestral for tetrapod vertebrates. To evaluate whether non-cursorial mammals show loading patterns more similar to those of sprawling lineages, we measured in vivo strains in the femur during terrestrial locomotion of the Virginia opossum (Didelphis virginiana), a marsupial that uses more crouched limb posture than most mammals from which bone strains have been recorded, and which belongs to a clade phylogenetically between reptiles and the eutherian mammals studied previously. The presence of substantial torsion in the femur of opossums, similar to non-avian reptiles, would suggest that this loading regime likely reflects an ancestral condition for tetrapod limb bone design. Strain recordings indicate the presence of both bending and appreciable torsion (shear strain: 419.1 ± 212.8 με) in the opossum femur, with planar strain analyses showing neutral axis orientations that placed the lateral aspect of the femur in tension at the time of peak strains. Such mediolateral bending was unexpected for a mammal running with near-parasagittal limb kinematics. Shear strains were similar in magnitude to peak compressive axial strains, with opossum femora experiencing similar bending loads but higher levels of torsion compared with most previously studied mammals. Analyses of peak femoral strains led to estimated safety factor ranges of 5.1-7.2 in bending and 5.5-7.3 in torsion, somewhat higher than typical mammalian values

  3. A multiscale and multiphysics model of strain development in a 1.5 T MRI magnet designed with 36 filament composite MgB2 superconducting wire

    NASA Astrophysics Data System (ADS)

    Amin, Abdullah Al; Baig, Tanvir; Deissler, Robert J.; Yao, Zhen; Tomsic, Michael; Doll, David; Akkus, Ozan; Martens, Michael

    2016-05-01

    High temperature superconductors such as MgB2 focus on conduction cooling of electromagnets that eliminates the use of liquid helium. With the recent advances in the strain sustainability of MgB2, a full body 1.5 T conduction cooled magnetic resonance imaging (MRI) magnet shows promise. In this article, a 36 filament MgB2 superconducting wire is considered for a 1.5 T full-body MRI system and is analyzed in terms of strain development. In order to facilitate analysis, this composite wire is homogenized and the orthotropic wire material properties are employed to solve for strain development using a 2D-axisymmetric finite element analysis (FEA) model of the entire set of MRI magnet. The entire multiscale multiphysics analysis is considered from the wire to the magnet bundles addressing winding, cooling and electromagnetic excitation. The FEA solution is verified with proven analytical equations and acceptable agreement is reported. The results show a maximum mechanical strain development of 0.06% that is within the failure criteria of -0.6% to 0.4% (-0.3% to 0.2% for design) for the 36 filament MgB2 wire. Therefore, the study indicates the safe operation of the conduction cooled MgB2 based MRI magnet as far as strain development is concerned.

  4. Draft Genome Sequence of Brucella abortus S99: Designated Antigenic Smooth Reference Strain Used in Diagnostic Tests in India

    PubMed Central

    Shome, Rajeswari; Krithiga, Natesan; Padmashree, B. S.; Sankarasubramanian, Jagadesan; Vishnu, Udayakumar S.; Sridhar, Jayavel; Gunasekaran, Paramasamy; Rahman, Habibur

    2014-01-01

    Brucella abortus strain S99 is widely used for the preparation of colored, plain, recombinant and smooth lipopolysaccharide antigens for the preparation of Brucella diagnostic kits. The genome of this strain was sequenced and the length of the genome was 3,253,175 bp, with 57.2% G+C content. A total of 3,365 protein coding genes and 53 RNA genes were predicted. PMID:25146137

  5. Draft Genome Sequence of Brucella abortus S99: Designated Antigenic Smooth Reference Strain Used in Diagnostic Tests in India.

    PubMed

    Shome, Rajeswari; Krithiga, Natesan; Padmashree, B S; Sankarasubramanian, Jagadesan; Vishnu, Udayakumar S; Sridhar, Jayavel; Gunasekaran, Paramasamy; Rajendhran, Jeyaprakash; Rahman, Habibur

    2014-08-21

    Brucella abortus strain S99 is widely used for the preparation of colored, plain, recombinant and smooth lipopolysaccharide antigens for the preparation of Brucella diagnostic kits. The genome of this strain was sequenced and the length of the genome was 3,253,175 bp, with 57.2% G+C content. A total of 3,365 protein coding genes and 53 RNA genes were predicted.

  6. Fly's proprioception-inspired micromachined strain-sensing structure: idea, design, modeling and simulation, and comparison with experimental results

    NASA Astrophysics Data System (ADS)

    Wicaksono, D. H. B.; Zhang, L.-J.; Pandraud, G.; French, P. J.; Vincent, J. F. V.

    2006-04-01

    A new strain-sensing structure inspired from insect's (especially the Fly) propricoception sensor is devised. The campaniform sensillum is a strain-sensing microstructure with very high sensitivity despite its small dimension (diameter ~10 µm in a relatively stiff material of insect's exocuticle (E = ~109 Pa). Previous work shows that the high sensitivity of this structure towards strain is due to its membrane-in-recess- and strainconcentrating- hole- features. Based on this inspiration, we built similar structure using silicon micromachining technology. Then a simple characterisation setup was devised. Here, we present briefly, finite-element modeling and simulation based on this actual sample preparation for the characterisation. As comparison and also to understand mechanical features responsible for the strain-sensitivity, we performed the modeling on different mechanical structures: bulk chunk, blind-hole, thorugh-hole, surface membrane, and membrane-in-recess. The actual experimental characterisation was performed previously using optical technique to membranein- recess micromachined Si structure. The FEM simulation results confirm that the bending stress and strain are concentrated in the hole-vicinity. The membrane inside the hole acts as displacement transducer. The FEM is in conformity with previous analytical results, as well as the optical characterisation result. The end goal is to build a new type MEMS strain sensor.

  7. Design and proposal of dual line-of-defense perimeter watchdog incorporating optimally designed FBG based accelerometers and strain sensors using single optical fiber

    NASA Astrophysics Data System (ADS)

    Khan, Mohd. Mansoor; Sonkar, Ramesh Kumar

    2015-06-01

    Paper presents Opto-Mechanical intrusion sensor fence with FBGs attached to mechanical accelerometers and strain sensors, optimized on SolidWorks 2013 for desired frequency to 35 Hz, picking up accelerations/ strains and its deployment for perimeter security. The accelerometer structure consists of inertial mass supported by an L-shaped modified cantilever beam having non-uniform cross section area connected to base by a thin neck element which acts as strain concentrated centre hence an optimum zone for FBG sensors placement. Bragg wavelength shifts were obtained on Optigrating software for the obtained strain values on mechanical assembly of fence. CFD wind analysis is performed on the assembly to obtain the spot for accelerometer's placement to avoid false alarms up to wind velocities of 20 m/s.

  8. Effectiveness of a newly designed construction uniform for heat strain attenuation in a hot and humid environment.

    PubMed

    Yi, Wen; Chan, Albert P C; Wong, Francis K W; Wong, Del P

    2017-01-01

    This study aims to evaluate the effectiveness of a newly designed construction uniform in combating heat stress. Ten male volunteers performed treadmill running in a climatic chamber maintained at 34.5 °C temperature, 75% relative humidity, 0.3 m/s air velocity, and solar radiation of 450 W/m(2) that simulates typical summer working environment of construction sites in Hong Kong. The participants were tested while wearing two kinds of construction uniforms: a commonly worn uniform A, or a newly designed uniform B. It was found during exercise that Tc (38.34 ± 0.14 vs 38.45 ± 0.11 °C, p = 0.03), Tsk (36.01 ± 0.36 vs 36.27 ± 0.34 °C, p = 0.03), HR (162.7 ± 10.1 vs 172.5 ± 9.2 bpm, p < 0.01), PSI (7.0 ± 0.4 vs 7.5 ± 0.5, p = 0.04), thermal sensation (1.7 ± 0.9 vs 2.6 ± 0.7, p = 0.02), and wetness sensation (1.9 ± 0.9 vs 2.6 ± 0.8, p < 0.01) was lower when wearing uniform B than that of uniform A. It was found during recovery that Tc (37.89 ± 0.13 vs 38.06 ± 0.13 °C, p < 0.01), Tsk (35.68 ± 0.37 vs 36.02 ± 0.41 °C, p < 0.01), HR (104.2 ± 10.1 vs 112.6 ± 10.7 bpm, p < 0.01), PSI (3.3 ± 0.7 vs 4.1 ± 1.0, p < 0.01), thermal sensation (0.1 ± 0.9 vs 1.0 ± 0.8, p = 0.02), and wetness sensation (1.1 ± 1.0 vs 2.3 ± 0.8, p = 0.02) was lower when wearing uniform B than that of uniform A. The findings of this study suggested the newly designed construction uniform could reduce thermoregulatory and cardiovascular strain, and improve thermal comfort while exercising in a hot and humid environment.

  9. Designing and exploring active N'-[(5-nitrofuran-2-yl) methylene] substituted hydrazides against three Trypanosoma cruzi strains more prevalent in Chagas disease patients.

    PubMed

    Palace-Berl, Fanny; Pasqualoto, Kerly Fernanda Mesquita; Jorge, Salomão Dória; Zingales, Bianca; Zorzi, Rodrigo Rocha; Silva, Marcelo Nunes; Ferreira, Adilson Kleber; de Azevedo, Ricardo Alexandre; Teixeira, Sarah Fernandes; Tavares, Leoberto Costa

    2015-01-01

    Chagas disease affects around 8 million people worldwide and its treatment depends on only two nitroheterocyclic drugs, benznidazole (BZD) and nifurtimox (NFX). Both drugs have limited curative power in chronic phase of disease. Nifuroxazide (NF), a nitroheterocyclic drug, was used as lead to design a set of twenty one compounds in order to improve the anti-Trypanosoma cruzi activity. Lipinski's rules were considered in order to support drug-likeness designing. The set of N'-[(5-nitrofuran-2-yl) methylene] substituted hydrazides was assayed against three T. cruzi strains, which represent the discrete typing units more prevalent in human patients: Y (TcII), Silvio X10 cl1 (TcI), and Bug 2149 cl10 (TcV). All the derivatives, except one, showed enhanced trypanocidal activity against the three strains as compared to BZD. In the Y strain 62% of the compounds were more active than NFX. The most active compound was N'-((5-nitrofuran-2-yl) methylene)biphenyl-4-carbohydrazide (C20), which showed IC50 values of 1.17 ± 0.12 μM; 3.17 ± 0.32 μM; and 1.81 ± 0.18 μM for Y, Silvio X10 cl1, and Bug 2149 cl10 strains, respectively. Cytotoxicity assays with human fibroblast cells have demonstrated high selectivity indices for several compounds. Exploratory data analysis indicated that primarily topological, steric/geometric, and electronic properties have contributed to the discrimination of the set of investigated compounds. The findings can be helpful to drive the designing, and subsequently, the synthesis of additional promising drugs against Chagas disease.

  10. Simulation-based design of a strained graphene field effect transistor incorporating the pseudo magnetic field effect

    SciTech Connect

    Souma, Satofumi Ueyama, Masayuki; Ogawa, Matsuto

    2014-05-26

    We present a numerical study on the performance of strained graphene-based field-effect transistors. A local strain less than 10% is applied over a central channel region of the graphene to induce the shift of the Dirac point in the channel region along the transverse momentum direction. The left and the right unstrained graphene regions are doped to be either n-type or p-type. By using the atomistic tight-binding model and a Green's function method, we predict that the gate voltage applied to the central strained graphene region can switch the drain current on and off with an on/off ratio of more than six orders of magnitude at room temperature. This is in spite of the absence of a bandgap in the strained channel region. Steeper subthreshold slopes below 60 mV/decade are also predicted at room temperature because of a mechanism similar to the band-to-band tunneling field-effect transistors.

  11. Nocardiopsis sp. SD5: a potent feather degrading rare actinobacterium isolated from feather waste in Tamil Nadu, India.

    PubMed

    Saha, Subhasish; Dhanasekaran, D; Shanmugapriya, S; Latha, S

    2013-07-01

    Feather waste, generated in large quantities as a byproduct of commercial poultry processing, is nearly pure keratin protein, and keratin in its native state is not degradable by common proteolytic enzymes. The aim of the study was to find a potent feather degrading actinobacteria from feather waste soil. Out of 91 actinobacterial isolates recorded from feather waste soil in Tiruchirappalli and Nammakkal District, Tamil Nadu, India, isolate SD5 was selected for characterization because it exhibited significant keratinolytic activity. On the basis of the phenotypic, biochemical characterization and 16S rRNA gene-sequencing studies, the isolate was identified as Nocardiopsis sp. SD5. Protease and keratinase activity of Nocardiopsis sp. SD5 were analyzed. The enzyme was more stable over the neutral pH and the temperature of 40 °C. The optimum temperature and pH for both proteolytic and keratinolytic activity was determined at 50 °C and pH 9, respectively. Enzyme inhibitors, detergents and chelator declined the enzyme activity with increasing concentration. Nondenaturing polyacrylamide gel electrophoresis and zymogram elucidated the presence of 30 and 60 kDa protease enzymes. These findings indicated that thermo alkaliphilic feather degrading strain Nocardiopsis sp. SD5 could be used to control the feather waste pollution and to convert keratin rich feather waste into useful feedstock for poultry industry.

  12. 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.

  13. Non-radiative recombination in Ge{sub 1−y}Sn{sub y} light emitting diodes: The role of strain relaxation in tuned heterostructure designs

    SciTech Connect

    Gallagher, J. D.; Xu, C.; Smith, D. J.; Menéndez, J.; Senaratne, C. L.; Sims, P.; Kouvetakis, J.; Aoki, T.

    2015-06-28

    This paper describes the properties of Ge{sub 1−y}Sn{sub y} light emitting diodes with a broad range of Sn concentrations (y = 0.0–0.11). The devices are grown upon Si(100) platforms using ultra-low temperature deposition of highly reactive Ge and Sn hydrides. The device fabrication adopts two new photodiode designs which lead to optimized performance and enables a systematic study of the effects of strain relaxation on emission efficiency. In contrast with n-Ge/i-Ge{sub 1−y}Sn{sub y}/p-Ge analogs, which in most cases contain two defected interfaces, our designs include a p-layer with composition Ge{sub 1−z}Sn{sub z} chosen to be z < y to facilitate light extraction, but with z close enough to y to guarantee no strain relaxation at the i/p interface. In addition, a Ge{sub 1−x}Sn{sub x} alloy is also used for the n layer, with compositions in the 0 ≤ x ≤ y range, so that defected and non-defected n/i interfaces can be studied. The electroluminescence spectra vs the Sn content y in the intrinsic layer of the diodes exhibit a monotonic shift in the emission wavelength from 1550 nm to 2500 nm. On the other hand, the emission intensities show a complex dependence that cannot be explained solely on the basis of Sn concentrations. Detailed theoretical modeling of these intensities makes it possible to extract recombination lifetimes that are found to be more than three times longer in samples in which strain relaxation has not occurred at the n-i interface, demonstrating the existence of a large non-radiative contribution from the relaxation defects. This finding is particularly significant for direct gap diodes with y > 0.09, for which it is practically impossible to avoid strain relaxation in n-Ge/i-Ge{sub 1−y}Sn{sub y}/p-Ge analogs. The new designs introduced here open the door to the fabrication of highly efficient electrically pumped systems for applications in future generations of integrated photonics.

  14. 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. ...

  15. Design and Development of a Flexible Strain Sensor for Textile Structures Based on a Conductive Polymer Composite

    PubMed Central

    Cochrane, Cédric; Koncar, Vladan; Lewandowski, Maryline; Dufour, Claude

    2007-01-01

    The aim of this work is to develop a smart flexible sensor adapted to textile structures, able to measure their strain deformations. The sensors are “smart” because of their capacity to adapt to the specific mechanical properties of textile structures that are lightweight, highly flexible, stretchable, elastic, etc. Because of these properties, textile structures are continuously in movement and easily deformed, even under very low stresses. It is therefore important that the integration of a sensor does not modify their general behavior. The material used for the sensor is based on a thermoplastic elastomer (Evoprene)/carbon black nanoparticle composite, and presents general mechanical properties strongly compatible with the textile substrate. Two preparation techniques are investigated: the conventional melt-mixing process, and the solvent process which is found to be more adapted for this particular application. The preparation procedure is fully described, namely the optimization of the process in terms of filler concentration in which the percolation theory aspects have to be considered. The sensor is then integrated on a thin, lightweight Nylon fabric, and the electromechanical characterization is performed to demonstrate the adaptability and the correct functioning of the sensor as a strain gauge on the fabric. A normalized relative resistance is defined in order to characterize the electrical response of the sensor. Finally, the influence of environmental factors, such as temperature and atmospheric humidity, on the sensor performance is investigated. The results show that the sensor's electrical resistance is particularly affected by humidity. This behavior is discussed in terms of the sensitivity of the carbon black filler particles to the presence of water.

  16. 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.

  17. A Method for Calculating Strain Energy Release Rates in Preliminary Design of Composite Skin/Stringer Debonding Under Multi-Axial Loading

    NASA Technical Reports Server (NTRS)

    Krueger, Ronald; Minguet, Pierre J.; OBrien, T. Kevin

    1999-01-01

    Three simple procedures were developed to determine strain energy release rates, G, in composite skin/stringer specimens for various combinations of unaxial and biaxial (in-plane/out-of-plane) loading conditions. These procedures may be used for parametric design studies in such a way that only a few finite element computations will be necessary for a study of many load combinations. The results were compared with mixed mode strain energy release rates calculated directly from nonlinear two-dimensional plane-strain finite element analyses using the virtual crack closure technique. The first procedure involved solving three unknown parameters needed to determine the energy release rates. Good agreement was obtained when the external loads were used in the expression derived. This superposition technique was only applicable if the structure exhibits a linear load/deflection behavior. Consequently, a second technique was derived which was applicable in the case of nonlinear load/deformation behavior. The technique involved calculating six unknown parameters from a set of six simultaneous linear equations with data from six nonlinear analyses to determine the energy release rates. This procedure was not time efficient, and hence, less appealing. A third procedure was developed to calculate mixed mode energy release rates as a function of delamination lengths. This procedure required only one nonlinear finite element analysis of the specimen with a single delamination length to obtain a reference solution for the energy release rates and the scale factors. The delamination was extended in three separate linear models of the local area in the vicinity of the delamination subjected to unit loads to obtain the distribution of G with delamination lengths. This set of sub-problems was Although additional modeling effort is required to create the sub- models, this local technique is efficient for parametric studies.

  18. Comparative Finite Element Analysis of the Stress-Strain States in Three Different Bonded Solid Oxide Fuel Cell Seal Designs

    SciTech Connect

    Weil, K. Scott; Koeppel, Brian J.

    2008-05-15

    One of the critical issues in designing and fabricating a high performance planar solid oxide fuel cell (pSOFC) stack is the development of the appropriate materials and techniques for hermetically sealing the metal and ceramic components. We are currently developing a foil-based approach that appears to offer good hermeticity and mechanical integrity, while minimizing the generation of interfacial stresses in either of the joint substrate materials, particulary the ceramic cell. Prior experimental work conducted on small-scale samples demonstrated the viability of the concept. Here we present recent results from computational analyses undertaken to investigate potential issues associated with scaling up the seal to full-scale pSOFC stack dimensions/geometry. Here we employ finite element modeling to assess the potential thermal cycling performance of this design, specifically as it pertains to sealing components with vastly different thermal expansion properties.

  19. Large-strain, multiform movements from designable electrothermal actuators based on large highly anisotropic carbon nanotube sheets.

    PubMed

    Li, Qingwei; Liu, Changhong; Lin, Yuan-Hua; Liu, Liang; Jiang, Kaili; Fan, Shoushan

    2015-01-27

    Many electroactive polymer (EAP) actuators use diverse configurations of carbon nanotubes (CNTs) as pliable electrodes to realize discontinuous, agile movements, for CNTs are conductive and flexible. However, the reported CNT-based EAP actuators could only accomplish simple, monotonous actions. Few actuators were extended to complex devices because efficiently preparing a large-area CNT electrode was difficult, and complex electrode design has not been carried out. In this work, we successfully prepared large-area CNT paper (buckypaper, BP) through an efficient approach. The BP is highly anisotropic, strong, and suitable as flexible electrodes. By means of artful graphic design and processing on BP, we fabricated various functional BP electrodes and developed a series of BP-polymer electrothermal actuators (ETAs). The prepared ETAs can realize various controllable movements, such as large-stain bending (>180°), helical curling (∼ 630°), or even bionic actuations (imitating human-hand actions). These functional and interesting movements benefit from flexible electrode design and the anisotropy of BP material. Owing to the advantages of low driving voltage (20-200 V), electrolyte-free and long service life (over 10000 times), we think the ETAs will have great potential applications in the actuator field.

  20. Moderating strain without sacrificing reactivity: design of fast and tunable noncatalyzed alkyne-azide cycloadditions via stereoelectronically controlled transition state stabilization.

    PubMed

    Gold, Brian; Dudley, Gregory B; Alabugin, Igor V

    2013-01-30

    Recently, we have identified two strategies for selective transition state (TS) stabilization in catalyst-free azide/alkyne cycloadditions. In particular, the transition states for the formation of both 1,4- and 1,5-isomers can be stabilized via hyperconjugative assistance for the C···N bond formation, whereas the 1,5-TS can be stabilized via C-H···X H-bonding interactions. When the hyperconjugative assistance is maximized by the antiperiplanar arrangement of propargylic σ-acceptors relative to the forming bonds, the combination of these TS-stabilizing effects was predicted to lead to ~1 million fold acceleration of the cycloaddition with methyl azide. The present work investigated whether hyperconjugative assistance and H-bonding can be combined with strain activation for the design of even more reactive alkynes and whether reactivity can be turned "on demand." When stereoelectronic amplification is achieved by optimal positioning of σ-acceptors at the endocyclic bonds antiperiplanar to the breaking alkyne π-bonds, the stabilization of the bent alkyne geometry leads to a significant decrease in strain in cyclic alkynes without compromising their reactivity in alkyne-azide cycloadditions. The approach can be used in a modular fashion where the TS stabilizing effects are introduced sequentially until the desired level of reactivity is achieved. A significant increase in reactivity upon the protonation of an endocyclic NH-group suggests a new strategy for the design of click reactions triggered by a pH-change or introduction of an external Lewis acid.

  1. Modelling, Design, Growth and Characterization of Strain Balanced Quantum Cascade Lasers (3-11mum), grown by Gas Source Molecular Beam Epitaxy

    NASA Astrophysics Data System (ADS)

    Bandyopadhyay, Neelanjan

    Quantum Cascade Laser (QCL) is a compact room temperature (RT) source of mid-infrared radiation, which can be used for spectroscopic detection of trace amount of chemicals. The mid-infrared spectral range between (3-11 microm), has a dense array of absorption lines of numerous molecules, due to the presence of fundamental vibrational modes. The goal of this thesis can be subdivided into two parts. Firstly, short wavelength QCLs, emitting below 4microm, perform poorly at RT, due to inter-valley Gamma --- L carrier scattering, carrier escape to the continuum, heat removal from the core region at high power density corresponding to short wavelength operation, and large interface scattering due to highly strained materials. Secondly, it is desirable to have a single QCL based source emitting between 6-10microm, which be used to detect multiple molecules having their peak absorptions far apart, inside this spectral range. However, gain bandwidth of a single core QCL is relatively small, so laser emission cannot be tuned over a wide spectral range. This thesis describes the working principle of a QCL based on superlattice transport, rate equations, scattering mechanism, and waveguide design. The choice of the material system for this work and the fundamentals of band structure engineering has been derived. Gas source molecular beam epitaxy - growth optimization and characterization is one of the most important features of this work, especially for short wavelength QCLs, and has been explained in depth. Different strategies for design of active region design of short wavelength QCL and heterogeneous broadband QCL has been explored. The major milestones, of this research was the world's first watt level continuous wave (CW), RT demonstration at 3.76 microm, which was followed by another milestone of the first CW, RT demonstration at 3.39microm and 3.55microm, and finally the elusive result of QCL emitting at CW, RT at a wavelength as short as lambda ~3microm, a record. In

  2. High-Quality Draft Genome Sequence of the Actinobacterium Nocardia terpenica IFM 0406, Producer of the Immunosuppressant Brasilicardins, Using Illumina and PacBio Technologies

    PubMed Central

    Buchmann, Anina; Eitel, Michael; Koch, Pierre; Schwarz, Paul N.; Stegmann, Evi; Wohlleben, Wolfgang; Wolański, Marcin; Krawiec, Michał; Zakrzewska-Czerwińska, Jolanta; Méndez, Carmen; Botas, Alma; Núñez, Luz Elena; Morís, Francisco; Cortés, Jesus

    2016-01-01

    The bacterium Nocardia terpenica IFM 0406 is known as the producer of the immunosuppressant brasilicardin A. Here, we report the completely sequenced genome of strain IFM 0406, which facilitates the heterologous expression of the brasilicardin biosynthetic gene cluster but also unveils the intriguing biosynthetic capacity of the strain to produce secondary metabolites. PMID:27979943

  3. Genome sequence of "Candidatus Microthrix parvicella" Bio17-1, a long-chain-fatty-acid-accumulating filamentous actinobacterium from a biological wastewater treatment plant.

    PubMed

    Muller, Emilie E L; Pinel, Nicolás; Gillece, John D; Schupp, James M; Price, Lance B; Engelthaler, David M; Levantesi, Caterina; Tandoi, Valter; Luong, Khai; Baliga, Nitin S; Korlach, Jonas; Keim, Paul S; Wilmes, Paul

    2012-12-01

    "Candidatus Microthrix" bacteria are deeply branching filamentous actinobacteria which occur at the water-air interface of biological wastewater treatment plants, where they are often responsible for foaming and bulking. Here, we report the first draft genome sequence of a strain from this genus: "Candidatus Microthrix parvicella" strain Bio17-1.

  4. Intradermal application of Aujeszky's disease virus strain Begonia with tocopherol-based adjuvant and a novel design injection device.

    PubMed

    Visser, N; Egger, W; Lütticken, D

    1994-01-01

    Initially the use of intradermal application of Aujeszky's disease vaccines was shown to be very effective. However, for thus far unknown reasons the gI-deleted vaccines were much less efficacious by using this route of vaccination as compared to gI-positive vaccines. By the use of a tocopherol-based adjuvant and an improved design of the intradermal injection device it now appeared feasible to obtain the same efficacy both in specific pathogen free pigs and in pigs with material antibodies as found before when intramuscular administration was performed. With respect to safety we found a complete lack of skin lesions, no adverse systemic reactions (e.g. body temperatures) and no effect on growth rates. Last but not least, the easiness of intradermal injections is of great advantage in large-scale vaccination programs.

  5. Vehicular Causation Factors and Conceptual Design Modifications to Reduce Aortic Strain in Numerically Reconstructed Real World Nearside Lateral Automotive Crashes

    PubMed Central

    Belwadi, Aditya; Yang, King H.

    2015-01-01

    Aortic injury (AI) leading to disruption of the aorta is an uncommon but highly lethal consequence of trauma in modern society. Most recent estimates range from 7,500 to 8,000 cases per year from a variety of causes. It is observed that more than 80% of occupants who suffer an aortic injury die at the scene due to exsanguination into the chest cavity. It is evident that effective means of substantially improving the outcome of motor vehicle crash-induced AIs is by preventing the injury in the first place. In the current study, 16 design of computer experiments (DOCE) were carried out with varying levels of principal direction of force (PDOF), impact velocity, impact height, and impact position of the bullet vehicle combined with occupant seating positions in the case vehicle to determine the effects of these factors on aortic injury. Further, a combination of real world crash data reported in the Crash Injury Research and Engineering Network (CIREN) database, Finite Element (FE) vehicle models, and the Wayne State Human Body Model-II (WSHBM-II) indicates that occupant seating position, impact height, and PDOF, in that order play, a primary role in aortic injury. PMID:26448781

  6. 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.

  7. Non-linear visco-elastic analysis and the design of super-pressure balloons : stress, strain and stability

    NASA Astrophysics Data System (ADS)

    Wakefield, David

    Tensys have a long-established background in the shape generation and load analysis of architectural stressed membrane structures. Founded upon their inTENS finite element analysis suite, these activities have broadened to encompass ‘lighter than air' structures such as aerostats, hybrid air-vehicles and stratospheric balloons. Since 2004 Tensys have acted as consultants to the NASA Ultra Long Duration Balloon (ULDB) Program. Early implementations of the super-pressure balloon design chosen for ULDB have shown problems of geometric instability, characterised by improper deployment and the potential for overall geometric instability once deployed. The latter has been reproduced numerically using inTENS, and the former are better understood following a series of large-scale hangar tests simulating launch and ascent. In both cases the solution lies in minimising the film lobing between the tendons. These tendons, which span between base and apex end fittings, cause the characteristic pumpkin shape of the balloons and also provide valuable constraint against excessive film deformation. There is also the requirement to generate a biaxial stress field in order to mobilise in-plane shear stiffness. A consequence of reduced lobing between tendons is the development of higher stresses in the balloon film under pressure. The different thermal characteristics between tendons and film lead to further significant meridional stress under low temperature flight conditions. The non-linear viscoelastic response of the envelope film acts positively to help dissipate excessive stress and local concentrations. However, creep over time may produce lobe geometry variations sufficient to compromise the geometric stability of the balloon. The design of a balloon requires an analysis approach that addresses the questions of stress and stability over the duration of a flight by time stepping analyses using an appropriate material model. This paper summarises the Dynamic Relaxation

  8. Isolation, identification and characterization of a novel Rhodococcus sp. strain in biodegradation of tetrahydrofuran and its medium optimization using sequential statistics-based experimental designs.

    PubMed

    Yao, Yanlai; Lv, Zhenmei; Min, Hang; Lv, Zhenhua; Jiao, Huipeng

    2009-06-01

    Statistics-based experimental designs were applied to optimize the culture conditions for tetrahydrofuran (THF) degradation by a newly isolated Rhodococcus sp. YYL that tolerates high THF concentrations. Single factor experiments were undertaken for determining the optimum range of each of four factors (initial pH and concentrations of K(2)HPO(4).3H(2)O, NH(4)Cl and yeast extract) and these factors were subsequently optimized using the response surface methodology. The Plackett-Burman design was used to identify three trace elements (Mg(2+), Zn(2+)and Fe(2+)) that significantly increased the THF degradation rate. The optimum conditions were found to be: 1.80 g/L NH(4)Cl, 0.81 g/L K(2)HPO(4).3H(2)O, 0.06 g/L yeast extract, 0.40 g/L MgSO(4).7H(2)O, 0.006 g/L ZnSO(4).7H(2)O, 0.024 g/L FeSO(4).7H(2)O, and an initial pH of 8.26. Under these optimized conditions, the maximum THF degradation rate increased to 137.60 mg THF h(-1) g dry weight in Rhodococcus sp. YYL, which was nearly five times of that by the previously described THF degrading Rhodococcus strain.

  9. Design of Indigenous ELISA Using Tachyzoites from the RH Strain of Toxoplasma gondii and Comparison with Commercial Kits in Ahvaz, Southwest of Iran, 2015

    PubMed Central

    Mohammadpour, Niloofar; Saki, Jasem; Rafiei, Abdollah; Khodadadi, Ali; Tavalla, Mehdi; Cheraghian, Bahman

    2016-01-01

    Background Toxoplasma gondii is one of the most common causes of latent infections in humans worldwide. Detecting anti-Toxoplasma antibodies in serum using serological tests is a common method to diagnose toxoplasmosis. Objectives In the present study, an indigenous ELISA kit was prepared using tachyzoites from the RH strain of T. gondii, and its sensitivity and specificity were compared with those of commercial kits. Methods To produce antigens, 0.02 mL of locally isolated T. gondii RH strain parasites along with 109 tachyzoites were injected into the peritoneal cavities of 50 laboratory mice (BALB/C). Parasites were collected after 4 days. After filtering and washing, the concentration of protein in sonicated tachyzoites was calculated using the Lowry protein assay. The dilution of antigen, serum and alkaline phosphatase conjugate was assessed in designing an indigenous ELISA method; then ELISA was performed based on these dilutions, and its sensitivity was determined using 200 serum samples. In addition, the specificity of the assay was evaluated using 40 serum samples from patients with tuberculosis, leukemia or hydatid cyst. Results Indigenous ELISA was used to examine 100 serum samples containing anti-T. gondii IgG, with a sensitivity of 98% (commercial kits: 100%). Another 100 serum samples containing anti-T. gondii IgM were also tested, with a sensitivity of 99% (commercial kits: 100%). When 40 serum samples from patients with leukemia, hydatid cyst or tuberculosis were examined using anti-T. gondii IgG, the specificity was 100%, identical to commercial kits. However, the specificity of a similar test with anti-T. gondii IgM was just 28.6% for serum samples from leukemia patients, 21.4% for hydatid cyst and 16.7% for tuberculosis. Conclusions We found that purified locally isolated soluble crude antigens of the RH strain of T. gondii from the peritoneal cavity of mice may be one of the most promising antigens for detection of human toxoplasmosis in routine

  10. 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.

  11. Streptomyces malaysiense sp. nov.: A novel Malaysian mangrove soil actinobacterium with antioxidative activity and cytotoxic potential against human cancer cell lines.

    PubMed

    Ser, Hooi-Leng; Palanisamy, Uma Devi; Yin, Wai-Fong; Chan, Kok-Gan; Goh, Bey-Hing; Lee, Learn-Han

    2016-04-13

    Actinobacteria from the unique intertidal ecosystem of the mangroves are known to produce novel, bioactive secondary metabolites. A novel strain known as MUSC 136(T) (=DSM 100712(T) = MCCC 1K01246(T)) which was isolated from Malaysian mangrove forest soil has proven to be no exception. Assessed by a polyphasic approach, its taxonomy showed a range of phylogenetic and chemotaxonomic properties consistent with the genus of Streptomyces. Phylogenetically, highest similarity was to Streptomyces misionensis NBRC 13063(T) (99.6%) along with two other strains (>98.9% sequence similarities). The DNA-DNA relatedness between MUSC 136(T) and these type strains ranged from 22.7 ± 0.5% to 46.5 ± 0.2%. Overall, polyphasic approach studies indicated this strain represents a novel species, for which the name Streptomyces malaysiense sp. nov. is proposed. The potential bioactivities of this strain were explored by means of antioxidant and cytotoxic assays. Intriguingly, MUSC 136(T) exhibited strong antioxidative activities as evaluated by a panel of antioxidant assays. It was also found to possess high cytotoxic effect against HCT-116 cells, which probably mediated through altering p53 protein and intracellular glutathione levels. Chemical analysis of the extract using GC-MS further affirms that the strain produces chemopreventive related metabolites.

  12. Streptomyces malaysiense sp. nov.: A novel Malaysian mangrove soil actinobacterium with antioxidative activity and cytotoxic potential against human cancer cell lines

    PubMed Central

    Ser, Hooi-Leng; Palanisamy, Uma Devi; Yin, Wai-Fong; Chan, Kok-Gan; Goh, Bey-Hing; Lee, Learn-Han

    2016-01-01

    Actinobacteria from the unique intertidal ecosystem of the mangroves are known to produce novel, bioactive secondary metabolites. A novel strain known as MUSC 136T (=DSM 100712T = MCCC 1K01246T) which was isolated from Malaysian mangrove forest soil has proven to be no exception. Assessed by a polyphasic approach, its taxonomy showed a range of phylogenetic and chemotaxonomic properties consistent with the genus of Streptomyces. Phylogenetically, highest similarity was to Streptomyces misionensis NBRC 13063T (99.6%) along with two other strains (>98.9% sequence similarities). The DNA–DNA relatedness between MUSC 136T and these type strains ranged from 22.7 ± 0.5% to 46.5 ± 0.2%. Overall, polyphasic approach studies indicated this strain represents a novel species, for which the name Streptomyces malaysiense sp. nov. is proposed. The potential bioactivities of this strain were explored by means of antioxidant and cytotoxic assays. Intriguingly, MUSC 136T exhibited strong antioxidative activities as evaluated by a panel of antioxidant assays. It was also found to possess high cytotoxic effect against HCT-116 cells, which probably mediated through altering p53 protein and intracellular glutathione levels. Chemical analysis of the extract using GC-MS further affirms that the strain produces chemopreventive related metabolites. PMID:27072394

  13. Mzabimyces algeriensis gen. nov., sp. nov., a halophilic filamentous actinobacterium isolated from a Saharan soil, and proposal of Mzabimycetaceae fam. nov.

    PubMed

    Saker, Rafika; Bouras, Noureddine; Zitouni, Abdelghani; Ghoul, Mostefa; Rohde, Manfred; Schumann, Peter; Spröer, Cathrin; Sabaou, Nasserdine; Klenk, Hans-Peter

    2014-11-01

    Three halophilic mycelium-forming actinobacteria, strains H195(T), H150 and H151, were isolated from a Saharan soil sample collected from Béni-isguen in the Mzab region (Ghardaïa, South of Algeria) and subjected to a polyphasic taxonomic characterisation. These strains were observed to show an aerial mycelium differentiated into coccoid spore chains and fragmented substrate mycelium. Comparative analysis of the 16S rRNA gene sequences revealed that the highest sequence similarities were to Saccharopolyspora qijiaojingensis YIM 91168(T) (92.02 % to H195(T)). Phylogenetic analyses showed that the strains H195(T), H150 and H151 represent a distinct phylogenetic lineage. The cell-wall hydrolysate was found to contain meso-diaminopimelic acid, and the diagnostic whole-cell sugars were identified as arabinose and galactose. The major cellular fatty acids were identified as iso-C15:0, iso-C16:0, iso-C17:0 and anteiso-C17:0. The diagnostic phospholipid detected was phosphatidylcholine and MK-9 (H4) was found to be the predominant menaquinone. The genomic DNA G+C content of strain H195(T) was 68.2 mol%. On the basis of its phenotypic features and phylogenetic position, we propose that strain H195(T) represents a novel genus and species, Mzabimyces algeriensis gen. nov., sp. nov., within a new family, Mzabimycetaceae fam. nov. The type strain of M. algeriensis is strain H195(T) (=DSM 46680(T) = MTCC 12101(T)).

  14. Pseudonocardia adelaidensis sp. nov., an endophytic actinobacterium isolated from the surface-sterilized stem of a grey box tree (Eucalyptus microcarpa).

    PubMed

    Kaewkla, Onuma; Franco, Christopher M M

    2010-12-01

    An aerobic, actinobacterial strain with rod-shaped spores, EUM 221(T) [corrected], which was isolated from the surface-sterilized stem of a grey box tree (Eucalyptus microcarpa), is described. Phylogenetic evaluation based on 16S rRNA gene sequence similarity showed that this isolate belongs to the family Pseudonocardiaceae, with the closest neighbour being Pseudonocardia zijingensis 6330(T) (98.7 %). The level of 16S rRNA gene sequence similarity between the isolate and species of the genus Pseudonocardia with validly published names ranged from 95 to 98 %. Chemotaxonomic data (meso-diaminopimelic acid; major menaquinone MK-8(H(4)); major fatty acid iso-C(16 : 0)) confirmed the affiliation of strain EUM 221(T) [corrected] to the genus Pseudonocardia. The results of the phylogenetic analysis, including physiological and biochemical studies in combination with DNA-DNA hybridization, allowed the genotypic and phenotypic differentiation of strain EUM 221(T) [corrected] from the closest described species. Therefore, this strain represented a novel species and the name proposed is Pseudonocardia adelaidensis sp. nov. The type strain is EUM 221(T) [corrected] (=DSM 45352(T) =ACM 5286(T)).

  15. Achieving high performance electric field induced strain: a rational design of hyperbranched aromatic polyamide functionalized graphene-polyurethane dielectric elastomer composites.

    PubMed

    Chen, Tian; Qiu, Jinhao; Zhu, Kongjun; Li, Jinhuan; Wang, Jingwen; Li, Shuqin; Wang, Xiaoliang

    2015-03-26

    Dielectric elastomers have great potentials as flexible actuators in micro-electromechanical systems (MEMS) due to their large deformation, light weight, mechanical compliancy, and low cost. The low dielectric constant of these elastomers requires a rather high voltage electric field, which has greatly limited their applications. In this work, a diaphragm-type flexible microactuator comprising a hyperbranched aromatic polyamide functionalized graphene (HAPFG) filler embedded into the polyurethane (PU) dielectric elastomer matrix is described. The rational designed HAPFG sheets exhibits uniform dispersion in PU matrix and strong adhesion with the matrix by hydrogen-bond coupling. Consequently, the HAPFG-PU composites possess high dielectric performance and low loss modulus. The effect of hyperbranched aromatic polyamide functionalized graphene on high voltage electric field induced strain was experimentally investigated using the Fotonic sensor. The high electric field response of the composite was discussed by applying different kinds of alternating-current field. In addition, a comparison of the breakdown strength between the HAPFG-PU composite and the pure PU was carried out.

  16. Arthrobacter pokkalii sp nov, a Novel Plant Associated Actinobacterium with Plant Beneficial Properties, Isolated from Saline Tolerant Pokkali Rice, Kerala, India

    PubMed Central

    Krishnan, Ramya; Menon, Rahul Ravikumar; Tanaka, Naoto; Busse, Hans-Jürgen; Krishnamurthi, Srinivasan; Rameshkumar, Natarajan

    2016-01-01

    A novel yellow colony-forming bacterium, strain P3B162T was isolated from the pokkali rice rhizosphere from Kerala, India, as part of a project study aimed at isolating plant growth beneficial rhizobacteria from saline tolerant pokkali rice and functionally evaluate their abilities to promote plant growth under saline conditions. The novel strain P3B162T possesses plant growth beneficial traits such as positive growth on 1-aminocyclopropane-1-carboxylic acid (ACC), production of indole acetic acid (IAA) and siderophore. In addition, it also showed important phenotypic characters such as ability to form biofilm and utilization of various components of plant root exudates (sugars, amino acids and organic acids), clearly indicating its lifestyle as a plant rhizosphere associated bacterium. Taxonomically, the novel strain P3B162T was affiliated to the genus Arthrobacter based on the collective results of phenotypic, genotypic and chemotaxonomic analyses. Moreover, molecular analysis using 16S rRNA gene showed Arthrobacter globiformis NBRC 12137T, Arthrobacter pascens DSM 20545T and Arthrobacter liuii DSXY973T as the closely related phylogenetic neighbours, showing more than 98% 16S rRNA similarity values, whereas the recA gene analysis displayed Arthrobacter liuii JCM 19864T as the nearest neighbour with 94.7% sequence similarity and only 91.7% to Arthrobacter globiformis LMG 3813T and 88.7% to Arthrobacter pascens LMG 16255T. However, the DNA-DNA hybridization values between strain P3B162T, Arthrobacter globiformis LMG 3813T, Arthrobacter pascens LMG 16255T and Arthrobacter liuii JCM 19864T was below 50%. In addition, the novel strain P3B162T can be distinguished from its closely related type strains by several phenotypic characters such as colony pigment, tolerance to NaCl, motility, reduction of nitrate, hydrolysis of DNA, acid from sucrose, cell wall sugars and cell wall peptidoglycan structure. In conclusion, the combined results of this study support the

  17. 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.

  18. Geomechanical Modeling of CO2 Injection Site to Predict Wellbore Stresses and Strains for the Design of Wellbore Seal Repair Materials

    NASA Astrophysics Data System (ADS)

    Sobolik, S. R.; Gomez, S. P.; Matteo, E. N.; Stormont, J.

    2014-12-01

    This paper will present the results of large-scale three-dimensional calculations simulating the hydrological-mechanical behavior of a CO2injection reservoir and the resulting effects on wellbore casings and sealant repair materials. A critical aspect of designing effective wellbore seal repair materials is predicting thermo-mechanical perturbations in local stress that can compromise seal integrity. The DOE-NETL project "Wellbore Seal Repair Using Nanocomposite Materials," is interested in the stress-strain history of abandoned wells, as well as changes in local pressure, stress, and temperature conditions that accompany carbon dioxide injection or brine extraction. Two distinct computational models comprise the current modeling effort. The first is a field scale model that uses the stratigraphy, material properties, and injection history from a pilot CO2injection operation in Cranfield, MS to develop a stress-strain history for wellbore locations from 100 to 400 meters from an injection well. The results from the field scale model are used as input to a more detailed model of a wellbore casing. The 3D wellbore model examines the impacts of various loading scenarios on a casing structure. This model has been developed in conjunction with bench-top experiments of an integrated seal system in an idealized scaled wellbore mock-up being used to test candidate seal repair materials. The results from these models will be used to estimate the necessary mechanical properties needed for a successful repair material. This material is based upon work supported by the US Department of Energy (DOE) National Energy Technology Laboratory (NETL) under Grant Number DE-FE0009562. This project is managed and administered by the Storage Division of the NETL and funded by DOE/NETL and cost-sharing partners. This work was funded in part by the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science

  19. Geomechanical Modeling of CO2 Injection Site to Predict Wellbore Stresses and Strains for the Design of Wellbore Seal Repair Materials

    NASA Astrophysics Data System (ADS)

    Sobolik, S. R.; Matteo, E. N.; Dewers, T. A.; Newell, P.; Gomez, S. P.; Stormont, J.

    2014-12-01

    This paper will present the results of large-scale three-dimensional calculations simulating the hydrological-mechanical behavior of a CO2 injection reservoir and the resulting effects on wellbore casings and sealant repair materials. A critical aspect of designing effective wellbore seal repair materials is predicting thermo-mechanical perturbations in local stress that can compromise seal integrity. The DOE-NETL project "Wellbore Seal Repair Using Nanocomposite Materials," is interested in the stress-strain history of abandoned wells, as well as changes in local pressure, stress, and temperature conditions that accompany carbon dioxide injection or brine extraction. Two distinct computational models comprise the current modeling effort. The first is a field scale model that uses the stratigraphy, material properties, and injection history from a pilot CO2 injection operation in Cranfield, MS to develop a stress-strain history for wellbore locations from 100 to 400 meters from an injection well. The results from the field scale model are used as input to a more detailed model of a wellbore casing. The 3D wellbore model examines the impacts of various loading scenarios on a casing structure. This model has been developed in conjunction with bench-top experiments of an integrated seal system in an idealized scaled wellbore mock-up being used to test candidate seal repair materials. The results from these models will be used to estimate the necessary mechanical properties needed for a successful repair material. This material is based upon work supported by the U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) under Grant Number DE-FE0009562. This project is managed and administered by the University of New Mexico and funded by DOE/NETL and cost-sharing partners. This work was funded in part by the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of

  20. Geomechanical Modeling of CO2 Injection Site to Predict Wellbore Stresses and Strains for the Design of Wellbore Seal Repair Materials

    NASA Astrophysics Data System (ADS)

    Sobolik, S. R.; Gomez, S. P.; Matteo, E. N.; Stormont, J.

    2015-12-01

    This paper will present the results of large-scale three-dimensional calculations simulating the hydrological-mechanical behavior of a CO2injection reservoir and the resulting effects on wellbore casings and sealant repair materials. A critical aspect of designing effective wellbore seal repair materials is predicting thermo-mechanical perturbations in local stress that can compromise seal integrity. The DOE-NETL project "Wellbore Seal Repair Using Nanocomposite Materials," is interested in the stress-strain history of abandoned wells, as well as changes in local pressure, stress, and temperature conditions that accompany carbon dioxide injection or brine extraction. Two distinct computational models comprise the current modeling effort. The first is a field scale model that uses the stratigraphy, material properties, and injection history from a pilot CO2injection operation in Cranfield, MS to develop a stress-strain history for wellbore locations from 100 to 400 meters from an injection well. The results from the field scale model are used as input to a more detailed model of a wellbore casing. The 3D wellbore model examines the impacts of various loading scenarios on a casing structure. This model has been developed in conjunction with bench-top experiments of an integrated seal system in an idealized scaled wellbore mock-up being used to test candidate seal repair materials. The results from these models will be used to estimate the necessary mechanical properties needed for a successful repair material. This material is based upon work supported by the US Department of Energy (DOE) National Energy Technology Laboratory (NETL) under Grant Number DE-FE0009562. This project is managed and administered by the Storage Division of the NETL and funded by DOE/NETL and cost-sharing partners. This work was funded in part by the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science

  1. Improvement of LysM-Mediated Surface Display of Designed Ankyrin Repeat Proteins (DARPins) in Recombinant and Nonrecombinant Strains of Lactococcus lactis and Lactobacillus Species

    PubMed Central

    Zadravec, Petra; Štrukelj, Borut

    2015-01-01

    Safety and probiotic properties make lactic acid bacteria (LAB) attractive hosts for surface display of heterologous proteins. Protein display on nonrecombinant microorganisms is preferred for therapeutic and food applications due to regulatory requirements. We displayed two designed ankyrin repeat proteins (DARPins), each possessing affinity for the Fc region of human IgG, on the surface of Lactococcus lactis by fusing them to the Usp45 secretion signal and to the peptidoglycan-binding C terminus of AcmA, containing lysine motif (LysM) repeats. Growth medium containing a secreted fusion protein was used to test its heterologous binding to 10 strains of species of the genus Lactobacillus, using flow cytometry, whole-cell enzyme-linked immunosorbent assay (ELISA), and fluorescence microscopy. The fusion proteins bound to the surfaces of all lactobacilli; however, binding to the majority of bacteria was only 2- to 5-fold stronger than that of the control. Lactobacillus salivarius ATCC 11741 demonstrated exceptionally strong binding (32- to 55-fold higher than that of the control) and may therefore be an attractive host for nonrecombinant surface display. Genomic comparison of the species indicated the exopolysaccharides of Lb. salivarius as a possible reason for the difference. Additionally, a 15-fold concentration-dependent increase in nonrecombinant surface display on L. lactis was demonstrated by growing bacteria with sublethal concentrations of the antibiotics chloramphenicol and erythromycin. Nonrecombinant surface display on LAB, based on LysM repeats, was optimized by selecting Lactobacillus salivarius ATCC 11741 as the optimal host and by introducing antibiotics as additives for increasing surface display on L. lactis. Additionally, effective display of DARPins on the surfaces of nonrecombinant LAB has opened up several new therapeutic possibilities. PMID:25576617

  2. Improvement of LysM-mediated surface display of designed ankyrin repeat proteins (DARPins) in recombinant and nonrecombinant strains of Lactococcus lactis and Lactobacillus Species.

    PubMed

    Zadravec, Petra; Štrukelj, Borut; Berlec, Aleš

    2015-03-01

    Safety and probiotic properties make lactic acid bacteria (LAB) attractive hosts for surface display of heterologous proteins. Protein display on nonrecombinant microorganisms is preferred for therapeutic and food applications due to regulatory requirements. We displayed two designed ankyrin repeat proteins (DARPins), each possessing affinity for the Fc region of human IgG, on the surface of Lactococcus lactis by fusing them to the Usp45 secretion signal and to the peptidoglycan-binding C terminus of AcmA, containing lysine motif (LysM) repeats. Growth medium containing a secreted fusion protein was used to test its heterologous binding to 10 strains of species of the genus Lactobacillus, using flow cytometry, whole-cell enzyme-linked immunosorbent assay (ELISA), and fluorescence microscopy. The fusion proteins bound to the surfaces of all lactobacilli; however, binding to the majority of bacteria was only 2- to 5-fold stronger than that of the control. Lactobacillus salivarius ATCC 11741 demonstrated exceptionally strong binding (32- to 55-fold higher than that of the control) and may therefore be an attractive host for nonrecombinant surface display. Genomic comparison of the species indicated the exopolysaccharides of Lb. salivarius as a possible reason for the difference. Additionally, a 15-fold concentration-dependent increase in nonrecombinant surface display on L. lactis was demonstrated by growing bacteria with sublethal concentrations of the antibiotics chloramphenicol and erythromycin. Nonrecombinant surface display on LAB, based on LysM repeats, was optimized by selecting Lactobacillus salivarius ATCC 11741 as the optimal host and by introducing antibiotics as additives for increasing surface display on L. lactis. Additionally, effective display of DARPins on the surfaces of nonrecombinant LAB has opened up several new therapeutic possibilities.

  3. Design and performance investigation of a highly accurate apodized fiber Bragg grating-based strain sensor in single and quasi-distributed systems.

    PubMed

    Ali, Taha A; Shehata, Mohamed I; Mohamed, Nazmi A

    2015-06-01

    In this work, fiber Bragg grating (FBG) strain sensors in single and quasi-distributed systems are investigated, seeking high-accuracy measurement. Since FBG-based strain sensors of small lengths are preferred in medical applications, and that causes the full width at half-maximum (FWHM) to be larger, a new apodization profile is introduced for the first time, to the best of our knowledge, with a remarkable FWHM at small sensor lengths compared to the Gaussian and Nuttall profiles, in addition to a higher mainlobe slope at these lengths. A careful selection of apodization profiles with detailed investigation is performed-using sidelobe analysis and the FWHM, which are primary judgment factors especially in a quasi-distributed configuration. A comparison between the elite selection of apodization profiles (extracted from related literature) and the proposed new profile is carried out covering the reflectivity peak, FWHM, and sidelobe analysis. The optimization process concludes that the proposed new profile with a chosen small length (L) of 10 mm and Δnac of 1.4×10-4 is the optimum choice for single stage and quasi-distributed strain-sensor networks, even better than the Gaussian profile at small sensor lengths. The proposed profile achieves the smallest FWHM of 15 GHz (suitable for UDWDM), and the highest mainlobe slope of 130 dB/nm. For the quasi-distributed scenario, a noteworthy high isolation of 6.953 dB is achieved while applying a high strain value of 1500 μstrain (με) for a five-stage strain-sensing network. Further investigation was undertaken, proving that consistency in choosing the apodization profile in the quasi-distributed network is mandatory. A test was made of the inclusion of a uniform apodized sensor among other apodized sensors with the proposed profile in an FBG strain-sensor network.

  4. Lipid storage in high-altitude Andean Lakes extremophiles and its mobilization under stress conditions in Rhodococcus sp. A5, a UV-resistant actinobacterium.

    PubMed

    Bequer Urbano, Susana; Albarracín, Virginia H; Ordoñez, Omar F; Farías, María E; Alvarez, Héctor M

    2013-03-01

    The production of triacylglycerols (TAG) or wax esters (WS) seems to be a widespread feature among extremophile bacteria living in high-altitude Andean Lakes (HAAL), Argentina. Twelve out of twenty bacterial strains isolated from HAAL were able to produce TAG or WS (between 2 and 17 % of cellular dry weight) under nitrogen-limiting culture conditions. Among these strains, the extremophile Rhodococcus sp. A5 accumulated significant amounts of TAG during growth on glucose (17 %, CDW) and hexadecane (32 %, CDW) as sole carbon sources. The role of accumulated TAG in the response to carbon starvation, osmotic stress, UV-radiation and desiccation was investigated in Rhodococcus sp. A5 using an inhibitor of TAG degradation. Cells degraded TAG during these stresses in the absence of the inhibitor. The inhibition of TAG mobilization affected cell survival during osmotic stress only during the initial growth stage. Little or no surviving cells were observed after carbon starvation, UV-treatment and desiccation, when TAG mobilization was inhibited. These results suggested that TAG metabolism is relevant for the adaptation and survival of A5 cells under carbon starvation, osmotic stress and UV irradiation, and essential under desiccation conditions, which prevail in HAAL environments.

  5. The actinobacterium Microbacterium sp. 16SH accepts pBBR1-based pPROBE vectors, forms biofilms, invades roots, and fixes N₂ associated with micropropagated sugarcane plants.

    PubMed

    Lin, Li; Guo, Wei; Xing, Yongxiu; Zhang, Xincheng; Li, Zhengyi; Hu, Chunjin; Li, Song; Li, Yangrui; An, Qianli

    2012-02-01

    Members of the genus Microbacterium lineage of Gram-positive actinobacteria are increasingly being reported to display significant traits associated with environmental biotechnology and bioengineering. 16SH is a nitrogen-fixing bacterial strain isolated from a surface-sterilized stem of sugarcane grown in Guangxi, China. Analysis of 16S rRNA gene sequences revealed that 16SH belonged to the genus Microbacterium. pPROBE-pTet(r) plasmids were constructed by cloning the promoter region of the Tet(r) gene into the promoterless pPROBE-AT, -OT, and -TT vectors derived from the pBBR1 plasmid that has a broad host range of Gram-negative bacteria and sequence similarities to plasmids from Gram-positive bacteria. The pPROBE-pTet(r) plasmids expressed the gfp reporter gene and were stably maintained in 16SH cells without antibiotic selection in free-living state and in planta. Confocal microscopy on intact roots of micropropagated sugarcane plantlets showed that gfp-tagged 16SH cells formed biofilms on root maturation and elongation zones but not on root meristem zones and root caps, and colonized in intercellular spaces of root cortices. Inoculation of 16SH significantly increased biomass and nitrogen content of micropropagated sugarcane seedlings grown with a nitrogen fertilization of 6.3 mg N/kg soil. ¹⁵N isotope dilution assays demonstrated that biological nitrogen fixation contributed to this plant growth promotion. This study for the first time demonstrated that the pBBR1-based pPROBE plasmids provided an efficient genetic transfer system for a Gram-positive Microbacterium strain, and that a nitrogen-fixing Microbacterium endophyte colonized in intact host plants and fixed N₂ associated with the host plants.

  6. 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

  7. Strain gage system evaluation program

    NASA Technical Reports Server (NTRS)

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

    1978-01-01

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

  8. Design Considerations for Monolithic Beam Formers Based on Electro-Optic Polymer Phase Modulators and Strain-Induced Optical Waveguides - Postprint

    DTIC Science & Technology

    2015-01-01

    passive optical polymer is that it can provide low-loss optical waveguides and its mode can be made to match that of a 4.0~4.5 m small-core fiber ...on top of the polymer introduces a strain-induced refractive index change within the core layer thus providing better lateral optical mode ...induced optical waveguide technique to reduce optical propagation loss, 4) the TO switch in closely spaced parallel single- mode waveguides, and 5

  9. A multi-channel bioluminescent bacterial biosensor for the on-line detection of metals and toxicity. Part I: design and optimization of bioluminescent bacterial strains.

    PubMed

    Charrier, Thomas; Durand, Marie-José; Jouanneau, Sulivan; Dion, Michel; Pernetti, Mimma; Poncelet, Denis; Thouand, Gérald

    2011-05-01

    This study describes the construction of inducible bioluminescent strains via genetic engineering along with their characterization and optimization in the detection of heavy metals. Firstly, a preliminary comparative study enabled us to select a suitable carbon substrate from pyruvate, glucose, citrate, diluted Luria-Bertani, and acetate. The latter carbon source provided the best induction ratios for comparison. Results showed that the three constructed inducible strains, Escherichia coli DH1 pBzntlux, pBarslux, and pBcoplux, were usable when conducting a bioassay after a 14-h overnight culture at 30 °C. Utilizing these sensors gave a range of 12 detected heavy metals including several cross-detections. Detection limits for each metal were often close to and sometimes lower than the European standards for water pollution. Finally, in order to maintain sensitive bacteria within the future biosensor-measuring cell, the agarose immobilization matrix was compared to polyvinyl alcohol (PVA). Agarose was selected because the detection limits of the bioluminescent strains were not affected, in contrast to PVA. Specific detection and cross-detection ranges determined in this study will form the basis of a multiple metals detection system by the new multi-channel Lumisens3 biosensor.

  10. [Designing of hybrid human interferon alfa-2 strain-producers and the use of enteropeptidase for obtaining N-terminal methionine-free interferons].

    PubMed

    Shirokov, D A; Riabichenko, V V; Akishina, R I; Ospel'nikova, T P; Glazunov, A V; Chestukhina, G G; Veĭko, V P

    2011-01-01

    A system for production of human interferon-alpha2a (IFN-alpha2a) and IFN-alpha2b lacking N-terminal methionine has been developed. Plasmids containing genes of hybrid IFN-alpha2 under the control of different promoters were constructed; a sequence encoding the enteropeptidase hydrolysis site being introduced in proximal part of the genes. As the result, 4 strains of Escherichia coli producing hybrid IFN-alpha2 have been obtained. The methodology for IFN-alpha2 renaturation, hydrolysis of its N-terminal part, chromatographic purification of N-terminal methionine-free IFN-alpha2 has been developed.

  11. Design.

    ERIC Educational Resources Information Center

    Online-Offline, 1998

    1998-01-01

    Provides an annotated bibliography of resources on this month's theme "Design" for K-8 language arts, art and architecture, music and dance, science, math, social studies, health, and physical education. Includes Web sites, CD-ROMs and software, videos, books, audiotapes, magazines, professional resources and classroom activities.…

  12. Design

    ERIC Educational Resources Information Center

    Buchanan, Richard; Cross, Nigel; Durling, David; Nelson, Harold; Owen, Charles; Valtonen, Anna; Boling, Elizabeth; Gibbons, Andrew; Visscher-Voerman, Irene

    2013-01-01

    Scholars representing the field of design were asked to identify what they considered to be the most exciting and imaginative work currently being done in their field, as well as how that work might change our understanding. The scholars included Richard Buchanan, Nigel Cross, David Durling, Harold Nelson, Charles Owen, and Anna Valtonen. Scholars…

  13. 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.

  14. 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.

  15. Construction of an Optical Fiber Strain Gauge

    NASA Astrophysics Data System (ADS)

    Sulaiman, Najwa

    This project is focused on the construction of an optical fiber strain gauge that is based on a strain 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 strain experienced by the cantilever. I describe the design and construction of our optical fiber strain gauge as well as the characterization of different parts of the apparatus.

  16. 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 ( ...

  17. 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 ...

  18. The Actinobacterium Corynebacterium glutamicum, an Industrial Workhorse.

    PubMed

    Lee, Joo-Young; Na, Yoon-Ah; Kim, Eungsoo; Lee, Heung-Shick; Kim, Pil

    2016-05-28

    Starting as a glutamate producer, Corynebacterium glutamicum has played a variety of roles in the industrial production of amino acids, one of the most important areas of white biotechnology. From shortly after its genome information became available, C. glutamicum has been applied in various production processes for value-added chemicals, fuels, and polymers, as a key organism in industrial biotechnology alongside the surprising progress in systems biology and metabolic engineering. In addition, recent studies have suggested another potential for C. glutamicum as a synthetic biology platform chassis that could move the new era of industrial microbial biotechnology beyond the classical field. Here, we review the recent progress and perspectives in relation to C. glutamicum, which demonstrate it as one of the most promising and valuable workhorses in the field of industrial biotechnology.

  19. Pulsed Phase-Locked-Loop Strain Monitor

    NASA Technical Reports Server (NTRS)

    Heyman, J. S.; Stone, F. D.

    1982-01-01

    P2sup.L2sup. strain monitor measures strain 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.

  20. Medically Complex Home Care and Caregiver Strain

    ERIC Educational Resources Information Center

    Moorman, Sara M.; Macdonald, Cameron

    2013-01-01

    Purpose of the study: To examine (a) whether the content of caregiving tasks (i.e., nursing vs. personal care) contributes to variation in caregivers' strain and (b) whether the level of complexity of nursing tasks contributes to variation in strain among caregivers providing help with such tasks. Design and methods: The data came from the Cash…

  1. Superlattice strain gage

    DOEpatents

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

    1988-06-28

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

  2. 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.

  3. Involvement of an alkane hydroxylase system of Gordonia sp. strain SoCg in degradation of solid n-alkanes.

    PubMed

    Lo Piccolo, Luca; De Pasquale, Claudio; Fodale, Roberta; Puglia, Anna Maria; Quatrini, Paola

    2011-02-01

    Enzymes involved in oxidation of long-chain n-alkanes are still not well known, especially those in gram-positive bacteria. This work describes the alkane degradation system of the n-alkane degrader actinobacterium Gordonia sp. strain SoCg, which is able to grow on n-alkanes from dodecane (C(12)) to hexatriacontane (C(36)) as the sole C source. SoCg harbors in its chromosome a single alk locus carrying six open reading frames (ORFs), which shows 78 to 79% identity with the alkane hydroxylase (AH)-encoding systems of other alkane-degrading actinobacteria. Quantitative reverse transcription-PCR showed that the genes encoding AlkB (alkane 1-monooxygenase), RubA3 (rubredoxin), RubA4 (rubredoxin), and RubB (rubredoxin reductase) were induced by both n-hexadecane and n-triacontane, which were chosen as representative long-chain liquid and solid n-alkane molecules, respectively. Biotransformation of n-hexadecane into the corresponding 1-hexadecanol was detected by solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME/GC-MS) analysis. The Gordonia SoCg alkB was heterologously expressed in Escherichia coli BL21 and in Streptomyces coelicolor M145, and both hosts acquired the ability to transform n-hexadecane into 1-hexadecanol, but the corresponding long-chain alcohol was never detected on n-triacontane. However, the recombinant S. coelicolor M145-AH, expressing the Gordonia alkB gene, was able to grow on n-triacontane as the sole C source. A SoCg alkB disruption mutant that is completely unable to grow on n-triacontane was obtained, demonstrating the role of an AlkB-type AH system in degradation of solid n-alkanes.

  4. Optimization of Crude Oil and PAHs Degradation by Stenotrophomonas rhizophila KX082814 Strain through Response Surface Methodology Using Box-Behnken Design

    PubMed Central

    Virupakshappa, Praveen Kumar Siddalingappa; Mishra, Gaurav; Mehkri, Mohammed Ameenuddin

    2016-01-01

    The present paper describes the process optimization study for crude oil degradation which is a continuation of our earlier work on hydrocarbon degradation study of the isolate Stenotrophomonas rhizophila (PM-1) with GenBank accession number KX082814. Response Surface Methodology with Box-Behnken Design was used to optimize the process wherein temperature, pH, salinity, and inoculum size (at three levels) were used as independent variables and Total Petroleum Hydrocarbon, Biological Oxygen Demand, and Chemical Oxygen Demand of crude oil and PAHs as dependent variables (response). The statistical analysis, via ANOVA, showed coefficient of determination R2 as 0.7678 with statistically significant P value 0.0163 fitting in second-order quadratic regression model for crude oil removal. The predicted optimum parameters, namely, temperature, pH, salinity, and inoculum size, were found to be 32.5°C, 9, 12.5, and 12.5 mL, respectively. At this optimum condition, the observed and predicted PAHs and crude oil removal were found to be 71.82% and 79.53% in validation experiments, respectively. The % TPH results correlate with GC/MS studies, BOD, COD, and TPC. The validation of numerical optimization was done through GC/MS studies and % removal of crude oil. PMID:28116165

  5. Optimization of Crude Oil and PAHs Degradation by Stenotrophomonas rhizophila KX082814 Strain through Response Surface Methodology Using Box-Behnken Design.

    PubMed

    Virupakshappa, Praveen Kumar Siddalingappa; Krishnaswamy, Manjunatha Bukkambudhi; Mishra, Gaurav; Mehkri, Mohammed Ameenuddin

    2016-01-01

    The present paper describes the process optimization study for crude oil degradation which is a continuation of our earlier work on hydrocarbon degradation study of the isolate Stenotrophomonas rhizophila (PM-1) with GenBank accession number KX082814. Response Surface Methodology with Box-Behnken Design was used to optimize the process wherein temperature, pH, salinity, and inoculum size (at three levels) were used as independent variables and Total Petroleum Hydrocarbon, Biological Oxygen Demand, and Chemical Oxygen Demand of crude oil and PAHs as dependent variables (response). The statistical analysis, via ANOVA, showed coefficient of determination R(2) as 0.7678 with statistically significant P value 0.0163 fitting in second-order quadratic regression model for crude oil removal. The predicted optimum parameters, namely, temperature, pH, salinity, and inoculum size, were found to be 32.5°C, 9, 12.5, and 12.5 mL, respectively. At this optimum condition, the observed and predicted PAHs and crude oil removal were found to be 71.82% and 79.53% in validation experiments, respectively. The % TPH results correlate with GC/MS studies, BOD, COD, and TPC. The validation of numerical optimization was done through GC/MS studies and % removal of crude oil.

  6. 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.

  7. Can a strain yield a qubit?

    NASA Astrophysics Data System (ADS)

    Benjamin, Colin

    2015-03-01

    A Josepshon qubit is designed via the application of a tensile strain to a topological insulator surface, sandwiched between two s-wave superconductors. The strain applied leads to a shift in Dirac point without changing the conducting states existing on the surface of a topological insulator. This strain 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 strain. 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.

  8. 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 ...

  9. Elastocaloric cooling processes: The influence of material strain and strain rate on efficiency and temperature span

    NASA Astrophysics Data System (ADS)

    Schmidt, Marvin; Schütze, Andreas; Seelecke, Stefan

    2016-06-01

    This paper discusses the influence of material strain and strain 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 strains and strain 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.

  10. Heterogeneity of inelastic strain during creep of Carrara marble: Microscale strain measurement technique

    NASA Astrophysics Data System (ADS)

    Quintanilla-Terminel, Alejandra; Evans, Brian

    2016-08-01

    We combined the split cylinder technique with microfabrication technology to observe strain 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 strain measurement (MSSM) technique described here allowed us to analyze the local strain distribution with unprecedented detail over large regions. The description of the strain field is a function of the area over which strain is being computed. The scale at which the strain 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 strained bands that span several grains. One possible cause for the multigrain bands is the need to relieve strain incompatibilities that result when twins impinge on neighboring grains. At 600-700°C, the strain fields are still quite heterogeneous, and local strain 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 strain 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 strains normalized by the total strain; thus, we conclude that the microstructure does not achieve a steady state in this strain interval.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. The Development of Electrical Strain Gages

    NASA Technical Reports Server (NTRS)

    De Forest, A V; Leaderman, H

    1940-01-01

    The design, construction, and properties of an electrical-resistance strain 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 strain gage, together with instrument problems, is discussed.

  16. 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.

  17. A natural vaccine candidate strain against cholera.

    PubMed

    Liu, Y Q; Qi, G M; Wang, S X; Yu, Y M; Duan, G C; Zhang, L J; Gao, S Y

    1995-12-01

    E1 Tor Vibrio cholerae (EVC) strains may be classified into two kinds-epidemigenic (EEVC) strains and non-epidemigenic (NEEVC) strains-based on a phage-biotyping system. A large number of EEVC strains have been screened for toxigenic and putative colonization attributes. One such naturally occurring strains (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 strain and does not cause fluid accumulation in rabbit ilcal loop tests. Active immunization of rabbits with strain IEM101 elicited good protection against challenge with virulent strains 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.

  18. 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.

  19. 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.

  20. Screening of flocculant-producing strains by NTG mutagenesis.

    PubMed

    Huang, Xiao-Wu; Cheng, Wen; Hu, Yong-You

    2005-01-01

    Screening of new microorganism being able to produce efficiently flocculants was carried out. A new model for screening efficient flocculant-producing strains was designed and tested. The results showed that this model for screening efficient flocculant-producing strains is very reliable and can greatly shorten the screening period. 13 flocculant-producing strains were isolated from activated sludge by conventional method. A strain, designated as HHE6, produced the bioflocculant with the turbidity removal 98% for kaolin suspension. Six of 13 strains selected as the original strains were treated with NTG as mutagen, and five mutant strains (HHE-P7, HHE-A8, HHE-P21, HHE-P24, HHE-A26) with high flocculation efficiency was obtained by selection, which exhibited the flocculation rate for kaolin suspension above 90%. Strains HHE6, HHE-P7, and HHE-P24 were classified as Penicillium purpurogenum, HHE-P21 as Penicillium cyclopium, HHE-A26 as Aspergillus versicolor and HHE-A8 as Aspergillus fumigatus, and it is hitherto unreported for biofloccutant-producing strains of Penicillium. The growth of the six strains (HHE6, HHE-P7, HHE-A8, HHE-P21, HHE-P24, HHE-A26) had similar curves, i.e. firstly increasing rapidly, keeping relatively constant then and finally decreasing gradually with cultivation time. The production of bioflocculants by strains showed the similar pattern to strain growth.

  1. Si1-yGey or Ge1-zSnz Source/Drain Stressors on Strained Si1-xGex-Channel P-Type Field-Effect Transistors: A Technology Computer-Aided Design Study

    NASA Astrophysics Data System (ADS)

    Eneman, Geert; De Keersgieter, An; Witters, Liesbeth; Mitard, Jerome; Vincent, Benjamin; Hikavyy, Andriy; Loo, Roger; Horiguchi, Naoto; Collaert, Nadine; Thean, Aaron

    2013-04-01

    The interaction between two stress techniques, strain-relaxed buffers (SRBs) and epitaxial source/drain stressors, is studied on short, Si1-xGex- and Ge-channel planar transistors. This work focuses on the longitudinal channel stress generated by these two techniques. Unlike for unstrained silicon-channel transistors, for strained channels on top of a strain-relaxed buffer a source/drain stressor without recess generates similar longitudinal channel stress than source/drain stressors with a deep recess. The least efficient stress transfer is obtained for source/drain stressors with a small recess that removes only the strained channel, not the substrate underneath. These trends are explained by a trade-off between elastic relaxation of the strained-channel during source/drain recess and the increased stress generation of thicker source/drain stressors. For Ge-channel pFETs, GeSn source/drains and Si1-xGex strain-relaxed buffers are efficient stressors for mobility enhancement. The former is more efficient for gate-last schemes than for gate-first, while the stress generated by the SRB is found to be independent of the gate-scheme.

  2. Imploding Liner Material Strength Measurements at High-Strain and High Strain Rate

    SciTech Connect

    Bartsch, R.R.; Lee, H.; Holtkamp, D.; Wright, B.; Stokes, J.; Morgan, D.; Anderson, W.; Broste, W.

    1998-10-18

    Imploding, cylindrical liners provide a unique, shockless means of simultaneously accessing high strain and high-strain-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. Strains of up to {approximately}1.25 and strain 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 strain, strain-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 strains 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 strain and strain-rate heating. The liner configuration and pyrometry diagnostic will also be discussed.

  3. 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.

  4. Thin film strain gage development program

    NASA Technical Reports Server (NTRS)

    Grant, H. P.; Przybyszewski, J. S.; Anderson, W. L.; Claing, R. G.

    1983-01-01

    Sputtered thin-film dynamic strain 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 strain-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 strain gage installations, and any alteration of the aerodynamic, thermal, or structural performance of the blade is correspondingly reduced, dynamic strain 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.

  5. Heat strain during explosive ordnance disposal.

    PubMed

    Stewart, Ian B; Rojek, Amanda M; Hunt, Andrew P

    2011-08-01

    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 strain in bomb technicians. Six participants undertook simulated operational tasks across 2 days of variable climate. All subjects demonstrated high levels of heat strain as evidenced by elevated heart rate, core body temperature, and physiological strain 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 strain 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.

  6. 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 ...

  7. 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.

  8. Test load verification through strain data analysis

    NASA Technical Reports Server (NTRS)

    Verderaime, V.; Harrington, F.

    1995-01-01

    A traditional binding acceptance criterion on polycrystalline structures is the experimental verification of the ultimate factor of safety. At fracture, the induced strain is inelastic and about an order-of-magnitude greater than designed for maximum expected operational limit. At this extreme strained 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 strain 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.

  9. Flexible Bond Wire Capacitive Strain Sensor for Vehicle Tyres.

    PubMed

    Cao, Siyang; Pyatt, Simon; Anthony, Carl J; Kubba, Ammar I; Kubba, Ali E; Olatunbosun, Oluremi

    2016-06-21

    The safety of the driving experience and manoeuvrability of a vehicle can be improved by detecting the strain in tyres. To measure strain accurately in rubber, the strain sensor needs to be flexible so that it does not deform the medium that it is measuring. In this work, a novel flexible bond wire capacitive strain sensor for measuring the strain in tyres is developed, fabricated and calibrated. An array of 25 micron diameter wire bonds in an approximately 8 mm × 8 mm area is built to create an interdigitated structure, which consists of 50 wire loops resulting in 49 capacitor pairs in parallel. Laser machining was used to pattern copper on a flexible printed circuit board PCB to make the bond pads for the wire attachment. The wire array was finally packaged and embedded in polydimethylsiloxane (PDMS), which acts as the structural material that is strained. The capacitance of the device is in a linear like relationship with respect to the strain, which can measure the strain up to at least ±60,000 micro-strain (±6%) with a resolution of ~132 micro-strain (0.013%). In-tyre testing under static loading has shown the ability of the sensor to measure large tyre strains. The technology used for sensor fabrication lends itself to mass production and so the design is considered to be consistent with low cost commercialisable strain sensing technology.

  10. Flexible Bond Wire Capacitive Strain Sensor for Vehicle Tyres

    PubMed Central

    Cao, Siyang; Pyatt, Simon; Anthony, Carl J.; Kubba, Ammar I.; Kubba, Ali E.; Olatunbosun, Oluremi

    2016-01-01

    The safety of the driving experience and manoeuvrability of a vehicle can be improved by detecting the strain in tyres. To measure strain accurately in rubber, the strain sensor needs to be flexible so that it does not deform the medium that it is measuring. In this work, a novel flexible bond wire capacitive strain sensor for measuring the strain in tyres is developed, fabricated and calibrated. An array of 25 micron diameter wire bonds in an approximately 8 mm × 8 mm area is built to create an interdigitated structure, which consists of 50 wire loops resulting in 49 capacitor pairs in parallel. Laser machining was used to pattern copper on a flexible printed circuit board PCB to make the bond pads for the wire attachment. The wire array was finally packaged and embedded in polydimethylsiloxane (PDMS), which acts as the structural material that is strained. The capacitance of the device is in a linear like relationship with respect to the strain, which can measure the strain up to at least ±60,000 micro-strain (±6%) with a resolution of ~132 micro-strain (0.013%). In-tyre testing under static loading has shown the ability of the sensor to measure large tyre strains. The technology used for sensor fabrication lends itself to mass production and so the design is considered to be consistent with low cost commercialisable strain sensing technology. PMID:27338402

  11. High temperature static strain measurement with an electrical resistance strain gage

    NASA Technical Reports Server (NTRS)

    Lei, Jih-Fen

    1992-01-01

    An electrical resistance strain gage that can supply accurate static strain 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.

  12. The genome of Shigella dysenteriae strain Sd1617 comparison to representative strains in evaluating pathogenesis

    PubMed Central

    Vongsawan, Ajchara A.; Kapatral, Vinayak; Vaisvil, Benjamin; Burd, Henry; Serichantalergs, Oralak; Venkatesan, Malabi M.; Mason, Carl J.

    2015-01-01

    We sequenced and analyzed Shigella dysenteriae strain Sd1617 serotype 1 that is widely used as model strain 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

  13. Strain Engineering to Modify the Electrochemistry of Energy Storage Electrodes

    NASA Astrophysics Data System (ADS)

    Muralidharan, Nitin; Carter, Rachel; Oakes, Landon; Cohn, Adam P.; Pint, Cary L.

    2016-06-01

    Strain engineering has been a critical aspect of device design in semiconductor manufacturing for the past decade, but remains relatively unexplored for other applications, such as energy storage. Using mechanical strain as an input parameter to modulate electrochemical potentials of metal oxides opens new opportunities intersecting fields of electrochemistry and mechanics. Here we demonstrate that less than 0.1% strain on a Ni-Ti-O based metal-oxide formed on superelastic shape memory NiTi alloys leads to anodic and cathodic peak potential shifts by up to ~30 mV in an electrochemical cell. Moreover, using the superelastic properties of NiTi to enable strain recovery also recovers the electrochemical potential of the metal oxide, providing mechanistic evidence of strain-modified electrochemistry. These results indicate that mechanical energy can be coupled with electrochemical systems to efficiently design and optimize a new class of strain-modulated energy storage materials.

  14. Ultra-responsive soft matter from strain-stiffening hydrogels

    NASA Astrophysics Data System (ADS)

    Jaspers, Maarten; Dennison, Matthew; Mabesoone, Mathijs F. J.; Mackintosh, Frederick C.; Rowan, Alan E.; Kouwer, Paul H. J.

    2014-12-01

    The stiffness of hydrogels is crucial for their application. Nature’s hydrogels become stiffer as they are strained. This stiffness is not constant but increases when the gel is strained. This stiffening is used, for instance, by cells that actively strain their environment to modulate their function. When optimized, such strain-stiffening materials become extremely sensitive and very responsive to stress. Strain stiffening, however, is unexplored in synthetic gels since the structural design parameters are unknown. Here we uncover how readily tuneable parameters such as concentration, temperature and polymer length impact the stiffening behaviour. Our work also reveals the marginal point, a well-described but never observed, critical point in the gelation process. Around this point, we observe a transition from a low-viscous liquid to an elastic gel upon applying minute stresses. Our experimental work in combination with network theory yields universal design principles for future strain-stiffening materials.

  15. Strain Engineering to Modify the Electrochemistry of Energy Storage Electrodes

    PubMed Central

    Muralidharan, Nitin; Carter, Rachel; Oakes, Landon; Cohn, Adam P.; Pint, Cary L.

    2016-01-01

    Strain engineering has been a critical aspect of device design in semiconductor manufacturing for the past decade, but remains relatively unexplored for other applications, such as energy storage. Using mechanical strain as an input parameter to modulate electrochemical potentials of metal oxides opens new opportunities intersecting fields of electrochemistry and mechanics. Here we demonstrate that less than 0.1% strain on a Ni-Ti-O based metal-oxide formed on superelastic shape memory NiTi alloys leads to anodic and cathodic peak potential shifts by up to ~30 mV in an electrochemical cell. Moreover, using the superelastic properties of NiTi to enable strain recovery also recovers the electrochemical potential of the metal oxide, providing mechanistic evidence of strain-modified electrochemistry. These results indicate that mechanical energy can be coupled with electrochemical systems to efficiently design and optimize a new class of strain-modulated energy storage materials. PMID:27283872

  16. Ultra-responsive soft matter from strain-stiffening hydrogels

    PubMed Central

    Jaspers, Maarten; Dennison, Matthew; Mabesoone, Mathijs F. J.; MacKintosh, Frederick C.; Rowan, Alan E.; Kouwer, Paul H. J.

    2014-01-01

    The stiffness of hydrogels is crucial for their application. Nature’s hydrogels become stiffer as they are strained. This stiffness is not constant but increases when the gel is strained. This stiffening is used, for instance, by cells that actively strain their environment to modulate their function. When optimized, such strain-stiffening materials become extremely sensitive and very responsive to stress. Strain stiffening, however, is unexplored in synthetic gels since the structural design parameters are unknown. Here we uncover how readily tuneable parameters such as concentration, temperature and polymer length impact the stiffening behaviour. Our work also reveals the marginal point, a well-described but never observed, critical point in the gelation process. Around this point, we observe a transition from a low-viscous liquid to an elastic gel upon applying minute stresses. Our experimental work in combination with network theory yields universal design principles for future strain-stiffening materials. PMID:25510333

  17. Ultra-responsive soft matter from strain-stiffening hydrogels.

    PubMed

    Jaspers, Maarten; Dennison, Matthew; Mabesoone, Mathijs F J; MacKintosh, Frederick C; Rowan, Alan E; Kouwer, Paul H J

    2014-12-16

    The stiffness of hydrogels is crucial for their application. Nature's hydrogels become stiffer as they are strained. This stiffness is not constant but increases when the gel is strained. This stiffening is used, for instance, by cells that actively strain their environment to modulate their function. When optimized, such strain-stiffening materials become extremely sensitive and very responsive to stress. Strain stiffening, however, is unexplored in synthetic gels since the structural design parameters are unknown. Here we uncover how readily tuneable parameters such as concentration, temperature and polymer length impact the stiffening behaviour. Our work also reveals the marginal point, a well-described but never observed, critical point in the gelation process. Around this point, we observe a transition from a low-viscous liquid to an elastic gel upon applying minute stresses. Our experimental work in combination with network theory yields universal design principles for future strain-stiffening materials.

  18. Characterization of Burkholderia pseudomallei and Burkholderia pseudomallei-like strains.

    PubMed Central

    Brett, P. J.; Deshazer, D.; Woods, D. E.

    1997-01-01

    Previous reports in the literature suggest that Burkholderia pseudomallei strains can be differentiated on the basis of animal virulence. Twenty environmentally and clinically derived isolates of Burkholderia pseudomallei were examined for the production of exoenzymes, morphological and biochemical phenotypes and virulence for Syrian golden hamsters. The partial sequence of the 16S ribosomal RNA [rRNA] genes from a number of these strains was also determined. Based upon these observations, it is suggested that highly virulent Burkholderia pseudomallei strains are true Burkholderia pseudomallei strains. The DNA sequences of the 16S rRNA genes of the true Burkholderia pseudomallei strains were identical to the published sequences for Burkholderia pseudomallei while differences were revealed between the published sequences and those of the lowly virulent strains. Thus, these latter strains have been designated as Burkholderia pseudomallei-like organisms since they demonstrate significant differences in exoenzyme production, hamster virulence and 16S rRNA gene sequences. PMID:9129590

  19. Genome Sequence of Human Rhinovirus A22, Strain Lancaster/2015

    PubMed Central

    Atkinson, Kate V.; Bishop, Lisa A.; Rhodes, Glenn; Salez, Nicolas; McEwan, Neil R.; Hegarty, Matthew J.; Robey, Julie; Harding, Nicola; Wetherell, Simon; Lauder, Robert M.; Pickup, Roger W.; Wilkinson, Mark

    2017-01-01

    ABSTRACT The genome of human rhinovirus A22 (HRV-A22) was assembled by deep sequencing RNA samples from nasopharyngeal swabs. The assembled genome is 8.7% divergent from the HRV-A22 reference strain over its full length, and it is only the second full-length genome sequence for HRV-A22. The new strain is designated strain HRV-A22/Lancaster/2015. PMID:28336607

  20. Design and evaluation of two-stage multiplex real-time PCR method for detecting O157:H7 and non-O157 STEC strains from beef samples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction: E. coli O157:H7 was first recognized as a human pathogen in 1982 and until recently was the only E. coli strain mandated for testing by the USDA. In June 2012, the USDA declared six additional Shiga-toxin producing E. coli serogroups (O26, O45, O103, O111, O121, and O145) as adulterant...

  1. The designated type strain of Pseudomonas halophila Fendrich 1989 is DSM 3051, the designated type strain of Halovibrio variabilis Fendrich 1989 is DSM 3050, the new name Halomonas utahensis (Fendrich 1989) Sorokin and Tindall 2006 is created for the species represented by DSM 3051 when treated as a member of the genus Halomonas, the combination Halomonas variabilis (Fendrich 1989) Dobson and Franzmann 1996 is rejected, and the combination Halovibrio denitrificans Sorokin et al. 2006 is validly published with an emendation of the description of the genus Halovibrio Fendrich 1989 emend. Sorokin et al. 2006. Opinion 93. 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 designated type strain of Pseudomonas halophila Fendrich 1989 is DSM 3051 (replacing DSM 3050) and the designated type strain of Halovibrio variabilis Fendrich 1989 is DSM 3050 (replacing DSM 3051). A new name, Halomonas utahensis (Fendrich 1989) Sorokin and Tindall 2006 nom. nov., is created for the species represented by DSM 3051 when treated as a member of the genus Halomonas, because the combination Halomonas halophila (Quesada et al. 1984) Dobson and Franzmann 1996 has priority based on the fact that the epithet halophila in the combination Halomonas halophila (Quesada et al. 1984) Dobson and Franzmann 1996 ( BASOYNM: Deleya halophila Quesada et al. 1984) has priority over the epithet halophila should the taxon Pseudomonas halophila Fendrich 1989 be treated as a member of the genus Halomonas. The combination Halomonas variabilis (Fendrich 1989) Dobson and Franzmann 1996 is rejected. The combination Halovibrio denitrificans Sorokin et al. 2006 is validly published with an emendation of the description of the genus Halovibrio Fendrich 1989 emend. Sorokin et al. 2006.

  2. 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.

  3. 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.

  4. High-Temperature Adhesive Strain Gage Developed

    NASA Technical Reports Server (NTRS)

    Pereira, J. Michael; Roberts, Gary D.

    1997-01-01

    Researchers at the NASA Lewis Research Center have developed a unique strain 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 strain gages and adhesives. For example, typical commercial strain 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 strain 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' strain 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 strain 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 strain gage specifications at 315 C. An example of the performance characteristics of the gage can be seen in the figure, which compares the strain gage measurement on a polyimide specimen at 315 C with an extensometer measurement.

  5. Draft Genome Sequence of Tannerella forsythia Type Strain ATCC 43037.

    PubMed

    Friedrich, Valentin; Pabinger, Stephan; Chen, Tsute; Messner, Paul; Dewhirst, Floyd E; Schäffer, Christina

    2015-06-11

    Tannerella forsythia is an oral pathogen implicated in the development of periodontitis. Here, we report the draft genome sequence of the Tannerella forsythia strain ATCC 43037. The previously available genome of this designation (NCBI reference sequence NC_016610.1) was discovered to be derived from a different strain, FDC 92A2 (= ATCC BAA-2717).

  6. Strain- and Temperature-Dependence of Electromagnetic Metamaterials

    DTIC Science & Technology

    2012-08-01

    Analytic Expressions are powerful tools for describing metamaterial strain/temp- dependence : - Provide insight into physics behind linkage; - Enable...strain/temp- dependence for unit cells in same design family. Analytic Expressions enable efficient determination of EM(Electromagnetic) performance of

  7. 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.

  8. Muscle strain injuries.

    PubMed

    Garrett, W E

    1996-01-01

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

  9. Development of a Strain-Specific Molecular Method for Quantitating Individual Campylobacter Strains in Mixed Populations▿

    PubMed Central

    Elvers, Karen T.; Helps, Christopher R.; Wassenaar, Trudy M.; Allen, Vivien M.; Newell, Diane G.

    2008-01-01

    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 strain- and genus-specific oligonucleotide probes, was developed to detect and enumerate specific campylobacter strains in mixed populations. Strain-specific oligonucleotide probes were designed for the short variable regions (SVR) of the flaA gene in individual Campylobacter jejuni strains. 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 strains with closely related SVR sequences and mixtures of these strains. Colony lifts of campylobacters were hybridized sequentially with up to two labeled strain-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 strain 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 strains isolated from poultry transport crate wash tank water. This method is quantitative, sensitive, and highly specific and allows the identification and enumeration of selected strains among all of the campylobacters in environmental samples. PMID:18281428

  10. Development of high temperature strain gages

    NASA Technical Reports Server (NTRS)

    Lemcoe, M. M.

    1973-01-01

    High temperature electric resistance wire strain gages were developed and evaluated for use at temperatures exceeding 922 K (1200 F). A special high temperature strain 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.

  11. Atmospheric corrosion sensor based on strain measurement

    NASA Astrophysics Data System (ADS)

    Kasai, Naoya; Hiroki, Masatoshi; Yamada, Toshirou; Kihira, Hiroshi; Matsuoka, Kazumi; Kuriyama, Yukihisa; Okazaki, Shinji

    2017-01-01

    In this paper, an in situ atmospheric corrosion sensor based on strain 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 strain 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.

  12. A new report of Nocardiopsis valliformis strain OT1 from alkaline Lonar crater of India and its use in synthesis of silver nanoparticles with special reference to evaluation of antibacterial activity and cytotoxicity.

    PubMed

    Rathod, Dnyaneshwar; Golinska, Patrycja; Wypij, Magdalena; Dahm, Hanna; Rai, Mahendra

    2016-10-01

    The authors report the biological synthesis of silver nanoparticles (AgNPs) by alkaliphilic actinobacterium Nocardiopsis valliformis OT1 strain isolated for the first time from Lonar crater, India. The primary detection of silver NPs formation was made by colour change from colourless to dark brown and confirmed by UV-Vis spectrum of AgNPs at 423 nm, specific for AgNPs. Further, AgNPs were characterized by nanoparticle tracking analysis, Zeta sizer, Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM) analyses. FTIR analysis showed the presence of proteins as capping agent. TEM analysis revealed the formation of spherical and polydispersed AgNPs within the size range of 5-50 nm. The antimicrobial activity of silver nanoparticles against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis was evaluated. The AgNPs showed the maximum antibacterial activity against B. subtilis (Gram positive) and the minimum against E. coli (Gram negative). The minimal inhibitory concentration values of AgNPs for the tested bacteria were found to be in the range of 30-80 µg/mL. The AgNPs demonstrated higher antibacterial activity against all the bacteria tested as compared with the commercially available antibiotics. The cytotoxicity of biosynthesized AgNPs against in vitro human cervical cancer cell line (HeLa) demonstrated a dose-response activity. The IC50 value was found to be 100 µg/mL of AgNPs against cancer HeLa cell line.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. A strain device imposing dynamic and uniform equi-biaxial strain to cultured cells.

    PubMed

    Sotoudeh, M; Jalali, S; Usami, S; Shyy, J Y; Chien, S

    1998-01-01

    The objective of this study is to design a new apparatus to allow the control of the magnitude and frequency of dynamic stretch applied uniformly to cells cultured on a silicon elastic membrane. The apparatus is designed to produce equi-biaxial dynamic stretches with area changes ranging from 0% to 55% and frequencies ranging from 0 to 2 Hz. Homogeneous finite strain analysis using triangles of markers was performed to compute the symmetric two-dimensional Lagrangian strain tensor on the membrane. Measurements of strain in both static and dynamic conditions showed that the shear component of the strain tensor (Erc) was near zero, and that there was no significant difference between radial (Err) and circumferential (Ecc) components, indicating the attainment of equi-biaxial strain. Bovine aortic endothelial cells were transiently transfected with a chimeric construct in which the luciferase reporter is driven by TPA-responsive elements (TRE). The transfected cells cultured on the membrane were stretched. The luciferase activity increased significantly only when the cells were stretched by 15% or more in area. Cells in different locations of the membrane showed similar induction of luciferase activities, confirming that strain is uniform and equi-biaxial across the membrane.

  19. Forming blocks speed production of strain gage grids

    NASA Technical Reports Server (NTRS)

    Bonn, J. L.; Gardner, D. E.

    1965-01-01

    A tool is designed which facilitates the forming of wire grids used in manufacturing strain gage grids. Flattening the grid wire by a cold working process produces a stabilized grid which can be readily handled for storage or shipment.

  20. Development of a fiber optic high temperature strain sensor

    NASA Technical Reports Server (NTRS)

    Rausch, E. O.; Murphy, K. E.; Brookshire, S. P.

    1992-01-01

    From 1 Apr. 1991 to 31 Aug. 1992, the Georgia Tech Research Institute conducted a research program to develop a high temperature fiber optic strain sensor as part of a measurement program for the space shuttle booster rocket motor. The major objectives of this program were divided into four tasks. Under Task 1, the literature on high-temperature fiber optic strain sensors was reviewed. Task 2 addressed the design and fabrication of the strain sensor. Tests and calibration were conducted under Task 3, and Task 4 was to generate recommendations for a follow-on study of a distributed strain sensor. Task 4 was submitted to NASA as a separate proposal.

  1. Strain phase separation: Formation of ferroelastic domain structures

    NASA Astrophysics Data System (ADS)

    Xue, Fei; Li, Yongjun; Gu, Yijia; Zhang, Jinxing; Chen, Long-Qing

    2016-12-01

    Phase decomposition is a well-known process leading to the formation of two-phase mixtures. Here we show that a strain imposed on a ferroelastic crystal promotes the formation of mixed phases and domains, i.e., strain phase separation with local strains determined by a common tangent construction on the free energy versus strain curves. It is demonstrated that a domain structure can be understood using the concepts of domain/phase rule, lever rule, and coherent and incoherent strain phase separation, in a complete analogy to phase decomposition. The proposed strain phase separation model is validated using phase-field simulations and experimental observations of PbTi O3 and BiFe O3 thin films as examples. The proposed model provides a simple tool to guide and design domain structures of ferroelastic systems.

  2. 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

  3. 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.

  4. Identification of Strain-Specific Sequences That Distinguish a Mycoplasma gallisepticum Vaccine Strain from Field Isolates

    PubMed Central

    Ricketts, Camir; Pickler, Larissa; Maurer, John; Ayyampalayam, Saravanaraj; García, Maricarmen

    2016-01-01

    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 strains are generally difficult to distinguish from natural field isolates. In order to identify genome differences among vaccine revertants, vaccine strains, and field isolates, whole-genome sequencing of the M. gallisepticum vaccine strain ts-11 and several “ts-11-like” strains 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 strain 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 strain. PCR protocols were designed to target 5 sequences unique to the M. gallisepticum ts-11 strain: 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 strain from field isolates. This method will further supplement current approaches to quickly distinguish M. gallisepticum vaccine strains from field isolates. PMID:27847370

  5. Silicon Germanium Strained Layers and Heterostructures

    NASA Astrophysics Data System (ADS)

    Willander, M.; Nur, O.; Jain, S. C.

    2004-01-01

    The integration of strained-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 strained-Si1 xGex based optical devices into standard Silicon technology. The impact of integrating strained 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 strain 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 strained-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 strained 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 strained-Si1 xGex highly doped base have lead to optimize the performance of the bipolar technology for many applications easily. The strategies of design

  6. Strain diversity and phage resistance in complex dairy starter cultures.

    PubMed

    Spus, M; Li, M; Alexeeva, S; Wolkers-Rooijackers, J C M; Zwietering, M H; Abee, T; Smid, E J

    2015-08-01

    The compositional stability of the complex Gouda cheese starter culture Ur is thought to be influenced by diversity in phage resistance of highly related strains that co-exist together with bacteriophages. To analyze the role of bacteriophages in maintaining culture diversity at the level of genetic lineages, simple blends of Lactococcus lactis strains were made and subsequently propagated for 152 generations in the absence and presence of selected bacteriophages. We first screened 102 single-colony isolates (strains) from the complex cheese starter for resistance to bacteriophages isolated from this starter. The collection of isolates represents all lactococcal genetic lineages present in the culture. Large differences were found in bacteriophage resistance among strains belonging to the same genetic lineage and among strains from different lineages. The blends of strains were designed such that 3 genetic lineages were represented by strains with different levels of phage resistance. The relative abundance of the lineages in blends with phages was not stable throughout propagation, leading to continuous changes in composition up to 152 generations. The individual resistance of strains to phage predation was confirmed as one of the factors influencing starter culture diversity. Furthermore, loss of proteolytic activity of initially proteolytic strains was found. Reconstituted blends with only 4 strains with a variable degree of phage resistance showed complex behavior during prolonged propagation.

  7. Brittle superconducting magnets: an equivilent strain model

    SciTech Connect

    Barzi, E.; Danuso, M.

    2010-08-01

    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 strain 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 strain 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 strain 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 strain 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 strain model.

  8. 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.

  9. 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.

  10. 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

  11. 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

  12. Quality Control On Strained Semiconductor Devices

    SciTech Connect

    Dommann, Alex; Neels, Antonia

    2010-11-24

    New semiconductor devices are based very often on strained silicon which promises to squeeze more device performance out of current devices. With strained silicon it is possible to get the same device performance using less power. The technique is using strain 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 strain 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.

  13. The Complete Nucleotide Sequence of the Carbapenem Resistance-Conferring Conjugative Plasmid pLD209 from a Pseudomonas putida Clinical Strain Reveals a Chimeric Design Formed by Modules Derived from Both Environmental and Clinical Bacteria

    PubMed Central

    Marchiaro, Patricia M.; Brambilla, Luciano; Morán-Barrio, Jorgelina; Revale, Santiago; Pasteran, Fernando; Vila, Alejandro J.; Viale, Alejandro M.

    2014-01-01

    The complete sequence of the carbapenem-resistance-conferring conjugative plasmid pLD209 from a Pseudomonas putida clinical strain is presented. pLD209 is formed by 3 well-defined regions: an adaptability module encompassing a Tn402-like class 1 integron of clinical origin containing blaVIM-2 and aacA4 gene cassettes, partitioning and transfer modules, and a replication module derived from plasmids of environmental bacteria. pLD209 is thus a mosaic of modules originating in both the clinical and environmental (nonclinical) microbiota. PMID:24395220

  14. 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 ...

  15. Retaining large and adjustable elastic strains of kilogram-scale Nb nanowires [Better Superconductor by Elastic Strain Engineering: Kilogram-scale Free-Standing Niobium Metal Composite with Large Retained Elastic Strains

    SciTech Connect

    Hao, Shijie; Cui, Lishan; Wang, Hua; Jiang, Daqiang; Liu, Yinong; Yan, Jiaqiang; Ren, Yang; Han, Xiaodong; Brown, Dennis E.; Li, Ju

    2016-02-10

    Crystals held at ultrahigh elastic strains and stresses may exhibit exceptional physical and chemical properties. Individual metallic nanowires can sustain ultra-large elastic strains of 4-7%. However, retaining elastic strains of such magnitude in kilogram-scale nanowires is challenging. Here, we find that under active load, ~5.6% elastic strain can be achieved in Nb nanowires in a composite material. Moreover, large tensile (2.8%) and compressive (-2.4%) elastic strains can be retained in kilogram-scale Nb nanowires when the composite is unloaded to a free-standing condition. It is then demonstrated that the retained tensile elastic strains of Nb nanowires significantly increase their superconducting transition temperature and critical magnetic fields, corroborating ab initio calculations based on BCS theory. This free-standing nanocomposite design paradigm opens new avenues for retaining ultra-large elastic strains in great quantities of nanowires and elastic-strain-engineering at industrial scale.

  16. Transient dynamic distributed strain sensing using photonic crystal fibres

    NASA Astrophysics Data System (ADS)

    Samad, Shafeek A.; Hegde, G. M.; Roy Mahapatra, D.; Hanagud, S.

    2014-02-01

    A technique to determine the strain field in one-dimensional (1D) photonic crystal (PC) involving high strain rate, high temperature around shock or ballistic impact is proposed. Transient strain sensing is important in aerospace and other structural health monitoring (SHM) applications. We consider a MEMS based smart sensor design with photonic crystal integrated on a silicon substrate for dynamic strain correlation. Deeply etched silicon rib waveguides with distributed Bragg reflectors are suitable candidates for miniaturization of sensing elements, replacing the conventional FBG. Main objective here is to investigate the effect of non-uniform strain localization on the sensor output. Computational analysis is done to determine the static and dynamic strain sensing characteristics of the 1D photonic crystal based sensor. The structure is designed and modeled using Finite Element Method. Dynamic localization of strain field is observed. The distributed strain field is used to calculated the PC waveguide response. The sensitivity of the proposed sensor is estimated to be 0.6 pm/μɛ.

  17. 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.

  18. Unexpected strain-stiffening in crystalline solids.

    PubMed

    Jiang, Chao; Srinivasan, Srivilliputhur G

    2013-04-18

    Strain-stiffening--an increase in material stiffness at large strains--is a vital mechanism by which many soft biological materials thwart excessive deformation to protect tissue integrity. Understanding the fundamental science of strain-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 strain-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 strain-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.

  19. High catalase production by Rhizobium radiobacter strain 2-1.

    PubMed

    Nakayama, Mami; Nakajima-Kambe, Toshiaki; Katayama, Hideki; Higuchi, Kazuhiko; Kawasaki, Yoshio; Fuji, Ryujiro

    2008-12-01

    To promote the application of catalase for treating wastewater containing hydrogen peroxide, bacteria exhibiting high catalase activity were screened. A bacterium, designated strain 2-1, with high catalase activity was isolated from the wastewater of a beverage factory that uses hydrogen peroxide. Strain 2-1 was identified as Rhizobium radiobacter (formerly known as Agrobacterium tumefaciens) on the basis of both phenotypic and genotypic characterizations. Although some strains of R. radiobacter are known plant pathogens, polymerase chain reaction (PCR) analysis showed that strain 2-1 has no phytopathogenic factor. Compared with a type strain of R. radiobacter, the specific catalase activity of strain 2-1 was approximately 1000-fold. Moreover, Strain 2-1 grew faster and exhibited considerably higher catalase activity than other microorganisms that have been used for industrial catalase production. Strain 2-1 is harmless to humans and the environment and produces catalase efficiently, suggesting that strain 2-1 is a good resource for the mass production of catalase for the treatment of hydrogen peroxide-containing wastewater.

  20. Development of an Integrated Evaluation System for a Stretchable Strain Sensor

    PubMed Central

    Jeon, Hyungkook; Hong, Seong Kyung; Cho, Seong J.; Lim, Geunbae

    2016-01-01

    Recently, much research has been focused on stretchable or flexible electronic sensors for the measurement of strain or deformation on movable and variably shaped objects. In this research, to evaluate the performance of stretchable strain sensors, we have designed an integrated evaluation system capable of simultaneously measuring the change in stress and conductance of a strain sensor. Using the designed system, we have successfully evaluated the deformation characteristics, sensing range and sensing sensitivity of a stretchable strain sensor. We believe that the developed integrated evaluation system could be a useful tool for performance evaluation of stretchable strain sensors. PMID:27447639

  1. 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.

  2. 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.

  3. 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

  4. Effect of anharmonicity of interatomic potential on strain distribution in semiconductor nanostructures

    NASA Technical Reports Server (NTRS)

    Lazarenkova, Olga L.; von Allmen, Paul; Oyafuso, Fabiano; Lee, Seungwoii; Klimeck, Gerhard

    2004-01-01

    Experiments and theory have shown that the energy spectrum of nanostructures is extremely sensitive to the built-in strain. Knowledge of the strain distribution is therefore Experiments and theory have shown that the energy spectrum of nanostructures is extremely sensitive to the built-in strain. Knowledge of the strain distribution is therefore of utmost importance for the design of optical devices with prescribed light emission spectrum.

  5. Palladium-chromium static strain gage for high temperature propulsion systems

    NASA Technical Reports Server (NTRS)

    Lei, Jih-Fen

    1991-01-01

    The present electrical strain gage for high temperature static strain measurements is in its fine-wire and thin-film forms designed to be temperature-compensated on any substrate material. The gage element is of Pd-Cr alloy, while the compensator is of Pt. Because the thermally-induced apparent strain of this compensated wire strain gage is sufficiently small, with good reproducibility between thermal cycles to 800 C, output figures can be corrected within a reasonable margin of error.

  6. Strain engineering of nanowire multi-quantum well demonstrated by Raman spectroscopy.

    PubMed

    Wölz, Martin; Ramsteiner, Manfred; Kaganer, Vladimir M; Brandt, Oliver; Geelhaar, Lutz; Riechert, Henning

    2013-09-11

    An analysis of the strain in an axial nanowire superlattice shows that the dominating strain state can be defined arbitrarily between unstrained and maximum mismatch strain by choosing the segment height ratios. We give experimental evidence for a successful strain design in series of GaN nanowire ensembles with axial InxGa1-xN quantum wells. We vary the barrier thickness and determine the strain state of the quantum wells by Raman spectroscopy. A detailed calculation of the strain distribution and LO phonon frequency shift shows that a uniform in-plane lattice constant in the nanowire segments satisfactorily describes the resonant Raman spectra, although in reality the three-dimensional strain profile at the periphery of the quantum wells is complex. Our strain analysis is applicable beyond the InxGa1-xN/GaN system under study, and we derive universal rules for strain engineering in nanowire heterostructures.

  7. Electronic Raman scattering as an ultra-sensitive probe of strain effects in semiconductors

    PubMed Central

    Fluegel, Brian; Mialitsin, Aleksej V.; Beaton, Daniel A.; Reno, John L.; Mascarenhas, Angelo

    2015-01-01

    Semiconductor strain engineering has become a critical feature of high-performance electronics because of the significant device performance enhancements that it enables. These improvements, which emerge from strain-induced modifications to the electronic band structure, necessitate new ultra-sensitive tools to probe the strain in semiconductors. Here, we demonstrate that minute amounts of strain in thin semiconductor epilayers can be measured using electronic Raman scattering. We applied this strain measurement technique to two different semiconductor alloy systems using coherently strained epitaxial thin films specifically designed to produce lattice-mismatch strains as small as 10−4. Comparing our strain sensitivity and signal strength in AlxGa1−xAs with those obtained using the industry-standard technique of phonon Raman scattering, we found that there was a sensitivity improvement of 200-fold and a signal enhancement of 4 × 103, thus obviating key constraints in semiconductor strain metrology. PMID:26017853

  8. Electronic Raman scattering as an ultra-sensitive probe of strain effects in semiconductors

    DOE PAGES

    Fluegel., Brian; Mialitsin, Aleksej V.; Beaton, Daniel A.; ...

    2015-05-28

    Semiconductor strain engineering has become a critical feature of high-performance electronics because of the significant device performance enhancements that it enables. These improvements, which emerge from strain-induced modifications to the electronic band structure, necessitate new ultra-sensitive tools to probe the strain in semiconductors. Here, we demonstrate that minute amounts of strain in thin semiconductor epilayers can be measured using electronic Raman scattering. We also applied this strain measurement technique to two different semiconductor alloy systems using coherently strained epitaxial thin films specifically designed to produce lattice-mismatch strains as small as 10-4. Thus, comparing our strain sensitivity and signal strength inmore » AlxGa 1-x As with those obtained using the industry-standard technique of phonon Raman scattering, we found that there was a sensitivity improvement of 200-fold and a signal enhancement of 4 × 103, thus obviating key constraints in semiconductor strain metrology.« less

  9. High strain rate behaviour of polypropylene microfoams

    NASA Astrophysics Data System (ADS)

    Gómez-del Río, T.; Garrido, M. A.; Rodríguez, J.; Arencón, D.; Martínez, A. B.

    2012-08-01

    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 strain 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 strain rates (0.001 to 3000 s-1) in order to show the effects of the processing parameters and strain rate on the mechanical properties. High strain rate tests were performed using a Split Hopkinson Pressure Bar apparatus (SHPB). Polypropylene and polyethylene-ethylene block copolymer foams of various densities were considered.

  10. Thermal strain analysis of optic fiber sensors.

    PubMed

    Her, Shiuh-Chuan; Huang, Chih-Ying

    2013-01-31

    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 strain 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 strain induced by the host structure is transferred via the adhesive layer and protective coating. In this investigation, an analytical expression of the thermal strain and stress in the optical fiber is presented. The theoretical predictions are validated using the finite element method. Numerical results show that the thermal strain 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.

  11. Uncovering high-strain rate protection mechanism in nacre

    NASA Astrophysics Data System (ADS)

    Huang, Zaiwang; Li, Haoze; Pan, Zhiliang; Wei, Qiuming; Chao, Yuh J.; Li, Xiaodong

    2011-11-01

    Under high-strain-rate compression (strain rate ~103 s-1), nacre (mother-of-pearl) exhibits surprisingly high fracture strength vis-à-vis under quasi-static loading (strain rate 10-3 s-1). Nevertheless, the underlying mechanism responsible for such sharply different behaviors in these two loading modes remains completely unknown. Here we report a new deformation mechanism, adopted by nacre, the best-ever natural armor material, to protect itself against predatory penetrating impacts. It involves the emission of partial dislocations and the onset of deformation twinning that operate in a well-concerted manner to contribute to the increased high-strain-rate fracture strength of nacre. Our findings unveil that Mother Nature delicately uses an ingenious strain-rate-dependent stiffening mechanism with a purpose to fight against foreign attacks. These findings should serve as critical design guidelines for developing engineered body armor materials.

  12. High-Temperature Strain Sensing for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Piazza, Anthony; Richards, Lance W.; Hudson, Larry D.

    2008-01-01

    Thermal protection systems (TPS) and hot structures are utilizing advanced materials that operate at temperatures that exceed abilities to measure structural performance. Robust strain sensors that operate accurately and reliably beyond 1800 F are needed but do not exist. These shortcomings hinder the ability to validate analysis and modeling techniques and hinders the ability to optimize structural designs. This presentation examines high-temperature strain sensing for aerospace applications and, more specifically, seeks to provide strain data for validating finite element models and thermal-structural analyses. Efforts have been made to develop sensor attachment techniques for relevant structural materials at the small test specimen level and to perform laboratory tests to characterize sensor and generate corrections to apply to indicated strains. Areas highlighted in this presentation include sensors, sensor attachment techniques, laboratory evaluation/characterization of strain measurement, and sensor use in large-scale structures.

  13. Uncovering high-strain rate protection mechanism in nacre.

    PubMed

    Huang, Zaiwang; Li, Haoze; Pan, Zhiliang; Wei, Qiuming; Chao, Yuh J; Li, Xiaodong

    2011-01-01

    Under high-strain-rate compression (strain rate approximately 10(3) s(-1)), nacre (mother-of-pearl) exhibits surprisingly high fracture strength vis-à-vis under quasi-static loading (strain rate 10(-3) s(-1)). Nevertheless, the underlying mechanism responsible for such sharply different behaviors in these two loading modes remains completely unknown. Here we report a new deformation mechanism, adopted by nacre, the best-ever natural armor material, to protect itself against predatory penetrating impacts. It involves the emission of partial dislocations and the onset of deformation twinning that operate in a well-concerted manner to contribute to the increased high-strain-rate fracture strength of nacre. Our findings unveil that Mother Nature delicately uses an ingenious strain-rate-dependent stiffening mechanism with a purpose to fight against foreign attacks. These findings should serve as critical design guidelines for developing engineered body armor materials.

  14. Uncovering high-strain rate protection mechanism in nacre

    PubMed Central

    Huang, Zaiwang; Li, Haoze; Pan, Zhiliang; Wei, Qiuming; Chao, Yuh J.; Li, Xiaodong

    2011-01-01

    Under high-strain-rate compression (strain rate ∼103 s−1), nacre (mother-of-pearl) exhibits surprisingly high fracture strength vis-à-vis under quasi-static loading (strain rate 10−3 s−1). Nevertheless, the underlying mechanism responsible for such sharply different behaviors in these two loading modes remains completely unknown. Here we report a new deformation mechanism, adopted by nacre, the best-ever natural armor material, to protect itself against predatory penetrating impacts. It involves the emission of partial dislocations and the onset of deformation twinning that operate in a well-concerted manner to contribute to the increased high-strain-rate fracture strength of nacre. Our findings unveil that Mother Nature delicately uses an ingenious strain-rate-dependent stiffening mechanism with a purpose to fight against foreign attacks. These findings should serve as critical design guidelines for developing engineered body armor materials. PMID:22355664

  15. Optical Fiber Strain Instrumentation for High Temperature Aerospace Structural Monitoring

    NASA Technical Reports Server (NTRS)

    Wang, A.

    2002-01-01

    The objective of the program is the development and laboratory demonstration of sensors based on silica optical fibers for measurement of high temperature strain for aerospace materials evaluations. A complete fiber strain sensor system based on white-light interferometry was designed and implemented. An experiment set-up was constructed to permit testing of strain measurement up to 850 C. The strain is created by bending an alumina cantilever beam to which is the fiber sensor is attached. The strain calibration is provided by the application of known beam deflections. To ensure the high temperature operation capability of the sensor, gold-coated single-mode fiber is used. Moreover, a new method of sensor surface attachment which permits accurate sensor gage length determination is also developed. Excellent results were obtained at temperatures up to 800-850 C.

  16. onHigh-peak-power strain-compensated GaInAs/AlInAs quantum cascade lasers (λ ˜4.6 μm) based on a slightly diagonal active region design

    NASA Astrophysics Data System (ADS)

    Yang, Q.; Lösch, R.; Bronner, W.; Hugger, S.; Fuchs, F.; Aidam, R.; Wagner, J.

    2008-12-01

    Employing a "slightly diagonal" active region design for the quantum cascade lasers compared to a reference sample based on the conventional vertical transition design [R. Köhler et al., Appl. Phys. Lett. 76, 1092 (2000)], we have improved the maximum operation temperature, room-temperature maximum peak power per facet, and room-temperature slope efficiency from 320 K, 200 mW, and 570 mW/A to higher than 360 K, 3.2 W, and 2200 mW/A, respectively, for the device size of 16 μm×3 mm with as-cleaved facets operated in pulsed mode.

  17. Scaffold metamaterial and its application as strain sensor

    SciTech Connect

    Wu, Wei; Ren, Mengxin Pi, Biao; Cai, Wei Xu, Jingjun; Wu, Yang

    2015-08-31

    In this paper, strain sensors based on planar scaffold metamaterial design are demonstrated. The optical properties of such metamaterials are studied, which are proved to be highly dependent on the deformation of the structure. Fabricating such metamaterial on compliant polymeric substrate, the geometric parameters could be tuned with external strain and hence are found to control the reflection resonance condition of the metamaterial. Such mechanical tunability provides the opportunity to realize efficient strain sensors and about 27 nm resonance wavelength shift is observed by applying as much as 37% tensile strain. Furthermore, distinct from most of the previous works, our structures are based on “intaglio” design, which could be manufactured directly by one step fabrication using focused ion beam cutting, hence makes the fabrication process much simpler.

  18. 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.

  19. Strains and stressors: an analysis of touchscreen learning in genetically diverse mouse strains.

    PubMed

    Graybeal, Carolyn; Bachu, Munisa; Mozhui, Khyobeni; Saksida, Lisa M; Bussey, Timothy J; Sagalyn, Erica; Williams, Robert W; Holmes, Andrew

    2014-01-01

    Touchscreen-based systems are growing in popularity as a tractable, translational approach for studying learning and cognition in rodents. However, while mouse strains are well known to differ in learning across various settings, performance variation between strains in touchscreen learning has not been well described. The selection of appropriate genetic strains and backgrounds is critical to the design of touchscreen-based studies and provides a basis for elucidating genetic factors moderating behavior. Here we provide a quantitative foundation for visual discrimination and reversal learning using touchscreen assays across a total of 35 genotypes. We found significant differences in operant performance and learning, including faster reversal learning in DBA/2J compared to C57BL/6J mice. We then assessed DBA/2J and C57BL/6J for differential sensitivity to an environmental insult by testing for alterations in reversal learning following exposure to repeated swim stress. Stress facilitated reversal learning (selectively during the late stage of reversal) in C57BL/6J, but did not affect learning in DBA/2J. To dissect genetic factors underlying these differences, we phenotyped a family of 27 BXD strains generated by crossing C57BL/6J and DBA/2J. There was marked variation in discrimination, reversal and extinction learning across the BXD strains, suggesting this task may be useful for identifying underlying genetic differences. Moreover, different measures of touchscreen learning were only modestly correlated in the BXD strains, indicating that these processes are comparatively independent at both genetic and phenotypic levels. Finally, we examined the behavioral structure of learning via principal component analysis of the current data, plus an archival dataset, totaling 765 mice. This revealed 5 independent factors suggestive of "reversal learning," "motivation-related late reversal learning," "discrimination learning," "speed to respond," and "motivation during

  20. Progress Report on Alloy 617 Isochronous Stress-Strain Curves

    SciTech Connect

    Jill K. Wright; Richard N. Wright; Nancy J. Lybeck

    2014-03-01

    Isochronous stress-strain curves for Alloy 617 up to a temperature of 1000°C will be required to qualify the material for elevated temperature design in Section III, Division 1, Subsection NH of the ASME Boiler and Pressure Vessel Code. Several potential methods for developing these curves are reviewed in this report. It is shown that in general power-law creep is the rate controlling deformation mechanism for a wide range of alloy heats, test temperatures and stresses. Measurement of the strain rate sensitivity of Alloy 617 indicates that the material is highly strain rate sensitive in the tensile deformation range above about 750°C. This suggests that the concept of a hot tensile curve as a bounding case on the isochronous stress-strain diagrams is problematic. The impact of strain rate on the hot tensile curves is examined and it is concluded that incorporating such a curve is only meaningful if a single tensile strain rate (typically the ASTM standard rate of 0.5%/min) is arbitrarily defined. Current experimentally determined creep data are compared to isochronous stress-strain curves proposed previously by the German programs in the 1980s and by the 1990 draft ASME Code Case. Variability in how well the experimental data are represented by the proposed design curves that suggests further analysis is necessary prior to completing a new draft Code Case.

  1. 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.

  2. Compressive strain measurement using RFID patch antenna sensors

    NASA Astrophysics Data System (ADS)

    Cho, Chunhee; Yi, Xiaohua; Wang, Yang; Tentzeris, Manos M.; Leon, Roberto T.

    2014-04-01

    In this research, two radiofrequency identification (RFID) antenna sensor designs are tested for compressive strain measurement. The first design is a passive (battery-free) folded patch antenna sensor with a planar dimension of 61mm × 69mm. The second design is a slotted patch antenna sensor, whose dimension is reduced to 48mm × 44mm by introducing slots on antenna conducting layer to detour surface current path. A three-point bending setup is fabricated to apply compression on a tapered aluminum specimen mounted with an antenna sensor. Mechanics-electromagnetics coupled simulation shows that the antenna resonance frequency shifts when each antenna sensor is under compressive strain. Extensive compression tests are conducted to verify the strain sensing performance of the two sensors. Experimental results confirm that the resonance frequency of each antenna sensor increases in an approximately linear relationship with respect to compressive strain. The compressive strain sensing performance of the two RFID antenna sensors, including strain sensitivity and determination coefficient, is evaluated based on the experimental data.

  3. Motion Driven by Strain Gradient Fields

    PubMed Central

    Wang, Chao; Chen, Shaohua

    2015-01-01

    A new driving mechanism for direction-controlled motion of nano-scale objects is proposed, based on a model of stretching a graphene strip linked to a rigid base with linear springs of identical stiffness. We find that the potential energy difference induced by the strain gradient field in the graphene strip substrate can generate sufficient force to overcome the static and kinetic friction forces between the nano-flake and the strip substrate, resulting in the nanoscale flake motion in the direction of gradient reduction. The dynamics of the nano-flake can be manipulated by tuning the stiffness of linear springs, stretching velocity and the flake size. This fundamental law of directional motion induced by strain gradient could be very useful for promising designs of nanoscale manipulation, transportation and smart surfaces. PMID:26323603

  4. Strain monitoring of a composite wing

    NASA Astrophysics Data System (ADS)

    Strathman, Joseph; Watkins, Steve E.; Kaur, Amardeep; Macke, David C.

    2016-04-01

    An instrumented composite wing is described. The wing is designed to meet the load and ruggedness requirements for a fixed-wing unmanned aerial vehicle (UAV) in search-and-rescue applications. The UAV supports educational systems development and has a 2.1-m wingspan. The wing structure consists of a foam core covered by a carbon-fiber, laminate composite shell. To quantify the wing characteristics, a fiber-optic strain sensor was surface mounted to measure distributed strain. This sensor is based on Rayleigh scattering from local index variations and it is capable of high spatial resolution. The use of the Rayleigh-scattering fiber-optic sensors for distributed measurements is discussed.

  5. Thin film strain transducer. [in-flight measurement of stress or strain in walls of high altitude balloons

    NASA Technical Reports Server (NTRS)

    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. 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.

  7. 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.

  8. Unsteady Aerodynamic Force Sensing from Measured Strain

    NASA Technical Reports Server (NTRS)

    Pak, Chan-Gi

    2016-01-01

    , velocity, and acceleration sensors. This research demonstrates the feasibility of obtaining induced drag and lift forces through the use of distributed sensor technology with measured strain data. An active induced drag control system thus can be designed using the two computed aerodynamic forces, induced drag and lift, to improve the fuel efficiency of an aircraft. Interpolation elements between structural finite element grids and the CFD grids and centroids are successfully incorporated with the unsteady aeroelastic computation scheme. The most critical technology for the success of the proposed approach is the robust on-line parameter estimator, since the least-squares curve fitting method depends heavily on aeroelastic system frequencies and damping factors.

  9. 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.

  10. 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.

  11. 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

  12. 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)

  13. 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

  14. Role of scaffold network in controlling strain and functionalities of nanocomposite films.

    PubMed

    Chen, Aiping; Hu, Jia-Mian; Lu, Ping; Yang, Tiannan; Zhang, Wenrui; Li, Leigang; Ahmed, Towfiq; Enriquez, Erik; Weigand, Marcus; Su, Qing; Wang, Haiyan; Zhu, Jian-Xin; MacManus-Driscoll, Judith L; Chen, Long-Qing; Yarotski, Dmitry; Jia, Quanxi

    2016-06-01

    Strain is a novel approach to manipulating functionalities in correlated complex oxides. However, significant epitaxial strain can only be achieved in ultrathin layers. We show that, under direct lattice matching framework, large and uniform vertical strain up to 2% can be achieved to significantly modify the magnetic anisotropy, magnetism, and magnetotransport properties in heteroepitaxial nanoscaffold films, over a few hundred nanometers in thickness. Comprehensive designing principles of large vertical strain have been proposed. Phase-field simulations not only reveal the strain distribution but also suggest that the ultimate strain is related to the vertical interfacial area and interfacial dislocation density. By changing the nanoscaffold density and dimension, the strain and the magnetic properties can be tuned. The established correlation among the vertical interface-strain-properties in nanoscaffold films can consequently be used to tune other functionalities in a broad range of complex oxide films far beyond critical thickness.

  15. Imported lassa fever in Germany: molecular characterization of a new lassa virus strain.

    PubMed

    Günther, S; Emmerich, P; Laue, T; Kühle, O; Asper, M; Jung, A; Grewing, T; ter Meulen, J; Schmitz, H

    2000-01-01

    We describe the isolation and characterization of a new Lassa virus strain imported into Germany by a traveler who had visited Ghana, Côte D'Ivoire, and Burkina Faso. This strain, designated "AV," originated from a region in West Africa where Lassa fever has not been reported. Viral S RNA isolated from the patient's serum was amplified and sequenced. A long-range reverse transcription polymerase chain reaction allowed amplification of the full-length (3.4 kb) S RNA. The coding sequences of strain AV differed from those of all known Lassa prototype strains (Josiah, Nigeria, and LP) by approximately 20%, mainly at third codon positions. Phylogenetically, strain AV appears to be most closely related to strain Josiah from Sierra Leone. Lassa viruses comprise a group of genetically highly diverse strains, which has implications for vaccine development. The new method for full-length S RNA amplification may facilitate identification and molecular analysis of new arenaviruses or arenavirus strains.

  16. 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.

  17. Pangenome and Phylogenomic Analysis of the Pathogenic Actinobacterium Rhodococcus equi

    PubMed Central

    Anastasi, Elisa; MacArthur, Iain; Scortti, Mariela; Alvarez, Sonsiray; Giguère, Steeve; Vázquez-Boland, José A.

    2016-01-01

    We report a comparative study of 29 representative genomes of the animal pathogen Rhodococcus equi. The analyses showed that R. equi is genetically homogeneous and clonal, with a large core genome accounting for ≈80% of an isolates’ gene content. An open pangenome, even distribution of accessory genes among the isolates, and absence of significant core–genome recombination, indicated that gene gain/loss is a main driver of R. equi genome evolution. Traits previously predicted to be important in R. equi physiology, virulence and niche adaptation were part of the core genome. This included the lack of a phosphoenolpyruvate:carbohydrate transport system (PTS), unique among the rhodococci except for the closely related Rhodococcus defluvii, reflecting selective PTS gene loss in the R. equi–R. defluvii sublineage. Thought to be asaccharolytic, rbsCB and glcP non-PTS sugar permease homologues were identified in the core genome and, albeit inefficiently, R. equi utilized their putative substrates, ribose and (irregularly) glucose. There was no correlation between R. equi whole-genome phylogeny and host or geographical source, with evidence of global spread of genomovars. The distribution of host-associated virulence plasmid types was consistent with the exchange of the plasmids (and corresponding host shifts) across the R. equi population, and human infection being zoonotically acquired. Phylogenomic analyses demonstrated that R. equi occupies a central position in the Rhodococcus phylogeny, not supporting the recently proposed transfer of the species to a new genus. PMID:27638249

  18. Deciphering the Genome of Polyphosphate Accumulating Actinobacterium Microlunatus phosphovorus

    PubMed Central

    Kawakoshi, Akatsuki; Nakazawa, Hidekazu; Fukada, Junji; Sasagawa, Machi; Katano, Yoko; Nakamura, Sanae; Hosoyama, Akira; Sasaki, Hiroki; Ichikawa, Natsuko; Hanada, Satoshi; Kamagata, Yoichi; Nakamura, Kazunori; Yamazaki, Shuji; Fujita, Nobuyuki

    2012-01-01

    Polyphosphate accumulating organisms (PAOs) belong mostly to Proteobacteria and Actinobacteria and are quite divergent. Under aerobic conditions, they accumulate intracellular polyphosphate (polyP), while they typically synthesize polyhydroxyalkanoates (PHAs) under anaerobic conditions. Many ecological, physiological, and genomic analyses have been performed with proteobacterial PAOs, but few with actinobacterial PAOs. In this study, the whole genome sequence of an actinobacterial PAO, Microlunatus phosphovorus NM-1T (NBRC 101784T), was determined. The number of genes for polyP metabolism was greater in M. phosphovorus than in other actinobacteria; it possesses genes for four polyP kinases (ppks), two polyP-dependent glucokinases (ppgks), and three phosphate transporters (pits). In contrast, it harbours only a single ppx gene for exopolyphosphatase, although two copies of ppx are generally present in other actinobacteria. Furthermore, M. phosphovorus lacks the phaABC genes for PHA synthesis and the actP gene encoding an acetate/H+ symporter, both of which play crucial roles in anaerobic PHA accumulation in proteobacterial PAOs. Thus, while the general features of M. phosphovorus regarding aerobic polyP accumulation are similar to those of proteobacterial PAOs, its anaerobic polyP use and PHA synthesis appear to be different. PMID:22923697

  19. Characterization of p-Hydroxycinnamate Catabolism in a Soil Actinobacterium

    PubMed Central

    Otani, Hiroshi; Lee, Young-Eun; Casabon, Israël

    2014-01-01

    p-Hydroxycinnamates, such as ferulate and p-coumarate, are components of plant cell walls and have a number of commercial applications. Rhodococcus jostii RHA1 (RHA1) catabolizes ferulate via vanillate and the β-ketoadipate pathway. Here, we used transcriptomics to identify genes in RHA1 that are upregulated during growth on ferulate versus benzoate. The upregulated genes included three transcriptional units predicted to encode the uptake and β-oxidative deacetylation of p-hydroxycinnamates: couHTL, couNOM, and couR. Neither ΔcouL mutants nor ΔcouO mutants grew on p-hydroxycinnamates, but they did grow on vanillate. Among several p-hydroxycinnamates, CouL catalyzed the thioesterification of p-coumarate and caffeate most efficiently (kcat/Km = ∼400 mM−1 s−1). p-Coumarate was also RHA1's preferred growth substrate, suggesting that CouL is a determinant of the pathway's specificity. CouL did not catalyze the activation of sinapate, in similarity to two p-coumaric acid:coenzyme A (CoA) ligases from plants, and contains the same bulged loop that helps determine substrate specificity in the plant homologues. The couO mutant accumulated 4-hydroxy-3-methoxyphenyl-β-ketopropionate in the culture supernatant when incubated with ferulate, supporting β-oxidative deacetylation. This phenotype was not complemented with a D257N variant of CouO, consistent with the predicted role of Asp257 as a metal ligand in this amidohydrolase superfamily member. These data suggest that CouO functionally replaces the β-ketothiolase and acyl-CoA thioesterase that occur in canonical β-oxidative pathways. Finally, the transcriptomics data suggest the involvement of two distinct formaldehyde detoxification pathways in vanillate catabolism and identify a eugenol catabolic pathway. The results of this study augment our understanding of the bacterial catabolism of aromatics from renewable feedstocks. PMID:25266382

  20. Characterization of p-hydroxycinnamate catabolism in a soil Actinobacterium.

    PubMed

    Otani, Hiroshi; Lee, Young-Eun; Casabon, Israël; Eltis, Lindsay D

    2014-12-01

    p-Hydroxycinnamates, such as ferulate and p-coumarate, are components of plant cell walls and have a number of commercial applications. Rhodococcus jostii RHA1 (RHA1) catabolizes ferulate via vanillate and the β-ketoadipate pathway. Here, we used transcriptomics to identify genes in RHA1 that are upregulated during growth on ferulate versus benzoate. The upregulated genes included three transcriptional units predicted to encode the uptake and β-oxidative deacetylation of p-hydroxycinnamates: couHTL, couNOM, and couR. Neither ΔcouL mutants nor ΔcouO mutants grew on p-hydroxycinnamates, but they did grow on vanillate. Among several p-hydroxycinnamates, CouL catalyzed the thioesterification of p-coumarate and caffeate most efficiently (k(cat)/K(m) = ∼ 400 mM(-1) s(-1)). p-Coumarate was also RHA1's preferred growth substrate, suggesting that CouL is a determinant of the pathway's specificity. CouL did not catalyze the activation of sinapate, in similarity to two p-coumaric acid:coenzyme A (CoA) ligases from plants, and contains the same bulged loop that helps determine substrate specificity in the plant homologues. The couO mutant accumulated 4-hydroxy-3-methoxyphenyl-β-ketopropionate in the culture supernatant when incubated with ferulate, supporting β-oxidative deacetylation. This phenotype was not complemented with a D257N variant of CouO, consistent with the predicted role of Asp257 as a metal ligand in this amidohydrolase superfamily member. These data suggest that CouO functionally replaces the β-ketothiolase and acyl-CoA thioesterase that occur in canonical β-oxidative pathways. Finally, the transcriptomics data suggest the involvement of two distinct formaldehyde detoxification pathways in vanillate catabolism and identify a eugenol catabolic pathway. The results of this study augment our understanding of the bacterial catabolism of aromatics from renewable feedstocks.

  1. 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.

  2. 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

  3. Computerized comparison of the protein compositions of Erysipelothrix rhusiopathiae and Erysipelothrix tonsillarum strains.

    PubMed

    Bernáth, S; Német, L; Tóth, K; Morovján, G

    2001-02-01

    Protein profiles of six Erysipelothrix rhusiopathiae strains, five Erysipelothrix tonsillarum strains and three Erysipelothrix strains of uncertain taxonomic position were studied by sodium dodecyl sulphate-polyactylamide gel electrophoresis (SDS-PAGE). In a computerized comparison of the protein patterns of the strains, the level of similarity between the strains was determined. The SDS-PAGE protein bands were divided into 14 groups based on molecular weight. The relative distribution of proteins within these groups was used to characterize the strains. These distribution patterns were analysed by computing Pearson's correlation coefficient between strains, and by cluster analysis based on Euclidean distances and the unweighted pair-group method of arithmetic averages (UPGMA). The geometric mean of the similarities calculated by Pearson's correlation coefficient was 0.980 +/- 0.018 between the E. rhusiopathiae strains and 0.979 +/- 0.013 for E. tonsillarum strains. The value was 0.932 +/- 0.036 between the strains belonging to different species. However, a threshold value applicable for identification of a given strain to a species could not be established. Of the three strains of uncertain taxonomic position, the strains designated Rotzunge and Iszap 4 had a protein composition more similar to that of E. tonsillarum than to that of the E. rhusiopathiae type strain. The strain designated Pécs 56, which may be a member of a new species according to literature data, gave inconsistent results by the two methods used. The computerized evaluation method developed here is suitable for the comparison of the protein composition of the strains and for the construction of the protein similarity tree by cluster analysis.

  4. Human fibroblast strain with normal survival but abnormal postreplication repair after ultraviolet light irradiation

    SciTech Connect

    Doniger, J.; Barrett, S.F.; Robbins, J.H.

    1980-08-01

    Postreplication repair has been studied in ultraviolet light (UV-irradiated) fibroblast strains derived from eight apparently normal control donors and seven xeroderma pigmentosum patients. One control donor strain had an intermediate defect in postreplication repair similar to that in excision-deficient xeroderma pigmentosum fibroblasts. However, unlike the xeroderma pigmentosum strains, this control donor strain had normal UV-induced unscheduled DNA synthesis and normal survival after irradiation with UV. This unique fibroblast strain should be useful in studies designed to elucidate the possible role of postreplication repair in UV-induced carcinogenesis and mutagenesis.

  5. Virulence Attributes and Host Response Assays for Determining Pathogenic Potential of Pseudomonas Strains Used in Biotechnology.

    PubMed

    Tayabali, Azam F; Coleman, Gordon; Nguyen, Kathy C

    2015-01-01

    Pseudomonas species are opportunistically pathogenic to humans, yet closely related species are used in biotechnology applications. In order to screen for the pathogenic potential of strains considered for biotechnology applications, several Pseudomonas strains (P.aeruginosa (Pa), P.fluorescens (Pf), P.putida (Pp), P.stutzeri (Ps)) were compared using functional virulence and toxicity assays. Most Pa strains and Ps grew at temperatures between 28°C and 42°C. However, Pf and Pp strains were the most antibiotic resistant, with ciprofloxacin and colistin being the most effective of those tested. No strain was haemolytic on sheep blood agar. Almost all Pa, but not other test strains, produced a pyocyanin-like chromophore, and caused cytotoxicity towards cultured human HT29 cells. Murine endotracheal exposures indicated that the laboratory reference strain, PAO1, was most persistent in the lungs. Only Pa strains induced pro-inflammatory and inflammatory responses, as measured by elevated cytokines and pulmonary Gr-1 -positive cells. Serum amyloid A was elevated at ≥ 48 h post-exposure by only some Pa strains. No relationship was observed between strains and levels of peripheral leukocytes. The species designation or isolation source may not accurately reflect pathogenic potential, since the clinical strain Pa10752 was relatively nonvirulent, but the industrial strain Pa31480 showed comparable virulence to PAO1. Functional assays involving microbial growth, cytotoxicity and murine immunological responses may be most useful for identifying problematic Pseudomonas strains being considered for biotechnology applications.

  6. Virulence Attributes and Host Response Assays for Determining Pathogenic Potential of Pseudomonas Strains Used in Biotechnology

    PubMed Central

    Tayabali, Azam F.; Coleman, Gordon; Nguyen, Kathy C.

    2015-01-01

    Pseudomonas species are opportunistically pathogenic to humans, yet closely related species are used in biotechnology applications. In order to screen for the pathogenic potential of strains considered for biotechnology applications, several Pseudomonas strains (P.aeruginosa (Pa), P.fluorescens (Pf), P.putida (Pp), P.stutzeri (Ps)) were compared using functional virulence and toxicity assays. Most Pa strains and Ps grew at temperatures between 28°C and 42°C. However, Pf and Pp strains were the most antibiotic resistant, with ciprofloxacin and colistin being the most effective of those tested. No strain was haemolytic on sheep blood agar. Almost all Pa, but not other test strains, produced a pyocyanin-like chromophore, and caused cytotoxicity towards cultured human HT29 cells. Murine endotracheal exposures indicated that the laboratory reference strain, PAO1, was most persistent in the lungs. Only Pa strains induced pro-inflammatory and inflammatory responses, as measured by elevated cytokines and pulmonary Gr-1 -positive cells. Serum amyloid A was elevated at ≥ 48 h post-exposure by only some Pa strains. No relationship was observed between strains and levels of peripheral leukocytes. The species designation or isolation source may not accurately reflect pathogenic potential, since the clinical strain Pa10752 was relatively nonvirulent, but the industrial strain Pa31480 showed comparable virulence to PAO1. Functional assays involving microbial growth, cytotoxicity and murine immunological responses may be most useful for identifying problematic Pseudomonas strains being considered for biotechnology applications. PMID:26619347

  7. Strain measurements in a rotary engine housing

    NASA Technical Reports Server (NTRS)

    Lee, C. M.; Bond, T. H.; Addy, H. E.; Chun, K. S.; Lu, C. Y.

    1989-01-01

    The development of structural design tools for Rotary Combustion Engines (RCE) using Finite Element Modeling (FEM) requires knowledge about the response of engine materials to various service conditions. This paper describes experimental work that studied housing deformation as a result of thermal, pressure and mechanical loads. The measurement of thermal loads, clamping pressure, and deformation was accomplished by use of high-temperature strain gauges, thermocouples, and a high speed data acquisition system. FEM models for heat transfer stress analysis of the rotor housing will be verified and refined based on these experimental results.

  8. Development of strain-specific PCR primers for quantitative detection of Bacillus mesentericus strain TO-A in human feces.

    PubMed

    Sato, Naoki; Seo, Genichiro; Benno, Yoshimi

    2014-01-01

    Strain-specific polymerase chain reaction (PCR) primers for detection of Bacillus mesentericus strain TO-A (BM TO-A) were developed. The randomly amplified polymorphic DNA (RAPD) technique was used to produce potential strain-specific markers. A 991-bp RAPD marker found to be strain-specific was sequenced, and two primer pairs specific to BM TO-A were constructed based on this sequence. In addition, we explored a more specific DNA region using inverse PCR, and designed a strain-specific primer set for use in real-time quantitative PCR (qPCR). These primer pairs were tested against 25 Bacillus subtilis strains and were found to be strain-specific. After examination of the detection limit and linearity of detection of BM TO-A in feces, the qPCR method and strain-specific primers were used to quantify BM TO-A in the feces of healthy volunteers who had ingested 3×10(8) colony forming unit (CFU) of BM TO-A per day in tablets. During the administration period, BM TO-A was detected in the feces of all 24 subjects, and the average number of BM TO-A detected using the culture method and qPCR was about 10(4.8) and 10(5.8) cells per gram of feces, respectively. Using the qPCR method, BM TO-A was detected in the feces of half of the subjects 3 d after withdrawal, and was detected in the feces of only one subject 1 week after withdrawal. These results suggest that the qPCR method using BM TO-A strain-specific primers is useful for the quantitative detection of this strain in feces.

  9. An experimental/analytical comparison of strains in encapsulated assemblies

    SciTech Connect

    Guess, T.R.; Burchett, S.N.

    1991-11-01

    A combined experimental and analytical study of strains developed in encapsulated assemblies during casting, curing and thermal excursions is described. The experimental setup, designed to measure in situ strains, consisted of thin, closed-end, Kovar tubes that were instrumented with strain gages and thermocouples before being over-cast with a polymeric encapsulant. Four bisphenol A (three diethanolamine cured and one anhydride cured) epoxy-based materials and one urethane elastomeric material were studied. After cure of the encapsulant, tube strains were measured over the temperature range of {minus}55{degrees}C to 90{degrees}C. The thermal excursion experiments were then numerically modeled using finite element analyses and the computed strains were compared to the experimental strains. The predicted strains were over estimated (conservative) when a linear, elastic, temperature-dependent material model was assumed for the encapsulant and the stress free temperature T{sub i} was assumed to correspond to the cure temperature {Tc} of the encapsulant. Very good agreement was obtained with linear elastic calculations provided that the stress free temperature corresponded to the onset of the glassy-to-rubbery transition range of the encapsulant. Finally, excellent agreement was obtained in one of the materials (828/DEA) when a viscoelastic material model was utilized and a stress free temperature corresponding to the cure temperature was assumed. 13 refs., 20 figs., 3 tabs.

  10. Strain measurement in semiconductor heterostructures by scanning transmission electron microscopy.

    PubMed

    Müller, Knut; Rosenauer, Andreas; Schowalter, Marco; Zweck, Josef; Fritz, Rafael; Volz, Kerstin

    2012-10-01

    This article deals with the measurement of strain in semiconductor heterostructures from convergent beam electron diffraction patterns. In particular, three different algorithms in the field of (circular) pattern recognition are presented that are able to detect diffracted disc positions accurately, from which the strain in growth direction is calculated. Although the three approaches are very different as one is based on edge detection, one on rotational averages, and one on cross correlation with masks, it is found that identical strain profiles result for an In x Ga1-x N y As1-y /GaAs heterostructure consisting of five compressively and tensile strained layers. We achieve a precision of strain measurements of 7-9·10-4 and a spatial resolution of 0.5-0.7 nm over the whole width of the layer stack which was 350 nm. Being already very applicable to strain measurements in contemporary nanostructures, we additionally suggest future hardware and software designs optimized for fast and direct acquisition of strain distributions, motivated by the present studies.

  11. Energy scavenging strain absorber: application to kinetic dielectric elastomer generator

    NASA Astrophysics Data System (ADS)

    Jean-Mistral, C.; Beaune, M.; Vu-Cong, T.; Sylvestre, A.

    2014-03-01

    Dielectric elastomer generators (DEGs) are light, compliant, silent energy scavengers. They can easily be incorporated into clothing where they could scavenge energy from the human kinetic movements for biomedical applications. Nevertheless, scavengers based on dielectric elastomers are soft electrostatic generators requiring a high voltage source to polarize them and high external strain, which constitutes the two major disadvantages of these transducers. We propose here a complete structure made up of a strain absorber, a DEG and a simple electronic power circuit. This new structure looks like a patch, can be attached on human's wear and located on the chest, knee, elbow… Our original strain absorber, inspired from a sailing boat winch, is able to heighten the external available strain with a minimal factor of 2. The DEG is made of silicone Danfoss Polypower and it has a total area of 6cm per 2.5cm sustaining a maximal strain of 50% at 1Hz. A complete electromechanical analytical model was developed for the DEG associated to this strain absorber. With a poling voltage of 800V, a scavenged energy of 0.57mJ per cycle is achieved with our complete structure. The performance of the DEG can further be improved by enhancing the imposed strain, by designing a stack structure, by using a dielectric elastomer with high dielectric permittivity.

  12. Flexible Carbon Nanotube Films for High Performance Strain Sensors

    PubMed Central

    Kanoun, Olfa; Müller, Christian; Benchirouf, Abderahmane; Sanli, Abdulkadir; Dinh, Trong Nghia; Al-Hamry, Ammar; Bu, Lei; Gerlach, Carina; Bouhamed, Ayda

    2014-01-01

    Compared with traditional conductive fillers, carbon nanotubes (CNTs) have unique advantages, i.e., excellent mechanical properties, high electrical conductivity and thermal stability. Nanocomposites as piezoresistive films provide an interesting approach for the realization of large area strain sensors with high sensitivity and low manufacturing costs. A polymer-based nanocomposite with carbon nanomaterials as conductive filler can be deposited on a flexible substrate of choice and this leads to mechanically flexible layers. Such sensors allow the strain measurement for both integral measurement on a certain surface and local measurement at a certain position depending on the sensor geometry. Strain sensors based on carbon nanostructures can overcome several limitations of conventional strain sensors, e.g., sensitivity, adjustable measurement range and integral measurement on big surfaces. The novel technology allows realizing strain sensors which can be easily integrated even as buried layers in material systems. In this review paper, we discuss the dependence of strain sensitivity on different experimental parameters such as composition of the carbon nanomaterial/polymer layer, type of polymer, fabrication process and processing parameters. The insights about the relationship between film parameters and electromechanical properties can be used to improve the design and fabrication of CNT strain sensors. PMID:24915183

  13. Inelastic Strain Analysis of Solder Joint in NASA Fatigue Specimen

    NASA Technical Reports Server (NTRS)

    Dasgupta, Abhijit; Oyan, Chen

    1991-01-01

    The solder fatigue specimen designed by NASA-GSFC/UNISYS is analyzed in order to obtain the inelastic strain history during two different representative temperature cycles specified by UNISYS. In previous reports (dated July 25, 1990, and November 15, 1990), results were presented of the elastic-plastic and creep analysis for delta T = 31 C cycle, respectively. Subsequent results obtained during the current phase, from viscoplastic finite element analysis of the solder fatigue specimen for delta T = 113 C cycle are summarized. Some common information is repeated for self-completeness. Large-deformation continuum formulations in conjunction with a standard linear solid model is utilized for modeling the solder constitutive creep-plasticity behavior. Relevant material properties are obtained from the literature. Strain amplitudes, mean strains, and residual strains (as well as stresses) accumulated due to a representative complete temperature cycle are obtained as a result of this analysis. The partitioning between elastic strains, time-independent inelastic (plastic) strains, and time-dependent inelastic (creep) strains is also explicitly obtained for two representative cycles. Detailed plots are presented for two representative temperature cycles. This information forms an important input for fatigue damage models, when predicting the fatigue life of solder joints under thermal cycling

  14. Differences in susceptibility of mouse strains to tetrodotoxin.

    PubMed

    Suzuki, Hodaka

    2016-09-01

    The mouse bioassay for tetrodotoxin has been used for many years in Japan. To the best of our knowledge, however, there have only been a few reports that have specifically investigated differences in susceptibility to tetrodotoxin among mouse strains. In this study, we investigated the response of various mouse strains to tetrodotoxin. Tetrodotoxin solution was injected intraperitoneally into male mice of 5 inbred strains (A/J, BALB/c, C3H/He, C57BL/6, and DBA/2) and male and female mice of 2 non-inbred strains (ddY and ICR). Significant differences in susceptibility to tetrodotoxin were found among the mouse strains tested. In comparison to the ddY male mice, which are designated to be used in the Japanese reference method, the 5 inbred strains of mice tested were significantly more resistant to tetrodotoxin. However, no significant differences in tetrodotoxin susceptibility were observed between ddY male and female mice or between ddY male mice and ICR male and female mice. These results indicate that the users of the mouse bioassay should pay attention to differences in mouse strain in susceptibility to tetrodotoxin.

  15. Controlling surface reactions with nanopatterned surface elastic strain.

    PubMed

    Li, Zhisheng; Potapenko, Denis V; Osgood, Richard M

    2015-01-27

    The application of elastic lattice strain is a promising approach for tuning material properties, but the attainment of a systematic approach for introducing a high level of strain in materials so as to study its effects has been a major challenge. Here we create an array of intense locally varying strain fields on a TiO2 (110) surface by introducing highly pressurized argon nanoclusters at 6-20 monolayers under the surface. By combining scanning tunneling microscopy imaging and the continuum mechanics model, we show that strain causes the surface bridge-bonded oxygen vacancies (BBOv), which are typically present on this surface, to be absent from the strained area and generates defect-free regions. In addition, we find that the adsorption energy of hydrogen binding to oxygen (BBO) is significantly altered by local lattice strain. In particular, the adsorption energy of hydrogen on BBO rows is reduced by ∼ 35 meV when the local crystal lattice is compressed by ∼ 1.3%. Our results provide direct evidence of the influence of strain on atomic-scale surface chemical properties, and such effects may help guide future research in catalysis materials design.

  16. High-sensitivity strain visualization using electroluminescence technologies

    NASA Astrophysics Data System (ADS)

    Xu, Jian; Jo, Hongki

    2016-04-01

    Visualizing mechanical strain/stress changes is an emerging area in structural health monitoring. Several ways are available for strain change visualization through the color/brightness change of the materials subjected to the mechanical stresses, for example, using mechanoluminescence (ML) materials and mechanoresponsive polymers (MRP). However, these approaches were not effectively applicable for civil engineering system yet, due to insufficient sensitivity to low-level strain of typical civil structures and limitation in measuring both static and dynamic strain. In this study, design and validation for high-sensitivity strain visualization using electroluminescence technologies are presented. A high-sensitivity Wheatstone bridge, of which bridge balance is precisely controllable circuits, is used with a gain-adjustable amplifier. The monochrome electroluminescence (EL) technology is employed to convert both static and dynamic strain change into brightness/color change of the EL materials, through either brightness change mode (BCM) or color alternation mode (CAM). A prototype has been made and calibrated in lab, the linearity between strain and brightness change has been investigated.

  17. Strain and elongation of the human semitendinosus muscle - tendon unit.

    PubMed

    Kellis, Eleftherios; Patsika, Glykeria; Karagiannidis, Evaggelos

    2013-12-01

    The semitendinosus (ST) consists of a long distal tendon and it is divided in two parts by a tendinous inscription (TI). The purpose of this study was to quantify strain and elongation of the TI and the distal tendon of ST. Fourteen subjects performed ramp isometric contractions of the knee flexors at 0°, 45° and 90° of knee flexion. Two ultrasound probes were used to visualize the displacement of the distal tendon and selected points across the TI and aponeuroses. Three-way analysis of variance designs indicated that: (a) strain and elongation of the ST distal muscle-tendon junction were higher than that of the aponeurosis - TI junction points (p < 0.05) (b) the long arm of the TI reach strain of 49.86 ± 7.77% which was significantly (p < 0.05) higher than that displayed by the short arm (28.35 ± 0.59%) (c) Strain of tendinous and TI-aponeuroses segments significantly increased from 90° to 0° of knee flexion while the inverse was observed for the TI arm length (p < 0.05). (d) Tendon strain was significantly higher than strain of the TI-aponeuroses segments at 45° and 90° of knee flexion while the opposite was observed at 0° of knee flexion. The arrangement of TI along ST length results in differential local strains, indicating that the mechanical properties of the ST muscle are affected by tendon, aponeuroses and tendinous inscription interactions.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. QUANTIFICATION OF SIDEROPHORE AND HEMOLYSIN FROM STACHYBOTRYS CHARTARUM STRAINS, INCLUDING A STRAIN ISOLATED FROM THE LUNG OF A CHILD WITH PULMONARY HEMORRHAGE AND HEMOSIDEROSIS

    EPA Science Inventory

    A strain of Stachybotrys chartarum was recently isolated from the lung of a pulmonary hemorrhage and hemosiderosis (PH) patient in Texas (designated the Houston strain). This is the first time that S. chartarum has been isolated from the lung of a PH patient. In this study, the ...

  3. Electric circuit model for strained-layer epitaxy

    NASA Astrophysics Data System (ADS)

    Kujofsa, Tedi; Ayers, John E.

    2016-11-01

    For the design and analysis of a strained-layer semiconductor device structure, the equilibrium strain profile may be determined numerically by energy minimization but this method is computationally intense and non-intuitive. Here we present an electric circuit model approach for the equilibrium analysis of an epitaxial stack, in which each sublayer may be represented by an analogous configuration involving a current source, a resistor, a voltage source, and an ideal diode. The resulting node voltages in the analogous electric circuit correspond to the equilibrium strains in the original epitaxial structure. This new approach enables analysis using widely accessible circuit simulators, and an intuitive understanding of electric circuits may be translated to the relaxation of strained-layer structures. In this paper, we describe the mathematical foundation of the electrical circuit model and demonstrate its application to epitaxial layers of Si1-x Ge x grown on a Si (001) substrate.

  4. Carbon nanotube strain sensors for wearable patient monitoring applications

    NASA Astrophysics Data System (ADS)

    Abraham, Jose K.; Aryasomayajula, Lavanya; Whitchurch, Ashwin; Varadan, Vijay K.

    2008-03-01

    Wearable health monitoring systems have recently attracted widespread interest for their application in long term patient monitoring. Wireless wearable technology enables continuous observation of patients while they perform their normal everyday activities. This involves the development of flexible and conformable sensors that could be easily integrated to the smart fabrics. Carbon nanotubes are found to be one of the ideal candidate materials for the design of multifunctional e-textiles because of their capability to change conductance based on any mechanical deformation as well as surface functionalization. This paper presents the development and characterization of a carbon nanotube (CNT)-polymer nanocomposite flexible strain sensor for wearable health monitoring applications. These strain sensors can be used to measure the respiration rhythm which is a vital signal required in health monitoring. A number of strain sensor prototypes with different CNT compositions have been fabricated and their characteristics for both static as well as dynamic strain have been measured.

  5. Magnetic Implosion for Novel Strength Measurements at High Strain Rates

    SciTech Connect

    Lee, H.; Preston, D.L.; Bartsch, R.R.; Bowers, R.L.; Holtkamp, D.; Wright, B.L.

    1998-10-19

    Recently Lee and Preston have proposed to use magnetic implosions as a new method for measuring material strength in a regime of large strains and high strain rates inaccessible to previously established techniques. By its shockless nature, this method avoids the intrinsic difficulties associated with an earlier approach using high explosives. The authors illustrate how the stress-strain relation for an imploding liner can be obtained by measuring the velocity and temperature history of its inner surface. They discuss the physical requirements that lead us to a composite liner design applicable to different test materials, and also compare the code-simulated prediction with the measured data for the high strain-rate experiments conducted recently at LANL. Finally, they present a novel diagnostic scheme that will enable us to remove the background in the pyrometric measurement through data reduction.

  6. Thin film strain gage development program. Final program

    SciTech Connect

    Grant, H.P.; Przybyszewski, J.S.; Anderson, W.L.; Claing, R.G.

    1983-12-01

    Sputtered thin-film dynamic strain 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 strain-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 strain gage installations, and any alteration of the aerodynamic, thermal, or structural performance of the blade is correspondingly reduced, dynamic strain 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.

  7. Electronic measurement of strain effects on spin transport in silicon

    NASA Astrophysics Data System (ADS)

    Qing, Lan; Tinkey, Holly; Appelbaum, Ian

    Spin transport in silicon is limited by the Elliott-Yafet spin relaxation mechanism, which is driven by scattering between degenerate conduction band valleys. Mechanical strain along a valley axis partially breaks this degeneracy, and will ultimately quench intervalley spin relaxation for transitions between states on orthogonal axes. Using a custom-designed and constructed strain probe, we study the effects of uniaxial compressive strain along the < 100 > direction on ballistic tunnel junction devices used to inject spin-polarized electrons into silicon. The effects of strain-induced valley splitting will be presented and compared to our theoretical model. This work is supported by the Office of Naval Research under Contract No. N000141410317, the National Science Foundation under Contract No. ECCS-1231855, the Defense Threat Reduction Agency under Contract No. HDTRA1-13-1-0013, and the Maryland NanoCenter.

  8. Laser-based strain measurements for high temperature applications

    NASA Technical Reports Server (NTRS)

    Lant, Christian T.

    1992-01-01

    The Instrumentation and Control Technology Division at NASA Lewis Research Center has developed a high performance optical strain measurement system for high temperature applications using wires and fibers. The system is based on Yamaguchi's two-beam speckle-shift strain measurement technique. The system automatically calculates surface strains at a rate of 5 Hz using a digital signal processor in a high speed micro-computer. The system is fully automated, and can be operated remotely. This report describes the speckle-shift technique and the latest NASA system design. It also shows low temperature strain test results obtained from small diameter tungsten, silicon carbide, and sapphire specimens. These specimens are of interest due to their roles in composite materials research at NASA Lewis.

  9. Study of High Strain Rate Response of Composites

    NASA Technical Reports Server (NTRS)

    Gilat, Amos

    2003-01-01

    The objective of the research was to continue the experimental study of the effect of strain rate on mechanical response (deformation and failure) of epoxy resins and carbon fibers/epoxy matrix composites, and to initiate a study of the effects of temperature by developing an elevated temperature test. The experimental data provide the information needed for NASA scientists for the development of a nonlinear, rate dependent deformation and strength models for composites that can subsequently be used in design. This year effort was directed into testing the epoxy resin. Three types of epoxy resins were tested in tension and shear at various strain rates that ranges from 5 x 10(exp -5), to 1000 per second. Pilot shear experiments were done at high strain rate and an elevated temperature of 80 C. The results show that all, the strain rate, the mode of loading, and temperature significantly affect the response of epoxy.

  10. Genotyping of Bacillus cereus strains by microarray-based resequencing.

    PubMed

    Zwick, Michael E; Kiley, Maureen P; Stewart, Andrew C; Mateczun, Alfred; Read, Timothy D

    2008-07-02

    The ability to distinguish microbial pathogens from closely related but nonpathogenic strains is key to understanding the population biology of these organisms. In this regard, Bacillus anthracis, the bacterium that causes inhalational anthrax, is of interest because it is closely related and often difficult to distinguish from other members of the B. cereus group that can cause diverse diseases. We employed custom-designed resequencing arrays (RAs) based on the genome sequence of Bacillus anthracis to generate 422 kb of genomic sequence from a panel of 41 Bacillus cereus sensu lato strains. Here we show that RAs represent a "one reaction" genotyping technology with the ability to discriminate between highly similar B. anthracis isolates and more divergent strains of the B. cereus s.l. Clade 1. Our data show that RAs can be an efficient genotyping technology for pre-screening the genetic diversity of large strain collections to selected the best candidates for whole genome sequencing.

  11. Genotyping of Bacillus cereus Strains by Microarray-Based Resequencing

    PubMed Central

    Zwick, Michael E.; Kiley, Maureen P.; Stewart, Andrew C.; Mateczun, Alfred; Read, Timothy D.

    2008-01-01

    The ability to distinguish microbial pathogens from closely related but nonpathogenic strains is key to understanding the population biology of these organisms. In this regard, Bacillus anthracis, the bacterium that causes inhalational anthrax, is of interest because it is closely related and often difficult to distinguish from other members of the B. cereus group that can cause diverse diseases. We employed custom-designed resequencing arrays (RAs) based on the genome sequence of Bacillus anthracis to generate 422 kb of genomic sequence from a panel of 41 Bacillus cereus sensu lato strains. Here we show that RAs represent a “one reaction” genotyping technology with the ability to discriminate between highly similar B. anthracis isolates and more divergent strains of the B. cereus s.l. Clade 1. Our data show that RAs can be an efficient genotyping technology for pre-screening the genetic diversity of large strain collections to selected the best candidates for whole genome sequencing. PMID:18596941

  12. Bioprocessing of Stichococcus bacillaris strain siva2011

    PubMed Central

    2014-01-01

    Background Globally, the development of a cost-effective long-term renewable energy infrastructure is one of the most challenging problems faced by society today. Microalgae are rich in potential biofuel substrates such as lipids, including triacylglycerols (TAGs). Some of these algae also biosynthesize small molecule hydrocarbons. These hydrocarbons can often be used as liquid fuels, often with more versatility and by a more direct approach than some TAGs. However, the appropriate TAGs, accumulated from microalgae biomass, can be used as substrates for different kinds of renewable liquid fuels such as biodiesel and jet fuel. Results This article describes the isolation and identification of a lipid-rich, hydrocarbon-producing alga, Stichococcus bacillaris strain siva2011, together with its bioprocessing, hydrocarbon and fatty acid methyl ester (FAME) profiles. The S. bacillaris strain siva2011 was scaled-up in an 8 L bioreactor with 0.2% CO2. The C16:0, C16:3, C18:1, C18:2 and C18:3 were 112.2, 9.4, 51.3, 74.1 and 69.2 mg/g dry weight (DW), respectively. This new strain produced a significant amount of biomass of 3.79 g/L DW on day 6 in the 8 L bioreactor and also produced three hydrocarbons. Conclusions A new oil-rich microalga S. bacillaris strain siva2011 was discovered and its biomass has been scaled-up in a newly designed balloon-type bioreactor. The TAGs and hydrocarbons produced by this organism could be used as substrates for jet fuel or biodiesel. PMID:24731690

  13. Technical note: development of a quantitative PCR method for monitoring strain dynamics during yogurt manufacture.

    PubMed

    Miller, D M; Dudley, E G; Roberts, R F

    2012-09-01

    Yogurt starter cultures may consist of multiple strains of Lactobacillus delbrueckii ssp. bulgaricus (LB) and Streptococcus thermophilus (ST). Conventional plating methods for monitoring LB and ST levels during yogurt manufacture do not allow for quantification of individual strains. The objective of the present work was to develop a quantitative PCR method for quantification of individual strains in a commercial yogurt starter culture. Strain-specific primers were designed for 2 ST strains (ST DGCC7796 and ST DGCC7710), 1 LB strain (DGCC4078), and 1 Lactobacillus delbrueckii ssp. lactis strain (LL; DGCC4550). Primers for the individual ST and LB strains were designed to target unique DNA sequences in clustered regularly interspersed short palindromic repeats. Primers for LL were designed to target a putative mannitol-specific IIbC component of the phosphotransferase system. Following evaluation of primer specificity, standard curves relating cell number to cycle threshold were prepared for each strain individually and in combination in yogurt mix, and no significant differences in the slopes were observed. Strain balance data was collected for yogurt prepared at 41 and 43°C to demonstrate the potential application of this method.

  14. SVAS3: Strain Vector Aided Sensorization of Soft Structures

    PubMed Central

    Culha, Utku; Nurzaman, Surya G.; Clemens, Frank; Iida, Fumiya

    2014-01-01

    Soft material structures exhibit high deformability and conformability which can be useful for many engineering applications such as robots adapting to unstructured and dynamic environments. However, the fact that they have almost infinite degrees of freedom challenges conventional sensory systems and sensorization approaches due to the difficulties in adapting to soft structure deformations. In this paper, we address this challenge by proposing a novel method which designs flexible sensor morphologies to sense soft material deformations by using a functional material called conductive thermoplastic elastomer (CTPE). This model-based design method, called Strain Vector Aided Sensorization of Soft Structures (SVAS3), provides a simulation platform which analyzes soft body deformations and automatically finds suitable locations for CTPE-based strain gauge sensors to gather strain information which best characterizes the deformation. Our chosen sensor material CTPE exhibits a set of unique behaviors in terms of strain length electrical conductivity, elasticity, and shape adaptability, allowing us to flexibly design sensor morphology that can best capture strain distributions in a given soft structure. We evaluate the performance of our approach by both simulated and real-world experiments and discuss the potential and limitations. PMID:25036332

  15. Compact Simultaneous-beam Optical Strain Measurement System, Phase 5

    NASA Technical Reports Server (NTRS)

    Lant, Christian T.

    1994-01-01

    Recent advances on the laser speckle strain measurement system under development at NASA Lewis Research Center have resulted in a compact, easy-to-use measurement package having many performance improvements over previous systems. NASA has developed this high performance optical strain measurement system for high temperature material testing applications. The system is based on I. Yamaguchi's two-beam speckle-shift strain measurement theory, and uses a new optical design that allows simultaneous recording of laser speckle patterns. This design greatly improves system response over previous implementations of the two-beam speckle-shift technique. The degree of immunity to transient rigid body motions is no longer dependent on the data transfer rate. The system automatically calculates surface strains at a frequency of about 5 Hz using a high speed digital signal processor in a personal computer. This system is fully automated, and can be operated remotely. This report describes the designs and methods used by the system, and shows low temperature strain test results obtained from small diameter tungsten-rhenium and palladium-chrome wires.

  16. [Breeding of robust industrial ethanol-tolerant Saccharomyces cerevisiae strain by artificial zinc finger protein library].

    PubMed

    Ma, Cui; Zhao, Xinqing; Li, Qian; Zhang, Mingming; Kim, Jin Soo; Bai, Fengwu

    2013-05-01

    Breeding of robust industrial Saccharomyces cerevisiae strains with high ethanol tolerance is of great significance for efficient fuel ethanol production. Zinc finger proteins play important roles in gene transcription and translation, and exerting control on the regulation of multiple genes. The sequence and localization of the zinc finger motif can be designed and engineered, and the artificial zinc finger protein can be used to regulate celluar metabolism. Stress tolerance of microbial strains is related to multiple genes. Therefore, it is possible to use artificially-designed zinc finger proteins to breed stress tolerant strains. In this study, a library containing artificial zinc finger protein encoding genes was transformed into the model yeast strain S288c. A recombinant strain named M01 with improved ethanol tolerance was obtained. The plasmid in M01 was isolated, and then transformed into the industrial yeast strain Sc4126. Ethanol tolerance of the recombinant strain of Sc4126 were significantly improved. When high gravity ethanol fermentation using 250 g/L glucose was performed, comparing with the wild-type strain, fermentation time of the recombinant strain was decreased by 24 h and the final ethanol concentration was enhanced by 6.3%. The results of this study demonstrate that artificial zinc finger proteins are able to exert control on stress tolerance of yeast strains, and these results provide basis to construct robust industrial yeast strains for efficient ethanol fermentation.

  17. 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)

  18. Magnetic Domain Strain Sensor Program

    DTIC Science & Technology

    1990-08-01

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

  19. 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)

  20. Strain Wave during the Transient Process of Fault Unstable Slip

    NASA Astrophysics Data System (ADS)

    Guo, L.; Liu, L.

    2011-12-01

    The "stick-slip" model was proposed as an important mechanism for shallow-focus earthquakes. The study on the transient process of fault unstable slip failure is helpful for understanding the earthquake preparatory process, the mechanism of energy released, the precursor and after shake effect. Double shear frictional experiments are conducted for simulating "stick-slip" phenomenon, and a specially designed multi-channel super dynamic strain field observation system is employed to acquire dada continuously with the sample rate of 3,400 samples/second. The rock deformation process can be recorded in detail, especially in the moment of unstable slip (The unstable slip duration is less than two second in experiments). The strain results from super dynamic strain field observation system show that multi-frequency components and tremendous amplitude fluctuation are included in strain signals along the fault. There are three clear phases during the unstable slip progress: pre-slip (phase I), high-frequency strain vibration (phase II) and strain regulating to stop (phase III). Each phase has its own characteristics on duration, strain rate, frequency, amplitude and energy release. There are strong fluctuations in duration of approximately 70ms in phase II. The frequency and maximum amplitude are 300-400Hz and 150~300μɛ respectively. Main strain energy release takes place at phase II, less than one-tenth of the total slip time, so that the whole course of dislocation or stress drop would not be taken as earthquake simply at least in laboratory. The phase characteristic of the strain wave is probably its inherent attribute of unstable slip process and independent of dynamical loading conditions. The elastic rebound phenomena, considered as one classic earthquake generation model, can be observed clearly by analyzing the rotation of the principal strain axis with strain variation. The rotated angle ranges from 5° to 15° typically. The value and location of precursor slip

  1. 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

  2. Interpretation of large-strain geophysical crosshole tests

    SciTech Connect

    Drnevich, V.P.; Salgado, R.; Ashmawy, A.; Grant, W.P.; Vallenas, P.

    1995-10-01

    At sites in earthquake-prone areas, the nonlinear dynamic stress-strain behavior of soil with depth is essential for earthquake response analyses. A seismic crosshole test has been developed where large dynamic forces are applied in a borehole. These forces generate shear strains in the surrounding soil that are well into the nonlinear range. The shear strain amplitudes decrease with distance from the source. Velocity sensors located in three additional holes at various distances from the source hole measure the particle velocity and the travel time of the shear wave from the source. This paper provides an improved, systematic interpretation scheme for the data from these large-strain geophysical crosshole tests. Use is made of both the measured velocities at each sensor and the travel times. The measured velocity at each sensor location is shown to be a good measure of the soil particle velocity at that location. Travel times to specific features on the velocity time history, such as first crossover, are used to generate travel time curves for the waves which are nonlinear. At some distance the amplitudes reduce to where the stress-strain behavior is essentially linear and independent of strain amplitude. This fact is used together with the measurements at the three sensor locations in a rational approach for fitting curves of shear wave velocity versus distance from the source hole that allow the determination of the shear wave velocity and the shear strain amplitude at each of the sensor locations as well as the shear wave velocity associated with small-strain (linear) behavior. The method is automated using off-the-shelf PC-based software. The method is applied to large-strain crosshole tests performed as part of the studies for the design and construction of the proposed Multi-Function Waste Tank Facility planned for Hanford Site.

  3. Two-Color Laser Speckle Shift Strain Measurement System

    NASA Technical Reports Server (NTRS)

    Tuma, Margaret L.; Krasowski, Michael J.; Oberle, Lawrence G.; Greer, Lawrence C., III; Spina, Daniel; Barranger, John

    1996-01-01

    A two color laser speckle shift strain measurement system based on the technique of Yamaguchi was designed. The dual wavelength light output from an Argon Ion laser was coupled into two separate single-mode optical fibers (patchcords). The output of the patchcords is incident on the test specimen (here a structural fiber). Strain on the fiber, in one direction, is produced using an Instron 4502. Shifting interference patterns or speckle patterns will be detected at real-time rates using 2 CCD cameras with image processing performed by a hardware correlator. Strain detected in fibers with diameters from 21 microns to 143 microns is expected to be resolved to 15 mu epsilon. This system was designed to be compact and robust and does not require surface preparation of the structural fibers.

  4. High Strain Rate Behavior of Polymer Matrix Composites Analyzed

    NASA Technical Reports Server (NTRS)

    Goldberg, Robert K.; Roberts, Gary D.

    2001-01-01

    Procedures for modeling the high-speed impact of composite materials are needed for designing reliable composite engine cases that are lighter than the metal cases in current use. The types of polymer matrix composites that are likely to be used in such an application have a deformation response that is nonlinear and that varies with strain rate. To characterize and validate material models that could be used in the design of impactresistant engine cases, researchers must obtain material data over a wide variety of strain rates. An experimental program has been carried out through a university grant with the Ohio State University to obtain deformation data for a representative polymer matrix composite for strain rates ranging from quasi-static to high rates of several hundred per second. This information has been used to characterize and validate a constitutive model that was developed at the NASA Glenn Research Center.

  5. Fermentation characteristics of Dekkera bruxellensis strains.

    PubMed

    Blomqvist, Johanna; Eberhard, Thomas; Schnürer, Johan; Passoth, Volkmar

    2010-07-01

    The influence of pH, temperature and carbon source (glucose and maltose) on growth rate and ethanol yield of Dekkera bruxellensis was investigated using a full-factorial design. Growth rate and ethanol yield were lower on maltose than on glucose. In controlled oxygen-limited batch cultivations, the ethanol yield of the different combinations varied from 0.42 to 0.45 g (g glucose)(-1) and growth rates varied from 0.037 to 0.050 h(-1). The effect of temperature on growth rate and ethanol yield was negligible. It was not possible to model neither growth rate nor ethanol yield from the full-factorial design, as only marginal differences were observed in the conditions tested. When comparing three D. bruxellensis strains and two industrial isolates of Saccharomyces cerevisiae, S. cerevisiae grew five times faster, but the ethanol yields were 0-13% lower. The glycerol yields of S. cerevisiae strains were up to six-fold higher compared to D. bruxellensis, and the biomass yields reached only 72-84% of D. bruxellensis. Our results demonstrate that D. bruxellensis is robust to large changes in pH and temperature and may have a more energy-efficient metabolism under oxygen limitation than S. cerevisiae.

  6. Development of a fiber optic pavement subgrade strain measurement system

    NASA Astrophysics Data System (ADS)

    Miller, Craig Emerson

    2000-11-01

    This dissertation describes the development of a fiber optic sensing system to measure strains within the soil subgrade of highway pavements resulting from traffic loads. The motivation to develop such a device include improvements to: (1)all phases of pavement design, (2)theoretical models used to predict pavement performance, and (3)pavement rehabilitation. The design of the sensing system encompasses selecting an appropriate transducer design as well as the development of optimal optical and demodulation systems. The first is spring based, which attempts to match its spring stiffness to that of the soil-data indicate it is not an optimal transducer design. The second transducer implements anchoring plates attached to two telescoping tubes which allows the soil to be compacted to a desired density between the plates to dictate the transducer's behavior. Both transducers include an extrinsic Fabry- Perot cavity to impose the soil strains onto a phase change of the optical signal propagating through the cavity. The optical system includes a low coherence source and allows phase modulation via path length stretching by adding a second interferometer in series with the transducer, resulting in a path matched differential interferometer. A digitally implemented synthetic heterodyne demodulator based on a four step phase stepping algorithm is used to obtain unambiguous soil strain information from the displacement of the Fabry-Perot cavity. The demodulator is calibrated and characterized by illuminating the transducer with a second long coherence source of different wavelength. The transducer using anchoring plates is embedded within cylindrical soil specimens of varying soil types and soil moisture contents. Loads are applied to the specimen and resulting strains are measured using the embedded fiber optic gage and LVDTs attached to the surface of the specimen. This experimental verification is substantiated using a finite element analysis to predict any differences

  7. Repetitive strain injury.

    PubMed

    Helliwell, P S; Taylor, W J

    2004-08-01

    Pain in the forearm is relatively common in the community. In the workplace forearm pain is associated with work involving frequent repetition, high forces, and prolonged abnormal postures. Nevertheless, other factors are involved in the presentation and the continuation of the pain. Notable among these factors are psychosocial issues and the workplace environment-the attitude to workers and their welfare, the physical conditions, and design of the job. Primary prevention may be effective but active surveillance is important with early intervention and an active management approach. Physical treatments have not been extensively evaluated. In the established case, management should be multidisciplinary, addressing physical aspects of the job but also addressing the "yellow, blue, and black flags" which should be viewed as obstacles to recovery. For the worker "on sick" a dialogue should be established between the worker, the primary care physician, and the workplace. Return to work should be encouraged and facilitated by medical interventions and light duty options. Rehabilitation programmes may be of use in chronic cases.

  8. Role of scaffold network in controlling strain and functionalities of nanocomposite films

    DOE PAGES

    Chen, Aiping; Hu, Jia -Mian; Lu, Ping; ...

    2016-06-10

    One novel approach to manipulating functionalities in correlated complex oxides is strain. However, significant epitaxial strain can only be achieved in ultrathin layers. We show that, under direct lattice matching framework, large and uniform vertical strain up to 2% can be achieved to significantly modify the magnetic anisotropy, magnetism, and magnetotransport properties in heteroepitaxial nanoscaffold films, over a few hundred nanometers in thickness. Comprehensive designing principles of large vertical strain have been proposed. Phase-field simulations not only reveal the strain distribution but also suggest that the ultimate strain is related to the vertical interfacial area and interfacial dislocation density. Moreover,more » by changing the nanoscaffold density and dimension, the strain and the magnetic properties can be tuned. The established correlation among the vertical interface—strain—properties in nanoscaffold films can consequently be used to tune other functionalities in a broad range of complex oxide films far beyond critical thickness.« less

  9. Role of scaffold network in controlling strain and functionalities of nanocomposite films

    SciTech Connect

    Chen, Aiping; Hu, Jia -Mian; Lu, Ping; Yang, Tiannan; Zhang, Wenrui; Li, Leigang; Ahmed, T.; Enriquez, E.; Weigand, M.; Su, Qing; Wang, Haiyan; Zhu, J. -X.; MacManus-Driscoll, Judith L.; Chen, Long -Qing; Yarotski, D.; Jia, Q.

    2016-06-10

    One novel approach to manipulating functionalities in correlated complex oxides is strain. However, significant epitaxial strain can only be achieved in ultrathin layers. We show that, under direct lattice matching framework, large and uniform vertical strain up to 2% can be achieved to significantly modify the magnetic anisotropy, magnetism, and magnetotransport properties in heteroepitaxial nanoscaffold films, over a few hundred nanometers in thickness. Comprehensive designing principles of large vertical strain have been proposed. Phase-field simulations not only reveal the strain distribution but also suggest that the ultimate strain is related to the vertical interfacial area and interfacial dislocation density. Moreover, by changing the nanoscaffold density and dimension, the strain and the magnetic properties can be tuned. The established correlation among the vertical interface—strain—properties in nanoscaffold films can consequently be used to tune other functionalities in a broad range of complex oxide films far beyond critical thickness.

  10. Role of scaffold network in controlling strain and functionalities of nanocomposite films

    PubMed Central

    Chen, Aiping; Hu, Jia-Mian; Lu, Ping; Yang, Tiannan; Zhang, Wenrui; Li, Leigang; Ahmed, Towfiq; Enriquez, Erik; Weigand, Marcus; Su, Qing; Wang, Haiyan; Zhu, Jian-Xin; MacManus-Driscoll, Judith L.; Chen, Long-Qing; Yarotski, Dmitry; Jia, Quanxi

    2016-01-01

    Strain is a novel approach to manipulating functionalities in correlated complex oxides. However, significant epitaxial strain can only be achieved in ultrathin layers. We show that, under direct lattice matching framework, large and uniform vertical strain up to 2% can be achieved to significantly modify the magnetic anisotropy, magnetism, and magnetotransport properties in heteroepitaxial nanoscaffold films, over a few hundred nanometers in thickness. Comprehensive designing principles of large vertical strain have been proposed. Phase-field simulations not only reveal the strain distribution but also suggest that the ultimate strain is related to the vertical interfacial area and interfacial dislocation density. By changing the nanoscaffold density and dimension, the strain and the magnetic properties can be tuned. The established correlation among the vertical interface—strain—properties in nanoscaffold films can consequently be used to tune other functionalities in a broad range of complex oxide films far beyond critical thickness. PMID:27386578

  11. Shotcrete in tunnel design

    SciTech Connect

    Golser, J.; Galler, R.; Schubert, P.; Rabensteiner, K.

    1995-12-31

    Shotcrete is an important structural element for tunnel support. Green shotcrete is exposed to compression strain rates and tunnel design requires a realistic material law for shotcrete. A modified rate of flow method simulates shotcrete behavior very well and can be incorporated in Finite Element calculations.

  12. IDENTIFICATION OF A FLAVOBACTERIUM STRAIN VIRULENT AGAINT GIARDIA LAMBLIA CYSTS

    EPA Science Inventory

    We have isolated a bacterial strain capable of killing the cyst form of Giardia lamblia, from a Kentucky stream. This bacterium, designated Sun4, is a Gram negative, aerobic rod which produces a yellow pigment, but not of the flexirubin-type. Although true gliding motility has no...

  13. Mutant strain of C. acetobutylicum and process for making butanol

    DOEpatents

    Jain, Mahendra K.; Beacom, Daniel; Datta, Rathin

    1993-01-01

    A biologically pure asporogenic mutant of Clostridium acetobutylicum is produced by growing sporogenic C. acetobutylicum ATCC 4259 and treating the parent strain with ethane methane sulfonate. The mutant which as been designated C. acetobutylicum ATCC 55025 is useful in an improved ABE fermentation process, and produces high concentrations of butanol and total solvents.

  14. Compliant intracortical implants reduce strains and strain rates in brain tissue in vivo

    NASA Astrophysics Data System (ADS)

    Sridharan, Arati; Nguyen, Jessica K.; Capadona, Jeffrey R.; Muthuswamy, Jit

    2015-06-01

    Objective. The objective of this research is to characterize the mechanical interactions of (1) soft, compliant and (2) non-compliant implants with the surrounding brain tissue in a rodent brain. Understanding such interactions will enable the engineering of novel materials that will improve stability and reliability of brain implants. Approach. Acute force measurements were made using a load cell in n = 3 live rats, each with 4 craniotomies. Using an indentation method, brain tissue was tested for changes in force using established protocols. A total of 4 non-compliant, bare silicon microshanks, 3 non-compliant polyvinyl acetate (PVAc)-coated silicon microshanks, and 6 compliant, nanocomposite microshanks were tested. Stress values were calculated by dividing the force by surface area and strain was estimated using a linear stress-strain relationship. Micromotion effects from breathing and vascular pulsatility on tissue stress were estimated from a 5 s interval of steady-state measurements. Viscoelastic properties were estimated using a second-order Prony series expansion of stress-displacement curves for each shank. Main results. The distribution of strain values imposed on brain tissue for both compliant nanocomposite microshanks and PVAc-coated, non-compliant silicon microshanks were significantly lower compared to non-compliant bare silicon shanks. Interestingly, step-indentation experiments also showed that compliant, nanocomposite materials significantly decreased stress relaxation rates in the brain tissue at the interface (p < 0.05) compared to non-compliant silicon and PVAc-coated silicon materials. Furthermore, both PVAc-coated non-compliant silicon and compliant nanocomposite shanks showed significantly reduced (by 4-5 fold) stresses due to tissue micromotion at the interface. Significance. The results of this study showed that soft, adaptive materials reduce strains and strain rates and micromotion induced stresses in the surrounding brain tissue

  15. 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.

  16. 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.

  17. Strains and Stressors: An Analysis of Touchscreen Learning in Genetically Diverse Mouse Strains

    PubMed Central

    Graybeal, Carolyn; Bachu, Munisa; Mozhui, Khyobeni; Saksida, Lisa M.; Bussey, Timothy J.; Sagalyn, Erica; Williams, Robert W.; Holmes, Andrew

    2014-01-01

    Touchscreen-based systems are growing in popularity as a tractable, translational approach for studying learning and cognition in rodents. However, while mouse strains are well known to differ in learning across various settings, performance variation between strains in touchscreen learning has not been well described. The selection of appropriate genetic strains and backgrounds is critical to the design of touchscreen-based studies and provides a basis for elucidating genetic factors moderating behavior. Here we provide a quantitative foundation for visual discrimination and reversal learning using touchscreen assays across a total of 35 genotypes. We found significant differences in operant performance and learning, including faster reversal learning in DBA/2J compared to C57BL/6J mice. We then assessed DBA/2J and C57BL/6J for differential sensitivity to an environmental insult by testing for alterations in reversal learning following exposure to repeated swim stress. Stress facilitated reversal learning (selectively during the late stage of reversal) in C57BL/6J, but did not affect learning in DBA/2J. To dissect genetic factors underlying these differences, we phenotyped a family of 27 BXD strains generated by crossing C57BL/6J and DBA/2J. There was marked variation in discrimination, reversal and extinction learning across the BXD strains, suggesting this task may be useful for identifying underlying genetic differences. Moreover, different measures of touchscreen learning were only modestly correlated in the BXD strains, indicating that these processes are comparatively independent at both genetic and phenotypic levels. Finally, we examined the behavioral structure of learning via principal component analysis of the current data, plus an archival dataset, totaling 765 mice. This revealed 5 independent factors suggestive of “reversal learning,” “motivation-related late reversal learning,” “discrimination learning,” “speed to respond,” and

  18. 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).

  19. Surface strain measurements of fingertip skin under shearing

    PubMed Central

    2016-01-01

    The temporal evolution of surface strain, resulting from a combination of normal and tangential loading forces on the fingerpad, was calculated from high-resolution images. A customized robotic device loaded the fingertip with varying normal force, tangential direction and tangential speed. We observed strain waves that propagated from the periphery to the centre of the contact area. Consequently, different regions of the contact area were subject to varying degrees of compression, stretch and shear. The spatial distribution of both the strains and the strain energy densities depended on the stimulus direction. Additionally, the strains varied with the normal force level and were substantial, e.g. peak strains of 50% with a normal force of 5 N, i.e. at force levels well within the range of common dexterous manipulation tasks. While these observations were consistent with some theoretical predictions from contact mechanics, we also observed substantial deviations as expected given the complex geometry and mechanics of fingertips. Specifically, from in-depth analyses, we conclude that some of these deviations depend on local fingerprint patterns. Our data provide useful information for models of tactile afferent responses and background for the design of novel haptic interfaces. PMID:26888949

  20. Distinct phosphatase activity profiles in two strains of Trypanosoma cruzi.

    PubMed

    Morales-Neto, R; Hulshof, L; Ferreira, C V; Gadelha, F R

    2009-12-01

    Phosphorylation of parasite proteins plays a key role in the process of cell invasion by Trypanosoma cruzi, the etiologic agent of Chagas' disease. In this sense, characterization of parasite kinases and phosphatases could open new possibilities for the rational design of chemotherapeutic agents for the treatment of Chagas' disease. In this work, we analyzed phosphatase activities in T. cruzi homogenates from 2 strains belonging to different lineages and with different resistance to oxidative stress. Tulahuen 2 cells (Lineage I) showed higher phosphatase activities and specificity constants when compared to the Y strain (Lineage II). Tulahuen 2 had an optimum phosphatase activity at pH 4.0 and the Y strain at pH 7.0. In both cases, neutral–basic, but not acid, phosphatase activities were increased in the presence of Mg2+. Although calcium had an inhibitory effect at a pH of 7.0 and 8.0 in the Y strain, this inhibition was restricted to pH 8.0 in the other strain. Different substrates and acid phosphotyrosine and alkaline phosphatase inhibitors exhibited distinct effects on the phosphatase activity of both strains. Our results provide a better understanding of T. cruzi phosphatases and reinforce the notion of heterogeneity among T. cruzi populations.

  1. Effects of Applied Strain on Rates of Ageing: Project Overview

    NASA Technical Reports Server (NTRS)

    Campion, R. P.

    1997-01-01

    One of the stated intents of this project has been to make some assessment of effects of strain on rates of ageing of project thermoplastics exposed to project fluids. To this end, certain straining jigs which apply in various modes - tensile, four-point bending and crack growth using compact tension samples - were designed and made for holding samples during fluid exposures. During testing, features of the thermoplastics have been observed which have tended to confuse apparent strain effects on the polymers' aged performance, but recent assessments of the topic and its data have led to considerable progress being made in identifying test procedures necessary for strain and related effects on chemical deterioration to manifest themselves. It is the intent of this report to provide a summary of what has been determined on strain and related effects thus far, and provide recommendations for clarifying them in Phase 2 by means of further test procedures which will increase and focus the severity of the conditions applying. The choice of flexible pipe rather than umbilicals service for assessing service strain conditions reflects the major interest of project members. However, Tefzel data are still provided.

  2. WIPP Benchmark calculations with the large strain SPECTROM codes

    SciTech Connect

    Callahan, G.D.; DeVries, K.L.

    1995-08-01

    This report provides calculational results from the updated Lagrangian structural finite-element programs SPECTROM-32 and SPECTROM-333 for the purpose of qualifying these codes to perform analyses of structural situations in the Waste Isolation Pilot Plant (WIPP). Results are presented for the Second WIPP Benchmark (Benchmark II) Problems and for a simplified heated room problem used in a parallel design calculation study. The Benchmark II problems consist of an isothermal room problem and a heated room problem. The stratigraphy involves 27 distinct geologic layers including ten clay seams of which four are modeled as frictionless sliding interfaces. The analyses of the Benchmark II problems consider a 10-year simulation period. The evaluation of nine structural codes used in the Benchmark II problems shows that inclusion of finite-strain effects is not as significant as observed for the simplified heated room problem, and a variety of finite-strain and small-strain formulations produced similar results. The simplified heated room problem provides stratigraphic complexity equivalent to the Benchmark II problems but neglects sliding along the clay seams. The simplified heated problem does, however, provide a calculational check case where the small strain-formulation produced room closures about 20 percent greater than those obtained using finite-strain formulations. A discussion is given of each of the solved problems, and the computational results are compared with available published results. In general, the results of the two SPECTROM large strain codes compare favorably with results from other codes used to solve the problems.

  3. Structural analysis of strained quantum dots using nuclear magnetic resonance.

    PubMed

    Chekhovich, E A; Kavokin, K V; Puebla, J; Krysa, A B; Hopkinson, M; Andreev, A D; Sanchez, A M; Beanland, R; Skolnick, M S; Tartakovskii, A I

    2012-10-01

    Strained semiconductor nanostructures can be used to make single-photon sources, detectors and photovoltaic devices, and could potentially be used to create quantum logic devices. The development of such applications requires techniques capable of nanoscale structural analysis, but the microscopy methods typically used to analyse these materials are destructive. NMR techniques can provide non-invasive structural analysis, but have been restricted to strain-free semiconductor nanostructures because of the significant strain-induced quadrupole broadening of the NMR spectra. Here, we show that optically detected NMR spectroscopy can be used to analyse individual strained quantum dots. Our approach uses continuous-wave broadband radiofrequency excitation with a specially designed spectral pattern and can probe individual strained nanostructures containing only 1 × 10(5) quadrupole nuclear spins. With this technique, we are able to measure the strain distribution and chemical composition of quantum dots in the volume occupied by the single confined electron. The approach could also be used to address problems in quantum information processing such as the precise control of nuclear spins in the presence of strong quadrupole effects.

  4. Isolation and characterization of a new Arthrospira strain.

    PubMed

    de Morais, Michele Greque; da Cruz Reichert, Carolina; Dalcanton, Francieli; Durante, Andrei José; Marins, Luis Fernando; Costa, Jorge Alberto Vieira

    2008-01-01

    A filamentous microorganism, morphologically similar to the cyanobacterium Arthrospira, was isolated from Mangueira Lagoon in Brazil, from which Arthrospira has not previously been isolated. Random amplified polymorphic DNA (RAPD) comparison with the standard Arthrospira platensis strains LEB 52 and Paracas indicated that the organism isolated was an Arthrospira isolate, which we denominated strain LEB 18. The RAPD analysis showed conserved sequences which indicated that the three strains belonged to the same genus, and were all Arthrospira species, but there were sufficient differences between them suggesting that they were separate strains. The strain LEB 18 was cultivated in undiluted Zarrouk medium and in 60% and 20% (v/v) Zarrouk medium diluted with sterilized Mangueira Lagoon water (MLW) using illuminance rates of 32.5, 45.5 and 58.5 micromol m(-2) s(-1) according to a complete 32 factorial design with a triplicate central point. The strains LEB 52 and Paracas were cultived in the conditions central point. Our new isolate produced the highest specific growth rate (Umax = 0.22 d(-1)) in 60% Zarrouk medium diluted with MLW and illuminated with 58.5 micromol m(-2) s(-1) and the highest protein content (86.0% w/w).

  5. Peri-Implant Strain in an In Vitro Model.

    PubMed

    Hussaini, Souheil; Vaidyanathan, Tritala K; Wadkar, Abhinav P; Quran, Firas A Al; Ehrenberg, David; Weiner, Saul

    2015-10-01

    An in vitro experimental model was designed and tested to determine the influence that peri-implant strain may have on the overall crestal bone. Strain gages were attached to polymethylmethacrylate (PMMA) models containing a screw-type root form implant at sites 1 mm from the resin-implant interface. Three different types of crown superstructures (cemented, 1-screw [UCLA] and 2-screw abutment types) were tested. Loading (1 Hz, 200 N load) was performed using a MTS Mechanical Test System. The strain gage data were stored and organized in a computer for statistical treatment. Strains for all abutment types did not exceed the physiological range for modeling and remodeling of cancellous bone, 200-2500 με (microstrain). For approximately one-quarter of the trials, the strain values were less than 200 με the zone for bone atrophy. The mean microstrain obtained was 517.7 με. In conclusion, the peri-implant strain in this in vitro model did not exceed the physiologic range of bone remodeling under axial occlusal loading.

  6. Measuring mine roof bolt strains

    DOEpatents

    Steblay, Bernard J.

    1986-01-01

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

  7. Tuning magnetism by biaxial strain in native ZnO.

    PubMed

    Peng, Chengxiao; Wang, Yuanxu; Cheng, Zhenxiang; Zhang, Guangbiao; Wang, Chao; Yang, Gui

    2015-07-07

    Magnetic ZnO, one of the most important diluted magnetic semiconductors (DMS), has attracted great scientific interest because of its possible technological applications in optomagnetic devices. Magnetism in this material is usually delicately tuned by the doping level, dislocations, and local structures. The rational control of magnetism in ZnO is a highly attractive approach for practical applications. Here, the tuning effect of biaxial strain on the d(0) magnetism of native imperfect ZnO is demonstrated through first-principles calculations. Our calculation results show that strain conditions have little effect on the defect formation energy of Zn and O vacancies in ZnO, but they do affect the magnetism significantly. For a cation vacancy, increasing the compressive strain will obviously decrease its magnetic moment, while tensile strain cannot change the moment, which remains constant at 2 μB. For a singly charged anion vacancy, however, the dependence of the magnetic moment on strain is opposite to that of the Zn vacancy. Furthermore, the ferromagnetic state is always present, irrespective of the strain type, for ZnO with two zinc vacancies, 2VZns. A large tensile strain is favorable for improving the Curie temperature and realizing room temperature ferromagnetism for ZnO-based native semiconductors. For ZnO with two singly charged oxygen vacancies, 2Vs, no ferromagnetic ordering can be observed. Our work points the way to the rational design of materials beyond ZnO with novel non-intrinsic functionality by simply tuning the strain in a thin film form.

  8. Suppression of Low Strain Rate Nonpremixed Flames by an Agent

    NASA Technical Reports Server (NTRS)

    Olson, Sandra L. (Technical Monitor); Hamins, A.; Bundy, M.; Oh, C. B.; Park, J.; Puri, I. K.

    2004-01-01

    The extinction and structure of non-premixed methane/air flames were investigated in normal gravity and microgravity through the comparison of experiments and calculations using a counterflow configuration. From a fire safety perspective, low strain rate conditions are important for several reasons. In normal gravity, many fires start from small ignition sources where the convective flow and strain rates are weak. Fires in microgravity conditions, such as a manned spacecraft, may also occur in near quiescent conditions where strain rates are very low. When designing a fire suppression system, worst-case conditions should be considered. Most diffusion flames become more robust as the strain rate is decreased. The goal of this project is to investigate the extinction limits of non-premixed flames using various agents and to compare reduced gravity and normal gravity conditions. Experiments at the NASA Glenn Research Center's 2.2-second drop tower were conducted to attain extinction and temperature measurements in low-strain non-premixed flames. Extinction measurements using nitrogen added to the fuel stream were performed for global strain rates from 7/s to 50/s. The results confirmed the "turning point" behavior observed previously by Maruta et al. in a 10 s drop tower. The maximum nitrogen volume fraction in the fuel stream needed to assure extinction for all strain rates was measured to be 0.855+/-0.016, associated with the turning point determined to occur at a strain rate of 15/s. The critical nitrogen volume fraction in the fuel stream needed for extinction of 0-g flames was measured to be higher than that of 1-g flames.

  9. Eccentric exercise in vivo: strain-induced muscle damage and adaptation in a stable system.

    PubMed

    Butterfield, Timothy A

    2010-04-01

    The muscle tendon unit is a stable system, designed to operate eccentrically with efficiency and resiliency. Fiber strains, although minimized by tendon compliance during exercise, are essential components to decoding the mechanical and chemical signals during exercise. Subsequent cellular adaptations minimize the subsequent "dose" of stress and strain and serve to limit the exacerbation of damage into injury.

  10. Psychological Strain and Emotional Labor among Police-Officers: A Diary Study

    ERIC Educational Resources Information Center

    van Gelderen, Benjamin; Heuven, Ellen; van Veldhoven, Marc; Zeelenberg, Marcel; Croon, Marcel

    2007-01-01

    The authors examined the relationship between psychological strain, emotional dissonance and emotional job demands during a working day of 65 Dutch (military) police officers, using a 5-day diary design. We hypothesized that emotional dissonance partly mediated the relationship between psychological strain at the start and at the end of a work…

  11. Rapid detection of methicillin-resistant Staphylococcus aureus strains not identified by slide agglutination tests.

    PubMed Central

    Kuusela, P; Hildén, P; Savolainen, K; Vuento, M; Lyytikäinen, O; Vuopio-Varkila, J

    1994-01-01

    Seventy-nine methicillin-resistant Staphylococcus aureus (MRSA) strains, isolated during 1980 to 1990, were classified as MRSA Aggl- (14 strains) and MRSA Aggl+ (65 strains) strains on the basis of test results in slide agglutination assays designed to detect fibrinogen-binding protein (clumping factor) and protein A on the staphylococcal surface. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that lysostaphin digests of MRSA Aggl- strains contained a high-molecular-weight protein which was not detected in digests of MRSA Aggl+ strains. Immunization of rabbits with an MRSA Aggl- strain produced an antiserum which agglutinated all MRSA Aggl- strains and also 64 of 65 MRSA Aggl+ strains. Only 1 of 68 coagulase-negative staphylococci showed agglutination in this assay. The anti-MRSA Aggl- antiserum reacted mainly with a 230-kDa staphylococcal surface protein but also with a 175-kDa protein, probably formed by proteolysis of the former and a few slightly smaller proteins. These could not be immunologically detected in lysostaphin digests of MRSA Aggl+ strains. Purified antibodies reacting with the 230-kDa protein agglutinated all MRSA Aggl- strains, indicating that the protein is located on the surfaces of staphylococci. The results suggest a tentative role for the 230-kDa protein or its fragments as a novel target to develop more efficient rapid identification methods for S. aureus, including MRSA. Images PMID:8126170

  12. C55 bacteriocin produced by ETB-plasmid positive Staphylococcus aureus strains is a key factor for competition with S. aureus strains.

    PubMed

    Kawada-Matsuo, Miki; Shammi, Fariha; Oogai, Yuichi; Nakamura, Norifumi; Sugai, Motoyuki; Komatsuzawa, Hitoshi

    2016-03-01

    Exfoliative toxin (ET) produced by Staphylococcus aureus is closely associated with the onset of bullous impetigo. To date, three ETs (ETA, ETB and ETD) have been identified. The gene encoding ETB is located in a plasmid designated pETB. Bacteriocin synthesis genes are also located in this plasmid and pETB-positive strains reportedly produce the C55 bacteriocin. In this study, the antibacterial activity against S. aureus strains of the bacteriocin produced by the pETB-positive strain TY4 was investigated. This bacteriocin demonstrated antibacterial activity against all pETB-negative but not pETB-positive strains, including TY4. Additionally, a TY4- strain from which the pETB plasmid had been deleted exhibited susceptibility to the bacteriocin. Further experiments revealed that two immunity factors (orf 46-47 and orf 48) downstream of the bacteriocin synthesis genes in the pETB plasmid are associated with immunity against the bacteriocin produced by TY4. The TY4- with orf46-47 strain exhibited complete resistance to bacteriocin, whereas the TY4- with orf48 strain exhibited partial resistance. Whether bacteriocin affects the proportion of each strain when co-cultured with S. aureus strains was also investigated. When TY4 or TY4- was co-cultured with 209P strain, which is susceptible to the bacteriocin, the proportion of 209P co-cultured with TY4 was significantly less than when 209P was co-cultured with TY4-, whereas the proportion of TY4- with orf46-48 co-cultured with TY4 was greater than with TY4-. These results suggest that the C55 bacteriocin produced by pETB-positive strains affects the proportion of each strain when pETB-positive and -negative strains co-exist.

  13. Effect of Local Tidal Lung Strain on Inflammation in Normal and Lipopolysaccharide-Exposed Sheep

    PubMed Central

    Wellman, Tyler J.; Winkler, Tilo; Costa, Eduardo L.V.; Musch, Guido; Harris, R. Scott; Zheng, Hui; Venegas, Jose G.; Vidal Melo, Marcos F.

    2014-01-01

    Objective Regional tidal lung strain may trigger local inflammation during mechanical ventilation, particularly when additional inflammatory stimuli are present. However, it is unclear whether inflammation develops proportionally to tidal strain or only above a threshold. We aimed to: (1) assess the relationship between regional tidal strain and local inflammation in vivo during the early stages of lung injury in lungs with regional aeration heterogeneity comparable to that of humans; and (2) determine how this strain-inflammation relationship is affected by endotoxemia. Design Interventional animal study. Setting Experimental laboratory and positron emission tomography (PET) facility. Subjects Eighteen 2–4-month-old sheep. Interventions Three groups of sheep (n=6) were mechanically ventilated to the same plateau pressure (30–32 cmH2O) with High-Strain (VT=18.2±6.5 ml/kg, PEEP=0), High-Strain plus intravenous lipopolysaccharide (LPS) (VT=18.4±4.2 ml/kg, PEEP=0), or Low-Strain plus LPS (VT=8.1±0.2 ml/kg, PEEP=17±3 cmH2O). At baseline, we acquired respiratory-gated PET scans of inhaled 13NN to measure tidal strain from end-expiratory and end-inspiratory images in six regions of interest (ROIs). After 3 hours of mechanical ventilation, dynamic [18F]fluoro-2-deoxy-D-glucose (18F-FDG) scans were acquired to quantify metabolic activation, indicating local neutrophilic inflammation, in the same ROIs. Measurements and Main Results Baseline regional tidal strain had a significant effect on 18F-FDG net uptake rate Ki in High-Strain LPS (p=0.036) and on phosphorylation rate k3 in High-Strain (p=0.027) and High-Strain LPS (p=0.004). LPS exposure increased the k3-tidal strain slope 3-fold (p=0.009), without significant lung edema. The Low-Strain LPS group showed lower baseline regional tidal strain (0.33±0.17) than High-Strain (1.21±0.62; p<0.001) or High-Strain LPS (1.26±0.44; p<0.001), and lower k3 (p<0.001) and Ki (p<0.05) than High-Strain LPS. Conclusions Local

  14. 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.

  15. 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

  16. Asymmetrically doped stacked channel strained SOI FinFET

    NASA Astrophysics Data System (ADS)

    Dubey, Shashank; Kondekar, Pravin N.

    2017-02-01

    Strained SOI (SSOI) n-channel trigate FinFET is designed with asymmetrically doped stacked channels along the fin height. The OFF current is reduced with respect to lightly doped uniform SSOI FinFET because of band gap modification, originated between highly doped uniaxial strained and lightly doped Si fin. Through TCAD simulation it is observed that for the stacked devices the OFF current is reduced by more than 47%. The performances are also compared with highly doped uniform SSOI FinFETs and the results indicated that these devices have lesser random dopant variation at a moderate cost of ON and OFF current.

  17. Strain-controlled thermal conductivity in ferroic twinned films

    PubMed Central

    Li, Suzhi; Ding, Xiangdong; Ren, Jie; Moya, Xavier; Li, Ju; Sun, Jun; Salje, Ekhard K. H.

    2014-01-01

    Large reversible changes of thermal conductivity are induced by mechanical stress, and the corresponding device is a key element for phononics applications. We show that the thermal conductivity κ of ferroic twinned thin films can be reversibly controlled by strain. Nonequilibrium molecular dynamics simulations reveal that thermal conductivity decreases linearly with the number of twin boundaries perpendicular to the direction of heat flow. Our demonstration of large and reversible changes in thermal conductivity driven by strain may inspire the design of controllable thermal switches for thermal logic gates and all-solid-state cooling devices. PMID:25224749

  18. High strain-rate model for fiber-reinforced composites

    SciTech Connect

    Aidun, J.B.; Addessio, F.L.

    1995-07-01

    Numerical simulations of dynamic uniaxial strain loading of fiber-reinforced composites are presented that illustrate the wide range of deformation mechanisms that can be captured using a micromechanics-based homogenization technique as the material model in existing continuum mechanics computer programs. Enhancements to the material model incorporate high strain-rate plastic response, elastic nonlinearity, and rate-dependent strength degradation due to material damage, fiber debonding, and delamination. These make the model relevant to designing composite structural components for crash safety, armor, and munitions applications.

  19. Mapping of IS6110 Insertion Sites in Two Epidemic Strains of Mycobacterium tuberculosis

    PubMed Central

    Beggs, Marjorie L.; Eisenach, Kathleen D.; Cave, M. Donald

    2000-01-01

    A widely distributed strain designated 210 was identified in a study of the diversity of Mycobacterium tuberculosis DNA fingerprints from three geographically separate states in the United States. This strain is characterized by a 21-band fingerprint pattern when probed with IS6110, and the pattern is similar to that displayed by strains designated W. Intracellular growth of strain 210 isolates in human macrophages is significantly faster than that of isolates from other clusters or nonclustered isolates. The purpose of this study was to identify the sites of IS6110 insertions in strain 210 and compare these to IS6110 insertion sites in strain W. Our hypothesis is that an IS6110 insertion site(s) could possibly be responsible for a strain's increased capacity for transmission and/or replication. In this report, the insertion sites in strains 210 and W are described and referenced to their location in the M. tuberculosis H37Rv genome sequence. The W and 210 strains have 17 identical sites of IS6110 insertion and additional sequence not found in H37Rv but present in other clinical isolates. The IS6110 insertion site in the 36-bp direct repeat (DR) region of strains 210 and W has 15 spacers in the left flanking region. The DR region on the right side of IS6110 has been deleted. Five sites of insertion in strain 210 not found in strain W are described, as well as two unique sites in strain W. One copy of IS6110 was found to reside 55 bp in the ctpD gene. This gene is expressed, indicating that IS6110 can provide a promoter sequence for the transcription of genes. PMID:10921952

  20. 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

  1. 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)

  2. 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...

  3. 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

  4. Draft Genome Sequence of the Field Isolate Brucella melitensis Strain Bm IND1 from India.

    PubMed

    Rao, Sashi Bhushan; Gupta, Vivek K; Kumar, Mukesh; Hegde, Nagendra R; Splitter, Gary A; Reddanna, Pallu; Radhakrishnan, Girish K

    2014-05-29

    Brucella spp. are facultative intracellular bacterial pathogens causing the zoonotic disease brucellosis. Here, we report the draft genome sequence of the Brucella melitensis strain from India designated Bm IND1, isolated from stomach contents of an aborted goat fetus.

  5. Internal strain, deformation, and failure of large scale pullout tests in concrete

    NASA Astrophysics Data System (ADS)

    Stone, W. C.

    1982-05-01

    Detailed experimental data on crack propagation and internal strain distribution for the pullout test is presented. A 12:1 scaled-up pullout test was designed, using a commercial pullout insert for the prototype dimensions, and was instrumented with small waterproof embedment strain gages so as to obtain internal strain profiles at critical locations. Two large scale specimens were tested with apex angles falling at the upper and lower bounds currently recommended in ASTM C-900. Two dimensional axisymmetric finite element analyses were performed for the two experimental specimens and the results were compared with measured strains for load stages below the onset of internal cracking.

  6. High compressive pre-strains reduce the bending fatigue life of nitinol wire.

    PubMed

    Gupta, Shikha; Pelton, Alan R; Weaver, Jason D; Gong, Xiao-Yan; Nagaraja, Srinidhi

    2015-04-01

    initiated from surface inclusions in nearly all wires. Compressive pre-strain-induced damage may accelerate such crack initiation, thereby reducing fatigue life. The results of the present study indicate that large compressive pre-strains are detrimental to the fatigue properties of Nitinol, and, taken together, the findings underscore the importance of accounting for thermo-mechanical history in the design and testing of wire-based percutaneous implants.

  7. Discrete shaped strain sensors for intelligent structures

    NASA Technical Reports Server (NTRS)

    Andersson, Mark S.; Crawley, Edward F.

    1992-01-01

    Design of discrete, highly distributed sensor systems for intelligent structures has been studied. Data obtained indicate that discrete strain-averaging sensors satisfy the functional requirements for distributed sensing of intelligent structures. Bartlett and Gauss-Hanning sensors, in particular, provide good wavenumber characteristics while meeting the functional requirements. They are characterized by good rolloff rates and positive Fourier transforms for all wavenumbers. For the numerical integration schemes, Simpson's rule is considered to be very simple to implement and consistently provides accurate results for five sensors or more. It is shown that a sensor system that satisfies the functional requirements can be applied to a structure that supports mode shapes with purely sinusoidal curvature.

  8. Indices of Psychological Strain During Hypoxis Bedrest

    NASA Astrophysics Data System (ADS)

    Stavrou, Nektarios A.; McDonnell, Adam C.; Eiken, Ola; Mekjavic, Igor B.

    2013-02-01

    Much attention has been devoted to the physiological changes that occur during bed rest. However, there has been a lack of focus on the psychological aspects per se. We investigated indices of psychological strain during three 10-d interventions, designed to assess the combined effects of inactivity/unloading and normobaric hypoxia on several physiological systems. Eleven male participants underwent three 10-d campaigns in a randomized manner: 1) normobaric hypoxic ambulatory confinement (HAMB), 2) normobaric hypoxic bed rest (HBR) and 3) normoxic bed rest (NBR). The most negative psychological profile appeared on BR10 of HBR and HAmb conditions (hypoxic conditions). Concomitantly a decrease in positive emotions was observed from BR-2 to BR10. Bed rest and exposure to hypoxic environments seems to exert a negative effect on person’s psychological mood.

  9. Effects of strain rate, mixing ratio, and stress-strain definition on the mechanical behavior of the polydimethylsiloxane (PDMS) material as related to its biological applications.

    PubMed

    Khanafer, Khalil; Duprey, Ambroise; Schlicht, Marty; Berguer, Ramon

    2009-04-01

    Tensile tests on Polydimethylsiloxane (PDMS) materials were conducted to illustrate the effects of mixing ratio, definition of the stress-strain curve, and the strain rate on the elastic modulus and stress-strain curve. PDMS specimens were prepared according to the ASTM standards for elastic materials. Our results indicate that the physiological elastic modulus depends strongly on the definition of the stress-strain curve, mixing ratio, and the strain rate. For various mixing ratios and strain rates, true stress-strain definition results in higher stress and elastic modulus compared with engineering stress-strain and true stress-engineering strain definitions. The elastic modulus increases as the mixing ratio increases up-to 9:1 ratio after which the elastic modulus begins to decrease even as the mixing ratio continues to increase. The results presented in this study will be helpful to assist the design of in vitro experiments to mimic blood flow in arteries and to understand the complex interaction between blood flow and the walls of arteries using PDMS elastomer.

  10. 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.

  11. 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.

  12. Strain Localization in an Oscillating Maxwell Viscoelastic Cylinder.

    PubMed

    Massouros, Panagiotis G; Bayly, Philip V; Genin, Guy M

    2014-01-15

    The transient rotation responses of simple, axisymmetric, viscoelastic structures are of interest for interpretation of experiments designed to characterize materials and closed structures such as the brain using magnetic resonance techniques. Here, we studied the response of a Maxwell viscoelastic cylinder to small, sinusoidal displacement of its outer boundary. The transient strain field can be calculated in closed form using any of several conventional approaches. The solution is surprising: the strain field develops a singularity that appears when the wavefront leaves the center of the cylinder, and persists as the wavefront reflects to the outer boundary and back to the center of the cylinder. The singularity is alternately annihilated and reinitiated upon subsequent departures of the wavefront from the center of the cylinder until it disappears in the limit of steady state oscillations. We present the solution for this strain field, characterize the nature of this singularity, and discuss its potential role in the mechanical response and evolved morphology of the brain.

  13. Evaluation of Strain Measurement Devices for Inflatable Structures

    NASA Technical Reports Server (NTRS)

    Litteken, Douglas A.

    2017-01-01

    Inflatable structures provide a significant volume savings for future NASA deep space missions. The complexity of these structures, however, provides difficulty for engineers in designing, analyzing, and testing. Common strain measurement systems for metallic parts cannot be used directly on fabrics. New technologies must be developed and tested to accuractly measure the strain of inflatable structures. This paper documents the testing of six candidate strain measurement devices for use on fabrics. The resistance devices tested showed significant hysteresis during creep and cyclic testing. The capacitive device, however, showed excellent results and little-to-no hysteresis. Because of this issue, only two out of the six proposed devices will continue in development. The resulting data and lessons learned from this effort provides direction for continued work to produce a structural health monitoring system for inflatable habitats.

  14. Biotransformation of Tributyltin chloride by Pseudomonas stutzeri strain DN2

    PubMed Central

    Khanolkar, Dnyanada S.; Naik, Milind Mohan; Dubey, Santosh Kumar

    2014-01-01

    A bacterial isolate capable of utilizing tributyltin chloride (TBTCl) as sole carbon source was isolated from estuarine sediments of west coast of India and identified as Pseudomonas stutzeri based on biochemical tests and Fatty acid methyl ester (FAME) analysis. This isolate was designated as strain DN2. Although this bacterial isolate could resist up to 3 mM TBTCl level, it showed maximum growth at 2 mM TBTCl in mineral salt medium (MSM). Pseudomonas stutzeri DN2 exposed to 2 mM TBTCl revealed significant alteration in cell morphology as elongation and shrinkage in cell size along with roughness of cell surface. FTIR and NMR analysis of TBTCl degradation product extracted using chloroform and purified using column chromatography clearly revealed biotransformation of TBTCl into Dibutyltin dichloride (DBTCl2) through debutylation process. Therefore, Pseudomonas stutzeri strain DN2 may be used as a potential bacterial strain for bioremediation of TBTCl contaminated aquatic environmental sites. PMID:25763027

  15. Evaluation of Strain Measurement Devices for Inflatable Structures

    NASA Technical Reports Server (NTRS)

    Litteken, Doug

    2017-01-01

    Inflatable structures provide a significant volume savings for future NASA deep space missions. The complexity of these structures, however, provides difficulty for engineers in designing, analyzing, and testing. Common strain measurement systems for metallic parts cannot be used directly on fabrics. New technologies must be developed and tested to accurately measure the strain of inflatable structures. This paper documents the testing of six candidate strain measurement devices for use on fabrics. The resistance devices tested showed significant hysteresis during creep and cyclic testing. The capacitive device, however, showed excellent results and little-to-no hysteresis. Because of this issue, only two out of the six proposed devices will continue in development. The resulting data and lessons learned from this effort provides direction for continued work to produce a structural health monitoring system for inflatable habitats.

  16. Genetic and phenotypic characterization of a Japanese wild-derived DOB/Oda rat strain.

    PubMed

    Kuramoto, Takashi; Inoue, Satoko; Neoda, Yuki; Yamasaki, Ken-ichi; Hashimoto, Ryoko; Mashimo, Tomoji; Oda, Sen-ichi; Serikawa, Tadao

    2013-08-01

    Wild-derived rat strains can provide novel genome resources that are not available in standard laboratory strains. Genetic backgrounds of wild-derived strains can facilitate effective genetic linkage analyses and often modulate the expression of mutant phenotypes. Here we describe the development and characterization of a new inbred rat strain, DOB/Oda, from wild rats (Rattus norvegicus) captured in Shitara, Aichi, Japan. Phenotype analysis of 109 parameters revealed that the DOB/Oda rats had small body weight, preference for darkness, and high locomotor activity compared with the rat strains in the National BioResource Project for the Rat (NBRP-Rat) database. Genome analysis with 357 SSLP markers identified DOB/Oda-specific alleles in 70 markers. The percentage of SSLP markers that showed polymorphism between the DOB/Oda strain and any of 132 laboratory strains from NBRP-Rat varied from 89 to 95 %. The polymorphic rate (average of the values of the percentage) for the DOB/Oda strain was 91.6 %, much higher than the rates for available wild-derived strains such as the Brown Norway rat. A phylogenic tree constructed with DOB/Oda and all the strains in NBRP-Rat showed that the DOB/Oda strain localized within the wild rat groups, apparently separate from the laboratory strains. Together, these findings indicated that the DOB/Oda rat has a unique genome that is not available in the laboratory strains. Therefore, the new DOB/Oda strain will provide an important genome resource that will be useful for designing genetic experiments and for the discovery of genes that modulate mutant phenotypes.

  17. Anisotropic strain dependence of oxygen vacancy formation in YBa2Cu3O7-δ: first principle study

    NASA Astrophysics Data System (ADS)

    Horide, Tomoya; Matsumoto, Kaname

    2014-11-01

    Anisotropic strain dependence of oxygen vacancy(OV) formation energy(Evac) was clarified in YBa2Cu3O7 using first principle calculation. Evac decreased with increase in tensile strain, and the effect strongly depended on crystallographic direction of strain. Anisotropy in strain dependence of Evac originated from variation of hybridization peak structure and significant atomic relaxation of Cu, which resulted from anisotropic bonding of CuO chain. Evac was small in the c-axis and b-axis in tensile strain case, showing that OV concentration was increased significantly by the c-axis and b-axis tensile strain. For OV suppression, elastic strain and lattice defects should be designed so as to decrease c-axis and b-axis tensile strain.

  18. Strain compensation in a semiconducting device structure using an intentionally mismatched uniform buffer layer

    NASA Astrophysics Data System (ADS)

    Kujofsa, Tedi; Ayers, John E.

    2016-12-01

    The extent of strain relaxation in semiconducting device heterostructures has important implications in the design of high electron mobility transistors, light-emitting diodes, and laser diodes, in which the residual strain affects the device characteristics. In this work, we develop the theoretical framework for understanding strain compensation in a semiconductor device layer using a uniform buffer layer which can be intentionally mismatched to the material above. Specifically, we determined the critical condition for complete strain compensation in the device layer by intentionally introducing a compositional mismatch at the device-buffer interface. We present minimum energy calculations and show that for a given device layer with fixed mismatch and layer thickness, the buffer layer may be designed with the appropriate combination of thickness and mismatch such that the device layer will have zero residual strain in equilibrium. Such a structure can be referred to as a completely strain-compensated design. In the more general case, there may be partial strain compensation, and we give a simple physics-based Gaussian-type function describing the residual strain in the device layer. We have applied this general framework to In x Ga1-x As/GaAs (001) heterostructures for the purpose of illustration, but the work is applicable to any diamond or zinc blende (001) heteroepitaxial material system.

  19. 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 ...

  20. Utilizing Photogrammetry and Strain Gage Measurement to Characterize Pressurization of Inflatable Modules

    NASA Technical Reports Server (NTRS)

    Mohammed, Anil

    2011-01-01

    This paper focuses on integrating a large hatch penetration into inflatable modules of various constructions. This paper also compares load predictions with test measurements. The strain was measured by utilizing photogrammetric methods and strain gages mounted to select clevises that interface with the structural webbings. Bench testing showed good correlation between strain data collected from an extensometer and photogrammetric measurements, even when the material transitioned from the low load to high load strain region of the curve. The full-scale torus design module showed mixed results as well in the lower load and high strain regions. After thorough analysis of photogrammetric measurements, strain gage measurements, and predicted load, the photogrammetric measurements seem to be off by a factor of two.

  1. Thermoresistive strain sensor and positioning method for roll-to-roll processes.

    PubMed

    Liao, Kuan-Hsun; Lo, Cheng-Yao

    2014-05-05

    This study uses the Joule heating effect-generated temperature difference to monitor in real-time and localize both compressive and tensile strains for the polymer substrates used in the roll-to-roll process. A serpentine gold (Au) line was patterned on a polyethylenenaphthalate (PEN) substrate to form the strain sensor based on thermoresistive behavior. This strain sensor was then subjected to either current or voltage to induce the Joule heating effect on the Au resistor. An infrared (IR) detector was used to monitor the strain-induced temperature difference on the Au and PEN surfaces and the minimal detectable bending radius was 0.9 mm with a gauge factor (GF) of 1.46. The proposed design eliminates the judgment ambiguity from conventional resistive strain sensors where resistance is the only physical quantity monitored. This study precisely and successfully indicated the local strain quantitatively and qualitatively with complete simulations and measurements.

  2. Realization of nano static strain sensing with fiber Bragg gratings interrogated by narrow linewidth tunable lasers.

    PubMed

    Liu, Qingwen; Tokunaga, Tomochika; He, Zuyuan

    2011-10-10

    Aiming at realizing a static strain sensor of nano-strain resolution, which is required in most geophysical applications, this paper presents a thorough analysis on the strain resolution of a fiber Bragg grating (FBG) static strain sensor interrogated with a narrow linewidth tunable laser. The main noise sources of the sensor are discussed, and the strain resolution is deduced with a cross-correlation algorithm. The theoretical prediction agrees well with our experimental result, and the analysis is further validated by numerical simulations. Based on the analysis, the paper provides the guidelines for optimizing this type of sensor to realize ultra-high resolution. It is shown that with properly designed FBGs and interrogation systems, nano static strain resolution can be realized, as we recently demonstrated in experiment.

  3. Deformation-induced spatiotemporal fluctuation, evolution and localization of strain fields in a bulk metallic glass

    DOE PAGES

    Wu, Yuan; Bei, Hongbin; Wang, Yanli; ...

    2015-05-16

    Deformation behavior and local strain evolutions upon loading and unloading of a bulk metallic glass (BMG) were systematically investigated by in situ digital image correlation (DIC). Distinct fluctuations and irreversible local strains were observed before the onset of macroscopic yielding. Statistical analysis shows that these fluctuations might be related to intrinsic structural heterogeneities, and that the evolution history and characteristics of local strain fields play an important role in the subsequent initiation of shear bands. Effects of sample size, pre-strain, and loading conditions were systematically analyzed in terms of the probability distributions of the resulting local strain fields. It ismore » found that a higher degree of local shear strain heterogeneity corresponds to a more ductile stressestrain curve. Implications of these findings are discussed for the design of new materials.« less

  4. Deformation-induced spatiotemporal fluctuation, evolution and localization of strain fields in a bulk metallic glass

    SciTech Connect

    Wu, Yuan; Bei, Hongbin; Wang, Yanli; Lu, Zhaoping; George, Easo P.; Gao, Yanfei

    2015-05-16

    Deformation behavior and local strain evolutions upon loading and unloading of a bulk metallic glass (BMG) were systematically investigated by in situ digital image correlation (DIC). Distinct fluctuations and irreversible local strains were observed before the onset of macroscopic yielding. Statistical analysis shows that these fluctuations might be related to intrinsic structural heterogeneities, and that the evolution history and characteristics of local strain fields play an important role in the subsequent initiation of shear bands. Effects of sample size, pre-strain, and loading conditions were systematically analyzed in terms of the probability distributions of the resulting local strain fields. It is found that a higher degree of local shear strain heterogeneity corresponds to a more ductile stressestrain curve. Implications of these findings are discussed for the design of new materials.

  5. Recommended Strain Gage Application Procedures for Various Langley Research Center Balances and Test Articles

    NASA Technical Reports Server (NTRS)

    Moore, Thomas C., Sr.

    1997-01-01

    The NASA Langley Research Center uses more than 10000 strain gages per year in supporting its various research programs. The character of the testing at LaRC is such that the types of strain gage installations, the materials they are applied to, and the test environments encountered, require many varied approaches for installing strain gages. These installations must be accomplished in the most technically discerning and appropriate manner. This technical memorandum is offered as an assisting guide in helping the strain gage user to determine the appropriate approach for a given strain gage application requirement. Specifically, this document offers detailed recommendations for strain gaging the following: LaRC-Designed balances, LARC custom transducers, certain composite materials and alloys, high-temperature test articles, and selected non-typical or unique materials or test conditions.

  6. Thermoresistive Strain Sensor and Positioning Method for Roll-to-Roll Processes

    PubMed Central

    Liao, Kuan-Hsun; Lo, Cheng-Yao

    2014-01-01

    This study uses the Joule heating effect-generated temperature difference to monitor in real-time and localize both compressive and tensile strains for the polymer substrates used in the roll-to-roll process. A serpentine gold (Au) line was patterned on a polyethylenenaphthalate (PEN) substrate to form the strain sensor based on thermoresistive behavior. This strain sensor was then subjected to either current or voltage to induce the Joule heating effect on the Au resistor. An infrared (IR) detector was used to monitor the strain-induced temperature difference on the Au and PEN surfaces and the minimal detectable bending radius was 0.9 mm with a gauge factor (GF) of 1.46. The proposed design eliminates the judgment ambiguity from conventional resistive strain sensors where resistance is the only physical quantity monitored. This study precisely and successfully indicated the local strain quantitatively and qualitatively with complete simulations and measurements. PMID:24803196

  7. Nonlinear strain dependences in highly strained germanium micromembranes for on-chip light source applications (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Guilloy, Kevin; Gassenq, Alban; Pauc, Nicolas; Escalante Fernandez, Jose Maria; Duchemin, Ivan; Niquet, Yann-Michel; Tardif, Samuel; Rieutord, Francois; Gentile, Pascal; Osvaldo Dias, Guilherme; Rouchon, Denis; Widiez, Julie; Hartmann, Jean-Michel; Fowler, Daivid; Chelnokov, Alexei; Geiger, Richard; Zabel, Thomas; Sigg, Hans C.; Faist, Jérôme; Reboud, Vincent; Calvo, Vincent

    2016-05-01

    ]. Finally, we performed electro-absorption measurements on micro-membranes to determine the energy of the direct transitions (conduction band to light and heavy holes) in uniaxially stressed germanium. The relationship between strain and direct bandgap became nonlinear above 2.5 %, in agreement with our theoretical models. In conclusion, we show that under uniaxial strain level above 2 %, germanium exhibits significant nonlinear behaviors which have to be taken into consideration for the design and fabrication of future on-chip germanium laser sources compatible with CMOS technologies. [1] Van de Walle, Phys. Rev. B 39, 1871 (1989) [2] Lim et al., Opt. Express 17, 16358 (2009) [3] Süess et al., Nature Phot. 7, 466 (2013) [4] Widiez et al., ECS Transaction 64, 35-48 (2014) [5] Gassenq et al., submitted [6] Gassenq et al., submitted

  8. 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

  9. Fabric strain sensor integrated with CNPECs for repeated large deformation

    NASA Astrophysics Data System (ADS)

    Yi, Weijing

    Flexible and soft strain sensors that can be used in smart textiles for wearable applications are much desired. They should meet the requirements of low modulus, large working range and good fatigue resistance as well as good sensing performances. However, there were no commercial products available and the objective of the thesis is to investigate fabric strain sensors based on carbon nanoparticle (CNP) filled elastomer composites (CNPECs) for potential wearing applications. Conductive CNPECs were fabricated and investigated. The introduction of silicone oil (SO) significantly decreased modulus of the composites to less than 1 MPa without affecting their deformability and they showed good stability after heat treatment. With increase of CNP concentration, a percolation appeared in electrical resistivity and the composites can be divided into three ranges. I-V curves and impedance spectra together with electro-mechanical studies demonstrated a balance between sensitivity and working range for the composites with CNP concentrations in post percolation range, and were preferred for sensing applications only if the fatigue life was improved. Due to the good elasticity and failure resist property of knitted fabric under repeated extension, it was adopted as substrate to increase the fatigue life of the conductive composites. After optimization of processing parameters, the conductive fabric with CNP concentration of 9.0CNP showed linear I-V curves when voltage is in the range of -1 V/mm and 1 V/mm and negligible capacitive behavior when frequency below 103 Hz even with strain of 60%. It showed higher sensitivity due to the combination of nonlinear resistance-strain behavior of the CNPECs and non-even strain distribution of knitted fabric under extension. The fatigue life of the conductive fabric was greatly improved. Extended on the studies of CNPECs and the coated conductive fabrics, a fabric strain sensor was designed, fabricated and packaged. The Young's modulus of

  10. Strain transfer analysis of optical fiber based sensors embedded in an asphalt pavement structure

    NASA Astrophysics Data System (ADS)

    Wang, Huaping; Xiang, Ping

    2016-07-01

    Asphalt pavement is vulnerable to random damage, such as cracking and rutting, which can be proactively identified by distributed optical fiber sensing technology. However, due to the material nature of optical fibers, a bare fiber is apt to be damaged during the construction process of pavements. Thus, a protective layer is needed for this application. Unfortunately, part of the strain of the host material is absorbed by the protective layer when transferring the strain to the sensing fiber. To account for the strain transfer error, in this paper a theoretical analysis of the strain transfer of a three-layered general model has been carried out by introducing Goodman’s hypothesis to describe the interfacial shear stress relationship. The model considers the viscoelastic behavior of the host material and protective layer. The effects of one crack in the host material and the sensing length on strain transfer relationship are been discussed. To validate the effectiveness of the strain transfer analysis, a flexible asphalt-mastic packaged distributed optical fiber sensor was designed and tested in a laboratory environment to monitor the distributed strain and appearance of cracks in an asphalt concrete beam at two different temperatures. The experimental results indicated that the developed strain transfer formula can significantly reduce the strain transfer error, and that the asphalt-mastic packaged optical fiber sensor can successfully monitor the distributed strain and identify local cracks.

  11. Biosurfactant-producing strains in enhancing solubilization and biodegradation of petroleum hydrocarbons in groundwater.

    PubMed

    Liu, Hong; Wang, Hang; Chen, Xuehua; Liu, Na; Bao, Suriguge

    2014-07-01

    Three biosurfactant-producing strains designated as BS-1, BS-3, and BS-4 were screened out from crude oil-contaminated soil using a combination of surface tension measurement and oil spreading method. Thin layer chromatography and infrared analysis indicated that the biosurfactants produced by the three strains were lipopeptide, glycolipid, and phospholipid. The enhancement of solubilization and biodegradation of petroleum hydrocarbons in groundwater employing biosurfactant-producing strains was investigated. The three strain mixtures led to more solubilization of petroleum hydrocarbons in groundwater, and the solubilization rate was 10.5 mg l−1. The combination of biosurfactant-producing strains and petroleum-degrading strains exhibited a higher biodegradation efficiency of 85.4 % than the petroleum-degrading strains (71.2 %). Biodegradation was enhanced the greatest with biosurfactant-producing strains and petroleum-degrading strains in a ratio of 1:1. Fluorescence microscopy images illustrate that the oil dispersed into smaller droplets and emulsified in the presence of biosurfactant-producing strains, which attached to the oil. Thus, the biodegradation of petroleum hydrocarbons in groundwater was enhanced.

  12. [Modern Approaches to the Creation of Industrial Microorganism Strains].

    PubMed

    Debabov, V G

    2015-04-01

    Microorganism producer strains are the basis of industrial biotechnology. Their properties determine the economical parameters of the production. Methods of rational design (metabolic engineering) and combinatorial methods of mutagenesis and selection (laboratory evolution, adaptive evolution, protein and genomic shuffling) are used for the construction of microorganism strains. Combination of these methods is frequently used. Modern strains usually do not contain plasmids and markers of drug resistance. All changes are introduced into the chromosome by the methods of homologous and site-specific recombination. The sum of such approaches is called recombineering. Gene expression is carried out at the optimal level under the control of promoters of a certain power (frequently regulated). Knowledge of a complete genomic sequence is almost a mandatory condition for the use of methods of metabolic engineering. Bioinformatics significantly assists in the selection of enzymes and the search for necessary genes and metabolic reactions. Measurement of metabolic fluxes largely assists in the construction of strains. The current level of science makes it possible to construct metabolic pathways de novo in strains for the production of chemicals and biofuel. Carbon dioxide has potential as a raw material for microbiological industry; therefore, the study of CO2 fixation by acetogens and electrogens is a promising direction of studies.

  13. Investigation of cyanobacteria in a controlled hyperbolic straining flow

    NASA Astrophysics Data System (ADS)

    Akbaridoust, Farzan; Philip, Jimmy; Marusic, Ivan

    2016-11-01

    Here we report a systematic study on the effect of straining flow on cyanobacteria, which are a cause of significant water contamination issues worldwide. We focus on the species Anaebena Circinalis. A micro-cross channel equipped with two online computer-controlled on-chip membrane valves was designed and fabricated using standard soft-lithography. The device produces a hyperbolic straining flow on a micron-scaled region similar to G. I. Taylor's four-roll mill at larger scale. It was used to investigate the behaviour of a single filament of cynobacteria in a crowded medium under an increasing uniform strain rate flow. The velocity field and the resulting uniform strain-rate was measured in the absence of bacteria filaments using micro-PIV. A large number of single filaments of bacteria were trapped and exposed to stain-rates over 2 to 15 s-1. Previous studies have reported anecdotal evidence of suspected mechanical damage to Anaebena Circinalis for strain rates considerably lower than the maximum values studied here. In our case, no mechanical damage was observed. This work was performed in part at the Melbourne Centre for Nanofabrication (MCN) in the Victorian Node of the Australian National Fabrication Facility (ANFF).

  14. Time-dependent strains and stresses in a pumpkin balloon

    NASA Astrophysics Data System (ADS)

    Gerngross, T.; Xu, Y.; Pellegrino, S.

    This paper presents a study of pumpkin-shaped superpressure balloons consisting of gores made from a thin polymeric film attached to high stiffness meridional tendons This type of design is being used for the NASA ULDB balloons The gore film shows considerable time-dependent stress relaxation whereas the behaviour of the tendons is essentially time-independent Upon inflation and pressurization the instantaneous i e linear-elastic strain and stress distributions in the film show significantly higher values in the meridional direction However over time and due to the biaxial visco-elastic stress relaxation of the the gore material the em hoop strains increase and the em meridional stresses decrease whereas the em remaining strain and stress components remain substantially unchanged These results are important for a correct assessment of the structural integrity of a pumpkin balloon in a long-duration mission both in terms of the material performance and the overall stability of the shape of the balloon An experimental investigation of the time dependence of the biaxial strain distribution in the film of a 4 m diameter 48 gore pumpkin balloon is presented The inflated shape of selected gores has been measured using photogrammetry and the time variation in strain components at some particular points of these gores has been measured under constant pressure and temperature The results show good correlation with a numerical study using the ABAQUS finite-element package that includes a widely used model of

  15. Time-dependent strains and stresses in a pumpkin balloon

    NASA Technical Reports Server (NTRS)

    Gerngross, T.; Xu, Y.; Pellegrino, S.

    2006-01-01

    This paper presents a study of pumpkin-shaped superpressure balloons, consisting of gores made from a thin polymeric film attached to high stiffness, meridional tendons. This type of design is being used for the NASA ULDB balloons. The gore film shows considerable time-dependent stress relaxation, whereas the behaviour of the tendons is essentially time-independent. Upon inflation and pressurization, the "instantaneous", i.e. linear-elastic strain and stress distribution in the film show significantly higher values in the meridional direction. However, over time, and due to the biaxial visco-elastic stress relaxation of the the material, the hoop strains increase and the meridional stresses decrease, whereas the remaining strain and stress components remain substantially unchanged. These results are important for a correct assessment of the structural integrity of a pumpkin balloon in a long-duration mission, both in terms of the material performance and the overall stability of the shape of the balloon. An experimental investigation of the time dependence of the biaxial strain distribution in the film of a 4 m diameter, 48 gore pumpkin balloon is presented. The inflated shape of selected gores has been measured using photogrammetry and the time variation in strain components at some particular points of these gores has been measured under constant pressure and temperature. The results show good correlation with a numerical study, using the ABAQUS finite-element package, that includes a widely used model of the visco-elastic response of the gore material:

  16. Engineering related neutron diffraction measurements probing strains, texture and microstructure

    SciTech Connect

    Clausen, Bjorn; Brown, Donald W; Tome, Carlos N; Balogh, Levente; Vogel, Sven C

    2010-01-01

    Neutron diffraction has been used for engineering applications for nearly three decades. The basis of the technique is powder diffraction following Bragg's Law. From the measured diffraction patterns information about internal, or residual, strain can be deduced from the peak positions, texture information can be extracted from the peak intensities, and finally the peak widths can provide information about the microstructure, e.g. dislocation densities and grain sizes. The strains are measured directly from changes in lattice parameters, however, in many cases it is non-trivial to determine macroscopic values of stress or strain from the measured data. The effects of intergranular strains must be considered, and combining the neutron diffraction measurements with polycrystal deformation modeling has proven invaluable in determining the overall stress and strain values of interest in designing and dimensioning engineering components. Furthelmore, the combined use of measurements and modeling has provided a tool for elucidating basic material properties, such as critical resolved shear stresses for the active deformation modes and their evolution as a function of applied deformation.

  17. Susceptibility of Legionella strains to the chlorinated biocide, monochloramine.

    PubMed

    Jakubek, Delphine; Guillaume, Carole; Binet, Marie; Leblon, Gérard; DuBow, Michael; Le Brun, Matthieu

    2013-01-01

    Members of the Legionella genus find suitable conditions for their growth and survival in nuclear power plant cooling circuits. To limit the proliferation of Legionella pathogenic bacteria in nuclear power plant cooling circuits, and ensure that levels remain below regulatory thresholds, monochloramine treatment can be used. Although the treatment is highly effective, i.e. it reduces Legionella numbers by over 99%, Legionella bacteria can still be detected at low concentrations and rapid re-colonisation of circuits can occur after the treatment has ceased. The aim of this study was to develop an in vitro methodology for determining the intrinsic susceptibility of L. pneumophila strains, collected from various nuclear power plant cooling circuits subjected to different treatment conditions. The methodology was developed by using an original approach based on response surface methodology (RSM) combined with a multifactorial experimental design. The susceptibility was evaluated by the Ct factor. The susceptibility of environmental strains varies widely and is, for some strains, greater than that of known tolerant species; however, strain susceptibility was not related to treatment conditions. Selection pressure induced by monochloramine use did not result in the selection of more tolerant Legionella strains and did not explain the detection of Legionella during treatment or the rapid re-colonisation of cooling circuits after disinfection has ceased.

  18. Low-dimensional clustering detects incipient dominant influenza strain clusters

    PubMed Central

    He, Jiankui; Deem, Michael W.

    2010-01-01

    Influenza has been circulating in the human population and has caused three pandemics in the last century (1918 H1N1, 1957 H2N2 and 1968 H3N2). The 2009 A(H1N1) was classified by World Health Organization as the fourth pandemic. Influenza has a high evolution rate, which makes vaccine design challenging. We here consider an approach for early detection of new dominant strains. By clustering the 2009 A(H1N1) sequence data, we found two main clusters. We then define a metric to detect the emergence of dominant strains. We show on historical H3N2 data that this method is able to identify a cluster around an incipient dominant strain before it becomes dominant. For example, for H3N2 as of 30 March 2009, the method detects the cluster for the new A/British Columbia/RV1222/2009 strain. This strain detection tool would appear to be useful for annual influenza vaccine selection. PMID:21036781

  19. High strain rate mechanical properties of IM7/8551-7 graphite epoxy composite

    SciTech Connect

    Powers, B.M.; Vinson, J.R.; Hall, I.W.

    1995-12-31

    Polymer matrix composites offer excellent mechanical properties such as high specific strength and stiffness which make them attractive for many naval, aerospace and automotive structural components. Although they are candidate materials for many applications where high strain rate loading is probable, little is known of the material responses to shock loading for most composite materials. Because mechanical properties vary significantly with strain rate, the use of static properties in the analysis and design of structures which undergo dynamic loadings can on one hand lead to a very conservative overweight design, or on the other hand can lead to designs which fail prematurely and unexpectedly. The use of dynamic material properties will ensure the design of composite structures which are weight efficient and structurally sound when they are subjected to dynamic loads. In this study, a Split Hopkinson Pressure Bar is used to obtain compressive mechanical properties of a unidirectional IM7/8551-7 graphite epoxy composite. For each of the three principal directions, the yield stress, yield strain, ultimate stress, ultimate strain, modulus of elasticity, elastic strain energy function and the total strain energy to failure are presented for strain rates varying from 49 sec{sup {minus}1} to 1430 sec{sup {minus}1}. The data from 72 tests are statistically analyzed, represented by equations, and discussed in some detail.

  20. 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.

  1. 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

  2. ISOLATION AND PRELIMINARY CHARACTERISTICS OF THREE BACTERIOPHAGES ASSOCIATED WITH A LYSOGENIC STRAIN OF PSEUDOMONAS AERUGINOSA, 12

    PubMed Central

    Feary, Thomas W.; Fisher, Earl; Fisher, Thelma N.

    1964-01-01

    Feary, Thomas W. (Tulane University School of Medicine, New Orleans, La.), Earl Fisher, Jr., and Thelma N. Fisher. Isolation and preliminary characteristics of three bacteriophages associated with a lysogenic strain of Pseudomonas aeruginosa. J. Bacteriol. 87:196–208. 1964.—Three bacteriophages designated 7v, 7m, and 7s were isolated from a lysogenic strain of Pseudomonas aeruginosa designated Ps-7. The three viruses were found to be completely unrelated on the basis of plaque morphology, host range, serology, ultraviolet induction, sensitivity to heat, and particle morphology as revealed by electron microscopy. In addition, it was shown that the three phages were incapable of plaque formation on bacteria other than various strains of P. aeruginosa. Of the three phages, only phage 7v was capable of plaque formation on strain Ps-7. The growth of phage 7v on strain Ps-7 exhibited properties which suggest that this virus arises as the result of mutation in a temperate phage for which strain Ps-7 is lysogenic. Phages 7m and 7s are incapable of plaque formation on strain Ps-7, but are adsorbed at characteristic rates to cell suspensions of strain Ps-7. The relationship between phage 7m and strain Ps-7 was shown to meet the classical criteria for lysogeny. Because phage 7s contains ribonucleic acid as its nucleic acid component, it was concluded that its production by strain Ps-7 and the demonstration of immunity of strain Ps-7 to infection by phage 7s were not sufficient evidence to define the nature of the relationship between phage 7s and P. aeruginosa strain Ps-7. It was observed that under certain conditions the infectious titer of phage 7s preparations are markedly reduced in the presence of ribonuclease. Images PMID:14102854

  3. 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

  4. Retaining large and adjustable elastic strains of kilogram-scale Nb nanowires [Better Superconductor by Elastic Strain Engineering: Kilogram-scale Free-Standing Niobium Metal Composite with Large Retained Elastic Strains

    DOE PAGES

    Hao, Shijie; Cui, Lishan; Wang, Hua; ...

    2016-02-10

    Crystals held at ultrahigh elastic strains and stresses may exhibit exceptional physical and chemical properties. Individual metallic nanowires can sustain ultra-large elastic strains of 4-7%. However, retaining elastic strains of such magnitude in kilogram-scale nanowires is challenging. Here, we find that under active load, ~5.6% elastic strain can be achieved in Nb nanowires in a composite material. Moreover, large tensile (2.8%) and compressive (-2.4%) elastic strains can be retained in kilogram-scale Nb nanowires when the composite is unloaded to a free-standing condition. It is then demonstrated that the retained tensile elastic strains of Nb nanowires significantly increase their superconducting transitionmore » temperature and critical magnetic fields, corroborating ab initio calculations based on BCS theory. This free-standing nanocomposite design paradigm opens new avenues for retaining ultra-large elastic strains in great quantities of nanowires and elastic-strain-engineering at industrial scale.« less

  5. Strain-Detecting Composite Materials

    NASA Technical Reports Server (NTRS)

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

    2016-01-01

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

  6. Development of a strain-specific genomic marker for monitoring a Bacillus subtilis biocontrol strain in the rhizosphere of tomato.

    PubMed

    Felici, Cristiana; Vettori, Lorenzo; Toffanin, Annita; Nuti, Marco

    2008-08-01

    A strain-specific molecular marker enabling the detection and tracking of the biological control agent Bacillus subtilis 101, when released into the environment, was developed. Random amplified polymorphic DNA (RAPD) technique was used to differentiate this from other B. subtilis strains. A differentially amplified fragment obtained from RAPD profiles was sequenced and characterized as sequence-characterized amplified region (SCAR) marker, and four primer pairs were designed and evaluated for their specificity towards this strain. The sensibility of the selected SCAR primer pair was evaluated by qualitative PCR and Southern blotting, and the detection limit was assessed around 10(2) CFU (g dry wt soil)(-1), thus providing a reliable tool for the traceability of this B. subtilis strain in greenhouse or field trials. A plating assay coupled to PCR with the SCAR primer pair was then used as a detection method in microcosm experiments for monitoring the population of B. subtilis 101 in the rhizosphere of tomato, grown under two different soil conditions, i.e. nonsterile peat-based substrate and sandy-loam agricultural soil, respectively. The data of rhizosphere colonization indicated that the soil conditions significantly affected the rhizosphere establishment of strain 101.

  7. 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 ...

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. Phenotypic, antigenic, and molecular characterization of Pasteurella piscicida strains isolated from fish.

    PubMed Central

    Magariños, B; Romalde, J L; Bandín, I; Fouz, B; Toranzo, A E

    1992-01-01

    We compared Pasteurella piscicida strains isolated from different fish species in several European countries with strains isolated in Japan and the United States. The taxonomic analysis revealed that, regardless of the geographic origin and source of isolation, all the strains exhibited the same biochemical and physiological characteristics. Serological assays with different rabbit antisera demonstrated a high level of antigenic similarity among strains, with cross-agglutination titers of 20,480 to 40,960. This serological homogeneity was supported by the lipopolysaccharide (LPS) and membrane protein profiles. All the P. piscicida strains had the same electrophoretic LPS pattern, showing O side chains with a ladder-like structure, and shared at least four major outer membrane proteins, of 20, 30, 42, and 53 kDa. Western blot (immunoblot) analysis with LPS and protein indicated that all the P. piscicida strains are immunologically related. In addition, the chromosomal DNA fingerprint patterns obtained for the European strains with the enzymes EcoRI and BamHI were practically identical to those of the Japanese and U.S. strains. Although some differences were found in the plasmid profiles of P. piscicida, a large number of strains possessed in common plasmid bands of 20 and 7 MDa. In addition, a plasmid of 50 MDa was present in the majority of the European strains. Restriction endonuclease analysis demonstrated the genetic homology of the plasmid bands shared by most of the European strains. All the P. piscicida strains had the same drug resistance patterns, indicating that a correlation between plasmid carriage and resistance to a specific antimicrobial agent cannot be established. The high levels of phenotypic, serological, and genetic homogeneity found among the P. piscicida strains should facilitate the development of DNA probes with diagnostic purposes as well as the design of effective vaccines. Images PMID:1444366

  14. Phenotypic, antigenic, and molecular characterization of Pasteurella piscicida strains isolated from fish.

    PubMed

    Magariños, B; Romalde, J L; Bandín, I; Fouz, B; Toranzo, A E

    1992-10-01

    We compared Pasteurella piscicida strains isolated from different fish species in several European countries with strains isolated in Japan and the United States. The taxonomic analysis revealed that, regardless of the geographic origin and source of isolation, all the strains exhibited the same biochemical and physiological characteristics. Serological assays with different rabbit antisera demonstrated a high level of antigenic similarity among strains, with cross-agglutination titers of 20,480 to 40,960. This serological homogeneity was supported by the lipopolysaccharide (LPS) and membrane protein profiles. All the P. piscicida strains had the same electrophoretic LPS pattern, showing O side chains with a ladder-like structure, and shared at least four major outer membrane proteins, of 20, 30, 42, and 53 kDa. Western blot (immunoblot) analysis with LPS and protein indicated that all the P. piscicida strains are immunologically related. In addition, the chromosomal DNA fingerprint patterns obtained for the European strains with the enzymes EcoRI and BamHI were practically identical to those of the Japanese and U.S. strains. Although some differences were found in the plasmid profiles of P. piscicida, a large number of strains possessed in common plasmid bands of 20 and 7 MDa. In addition, a plasmid of 50 MDa was present in the majority of the European strains. Restriction endonuclease analysis demonstrated the genetic homology of the plasmid bands shared by most of the European strains. All the P. piscicida strains had the same drug resistance patterns, indicating that a correlation between plasmid carriage and resistance to a specific antimicrobial agent cannot be established. The high levels of phenotypic, serological, and genetic homogeneity found among the P. piscicida strains should facilitate the development of DNA probes with diagnostic purposes as well as the design of effective vaccines.

  15. Strains around distally inclined implants retaining mandibular overdentures with Locator attachments: an in vitro study

    PubMed Central

    Setta, Fathi Abo; Khirallah, Ahmed Samir

    2016-01-01

    PURPOSE The aim of the present study was to evaluate, by means of strain gauge analysis, the effect of different implant angulations on strains around two implants retaining mandibular overdenture with Locator attachments. MATERIALS AND METHODS Four duplicate mandibular acrylic models were constructed. Two implants were inserted in the canine regions using the following degrees of distal inclinations: group I (control); 0°, group II; 10°, group III; 20°, and group IV; 30°. Locator pink attachments were used to connect the overdenture to the implants and Locator red (designed for severely angled implants) was used for group IV (group IVred). For each group, two linear strain gauges were attached at the mesial and distal surfaces of the acrylic resin around each implant. Peri-implant strain was measured on loading and non-loading sides during bilateral and unilateral loading. RESULTS For all groups, the mesial surfaces of the implants at loading and non-loading sides experienced compressive (negative) strains, while the distal implant surfaces showed tensile (positive) strains. Group IV showed the highest strain, followed by group III, group II. Both group I and group IVred showed the lowest strain. The strain gauges at the mesial surface of the loading side recorded the highest strain, and the distal surface at non-loading side showed the lowest strain. Unilateral loading recorded significantly higher strain than bilateral loading. CONCLUSION Peri-implant strains around two implants used to retain mandibular overdentures with Locator attachments increase as distal implant inclination increases, except when red nylon inserts were used. PMID:27141255

  16. 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

  17. 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

  18. Phenotypic and Genotypic Description of Sedimenticola selenatireducens Strain CUZ, a Marine (Per)Chlorate-Respiring Gammaproteobacterium, and Its Close Relative the Chlorate-Respiring Sedimenticola Strain NSS

    PubMed Central

    Carlström, Charlotte I.; Loutey, Dana E.; Wang, Ouwei; Engelbrektson, Anna; Clark, Iain; Lucas, Lauren N.; Somasekhar, Pranav Y.

    2015-01-01

    Two (per)chlorate-reducing bacteria, strains CUZ and NSS, were isolated from marine sediments in Berkeley and San Diego, CA, respectively. Strain CUZ respired both perchlorate and chlorate [collectively designated (per)chlorate], while strain NSS respired only chlorate. Phylogenetic analysis classified both strains as close relatives of the gammaproteobacterium Sedimenticola selenatireducens. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) preparations showed the presence of rod-shaped, motile cells containing one polar flagellum. Optimum growth for strain CUZ was observed at 25 to 30°C, pH 7, and 4% NaCl, while strain NSS grew optimally at 37 to 42°C, pH 7.5 to 8, and 1.5 to 2.5% NaCl. Both strains oxidized hydrogen, sulfide, various organic acids, and aromatics, such as benzoate and phenylacetate, as electron donors coupled to oxygen, nitrate, and (per)chlorate or chlorate as electron acceptors. The draft genome of strain CUZ carried the requisite (per)chlorate reduction island (PRI) for (per)chlorate respiration, while that of strain NSS carried the composite chlorate reduction transposon responsible for chlorate metabolism. The PRI of strain CUZ encoded a perchlorate reductase (Pcr), which reduced both perchlorate and chlorate, while the genome of strain NSS included a gene for a distinct chlorate reductase (Clr) that reduced only chlorate. When both (per)chlorate and nitrate were present, (per)chlorate was preferentially utilized if the inoculum was pregrown on (per)chlorate. Historically, (per)chlorate-reducing bacteria (PRB) and chlorate-reducing bacteria (CRB) have been isolated primarily from freshwater, mesophilic environments. This study describes the isolation and characterization of two highly related marine halophiles, one a PRB and the other a CRB, and thus broadens the known phylogenetic and physiological diversity of these unusual metabolisms. PMID:25662971

  19. Phenotypic and genotypic description of Sedimenticola selenatireducens strain CUZ, a marine (per)chlorate-respiring gammaproteobacterium, and its close relative the chlorate-respiring Sedimenticola strain NSS.

    PubMed

    Carlström, Charlotte I; Loutey, Dana E; Wang, Ouwei; Engelbrektson, Anna; Clark, Iain; Lucas, Lauren N; Somasekhar, Pranav Y; Coates, John D

    2015-04-01

    Two (per)chlorate-reducing bacteria, strains CUZ and NSS, were isolated from marine sediments in Berkeley and San Diego, CA, respectively. Strain CUZ respired both perchlorate and chlorate [collectively designated (per)chlorate], while strain NSS respired only chlorate. Phylogenetic analysis classified both strains as close relatives of the gammaproteobacterium Sedimenticola selenatireducens. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) preparations showed the presence of rod-shaped, motile cells containing one polar flagellum. Optimum growth for strain CUZ was observed at 25 to 30 °C, pH 7, and 4% NaCl, while strain NSS grew optimally at 37 to 42 °C, pH 7.5 to 8, and 1.5 to 2.5% NaCl. Both strains oxidized hydrogen, sulfide, various organic acids, and aromatics, such as benzoate and phenylacetate, as electron donors coupled to oxygen, nitrate, and (per)chlorate or chlorate as electron acceptors. The draft genome of strain CUZ carried the requisite (per)chlorate reduction island (PRI) for (per)chlorate respiration, while that of strain NSS carried the composite chlorate reduction transposon responsible for chlorate metabolism. The PRI of strain CUZ encoded a perchlorate reductase (Pcr), which reduced both perchlorate and chlorate, while the genome of strain NSS included a gene for a distinct chlorate reductase (Clr) that reduced only chlorate. When both (per)chlorate and nitrate were present, (per)chlorate was preferentially utilized if the inoculum was pregrown on (per)chlorate. Historically, (per)chlorate-reducing bacteria (PRB) and chlorate-reducing bacteria (CRB) have been isolated primarily from freshwater, mesophilic environments. This study describes the isolation and characterization of two highly related marine halophiles, one a PRB and the other a CRB, and thus broadens the known phylogenetic and physiological diversity of these unusual metabolisms.

  20. Influence of strain on the structural instabilities and functional properties of complex oxides

    NASA Astrophysics Data System (ADS)

    Hatt, Alison J.

    Complex oxides display a tremendous array of functional properties, ranging from ferroelectricity to giant magnetoresistance to superconductivity. Epitaxial strain in thin films of these materials provides a tool to further manipulate the available functionalities and presents an attractive avenue for material design. Arising from mismatch between films and substrate lattice parameters, strain can have profound effects on material properties by altering the energy balance between competing structural instabilities. Here we use density functional calculations to address the influence of strain on ABO 3 perovskite oxides, examining the impact on structural instabilities and focusing on regions in which strain induces phase transition phenomena. The density functional approach gives us access to the atomic-level details of a material's response to strain, enabling us to disentangle competing instabilities and differentiate between the ionic, electronic and lattice responses. In particular, we seek to illuminate the coupling of strain to distortion modes involving rigid rotations of the BO6 octahedral units. These octahedral rotations are known to drive or prohibit a number of strain-induced phenomena in functional oxides, but the details of their coupling to strain were not previously well understood. We develop our topic through investigations on four perovskite systems. We first study a layered superlattice of La(Al,Fe,Cr)O3, to distinguish the effect of misfit strain from the symmetry constraint imposed by heterostructuring. We then focus on the influence of strain in a series of single-phase perovskites of increasing complexity. In the simple dielectric LaAlO3, we isolate the strain-rotation coupling, develop a model for the dependence of rotations on bi-axial and uni-axial strain, and characterize a previously unidentified strain-induced phase transition. Next, we address strain in a polar material, multiferroic BiFeO3, to investigate recent experimental reports

  1. 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.

  2. EDITORIAL: Excelling under strain: band engineering in nanomaterials Excelling under strain: band engineering in nanomaterials

    NASA Astrophysics Data System (ADS)

    Demming, Anna

    2013-08-01

    A little stress or strain has been known to improve the performance of athletes, actors and of course nanomaterials alike. In fact strain in silicon is now a major engineering tool for improving the performance of devices, and is ubiquitously used in device design and fabrication. Strain engineering alters a material's band structure, a model of electron behaviour that describes how as atoms come together in a solid, their discrete electron orbitals overlap to ultimately give rise to bands of allowed energy levels. In a strained crystal lattice of silicon or silicon germanium the distance between atoms in the lattice is greater than usual and the bands of allowed energy levels change. This July marks 100 years since Bohr submitted his paper 'On the constitution of atoms and molecules' [1] where he describes the structure of the atom in terms of discrete allowed energy levels. The paper was a seminal contribution to the development of quantum mechanics and laid the initial theoretical precepts for band gap engineering in devices. In this issue Nrauda and a collaboration of researchers in Europe and Australia study the growth of defect-free SiGe islands on pre-patterned silicon [2]. They analyse the strain in the islands and determine at what point lattice dislocations set in with a view to informing implementation of strain engineering in devices. The effects of strain on band structure in silicon and germanium were already studied and reported in the 1950s [3, 4]. Since then the increasing focus on nanoscale materials and the hunger for control of electronic properties has prompted further study of strain effects. The increased surface area to volume ratio in nanostructures changes the strain behaviour with respect to bulk materials, and this can also be exploited for handling and fine tuning strain to manipulate material properties. It is perhaps no surprise that graphene, one of the most high-profile materials in current nanotechnology research, has attracted

  3. Design optimization of transonic airfoils

    NASA Technical Reports Server (NTRS)

    Joh, C.-Y.; Grossman, B.; Haftka, R. T.

    1991-01-01

    Numerical optimization procedures were considered for the design of airfoils in transonic flow based on the transonic small disturbance (TSD) and Euler equations. A sequential approximation optimization technique was implemented with an accurate approximation of the wave drag based on the Nixon's coordinate straining approach. A modification of the Euler surface boundary conditions was implemented in order to efficiently compute design sensitivities without remeshing the grid. Two effective design procedures producing converged designs in approximately 10 global iterations were developed: interchanging the role of the objective function and constraint and the direct lift maximization with move limits which were fixed absolute values of the design variables.

  4. First International Symposium on Strain Gauge Balances. Part 2

    NASA Technical Reports Server (NTRS)

    Tripp, John S (Editor); Tcheng, Ping (Editor)

    1999-01-01

    The first International Symposium on Strain Gauge Balances was sponsored and held at NASA Langley Research Center during October 22-25, 1996. The symposium provided an open international forum for presentation, discussion, and exchange of technical information among wind tunnel test technique specialists and strain gauge balance designers. The Symposium also served to initiate organized professional activities among the participating and relevant international technical communities. Over 130 delegates from 15 countries were in attendance. The program opened with a panel discussion, followed by technical paper sessions, and guided tours of the National Transonic Facility (NTF) wind tunnel, a local commercial balance fabrication facility, and the LaRC balance calibration laboratory. The opening panel discussion addressed "Future Trends in Balance Development and Applications." Forty-six technical papers were presented in 11 technical sessions covering the following areas: calibration, automatic calibration, data reduction, facility reports, design, accuracy and uncertainty analysis, strain gauges, instrumentation, balance design, thermal effects, finite element analysis, applications, and special balances. At the conclusion of the Symposium, a steering committee representing most of the nations and several U.S. organizations attending the Symposium was established to initiate planning for a second international balance symposium, to be held in 1999 in the UK.

  5. First International Symposium on Strain Gauge Balances. Pt. 1

    NASA Technical Reports Server (NTRS)

    Tripp, John S. (Editor); Tcheng, Ping (Editor)

    1999-01-01

    The first International Symposium on Strain Gauge Balances was sponsored and held at NASA Langley Research Center during October 22-25, 1996. The symposium provided an open international forum for presentation, discussion, and exchange of technical information among wind tunnel test technique specialists and strain gauge balance designers. The Symposium also served to initiate organized professional activities among the participating and relevant international technical communities. Over 130 delegates from 15 countries were in attendance. The program opened with a panel discussion, followed by technical paper sessions, and guided tours of the National Transonic Facility (NTF) wind tunnel, a local commercial balance fabrication facility, and the LaRC balance calibration laboratory. The opening panel discussion addressed "Future Trends in Balance Development and Applications." Forty-six technical papers were presented in 11 technical sessions covering the following areas: calibration, automatic calibration, data reduction, facility reports, design, accuracy and uncertainty analysis, strain gauges, instrumentation, balance design, thermal effects, finite element analysis, applications, and special balances. At the conclusion of the Symposium, a steering committee representing most of the nations and several U.S. organizations attending the Symposium was established to initiate planning for a second international balance symposium, to be held in 1999 in the UK.

  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. Genetic diversity of Hungarian canine distemper virus strains.

    PubMed

    Demeter, Zoltán; Lakatos, Béla; Palade, Elena Alina; Kozma, Tamás; Forgách, Petra; Rusvai, Miklós

    2007-06-21

    To achieve proper diagnosis of dogs based on acute clinical symptoms and poorly preserved field samples taken from animals that died due to canine distemper (CD), a new differential diagnostic test has been developed based on polymerase chain reaction (PCR). In this study, more than 150 samples collected from dogs showing respiratory, gastrointestinal and neurological signs suggesting canine distemper virus (CDV) infection were examined. The samples consisted of urine, blood and nasal swabs collected from clinically ill patients, sent to our laboratory by clinicians from various veterinary clinics throughout Hungary. Various organs collected during the necropsy of dogs with pathological changes that suggested CDV infection were also included. Three distinct PCRs were designed. For diagnostic purposes, a primer pair specific to a 409 bases-long segment within the conservative part of the large polymerase region (L) of the CDV genome was designed. Using this test, out of the 150 analyzed samples, 46 (30.66%) proved to be positive for CDV, indicating that CDV still represents a high risk to the canine population in Hungary. For the phylogenetical analysis, a primer pair that completely encompasses the hemagglutinin (H) gene of the CDV genome was designed. The amplicons of this region were sequenced in both directions using the appropriate primers. Our results indicate that several different CDV genotypes are currently present in Hungary. Nine of the analyzed Hungarian strains turned out to belong to the so-called Arctic group of CDVs, and were most closely related to non-European strains from North America, China and Greenland, as well as to the phocine distemper virus 2 (PDV-2) isolated from Baikal seals (Phoca sibirica). One of the Hungarian strains showed high similarity to other European isolates from Denmark, Germany, Italy and Turkey, as well as to other isolates from geographically more distant regions, such as the USA. Three Hungarian strains seem to join a

  11. Mechanisms of strain-mediated mesenchymal stem cell apoptosis.

    PubMed

    Kearney, E M; Prendergast, P J; Campbell, V A

    2008-12-01

    Mechanical conditioning of mesenchymal stem cells (MSCs) has been adopted widely as a biophysical signal to aid tissue engineering applications. The replication of in vivo mechanical signaling has been used in in vitro environments to regulate cell differentiation, and extracellular matrix synthesis, so that both the chemical and mechanical properties of the tissue-engineered construct are compatible with the implant site. While research in these areas contributes to tissue engineering, the effects of mechanical strain on MSC apoptosis remain poorly defined. To evaluate the effects of uniaxial cyclic tensile strain on MSC apoptosis and to investigate mechanotransduction associated with strain-mediated cell death, MSCs seeded on a 2D silicone membrane were stimulated by a range of strain magnitudes for 3 days. Mechanotransduction was investigated using the stretch-activated cation channel blocker gadolinium chloride, the L-type voltage-activated calcium channel blocker nicardipine, the c-jun NH(2)-terminal kinase (JNK) blocker D-JNK inhibitor 1, and the calpain inhibitor MDL 28170. Apoptosis was assessed through DNA fragmentation using the terminal deoxynucleotidyl transferase mediated-UTP-end nick labeling method. Results demonstrated that tensile strains of 7.5% or greater induce apoptosis in MSCs. L-type voltage-activated calcium channels coupled mechanical stress to activation of calpain and JNK, which lead to apoptosis through DNA fragmentation. The definition of the in vitro boundary conditions for tensile strain and MSCs along with a proposed mechanism for apoptosis induced by mechanical events positively contributes to the development of MSC biology, bioreactor design for tissue engineering, and development of computational methods for mechanobiology.

  12. 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.

  13. Differentiation of strains in Mycobacterium tuberculosis complex by DNA sequence polymorphisms, including rapid identification of M. bovis BCG.

    PubMed Central

    Frothingham, R

    1995-01-01

    The Mycobacterium tuberculosis complex includes M. tuberculosis, M. bovis, M. microti, and M. africanum. Seven strains of the M. tuberculosis complex were sequenced in a region of about 300 bp which contains multiple 15-bp tandem repeats and which is part of a 1,551-bp open reading frame. Four distinct sequences were obtained, each defining a sequevar. A sequevar includes the strain or strains with a given sequence. The type strain M. tuberculosis TMC 102 (H37Rv) was designated sequevar MED-G. When compared to MED-G, sequevar LONG had an insertion of one 15-bp tandem repeat and sequevar SHORT had a deletion of one tandem repeat. Sequevar MED-C had a G-->C substitution, coding for the conservative change Ser-->Thr. BanI cuts only sequevar MED-C at the site of the substitution. PCR-restriction enzyme analysis was used to determine the sequevars of 92 M. tuberculosis complex strains. All 23 M. bovis BCG strains belonged to sequevar MED-C. The M. africanum type strain was sequevar SHORT. The remaining 68 strains of M. tuberculosis, M. bovis (not BCG), and M. microti were sequevars LONG (3 strains) or MED-G (65 strains). PCR-restriction enzyme analysis was applied to reference strains and clinical isolates with a worldwide distribution. This method provides rapid, sensitive, and specific identification of the important vaccine strain M. bovis BCG. PMID:7790448

  14. Early history of laboratory breeding of Aedes aegypti (Diptera: Culicidae) focusing on the origins and use of selected strains.

    PubMed

    Kuno, Goro

    2010-11-01

    The yellow fever mosquito, Aedes aegypti (L.) (Diptera: Culicidae), is well recognized for its extensive adaptation to diverse ecological conditions and for genetic variation. Recognizing the importance of strain variation of this mosquito, researchers have established a large number of laboratory strains. Some of the popular strains have been used for research for years in many laboratories around the world. However, the exact origins of many of these strains are unknown. In this review, publications and archival records were examined to report the early laboratory mosquito rearing practices around the world and to identify the origins of selected strains. The records showed that inter-laboratory sharing of strains was already underway in the early part of the 20th century because of the ease of breeding Ae. aegypti and of sending eggs by mail. It also was found that the four strains established in major U.S. institutions by the mid-1930s, including the "ROCK" (short for Rockefeller) strain, had been derived from Cuba, Nigeria, Philippines, or Puerto Rico, all known for a long history of transmission of yellow fever virus or dengue virus rather than from North America. The strains used for research in Europe were primarily derived from West Africa, but strains of Asian, Caribbean, and South American origins also were used for comparative experiments among geographic strains. Neglected issues related to strain designation and original source identification in scientific publications were found and their relevance to current research is discussed.

  15. Demonstration Using Field Collections that Argentina Fall Armyworm Populations Exhibit Strain-specific Host Plant Preferences.

    PubMed

    Murúa, M Gabriela; Nagoshi, Rodney N; Dos Santos, Daniel A; Hay-Roe, Mirian M; Meagher, Robert L; Vilardi, J C

    2015-10-01

    Spodoptera frugiperda, the fall armyworm, is a major economic pest throughout the Western Hemisphere of corn (maize), cotton, sorghum, and a variety of agricultural grasses and vegetable crops. Studies in the United States, the Caribbean, and Brazil demonstrated the existence of two subpopulations (previously designated "host strains") that differ in their choice of plant host. Specifically, the corn strain is preferentially found in corn and sorghum, while the rice strain is dominant in rice, turf grass, and alfalfa. However, inconsistent results were reported in surveys of fall armyworm in Argentina, with some indicating that the host plant preferences of the two strains might be compromised or even nonexistent. If correct, this would complicate efforts to control this pest by considerably expanding the range of habitats that would have to be considered as potential sources for fall armyworm infestations in specific crops. A reexamination of Argentine fall armyworm, this time with field collections rather than the laboratory colonies used in previous studies, confirmed the existence of the two strains and their host preferences. Specifically, the corn strain was consistently the majority population infesting corn and was usually so in sorghum, while the rice strain was predominant in pasture/turf grasses and alfalfa. The one outlier was a collection from rice, which had a corn strain majority. Overall, the data were generally consistent with strain behaviors observed in other areas of the Western Hemisphere.

  16. Systemic neonatal candidosis: the karyotyping of Candida albicans strains isolated from neonates and health-workers.

    PubMed

    Ben Abdeljelil, J; Ben Saida, N; Saghrouni, F; Fathallah, A; Boukadida, J; Sboui, H; Ben Said, M

    2010-01-01

    Candida albicans has become an important cause of nosocomial infections in neonatal intensive care units (NICUs). The aim of the present study was to compare C. albicans strains isolated from neonates (NN) suffering from systemic candidosis and from nurses in order to determine the relatedness between NN and health workers' strains. Thirty-one C. albicans strains were isolated from 18 NN admitted to the NICU of the neonatology service of Farhat Hached Hospital of Sousse, Tunisia and suffering from systemic candidosis, together with five strains recovered from nurses suffering from C. albicans onychomycosis. Two additional strains were tested, one from an adult patient who developed a systemic candidosis and the second from an adult with inguinal intertrigo. All strains were karyotyped by pulsed-field gel electrophoresis (PFGE) with a CHEF-DR II system. Analysis of PFGE patterns yielded by the 38 strains tested led to the identification of three pulsotypes that were designated I, II and III, and consisted of six chromosomal bands with a size ranging from 700 to >2500 kbp. The most widespread was the pulsotype I, which was shared by 17 NN and the five nurses' strains. The identity between NN and nurses' strains is very suggestive of a nosocomial acquisition from health-workers.

  17. Electronic Raman scattering as an ultra-sensitive probe of strain effects in semiconductors

    SciTech Connect

    Fluegel., Brian; Mialitsin, Aleksej V.; Beaton, Daniel A.; Reno, John L.; Mascarenhas, Angelo

    2015-05-28

    Semiconductor strain engineering has become a critical feature of high-performance electronics because of the significant device performance enhancements that it enables. These improvements, which emerge from strain-induced modifications to the electronic band structure, necessitate new ultra-sensitive tools to probe the strain in semiconductors. Here, we demonstrate that minute amounts of strain in thin semiconductor epilayers can be measured using electronic Raman scattering. We also applied this strain measurement technique to two different semiconductor alloy systems using coherently strained epitaxial thin films specifically designed to produce lattice-mismatch strains as small as 10-4. Thus, comparing our strain sensitivity and signal strength in AlxGa 1-x As with those obtained using the industry-standard technique of phonon Raman scattering, we found that there was a sensitivity improvement of 200-fold and a signal enhancement of 4 × 103, thus obviating key constraints in semiconductor strain metrology.

  18. Characterization of a triple-recombinant, reassortant rotavirus strain from the Dominican Republic.

    PubMed

    Esona, Mathew D; Roy, Sunando; Rungsrisuriyachai, Kunchala; Sanchez, Jacqueline; Vasquez, Lina; Gomez, Virgen; Rios, Lourdes Aviles; Bowen, Michael D; Vazquez, Marietta

    2017-02-01

    We report the genome of a novel human triple-recombinant G4P[6-8_R] mono-reassortant strain identified in a stool sample from the Dominican Republic during routine facility-based rotavirus strain surveillance. The strain was designated as RVA/Human-wt/DOM/2013840364/2013/G4P[6-8_R], with a genomic constellation of G4-P[6-8_R]-I1-R1-C1-M1-(A1-A8_R)-N1-(T1-T7_R)-E1-H1. Recombinant gene segments NSP1 and NSP3 were generated as a result of recombination between genogroup 1 rotavirus A1 human strain and a genotype A8 porcine strain and between genogroup 1 rotavirus T1 human strain and a genotype T7 bovine strain, respectively. Analyses of the RNA secondary structures of gene segment VP4, NSP1 and NSP3 showed that all the recombinant regions appear to start in a loop (single-stranded) region and terminate in a stem (double-stranded) structure. Also, the VP7 gene occupied lineage VII within the G4 genotypes consisting of mostly porcine or porcine-like G4 strains, suggesting the occurrence of reassortment. The remaining gene segments clustered phylogenetically with genogroup 1 strains. This exchange of whole or partial genetic materials between rotaviruses by recombination and reassortment contributes directly to their diversification, adaptation and evolution.

  19. [Development of genetically stable recombinant Saccharomyces cerevisiae strains using combinational chromosomal integration].

    PubMed

    Zuo, Qi; Zhao, Xinqing; Liu, Haijun; Hu, Shiyang; Ma, Zhongyi; Bai, Fengwu

    2014-04-01

    Chromosomal integration enables stable phenotype and therefore has become an important strategy for breeding of industrial Saccharomyces cerevisiae strains. pAUR135 is a plasmid that enables recycling use of antibiotic selection marker, and once attached with designated homologous sequences, integration vector for stable expression can be constructed. Development of S. cerevisiae strains by metabolic engineering normally demands overexpression of multiple genes, and employing pAUR135 plasmid, it is possible to construct S. cerevisiae strains by combinational integration of multiple genes in multiple sites, which results in different ratios of expressions of these genes. Xylose utilization pathway was taken as an example, with three pAUR135-based plasmids carrying three xylose assimilation genes constructed in this study. The three genes were sequentially integrated on the chromosome of S. cerevisiae by combinational integration. Xylose utilization rate was improved 24.4%-35.5% in the combinational integration strain comparing with that of the control strain with all the three genes integrated in one location. Strain improvement achieved by combinational integration is a novel method to manipulate multiple genes for genetic engineering of S. cerevisiae, and the recombinant strains are free of foreign sequences and selection markers. In addition, stable phenotype can be maintained, which is important for breeding of industrial strains. Therefore, combinational integration employing pAUR135 is a novel method for metabolic engineering of industrial S. cerevisiae strains.

  20. Isolation and in vitro selection of actinomycetes strains as potential probiotics for aquaculture

    PubMed Central

    Bernal, Milagro García; Campa-Córdova, Ángel Isidro; Saucedo, Pedro Enrique; González, Marlen Casanova; Marrero, Ricardo Medina; Mazón-Suástegui, José Manuel

    2015-01-01

    Aim: This study was designed to describe a series of in vitro tests that may aid the discovery of probiotic strains from actinomycetes. Materials and Methods: Actinomycetes were isolated from marine sediments using four different isolation media, followed by antimicrobial activity and toxicity assessment by the agar diffusion method and the hemolysis of human blood cells, respectively. Extracellular enzymatic production was monitored by the hydrolysis of proteins, lipids and carbohydrates. Tolerance to different pH values and salt concentrations was also determined, followed by hydrophobicity analysis and genetic identification of the most promising strains. Results: Five out of 31 isolated strains showed antimicrobial activity against three Vibrio species. Three non-hemolytic strains (N7, RL8 and V4) among these active isolates yielded positive results in hydrophobicity tests and exhibited good growth at salt concentrations ranging from 0% to 10%, except strain RL8, which required a salt concentration >0.6%. Although these strains did not grow at pH<3, they showed different enzymatic activities. Phylogenetic analysis revealed that strains N7 and V4 have more than 99% identity with several Streptomyces species, whereas the closest matches to strain RL8 are Streptomyces panacagri and Streptomyces flocculus, with 98% and 98.2% similarity, respectively. Conclusion: Three actinomycetes strains showing probiotic-like properties were discovered using several in vitro tests that can be easily implemented in different institutions around the world. PMID:27047067